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Home My WebLink AboutSHP Draft license application Vol 1 Exhibit A 1985BEFORE THE FEDERAL ENERGY REGUL TORY COMMISSION APPLICAT ON FOR LICENSE FOR MAJOR PROJECT SUSITNA HYDROELECTR C PROJECT VOLUME 1 DRAF EXHIBIT A ~~~~ SUSITNA JOINT VENTURE ~====Alaska Power Authority ======~ '-I I I ] ~I I I I ,I -II- I I I BEFORE THE FEDERAL ENERGY REGULATORY COMMISSION APPLICATION FOR LICENSE FOR MAJOR PROJECT SUSITNA HYDROELECTRIC PROJECT DRAFT LICENSE APPLICATION VOLUME 1 EXHIBIT A PROJECT DESCRIPTION ARLIS Alaska Resources Library &Infonnat1<tn ServlCes Anchorage,Alaska November 1985 TI< 1~'1-5 ~s <Z F471 J.t.,Z>.'3 '-/2.5 ,'~}.~}~\(~;'J<,:I fi::.:~t1."~r;-'~jf,f :t,\I"~;)'!"~~ ,~~li,i,~;,.';'\,;t_~...'~·;!;";14"\ I ~ I 1 I I -j I j I I J -j -I I ) _1 I [ 1 ~J INITIAL STATEMENT ) ) ) ) ) ) ) J I - J ) .-J .) j I -) 1. 2. BEFORE THE FEDERAL ENERGY REGULATORY COMMISSION: APPLICATION FOR LICENSE FOR A MAJOR UNCONSTRUCTED PROJECT OR MAJOR MODIFIED PROJECT The Alaska Power Authority applies to the Federal Energy Regula- tory Commission for a licnese for the Susitna Hydroelectric Water Power Project,as described in the attached exhibits. The location of the proposed project is: State: Borough: Stream or other Body of Water: Alaska Matanuska-Susitna Susitna River I, I 3.The exact name,business address and telephone number of the applicant is: Alaska Power Authority 334 West 5th Avenue Anchorage,Alaska 99501 (907)276-0001 The exact names,business addresses and telephone numbers of the persons authorized to act as agents for the applicant in this application are: Mr.James B.Dischinger Project Manager Alaska Power Authority 334 West 5th Avenue Anchorage,Alaska 99501 (907)276-0001 and Charles B.Curtis,Esq. Van Ness,Feldman,sutcliffe &Curtis 1050 Thomas Jefferson Street,NW Seventh Floor Washington,D.C.20007 (202)331-9400 4.The applicant is a public corporation of the State of Alaska ~n the Department of Commerce and Economic Development but with separate and independent legal existence. 5.(i)The statutory or regulatory requirements of the state in which the project would be located and that affect the project as 851025 1 -I' ) 1 j ,I 1 -I -I ~l proposed with respect to bed and banks and to the appropriation, diversion,and use of water for power purposes,and with respect to the right to engage in the business of developing,trans- mitting,and distributing po~er and in any other business necessary to accomplish the purposes of the license under the Federal Power Act,are: (A)ALASKA STAT.§§44.83.010-44.83.425 (1984)(IIAlaska Power Authorityll)(including §§44.83.300-44.83.360,entitled IIS us itna River Hydroelectric Project ll );ALASKA ADMIN. CODE,tit.3,§94.0l0-94.900 (Apr.1982). These statutory provisions and regulations establish the Alaska Power Authority as a legal entity,the purpose of which is lito promote,develop and advance the general prosperity and economic welfare of the people'of Alaska by providing a means of constructing,acquiring,financing and operating power projects,II including hydroelectric facilities.ALASKA STAT.§§44.83.070 (1)(1984).The Alaska Power Authority has a number of specific powers,including (1)the right to perform reconnaissance studies, feasibility studies,and engineering and design with respect to power projects,2)the right to enter into contracts,(3)the right to issue bonds,(4)the right to exercise the power of eminent domain and (5)the right to construct and operate power projects.See ALASKA STAT.§§44.83.080 (1984). Sections 44.83.300-44.83.360 deal specifically witb the Susitna River Hydroelectric Project,the purpose of which is to generate, transmit and distribute electric power in a manner that will (1) minimize market area electrical power costs,(2)minimize adverse environmental and social impacts while enhancing environmental values to the extent possible and (3)safeguard both life and property.ALASKA STAT.§§44.83.300-44.83.3l0 (1984).The Alaska Power Authority is permitted to contract for preliminary work on the Susitna Project (including preparation of plans and studies, preparation and submission of license applications,and other types of ,work necessary before actual construction of the project can begin)without seeking state legislative approval.See ALASKA STAT.§§44.83.325 (1984)(Editor's note).Additionally,the Alaska Power Authority is required to obtain approval by the state legislature of its preliminary report on the Susitna Project,as provided in ALASKA STAT.§§44.83.325 (1984)before contracting for preparation of the site or contracting for actual construction of the project.See Alaska Sess.Laws,Ch.133,§21.In addition, state legislative approval of the financing of the project is required.See ALASKA STAT.§§44.83.360 (1977) 851025 2 -I -j [ -I (B)ALASKA STAT.§§46.l5.030-46.l5.l85 (1982)("Appropria- tion and Use of Water");ALASKA ADMIN.CODE tit.11, §§93.040-93.l40 (Jan.1980)("Appropriation of Water"). These statutory provisions and regulations set forth the manner in which a right to appropriate water in Alaska may be acquired. They require that application for a permit to appropriate be made to the Department of Natural Resources.See ALASKA STAT. §46.l5.040 (1982);ALASKA ADMIN.CODE tit:-Tl,§93.040 (Apr. 1985).They aiso list certain criteria which must be considered when evaluating the application.See ALASKA STAT.§46.l5.080 (1982);ALASKA ADMIN.CODE title 1~§93.l20 (Apr.1985).In addition,the cited statute and regulations specify under what conditions one who has been granted a permit to appropriate shall be granted a certificate of appropriation. (C)ALASKA ADMIN.CODE tit.11,§§93.l50-93.200.l85 (Jan. 1980)("Dam Safety and Construction"). These regulations (also promulgated pursuant to ALASKA STAT. §46.l5.030-46.l5.l85 (1982),discussed in (B)above)require a "certificate of approval"to be obtained from the Department of Natural Resources prior to construction of dams as large as those proposed for the Susitna Project.Approval is based on informa- tion contained in drawings and design data submitted with the application for the certificate. (D)ALASKA STAT.§16.05.870 (1983)("Protection of Fish and Game")• This section required that ~ny person or governmental agency intending to "use,divert-••or change the natural flow or bed"of a river,lake or stream,such as the Susitna River,which has been designed as important to the spawning,rearing or migration of anadromous fish (1)notify the Department of that intent and (2) await its approval of the construction. (E)ALASKA STAT.§§16.1O.0l0-l6.l0.020 (1983)("Interference With Salmon Spawning Streams and Waters","Grounds for Permit or License"). These sections essentially require that any person who will erect a dam which may affect salmon spawning streams or waters first apply for and obtain a permit or license from the Department of Environmental Conservation.One purpose for which a permit or license may be granted is the development of power.As a condi- tion for such a permit adequate fishways may be required. 851025 3 ~I \ I =i -j I I I -I ) I -I I I I -I (F)ALASKA STAT.§16.05.840 (1983)("Fishway Required"). The Commissioner of the Department of Fish and Game may require that a fishway be provided for a dam built across a stream fre- quented by salmon or other fish.In the event that a fishway is considered necessary,plans and specifications must be submitted for approval. (G)ALASKA ADMIN.CODE tit.18,§§15.l30-l5.l80 (Jan.1978) ("Certification"). Under Federal law,an applicant for a Federal license to construct or operate a facility must make application to obtain from the State a certification of compliance with the Federal Water Pollution Control Act.33 U.S.C.§134l (1977).Issuance of such a certificate is governed by ALASKA ADMIN.·.CODE tit.18, §§15.l30-l5.l80.The pro~edures governing that certification process are set forth in these sections of the Code. (H)ALASKA STAT.§38.05.020-38.05.330 (1984)("Alaska Lands Act II)• These sections of the Alaska Statutes provide the methods by which the Alaska Power Authority may obtain use of state lands.The Department of Natural Resources may lease,sell or otherwise dispose of state land to a state or political subdivision for less than its appraised value if such action is found by the Department to be fair and proper and in the best interests of the public. ALASKA STAT.§38.05.810 (1984).The Department may issue permits, rights-of-way or easements on state land for roads and electric transmission and distribution lines.ALASKA STAT.§38.05.810 (1984).Prior to disposing of state land which is adjacent to a body of water or a waterway,the Department must deteDmine whether the body of water·or waterway is navigable or public water or neither.If it is navigable or public water,the Department may provide for easements or rights-of-way.ALASKA STAT.§38.05.l27 (a)(1984). (I)ALASKA STAT.§§46.40.030-46.40.040;§§46.40.090- 46.40.100 (1982)("Development of Alaska Coastal Management Program");ALASKA ADMIN.CODE tit.6, §50.011-50.190 (Apr.1984)("Project Consistency with Alaska Coastal Management Program"). These sections require that the Alaska Coastal Policy Council, state agencies,and municipalities administer the resources within a coastal area in a manner consistent with the applicable district coastal management plan.The Susitna Project is located within a designated coastal resource district. 851025 4 l I I I ] -I I I -j I I I -] '-I -I 1 (J)ALASKA ADMIN.CODE tit.18,§§15,50 (Jan.1984)("Air Quali ty Con tro 111)• These regulations provide for permit applications for various facilities as described in ALASKA ADMIN.CODE tit.18,§50.300(a). Applications for permits from the Department of Environmental Conservation must include information set forth in ALASKA ADMIN. CODE tit.18,§§50.300(b),(c),(d),and (e). (K)ALASKA ADMIN.CODE tit.18,§.72 (Jan.1983)("Waste Water Disposal"). These regulations provide for permits issued by the Department of Environmental Conservation for the disposal of domestic wastewater into or onto waters or lands in Alaska,as well as general permits for activities producing wastewater.ALASKA ADMIN.CODE tit.18, §§72.0l5 and 72.920. 5.(ii)The steps which the applicant has taken,or plans to take,to comply with each of the laws cited above are: (A)ALASKA STAT.§§44.83.0l0-44.83.425 (1977),1982 Supp.). The Alaska Power Authority has sought legislative approval of its preliminary report on the Susitna Project. (B)ALASKA STAT.§§46.l5.030-46.l5.l85 (1982);ALASKA ADMIN. CODE tit.11,§§93.040-93.l40 (Apr.1985). An investigation of existing water rights has been completed ln connection with the permit required by the cited statute and regulations.The results indicate that the project would have a materially adverse impact on existing water rights.In addition, the Alaska Power Authority has applied for a permit to appropriate water for the Susitna Project.In addition,the Alaska Power Authority has applied for a permit to appropriate water for the Susitna Project from the Department of Natural Resources,and has been in cooperation with the Department in providing the necessary information to establish that such appropriation is in the public interest. (C)ALASKA ADMIN.CODE tit.11,§§93.l50-93.200 (Apr. 1985)• The required drawings and design data are contained in Exhibits B, F,and G of this Initial Statement.The Alaska Power Authority has applied for a certificate of approval. 851025 5 ~ I ! =1 -1 l \ I \ 1. l I -I I I -I ! I I ~I -I l (D)ALASKA STAT.§16.05.870 (1983). The Alaska Power Authority has notified the Department of Fish and Game of its intent to construct the project on the Susitna River. (E)ALASKA STAT.§§16.l0.0l0-l6.l0.020 (1977). The Alaska Power Authority has apprised the appropriate Depart- ments of the Susitna Project and requested a ruling of its permitting requirements pursuant to these sections.Authorization pursuant to ALASKA STAT.§16.l4.0l0 has been received from the Department of Environmental Conservation. (F)ALASKA STAT.§16.05.840 (1977). The Alaska Power Authority has notified the Department of Fish and Game of the Susitna Project. (G)ALASKA ADMIN.CODE tit.18,§§15.l30-l5.l80 (Jan. 1978). The Alaska Power Authority has notified the Department of Environ- mental Conservation that it will seek a certificate of compliance with the Federal Water Pollution Control Act.Under Alaska regulations,application for such a certificate is made by serving on the Department a copy of the Federal license application con- temporaneously with submission of the application to the Federal agency.ALASKA ADMIN.CODE tit.18,§15.l80(c).The Alaska Power Authority has complied with this requirement. (H)ALASKA STAT.§38.05.020-38.05.030 (1982 Supp.). The Alaska Power Authority has requested a right-of-way for transmission lines from the Department of Natural Resources. Rights-of-way may be requested for an access road and a railroad spur.If any state land acquired for the Susitna Project is adjacent to public or navigable waters,the Department of Natural Resources will determine whether easements or rights-of-way shall be provided. (I)ALASKA STAT.§§46.40.030-46.40.040;§§46.40.040- 46.40.100 (1982);ALASKA ADMIN.CODE tit.6 §§50.010-50.190 (Apr.1984). The Susitna Project will be reviewed for consistency with the coastal management plan of the borough of Matanuska.This review process is initiated when federal permit-granting agencies forward copies of the Susitna application to the the Govenor of the State of Alaska (Office of Management and Budget)as part of the federal permit process. 851025 6 (J)ALASKA ADMIN.CODE tit.18,§§15,50 (Jan.1984). The Alaska Power Authority has requested a permit from the Department of Environmental Conservation,and has submitted a proposed air quality control program along with supplemental information including a proposed monitoring program. (K)ALASKA ADMIN.CODE tit.18,§72 (Jan.1983). The Alaska Power Authority has requested a wastewater disposal permit from the Department of Environmental Conservation. IN WITNESS WHEREOF,the applicant,Alaska Power Authority,has caused its name to be signed below by Robert B.Heath,its Executive Director,and its seal to be affixed hereto by ,its ,this day of -------~_____,1985. ALASKA POWER AUTHORITY By ---,,.....--,-_ Robert B.Heath Executive Director (SEAL) 851025 7 -I \ I =1 -I I I I I I -I ! ! l I j ALASKA STATUTES "",I Chapter 83.Alaska Power Authority. Article 1.Creation and Organization (§§44.83.010 -44.83.045) 2.Purpose and Powers (§§44.83.070 -44.83.092). 3.Financial Provisions (§§44.83.100 -44.83.160) 4.Power Cost Equalization Program (§§44.83.162 -44.83.165) 5.Power Project Fund (§44.83.170) 6.General Provisions (§§44.83.177 -44.83.240) .7.Susitna River Hydroelectric Project (§§44.83.300 -44.83.360) 8.Rural Electrification Revolving Loan Fund (§§44.83.361 -44.83.363) 9.Energy Program for Alaska (§§44.83.380 -44.83.425) Article 1.Creation and Organization. Section 10.Legislative finding and policy 20.Creation of authority 30.Membership of the authority Section 40.Officers;meetings;quorum 45.Qualifications,powers,and duties of officers and directors Sec.44.83.010.Legislative finding and policy.Ca)The legisla- ture finds,detennines and declares that 268 I Revi80r'.note..-Formerly AS 44.56.020.Renumbered in 1980. Revi80r'.note..-Formerly AS 44.56.010.Renumbered in 1980. ~ I l 1 \ §44.83.030STATEGoVERNMENT§44.83.020 Sec.44.83.020.Creation of authority.There is created the Alaska Power Authority.The authority is a public corporation of the state in the Department of Commerce and Economic Development but with separate and independent legal existence.(§1 ch 278 SLA 1976) (1)there exist numerous potential hydroelectric and fossil fuel gathering sites in the state; (2)the establishment of power projects at these sites is necessary to supply power at the lowest reasanable cost to the state's municipal electric,rural electric,cooperative electric,and private electric utilities,and regional electric authorities,and thereby to the con- sumers of the state,as well as to supply existing or future industrial needs; (3)the achievement of the goals of lowest reasonable consumer power costs and beneficial long-term economic growth and of estab- lishing,operating and developing power projects in the state will be accelerated and facilitated by the creation of an instrumentality of the state with powers to construct,acquire,finance,and operate power projects. (b)It is declared to be the policy of the state,in the interests of promoting the general welfare of all the people of the state,and public purposes,to reduce consumer power costs and otherwise to encourage the long-term economic growth of the state,including the development of its natural resources,through the establishment of power projects by creating the public.corporation with powers,duties and functions as provided in this chapter.(§1 ch 278 SLA 1976;am §1 ch 156 SLA 1978) Sec.44.83.030.Membership of the authority.The authority .shall consist of the following directors: (1)three public directors to be appointed by the governor and confirmed by the legislature;only one director may be appointed from each judicial district described in AS 22.10.010; (2)the director of the office of management and budget,or the director's designee within that office,and three commissioners ofprin- cipal executive departments appointed by the governor.(§1 ch 278 SLA 1976;am §2 ch 156 SLA 1978;am §2 ch 118 SLA 1981;am §25 ch 63 SLA 1983) 269 §44.83.040 ALASKA STATUTES §44.83.040 -I Revisor's notes.Formerly AS 44.56.030.Renumbered in 1980. Cross references.-For transitional provisions related to the authority's 1981 reorganization,see §15,ch.118,SLA 1981. Effect of amendments.-The 1981 amendlnent deleted the subsection desig-· nation (a)and repealed subsection (b) which read "The commissioners of commu- nity and regional affairs,natural resources,transportation and public facilities,and revenue shall have the rights and privileges of directors except for the right to vote and may not be considered for purposes of quorum or voting."The amendlnent also substituted "three pub- lie"for "four"preceding "directors," deleted "at large"preceding "to be appointed"and added "only one director may be appointed from each judicial dis- trict described in AS 22.10.010"in para- graph (l)and substituted "the director of the division of budget and management and three commissioners of principal executive departments appointed by the governor"for "the commissioner of com- merce and economic development"in para- graph (2). The 1983 amendment,in paragraph (2) substituted "office of management and budget,or the director's designee within that office,"for "division of budget and management." -I Sec.44.83.040.Officers;meetings;quorum.(a)The directors shall elect one of their number as chairman and may elect other officers they determine desirable.The powers of the authority are vested in the directors,and four directors of the authority constitute a quorum. Action may be taken and motions and resolutions adopted by the authority at a meeting by the affirmative vote of a majority of the directors.The directors of the authority serve without compensation, but they shall receive the same travel pay and per diem as provided by law for board members. (b)The board may meet and transact business by an electronic medium if (1)public notice of the time and locations where the meeting will be held by an electronic medium has been given in the same manner as if the meeting were held in a single location; (2)participants and members of the public in attendance can hear and have the same right to participate in the meeting as if the meeting were·conducted in person;and (3)copies of pertinent reference materials,statutes,regulations,and audio-visual materials are reasonably availablE!to participants and to the public. (c)A meeting by an electronic medium as provided in this section has the saIJ1e legal effect as a meeting in person. (d)A director of the authority may not vote on a resolution of the authority relating to a lease or contract to be entered into by the authority under this chapter if the director is a party to the lease or contract or has a direct ownership or equity int.erest in a firm,partner- ship,corporation,or association that is a party to the contract or lease. When abstaining from voting,the director must disclose the reason for the abstention.A director who is a member of an electric cooperative that is organized under or subject to the Electric and Telephone Coop- erative Act (AS 10.25)may vote on a resolution relating to a contract or lease to which that cooperative is a party.The director shall disclose 270 §44.83.045 STATE GOVERNMENT §44.83.050 the cooperative membership at the time of voting.A resolution of the authority that is approved by a majority of the directors present who are not barred from voting under this subsection is a valid action of the authority for all purposes.(§1 ch 278 SLA 1976;am §3 ch 156 SLA 1978;am §3 ch 118 SLA 1981;am §§1,2 ch 89 SLA 1983) Revisor's notes.-Formerly AS 44.56.040.Renumbered in 1980. Effect of amendments.-The 1981 amendment substituted "directors"for "director,"substituted "their number"for "the directors at large"and added "may elect"preceding "other officers"in the first sentence and substituted "four"for "three" preceding "directors"in the second sen- tence. The 1983 amendment substituted "a majority of the directors"for "at least three directors"at the end of the third sen- tence of subsection (a)and added subsec- tions (b)-(d). ~i \ Sec.44.83.045.Qualifications,powers,and duties of officers and directors.(a)The public directors shaH be residents and qualified voters of Alaska and shall comply with the requirements of AS 39.50.010 -39.50.200 (conflict of interests).The public directors shall serve overlapping four-year terms. (b)A vacancy in a directorship occurring other than by expiration of a term shall be filled in the same manner as the original appointment, but for the unexpired portion of the term only. (c)The authority shall employ an executive director who may,with the approval of the authority,employ additional staff as necessary.In addition to its staff of regular employees,the authority may contract for and engage the services of legal and bond counsel,consultants, experts,and financial and technical advisors the authority considers necessary for the purpose of conducting studies,investigations, hearings,or other proceedings.The board of directors shall establish the compensation of the executive director.The executive director of the authority is subject to the provisions of AS 39.25.010 -39.25.220. (§4 ch 156 SLA 1978;am §4 ch 118 SLA 1981) -I I Revisor's notes.-Formerly AS 44.56.045.Renumbered in 1980. Etlect of amendments.-The 1981 amendment added "public"preceding "directors"and substituted "shall"for "at large must"preceding "be residents"in the first sentence,added "public"preceding "directors,"deleted "at large"following "directors"and added "overlapping" preceding "four-year terms"in the second sentence and deleted the former third sen- tence which read "The four original directors at large have terms of one,two, three.and four years,respectively." Sec.44.83.050.Staff.[Repealed,§23ch 156 SLA 1978.1 Article 2.Purpose and Powers. Section 70.Purpose of the authority 80.Powers of the authority 90.Power contracts and the Alaska Public Utilities Commission Section 92.Authority for municipalities and utilities to enter into power sales contracts 271 §44.83.070 ALASKA STATUTES §44.83.080 Sec.44.83.070.Purpose of the authority.The purpose of the authority is to promote,develop and advance the general prosperity and economic welfare of the people of Alaska by providing a means of constructing,acquiring,financing and operating (1)power projects;and (2)facilities that recover and use waste energy.(§1 ch 278 SLA 1976;am §5 ch 156 SLA 1978;am §1 ch 133 SLA 1982) Revisor's notes.-Formerly AS 44.56.010.Renumbered in 1980. Effect of amendments.-The 1982 amendment substituted paragraphs (l) and (2)for "power production facilities lim- ited to fossil fuel,wind power,tidal, geothermal,hydroelectric,or solar energy production and waste energy conservation facilities." l Sec.44.83.080.Powers of the authority.In furtherance of its cor· porate purposes,the authority has the following powers in addition to its other powers: (1)to sue and be sued; (2)to have a seal and alter it at pleasure; (3)to make and alter bylaws for its organization and internal management; (4)to adopt regulatio~s governing the exercise of its corporate powers; (5)to acquire,whether by construction,purchase,gift or lease,and to improve,equip,operate,and maintain power projects; (6)to issue bonds to carry out any of its corporate purposes and powers,including the acquisition or construction of a project to be owned or leased,as lessor or lessee,by the authority,or by another person,or the acquisition of any interest in a project or any right to capacity of a project,the establishment or increase of reserves to secure or to pay the bonds or interest on them,and the paYment of all other costs or expenses of the authority incident to and necessary or convenient to carry out its corporate purposes and powers; (7)to sell,lease as lessor or lessee,exchange,donate,conveyor encumber in any manner by mortgage or by creation of any other security interest,real or personal property owned by it,or in which it has an interest,when,in the judgment of the authority,the action is in furtherance of its corporate purposes; (8)to accept gifts,grants or loans from,and enter into contracts or other transactions regarding them,with any person; (9)to deposit or invest its funds,subject to agreements with bondholders; (10)to enter into contracts with the United States or any person and, subject to the laws of the United States and subject to concurrence of the legislature,with a foreign country or its agencies,for the financing, construction,acquisition,operation and maintenance of all or any part of a power project,either inside or outside the state,and for the sale or 272, §44.83.080 STATE GOVERNMENT §44.83.080 J ) transmission of power from a project or any right to the capacity of it or for the security of any bonds of the authority issued or to be issued for the project; (11)to enter into contracts with any person and with the United States,and,subject to the laws of the United States and subject to the concurrence of the legislature,with a foreign country or its agencies for the purchase,sale,exchange,transmission,or use of power from a project,or any right to the capacity of it; (12)to apply to the appropriate agencies of the state,the United States and to a foreign country and any other proper agency for the permits,licenses,or approvals as may be necessary,and to construct, maintain and operate power projects in accordance with the licenses or permits,and to obtain,hold and use the licenses and permits in the same manner as any other person or operating unit; (13)to perform reconnaissance studies,feasibility studies,and engi- neering and design with respect to power projects; (14)to enter into contracts or agreements with respect to the exer- cise of any of its powers,and do all things necessary or convenient to carry out its corporate purposes and exercise the powers granted in this chapter; (15)to exercise the power of eminent domain in accordance with AS 09.55.240 -09.55.460; (16)to recommend to the legislature (A)the issuance of general obligation bonds of the state to finance the construction of a power project if theauthority first determines that the project cannot be financed by revenue bonds of the authority at reasonable rates of interest; (B)the pledge of the credit of the state to guarantee repayment of all or any portion of revenue bonds issued to assist in construction of power projects; (C)an appropriation from the general fund (i)for debt service on bonds or other project purposes;or (ii)to reduce the amount of debt financing for the project; (D)an appropriation to the power project fund for a power project; (E)[Repealed,§16 ch 161 SLA 1984.1 (F)development of a project under financing arrangements with other entities using leveraged leases or other financing methods; (G)an appropriation for a power project acquired or constructed under the energy program for Alaska (AS 44.83.380 -44.83.425).(§1 ch 278 SLA 1976;am §§6 -11 ch 156 SLA 1978;am §§16,17 ch 83 SLA 1980;am §5 ch 118 SLA 1981;am §16 ch 161 SLA 1984) Revisor's note..-Formerly AS 44.56.080.Renumbered in 1980. Effect of amendments.-The 1980 amendment inserted in the middle of para- graph (13),"feasibility studies,and engi- neering and design,"and added paragraph (16). The 1981 amendment added subpara- graph (G)of paragraph (16). The 1984 amendment repealed para- graph (16)(E). 273 274 Sec.44.83.090.Power contracts and the Alaska Public Utilities Commission.(a)The a~thority shall,in addition to the other methods which it may find advantageous,provide a method by which municipal electric,rural electric,cooperative electric,or private elec- tric utilities and regional electric authorities,or other persons autho- rized by law to engage in the distribution of electricity may secure a reasonable share of the power generated by a project,or any interest in a project,or for any right to the power and shall sell the power or cause the power to be sold at the lowest rel\!ionahle prices which cover the full cost of the electricity or services,including capital and operating costs,debt coverage as considered appropriate by the author- ity,'and other charges that may be authorized by AS 44.83.010 - 44.83.425.Except for a contract or lease entered into under AS 44.83.380 -44.83.425,a contract or lease for the sale,transmission and distribution of power generated by a project or any right to the capacity of it shall provide:, (1)for payment of all operating and maintenance expenses of a project and costs of renewals,replacements and improvements of it; (2)for interest on and amortization charges sufficient to retire bonds of the authority issued for the project and reserves foI:'them,plus a debt service coverage factor as may be determined by the authority to be necessary for the marketability of its bonds; (3)for monitoring of the project by the authority or its agents; (4)for full and complete disclosure to the authority of all factors of costs in the transmission and distribution of power,so that rates to any persons may be fixed initially in the contract or lease and may be adjusted from time to time on the basis of true cost data; (5)for periodic revisions of the service and rates to persons on the basis of accurate cost data obtained by tb.e accounting methods and systems approved by the directors and in furtherance and effectuation of the policy declared in AS 44.83.010 -44.83.425; (6)for t~e cancellation and termination of a contract or lease upon violation of its terms by any person; (7)for security for performance as the authority may consider prac- ticable and advisable,including provisions assuring the continuance of the distribution and transmission of power generated by a project and the use of its facilities for these purposes;and (8)other terms not inconsistent with the provisions and policy of this chapter as the authority may consider advisable. (b)The authority is not subject to the jurisdiction of the Alaska Public Utilities Commission.Nothing in AS 44.83.010 -44.83.425 grants the authority any jurisdiction over the services or rates of any public utility or diminishes or otherwise alters the jurisdiction of the Alaska Public Utilities Commission with respect to any public utility, including any right the commission may have to review and approve or disapprove contracts for the purchase of electricity by a public util- l I -I I -I l I -I I §44.83.090 ALASKA STATUTES §44.83.090 §44.83.092 STATE GOVERNMENT §44.83.100 ity.(§1 ch 278 SLA 1976;am §12 ch 156 SLA 1978;am §6 ch 118 SLA 1981) Revisor's notes.-Formerly AS 44.56.090.Renumbered in 1980. Effect of amendments.-The 1981 amendment substituted "except for a contract or lease entered into under AS 44.83.380 -44.83.425,a"for "a" preceding "contract"and added "or lease" preceding "for the sale"in the second sen- tence of subsection (a)and added "or lease" following "contract"in paragraphs (4)and (6)of subsection (a). Sec.44.83.092.Authority for municipalities and utilities to enter into power sales contracts.The authority and any munic- ipality or public or private entity operating an electric utility,or a municipality or private entity and another municipality or private entity,may enter into a contract providing for or relating to the sale of electric power by the authority to the municipality or entity,or by the municipality or entity to another municipality or entity.The contract may provide (1)that the amounts payable under the contract are operating expenses of the utility and are valid and binding obligations of the municipality or other entity payable from the gross revenues of the utility;. (2)for one or more appropriations of the amounts payable under the contra~t; (3)for the municipality or other entity to assume the obligations of another contracting party in the event of a default by that party; ~4)that after completion of a project the municipality or other entity is obligated to make payments notwithstanding a suspension or reduc- tion in the amount of the power supplied by the project;or (5)that payments under the contract are not subject to reduction by offset or otherwise.(§3 ch 89 SLA 1983) Article 3.Financial Provisions. Section 100.Bonds of the authority 105.Bonds for power projects under the energy program for Alaska 110.Trust indentures and trust agree- ments 120.Validity of pledge Section 130.Nonliability on bonds 140.Pledge of the state 150.Tax exemption 160.Bonds legal investments for fi- duciaries Sec.44.83.100.Bonds of the authority.(a)The authority may borrow money and may issue bonds,including but not limited to bonds on which the principal and interest are payable (1)exclusively from the income and receipts or other money derived from the project financed with the proceeds of the bonds;(2)exclusively from the income and 275 Revisor'lI·notell.-Formerly AS 44.56.100.Renumbered in-1980. Sec.44.83.105.Bonds for power projects under the energy program for Alaska.The authority may borrow money and issue its bonds for the acquisition or construction of power projects to be acquired or constructed under the energy program for Alaska.The principal of and interest on the bonds are payable from money derived from the sale of wholesale power from power projects financed under AS 44.83.380 ~44.83.425 from the power development fund or from a source referred to in AS 44.83.100 as the authority determines.The bonds may be issued if (1)appt:Opriations to the power development fund for the power project are insufficient to cover the cost of acquiring or constructing the power project;and (2)the authority determines that the amount ofinterest the author- ity will pay on its bonds is not more than alternative costs of securing money from other sources,except for the general fund,to pay for the .acquisition or construction of the power project.(§7 ch 118 SLA 1981; am §4 ch 89 SLA 1983) receipts or other money derived from designated projects whether or not they are financed in whole or in part with the proceeds of the bonds; (3)from its income and receipts or other assets generally,or a desig- nated part or parts of them;or (4)from one or more revenue-producing contracts including a contract providing for the security of the bonds made by the authority with any person.The authority may issue bonds to pay,fund or refund the principal of,or interest or redemption pre- miums on,bonds issued by it,whether or not the bonds or interest to be funded or refunded have become due. (b)Bonds shall be authorized by resolution of the authority,and shall be dated and shall mature as the resolution may provide,except that no bond may mature more than 50 years from the date of its issue. Bonds shall bear interest at the rates,be in the denominations,be in the form,either coupon or registered,carry the registration privileges, be executed in the manner,be payable in the medium of payment,at the places,and be subject to the terms of redemption which the resolu- tion or a subsequent resolution may provide. (c)All bonds,regardless of form or character,shall be negotiable instruments for all the purposes of the Uniform Commercial Code. (d)All bonds may be sold at public or private sale in the manner,for the price or prices,and at the time or times which the authority may determine.(§1 ch 278 SLA 1976) 1 I I ) ) 1 ) -I §44.83.105 ALASKA STATUTES §44.83.105 Effect 01 amendment!.-The 1983 amendment,divided the section into three sentences;in the first sentence,substi· tuted "may borrow"for "shall borrow," deleted "shall"preceding "issue its bonds," and substituted the language beginning 276 STATE GOVERNMENT§44.83.110 "for the acquisition or construction"for "on which"at the end;in the second sentence, inserted "of'following "principal"and added "on the bonds"following "and inter- est"and added the language beginning "or from a source"to the end;and in the third §44.83.110 sentence,added "The bonds may be issued"at the .beginning,added "the authority determines that"at the beginning of paragraph (2),and inserted "from other sources,except for the general fund"in paragraph (2). Sec.44.83.110.Trust indentures and trust agreements.(a)In the discretion of the authority,an issue of bonds may be secured by a trust indenture or trust agreement between the authority and a corpo- rate trustee (which may be a trust company,bank,or national banking assoeiation,with corporate trust powers,located inside or outside the state)or by a secured loan agreement or other instrument or under a resolution giving powers to a corporate trustee by means of which the authority may (1)make and enter into any and all the covenants and agreements with the trustee or the holders of the bonds that the authority may determine to be necessary or desirable,including,without limitation, covenants,provisions,limitations and agreements as to (A)the application,investment,deposit,use and disposition of the proceeds of bonds of the authority or of money or other property of the authority or in which it has an interest; (B)the fIXing and collection of rentals,charges,fees or other con- sideration for,and the other terms to be incorporated in,contracts with respect to a project·or to generated power; (C)the assignment by the authority of its rights in contracts with respect to a project or to generated power or in a mortgage or other security interest created with respect to a project or generated power to a trustee for the benefit of bondholders; (D)the terms and conditions upon which additional bonds of the authority may be issued; (E)the :vesting in a trustee of rights,powers,duties,funds or prop- erty in trust for the benefit of bondholders,including,without limi- tation,the right to enforce payment,performance,and all other rights of the authority or of the bondholders,under.a lease,power of contract, contract of sale,mortgage,security agreement,or trust agreement with respect to a project by injunction or other proceeding or by taking possession o£by agent or otherwise and operating a project and collecting rents or other consideration and applying the same in accor- dance with the trust agreement; (2)pledge,mortgage or assign money,leases,agreements,property or other rights or assets of the authority either presently in hand or to be received in the future,or both;and (3)provide for any other matters of like or different character which in any way affect the security or protection of the bonds. (b)Notwithstanding any other provisions of this chapter,the trust indenture,trust agreement,secured loan agreement,or other instrument or the resolution constituting a contract with bondholders 277 ~I shall contain a covenant by the authority that it will at all times maintain rates,fees or charges sufficient to pay,and that a contract entered into by the authority for the sale,transmission or distribution of power shall contain rates,fees or charges sufficient to pay the costs of operation and maintenance of the project,the principal of and inter- est on bonds issued under the trust agreement as the same severally become due and payable,to provide for debt service coverage as con- sidered necessary by the authority for the marketing of its bonds and to provide for renewals,replacements and improvements of the project, and to maintain reserves required by the terms of the trust agreement. This .subsection does not require a covenant that varies from a covenant entered into in accordance with the provisions of AS 44.83.380 -44.83.425. (c)For the purpose of securing anyone or more issues of its bonds, the authority may establish one or more special funds,called "capital reserve funds",and shall pay into those capital reserve funds the pro- ceeds of the sale of its bonds and any other money that may be made available to the authority for the purposes of those funds from any other source.The funds shall be established only if the authority deter- mines that the establishment would enhance the marketability of the bonds.All money held in a capital reserve fund,except as provided in this section,shall be used as required,solely for (1)the payment of the principal of,and interest on,bonds or of the sinking fund payments with respect to those bonds,(2)the purchase or redemption of bonds, or (3)the payment of a redemption premium required to be paid when those bonds are redeemed before maturity;however,money in a fund may not be withdrawn from it at any time in an amount that would reduce the amount of that fund to less than the capital reserve require- ment set out in (2)of this subsection,except for the purpose of making, with respect to those bonds,payment,when due,of principal,interest, redemption premiums and the sinking fund payments for the payment of which other money of the authority is not available.Income or interest earned by,or increment to,a capital reserve fund,due to the investment of the fund or any other amounts in it,may be transferred by the authority to other funds or accounts of the authority to the extent that the transfer does not reduce the amount of the capital reserve fund below the capital reserve fund requirement.. (d)If the authority decides to issue bonds secured by such a capital reserve fund,the bonds may not be issued if the amount in the capital reserve fund is less than such an amount as may be established by resolution of the authority (called the "capital reserve fund require- ment"),unless the authority,at the time of issuance of the obligations, deposits in the capital reserve fund from the proceeds of the obligations to be issued or from other sources,an amount which,together with the amount then in the fund,will not be less than the capital reserve fund requirement. l 1 I· I ~ I §44.83.110 ALASKA STATUTES §44.83.110 278 §44.83.110 STATE GOVERNMENT §44.83.110 (e)In computing the amount of a capital reserve fund for the purpose of this section,securities in which all or a portion of the funds are invested shall be valued by some reasonable method established by the authority by resolution.Valuation on a particular date shall include ,the amount of any interest earned or accnted to that date. (f)The chairman of the authority shall annually,no later than Jan- uary 2,make and deliver to the governor and the legislature a certif- icate stating the sum,if any,required to restore any capital reserve fund to the capital reserve fund requirement.The legislature may aJlpr_opriate such a sum,and all sums appropriated during the then current fiscal year by the legislature for such restoration shall be deposited by the authority in the proper capital reserve fund.Nothing in this section creates a debt or liability of the state. (g)When the authority has created and established a capital reserve fund,the commissioner of revenue may lend surplus money in the general fund to the authority for deposit in a capital reserve fund in an amount equal'to the capital reserve fund requirement.The loans shall be made on such terms and conditions as may be agreed upon by the commissioner of revenue and the authority,including without limi- tation terms and conditions providing that the loans need not be repaid until the obligations of the authority secured and to be secured by the capital reserve fund are no longer outst{lI1ding. (h)If the authority decides to covenant to issue or to issue bonds secured by a capital reserve fund,tbe bonds may not be issued until 10 days after the authority has mailed notification to the State Bond Committee and the Legislative Budget and Audit Committee by certified mail of its intention to establish a capital reserve fund to secure the bond issue.The notification shall include the amount of the capital reserve fund to be established,the amount of bonds proposed to be issued,and the total cost of the project for which the bonds are to be issued.The notification shall be accompanied by an estimate by the authority of the need to withdraw money from the capital reserve fund during the term of the bond issue,the amount that it may be necessary to withdraw,and th~time at which withdrawals are estimated to be needed.The authority shall annually prepare a revised estimate,con- sidering the same factors,and a statement of all withdrawals that have occurred from the date of issuance of the bonds to the end of the calen- dar year.The revised estimate and statement shall be submitted to the State Bond Committee and the Legislative Budget and Audit Commit- tee by January 30 of the succeeding year.(§1 ch 278 SLA 1976;am §§13,14 ch 156 SLA 1978;am §2 ch 133 SLA 1982;am §5 ch 89 SLA 1983) I ) 1 Revisor's notes.-Fonnerly AS 44.56.110.Renumbered in 1980. Effect of amendments.-The 1982 amendment added subsection (h). The 1983 amendment,in subsection (b), substituted the language beginning "the trust indenture.trust agreement"and ending "constituting a contract with 279 §44.83.120 ALASKA STATUTES §44.83.140 Sec.44.83.120.Validity of pledge.It is the intention of the leg- islature that a pledge made in respect of bonds is considered perfected and is valid and binding from the time the pledge is made;that the money or property so pledged and thereafter received by the authority shall immediately be subject to the lien of the pledge without physical delivery or further act;and that the lien of the pledge shall be valid and binding as against all parties having claims of any kind in tort, contract or otherwise against the authority irrespective of whether the parties have notice.Neither the resolution,trust agreement nor any other instrument by which a pledge is created need be recorded or filed under the provisions of the Uniform Commercial Code to be perfected or to be valid,binding or effective against the parties.(§1 ch 278 SLA 1976;am §6 ch 89 SLA 1983) bondholders"for "the trust agreement" near the beginning of the first sentence and added the second sentence. Revisor's notes.-Formerly AS 44.56.120.Renumbered in 1980. Effect of amendments.-The 1983 amendment,substituted "is considered perfected and is valid"for "shall be valid" near the beginning of the first sentence and inserted "perfected or to be"in the sec- ond sentence. l ) Sec.44.83.130.Nonliability on bonds.(a)Neither the members of the authority nor a person executing the bonds is liable personally on the bonds or is subject to personal liability or accountability by reason of the issuance of the bonds. (b)The bonds issued by the authority do not constitute an indebted- ness or other liability of the state or of a political subdivision of the state,except the authority,but shall be payable solely from the income and receipts or other funds or property of the authority.The authority may not pledge the faith or credit of the state or of a political subdi- vision of the state,except the authority,to the payment ofa bond and the issuance of a bond by the authority does not directly or indirectly or contingently obligate the state or a political subdivision of the state to apply money from,or levy or pledge any form of taxation whatever to the payment of the bond.(§1 ch 278 SLA 1976) Revisor's notes.-Formerly AS 44.56.130.Renumbered in 1980. Sec.44.83.140.Pledge of the state.The state pledges to and agrees with the holders of bonds issued under this chapter and with the federal agency which loans or contributes funds in respect to a project, that the state will not limit or alter the rights and powers vested in the authority by this chapter to fulfill the terms of a contract made by the authority with the holders or federal agency,or in any way impair the rights and remedies of the holders until the bonds,together with the 280 §44.83.150 STATE GOVERNMENT §44.83.160 interest on them with interest on unpaid installments of interest,and all costs and expenses in connection with an action or proceeding by or on behalf of the holders,are fully met and discharged.The authority is authorized to include this pledge and agreement of the state,insofar as it refers to holders of bonds of the authority,in a contract with the holders,and insofar as it relates to a federal agency,in a contract with the federal agency.(§1 ch 278 SLA 1976) Revisor's DoteS.-Formerly AS 44.56.140.Renumbered in 1980. Sec.44.83.150.Tax exemption.All property of the authority is public property devoted to an essential public and governmental function and purpose and is exempt from all taxes of the state or a political subdivision of the state;however,the authority may make payments in place of taxes in amounts equal to the real and personal property taxes which would be assessed on its real and personal prop- erty by each political subdivision in which its property is located to the same extent as ifthat property were private property and the authority were a non-public corporation.All bonds issued under this chapter are issued by a body corporate and public of this state and for an essential public and governmental purpose and the bonds and the interest and income on and from the bonds and all income of the authority are exempt from taxation except for transfer,inheritance and estate taxes. (§1 ch 278 SLA 1976;am §15 ch 156 SLA 1978) Revisor's DoteS.-Formerly AS 44.56.150.Renumbered in 1980. Sec.44.83.160.Bonds legal investments for fiduciaries.The bonds of the authority are securities in which all public officers and bodies of the state and all municipalities and municipal subdivisions, all insurance companies and associations and other persons carrying on any insurance business,all banks,bankers,trust companies, savings banks,savings associations,including savings and loan asso- ciations and building and loan associations,investment companies and other persons carrying on a banking business,all administrators, guardians,executors,trustees and other fiduciaries,and all other persons whatsoever who are now or may hereafter be authorized to invest in bonds or other obligations of the state,may properly and legally invest funds including capital in their control or belonging to them.Notwithstanding any other provisions of law,the bonds of the authority are also securities which may be deposited with and may be received by all public officers and bodies of this state and all munic- ipalities and minicipal subdivisions for any purpose for which the deposit of bonds or other obligations of the state is now or may hereafter be authorized.(§1 ch 278 SLA 1976) 281 ) l I j J I §44.83.162 ALASKA STATUTES §44.83.162 Revisor's notes.Formerly AS 44.56.160.Renumbered in 1980. Article 4.Power Cost Equalization Program. Section not regulated by Public Utilities Commission 165.Continuing appropriation for power cost equalization Section 162.Power cost equalization 163.Adjustments to power cost equalization 164.Equalization assistance to utilities l I -) Sec.44.83.162.Power cost equalization.(a)The power cost equalization fund is established as a separate fund for the purpose of equalizing power cost per kilowatt-hour statewide at a cost close or equal to the mean of the cost per kilowatt-hour in Anchorage, Fairbanks,and Juneau by paying money from the fund to eligible electric utilities in the state.The fund shall be administered by the authority as a fund distinct from the other funds of the authority.The fund is composed of money appropriated for the purpose of providing power cost equalization to eligible electric utilities. (b)The costs used to calculate the amount of power cost equalization for all electric utilities eligible under this section include all allowable costs,except return on equity,used by the commission to determine the revenue requirement for electric utilities subject to rate regulation under AS '42.05.The costs used in determining the power cost equalization per kilowatt-hour shall exclude any other type of assis- tance that reduces the customer's costs of power on a kilowatt-hour basis and that is provided to the electric utility within 60 days before the commission determines the power cost equalization per kilo- watt-hour of the electric utility. (c)An eligible electric utility is entitled to receive power cost equalization . (1)for sales of power to local community facilities,calculated in the aggregate for each community served b.y the electric utility,for actual consumption of not more than 70 kilowatt-hours per month for each resident of the community;and (2)for actual consumption of not more than 750 kilowatt-hours per month sold to each customer in all classes served by the electric utility except to customers of the utility under (1)of this subsection. (d)The amount of power cost equalization provided per kilo- watt-hour under (c)of this section may not exceed 95 percent of the power costs,or the average rate per eligible kilowatt-hour sold, whichever is less,as determined by the commission.However, (1)during the state fiscal year that begins July 1,1984 the power costs for which power cost equalization may be paid to an electric utility are limited to minimum power costs of more than 8.5 cents per kilowatt-hour and less than 52.5 cents per kilowatt-hour; 282 (2)during each following state fiscal year,the power costs for which power cost equalization may be paid to an electric utility shall be adjusted by the commission,considering the rate of change in fuel cost and power demand;and (3)the power cost equalization per kilowatt-hour may be determined for a utility without historical kilowatt-hour sales data by using kilo- watt hours generated. (e)An electric utility whose customers receive power cost equalization under this section shall set out in its tariff the rates withput the power cost equalization and the amount of power cost equalization per kilowatt-hour sold.The rate charged to the customer shall be the difference between the two amounts.Power cost equalization paid under this section shall be used to reduce the cost of all power sold to local community facilities,in the aggregate,to the extent of 70 kilowatt-hours per month per resident of the community, and to reduce the cost of the first 750 kil()watt-hours per customer per month for all other classes served by the electric utility. (f)The power cost equalization program shall be administered by the authority based on a determination by the commission under (b)and (d}of this section of power cost equalization per kilowatt-hour for each eligible electric utility.. (g)An eligible electric utility may not be denied power cost equalization because complete cost information is not available.An eligible ele.ctric utility that is exempt from rate regulation under AS 42.05 shall be assisted by the commission to provide the cost informa- tion the commission considers necessary to comply with the require- ments of this section.Only power costs that are supportable may be considered in calculating power cost equalization.Each electric utility is responsible for keeping records that provide the information neces- sary to comply with the requirements of this section including,but not limited to,records of monthly kilowatt-hour sales or generation, monthly fuel balances,fuel purchases,and monthly utility fuel consumption. (h)For each eligible electric utility,the determination of the cost of fuel by the commission shall be in accordance with the procedure for approving fu~l cost rate adjustments of electric utilities subject to rate regulation under AS 42.05.. (i)Each electric utility receiving power cost equalization approved by the commission shall (1)report monthly to the authority within the time and in the form the authority requires;and (2)use operational equipment designed to meter individual utility customer power consumption and to determine and record the utility's overall fuel consumption. (j)The authority shall review the report required under (i)(l)of this section and may submit the report to the commission for additional §44.83.162 STATE GOVERNMENT §44.83.162 -1 I 283 §44.83.162 ALASKA STATUTES §44.83.162 -1 I I \ review before payment.After review and approval of the report by the authority,the authority shall,subject to appropriation,pay to each eligible electric utility an amount equal to the power cost equalization per kilowatt-hour determined by the commission under (b)and (d)of this section,multiplied by the number of kilowatt-hours eligible for power cost equalization that were sold during the preceding month to all customers of the utility in accordance with (c)of this section. Payment shall be made by the authority within 30 days after receipt from the utility of the report required under (i)of this section.However, if there is a dispute between the authority and the utility relating to the payment,the authority shall submit the report to the commission for review within 30 days after its receipt by the authority.When a report is submitted to the commission for review under this section, payment shall be made by the authority within 30 days after submission,based on a commission determination.If appropriations are insufficient for payment in full,the amount paid to each electric utility is reduced on a pro rata basis. (k)If an electric utility receives power cost equalization under this section,the utility shall either (1)give the following notice to its electric service·customers eligible under this program for each period for which the payment is received: NOTICE TO CUSTOMER For the current billing period the utility will be paid under the State of Alaska's power cost equalization program (AS 44.83.162)to assist the utility and its customers in reducing the high cost of generation of electric energy. Your total electrical service cost $.. . . . . . Less state equalization $.. . . . . . Your charge $ ;or (2)give to its electric service customers a notice approved by the authority,which notice provides electric service customers the same information provided by the notice in (1)of this subsection. (/)In order to qualify for power cost equalization,each electric util- ity must make every reasonable effort to minimize administrative, operating,and overhead costs,including using the best available technology consistent with sound utility management practices.In reviewing applications for power cost equalization,the commission has the authority to require the elimination of duplicative or otherwise unnecessary operating expenses.Each eligible electric utility shall cooperate with appropriate state agencies to implement cost-effective energy conservation measures,and to plan for and implement feasible alternatives to diesel generation. (m)For purposes of (c)of this section,the number of residents of the community equals the number of residents .of the community deter- 284 §44.83.162 STATE GOVERNMENT §44.83.162 mined by the Department of Community and Regional Affairs in accor· dance with AS 29.88.015. (n)If the authority receives a petition requesting power cost equalization,signed by at least 25 percent of the customers of an elec- tric utility that is subject to rate regulation under AS 42.05 and that has not applied for power cost equalization under this section,the authority shall require the utility to submit a power cost equalization application.Upon a determination of eligibility for power cost equalization,the utility,as a part ofits service,shall receive power cost equalization and pass power cost equalization benefits to its customers in accordance with this section. (0)In this section (1)"commission"means the Alaska Public Utilities Commission; (2)"community facility"means a water and sewer facility,public outdoor lighting,charitable educational facility,or community build- ing whose operations are not paid for by the state,the federal govern- ment,or private commercial interests; (3)"eligible electric utility"or "electric utility"means each corpora- tion (whether public,cooperative,or otherwise),company,individual, or association of individuals,their lessees,trustees,or receivers appointed by a court,that (A)owns,operates,manages,or controls a plant or system for the furnishing,by generation,transmission or distribution,of electric ser- vice to the public for compensation; (B)during calendar year 1983 had a residential consumption level of power eligible for power cost equalization under this chapter of less than 7,500 megawatt hours or had a residential consumption level of power eligible for power cost equalization under this chapter of less than 15,000 megawatt hours if the utility served two or more munic- ipalities or unincorporated communities;and (C)during calendar year 1984 used diesel-fired generators to pro- duce more than 75 percent of the electrical consumption of the utility; an electric utility that is a subsidiary ofanother electric utility is an "eligible electric utility"if the operations of the subsidiary,considered separately,meet the eligibility requirements of this section;if an elec- tric utility did not receive power cost assistance in 1983 but is otherwise eligible for power cost equalization under this section,the utility is an "eligible electric utility"; (4)"energy conservation measures"include weatherization and other insulating methods,utilization of waste heat,appropriate sizing of new generating equipment,and other programs of the state or federal government intended and available for the purpose of energy conservation; (5)"feasible energy projects"include.projects that are selected after a field reconnaissance study under AS 44.83.177 and after completion of a feasibility study according to the criteria in AS 44.83.181 to deter- mine cost benefit in comparison to existing power generating methods and other alternatives considered in reconnaissance studies; 285 §44.83.163 ALASKA STATUTES §44.83.163 (6)"fund"means the power cost equalization fund established under (a)of this section; (7)"power costs"means costs used in determining power cost equalization in accordance with (b)and (d)of this section.(§42 ch 83 SLA 1980;am §8 ch 118 SLA 1981;am §3 ch 79 SLA 1983;am §1 ch 133 SLA 1984) Revisor's notes.-Fonnerly AS 44.56.162.Renumbered in 1980. Cross references.-For transitional provisions relating to the 1981 amend- ments,see §16,ch.118,SLA 198!. Effect of amendments.-The 1981 amendment rewrote this section. The 1983 amendment,in subsection (1), deleted "including but not limited to the Alaska Public Utilities Commission,the Alaska Power Authority,the Alaska Energy Center,and the division of energy and power development in the Department of Commerce and Economic Development" following "appropriate state agencies"in the last sentence. The 1984 amendment rewrote this sec- tion. Sec.44.83.~63.Adjustments to power cost equalization.(a)The power cost equalization per kilowatt-hour determined under AS 44.83.162 payable to an electric utility that is subject to rate regulation under AS 42.05 may be adjusted by the commission if (1)an increase or decrease in the electric utility's cost of fuel has resulted in the approval of a fuel cost rate adjustment by the commis- sion; (2)a permanent or interim rate increase or decrease has been approved by the commission,thereby establishing a higher or lower power cost; (3)an adjustment is required after the authority has discovered discrepancies in its review of monthly data submitted by the electric utility;or (4)the authority determines that appropriations are insufficient to finance full payments to eligible electric utilities. (b)An electric utility that is eligible to receive power cost equalization under this section and that receives power cost equalization per kilowatt-hour approved by the commission shall report monthly to the authority within the time and in -the form the authority·requires.An electric utility shall report (1)the power cost equalization per kilowatt-hour approved by the commission; (2)the total kilowatt-hours sold to each class of customer during the preceding month; (3)the total kilowatt-hours eligible for power cost equalization under this section sold to each class of customer during the preceding month; (4)the total kilowatt-hours generated during the preceding month, if available; (5)any commission-approved amendments to the schedule of rates in effect during the preceding month;and 286 §44.83.164 STATE GOVERNMENT §44.83.164 (6)an increase or decrease in the current unit price of fuel from the base price used by the commission in the determination of power costs which may be expected to result in a subsequent power cost equalization'adjustment. (c)The provisions of AS 44.83.162 relating to the determination of the amount of power cost equalization and payment of the equalization assistance apply to equalization assistance under this section.(§9 ch 118 SLA 1981;am §2 ch 133 SLA 1984) Effect of amendments.-The 1984 amendment substituted "power cost equalization"for "power cost assistance" in the introductory language of subsection (a),in two places in the first sentence of subsection (b),in paragraphs (1),(3)and (6)of subsection (b),and in subsection (c); and inserted "equalization"preceding "assistance"in two places in subsection (c). Sec.44.83.164.Equalizati,on assistance to utilities not reg- ulated by Public Utilities Commission•.(a)An electric utility that is not subject to rate regulation by the commission may receive power cost equalization if the utility is otherwise eligible for equalization assistance under AS 44.83.162 and if the utility (1)files with the commission financial data necessary to determine the power cost equalization per kilowatt-hour as prescribed by the commission and that is in COmpliance with AS 44.83.162; (2)reports monthly to the authority,within the time and in the form the authority requires,the information required in (b)of this section; (3)sets rates (A)that consider the power cost equalization provided under AS 44.83.162 by subtracting from its revenue requirements for electric services the power cost equalization per kilowatt-hour that it is eligible to receive;and (B)under which the power cost equalization provided in AS 44.83.162 is applied as a credit only against the cost of kilowatt-hours eligible for equalization assistance under AS 44.83.162 that are consumed by each customer in any month;. (4)allows audits that the commission determines are necessary to ensure compliance with this section;and (5)furnishes its electric service customers eligible under this pro- gram a notice as specified in AS 44.83.162(k). (b)An electric utility that is eligible to receive power cost equalization under this section shall report in accordance with (a)(2)of this section (1)the power cost equalization per kilowatt-hour approved by the commission; (2)the total kilowatt-hours sold to each class of customer during the preceding month; (3)the total kilowatt-hours eligible for power cost equalization under this section sold to each class of customer during the preceding month; 287 ) l §44.83.165 ALASKA STATUTES §44.83.165 I. (4)the total kilowatt-hours generated during the preceding month, if available; (5)any amendments to the schedule of rates in effect during the preceding month;and (6)an increase or decrease in the current unit price of fuel from the base price used by the commission in the determination of power costs that may be expected to result in a subsequent equalization assistance level adjustment. (c)An electric utility that is eligible to receive power cost equalization under this section may have its power cost equalization per kilowatt-hour determination changed by the commission if (1)an increase or decrease in the electric utility's cost of fuel has been verified by the commission; (2)an increase in rates has occurred based on an increase in costs and has been verified by the commission; (3)an adjustment is required after the authority has discovered discrepancies in its review of monthly data submitted by the electric utility;or (4)the authority determines that appropriations are insufficient to finance full payments to eligible electric utilities. (d)The provisions of AS 44.83.162 relating to the determination of the amount of power cost equalization and payment of the equalization assistance apply to equalization assistance under this section. (e)An application for power cost equalization by an electric utility that is eligible to receive power cost under this section does not extend the jurisdiction of the commission beyond that established by AS 42.05. (§42 ch 83 SLA 1980;am §10 ch 118 SLA 1981;am §3 ch 133 SLA 1984) Sec.44.83.165.Continuing appropriation for power cost equalization.The sum of $16,300,000 is appropriated on July 1,1984, and the sum of $21,700,000 is appropriated on July 1 of each subse- quent fiscal year from the general fund to the power cost equalization fund (AS 44.83.162).(§314 ch 171 SLA 1984) -I Revisor's notes.-Formerly AS 44.56.164.Renumbered in 1980. Effect of amendments.-This 1981 amendment rewrote this section. The 1984 amendment substituted "power cost equalization"for "power cost assistance"in the introductory language of subsection (a),in paragraph (a)(1), throughout paragraph (a)(3),in the introductory language of subsection (b),in Editor's notes.-Section 316,ch.171, SLA 1984,provides that the appropria- tions made in §§313-315 and 319 of ch. paragraphs (b)(l)and (b)(3),in two places. in the introductory language of subsection (c),and in subsections (d)and (e);inserted "equalization"preceding-"assistance"in the introductory language of subsection (a),in paragraph (a)(3)(B),and in two places in subsection (d);and made a minor word change in paragraphs (a)(1),(a)(4) and paragraph (b)(6). 171,SLA 1984,which enacted this section, are not one-year appropriations and do not lapse under AS 37.25.010. 288 §44.83.170 STATE GOVERNMENT Article 5.Power Project Fund. §44.83.170 Section 170.Power project fund Sec.44.83.170.Power project fund.(a)There is established as a separate fund the power project fund which shall be distinct from any other money or funds of the authority,and which includes only money appropriated by the legislature. (b)The authority may make loans from the power project fund (1)to electric utilities,regional electric authorities,municipalities, cities,boroughs,regional and village corporations,village councils, and nonprofit marketing cooperatives to pay the costs of (A)reconnaissance studies,feasibility studies,license and permit applications,preconstruction engineering,and design of power projects; (B)constructing,equipping,modifying,·improving,and expanding small-scale power production facilities,conservation facilities,bulk fuel storage facilities,and transmission and distribution facilities, including energy production,transmission and distribution,and waste energy conservation facilities which depen~on fossil fuel,wind power, tidal,geothermal,biomass,hydroelectric,solar or other non-nuclear energy sources;and (C)reconnaissance studies,preconstruction engineering,design, .construction,equipping,modification,and expansion of potable water supply including surface storage and groundwater sources and transmission of water from surface storage to existing distribution systems; (2)to a borrower for a power project if (A)the loan is entered into under a leveraged lease financing arrangement; (B)th~party which will be responsible for the power project is an electric utility,regional electric authority,municipality,city,borough, regional or village corporation,village council,or nonprofit marketing cooperative;and (C)the borrower seeking the loan demonstrates to the authority that the financing arrangement for the power project will reduce project financing costs below costs of comparable public power projects. (c)Before making a loan from the power project fund,the authority shall,by regulation,specify (1)standards for the eligibility of borrowers andthe types of projects to be financed with loans; (2)standards regarding the technical and economic viability and revenue self-sufficiency of eligible projects; (3)collateral or other security required for loans; (4)the terms and conditions of loans; 289 §44.83.170 ALASKA STATUTES §44.83.170 I ,~ I (5)criteria to establish financial feasibility and to measure the amount of state assistance necessary for particular projects to meet the financial feasibility criteria;and (6)other relevant criteria,standards or procedures. (d)Any loan made by the authority must be made according to the standards,criteria,and procedures established by regulation under this section. (e)Repayment of the loans shall be secured in any manner which the authority determines is feasible to assure prompt repayment under a loan-agreement entered into with the borrower.The authority may make an unsecured loan from the power project fund to a borrower regulated by the Alaska Public Utilities Commission under AS 42.05 if the borrower has a substantial history of repaying long-term loans and the capacity to repay the loan.Under a loan agreement,repayment may be deferred for 10 years or until the project for which the loan is made has achieved earnings from its operations sufficient to pay the loan,whichever is earlier. (£)Power projects are subject to the following limitations on interest and specific restrictions: (1)Power projects for which loans are outstanding from the former water resources revolving loan fund (former AS 45.86)on July 13, 1978,may receive additional financing from the power project fund;the additional financing,if granted, (A)shall be granted for a term not exceeding 50 years; (B)shall be granted at an interest rate of not less than three or more than five percent a year on the unpaid balance; (C)shall be conditioned on the repayment of loan principal and interest to begin on the earlier of (i)the date of the start of commercial operation ofthe project;or (ii)10 years from the date the loan is granted. (2)Loans for power projects (A)shall be granted for a term not to exceed 50 years;and (B)shall be granted at an interest rate which is not less than five percent and which is the lesser of (i)a rate equal to the percentage which is the average weekly yield of municipal bonds for the 12 months preceding the date of the loan,as determined by the authority from municipal bond yield rates reported in the 30-year revenue index of the Weekly Bond Buyer;or (ii)a rate determined by the authority which allows the project to meet criteria of financial feasibility established under AS 44.83.170(c). (g)Loan repayments and interest earned by loans from the power project fund shall be deposited in the state general fund. (h)The legislature may forgive the repayment of a loan made from the power project fund for a reconnaissance study or a feasibility study when the authority finds that the power project for which the loan was made is not feasible.(§1 ch 278 SLA 1976;am §16 ch 156 SLA 1978; am §§19 -23 ch 83 SLA 1980) 290 §44.83.177 STATE GOVERNMENT §44.83.177 Revisor's notes.Formerly AS 44.56.170.Renumbered in 1980. In 1984."former"was inserted before "water resources revolving loan fund"and the reference to AS 45.86.That section was repealed by sec.44,ch.83,SLA 1980. Effect of amendments.-The 1980 amendment rewrote subsections (a) through (c),(e),and (0,and added subsec- tions (g)and (hl. Article 6.General Provisions. Section 177.Reconnaissance study 179.Review of reconnaissance study by office of management and budget 181.Feasibility study and finance plan 183.Review of feasibility studies and plans of finance by office of management and budget 185.Submission to the legislature 187.Applicability of sections 189.Project construction 190.Annual audit Section 191.Limitations on issuance of bonds by the authority 192.Insurance requirements in con- struction contracts 195.Operation of projects 200.Annual report 210.Appropriations and reports 220.Public records;open meetings 224.Long-term energy plan 230.Definitions 240.Short title Sec.44.83.177.Reconnaissance study.(a)To identify power project alternatives and energy consumption patterns and needs for a community or region,the authority shall,after consultation with other state agencies and after review of information on alternative sources of energy,complete a reconnaissance study for each proposed new power project or combination of projects. (b)A reconnaissance study shall (1)identify the present and anticipated electrical and thermal energy requirements of a community or region; (2)survey all electrical and thermal energy sources and combina- tions of sources available to the community or region and evaluate the relative economic merits of alternative sources of power and heat, including energy conservation; (3)assess the effect of development of alternative sources of power and heat on the environment;and . (4)include public comment from residents of the community and adjacent area. (c)The authority,in consultation with the office of management and budget,shall adopt regulations defining (1)the methods which it shall apply to determine that the informa- tion required by (b)of this section is obtained;and (2)standard criteria and measures for comparative analysis of alter- native energy sources. (d)In completing a reconnaissance study,the authority shall consult with the Department of Community and Regional Affairs to determine the information that each may require for energy planning and the development of technology.(§24ch 83 SLA 1980;am §11 ch 118 SLA 1981;am §§3- 5 ch 133 SLA 1982;am §4 ch 79 SLA 1983;am §28 ch 63 SLA 1983) 291 ~ I §44.83.179 ALASKA STATUTES §44.83.181 Revisor's notes.Formerly AS 44.56.177.Renumbered in 1980. Cross references.-For transitional provisions related to current and pending projects as of 1980,see §47,ch.83,SLA 1980. Effect of amendments.-The 1981 amendment added subsection (d). The 1982 amendment,in subsection (a), inserted "and energy consumption pat- terns and needs"and "or region,"substi- tuted "sources of energy"for "sources of power."and added "or combination of projects"to the end.The amendment also rewrote subsection (b),which defines the scope of a reconnaissance study,and sub- stituted "alternative energy sources"for "alternative power sources"in paragraph (2)of subsection (c). The first 1983 amendment,substituted "office of management and budget"for "division of budget and management"in subsection (c). The second 1983 amendment,substi- tuted "Department of Community and Regional Affairs"for "division of energy and power development in the Department of Commerce and Economic Development" in subsection (d). Sec.44.83.179.Review of reconnaissance study by office of management and budget.(a)The office of management and budget in the Office of the Governor shall review reconnaissance studies for proposed proje-cts of the authority. (b)The review shall examine each reconnaissance study for compli- ance with the requirements of AS 44.83.177(b)and (c).The office of management and budget may approve or disapprove a reconnaissance study.If the office of management and budget disapproves of a reconnaissance study,it shall return the reconnaissance study to the authority together with a comprehensive statement of the reasons for its disapproval.The authority may amend the portions of the reconnaissance study which the office of management and budget identifies as deficient and resubmit the reconnaissance study to the office of management and budget for reconsideration. (c)For purposes of this section,a power project is approved if the reconnaissance study for the project has not been disapproved by the office of management and budget within 30 days of submission of the reconnaissance study for the project to it by the authority.(§24 ch 83 SLA 1980;am §28 ch 63 SLA 1983) Revisor's notes.-Formerly AS 44.56.179.Renumbered in 1980. Cross references.-For transitional provisions related to current and pending projects as of 1980,see §47,ch.83,SLA 1980. Effect of amendments.-The 1983 amendment,substituted "office of management and budget"for "division of budget and management"throughout this section. Sec.44.83.180.Assessment,proposal,and construction of projects. [Repealed,§44 ch 83 SLA 1980.J Sec.44.83.181.Feasibility study and finance plan.(a)Unless the reconnaissance study has been disapproved by the office of management and budget under AS 44.83.179,the authority shall com- plete a feasibility study and plan of finance for each proposed project. 292 §44.83.181 STATE GOVERNMENT §44.83.181 (b)A feasibility study shall include (1)information about the proposed project,including but not limited to estimates of total project construction costs,total project operating costs,the costs of transmission systems and reserve power require- ments,the timing and amount of anticipated returns from the com- pleted project,a benefit-to-cost ratio,the potential effect of the project on the environment of the area.that will be served by the project when completed,and the availability of alternative government financing; (2)a statement of all assumptions which affect the economic feasibility of the project,including but not limited to the discount rate and interest rate of amounts of money to be used for the project,antici- pated fuel prices,an escalation rate,state and local electric load growth,and estimates of indirect costs and benefits; (3)a comparative analysis of all reasonable alternatives to con- struction of the proposed project;and (4)information based on engineering-and design work that meets the requirements for submission of a license application for the project to the Federal Energy Regulatory Commission. (c)The plan of finance shall include recommendations of the most appropriate means to finance a project,including,but not limited to, (1)the issuance of revenue bonds of the authority; (2)the issuance of (A)general obligation bonds of the state;or (B)revenue bonds of the authority that are guaranteed or partially guaranteed by the state; (3)an appropriation from the general fund (A)to pay debt service on bonds or for other project purposes;or (B)to reduce the amount of debt financing for the project; (4)a loan from the general fund; (5)financing arrangements with other entities using leveraged leases or other financing methods;. (6)assistance from any federal agency,including,but not limited to, the Rural Electrification Administration; (7)a loa·n from the power project fund (AS 44.83.170(a));or (8)any combination of financing arrangements listed in this subsec- tion. (d)When financial assistance from the state is necessary for a project to meet financial feasibility criteria,the plan of finance shall include an estimate of the minimum amount of financial assistance required from the state.The plan of finance shall include an estimate of the present value of the financial assistance from the state,com- puted as the difference between (1)a market rate of interest,which is (A)the rate determined under AS 44.83.170(f)(2)(B)(i);or (B)the estimated interest rate for revenue bonds to be issued by the authority for the project;and 293 §44.83.183 ALASKA STATUTES §44.83.183 -I (2)the effective rate of interest because of state financial assistance provided. (e)The authority,in consultation with the office of management and budget,shall adopt regulations defining .(1)the techniques which it shall apply to determine that the infor- mation required by (b)-(d)of this section is obtained;and (2)standard criteria and measures for comparative analysis of alter- native financing arrangements.(§24 ch 83 SLA 1980;am §6 ch 133 SLA 1982;am §28 ch 63 SLA 1983;am §14 ch 161 SLA 1984) Revisor's notes.-Fonnerly AS 44.56.181.Renumbered in 1980. Cross references.-For transitional provisions related to current and pending projects as of 1980,see §47,ch.83,SLA 1980. Effect of amendments.-The 1982 amendment inserted "the costs of transmission systems and reserve power requirements"in paragraph (1)of subsec- tion (b). The 1983 amendment,substituted "office of management and budget"for "division of budget and management"in subsections (a)and (e). The 1984 amendment substituted "that" for "which"in paragraph (c)(2)(B)and deleted "or from the renewable resources investment fund (AS 37.11.050)"following the reference to the power project fund in paragraph (c)(7). Sec.44.83.183.Review of feasibility studies and plans of finance by office of management and budget.(a)-The office of management and budget in the Office of the Governor shall review the feasibility study and plan of finance for a project of the authority for compliance with the provisions of AS 44.83.181(b)-(d). (b)In its review under this section,the office of management and budget may obtain an independent evaluation ofa feasibility study and plan of finance to determine compliance with the provisions of AS 44.83.18l<b)-(d).. (c)When the office of management and budget has completed a review of the feasibility study and the plan of finance for a project under this section,it shall submit a report to the governor.The report shall examine the feasIbility study and plan of finance for compliance with the requirements of AS 44.83.181(b)-(d).The report of the office of management and budget shall include a recommendation to the governor and legislature for approval or disapproval of the project based on the office's review of the feasibility study and plan of finance for compliance with the requirements of AS 44.83.18l<b)-(d). (d)The report required by (c)of this section shall be prepared and submitted not later than 60 days after the feasibility study'and plan of finance for a proposed project have been received by the office of management and budget. (e)The report required by (c)of this section shall include a financial analysis of the proposed project of the authority that evaluates proposed bond resolutions or other financial arrangements or financial plans,security plans and,arrangements,cost and demand uncertainties,and debt volume,as they relate to the total direct and 294 §44.83.185 STATE GOVERNMENT §44.83.187 indirect indebtedness of the state.In preparing the financial analysis required by this section the office of management and budget may use the services of ouiside agencies or institutions that are not otherwise involved in the project.(§24 ch 83 SLA 1980;am §7 ch 133 SLA 1982; am §28 ch 63 SLA 1983) Revisor's notes.-Formerly AS 44.56.183.Renumbered in 1980. Cross references.-For transitional provisions related to current and pending projects as of 1980,see §47,ch.83,SLA 1980. Effect of amendments.-The 1982 amendment added subsection (e), The 1983 amendment,substituted "office of management and budget"for "division of budget and management" throughout this section. Sec.44.83.185.Submission to the legislature.(a)The authority shall submit a feasibility study and plan of finance,including a cost estimate from an independent source,for a proposed new project to the legislature.When the report of the office of management and budget examining the feasibility study and plan of finance is completed as required by AS 44.83.183,it shall be submitted to the legislature. (b)The authority may not proceed with work on the engineering or design phase of a proposed new project for which legislative approval is required until the legislature approves the proposed new project. However,the authority may proceed with the engineering or design work necessary to meet the "requirements for submission of a license application for the proposed new project to the Federal Energy Regulatory Commission without obtaining legislative approval of the proposed new project. (c)The legislatureshall consider and must approve all proposed new projects except proposed new projects that are exempt under AS 44.83.187.The legislature may approve a proposed new project only by enacting law that authorizes the project and approves a construction cost for that project.(§24 ch 83 SLA 1980;am §8 ch 133 SLA 1982; am §28 ch 63 SLA 1983;am §7 ch 89 SLA 1983) Revisor's notes.-Formerly AS 44.56.185.Renumbered in 1980. Effect of amendments.-The 1982 amendment substituted "that authorizes the project and approves a construction cost for"for "authorizing"in the second sentence of subsection (c). The fl1"8t 1983 amendment,substituted "office of management and budget"for "division of budget and management"in subsection (a). The second 1983 amendment,inserted "including a cost estimate from an inde- pendent source"in the first sentence of subsection (a). Sec.44.83.186.Final cost estimate and reauthorization by the leg- islature.[Repealed,§27 ch 89 SLA 1983.] Sec.44.83.187.Applicability of sections.(a)The provisions of AS 44.83.177 -44.83.185 and 44.83.189 apply only to a proposed new project that will generate more than 1.5 megawatts of power and 295 §44.83.187 ALASKA STATUTES §44.83.187 (1)requires an appropriation more from the state general fund,from the power project fund,or from the renewable resources funds;or (2)is bas~d on a plan of finance which requires the issuance of general obligation bonds or other pledge of the credit of the state. (b)The provisions of AS 44.83.177 -44.83.185 and 44.83.189 apply to a project that generates more than 25 megawatts of power for which the authority will issue its revenue bonds for costs of construction. (c)The provisions of AS 44.83.177 -44.83.183 do not apply when a reconnaissance study and a feasibility study for a proposed new project have.been prepared by an agency of the federal government,if the authority determines that the reconnaissance study and the feasibility study prepared by the agency of the federal government provide infor- mation sufficient to permit the authority to finance and construct the proposed new project in accordance with the requirements of this chap- ter.When a reconnaissance study and feasibility study are prepared for .a proposed new project by an agency of the federal government and the authority proposes to finance and construct the proposed new project, the authority shall provide copies of the studies and a proposed plan of finance to the office of management and budget in the Office of the Governor.The office of management and budget shall review the studies and plan of finance.Within 60 days after its receipt of the studies and plan of finance,the office of management and budget shall submit a report to the governor and legislature.The report shall exam- ine the feasibility study and plan of finance and comment upon compli- ance of the feasibility study and plan of finance with the requirements of AS 44.83.181.Approval of the legislature under AS 44.83.185 is required for a proposed new project that is exempt from the require- ments of AS 44.83.177 -44.83.183 under this subsection.The author- ity may not proceed with engineering or design work for a project until legislative approval of the project has been given under AS 44.83.185(c),except that the authority may undertake engineering or design work necessary to submit a license application forthe project to the Federal Energy Regulatory Commission without first obtaining legislative approval of the project. (d)The provisions of AS 44.83.177 -44.83.185 do not apply to (1)an addition,modification,repair,reconstruction,design,acqui- sition or construction for the purpose of completing a project; (2)the construction of an electrical transmission or distribution facility that is estimated to cost less than $3,000,000.(§24 ch 83 SLA 1980;am §1 ch 169 SLA 1980;am §28 ch 63 SLA 1983) Revisor's notes.-Formerly AS 44.56.187.Renumbered in 1980. Effect of amendments.-The 1980 amendment added "will generate more than 1.5 metawatts of power and"at the end of the introductory paragraph of sub· section (al,and substituted "funds"for "investment fund and the appropriation exceeds (Al $3,000,000,for projects for which legislative approval is sought during 1981;(B)$3,000,000 multiplied by a factor equal to a ratio determined by dividing the construction cost index of the engineering news record determined for 296 §44.83.189 STATE GOVERNMENT §44.83.192 Sec.44.83.189.Project construction.If a new project is to be desi~ed,acquired and constructed by the authority,it shall be designed,acquired and constructed as a public work of the state.For the purpose of this section and AS 44.83.187 a new project does not include (1)an addition or modification to an existing project unless the total cost of the addition or modification exceeds $1,000,000; (2)repair or reconstruction of a project;or (3)design,acquisition or construction necessary to complete a project for which bonds have been issued.(§24 ch 83 SLA 1980) January ofthe year during which a project is submitted for legislative approval,by the construction cost index of the engi- neering news record for March,1980,for projects for which legislative approval is sought after December 31,1981"at the end of paragraph (1)of subsection (a). The 1983 amendment,substituted "office of management and budget"for "division of budget and management"in subsection (c). Editor's notes.-Section 3,ch.169, SLA 1980 provides:"The projects autho- rized in sec.48 of House CS for CS for Senate Bill No.438 (Finance)am H, Eleventh Legislature,Second Session,are exempt from the amendments made in sec. 1 of this Act.",J \ Revisor's DoteS.-Formerly AS 44.56.189.Renumbered in 1980. Sec.44.83.190.Annual audit.The authority shall have its financial records audited annually by a certified public accountant. The legislative auditor may prescribe the form and content of the financial records of the authority and shall have access to these records at any time.(§1 ch 278 SLA 1976) Revisor's DoteS.-For.nerly AS 44.56.190.Renumbered in 1980. Sec.44.83.191.Limitations on.issuance of bonds by the authority.The authority may not issue bonds except after 60 days notification of its intent to issue bonds is given to the governor and to the legislature;if the legislature is in session,or to the Legislative Budget and Audit Committee,if the legislature is not in session.(§24 ch 83 SLA 1980) Revisor's DoteS.-Formerly AS 44.56.191.Renumbered in 1980. Sec.44.83.192.Insurance requirements in construction contracts.In requesting bids and awarding construction contracts under this chapter the authority may not require a contractor to obtain workers'compensation,general liability,or other required insurance from a particular insurer,agent,or broker and may not agree to pro- vide insurance to a contractor who is awarded a construction contract. (§8 ch 89 SLA 1983) 297 -1 §44.83.195 ALASKA STATUTES §44.83.224 Sec.44.83.195.Operation of projects.(a)When a project is operated by the authority,the authority shall enter into one or more contracts for the-sale of electrical power,energy,transmission capacity, or service from the project.Unless the contract is entered into under AS 44.83.380 -44.83.425,a contract entered into under this section shall meet all requirements of AS 44.83.090. (b)[Repealed,§27 ch 89 SLA 1983.J (§-24 ch 83 SLA 1980;am §§9, 27 ch 89 SLA 1983) Rev.isor's notes.-Formerly AS 44.56.195.Renumbered in 1980. Effect of amendments.-The 1983 amendment,in subsection (a),inserted "energy,transmission capacity,or service" in the first sentence and added "Unless the contract is entered into under AS 44.83.380 -44.83.425"to the beginning of the second sentence.The amendment also repealed subsection (b). -I ,I Sec.44.83.200.Annual report.Before March 1 of each year,the authority shall submit to the governor and the legislature a compre- hensive report describing operations,income and expenditures for the preceding 12-month period.(§1 ch 278 SLA 1976) Revisor's notes.-Formerly AS 44.56.200.Renumbered in 1980. Sec.44.83.210.Appropriations and reports.(a)Notwith· standing any other provision in this chapter,the authority is subject to the provisions of the Executive Bridget Act (AS 37.07). (b)The authority shall,by the 15th day of each regular legislative session,present to the legislature a report detailing project status, original costs and projected costs,particularly highlighting any costs in excess of the original cost estimates submitted for each project when that project was originally approved by the legislature.(§1 ch 278 SLA 1976;am §19 ch 156 SLA 1978) Revisor's notes.--Formerly AS 44.56.210.Renumbered in 1980. Sec.44.83.220.Public records;open meetings.The provisions of AS 09.25.110 -09.25.120 and AS 44.62.310 -44.62.312 apply to the authority.The authority shall publish a proposed agenda of its meetings and afford the public an opportunity to be heard in accor- dance with AS 44.62.312.(§1 ch 278 SLA 1976) Revisor's notes.-Formerly AS 44.56.220.Renumbered in 1980. Sec.44.83.224.Long.term energy plan.The Department of Com- merce and Economic Development,assisted by the authority,shall, after public hearings, prepare and annually revise a long-term energy 298 §44.83.230 STATE GOVERNMENT §44.83.230 plan.The plan,and its annual revisions,shall be submitted to the commissioners of the departments of the executive branch of the gov- ernment for review and to the governor for the governor's approval. After approval,the plan shall be submitted to the legislature not later than Feburary 1 of each year.The plan,and its annual revisions,shall include (1)an "end-use"study examining and reporting on the nature and amount of energy used and the purpose of its use;and (2)an energy development component for meeting projected thermal,electrical and transportation energy needs in the state at the lowest reasonable cost,including environmental and social costs,con· sistent with acceptable standards of reliability,giving an equal con· sideration as practicable to all types of energy sources (except those based on nuclear fuels)which are technologically feasible,and which promote the efficient use of facilities and fuels consistent with energy conservation goals,and the considerations-specified in AS 44.83.180(e); (3)an energy conservation component,including but not limited to, (A)conservation goals for reducing consumption of energy,iden- tifying the region for which applicable,and the source or type of energy to which the goals are applicable;and (B)specific methods and means of achieving the goals of (A)of this paragraph; (4)a component for emergency energy conservation measures applicable during times of emergency;and (5)a report on areas or subjects of research and development and demonstration projects involving alternative energy systems,local energy sources,and energy conservation.(§20 ch 156 SLA 1978;am §25 ch 83 SLA 1980) Revisor's DoteS.-Formerly AS 44.56.224.Renumbered in 1980. In 1984,"former"was inserted before the reference to AS 44.83.180 in para- graph (2).That section was repealed by §44,ch.83,SLA 1980. Effect of amendments.-The 1980 amendment rewrote the section. Sec.44.83.230.Definitions.In this chapter,unless the context requires otherwise, (1)"authority"means the Alaska Power Authority established by this chapter; (2)"bonds"means bonds,notes,or other obligations of the authority issued under this chapter; (3)"power"includes any and all electrical energy generated,distrib- uted,bought or sold for purposes of lighting,heating,power and every other useful purpose; (4)"power project"or "project"means a plant,works,system,or facility,together with related or necessary facilities and appurte- nances,including a divided or undivided interest in or a right to the capacity of a power project or project,that is used or is useful for the purpose of 299 -( I §44.83.240 ALASKA STATUTES §44.83.240 =1 (A)electrical or thermal energy production other than nuclear energy production; (B)waste energy utilization and energy conservation;or (C)transmission,purchase,sale,exchange,and interchange of elec- trical or thermal energy,including district heating or interties; (5)"public agency"means any city or other municipal corporation, political subdivision,governmental unit,or public corporation created by or under the laws of this state or of another state of the United States,and any state or the United States,and any person,board or othe~body declared by the laws of any state or the United States to be a department,agency,or instrumentality of them; (6)"person"includes a public agency in addition to the entities set out in AS 01.10.060(7); (7)"reconnaissance study"means a study conducted for the purpose of assessing the present and future electrical and thermal energy needs of an area under AS 44.83.177;· (8)"feasibility study" (A)means a study conducted for the purpose of establishing the economic and environmental practicality of completing a proposed power project under AS 44.83.181; (B)includes engineering and design work to meet the requirements for submission of a license application for a proposed new project to the Federal Energy Regulatory Commission; (9)"small-scale power production facility"means a facility which, by design,"is to produce less than 25 megawatts of power.(§1 ch 278 SLA 1976;am §§21,22 ch 156 SLA 1978;am §§26,27 ch 83 SLA 1980;am §§10,11 ch 133 SLA 1982) Revisor's notes.-Formerly AS 44.56.230.Renumbered in 1980. Effect of amendnienu.-The 1980 amendment rewrote paragraph (7),and added paragraphs (8)and (9). The 1982 amendment rewrote the defi- nition for "power project"or "project"in paragraph (4)and substituted "electrical and thermal energy needs"for "power needs"in paragraph (7). -I Sec.44.83.240.Short title.This chapter may be cited as the Alaska Power Authority Act.(§1 ch 278 SLA 1976) Revisor's notes.-Formerly AS 44.56.240.Renumbered in 1980. Article 7.Susitna River Hydroelectric Project. Section 340.Annual report 350.Legislative and executive oversight 360.Project financing Section 300.Description of project 310.Purpose of project 320.Preliminary reports 325.Restrictions on contracting 330.Construction,maintenance and oper- ation of project I 300 §44.83.300 STATE GOVERNMENT §44.83.320 Sec.44.83.300.Description of project.The Susitna River hydroelectric project consists of dams and related reservoirs,and power plants located in the Upper Susitna River Basin,and related transmission lines,facilities,and load centers,as described in the Alaska Power Authority's report required by AS 44.83.320(b).(§2 ch 169 SLA 1980) Revisor'8 DOte8.-Enacted as AS 44.56.300.Renumbered in 1980. Sec.44.83.310.Purpose of project.The primary purpose of the Susitna River hydroelectric project is to generate,transmit and distrib- ute electric power in a manner which will (1)minimize market area electrical power costs; (2)minimize adverse environmental and social impacts while enhancing environmental values to the extent possible;and (3)safeguard both life and property.(§2 ch 169 SLA 1980) Revi80r'8 DOtes.-Enacted a8 AS 44.56.310.Renumbered in 1980. Sec.44.83.320.Preliminary reports.(a)By M~rch 30,1981,the authority shall prepare and submit to the governor and to the legisla- ture a preliminary report recommending whether work should con· tinue on the Susitna River hydroelectric project,and,if the recommendation is to continue on the project,the report shall explain in detail (1)economic evaluations and preliminary environmental impact as- sessments for the Susitna River hydroelectric project and all viable alternatives; (2)the federal and state permits required to be obtained before con· struction can begin and the expected construction start date;and (3)any other information the authority considers appropriate or necessary to adequately inform ~he governor and the legislature of the status of the Susitna River hydroelectric project. (b)By April 30,1982,the authority shall prepare and submit to the governor and to the legislature a preliminary report recommending whether work should continue on the Susitna River hydroelectric project,and other valuable alternatives.If the recommendation is to continue on the Susitna River hydroelectric project,the report shall explain in detail (1)the proposed conceptual design and phases of construction of the Susitna River hydroelectric project; (2)the expected completion date of each phase of construction; (3)the expected cost of each phase of construction; (4)the costs to the state and consumers of the project under alterna- tive methods of project financing,including revenue bonds,general obligation bonds,and general fund appropriations;and 301 §44.83.325 ALASKA STATUTES §44.83.340 I (5)any other information the authority considers appropriate or necessary to adequately inform the governor and the legislature of the status of the Susitna River hydroelectric project. (c)The preliminary reports required under (a)and (b)of this section are in addition to any reports required under former AS 44.83.180 - 44.83.224.(§2 ch 169 SLA 1980) Revisor's DoteS.-Enacted as AS the reference to AS 44.83.180.That section 44.56.320(a)-{c).Renumbered in 1980.was repealed by sec.44,ch.83.SLA 1980. In 1984."former"was inserted before Sec.44.83.325.Restrictions on contracting.The authority may not enter into contracts under AS 44.83.300 -44.83.360 other than those contracts necessary to complete (1)feasibility studies,(2)the preliminary reports required by AS 44.83.320,or (3)construction ofthe Anchorage-Fairbanks intertie,until the legislature approves by law the preliminary report required under AS 44.83.320(b).(§2 ch 169 SLA 1980) Revisor's DoteS.-Enacted as AS 44.56.320(d).Renumbered in 1980. Editor's Dote.-Section 21,ch.133, SLA 1982,provides:"Notwithstanding the provisions of AS 44.83.325,the Alaska Power Authority may enter into contracts under AS 44.83.300 -44.83.360 for pre- liminary work without the approval required by AS 44.83.325.In this section, 'preliminary work'means the preparation of plans and studies and the preparation and submission of license applications,as well as other types of work.that must be completed before actual construction of the Susitna River hydroelectric project,de. scribed in AS 44.83.300,may begin.This section does not authorize the Alaska Power Authority to enter into contracts for the actual construction of the Susitna .River hydroelectric project or for the prep- aration of the site of the Susitna River hydroelectric project without the approval required by AS 44.83.325." Sec.44.83.330.Construction,maintenance and operation of project.Within one year after approval of its preliminary report sub- mitted under AS 44.83.320(b),the authority may enter into a contract for the construction of the Susitna River hydroelectric project in a manner consistent with the purpose of the project as described in AS 44.83.310.(§2 ch 169 SLA 1980) Revisor's Dotes,-Enacted as AS 44.56.330.Renumbered in 1980. Sec.44.83.340.Annual report.(a)If the Susitna River hydroelectric project is approved by the legislature under AS 44.83.325,beginning in 1983 the authority shall prepare an annual report which explains in detail (1)the status of construction on the Susitna River hydroelectric project; (2)the completion date of any phase of the Susitna River hydroelectric project which has been completed and the reasons for any 302 §44.83.350 STATE GOVERNMENT §44.83.360 deviation between the completion date and the expected completion date stated in the preliminary report required under AS 44.83.320(b); (3)the actual cost of any phase of the Susitna River hydroelectric project which has been completed and the reasons for any deviation between the actual cost and the expected cost stated in the preliminary report required tinder AS 44.83.320(b); (4)the federal and state permits necessary to begin or continue construction of the Susitna River hydroelectric project,the actual dates on which the federal and state permits necessary to begin or continue construction were obtained,and the reasons for any deviation between the actual dates and the expected dates stated in the preliminary report required under AS 44.83.320(a)or in the earlier annual reports required under this section; (5)any other information the authority considers appropriate or necessary to adequately inform the governor and the legislature of the status of the ~usitna River hydroelectric project. (b)The annual report required under (a)of this section is in addition to any reports required under AS 44.83.180 -44.83.224 and shall be submitted by March 30 of each year to the governor and to each memo ber of the legislature.(§2 ch 169 SLA 1980) Revisor's DoteS.-Enacted as AS 44.56.340.Renumbered in 1980. Sec.44.83.350.Legislative and executive oversight.The legisla- ture or the governor may provide for ongoing oversight,review and selected in-depth analysis of the Susitna River hydroelectric project plan of study.The authority shall provide all data,analyses,reports, and other information to whoever conducts the oversight,review,or analysis activities.Selected in-depth analyses shall include as- sessments of the power alternatives,financing,and power marketing sections of the Susitna River hydroelectric project plan of study.(§2 ch 169"SLA 1980) Revisor's DoteS.-Enacted as AS 44.56.350.Renumbered in 1980. Sec.44.83.360.Project financing.The Susitna River hydroelectric project shall be financed by general fund appropriations, general obligation bonds,revenue bonds,or other plans of finance as approved by the legislature.(§2 ch 169 SLA 1980) Revisor's DoteS.-Enacted as AS 44.56.360.Renumbered in 1980. 303 §44.83.361 ALASKA STATUTES §44.83.361 ] Article 8.Rural Electrificati()D Revolving Loan Fund. Section 361.Rural electrification revolving loan fund 363.Loan advisory committee Sec.44.83.361.Rural electrification revolving loan fund.(a). The rural electrification revolving loan fund is established in the Alaska Power Authority.The fund consists of (1)appropriations made to the fund;and (2)-principal payments on loans made under this section. (b)The authority may make loans from the rural electrification revolving loan fund to electric utilities certified by the Alaska Public Utilities Commission.A loan from the fund may be made only for the purpose of extending new electric service into an area of the state that an electric utility may serve under a certificate of public convenience and necessity issued by the Alaska Public Utilities Commission.A loan may be made from the fund to an electric utility if the utility invests the money necessary to provide one pole,one span of line,one transformer,and one service drop for each'consumer for whom immedi- ate service would be provided by the extension of electric service.How- ever,a loan may not be made from the fund unless (1)the loan is recommended by a loan advisory committee appointed under AS 44.83.363;and (2)the extension of electric service would provide immediate service to at least three consumers. (c)A loan from the rural electrification revolving loan fund shall bear an annual rate of interest of two percent of the unpaid balance of the loan.Interest received on a loan made under this section must be transferred monthly to the commissioner of revenue for deposit in the general fund. (d)When a loan is made by the authority under this section,the electric utility receiving the loan (1)shall,in addition to the rates that it is authorized to charge, charge the consumers served by the electric service extended with the loan proceeds an amount sufficient to pay the interest costs of the loan; (2)shall pay to the authority annually an amount equal to (A)interest of two percent on the unpaid balance of the loan;and (B)payments on the unpaid balance of the principal of the loan for each new consumer served by the electric service extended with the loan proceeds;payments on the unpaid balance of the principal of the loan shall be made at a rate equal to the difference between the actual cost of making the service connection to the consumers and the mini- mum investment per consumer required of the utility before a loan is made under (b)of this section. 304 §44.83.363 STATE GOVERNMENT §44.83.363 (e)The authority shall (1)adopt regulations necessary to carry out the provisions of this section; (2)administer the rural electrification revolving loan fund;and (3)submit to the legislature within the first 10 days of each regular legislative session a report of actions taken by the authority under this section and an accounting of the rural electrification revolving loan fund. (0 In this section, (1)."consumer"means a person,as defined in AS 01.10.060(7),or a governmental agency,if the person or governmental agency requests and offers to pay for electrical service to a facility or part of a facility; the authority shall consider a person who,or a governmental agency that,offers to pay for electrical service to several facilities to be a separate consumer for each facility,if each facility is physically sepa- rate from another facility,other than through electric service lines, and if the person or governmental agency requests and offers to pay for electrical service to each facility; (2)"facility"means a structure capable of receiVing and using elec- trical energy;and (3)"governmental agency"includes,with respect to the state or federal government or a municipal government,a legislative body, board of regents,administrative body,board,commission,committee, subcommittee,authority,council,agency,public corporation,school board,department,division,bureau,or other subordinate unIt, whether advisory or otherwise,of the state,federal,or municipal gov- ernment.(§1 ch 118 SLA 1981;am §§10 -13 ch 89 SLA 1983) EfI'ect of amendments.-The 1983 amendment.deleted "and interest" following "principal"in paragraph (a)(2). added the second sentence of subsection (C),substituted "extended with the loan proceeds"for "during the preceding year for which the loan was made"in paragraph (d)(2)(Bl,and added subsection <0. Sec.44.83.363.Loan advisory committee.When an application for a rural electrification loan is submitted to the authority under AS 44.83.361,the authority shall appoint a local advisory committee from persons residing in the area that the applicant utility is certified to serve.The loan advisory committee shall consider the loan application, and shall recommend whether the loan application is to be approved or disapproved.A favorable recommendation from the loan advisory com- 'mittee shall be based on a determination that development in the area of the proposed extension of electric service is likely to provide for full repayment of the loan under AS 44.83:361(d)within 10 years.In making that determination the committee shall consider (1)permanence of the premises to be served by the extension; (2)land use patterns in the area; 305 §44.83.380 ALASKA STATUTES §44.83.382 (3)access for the line that would be installed with loan proceeds; (4)availability of other utility service in the area;and (5)the economic feasibility of the extension of electric service with the proceeds of the loan.(§1 ch 118 SLA 1981) Article 9.Energy Program for Alaska. =1 Section 380.Program established 382.Power development fund established 384.Use of fund balance 386.Investment of fund 388.Allotment to projects 390.Reappropriation of fund balance 392.Lapse of excess appropriations 396.Operation of power project 398.Sale of power from power project Section 400.Energy conservation 410.Continuing appropriation for Susitna River hydroelectric project (Repealed effective June 30,1991] 420.Continuing appropriation for Brad· ley Lake hydroelectric project (Repealed effective June 30,1988] 425.Definitions -) Sec.44.83.380.Program established.(a)The energy program for Alaska is established.The program shall be administered by the Alaska Power Authority. (b)The energy program for Alaska is a program by which the authority may acquire or construct powe~projects with money appro- priated by the legislature to the power development fund established in AS 44.83.382.A power project may be acquired or constructed as part of the energy program for Alaska only if the project is submitted to and approved by the legislature in accordance with procedures set out in AS 44.83.177-44.83.187. (c)The provisions of AS 36.10.010 -36.10.125 apply to power projects constructed by the authority under AS 44.83.380 -44.83.425. (§1 ch 118 SLA 1981) Revisor's notes.-Enacted as AS 44.83.400.Renumbered in 1981. Sec.44.83.382.Power development fund established.(a)A power development fund is established in the Alaska Power Authority to carry out the purposes of the energy program for Alaska (AS 44.83.380 -44.83.425). (b)The fund includes (1)money appropriated to it by the legislature;and (2)[Repealed,§27 ch 89 SLA 1983.J (§1 ch 118 SLA 1981;am §27 ch 89 SLA 1983) Revisor's notes.-Enacted as AS amendment,repealed paragraph (2)of 44.83.410.Renumbered in 1981.subsection (b). Effect of amendments.-The 1983 306 , §44.83.384 STATE GOVERNMENT §44.83.384 Sec.44.83.384.Use of fund balance.(a)The fund may be used by the authority to provide money for (1)reconnaissance and feasibility studies and power project finance plans prepared under AS 44.83.177 -44.83.181; (2)the cost of a power project,including but not limited to costs of acquiring necessary licenses,preparing engineering designs,obtaining land,and constructing the power project;. (3)the defeasance of bonds,or the payment of debt service on loans for or on an issue of bonds sold in connection with a power project; (4)the cost of operating and maintaining power projects;and (5)debt service on power projects. (b)Money in the fund may be used under (a)of this section only for a power project that (1)is economically feasible;and (2)provides the lowest reasonable power cost to utility customers in the market area for the estimated life of the power project,whether operated by itself or in conjunction with other power projects in the market area,and that operates or will operate on one or more of the following: (A)renewable energy resources,including but not limited to hydroelectric power,wind,biomass,geothermal,tidal or solar energy, or a method that uses temperature differentiats or other physical properties of the ocean; (B)coal or peat; .(C)energy derived from waste heat;or (0)fossil fuel,including oil or natural gas. (c)Notwithstanding (b)(l)of this section and AS 44.83.396 - 44.83.398,the fund may be used by the authority to provide money for the cost of a .power project that is or was either constructed or owned by the United States government if the requirements of this subsection are met.The provisions of AS 44.83.177 -44.83.187 do not apply to a power project financed under this subsection.The authority may use money in the fund for the cost of a power project under this subsection K . (1)the legislature enacts a law approving the project; (2)the office of management and budget in the Office of the Gover- nor reviews a feasibility study and a plan of finance for the project and determines that the feasibility study complies with the requirements for a feasibility study submitted under AS 44.83.181(b)and that the plan of finance complies with the requirements for a plan of finance submitted under AS 44.83.181(c);and (3)the project meets the other requirements of this chapter.(§1 ch 118 SLA 1981;am §12 ch 133 SLA 1982;am §28 ch 63 SLA 1983;am §§14,15 ch 89 SLA 1983) 307 , I ~I j -I §44.83.386 ALASKA STATUTES §44.83.390 Revisor's notes.Enacted as AS 44.83.420.Renumbered in 1981. Effect of amendment8.-The 1982 amendment added subsection (cl. The first 1983 amendment,substituted "office of management and budget"for "division of budget and management"in paragraph (c)(2). The second 1983 amendment,rewrote paragraph (1)of subsection (b)and substi· tuted "AS 44.83.396 -44.83.398"for "AS 44.83.394 -44.83.398"and "or was either constructed or owned"for "constructed and owned"in the first sentence of subsection (c). Sec.44.83.386.Investment of fund.The Department of Revenue shall invest the money in the fund in accordance with AS 37.10.070 and 37.10.075.The Department of Revenue shall provide money in the fund to the authority only after costs have been incurred or amounts in the fund have been otherwise obligated under contracts for the acquisition and construction of a project.Amounts that have been obligated,but for which costs have not yet been incurred,may be segregated by the Department of Revenue or transferred to the authority only with the prior approval or agreement of the commissioner of revenue.Interest received on money that is segregated or transferred under this section must be deposited in the general fund.(§1 ch 118 SLA 1981;am §16 ch 89 SLA 1983) Revisor's note..-Enacted as AS 44.83.430.Renumbered in 1981. Effect of amendment..-The 1983 amendment,substituted the language beginning "costs have been incurred"for "a cost for a project is incurred"at the end of the second sentence and added the third and fourth sentences.. -I l Sec.44.83.388~Allotment to projects.(a)The authority shall maintain records of power project allocations from the fund for each power project (1)approved in accordance with AS 44.83.185;and (2)for which an allocation is made from an appropriation made by the legislature without specifying an appropriation to a project. (b)Income earned from investment of money appropriated to the fund shall be deposited in the general fund and may be appropriated to the fund by the legislature.(§1 ch 118 SLA 1981) Revisor's notes.-Enacted as AS 44.83.440.Renumbered in 1981. Sec.44.83.390.Reappropriation of fund balance.(a)If a power project designated by the legislature by law is not constructed,the amount appropriated to it may be reappropriated to other power projects by the legislature. (b)The legislature may reappropriate money under (a)of this sec- tion only for a power project that is economically feasible under AS 44.83.18Hb)and only if the project will serve the market area that would have been served by the power project designated by the legisla- ture and not constructed.(§1 ch 118 SLA 1981) 308 §44.83.392 STATE GoVERNMENT §44.83.396 -j Revisor's notes.-Enacted as AS 44.83.450.Renumbered in 1981. Sec.44.83.392.Lapse of excess appropriations.If at the end of construction of a power project appropriations for the power project exceed the amount required for construction of it,the excess lapses into the general fund.(§1 ch 118 SLA 1981) Revisor's notes.-Enacted as AS 44.83.460.Renumbered in 1981. 309 Sec.44.83.394.Revenue requirements.{Repealed,§27 ch 89 SLA 1983.J Sec.44.83.396.Operation of power project.(a)A power project that is acquired or constructed as part ofthe energy program for Alaska is owned,and ahall be administered,by the authority. (b)When a power project has been acquired or constructed by the authority,the project may be operated for the authority under a contract or lease entered into by a qualified utility and the authority. (c)The authority shall enter into a contract or lease under reason- able terms and conditions to permit the applicant utility to operate the power project when the applicant utility is the only wholesale power customer to be served directly by the power project unless the authority determines a utility making application for a contract or lease to operate a power project is not a qualified utility or is not capable of operating that power project efficiently and in a manner that is consis- tent with national standards for the industry and with agreements with bondholders. (d)The authority shall adopt regulations to determine the manner of selecting a qualified utility to operate a power project under a contract or lease when there is more than one wholesale power customer to be served directly by the power project. (e)When the authority permits a power project to be operated by a qualified utility under a contract or lease,the authority shall (1)review and approve the annual budget for the operation and maintenance of the power project;and (2)assure that the project is being operated efficiently and in a manner that is consistent with national standards for the industry and agreements with bondholders.(§1 ch 118 SLA 1981;am §§17 -19 ch 89 SLA 1983) Revisor's note8.-Enacted as AS 44.83.480.Renumbered in 1981. Effect of amendments.-The 1983 amendment,deleted "by the state" following "is owned"in subsection (a), inserted "a qualified utility or is not"near the end of subsection (c),added the lan- guage beginning "efficiently and in a manner that is consistent"to the end of subsection (c),added "and"to the end of paragraph (1)of subsection (e),and added "and agreements with bondholders"to the end of paragraph (2)of subsection (e). I -I 1 j -I §44.83.398 ALASKA STATUTES §44.83.398 -I Sec.44.83.398.Sale of power from power project.(a)The authority shall sell power produced from power projects acquired or constructed under the energy program for Alaska.For purposes of this section,Lake Tyee,Swan Lake,Solomon Gulch,and Terror Lake hydroelectric facilities are considered to be one power project.This power project is referred to as the initial project (b)The authority shall establish a wholesale power rate structure applicable to sales of power to the customers of a power project as follows: (1)-The authority shall establish and maintain a separate wholesale power rate applicable to each power project that it has acquired or constructed under the energy program for Alaska,other than a project described in (1)of this section.The wholesale power rate established by the authority for the initial project shall be a rate calculated under this paragraph except that the portion of the rate applicable to (A)and (C) of this paragraph shall be adjusted for the hydroelectric facilities in the initial project as set out in (3)of this subsection.The wholesale power rate shall be computed by the authority annually,or more frequently as may be necessary,and shall equal the rate that the authority esti- mates is necessary to produce revenue that is sufficient to pay (A)operation,maintenance,and equipment replacement costs of the power project; (B)the power project's proportionate share of the debt service on state loans and bonds for all power projects in the energy program for Alaska,determined in accordance with (g)of this section; (C)safety inspections and investigations of the power project by the authority. (2)[Repealed,§7 ch 169 SLA 1984.J (3)For the purposes of determining amounts to be allocated to each hydroelectric facility in the initial project under (l)(A)and (l)(C)of this subsection,the authority shall determine for each hydroelectric facility its individual operation,maintenance,equipment replacement,safety inspection,and investigation costs.. (c)The authority shall transmit all the money that it receives under (a)of this section to the commissioner of revenue for deposit in the state general fund except for money it has pledged or otherwise covenanted to secure bonds. (d)[Repealed,§8 ch 169 SLA 1984.] (e)After determining the wholesale power rate for a power project under the provisions of this section,the authority may adjust the rate or change the rate provisions to insure that the revenue derived from that power project and the aggregate revenues of the authority will be adequate to comply with the rate covenants and other agreements contained in any trust indenture or trust agreement entered into by the authority for the seurity ofthe holders of bonds issuedto finance power projects in the energy program for Alaska.The authority may agree with a purchaser of power to limit rate increases caused by debt service payable by the authority on subsequent projects. 310 §44.83.398 STATE GOVERNMENT §44.83.398 (0 The provisions ofCb)of this section do not apply to an intertie that is authorized as a separate project under AS 44.83.380.The authority shall establish and maintain separate power rate schedules applicable to each intertie that it has acquired or constructed as a separate power project under the energy program for Alaska.The power rate schedules shall produce sufficient revenue from utilities connected by the intertie to pay (1)operation,maintenance,and equipment replacement costs of the intertie;(2)debt service of the intertie;and (3)safety inspections and investigations of the intertie by the authority.If the authority determines that an intertie has ceased to function as a separate project and has become a part of one or more other power projects and has become a part of one or more other power projects as a transmission line,the power rate schedules established under this subsection shall be terminated and a wholesale power rate applicable to the former intertie shall be calculated under Cb)of this section for the project or projects of whi.ch it has become a part. (g)For the purposes of (b)(1)(B)of this section,a power project's proportionate share of debt service on state loans and bonds for all power projects in the energy program for Alaska is equal to the state's investment in the power project divided by the state's investment in all power projects in the energy program for Alaska and multiplied by the debt service on state loans and bonds for all power projects in the energy program for Alaska.In this subsection (1)"state's investment in the power project"includes allstate money invested in a power project,including loans,grants,and proceeds from bonds,less the principal repayments on the project's proportionate share of debt service on state loans and bonds; (2)"state's investment in all power projects in the energy program for Alaska"includes all state money invested in the power projects, other than interties,in the energy program for Alaska,including loans, grants,and proceeds from bonds,less the principal repayments on bonds and state loans issued for the power projects. (h)Notwithstanding (g)of this section,in the 1983 state fiscal year the proportionate share of debt service under (b)of this section, expressed as a rate,for a power project for which a construction contract has been awarded before June 25,1982 may not exceed the average debt service component of the wholesale power rate for all power projects in the energy program for Alaska.The limit imposed by this subsection shall be increased in the 1984 state fiscal year to four percent above the average debt servicecomponent of the wholesale power rate for all power projects in the energy program for Alaska and by an additional four percent above that average in each succeeding state fiscal year.If application of this subsection results in the produc- tion of insufficient revenue to pay the total debt service for all projects in the energy program for Alaska,a project that does not have its share of debt service limited under this subsection shall be subject to a rate 311 §44.83.398 ALASKA STATUTES §44.83.398 in addition to the rate established under (b)of this section.The addi- tional rate is the rate that the authority estimates is necessary to produce revenue that is sufficient to pay the difference between the total debt service for all projects in the energy program for Alaska and the revenue actually produced to pay that debt service,multiplied by a fraction whose numerator is the total cost of the project and whose denominator is the total cost of all of the projects that are subject to the additional rate.In this subsection,"projects in the energy program for Alaska"does not include an intertie that is authorized as a separate project as described in (£)of this section. (i)The authority may place in a separate interest bearing account money appropriated to the authority as a loan for the purpose of meeting the operating expenses of a facility in the initial project.The money may be used to replace amounts which were expected to be paid by a utility potentially served by a facility in the initial project,which has not entered into a power sales agreement with the authority. Repayment of the amount loaned must be made from revenues attributable to power sales from that facility,as limited by the terms of power sales agreements with power purchasers from that facility.A loan made in accordance with this subsection is not a state loan for purposes of calculating the wholesale power rate under (b)(l)of this section.(§1 ch 118 SLA 1981;am §§13 -16 ch 133 SLA 1982;am §§20 -23 ch 89 SLA 1983;am §125 ch 6 SLA 1984;am §§2-8 ch 169 SLA 1984) 312I Revisor's notes.-Enacted as AS 44.83.490.Renumbered in 1981. Effect of amendments.-The 1982 amendment,in subsection (b),substituted "a power project"for "the power project"in the introductory language,substituted "separate"for "single"and "each power project"for "all power projects"in the first sentence of paragraph (1),added "other than a project described in (f)of this sec· tion"to the end of the first sentence of paragraph (1),inserted "or more frequently as may be necessary"in the introductory language of the second sen- tence of paragraph (1),substituted "power project"for "power projects"in subpara· graph (1)(Al and (e),added "the power project's proportionate share of the"to the beginning of subparagraph (1)(B),substi· tuted the language beginning "on state loans and bonds"for "of the power projects"in subparagraph (1)(B),substi- tuted "separate"for "single"and "each power project that is"for "all power projects that it has"in the first sentence of paragraph (2),inserted "or more frequently as may be necessary"in the introductory language of the second sen- tence of paragraph (2),substituted "power project"for "power projects"in subpara- graph (2)(A)and (2)(B)(iii),and substi· tuted the present provisions of subparagraph (2)(B)(ii)for the former pro- visions,which read:"debt service of power projects by the authority;and."In subsec- tion (c),the amendment substituted "under (a)of this section"for "under (b)of this section"and "money it has pledged to secure bonds in accordance with contracts with bondholders"for "the money it receives under (b)(1)(A)and (B)and (b)(2)(B)(i)and (ii),or the money it would .have received under (b)(l)(A)and (B)and (b)(2)(B)(i)and (ii)of this section if those items had been used in part to establish the wholesale power rate in effect at the time the money is received by the author- ity."In subsection (e),the amendment sub- stituted "a wholesale"for "the whol~sale" and "or (0"in the first sentence and added the second sentence.The amendment also added subsections (0 -(h). The 1983 amendment,substituted "July 1,1991"for "July 1,1986"near the beginning of paragraph (2)of subsection (b),substituted "or otherwise covenanted §44.83.400 STATE GoVERNMENT §44.83.420 to secure bonds"for "to secure bonds in accordance with contracts with bondholders"at the end of subsection (c), rewrote subsection (e),and added the last sentence of subsection (h). The first 1984 amendment made a tech· nical change in the last sentence in subsec· tion(O. The second 1984 amendment added sub- section m,repealed fonner paragraph (2) of subsection (b),relating to a separate wholesale power rate beginning July 1, 1991,and repealed fonner subsection (d), relating to industrial consumer rates.The 1984 amendment also,in subsection (a), deleted fonner paragraphs (1)and (2)and the former last sentence in the introductory paragraph,relating to a util- ity that purchases power produced by a power project of the authority,and,in the remaining language,added the last two sentences;in subsection (b),substituted "the customers"for "its customers at the busbar"in the introductory language, inserted the second sentence in the introductory paragraph of paragraph (1), and added paragraph (3);in subsection (e), added the second sentence and substituted "energy program"for "Energy Program" in the C11'st sentence;and changed the internal reference in the first sentence in the introductory paragraph of subsection (g). \. Sec.44.83.400.Energy conservation.The authority shall ensure (1)that communities that benefit from the energy program for Alaska implement cost-effective energy conservation measures for residences,commercial and public buildings,and industries;and (2)that communities shall fulfill their responsibilities under (1)of this section by cooperating with state agencies concerned with development and conservation of energy,including but not limited to (A)the Alaska Public Utilities Commission; (B)the Department of Community and Regional·Affairs;and .(C)the division of business loans,Department of Commerce'and Economic Development.(§1 ch 118 SLA 1981;am §5 ch 79 SLA 1983) ReviBor's notes.-Enacted as AS 44.83.500.Renumbered in 1981. Effect of amendments.-The 1983 amendment.substituted "Department of Community and Regional Affairs"for "division of energy and power development.Department of Commerce and Economic Development"in paragraph (2)(B). Sec.44.83.410.Continuing appropriation for Susitna River Hydroelectric project.[Repealed effective June 30,1991]The sum of $100,000,000 is appropriated on July 1,'1984 and the sum of $200,000,000 is appropriated on July 1 of each subsequent fiscal year from the general fund to the authority for deposit in the power development fund (AS 44.83.382)for the purpose of equity investment in,and rate stabilization for,the Susitna River hydroelectric project. (§314 ch 171 SLA 1984;r §317 ch 171 SLA 1984) -I Polltponed repeaL -This section is repealed effective June 30,1991. Editor's notes.-Section 316,ch.171, SLA 1984,provides that the appropria- tions made in §§313-315 and 319 of ch. 171.SLA 1984,which enacted this section. are not one-year appropriations and do not lapse under AS 37.25.010. Sec.44.83.420.Continuing appropriation for Bradley Lake hydroelectric project.[Repealed effective June 30,1988.]The sum 313 ,-I §44.83.425 ALASKA STATUTES §44.83.425 of $50,000,000 is appropriated on July 1,of each fiscal year from the general fund to the authority for deposit in the power development fund (AS 44.83.382)for the purpose of equity investment in,and rate stabilization for,the Bradley Lake hydroelectric project.(§314 ch 171 SLA 1984;r §318 ch 171 SLA 1984) Postponed repeal.-This section is repealed effective June 30,1988. Editor's notes.-Section 316,ch.171, SLA 1984,provides that the appropria- tions made in §§313-315 and 319 of ch. 171,SLA 1984,which enacted this section, are not one-year appropriations and do not lapse under AS 37.25.010. -I II Sec.44.83.425.Definitions.In AS 44.83.380 -44.83.425, (1)"bus bar"means the substation that serves as the delivery point from the generation and transmission system of the authority to the transmission and distribution system of the utility; (2)"debt service"means the amounts covenanted with respect to,or pledged to pay,bonds under a trust agreement securing bonds; (3)"fund"means the power development fund established by AS 44.83.382; (4)"industrial consumer"means a customer of a utility which customer has a peak power demand in excess of 500 kilowatts and uses the power principally for (A)manufacturing; (B)pipeline transportation; (C)the recovery or processing of minerals; (D)the processing of timber,agricultural,or seafood products or their by-products;or .(E)the operation of facilities owned by the federal government; (5)"qualified utility"means an electric utility that is certified by the Alaska Public Utilities Commission to serve all or part of a market area that i~served or will be served by the power project,and that the authority detennines is capable of operating and maintaining the power project.(§1 ch 118 SLA 1981;am §24 ch 89 SLA 1983) Revisor's notes.-Enacted 88 AS amendment,rewrote the definition of 44.83.510.Renumbered in 1981."debt service"in paragraph (2). Effect of amendments.-The 1983 1 I 1 =i -, I ) I I ) I I I ) ) I I I 1 I, NOTICE -\! A NOTATIONAL SYSTEM HAS BEEN USED TO DENOTE DIFFERENCES BETWEEN THIS AMENDED LICENSE APPLICATION AND THE LICENSE APPLICATION AS ACCEPTED FOR FILING BY FERC ON JULY 29,1983 This system consists of placing one of the following notations beside each text heading: (0)No change was made in this section,it remains the same as was presented in the July 29,1983 License Application (*)Only minor changes,largely of an editorial nature,have been made (**)Major changes have been made l.n this section (***)This is an entirely new section which did not appear l.n the July 29,1983 License Application ] )' ) =1 ) I ) l ) I VOLUME COMPARISON -I VOLUME NUMBER COMPARISON LICENSE APPLICATION AMENDMENT VS.JULY 29,1983 LICENSE APPLICATION JULY 29,1983 AMENDMENT APPLICATION EXHIBIT CHAPTER DESCRIPTION VOLUME NO.VOLUME NO. A B C D E Entire Entire App.Bl App.B2 App.B3 Entire Entire App.Dl 1 2 Tables Figures Figures 3 Project Description Project Operation and Resource Utilization MAP Model Documentation Report RED Model Documentation Report RED Model Update Proposed Construction Schedule Project Costs and Financing Fuels Pricing General Description of Locale Water Use and Quality Fish,Wildlife and Botanical Resources (Sect.1 and 2) Fish,Wildlife and Botanical Resources (Sect.3) Fish,Wildlife and Botanical Resources (Sect.4,5,6,&7) 1 2 3 4 4 S S S 6 6 7 8 9 10 11 1 2 &2A 2B 2C 1 1 1 SA 5A 5A 5B 5B 6A 6B 6A 6B 6A 6B Socioeconomic Impacts Geological and Soil Resources 4 5 6 Historic &Archaeological Resources 12 12 12 7 7 7 7 8 9 10 11 Recreational Resources Aesthetic Resources Land Use Alternative Locations, and Energy Sources Agency Consultation Designs 13 13 13 14 14 8 8 8 9 lOA lOB F F G Entire Entire Entire Project Design Plates Supporting Design Report Project Limits and Land Ownership Plates 15 16 17 3 4 ,] I ~ I I i~-j -I --I I I I i II SUMMARY TABLE OF CONTENTS SUMMARY TABLE OF CONTENTS SUSITNA HYDROELECTRIC PROJECT LICENSE APPLICATION EXHIBIT A PROJECT DESCRIPTION A-I-2 A-I-4 A-I-6 A-I-9 A-I-IO A-I-13 A-I-I5 A-I-I5 A-I-I8 A-I-I9 A-I-22 A-I-23 A-I-25 A-I-29 A-I-2 Page No. ·.. . · .. ·.. 1.1 -General Arrangement (**)• . • • • 1.2 -Dam Embankment (**).•••••.•••••••• 1.3 -Diversion (**).••.••• 1.4 -Emergency Release Facilities (**)••••• 1.5 -Outlet Facilities (**)• 1.6 -Spillway (**)•••• 1.7 -This section deleted.• •••• 1.8 -Power Intake (**)•••••• 1.9 -Power Tunnels and Penstocks (**). 1.10 -Powerhouse (**)• • • • • • 1.11 -Tailrace (**). • • • • .••• 1.12 -Main Access Plan (**)••...•••. 1.13 -Site Facilities (**).••.• 1.14 -Relict Channel (***)••••••.••••. 1 -PROJECT STRUCTURES -WATANA STAGE I (**)• Title 1 I J I I ! 2 -RESERVOIR DATA -WATANA STAGE I (**)•·..·..• • • A-2-I 3 -TURBINES AND GENERATORS -WATANA STAGE I (**)· ....A-3-1 3.1 -Unit Capacity (**). . ....··· · · ···A-3-1 3.2 -Turbines (***)...····· · · · A-3-1 3.3 -Generators (**)··· ···A-3-1 3.4 -Governor System (0). ...··· · A-3-3 4 -APPURTENANT MECHANICAL AND ELECTRICAL EQUIPMENT - WATANA STAGE I (**)••••••••••••••••·.A-4-1 4.1 -Miscellaneous Mechanical Equipment (**) 4.2 -Accessory Electrical Equipment (**).••• 4.3 -SF6 Gas-Insulated 345 kV Substation (GIS)(***) A-4-1 A-4-5 A-4-12 5 -TRANSMISSION FACILITIES FOR WATANA STAGE I (0)• •·..A-5-1 ---j I 5.1 -Transmission Requirements (0) 5.2 -Description of Facilities (0) 5.3 -Construction Staging (0)••• · . .. . ...·.. .. .. . A-5-1 A-5-1 A-5-I1 851014 1. SUMMARY TABLE OF CONTENTS (cont'd) EmIBIT A PROJECT DESCRIPTION 8 -TURBINES AND GENERATORS -DEVIL CANYON STAGE II (**) . ..... . ... . . 9 -APPURTENANT EQUIPMENT -DEVIL CANYON STAGE II (0). .......... 1 ~ I J ) J I' I l I i I A-6-1 A-6-1 A-6-2 A-6-4 A-6-6 A-6-8 A-6-10 A-6-12 A-ll-1 A-6-12 A-6-13 A-6-14 A-6-17 A-6-17 A-6-18 A-8-1 A-8-1 A-8-1 A-8-2 A-1O-1 A-9-1 A-7-1 A-8-1 A-ll-1 A-1l-3 A-11-5 A-1l-6 A-9-1 A-9-3 A-9-6 Page No. .. .. •• • . . . . ... ... (**) .. . (***) ... . ... . . . -General Arrangement (**) -Arch Dam (**) -Saddle Dam (**) -Diversion (**). -Outlet Facilities'(**) -Spillway (**)•••. -Emergency Spillway • • (This section deleted) Power Facilities (*)•• Penstocks (**)• • • • -Powerhouse and Related Structures -Tailrace Tunnel (*)• • • . -Access Plan (**)••• -Site Facilities (*)• 11.1 -General Arrangement (***) 11.2 -Dam Embankment (***)••• 11.3 -Diversion (***)••••• 11.4 -Emergency Release Facilities 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 - 6.9 - 6.10 6.11 6.12 6.13 8.1 -Unit Capacity (**) 8.2 -Turbines (**) 8.3 -Generators (0)•• 8.4 -Governor System (0) 9.1 -Miscellaneous Mechanical Equipment (0)•• 9.2 -Accessory Electrical Equipment (0)••• 9.3 -Switchyard Structures and Equipment (0). Title 6 -PROJECT STRUCTURES -DEVIL CANYON STAGE II (**) 7 -DEVIL CANYON RESERVOIR STAGE II (*) 10 -TRANSMISSION LINES -DEVIL CANYON STAGE II (**) 11 -PROJECT STRUCTURES -WATANA STAGE III (***)• 851014 ii 1 j ~ SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT A PROJECT DESCRIPTION Title Page No. 11.5 -Outlet Facilities (***)···· · · ·11.6 -Spillway (***).· ···11.7 - Power Intake (***)·· ··· ·· I 11.8 -Power Tunnel and Penstocks (***) 11.9 -Powerhouse (***)· ·· ·· ·11.10 -Trailrace (***)· ·· · ·· ··· ·· · ·11.11 -Access Plan (***)····· ···· ··. 11.12 -Site Fad li ties (***)·· ·11.13 -Relict Channel (***) A-Il-6 A-11-7 A-11-8 A-11-11 A-ll-ll A-11-13 A-l1-13 A-11-13 A-ll-13 12 -RESERVOIR DATA -WATANA STAGE III (***)·..•••·.A-12-1 14.1 -Miscellaneous Mechanical Equipment (***). 14.2 -Accessory Electrical Equipment (***).....• 14 -APPURTENANT MECHANICAL AND ELECTRICAL EQUIPMENT - WATANA STAGE III (***)•••••••••••••• 15 -TRANSMISSION FACILITIES -WATANA STAGE III (***) ..... . . .. . .. .... . .. ... A-14-1 A-14-1 A-13-1 A-13-1 A-13-1 A-13-1 A-13-1 A-14-1 A-15-1 A-15-1 A-15-1 A-16-1 A-17-1 • • ·.. ·....· .. · . . ........... Transmission Requirements (***)• switching and Substations (***)• 15.1 15.2 13 -TURBINES AND GENERATORS -WATANA STAGE III (***) 13.1 -Unit Capacity (***)•••••• 13.2 -Turbines (***) 13.3 ~Generators (***) 13.4 -Governor System (***) 17 -REFERENCES 16 -LANDS OF THE UNITED STATES (**) I I l I j I \ 'l 1 851014 iii SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT B PROJECT OPERATION AND RESOURCE UTILIZATION J 1.1 -Previous Studies (***).••• 1.2 -Plan Formulation and Selection Methodology (***). 1.3 -Damsite Selection (***)•••••••••• 1.4 -Formulation of Susitna Basin Development Plans (***). . . . . . . • . • • . . . . • . 1.5 -Evaluation of Basin Development Plans (***)• Title 1 -DAMSITE SELECTION (***)• • • ••• • • • •• • • .. . Page No. B-1-1 B-1-1 B-1-4 B-1-5 B-1-12 B-1-17 .~ l 2 -ALTERNATIVE FACILITY DESIGN,PROCESSES AND OPERATIONS (***).............• • ·...B-2-1 2.1 -Susitna Hydroelectric Development (***)• 2.2 -Watana Project Formulation (***)••••• 2.3 -Selection of Watana General Arrangement (***)•• 2.4 -Devil Canyon Project Formulation (***). 2.5 -Selection of Devil Canyon General Arrangement (***)• • • • . • • • • • • • 2.6 -Selection of Access Road Corridor (***) 2.7 -Selection of Transmission Facilities (***)•• 2.8 -Selection of Project Operation (***)•.•••• B-2-1 B-2-1 B-2-22 B-2-48 B-2-60 B-2-67 B-2-83 B-2-131 3 -DESCRIPTION OF PROJECT OPERATION (***)•• • ••• • • B-3-1 3.1 -Hydrology (***)•••.••.•••••••••• 3.2 -Reservoir Operation Modeling (***)•.••••. 3.3 -Operational Flow Regime Selection (***)••• B-3-1 B-3-6 B-3-20 4 -POWER AND ENERGY PRODUCTION (***)• • ••• • • • • • • B-4-1 4.1 -Plant and System Operation Requirements (***) 4.2 -Power and Energy Production (***)•... B-4-1 B-4-10 5 -STATEMENT OF POWER NEEDS AND UTILIZATION (***)• • B-5-1 5.1 -Introduction (***)•••••••••••• 5.2 -Description of the Railbelt Electric Systems (***) 5.3 -Forecasting Methodology (***)•• 5.4 -Forecast of Electric Power Demand (***) B-5-1 B-5-1 B-5-17 B-5-47 ·.......6 -FUTURE SUSITNA BASIN DEVELOPMENT (***) 7 -REFERENCES 851014 .......... . ...... iv ... B-6-1 B-7-1 SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT B -APPENDIX Bl MAN-IN-THE-ARCTIC PROGRAM (MAP) TECHNICAL DOCUMENTATION REPORT STAGE MODEL (VERSION A85.1) REGIONALIZATION MODEL (VERSION A84.CD) SCENARIO GENERATOR -I Title Page No. Stage Model . ....1-1 2-1 3-1 4-1 5-1 6-1 7-1 8-1 9-1 10-1 11-1 12-1 13-1 ·... ·. .. · . ·. Introduction • • • • • • • • • • • • • Economic Module Description • • • • Fiscal Module Description • • • • • • • • • • • • Demographic Module Description • • • • • • • Input Variables •••••••• Variable and Parameter Name Conventions Parameter Values,Definitions and Sources •••• Model Validation and Properties Input Data Sources • • • • • • • • • • • • • • • • • • Programs for Model Use • • • • • Model Adjustments for Simulation • Key to Regressions • • Input Data Archives 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Regionalization Model 1.Model Description ····1 ----'2.Flow Diagram ..······5I3.Model Inputs ..·.····7 4.variable and Parameter Names .· ···.·.9 5.Parameter Values · ····13 6.Model Validation · ·· · · ·.·.. .31 7.Programs for Model · · .····.·38 8.Model Listing .·..·39 9.Model Parameters · · 57 10.Exogenous,Policy,and Startup Values 61 Scenario Generator l Introduction • • • • • • • • • • • • • • • 1.Organization of the Library Archives. 2.Using the Scenario Generator •••• 3.Creating,Manipulating,Examining,and Printing Library Files • • • • 4.Model Output ••••••••••• 1 1 8 14 22 851014 v SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT B -APPENDIX B2 RAILBELT ELECTRICITY DEMAND (RED)MODEL TECHNICAL DOCUMENTATION REPORT (1983 VERSION) Title 1 -INTRODUCTION •.. . .. .... Page No. 1.1 8 -THE PROGRAM-INDUCED CONSERVATION MODULE 6 -THE BUSINESS CONSUMPTION MODULE 7 -PRICE ELASTICITY • • • • • • • • 5 -THE RESIDENTIAL CONSUMPTION MODULE 3.1 4.1 15.1 6.1 \ 7.1 8.1 j 9.1 J. 10.1 11.1 I· 12.1 13.1 \ -i l I 2.1 . . . .. . . ·. . ·. . . . . .. · ... .. . .. .... . . . .. . .. . . . . . . . . .... .. . .. .. . . . 2 -OVERVIEW • • 10 -LARGE INDUSTRIAL DEMAND 3 -UNCERTAINTY MODULE 11 -THE PEAK DEMAND MODULE 12 -MODEL VALIDATION 13 -MISCELLANEOUS TABLES 4 -THE HOUSING MODULE 9 -THE MISCELLANEOUS MODULE 851014 vi EXHIBIT B -APPENDIX B3 RAILBELT ELECTRICITY DEMAND (RED)MODEL CHANGES MADE JULY 1983 TO AUGUST 1985 2 -RED MODEL PRICE ADJUSTMENT REVISIONS 6 EFFECT OF THE MODEL CHANGES ON THE FORECASTS SUMMARY TABLE OF CONTENTS (cont'd) Page No. 1.1 2.1 3.1 4.1 5.1 6.1 ... .. . . . . . ... . ... . .....1 -INTRODUCTION Title 3 -RESIDENTIAL CONSUMPTION MODULE 5 -PEAK DEMAND 4 -BUSINESS SECTOR 1 I I I ! -1 I I I j 1 :_j I -I I l ) I j 851014 vii SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT C PROPOSED CONSTRUCTION SCHEDULE Title Page No. -1 1 -1 I 1 -WATANA STAGE I SCHEDULE (**)• • • • • • • • • •$• • C-1-l · . 1.1 -Access C*)••••••• 1.2 -Site Facilities C**) 1.3 -Diversion C**) 1.4 -Dam Embankment C**)•••••••••••• 1.5 -Spillway and Intakes C**) 1.6 -Powerhouse and Other Underground Works C**)• 1.7 -Relict Channel C**)••••••••••••• 1.8 -Transmission Lines/Switchyards C*)•••• 1.9 -General C**)••••••••••• C-1-2 C-1-2 C-1-2 C-1-2 C-1-3 C-1-3 C-1-3 C-1-3 C-1-3 2 -DEVIL CANYON STAGE II SCHEDULE (**)••• •·....".C-2-1 2.1 -Access C**).· · ···· ·· ·· · ··2.2 -Site Facilities C**)········ ·2.3 -Diversion C*)· · · ·· · ····2.4 -Arch Dam C**)······ ··· ·········2.5 Spillway and Intake C*) 2.6 -Powerhouse and Other Underground Works Co)···2.7 -Transmission Lines/Switchyards C*)· ·· · ·2.8 -General C*).··· · · ·· C-2-1 C-2-1 C-2-1 C-2-1 C-2-2 C-2-2 C-2-2 C-2-2 3.1 -Access C***)·· ··3.2 -Site Facilities C***)·· · · ·····3.3 -Dam Embankment C***)· · · · ····3.4 -Spillway and Intakes C***)···· · ·3.5 -Powerhouse and Other Underground Works C**)·3.6 -Relict Channel C***)·· · ·· ···3.7 -Transmission Lines/Switchyards (***) 3.8 -General C***)·· · · ·· · ··· ··· 4 - EXISTING TRANSMISSION SYSTEM (***)• •• •• •··• • 3 -WATANA STAGE II I SCHEDULE (***)•·...•• ••• • • C-3-1 C-3-1 C-3-1 C-3-1 C-3-2 C-3-2 C-3-2 C-3-2 C-3-2 C-4-1 851014 viii SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT D PROJECT COSTS AND FINANCING 1.1 -Construction Costs (**) 1.2 -Mi tigation Costs (**)••.•.•..•. 1.3 -Engineering and Administration Costs (*)•••• 1.4 -Operation,Maintenance and Replacement Costs (**) 1.5 -Allowance for Funds Used During Construction (AFDC)(**)•••.••.•••.• 1.6 -Escalation (**)••••••••••••.. 1.7 -Cash Flow and Manpower Loading Requirements (**). 1.8 -Contingency (*).......•••.•..•.• 1.9 -Previously Constructed Project Facilities (*) Title 1 -ESTIMATES OF COST (**).. .............. Page No. D-1-1 D-I-1 D-1-6 D-I-7 D-1-10 D-1-11 D-l-12 D-I-12 D-1-13 D-I-13 2 -EVALUATION OF ALTERNATIVE EXPANSION PLANS (***)•...D-2-1 ·.. .·. . . 2.1 -General (***)•••••'•••••••••. 2.2 -Hydroelectric Alternatives (***) 2.3 Thermal Alternatives (***)••• 2.4 -Natural Gas-Fired Options (***)• 2.5 -Coal-Fired Options (***)••.••• 2.6 -The Existing Railbelt Systems (***) 2.7 -Generation Expansion Before 1996 (***) 2.8 -Formulation of Expansion Plans Beginning in 1996 (***)••.•.•••••••• • 2.9 Selection of Expansion Plans (***)••• 2.10 -Economic Development (***)•••• 2.11 -Sensitivity Analysis (***)••••••••••'. 2.12 -Conclusions (***)•••••••.•••• D-2-1 D-2-1 D-2-10 D-2-10 D-2-19 D-2-24 D-2-27 D-2-28 D-2-33 D-2-39 D-2-44 D-2-46 4.1 -General Approach and Procedures (***) 4.2 -Financing Plan (***)•.•••• 4.3 -Annual Costs (***)•••••••••• D-3-1 D-3-1 D-3-1 D-4-1 D-4-1 D-4-1 D-4-3 • ••• ......... ix 3 -CONSEQUENCES OF LICENSE DENIAL (***) 3.1 -Statement and Evaluation of the Consequences of License Denial (***).. 3.2 -Future Use of the Damsites if the License is Denied (***).•• • • • • 4 -FINANCING (***)•••••••••••••••• 851014 ! ! I -I I I SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT D PROJECT COSTS AND FINANCING Title 4.4 -Market Value of Power (***)• 4.5 -Rate Stabilization (***) 4.6 -Sensitivity of Analyses (***) 5 -REFERENCES (***) 851014 .. .. . .. . .......... .. x Page No. D-4-4 D-4-4 D-4-4 D-5-1 I ~ i j I I -i I \ I SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT D -APPENDIX Dl FUELS PRICING 2.1 -The Sherman H.Clark Associates Forecast (***) 2.2 -The Composite Oil·Price Forecast (***) 2.3 -The Wharton Forecast (***)••••. 2 -WORLD OIL PRICE (***)• • ·... ... . ... ... Dl-2-1 D1-1-l Page No. Dl-2-1 Dl-2-2 Dl-2-5 ·.• • ·....·.· . .. ..1 -INTRODUCTION (***) Title 3 -NATURAL GAS (***)... . .·...• ••·.·....Dl-3-1 5 -DISTILLATE OIL (***)•.• •· · · • •· · •·•• • • Dl-5-1 5.1 -Avai labi Ii ty (***)· · ·· ··Dl-5-1 5.2 -Distillate Price (***)··· ···Dl-5-1 6 -REFERENCES • • . ..•.··• • •• ••·• • ••·•Dl-6-1 3.1 -Cook Inlet Gas Prices (***)••••• 3.2 -Regulatory Constraints on the Availability of Na tural Gas (***)• . . • • • • • • • . • • • 3.3 -Physical Constraints on the Availability of Cook Inlet Natural Gas Supply (***)• • • • • 3.4 -North Slope Natural Gas (***)•••. Dl-4-1 Dl-3-10 Dl-3-l Dl-3-12 Dl-3-20 Dl-4-1 Dl-4-3 Dl-4-4 Dl-4-10 ·. ·..........-.. -Resources and Reserves (***) -Demand and Supply (***)• . • • • • -Present and Potential Alaska Coal Prices (***) -Alaska Coal Prices Summarized (***). 4.1 4.2 4.3 4.4 4 -COAL (***)....'... ! I ( l I -I I 851014 xi SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 1 GENERAL DESCRIPTION OF THE LOCALE ................... 1 -GENERAL DESCRIPTION (*)• • • .... ..... ..... I -] I \ J \ I E-l-l-l E-I-3":'1 E-1-2-1 Page No. • • • • • •E-l-l-l • .E-I-I-2 ·. · ... ••••• • . .. .. . •• 1.1 -General Setting (**) 1.2 -Susitna Basin (*)•• Title 2 -REFERENCES 3 -GLOSSARY 851014 xii I I -I I I 1 ( I \ SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 2 WATER USE AND QUALITY . . .. Page No. E-2-2-l E-2-1-1 ·. · . ... • • e _. ... .. .. .. . . .. 1 -INTRODUCTION (**j • • • • • Title 2 -BASELINE DESCRIPTION (**) 2.1 -Susitna River Morphology (**)•. 2.2 -Susitna River Water Quantity (**)•••...•• 2.3 -Susitna River Water Quality (**)••••••••• 2.4 -Baseline Ground Wa~er Conditions (**)•• 2.5 -Existing Lakes,Reservoirs,and Streams (**)•• 2.6 -Existing Instream Flow Uses (0)••••• 2.7 -Access Plan (**)•••••• 2.8 -Transmission Corridor (**). E-2-2-3 E-2-2-12 E-2-2-19 E-2-2-46 E-2-2-49 E-2-2-50 E-2..,.2-63 E-2-2-64 3 -OPERATIONAL FLOW REGIME SELECTION (***)•• • ...·.E-2-3-1 3.1 -Project Reservoir Characteristics (***) 3.2 -Reservoir Operation Modeling (***)••• 3.3 -Development of Alternative Environmental Flow C~ses (***)••...••••••..••• 3.4 -Detailed Discussion of Flow Cases (***). 3.5 -Comparison of Alternative Flow Regimes (***). 3.6 -Other Constraints on Project Operation (***) 3.7 -Power and Energy Production (***)•••••• E-2-3-l E-2-3-2 E-2-3-6 E-2-3-17 E-2-3-37 E-2-3-43 E-2-3-53 4 -PROJECT IMPACT ON WATER QUALITY AND QUANTITY (**)...E-2-4-1 6 -MITIGATION,ENHANCEMENT,AND PROTECTIVE MEASURES (**)• 6.1 -Introduction (*).•...••.•••.•••. 6.2 -Mitigation -Watana Stage I -Construction (**)• 6.3 -Mitigation -Watana Stage I -Impoundment (**). 4.1 -Watana Development (**)...••• 4.2 -Devil Canyon Development (**)•.•• 4.3 -Watana Stage III Development (***). 4.4 -Access Plan (**)••••.• 5 -AGENCY CONCERNS AND RECOMMENDATIONS (**)E-2-5-1 E-2-6-1 E-2-4-7 E-2-4-110 E-2-4-160 E-2-4-211 E-2-6-1 E-2-6-1 E-2-6-5 ·... . .. ..... xiii851014 j I j 1 ) j .. . SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 2 WATER USE AND QUALITY Tit:;le 6.4 -Watana Stage I Operation (**). 6.5 -Mitigation -Devil Canyon Stage II - Construction (**)• • • • 6.6 -Mitigation -Devil Canyon Stage II - Impoundment (**)••••• • 6.7 -Mitigation -Devil Canyon/Watana Operation (**) 6.8 -Mitigation -Watana Stage III - Construction (***)••••••••••••••. 6.9 -Mitigation -Watana Stage III - Impoundment/Construction (***)••• • 6.10 -Mitigation -Stage III Operation (***)••• 6.11 -Access Road and Transmission Lines (***)•••• Page No. E-2-6-7 E-2-6-13 E-2-6-13 E-2-6-13 E-2-6-15 E-2-6-16 E-2-6-16 E-2-6-18 J j 1 7 -REFERENCES • • • • • •_.• • e • • • • • • • • • • • •E-2-7-1 8 -GLOSSARY 851014 ....................... xiv E-2-8-1 I l I -1 I SUMMARY TABLE OF CONTENTS (cont'd) J I EXHIBIT E -CHAPTER 3 FISH,WILDLIFE,AND BOTANICAL RESOURCES Title Page No. I -INTRODUCTION (-0)E-3-1-1 1.1 -Baseline Descriptions (0) 1.2 -Impact Assessments·(*)•••• 1.3 -Mitigation Plans (*) 2 -FISH RESOURCES OF THE SUSITNA RIVER.DRAINAGE-(**)... E-3-1-1 E-3-1-1 E-3-1-3 E-3-2-1 2.1 -Overview of the Resources (**)••••• 2.2 -Species Biology and Habitat Utilization in the Susitna River Drainage (*)•••• 2.3 -Anticipated Impacts To Aquatic Habitat (**) 2.4 -Mitigation Issues and Mitigating Measures (**) 2.5 -Aquatic Studies Program (*)••••• 2.6 -Monitoring Studies (**)•••••••.. 2.7 -Cost of Mitigation (***)•••••••• 2.8 -Agency Consultation on Fisheries Mitigation Measures (**)••• •• 3.1 Introduction (*)•.•••..••. 3.2 -Baseline Description (**)• ••.• 3.3 -Impacts (**)•••• 3.4 -Mitigation Plan (**) ............ ... 5.1 -Introduction (***) 5.2 -Existing Conditions (***)• • • • • • • 5.3 -Expected Air Pollutant Emissions (***). 5.4 -Predicted Air Quality Impacts (***)•• E-3-3-1 E-3-2-1 E-3-4-1 E-3-2-14 E-3-2-104 E-3-2-244 E-3-2-279 E-3-2-280 E-3-2-303 E-3-4-1 E-3-4-3 E-3-4-110 E-3-4-248 E-3-3-1 E-3-3-6 E-3-3-34 E-3-3-63 E-3-2-304 E-3-5-1 E-3-5-1 E-3-5-1 E-3-5-2 E-3-5-3 • • ... •• .. . • •• ••• .. ..... . xv ......••(**)•••• 4.1 -Introduction (*)••.• 4.2 -Baseline Description (**) 4.3 -Impacts (*).. 4.4 -Mitigation Plan (**) 3 -BOTANICAL RESOURCES (**) 5 -AIR QUALITY/METEOR.OLOGY (***)• 851014 4 -WILDLIFE I f I I I I 1 1 i j SUMMARY TABLE OF CONTENTS (cant:I d) Title EXHIBIT E -CHAPTER 3 FISH,WILDLIFE,AND BOTANICAL RESOURCES 5.5 -Regulatory Agency Consultations (***)• 6 -REFERENCE •• • .... . ... ........ Page No. E-3-5-3 E-3-6-1 j j \ 7 -GLOSSARY .............. ..... ..E-3-7-1 APPENDICES E1.3 E2.3 E3.3 E4.3 E5e3 E6.3 E7.3 Ea.3 E9.3 E10.3 Ell.3 851014 FISH AND WILDLIFE MITIGATION POLICY ENVIRONMENTAL GUIDELINES MEMORANDUM (THIS APPENDIX HAS BEEN DELETED) PLANT SPECIES IDENTIFIED IN SUMMERS OF 1980 AND 1981 IN THE UPPER AND MIDDLE SUSITNA RIVER BASIN,THE DOWNSTREAM FLOODPLAIN,AND THE INTERTIE PRELIMINARY LIST OF PLANT SPECIES IN THE INTERTIE AREA (THIS SECTION HAS BEEN DELETED AND ITS INFORMATION INCORPORATED INTO APPENDIX E3.3.) STATUS,HABITAT USE AND RELATIVE ABUNDANCE OF BIRD SPECIES IN THE MIDDLE SUSITNA BASIN STATUS AND RELATIVE ABUNDANCE OF BIRD SPECIES OBSERVED ON THE LOWER SUSITNA BASIN DURING GROUND SURVEYS.CONDUCTED JUNE 10 THE JUNE 20,1982 SCIENTIFIC NAMES OF MAMMAL SPECIES FOUND IN THE PROJECT AREA METHODS USED TO DETERMINE MOOSE BROWSE UTILIZATION AND CARRYING CAPACITY WITHIN THE MIDDLE SUSITNA BASIN EXPLANATION AND JUSTIFICATION OF ARTIFICIAL NEST MITIGATION (THIS SECTION HAS BEEN DELETED) PERSONAL COMMUNICATIONS (THIS SECTION HAS BEEN DELETED) EXISTING AIR QUALITY AND METEOROLOGICAL CONDITIONS xvi ~ I I I j ! \ J SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 4 HISTORIC AND ARCHEOLOGICAL RESOURCES 3.1 -Evaluation of Selected Sites Found: Prehistory and History of the Middle Susitna Region (**)• • • • • • • • • • • • • • • 3.2 -Impact on Historic and Archeological Sites (**). ....................... E-4-5-1 E-4-3-1 E-4-3-4 E-4-2-1 E-4-2-12 E-4-2-13 E-4-4-1 E-4-1-1 E-4-3-1 Page No. E-4-7-1 E-4-6-1 E-4-2-1 E-4.,.2-2 E-4-2-10 E-4:-1-4 E-4-1-4 E-4-4-1 E-4-4-2 • • ·. ·. • •• • •• ·. · . • • • · . . ••• ·.. ·. •• •• •• .. .... .. .. . .. ... ••• •••• •• •••••• xvii ....... ............... 1.1 -Program Objectives (**)• 1.2 -Program Specifics (**) 2.1 -The Study Area (**)•••••• 2.2 -Methods -Archeology and History (**) 2.3 -Methods -Geoarcheology (**) 2.4 -Known Archeological and Historic Sites in the Project Area (**) 2.5 -Geoarcheology (**)••••••• 4.1 -Mitigation Policy and Approach (**) 4.2 -Mitigation Plan (**).•••. Title 1 -INTRODUCTION AND SUMMARY (**)• 3 -EVALUATION OF AND IMPACT ON HISTORICAL AND ARCHEOLOGICAL SITES (**)••••• 2 -BASELINE DESCRIPTION (**)• 5 -AGENCY CONSULTATION (**) 851014 7 -GLOSSARY 4 -MITIGATION OF IMPACT ON HISTORIC AND ARCHEOLOGICAL SITES(**)• • • • • • • 6 -REFERENCES 1 I I -/ I I I I j I -( l i j I I 1 ! I SUMMARY TABLE OF CONTENTS (cont'd)~I EXHIBIT E -CHAPTER 5 SOCIOECONOMIC IMPACTS Title Page No. 2 .00 ....... 1 -INTRODUCTION (**)0 0 0 • • BASELINE DESCRIPTION (**)0 o 0 o • • • 0 e • • • •••• • E-5-l-1 E-5-2-1 2.1 -Identification of Socioeconomic Impact Areas (**)••0 ••••••••0 • • • •E-5-2-1 2.2 -Description of Employment,Population,Personal Income and Other Trends in the Impact Areas (**)E-5-2-1 3 -EVALUATION OF THE IMPACT OF THE PROJECT (**).....E-5-3-1 I l I -j E-5-3-35 E-5-3-2 E-5-3-39 E-5-3-32 E-5-3-49 E-S-4-1 E-5-3-65 E-5-3-59 E-S-4-2 E-S-4-1 E-5-4-1 E-5-4-2 ·. .. · . .. ·... .. ... .............. 3.1 -Impact of In-migration of People on Governmental Fad li ties and Services (**)••.••••••• 3.2 -On-site Worker Requirements and Payroll, by Year and Month (**)••••••••• 3.3 -Residency and Movement of Project Construction Personnel (**)• • • • • • • • • • 3.4 -Adequacy of Available Housing in Impact Areas (***)0... 3.5 -Displacement and Influences on Residences and Businesses (**)• • . • • • • • • • • • • 3.6 -Fiscal Impact Analysis:Evaluation of Incremental Local Government Expenditures and Revenues (**)• • • • • • • • • • • • • 3.7 -Local and Regional Impacts on Resource User Groups (**)• 4.1 -Introduction (**)• 4.2 -Background and Approach (**) 4.3 -Attitudes Toward Changes (This section deleted) 4.4 -Mitigation Objectives and Measures (**) 4 -MITIGATION (**)0 0 851014 xviii Page No. E-6-6-1 E-5-5-1 E-5-5-l E-5-5-1 E-5-5-2 E-5-5-2 .. .... X1X ............ .......... SUMMARY TABLE OF CONTENTS (cant'd) EXHIBIT E -CHAPTER 5 SOCIOECONOMIC IMPACTS 5.1 -Alaska Department of Natural Resources (DNR)(**) 5.2 -Alaska Department of Fish and Game (ADF&G)(*) 5.3 -u.s.Fish and Wildlife Service (FWS)(*) 5.4 -Summary of Agencies'Suggestions for Further Studies that Relate to Mitigation (**) Title 5 -MITIGATION MEASURES RECOMMENDED BY AGENCIES(**) 6 -REFERENCES 851014 1 j j j ] l j ! I j i j j j I I 1 j I SUMMARY TABLE OF CONTENTS (eont'd) EXHIBIT E -CHAPTER 6 GEOLOGICAL AND SOIL RESOURCES Title 1 -INTRODUCTION (**) Page No. E-6-1-1 J j 2 -BASELINE DESCRIPTION (*)•9 ·•· · · • • 9 ·• • •·E-6-2-1 2.1 -Regional Geology (*)· ·· ··E-6-2-l 2.2 -Quarternary Geology (*)····E-6-2-2 2.3 -Mineral Resources·(0)···· · ·E-6-2-3 2.4 -Seismic Geology (*)· ·· ··· ··E-6-2-4 2.5 -Watana Damsite (**)· · · ··········E-6-2-11 2.6 -Devil Canyon Damsite (0)•···· · · · ·E-6-2-l7 2.7 -Reservoir Geology (*)··· · · · · · · · E-6-2-23 3 -IMPACTS (*)·•••• • ••• ••• • • • ••• •·••E-6-3-1 3.1 -Reservoir-Induced Seismici ty (RIS)(*)· · •E-6-3-1 3.2 -Seepage (*)· · · ·..· · ·· · ·· · · ·E-6-3-4 3.3 -Reservoir Slope Failures (**)·•·· · E-6-3:-4 3.4 -Permafrost Thaw (*)······ · ·· · E-6-3-11 3.5 -Seismically-Induced Failure (*)··· · E-6-3-11 3.6 -Reservoir Freeboard for Wind Waves (**)··E-6-3-11 3.7 -Development of Borrow Sites and Quarries (**)··E-6-3-12 4 -MITIGATION (**)·•·• •·• • ••• ••• •·• •••E-6-4-1 4.1 -Impacts and Hazards (0)····E-6-4-1 4.2 -Reservoir-Induced Seismicity (0)··· · · · E-6-4-1 4.3 -Seepage (**)•· · · · · · ····•E-6-4-2 4.4 -Reservoir Slope Failures (**)·E-6-4-2 4.5 -Permafrost Thaw (**)·· · •· · ·E-6-4-3 4.6 -Seismically-Induced Failure (*)··· · ·····E-6-4-3 4.7 -Geologic Hazards (*)···E-6-4-4 4.8 -Borrow and Quarry Sites (*)· ···· · ···E-6-4-4 5 -REFERENCES •·• ••• ••·• •·• •·• • • • ••·E-6-5-1 6 -GLOSSARY • • • • 9 • • ••• • • • • • • • • • ••••E-6-6-1 I ~ I j ] 1 I -1 j 1 , I 851014 xx . SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 7 RECREATIONAL RESOURCES • 1.1 -Purpose (**)•.•••. 1.2 -Relationships to Other Reports (*) 1.3 -Study Approach and Methodology (**) 1.4 -Project Description (**)•.••. Title 1 -INTRODUCTION (**)•• • ..••••..·... ... ·. Page No. E-7-I-1 E-7-I-1 E-7-I-l E-7-I-1 E-7-1-3 2 -DESCRIPTION OF EXISTING AND FUTURE RECREATION WITHOUT THE SUSITNA PROJECT (**)••••••••...E-7-2-1 2.1 -Statewide and Regional Setting (**)• 2.2 -Susitna River Basin (**)••••••· . E-7-2-1 E-7-2-8 3.1 -Direct Impacts of Project Features (**)• 3.2 -Project Recreational Demand Assessment ••• (Moved to Appendix E4.7) .'.... ............ ............. .. E-7-3-1 E-7-4-1 E-7-3-1 E-7-3-12 E-7-4-1 E-7-4-2 E-7-4-2 E-7-5-1 E-7-5-4 E-7-4-3 E-7-4-12 E-7-4-13 E-·7-5-1 E-7-5-2 E-7-5-4 E-7-6-1 •• ·. • • ·. . . ·. .. • ••• • ·. · . -Characteristics of the Project Design and Operation (***)• • . • • • • • . • . • • -Characteristics of the Study Area (***)~ -Recreation Use Patterns and Demand (***) -Agency,Landowner and Applicant Plans and Policies (***)• . • • • • • • • • • • • -Public Interest (***)• • • • • • • • • • -Mitigation of Recreation Use Impacts (***) 5.1 -Recreation Plan Management Concept (***) 5.2 -Recreation Plan Guidelines (***) 5.3 -Recreational Opportunity Evaluation. (Moved to Appendix E3.7.3) 5.4 -The Recreation Plan (**)••• 4.1 4.2 4.3 4.4 4.5 4.6 3 -PROJECT IMPACTS ON EXISTING RECREATION (**) 5 -RECREATION PLAN (**) 4 -FACTORS INFLUENCING THE RECREATION PLAN (**) 6 -PLAN IMPLEMENTATION (**) I ) -I l j I I I 1 I 851014 xxi SUMMARY TABLE OF CONTENTS (cont'd) Title 7 -COSTS FOR CONSTRUCTION AND OPERATION OF THE PROPOSED RECREATION FACILITIES (**)•••••••••••••• 7.1 -Construction (**)••• 7.2 -Operations'and Maintenance (**) 7.3 -Monitoring (***)•••••••••• 1 I J J 1 I ~ I I I I I ~I Page No. E-7-9-1 E-7-7-1 E-7-8-1 E-7-8-1 E-7-8-1 E-7-8-1 E-7-8-2 E-7-10-1 E-7-7-1 E-7-7-1 E-7-7-2 E-7-6-1 E-7-6-1 E-7-6-2 E-7-6-3 ............. .. . . ................... ATTRACTIVE FEATURES -'INVENTORY DATA DATA ON REGIONAL RECREATION FACILITIES .............. ........ EXHIBIT E -CHAPTER 7 RECREATIONAL RESOURCES 6•1 -Pha sing (**)••••••••••.••• 6.2 -Detailed Recreation Design (***)•••• 6.3 -Operation and Maintenance (***)•• 6.4 -Monitoring (**)•••.••••••••• 8.1 -Agencies and Persons Consulted (**)• 8.2 -Agency Comments (**)•••••••• 8.3 -Native Corporation Comments (***)•• 8.4 -Consul tation Meetings (***)•••• • • • • • E2.7 El.7 10 -GLOSSARY APPENDICES 8 -AGENCY COORDINATION (**) 9 -REFERENCES E3.7 RECREATION SITE INVENTORY AND OPPORTUNITY EVALUATION E4.7 PROJECT RECREATIONAL DEMAND ASSESSMENT E5.7 EXAMPLES OF TYPICAL RECREATION FACILITY DESIGN STANDARDS FOR THE SUSITNA PROJECT E6.7 PHOTOGRAPHS OF SITES WITHIN THE PROJECT RECREATION STUDY AREA 851014 xxii 1.1 -Purpose (*).· ···· · · ··· · · ·E-8-1-1 1.2 -Relationship to Other Analyses (*)E-8-1-1 1.3-Environmental Setting (**)· · · ·E-8-1-1 2 -PROCEDURE (*)• • ••· · • •·•·•·• • •· · • • .E-8-2-1 3 -STUDY OBJECTIVES (*)• • ••• •·•·• •• • E-8-3-1 4 -PROJECT FACILITIES (*)· · ••· · · •••• •·•• • E-8-4-1 SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 8 AESTHETIC RESOURCES 4.1 -Watana Project Area (*)• ••••••••• 4.2 -Devil Canyon Project Area (*)•••. 4.3 -Watana Stage III Project Area (***) 4.4 -Denali Highway to Watana Dam Access Road (*) 4.5 -Watana Dam to Devil Canyon Dam Access Road (*) 4.6 -Transmission Lines (*).•••. 4.7 -Intertie ••••••.• . • • • • . ••.• (This section deleted) 4.8 -Recreation Facilities and Features (*) E-8-1-1 E-8-4-2 Page No. E-8-5-1 E-8-7-1 E-8-6-1 E-8-4-1 E-8-4-1 E-8-4-1 E-8-4-1 E-8-4-2 E-8-4-2 E-8-4-2 E-8-5-1 E-8-5-1 E-8-6-1 E-8-6-1 E-8-7-1 E-8-7-1 E-8-7-2 ·. · . . . ·.. ·. . . • •• • • ·...... ·.. . . ·.••·. ·.. ·.... xxiii ·....... ·.. ·.. .. .................... 5.1 -Landscape Character Types (*) 5.2 -Notable Natural Features (**) 7.1 -Aesthetic Value Rating (*) 7.2 -Absorption Capability (*) 7.3 -composite Ratings (**) 6.1 -Viewers (***) 6.2 -Visibility (***) 1 -INTRODUCTION (**)• Title 5 -EXISTING LANDSCAPE (**)• 6 -VIEWS (**) 851014 . 7 -AESTHETIC EVALUATION RATINGS (**) I 1 J -, I I I I I I -I I j I I I 1 I ) SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 8 AESTHETIC RESOURCES J Title Page No.J 8 -AESTHETIC IMPACTS (**)•e-• • • • • • • • • • • • • •E-8-8-l 8.1 -Mitigation Planning of Incompatible Aesthetic Impacts (Now addressed in Section 9)E-8-8-1 8.2 -Watana Stage I (***)E-8-8-2 8.3 -Devil Canyon Stage II (***)· · --· · E-8-8-3 8.4 -Watana Stage III (***)··· ····.·.E-8-8-4 8.5 -Access Routes (***).······· ·· · ·E-8-8-5 8.6 -Transmission Facilities (***)· ··· · ·E-8-8-6 10 -AESTHETIC IMPACT EVALUATION OF THE INTERTIE (This Section Delected) 11.1 -Agencies and Persons Consulted (**) 11.2 -Agency Comments (**)•••• 9.1 -Mitigation Feasibility (**) 9.2 -Mitigation Plan (***)•••. 9.3 -Mitigation Costs (**)•••. 9.4 -Mitigation Monitoring (***) I ~ I ) I I I l E-8-9-1 E-8-l0-l E-8-9-1 E-8-9-2 E-8-9-l1 E-8-9-12 E-8-12-l E-8-11-l E-8-13-1 E-8-11-l E-8-11-1 ·. •• . . . • e ••• • •• ·.... ·..... •• • • ••• • ••• ·.. ••• •• • • • • •• • ••• •• ·.... .. . ... ...... ••••• 9 -MITIGATION (**)• • • • • • • 11 -AGENCY COORDINATION (**)• 13 -GLOSSARY. 12 -REFERENCES • APPENDICES E1.8 EXCEPTIONAL NArURAL FEATURES E2.8 SITE PHOTOS WITH SIMULATIONS OF PROJECT FACILITIES E3.8 PHOTOS OF PROPOSED PROJECT FACILITIES SITES E4.8 EXAMPLES OF EXISTING AESTHETIC IMPACTS 851014 xxiv APPENDICES (cont'd) I 1 :J 1 1 Title SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 8 AESTHETIC RESOURCES Page No. E5.8 I E6.8 E7.8 I E8.8 1 E9.8 J J I I 851014 EXAMPLES OF RESERVOIR EDGE CONDITIONS SIMILAR TO THOSE ANTICIPATED AT WATANA AND DEVIL CANYON DAMS PROJECT FEATURES IMPACTS AND CHARTS GENERAL AESTHETIC MITIGATION MEASURES APPLICABLE TO THE PROPOSED PROJECT LANDSCAPE CHARACTER TYPES OF THE PROJECT AREA AESTHETIC VALUE AND ABSORPTION CAPABILITY RATINGS xxv SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 9 LAND USE Title 1 -INTRODUCTION (***)• • • • • • • • • • • 2 -HISTORICAL AND PRESENT LAND USE (***) ...• ••• Page No. E-9-1-1 E-9-2-1 2.1 -Historical Land Use (***) 2.2 -Present Land Use (***)••0 ••.. . E-9-2-1 E-9-2-1 3 -LAND MANAGEMENT PLANNING IN THE PROJECT ~(***)• • • • • • • • . • • • • • •• • •••••E-9-3-1 , -I 4 -IMPACTS ON LAND USE WITH AND WITHOUT THE PROJECT (***)••••••••••••••••••••E-9-4-1 5 -MITIGATION (***)•••••....•• •• E-9-6-1 E-9-5-1 • • • .. • ••• ...•••....•• ••• • • 6 -REFERENCES 851014 xxvi "j j j 1 j I i SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 10 ALTERNATIVE LOCATIONS,DESIGNS,AND ENERGY SOURCES 1 -ALTERNATIVE HYDROELECTRIC SITES (*)• • • • • • • • ... -1 I Title 1.1 1.2 1.3 1.4 -Non-Susitna Hydroelectric Alternatives (*) -Assessment of Selected Alternative Hydroelectric Sites (***)• • • • • . -Middle Susitna Basin Hydroelectric Alternatives (0).•• • • • • • • • • • • • • -Overall Comparison of Non-Susitna Hydroelectric Alternatives to the Proposed Susitna Project (***) .. Page No. E-10-l-1 E-10-l-1 E-10-1-2 E-I0-1-17 E-1O-1-32 2 -ALTERNATIVE FACILITY DESIGNS (*)...........E-10-2-1 2.1 -Watana Facility Design Alternatives (*) 2.2 -Devil Canyon Facility Design Alternatives 2.3 -Access Alternatives (0)• • • ••• 2.4 -Transmission Alternatives (0)•• 2.5 -Borrow Site Alternatives (**) (0)· . E-1O-2-1 E-10-2-3 E-10-2-4 E-1O-2-24 E-10-2-53 3 -OPERATIONAL FLOW REGIME SELECTION (***)•• • •·...E-10-3-1 -\ I \ 1 i i 3.1 -Project Reservoir Characteristics (***) 3.2 -Reservoir Operation Modeling (***)..•. 3.3 -Development of Alternative Environmental Flow Cases (***)•••••••••.•••• 3.4 -Detailed Discussion of Flow Cases (***)• • • • • 3.5 -Comparison of Alternative Flow Regimes (***) 3.6 -Other Constraints on Project Operation (***) 3.7 -Power and Energy Production (***)••• • E-I0-3-1 E-1O-3-2 E-1O-3-6 E-10-3-l7 E-10-3-38 E-10-3-43 E-1O-3-53 4 -ALTERNATIVE ELECTRICAL ENERGY SOURCES (***)••·...E-10-4-1 I. V' 4.1 -Coal-Fired Generation Alternatives (***) 4.2 -Thermal Alternatives Other Than Coal (***) 4.3 -Tidal Power Alternatives (***)•••••• 4.4 Nuclear Steam Electric Generation (***)• • • 4.5 -Biomass Power Alternatives (***).••• 4.6 -Geothermal Power Alternatives (***)•• E-lO-4-1 E-10-4-27 E-10-4-39 E-lO-4-41 E-lO-4-42 E-lO-4-42 851014 xxvii SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 10 ALTERNATIVE LOCATIONS.DESIGNS.AND ENERGY SOURCES 5 -ENVIRONMENTAL CONSEQUENCES OF LICENSE DENIAL (***) Title 4.7 -Wind Conv~rsion Alternatives (***) 4.8 -Solar Energy Alternatives (***) 4.9 -Conservation Alternatives (***).• ... .. Page No. E-IO-4-43 E-lO-4-44 E-lO-4-44 E-lO-5-l J J ,I I 6 -REFERENCES 7 -GLOSSARY ........... ............ ....... . ...... •••• .... E-lO-6-l E-IO-7-1 -I,! I I I -1 ) 851014 xxviii ,, J -I I SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT E -CHAPTER 11 AGENCY CONSULTATION Title Page,No. =I 1 -ACTIVITIES PRIOR TO FILING THE INITIAL APPLICATION (1980-February 1983)(***)... .... ..E-ll-l-l 2 -ADDITIONAL FORMAL AGENCY AND PUBLIC CONSULTATION (***)• • • • • • • • • •........ . E-1l-2-1 \ I I \ -\ 'I l 2.1 -Technical Workshops (***)•••••• 2.2 -Ongoing Consultation (***)••••. 2.3 -Further Comments and Consultation (***) E-1l-2-1 E-1l-2-1 E-1l-2-2 851014 xxix SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT F SUPPORTING DESIGN REPORT (PRELIMINARY) Title Page No. \ ----J 1 -PROJECT DATA (***).•• •••••• •• • • ••• • • • F-1-1 2 -PROJECT DESIGN DATA (**)·..............F-2-1 2.1 -Topographical Data (0)····F-2-1 2.2 -Hydrological Data (**)···· · · · ····F-2-1 2.3 -Meteorological Data (*)·· ······F-2-1 -I2.4 -Reservoir Data (0)·········F-2-1 2.5 -Tailwater Elevations (0)· · ··F-2-1 2.6 -Design Floods (**)·· ······ · ···F-2-2 3 -CIVIL DESIGN DATA (*)•• •·• ••• • • •·•••·•F-3-1 3.1 -Governing Codes and Standards (0)··F-3-1 3.2 -Design Loads (**)······•·F-3-1 3.3 -Stability (*)···· · · · ··· · · ·· · · F-3-6 3.4 -Material Properties (0)· ······•·F-3-9 4 GEOTECHNICAL DESIGN DATA (**)·•·••·•·• •••·F-4-1 4.1 -Watana (**).· ·····•··F-4-1 4.2 -Devil Canyon (**)·· ···F-4-10 5 -HYDRAULIC DESIGN DATA (**)•••• •••·• ••••·F-5-1 5.1 -River Flows (**)··· · ···· · ···F-5-1 5.2 -Design Flows (**)····F-5-1 ~ 5.3 -Reservoir Levels (**)· · ····· · · ·F-5-l I 5.4 -Reservoir Operating Rule (**)·•·F-5-2 5.5 -Reservoir Data (**)··•····F-5-2 5.6 Wind Effect (**)·· ·· · ···F-5-3 5.7 -Criteria (***)········· · F-5-3 6 -EQUIPMENT DESIGN CODES AND STANDARDS (**)• • 6.1 -Design Codes and Standards (*)••• 6.2 -General Criteria (*)•••••• ·.·..F-6-1 F-6-1 F-6-2 851014 xxx I 1 J SUMMARY TABLE OF CONTENTS (cont'd) EXHIBIT F SUPPORTING DESIGN REPORT (PRELIMINARY) _I -I I Title Page No. F-7-1 F-6-4 F-6-6 F-6-6 F-6-8 F-6-9 F-6-12 . . . ....... ............... THIS APPENDIX DELETED 6.3 -Diversion -Structures and Emergency Release Facilities (*)•••••.••.••• 6.4 -Spillway (**)• ••••.'•••• 6.5 -Outlet Faci li ties (*). • • . 6.6 -Power Intake (*).•••• 6.7 -Powerhouse (**)••• 6.8 -Tailrace Tunnels (**) F1 APPENDICES 7 -REFERENCES1 I F2 WATANA AND DEVIL CANYON EMBANKMENT STABILITY ANALYSES F3 SUMMARY AND PMF AND SPILLWAY DESIGN FLOOD ANALYSES \ 1 i 1\ I 851014 xxxi J ~\-/ TABLE OF CONTENTS I ( =I SUSITNA HYDROELECTRIC PROJECT LICENSE APPLICATION EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS Title 1 -PROJECT STRUCTURES -WATANA STAGE I (**)• 1.1 -General Arrangement (**) 1.2 -Dam Embankment (**) Page No. A-1-2 A-1-2 A-1-4 1.2.1. 1.2.2 - 1.2.3 - 1.2.4 - Typical Cross Section (**). Crest Details and Freeboard (**) Grouting and Pressure Relief System (**) Instrumentation (**). . . . . A-1-4 A-1-5 A-1-5 A-1-6 1.3 -Diversion (**)....A-1-6 1.3.1 1.3.2 1.3.3 1.3.4 -Tu nne 1s (**)• • • • Cofferdams (**)..... -Tunnel Portals and Gate Structures (**) -Final Closure and Reservoir Filling (**) A-1-6 A-1-7 A-I-7 A-I-8 1.4 -Emergency Release Facilities (**) 1.5 -Outlet Facilities (**). A-1-9 A-I-10 I I 1.5.1 -Approach Channel and Intake (**)A-I-10· · · ··1.5.2 -Intake Gates and Trashracks (**)·· · · · A-l-lO -I 1.5.3 -Shaft and Tunnel (**).··· · A-l-11 1.5.4 -Discharge Structure (**)· · · · A-1-11 1.5.5 -Fixed-Cone Discharge Valves (**)A-1-12 1.5.6 -Ri ng Fo llower Gates (**)· ·· · A-1-12 1.5.7-Discharge Area (**)· · · · A-l-12 1.6-Spillway (**). . . . .· · · · · · · ··A-l-13 1.6.1 -Approach Channel and Control Structure (**). .... 1.6.2 Spillway Gates and Stoplogs (**) 1.6.3 -Spillway Chute (**). 1.6.4 -Flip Bucket (**). 1.7 -This section deleted •.• A-1-13 A-l-I4 A-l-14 A-l-14 A-I-IS 851011 1. \ cd \,I I -) ) j I j I I -I J - I I I EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont'd) Title Page No. \ .---l 1.8 -Power Intake (**) 1.8.1 -Intake Structure (**) 1.8.2 -Approach Channel (**). 1.8.3 -Mechanical Arrangement (**) (a)Ice Boom (**). . (b)Trashracks (**). (c)Intake Shutters (**) (d)Intake Service Crane (**). (e)Intake Bulkhead Gates (**)..... (0 Intake Gates (**).. 1.9 -Power Tunnels and Penstocks (**). 1.9.1 -Steel Liner (**). 1.9.2 -Concrete Lining (**). . . . . . 1.9.3 -Grouting and Pressure Relief System (**) 1.10 -Powerhouse (**) 1.10.1 -Access Tunnels and Shafts (**) 1.10.2 -Powerhouse Cavern (**) 1.10.3 -Transformer Gallery (**) 1.10.4 -Surge Chamber (**) 1.10.5 -Grouting and Pressure Relief System (**). . . . . 1.10.6 -SF6 Gas Insulated Bus Shaft (**) 1.10.7 -Draft Tube Tunnels (**)•... 1.11 -Tailrace (**) 1.12 -Main Access Plan (**) A-1-15 A-l-I5 A-1-16 A-I-16 A-1-16 A-1-16 A-1-16 A-1-17 A-l-17 A-l-17 A-l-I8 A-l-I8 A-I-18 A-I-19 A-I-19 A-I-19 A-I-20 A-I-20 A-I-2I A-1-22 A-I-22 A-I-22 A-I-22 A-I-23 1.12.1 -Access Objectives (*) 1.12.2 -Access Plan Selection 1.12.3 -Description of Access 1.12.4 -Right-of-Way (**)•. 1.12.5 -Construction Schedule 1.13 -Site Facilities (**) (**). . . . . . . Plan (**) A-I-23 A-I-23 A-I-23 A-1-24 A-1-25 A-I-25 1.13.1 -General (**).... 1.13.2 -Temporary Camp and Village (**) 851011 A-1-25 A-I-26 ! I J 1 -\ i J EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont I d) Title Page No. 1.13.3- 1.13.4 - 1.13.5 - (a)Site Preparation (**) 1b)Facilities (**).... Permanent Town (**). . . . . . Site Power and Util ities (**). ... (a)Power (**).... (b)Water (**).•.. (c)Wastewater (**) Contractors'Area (**).•.. A-1-26 A-1-27 A-1-27 A-1-27 A-l-27 A-1-28 A-1-28 A-1-29 r I ) 1.14 -Relict Channel (***) 1.14.1 -Surface Flows (**) 1.14.2 -Subsurface Flows (**)..•. 1.14.3 -Permafrost (**). 1.14.4 -Liquefaction (***). 1.14.5 -Remedial Work Influence on Construction Schedules (***). . . . . . . . 1.14.6 -Relict Channel Treatment (***) 2 -RESERVOIR DATA -WATANA STAGE I (**)• 3 -TURBINES AND GENERATORS -WATANA STAGE I (**) 3.1 -Unit Capacity (**) 3.2 -Turbines (***). 3.3 -Generators (**) 3.3.1 -Type and Rating (**) 3.3.2 -Unit Dimensions (**).... 3.3.3 -Generator Excitation System (**) 3.4 -Governor System (0) 4 -APPURTENANT MECHANICAL AND ELECTRICAL EQUIPMENT - WATANA STAGE I (**)•••••••••• 4.1 -Miscellaneous Mechanical Equipment (**) 4.1.1 -Powerhouse Cranes (*) 4.1.2 -Draft Tube Gates (**) A-1-29 A-1-29 A-1-29 A-1-30 A-1-30 A-l-30 A-1-31 A-2-1 A-3-1 A-3-1 A-3-1 A-3-1 A-3-1 A-3-2 A-3-2 A-3-3 A-4-1 A-4-1 A-4-1 A-4-1 851011 ~~~ ,I I ~ J \ I ,I -I f I ,I 4.2.8 - 4.2.9 - 4.2.10- 1 EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont'd) Title 4.1.3 -S~rge Chamber Gate Crane (*).... 4.1.4 Miscellaneous Cranes and Hoists (**) 4.1.5 -Elevators (**). . . . . ....... 4.1.6 -Power Plant Mechanical Service Systems (**). (a)Station Water Systems (0)• (b)Fire Protection System (**) (c)Compressed Air Systems (**). (d)Oil Storage and Handling (**). (e)Drainage and Dewatering Systems (**). (f)Heating,Ventilation,and Cooling (**). 4.1.7 -Surface Facilities Mechanical Service Systems (*)... . . . . . . 4.1.8 -Machine Shop Facilities (0)•••• 4.2 -Accessory Electrical Equipment (**) 4.2.1 -Transformers and HV Connections (**) 4.2.2 -Mai n Transformers (**). ..... 4.2.3 -Generator Isolated Phase Bus (**).... 4.2.4 -Generator Circuit Breakers (**) 4.2.5 -(section deleted) 4.2.6 -Control Systems (**). (a)General (*). (b)Unit Control System (*)••••• (c)Compu ter-A ided Contro 1 System (0) (d)Local Control and Relay Boards (0) (e)Load-Frequency Control (0) 4.2.7 -Station Service Auxiliary AC and DC Sys tems (**). . . . . . . . . . . . . . . (a)Auxiliary AC System (**).... (b)DC Auxiliary Station Service System (*) Grounding System (0) Lighting System (*) Communications (0)•• 4.3 -SF6 Gas-Insulated 345 kV Substation (GIS)(***) 5 -TRANSMISSION FACILITIES FOR WATANA STAGE I (**) 5.1 -Transmission Requirements (0) Page No. A-4-1 A-4-1 A-4-2 A-4-2 A-4-2 A-4-2 A-4-3 A-4-3 A-4-3 A-4-4 A-4-4 A-4-5 A-4-5 A-4-5 A-4-6 A-4-6 A-4-7 A-4-7 A-4-7 A-4-7 A-4-8 A-4-9 A-4-9 A-4-9 A-4-10 A-4-10 A-4-11 A-4-12 A-4-12 A-4-12 A-4-12 A-5-1 A-5-1 851011 1V i I I I I r J EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont I d) Title 5.2 -Descripti9n of Facilities (0) Page No. A-5-l 5.2.1 - 5.2.2 - 5.2.3 - 5.2.4 - 5.2.5 - 5.2.6 - 5.2.7- Corridor (0).•• Component s (0)• Right-ot-Way (0) Transmission Lines (0) switching and Stations (0) Cable Crossing (0) Dispatch Centers -Energy Management Centers and Communications (0)•••••• A-5-1 A-5-2 A-5-6 A-5-7 A-5-9 A-5-10 A-5-11 5.3 -Construction Staging (0)••••• 6 -PROJECT STRUCTURES -DEVIL CANYON STAGE II (**) 6.1 -General Arrangement (**) 6.2 -Arch Dam (**) 6.2.1 -Foundations (**) 6.2.2 -Arch Dam Geometry (*) 6.2.3 -Thrust Blocks (*) 6.3 -Saddle Dam (**) ·...A-5-11 A-6-l A-6-1 A-6-2 A-6-2 A-6-3 A-6-4 A-6-4 6.3.1 -Typical Cross Section (*)A-6-4 6.3.2 -Crest Detai Is and Freeboard (**)· · · ··A-6-5 6.3.3 -Grouting and Pressure Relief System (**)A-6-5 6.3.4 -Ins t rumentation (*)· · · · A-6-6 6.4 -Diversion (**). . . .A-6-6 6.4.1 -General (*)A-6-6 6.4.2 -Cofferdams (**). ..·.A-6-6 6.4.3 -Tunnel Porta Is and Gates (*)· · · · A-6-7 6.4.4 -Final Closure and Reservoir Filling (*)A-6-7 6.5 -Out let Facilities (**)· · · · A-6-8 6.5.1 Outlet (*). .····A-6-8 6.5.2 -Fixed-Cone Valves (*)·..·A-6-9 6.5.3 -Ri ng Fo llower Gates (*)· · · · A-6-9 6.5.4 -Trashracks (*)A-6-9 6.5.5 -Bu lkhead Gates (*). .· · · · · A-6-9 851011 v I ---l ! ----i -l J EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont 'd) Title 6.6 -Spillway {**) 6.6.1 -Approach Channel and Control Structure (*)..... 6.6.2 -Spillway Chute (**) 6.6.3 -Flip Bucket (**).... 6.6.4 -Plunge Pool (0) 6.7 -Emergency Spillway •. (This section deleted) 6.~-Power Facilities (*).. Page No. A-6-10 A-6-lO A-6-11 A-6-11 A-6-11 A-6-12 A-6-12 6.8.1 - 6.8.2 - 6.8.3 - 6.8.4 - Intake Intake Intake Intake Structure (*). Gates (*) Bu lkhead Ga te (*). . . . Gantry Crane (*) A-6-12 A-6-12 A-6-13 A-6-13 6.9 -Penstocks (**) 6.9.1 -Steel Liner (*) 6.9.2 -Concrete Liner (*) 6.9.3 -Grouting and Pressure Relief System (**). . . . . . . 6.10 -Powerhouse and Related Structures (**) 6.10.1 -Access Tunnels and Shafts 6.10.2 -Powerhouse Cavern (*).. 6.10.3 -Transformer Gallery (**) 6.10.4 -Surge Chamber (**) 6.10.5 -Draft Tube Tunnels (*) A-6-13 A-6-13 A-6-14 A-6-14 A-6-14 A-6-14 A-6-15 A-6-16 A-6-16 A-6-16 6.11 -Tailrace Tunnel (*)A-6-17 6.12 -Access Plan (**). .·· · · ·A-6-17 6.12.1 -Description of Access Plan (*)A-6-17 6.12.2 -Rai 1 Extension (*).··· · A-6-17 6.12.3 -Connecting Road (**)·· · ·A-6-18 6.12.4 -Constru ction Schedule (**)· · ...A-6-18 J 6.12.5 -Righ t-o f -Wa y (**)A-6-18 6.13 -Site Facilities (*)... .·.. .A-6-18 b51011 J I ----J i -I ) -I I i \ l EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont I d) Title Page No. 6.13.1 -_Temporary Camp and Village (**) 6.13.2 -Site Power and Utilities (**) (a)Power (**).... (b)Water (**). . . . (c)Wastewater (**) 6.13.3 -Contractors'Area (**) A-6-19 A-6-20 A-6-20 A-6-20 A-6-20 A-6-21 7 -DEVIL CANYON RESERVOIR STAGE II (*)... . .. ..A-7-1 8 -TURBINES AND GENERATORS -DEVIL CANYON STAGE II (**) 8.1 -Unit Capacity (**) 8.2 -Turbines (**) 8.3 -Generators (0) 8.4 -Governor System (0) 9 -APPURTENANT EQUIPMENT -DEVIL CANYON STAGE II (0) A-8-1 A-8-1 A-8-1 A-8-1 A-8-2 A-9-1 851011 Vl.l. J \ ----1 -! I \ , .I I 1 J EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont'd) Title (a)AC Auxiliary System (0) (b)DC Auxiliary Station Service System (0)•••••••••• 9.2.8 -Other Accessory Electrical Systems (0)•• 9.3 -Switchyard Structures and Equipment (0) 9.3.1 -Single Line Diagram (0)• ••••• 9.3.2 -Switchyard Structures and Layout (0) 10 -TRANSMISSION LINES -DEVIL CANYON STAGE 11 (**) 11 -PROJECT STRUCTURES -WATANA STAGE III (***) 11.1 -General Arrangement (***) 11.2 -Dam Embankment (***).•. Page No. A-9-5 A-9-6 A-9-6 A-9-6 A-9-6 A-9-6 A-10-1 A-ll-l A-ll-1 A-1l-3 11.2.1 -Typical Cross Section (***)· · · · · ·A-1l-3 11.2.2 -Crest Detai Is and Freeboard (***)A-11-3 11.2.3 -Grouting and Pressure Relief System (***)·······A-11-4 11.2.4 - 1 nst rumentat ion (***)A-1l-5 (a)Piezometers (***)· · · ·A-11-5 (b)Internal Vertical Movement Devices (***)· · · · · ··A-1l-5 (c)Internal Horizontal Movement Devices (***)· · · · · · · · · · ·A-1l-5 (d)Other Measuring Devices (***)A-1l-5 11.3 -Diversion (***). .· ···· · · · A-1l-5 11.4 -Emergency Release Facilities (***)A-1l-6 11.5 -Outlet Facilities (***)A-11-6 11.6 -Spi llway (***). ..· ·· · · · · · ·· · A-1l-7 851011 11.6.1 -Approach Channel and Control Structure (***) (a)Phase 1 (***). (b)Phase II (***) (c)Phase III (***) (d)Phase IV (***) viii A-1l-7 A-1l-7 A-1l-7 A-11-7 A-1l-8 J I ~ ( I I I 1 i \ ( EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont 'd) Title 11.6.2 -.Spillway Gates and Stop Logs (***). 11.6.3 -Spillway Chute (***). 11.6.4 -Flip Bucket (***). 11.6.5 -Access (***).... n.7 -Power Intake (***). . 11.7.1 -Intake Structures (***) 11.7.2 -Approach Channel (***) 11.7.3 -Mechanical Arrangement (***) (a)Ice Boom (***). . . . (b)Trashracks (***) (c)Intake Shutters (***)..... (d)Intake Service Crane (***) (e)Intake Bulkhead Gates (***). (f)Intake Gates (***) 11.8 -Power Tunnel and Penstocks (***) 11.8.1 -Steel Liner (***).....• 11.8.2 -Concrete Lining (***)•...• 11.8.3 -Grouting and Pressure Relief System (***). 11.9 -Powerhouse (***).• 11.9.1 -Access Tunnels and Sha its (***) 9 11.9.2 -Powerhouse Cavern (***)· ·· · ·11.9.3 -Transformer Gallery (***)·· · ·11.9.4 -Surge Chamber (***)..· · ···. 11.9.5 -Grouting and Pressure Relief System (***). . ....··11.9.6 -SF 6 Gas Insu lated Bus Shaft (***) 11.9.7 -Draft Tube Tunnels (***) 11.10 -Trailrace (***). 11.11 -Access Plan (***) 11.12 -Site Facilities (***) -( Page No. A-1l-8 A-11-8 A-1l-8 A-11-8 A-11-8 A-1l-8 A-11-9 A-11-9 A-11-9 A-11-9 A-11-9 A-II-I0 A-ll-IO A-ll-IO A-ll-ll A-ll-ll A-ll-11 A-11-ll A-ll-ll A-ll-ll A-1l-12 A-1l-12 A-ll-12 A-ll-13 A-ll-13 A-ll-13 A-1l-13 A-ll-13 A-ll-13 851011 lX ! j ( I 1 EXHIBIT A PROJECT DESCRIPTION TABLE OF CONTENTS (cont'd) Title Page No. 11.13 -Relict .Channel (***)A-1l-13 11.13.1 - 11.13.2 - 11.13.3 - 11.13.4 - 11.13.5 - 11.13.6 - Surface Flows (***) Subsurface Flows (***) Permafrost (***) Liquefaction (***) Remedial Work Influence on Construction Schedules (***)•••.. Relict Channel Treatment Summary (***) A-1l-14 A-11-14 A-1l-14 A-11-14 A-11-14 A-ll-i5 12 -RESERVOIR DATA -WATANA STAGE III (***)••••• 13 -TURBINES AND GENERATORS -WATANA STAGE III (***) 13.1 -Unit Capacity (***) 13.2 -Turbines (***)• 13.3 -Generators (***). 13.4 -Governor System (***) ...A-12-1 A-13-1 A-13-1 A-13-1 A-13-1 A-13-1 14 -APPURTENANT MECHANICAL AND ELECTRICAL EQUIPMENT - WATANA STAGE II I (***)••••••••••••••A-14-1 14.1 Miscellaneous Mechanical Equipment (***)A-14-1 14.2 -Accessory Electrical Equipment (***)..A-14-1 TRANSMISSION FACILITIES -WATANA STAGE III (***) 15.1 Transmission Requirements (***)• 15 - I I I -I -( 15.2 Switching and Substations (***). 15.2.1 -Watana Switchyard (***)..••. 15.2.2 -Gold Creek Switchyard (***)•••••• 15.2.3 -Ester Substation (***)•. 15.2.4 -Willow Substation (***) 15.2.5 -Knik Arm Substation (***) 15.2.6 -University Substation (***).•.•.• A-15-1 A-15-1 A-15-1 A-15-1 A-15-1 A-15-2 A-15-2 A-15-2 A-15-2 851011 x J -I I I Title 16 -LANDS OF THE UNITED STATES (**)• TABLE OF CONTENTS (cont'd) EXHIBIT A PROJECT DESCRIPTION A-16-1 A-17-1 Page No. .... ....... . . ...17 -REFERENCES J 1 I I I ~I ) 651011 X~ I e-I I, -I -=1 i I 1 l I J J I I I I I r I I I -I I ! ] ( Number A.I 851011 EXHIBIT A PROJECT DESCRIPTION LIST OF TABLES Title PERTINENT PROJECT DATA Xl.l. J \ ~ ( \ I I I 9 -I ( I I ~EXHIBIT A PROJECT DESCRIPTION LIST OF FIGURES J Number Title -I A.1 PROPOSED PROJECT LOCATION I I I I I I I ! ) j I i ( i 851011 xiii J J EXHIBIT A PROJECT DESCRIPTION The Susitna Hydroelectric Project will be comprised of two major developments on the Susitna River some 120 miles north and east of Anchorage,Alaska (see Figure A.l).The project will be constructed ~n three distinct phases hereinafter referred to as stages. The following is a brief description of the three phases of the Project.A further description of Watana Stage I is presented in the following Sections 1 through 5;Devil Canyon Stage II is described in Sections 6 through 10.Watana Stage III is described in sections 11 through 15.Project lands for the entire project are discussed in Section 16.Reference drawings are in Exhibit F. WA TANA STAGE I The Watana Initial Dam would be built to el.2,025 with a maximum normal reservoir el.of 2,000 (see Exhibit F Figures).The internal zoning of the earthfill dam will include an inclined upstream impervious core.The inclination of the core will reduce the amount of shell material required for stability of the Stage III dam that will be submerged by the Stage I pool,and therefore placed during Stage I construction.When the dam is being raised,all the additional fill will then be placed in the dry during the seasonal draw down of the reservoir.The raising of the Watana Dam causes no adverse effects on the safety of ~ither the Stage I or Stage III dam,and no unusual construction operation is required during raising.An additional five feet of freeboard is added in Stage I to facilitate flood control with the small reservoir storage volume. The spillway and approach channel excavation would be deepened by approximately 185 feet below that shown in the original two stage project in order to accommodate the reservoir during Stage I.The rock excavated from these areas would be used in the construction of the dam and would minimize or eliminate the need for opening a quarry site during Stage I.The deeper excavation would be designed with suitable rock reinforcement and berms.The spillway in Stage I will pass the probable maximum flood. For Stage I,there would be one outlet facility structure and two power intake structures.The outlet facility,in conjunction with the four powerhouse units in Stage I,will discharge a 50-year flood before flow would be discharged over the spillway. The power house in Stage I will have four generating units,each with a nominal capability at average operating head of 110 MW for a total of 440 MW.The December -January dependable capability of the Stage I installation will be 360 MW. The construction schedule for Stage I will be one year shorter than the first stage of the two stage project.The shortening of the schedule 851011 A-l-l I ) \ J I l 1 -( I 1 --I 1 is a result of a decrease in the quant~t~es of the fill material necessary for the Stage I construction. DE VI L CANYON STAGE II Stage II will be the construction of the Devil Canyon development consisting of a concrete double curvature thin arch dam with crest el.1,463 (see Exhibit F Figures).The normal maximum reservoir will be at el.1,455.The powerhouse will have four units each with a nominal capability at average operating head of 170 MW for a total of 680 MW.The December -January dependable capability of the Devil Canyon powerplant will be 600 MW.Outlet facilities will be provided to discharge the routed 1:50 year flood in conjunction with the power facilities.A gated chute spillway with flip bucket will be provided capable of passing the proQable maximum flood.A saddle dam will be constructed on the right bank to el.1,472 and adjacent to the arch dam.The saddle dam will be an embankment of similar construction to the Watana Dam.During construction,diversion of the river will be accomplished by construction of upstream and downstream fill cofferdams and a diversion tunnel with capacity to pass the 1:25 year flood routed through the Watana Stage I reservoir. WATANA STAGE III The Watana Initial Dam would be raised to el.2,205 with a max~mum normal reservoir el.of 2,185-(see Exhibit F Figures).During seasonal drawdown when the Stage I reservoir elevation is below el. 1,925 (the elevation of the upstream berm)rockfill would be in the dry on the upstream side of the dam. The concrete spillway ogee crest would be raised to el.2,135 and the spillway gates relocated to accommodate the higher ogee elevation. The outlet facility structure and the two power intakes would be raised to el.2,201.A third power intake would be built in Stage III with an inlet at el.2,012. Two additional units would be added to the powerhouse bringing the total number of units to six.After completion of Stage Ill,the nominal capacity of the powerhouse at average operating head would increase from 440 MW to 1,110 MW because of the increase in head on the four Stage I units and the addition of two 185 MW nominal capacity units.The December -January dependable capability of Watana in Stage III will be 1020 MW for a total project dependable capability of 1620 MW. 1 -PROJECT STRUCTURES -WATANA STAGE I (**) 1.1 -General Arrangement (**) The Watana Stage I Dam will create a reservoir approximately 39 miles long,with a surface area of 20,000 acres,and a gross storage 851011 A-1-2 j -l 1 -( I l J \ I 1 j capacity of 4,300,000 acre-feet at the normal maximum operating level of el.2,000. The maximum water surface elevation during flood conditions will be 2,017.The minimum operating level of the reservoir will be 1,850, providing 2,400,000 acre-feet of live storage during normal operation. The dam will be an earth and rockfill embankment with an inclined impervious core.The nominal crest elevation of the dam will be 2,025, with a maximum height of approximately 700 feet above the foundation and a crest length of 2,700 feet.The embankment crest will initially be cambered to el.2,027 in the zone of maximum dam height to allow for potential seismic and static settlement.The total volume of the structure will be approximately 32,110,000 cubic yards.During construction,the river will be diverted through two concrete-lined diversion tunnels on the north side of the rivar,each 36 feet in diameter and averaging 3,700 feet long. The power intake will be located on the north bank with an approach channel excavated in rock.The intake will be a concrete structure with multi-level gates capable of operating over the full 150 foot drawdown range.From the intake structure,two 24 foot diameter concrete-lined power conduits and shafts will lead to an underground powerhouse complex,housing four generating units with Francis type turbines and synchronous generators.Near the powerhouse the conduits will branch into four IS-foot diameter steel-lined penstocks. Access to the powerhouse complex will be by means of an unlined access tunnel and a road which will pass from the crest of the dam,down the south bank of the river valley and across a berm constructed on the downstream toe of the main dam.Turbine discharge will flow through four draft tube tunnels to a surge chamber downstream from the powerhouse.The surge chamber will discharge to the river through a 34 foot modified-horseshoe concrete-lined tailrace tunnel.A separate transformer gallery just upstream of the powerhouse cavern will house seven single-phase 15-345/1.73 kV transformers (three transformers per group of two generators,and one spare),and an SF6 gas insulated substation.Each bank of transformers will be connected through generator circuit breakers by isolated phase bus located in individual bus tunnels.The HV bushings for the transformers will be connected to the 345 kV SF6 gas insulated substation (GIS)by single-phase SF6 gas insulated buses (GIB).The substation will provide switching for two transformer banks and two transmission lines.Two sets of single-phase SF6 GIB will be carried from the GIS to the surface through a single vertical shaft.At the surface the GIB will be terminated at SF6-to-air entrance bushings where they will be connected to overhead transmission lines. Outlet facilities will also be located on the north bank with a capacity of approximately 24,000 cfs.A flood storage pool is provided 851011 A-1-3 -1 1 ) '-=-1 l l 1 1 1 J 1 ( 1 J between e1.2,000 and el.2,014. powerhouse flow of 9,200 cfs,the released without raising the pool requiring use of the spillway. In combination with the average 50-year flood can be stored and level above el.2,014 and without -~ The spillway located on the north bank will consist of an upstream ogee control structure with three radial gates and an inclined concrete chute and flip bucket designed to pass a maximum discharge of 278,300 cfs.This spillway,together with the outlet facilities,will be capable of discharging the estimated Probable Maximum Flood (PMF)of 326,000 cfs,while maintaining eight feet of freeboard on the dam. Emergency release facilities will be located in one of the diversion tunnels after closure to allow lowering of the reservoir over a period. of time for emergency inspection or repair of impoundment structures. 1.2 -Dam Embankment (**) The Watana Stage I Dam embankment will be located at mile 184 above the mouth of the Susitna River,in a broad U-shaped valley approximately 2.5 miles upstream of the Tsusena Creek confluence.The dam will be of compacted earth and rockfill construction and will consist of an impervious core protected by fine and coarse filters upstream and downstream.The upstream and downstream outer shells will consist of rockfill.A typical cross section is shown on plate F7 and is described below. 1.2.1.Typical Cross Section (**) The thickness of the core at any horizontal section will be slightly more than 0.5 times the head of water at that section. Flaring will be required of the cross section at each end of the embankment. The upstream and downstream filter zones are sized to provide protection against possible piping through transverse cracks that could occur because of settlement or resulting from internal displacement during a seismic event. The shells of the dam will consist of rockfill obtained from required surface or underground excavations.The rockfill will minimize pore pressure generation and insure rapid dissipation of pore pressures should seismic shaking occur. Protection against wave and ice action on the upstream slope will consist of a rock raked layer of large stone comprising quarried rock up to 36 inches in size. 851011 A-1-4 i I I ) j \ -( 1 I ] _J I I J The volume of material required to construct the Watana Dam LS presently estimated as follows: J Material Impervious Fine filter Coarse filter Rockfill Volume (cy) 6,300,000 2,217,000 2,000,000 21,590,000 851011 1.2.2 -Crest Details and Freeboard (**) The typical crest detail is shown in Plate F7.Because of the narrowing at the dam crest,the filter zones are reduced in width,but still protect the core material from damage by frost penetration and desiccation. The nominal crest elevation of Watana Stage I will be 2,025. Total settlement allowance has been made for post-construction settlement of the dam under its own weight,for the effects of saturation on the upstream rock fill when the reservoir is first filled,and for possible settlement from seismic shaking. Provision will be made during construction for placement of additional fill at the crest should settlements exceed the estimated amounts.At each abutment the crest elevation will be 2,025,while at the maximum section the crest elevation will be 2,027 allowing for two feet of settlement.Under normal operating conditions theminbnum freeboard,relative to the maximum operating pool elevation of 2,000,will be approximately 25 feet,not including settlement allowances. The freeboard allowance is eight feet above the PMF reservoir level and is based on the crest level after all settlement has taken place.Ultimate security against overtopping of the main dam will be provided by the spillway which is designed to pass the PMF without overtopping the dam. 1.2.3 -Grouting and Pressure Relief System (**) A combination of consolidation grouting,grout curtain and installation of a downstream pressure relief (drainage)system will be undertaken in the bedrock foundation beneath Watana Dam. The grout curtain and drilling for the pressure relief system will be largely carried out from galleries in the rock foundation in the abutments and beneath the dam.Details of the grouting, pressure relief and galleries are shown on Plate F8. A-1-5 -I I J J 1 ) i ) l 1 I I -I I I j J I ~ J J 1.2.4 -Instrumentation (**) Instrumentation will be installed to provide monitoring of performance of the dam and foundation during construction as well as during operation.Instruments for measuring internal vertical and horizontal displacements,stresses and strains,and total and fluid pressures,as well as surface monuments and markers,will be installed.Conservative quantity estimates for instrumentation have been made on the basis of currently available geotechnical data for the site.This instrumentation includes: o Piezometers Piezometers will be used to measure hydrostatic pressure in the pore spaces of soil and rockfill,and in the rock foundation. a Internal Vertical Movement Devi~es -Cross-arm settlement devices, -Various versions of the taunt-wire devices which have been developed to measure internal settlement,and Hydraulic-settlement devices of various kinds. o Internal Horizontal Movement Devices Taunt-wire arrangements, -Cross-arm devices, -Inclinometers,and -Strain meters. o Other Measuring Devices -Stress meters, -Surface monuments and alignment markers, -Seismographic records and seismoscopes,and -Flow meters to record discharge from drainage and pressure relief system. 1.3 -Diversion (**) 1.3.1 -Tunnels (**) Diversion of the river flow during construction will be accomplished with two 36-foot diameter circular diversion tunnels.The tunnels will be concrete-lined and located on the north bank of the river.The tunnels are 3,305 feet and 4,020 feet in length.The diversion tunnels are shown in plan and profile on Plate F9. 851011 A-I-6 -I I ~ I 1 '! l -) 1 j J ) I r i~ j 851011 The tunnels are designed to pass a flood with a return frequency of 1:50 years,equivalent to peak inflow of 89,500 cfs.Routing effects are small,and thus at peak flow the tunnels will discharge 77,000 cfs.The estimated maximum water surface elevation upstream from the cofferdam for this discharge will be 1,532. The upper tunnel (Tunnel No.1)will be converted to the permanent emergency outlet after construction.A local enlarging of the tunnel diameter to 45 feet will accommodate the low-level outlet gates and expansion chamber. 1.3.2 -Cofferdams (**) The upstream cofferdam will be a zoned embankment founded on the diversion dike (see Plate FlO).The diversion dike will be constructed to e1.1,480,and will consist of finer material on the upstream side grading to coarser material on the downstream side.Provision has been made for a slurry trench cutoff through the river bed alluvium to bedrock to control seepage during dam construction.The slurry wall cutoff is shown on Plate FlO. The upstream cofferdam will receive the usual foundation treatment and will be a zoned embankment consisting of an impervious core,fine and coarse upstream and downstre,sm filters, and rock and/or gravel supporting shell zones with slope protection on the upstream face to resist ice action.This cofferdam will be constructed to el.1,550 and provide an IS-foot freeboard for wave run-up and ice protection. The downstream cofferdam will be a zoned earth and rockfil1 embankment (see Plate F-IO).The diversion dike will be constructed to el.1,460,and will consist of random rock material placed on the downstream side of the cofferdam section. The cofferdam will be raised in the dry to its crest elevation of 1,495.The diversion scheme will allow an unwatering of the river reach between the cofferdams,so the slurry trench cut-off to bedrock may be constructed for control of under seepage. 1.3.3 -Tunnel Portals and Gate Structures (**) A reinforced concrete gate structure will be located at the upstream end of each tunnel,each housing two closure gates (see Plate FlU. Each gate will be 36 feet high by 14 feet wide separated by a center concrete pier.The gates will be of the fixed-roller vertical lift type operated by a wire rope hoist.The gate hoist will be located in an enclosed,heated housing.Provision will be made for heating the gates and gate guides.The gate in A-1-7 J 1 ~ ( ) J j I I ) I ) -( I j -\ ,j J ) ,\ -) ··1 \ .1 Tunnel No.1 will be designed to operate with the reservoir at el.1,532,a 64~foot operating head.The gate in Tunnel No.2 will be designed to operate with the reservoir at el.1,532,an 87-foot operating head.The gate structures for each tunnel will be designed to withstand external (static)heads of 160 feet (No. 2)and 500 feet (No.1),respectively.The downstream portals will be reinforced concrete structures with guides for stoplogs. 1.3.4 -Final Closure and Reservoir Filling (**) As discussed above,the upper diversion tunnel (No.1)will be converted to a low-level outlet or emergency release facility during construction. It is estimated that one year will be required to construct and install the permanent low-level outlet in the existing tunnel. This will require that the lower tunnel (No.2)pass all flows during this period.The main dam will,at this time,be at an elevation sufficient to allow a lOa-year recurrence interval flood (99,000 cfs)to pass through Tunnel No.2.This flow will result in a reservoir elevation of approximately 1,618.During the construction of the low level outlet,the intake gates in the upper tunnel (No.1)will be closed.Prior to commencing operation of the low-level outlet,coarse trashracks will be idstalled at the entrance to Tunnel No.1 intake structure. Upon commencing operation of the low-level outlet,the lower tunnel (No.2)will be closed with the intake gates,and construction of the permanent plug and filling of the reservoir will commence. When the lower tunnel (No.2)is closed the main dam crest will have reached an elevation sufficient to start filling the reservoir and still have adequate storage available to store a 250-year recurrence period flood. During the filling operation,the low-level outlet will pass summer flows of up to 12,000 cfs and winter flows of up to 800 cfs.In case of a large flood occurring during the filling operation,the low-level outlet would be opened to its maximum capacity of 30,000 cfs to maintain the reservoir pool at a safe leve 1. Reservoir filling is estimated to take one year to fill to a level required for testing,commissioning,and operating the first two units during the first winter.Completion of filling to el.2,000 would occur during the second summer. The filling sequence is based on the main dam elevation at any time during construction and the capability of the reservoir 851011 A-1-8 I I l 1 ( J storage to absorb the inflow volume from a 2S0-year recurrence period flood without overtopping the main dam. 1.4 -Emergency Release Facilities (**) The upper diversion Tunnel No.1 will be converted to a permanent low- level outlet,or emergency release facility.These facilities will be used to pass the required minimum discharge during the reservoir filling period and will also be used for draining the reservoir in an emergency. During operation,energy will be dissipated by means of two gated con- crete plugs separated by a 340-foot length of tunnel (see Plate F19). Each plug will contain three water passages. Bonnetted type high pressure slide gates will be installed in each of the passages in the tunnel plugs.The gate arrangement will consist of one emergency gate and one operating gate in the upstream plug and one operating gate in the downstream plug.A 340-foot length of tunnel between plugs will act as an energy dissipating expansion chamber. The 7.S-foot by II.S-foot gates will be designed to withstand a total static head of about 720 feet;however,they will only be operated with a maximum head of about 420 feet. During operation,the operating gate opening in the upstream plug will be equal to the opening of the corresponding gate in the downstream plug.This should effectively balance the head across the gates. Each gate will have a hydraulic cylinder operator designed to raise or lower it against a maximum head of 600 feet.Three hydraulic units will be installed,one for the emergency gates,one for the upstream operating gates and one for the downstream operating gates.Each gate will have an opening/closing time of about 30 minutes.A grease injec- tion system will be installed in each gate to reduce frictional forces when the gates are operated. The design of the gate will be as the cylinder packing may be ing the area around the gate. operated. such that inspected All gates the hydraulic cylinder as well and repaired without dewater- may be locally or remotely To prevent concrete erosion,the conduits in each of the tunnel plugs will be steel-lined.An air vent will be installed at the downstream side of the operating gate in the downstream plug.Energy dissipation at the downstream tunnel exit will be accomplished by means of a con- crete flip bucket in the exit channel (Plate F20). 8S1011 A-1-9 I,---l I ~, I -I :I I i I( l 1.5 -Outlet Facilities (**) The primary function of the outlet facilities will be to discharge floods with recurrence frequencies of up to once in 50 years after they have been routed through the Watana reservoir.The use of fixed-cone discharge valves will ensure that downstream erosion will be minimal and the dissolved nitrogen content in the discharges win be reduced sufficiently to avoid harmful effects on the downstream fish population.A secondary function will be to provide the capability to rapidly draw down the reservoir during an extreme emergency situation. The facilities will be located on the north bank and will consist of a gate structure,pressure tunnel,and an energy dissipation and control struc ture housing located beneath the spillway flip bucket.This structure will accommodate six fixed-cone valves which will discharge into the river 105 feet below. 1.5.1 -Approach Channel and Intake (**) The approach channel to the outlet facilities will be shared with the power intake and spillway.The channel at the maximum normal operating level of el.2,000 will be 680 feet wide irnmediately upstream of the outlet facility's gate structure. The gate structure will be founded deep in the rock at the fore bay end of the channel.The single intake passage will have an invert elevation of 1,915.It will be divided upstream by a central concrete pier which will support steel trashracks located on the face of the structure,spanning the openings to the water passage.The trashracks will be split into panels mounted one above the other and run in vertical steel guides installed at the upstream face.The trashrack panels can be raised and lowered for cleaning and maintenance by a mobile gantry crane located at deck level. Two fixed-wheel gates will be located downstream of the trashracks between the pier and each of the sidewalls.These gates will be operated by a hydraulic hoist mounted in the gate shaft.The fixed-wheel gates will not be used for flow control but will function as closure gates to isolate the downstream tunnel and allow dewatering for maintenance of the tunnel or ring gates located in the discharge structure.Stoplog guides will be provided upstream from the two fixed-wheel gates to permit dewatering of the structure and access to the gate guides for maintenance. 1.5.2 -Intake Gates and Trashracks (**) The gates will be of the fixed-wheel vertical lift type with upstream skinplate and seals.The nominal gate size will be 18 851011 A-l-IO l l 851011 feet wide by 28 feet high.Each gate will be operated by a hydraulic hoist located above the gate in the gate shaft. The gates will be capable of being lowered either from a remote control room or locally from the intake area.Gate raising will be from the hoist area only. The trashracks will have a bar spacing of 6 inches and will be designed for a maximum differential head of 40 feet.The maximum net velocity through the racks will be approximately 7.5 ft/sec. Provision will be made for monitoring the head loss across the trashracks. 1.5.3 -Shaft and Tunnel (**) Discharges will be conveyed from the upstream gate structure by a concrete-lined tunnel terminating in a steel liner and manifold.The manifold will branch into six steel-lined tunnels which will run through the main spillway flip bucket structure to the fixed-cone valves mounted in line with the downstream face. The water passage will be 28 feet in diameter from the intake to the steel manifold.The upstream concrete-lined portion will run a short distance horizontally from the back of the intake structure before dipping at an angle of 55°to a lower level tunnel of similar cross section.The lower tunnel will run at a 5 percent gradient to a centerline elevation of 1,560 approximately 450 feet upstream of the flip bucket.At this point the depth of overlying rock is insufficient to withstand the large hydrostatic pressure which will occur within the tunnel.Downstream of this point the tunnel will be steel-lined. The steel liner will be 28 feet in diameter and embedded in concrete filling the space between the liner and the surrounding rock.The area between the outside face of the liner and the concrete will be contact grouted. 1.5.4 -Discharge Structure (**) The concrete discharge structure is shown on Plate F15.It will form a part of the flip bucket for the main spillway and will house the fixed-cone valves and individual upstream ring follower gates.The valves will be set with a centerline elevation of 1,560 and will discharge into the river approximately 105 feet below.Openings for the valves will be formed in the concrete and the valves will be recessed within these openings sufficiently to allow enclosure for ease of maintenance and heating of the movable valve sleeves.An access gallery upstream from the valves will run the length of the discharge structure,and will terminate in the access tunnel and access road on either side of the structure. A-l-11 i I I I I l 1 \ i ( I I J -I l 851011 Housing for the ring follower gates will be located upstream from the fixed-cone valve chambers.The ring follower gates will serve to isolate the discharge valves.Provision will be made for relatively easy equipment maintenance and removal by means of a 25-ton service crane,transfer trolley and individual 25-ton monorail hoists. 1.5.5 -Fixed-Cone Discharge Valves (**) six 78-inch diameter fixed-cone discharge valves will be installed at the downstream end of the outlet manifold,as shown on Plate F15.The valves will be operated by two hydraulic cylinder operators.The valves will be operated either locally or remotely. 1.5.6 -Ring Follower Gates (**) A ring follower gate will be installed upstream from each valve and will be used: o To permit inspection and maintenance of the fixed-cone valves; o To relieve the hydrostatic pressure on the fixed-cone valves when they are in the closed position;and o To close against flowing water in the event of malfunction or failure of the valves. The ring follower gates will have a nominal diameter of 90 inches and will be designed to withstand a total static head of 630 feet. The ring follower gates will be designed to be lowered under flowing water conditions and raised under balanced head conditions.A grease injection system will be installed in each gate to reduce frictional forces when the gates are operated. The gates will be operated by hydraulic cylinders from either a local or remote location. 1.5.7 -Discharge Area (**) Immediately downstream from the discharge structure,the rock will be excavated at a slope of 2H:3V to a lower elevation of 1,510.This face will be heavily reinforced by rock bolts and protected bya concrete slab anchored to the face.The lower level will consist of unlined rock extending to the river. A-1-12 --I I I 4 ( I I I l l \ I \ I f ! -I 1.6 -Spillway (**) The spillway will provide discharge capability for floods exceeding the capacity of the outlet facilities (50-year flood).The combined total capacity of the spillway and outlet facilities will be sufficient to pass the PMF. The spillway,shown on Plate F12,will be located on the north bank of the river and will consist of an approach channel,a gated agee control structure,a concrete-lined chute,and a flip bucket. The spillway is designed to discharge flows corresponding reservoir elevation of 2,014. by the spillway is approximately 545 feet. of up to 258,000 cfs with a The total head dissipated 1.6.1 -Approach Channel and Control Structure (**) The approach channel at the spillway will be excavated to a depth of approximately 335 feet into rock.It will be located on the north side of the power and outlet facilities intakes,and will be integrated with the approach channels upstream of these intake structures. The concrete control structure will be located at the end of the approach channel.Flows will be controlled by three 64-foot high by 44-foot wide radial gates,as shown on Plate Fl3.The structure will be constructed.in individual monolitlls separated by contraction joints.The main access route to the dam will pass across the roadway deck and along the dam crest. Hydraulic model tests will be undertaken during the detailed design stage to confirm the precise geometry of the control structure. The sides of the approach channel will be excavated to lH:4V slopes.Only localized rock bolting and shotcrete support are expected.The control structure will be founded deep in sound rock and consolidation grouting is not anticipated.However, minor shear or fracture zones passing through the foundation may require dental excavation,concrete backfill and/or consolidation grouting. The dam embankment grouting and drainage tunnel will join the control structure gallery.Access to the grouting tunnels will be via a vertical shaft within the control structure side wall and a gallery running through the agee weir. 851011 A-I-I3 J ) ( I ( i j I i -I -I 851011 1.6.2 -Spillway Gates and Stoplogs (**) The three spillway gates will De of the radial type operated by hydraulic hoists mounted at the sides of the piers downstream of the gates.The gate size is 44 feet wide by 64 feet high. provision will also be made for heating the gate guides for winter operation. An emergency engine wi 11 be provided to enable the gates to be raised in the event of loss of power to the spillway's gate hoist motor hydraulic system. Stoplog guides will be installed upstream of each of the three spillway gates.One set of stoplogs will be provided to permit maintenance of the radial gates. 1.6.3 -Spillway Chute (**) The control structure will discharge down an inclined chute that tapers uniformly until a width of 120 feet is reached near the flip bucket.Convergence of the chute walls as such will be gradual to minimize any shock wave development. The chute section will be rectangular in cross section,excavated in rock,and lined with concrete anchored to the rock.An extensive underdrainage system will be provided to ensure stability of the structure.The dam grout curtain and drainage system will also extend under the spillway control structure utilizing a gallery through the mass concrete rollway.A system of box drains will be constructed in the rock under the concrete slab in a herringbone pattern at 20 feet spacing for the entire length of the spillway.A drainage trench will be excavated beneath the entire length of the spillway.Drain pipes will intersect the gallery.Drainage holes drilled into the high rock cuts will alao ensure increased stability of excavations. A series of four aeration galleries will be provided at intervals down the chute to prevent cavitation damage of the concrete. Details of these aeration devices are shown in Plate F14. 1.6.4 -Flip Bucket (**) The function of the flip bucket will be to direct the spillway flow clear of the concrete structures and well downstream into the river below.A mass concrete block will form the flip bucket for the main spillway.Detailed geometry of the bucket, as well as dynamic pressures on the floor and walls of the structure,will be confirmed by model studies. A-I-14 ~, 1.7 -This section deleted 1.8 -Power Intake (**) 1.8.1 -Intake Structure (**) The power intake will be a concrete structure located deep in the bedrock on the north bank.Access to the structure will be by road from the south side of the spillway bridge. In order to draw from the reservoir surface over a drawdown range of 150 feet,two openings at five levels will be provided in the upstream concrete wall of the structure for each of the two independent power intakes serving the four generating units. Openings can be closed off by sliding steel shutters operated ~n a common guide.All openings will be protected by upstream trashracks.A heated boom will operate in guides upstream from the racks following the water surface,keeping the racks ice free. Two lower control gates will be provided in each intake unit.A single set of upstream bulkhead gates will be provided for routine maintenance of the two sets of intake gates. The overall base width of the intake will be 150 feet,providing a minimum spacing of power tunnel excavations of 2.75 times the excavated diameter. The upper level of the concrete structure will be set at el.2,020.The level of the lowest intake is governed by the vortex criterion for flow into the penstock from the minimum reservoir level elevation of 1,850.The foundation of the structure will be approximately 400 feet below existing ground level and is expected to be in sound rock. The wall between intake structures will be perforated with a series of holes (see Plate F24)in the section between the guides for the shutter gates and the bulkhead gate.These perforations will allow for a more uniform withdrawal distribution across the approach channel width when only one power tunnel is conveying water. Mechanical equipment will be housed in a steel-frame building on the upper level bf the concrete structure.The general arrangement of the power intake is shown on Plate F24. 851011 A-I-IS ~ I I ( I ( ( I ! l I ( j ( 1 1 ( l 1.8.2 -Approach Channel (**) The overall width of the approach channel at the upper shutter gate level is governed by the combined width of the power intake outlet facilities gate structure and spillway control structure,and will be approximately 700 feet.The length of the channel will be 1,600 feet. The maximum velocity in the intake approach channel will occur when four machines are operating with the reservoir drawn down to el.1,850.The velocity in the approach channel will be 1.4 ft/sec,which will not cause any erosion problems. Velocities of 6.2 ft/sec may occur where the intake approach channel intersects the appr6ach channel to the main spillway. 1.8.3 -Mechanical Arrangement (**) (a)Ice Boom (**) A heated boom will be installed in guides immediately upstream from the trashracks for each of the two power intakes.The boom .will be operated by a movable hoist and will automatically follow the reservoir level.The boom will serve to minimize ice accumulation in the trashrack and intake shutter area,and prevent thermal ice-loading on the trashracks. (b)Trashracks (**) Each of the two power intakes will have five sets of trashracks,one set in front of each pair of intake openings.Each set of trashracks will be in two sections to facilitate handling by the intake service crane.Each set of trashracks will cover two openings each 24 feet wide by 25 feet.The trashracks will have a bar spacing of six inches and will be designed for a maximum differential head of 20 feet. (c)Intake Shutters (**) Each of the two power intakes will have four sets of intake shutters which will serve to prevent flow through the openings behind which the shutters will be installed. As the reservoir level drops,the sliding shutters will be removed as necessary using the intake service crane. Each of the shutters will be designed for a differential head of 15 feet,and will incorporate a flap gate.This will prevent failure of the shutters in the event of accidental blocking of all intake openings. 851011 A-1-16 I I \ I I ( l ! \ J The shutter guides will be heated to facilitate shutter removal in sub-freezing weather.In addition,a bubbler system will be provided in the intake behind the shutters to keep the intake structure water surface free of ice. (d)Intake Service Crane (**) A single overhead traveling-bridge type intake service crane will be provided in the intake service building.The crane will be used for: o Servicing the ice boom and ice boom hoist o Handling and cleaning the trashracks o Handling the intake shutters o Handling the intake bulkhead gates and o Servicing the intake gate and hoist The overhead crane will have a double point lift and followers for handling the trashrack,shutters and bulkhead gates.The crane will be radio-controlled with a pendant or cab control for backup. (e)Intake Bulkhead Gates (**) One set of intake bulkhead gates will be provided for closing the two intakes upstream of the intake gates.The bulkhead gates will be used to permit inspection and maintenance of the intake gate and intake gate guides.The gates will be designed to withstand full differential pressure. (f)Intake Gates (**) The intake gates will close the two openings of 12 feet by 24 feet of each power intake.They will be of the vertical fixed-wheel lift type with upstream seals and skinplate. Each gate will be operated by a hydraulic cylinder type hoist.The length of a cylinder will allow withdrawal of the gate from the water flow.The intake service crane will be used to raise the gate above deck level for maintenance. The gates will normally be closed under balanced flow conditions to permit dewatering of the power tunnel penstock water passages for inspection and maintenance.The gates will also be designed to close in an emergency with full turbine flow conditions in the event of loss of control of the turbine. 851011 A-l-17 1 l ~ ( l 1 1 ! I i ) 1.9 -Power Tunnels and Penstocks (**) The general arrangement of the power tunnels and penstocks 1S shown on Plates F2l and F23. Two power tunnels,each of which bifurcate to penstocks,are provided to convey water from the power intakes to the powerhouse,one penstock for each generating unit.The power tunnel geometry shall consist of a short horizontal reach,a 90 degree bend,a shaft,another 90 degree bend and a short horizontal reach before the bifurcation.The power tunnel will be concrete lined with internal diameter of 24 feet.Each penstock will be a concrete-lined tunnel 18 feet in internal diameter. The minimum concrete lining thickness will be 18 inches.The lateral spacing between power tunnels will be 75 feet on centers at the intake and the penstocks,and 60 feet on centers at the powerhouse.The difference in lateral spacing will be achieved by staggering the bifurcation point of each power tunnel. The design static head on each penstock is 763 feet,the Stage III maximum normal reservoir level~at centerline distributor level (el.1,422).An allowance of 35 percent has been made for pressure rise in the penstock caused by hydraulic transients. 1.9.1 -Steel Liner (**) The rock immediately adjacent to the powerhouse cavern will be incapable of resisting the internal hydraulic forces within the penstocks.Consequently~the first 50 feet of each penstock upstream of the powerhouse will be reinforced by a steel liner designed to resist the maximum design head,without support from the surrounding rock.Beyond this section the steel liner will be extended a further 150 feet,and support from the surrounding rock will be assumed,up to a maximum of 50 percent oE the design pressure. The steel liner will be surrounded by concrete with a m1nlmurn thickness of 18 inches.The internal diameter of the steel lining will be 15 feet.A steel transition will be provided between the liner and the IS-foot diameter concrete-lined penstock. 1.9.2 -Concrete Lining (**) The power tunnels and penstocks will be fully lined with concrete from the intake to the steel-lined section of the penstocks.The internal diameter of the concrete-lined penstock will be 18 feet.The minimum lining thickness will be 18 inches. 851011 A-1-18 I ~ _I I i I i l [ I I l 1.9.3 -Grouting and Pressure Relief System (**) A comprehensive pressure relief system will protect the underground caverns against seepage from the high pressure penstock.The system will comprise small diameter boreholes set out to intercept the jointing in the rock.A grouting and drainage gallery will be located upBtream from the transformer gallery. 1.10 -Powerhouse (**) The underground powerhouse complex will be constructed beneath the north abut~ent of the dam.This will require the excavation in rock of taree major caverns,the powerhouse,transformer gallery,and surge chamber,with interconnecting rock tunnels for the draft tubes and isolated phase bus ducts. Unlined rock tunnels,with concrete inverts where appropriate,will be provided for vehicular access to the three main rock caverns and the penstock construction adit.Vertical shafts will be provided for personnel access to the underground powerhouse,for SF6 gas-insulated busses from the transformer gallery,for surge chamber venting,and for the heating and ventilation system. The general layout of the powerhouse complex is shown in plan and sec- tion on Plates F25 and F26,and in isometric projection on Plate F24. The transformer gallery will be located on the upstream side of the ?owerhouse cavern;the surge chamber will be located on the downstream side. The draft tube gate gallery and crane will be located in the surge chamber cavern,above the maximum anticipated surge level.Provision will also be made in the surge chamber for tailrace tunnel intake stop- logs,which will be handled by the same crane. 1.10.1 -Access Tunnels and Shafts (**) Vehicular access to the underground facilities at Watana will be provided by a single unlined rock tunnel from the north bank area at el.1,560,adjacent to the diversion tunnel portals.The access tunnel will descend to the south end of the powerhouse cavern at generator floor level,el.1,463.Separate branch tunnels from the main tunnel will provide access to the transformer gallery at el.1,507,and the surge chamber at el. 1,495.A separate penstock construction adit will be driven to el.1,420 from immediately downstream of the diversion tunnel portals.The gradient will not exceed 0.3 percent at the construction access tunnel,and 9.5 percent at the permanent access tunnels,except for along the short transformer access tunnel where the gradient is 11 percent. 851011 A-1-19 I I J I I -I l I ! ! 1 I ! J 1 The cross section of the access tunnel has a modified horseshoe shape,35 feet wide by 28 feet high.The access tunnel branch to the surge chamber and draft tube gallery will have a reduced section consistent with the anticipated size of vehicle and loading required. The main access shaft will be at the north end of the powerhouse cavern,providing personnel access from the surface control building by elevator.Access tunnels will be provided from this shaft for pedestrian aCcess and ventilation to the transformer gallery and the draft tube gate gallery and ventilation. Elevator access will also be provided to the fire protection head tank,located approximately 250 feet above powerhouse level.The main access shaft will be 20 feet in internal diameter with a concrete lining of 9 to 18 inches. 1.10.2 -Powerhouse Cavern (**) The main powerhouse cavern will be designed to accommodate four vertical-shaft Francis turbines,in line,with direct coupling to synchronous generators.The length of the cavern will allow for a unit spacing of 60 feet,with a 95-foot long service bay at the south end for routine maintenance and for construction erection.Vehicular access will be by tunnel to the generator floor at the south end of the cavern;pedestrian access will be by elevator from the surface control building to the north end of the cavern.Multiple stairway access points will be available from the main floor to each gallery level.Access to the transformer gallery from the powerhouse will be by tunnel from the main access shaft,or by stairway through each of the isolated phase bus tunnels.A service elevator will be provided for access to the various powerhouse floors. Hatches will be provided through all main floors for installation and maintenance of heavy equipment using the powerhouse cranes. In order to minimize interruption to power generation during future Stage III extension,the powerhouse superstructure excavation will be extended by five feet,bringing the total Stage I excavation length to 365 feet above el.1,441. Similarly,a 76 foot long drainage tunnel will be excavated to allow gravity drainage to occur from the future bays to Unit 4 sumps. 1.10.3 -Transformer Gallery (**) The transformers will be located underground in a separate gallery,120 feet upstream from the main powerhouse cavern, with two connecting tunnels for the isolated phase bus.There will be six single-phase transformers installed in groups of 851011 I I J l I ~l 1 I ! ] \ J 851011 three transformers for two generating units.Generator circuit breakers will be installed in the powerhouse on the generator floor leve 1. The transformer gallery will be 45 feet wide,40 feet high,and 308 feet long;the bus tunnels will be 16 feet wide and 16 feet high. Two sets of 345 kV SF6 gas-insulated busses will be taken to the surface by a single vertical shaft with an internal diameter of 9.0 feet.Provision will be made for installation of an inspection hoist in the shaft.A spare transformer will be located in the transformer gallery.The station service auxiliary transformers (2 MVA)and the surface auxiliary transformer (7.5/10 MVA)will be located in the bus tunnels. Generator excitation transformers will be located in the powerhouse on the main floor. Vehicle access to the transformer gallery will be the main powerhouse access tunnel at the south end.Pedestrian access will be from the main access shaft or through each of the two isolated phase bus tunnels. The transformer gallery will also be over-excavated by five feet similar to the powerhouse cavern bringing the total excavated Stage I length to 308 feet. 1.10.4 -Surge Chamber (**) A surge chamber will be provided 120 feet downstream from the powerhouse cavern to control pressure fluctuations in the turbine draft tubes and tailrace tunnels under transient load conditions,and to provide storage of water for the machine start-up sequence.The chamber will be common to all four draft tubes,and will discharge into a tailrace tunnel.The overall surge chamber size is 290 feet long,50 feet wide,and 150 feet high (including the draft tube gate gallery). The draft tube gate gallery and crane will be located in the same cavern,above the maximum anticipated surge level.The crane has also been designed to allow installation of tailrace tunnel intake stoplogs for emergency closure of the tailrace tunnel. The chamber will generally be an unlined rock excavation,with localized rock support as necessary for stability of the roof arch and walls.The gate guides for the draft tube gates and tailrace stoplogs will be embedded in reinforced concrete,and anchored to the rock by rock bolts. A-1-21 I 1 J I I I ! I I I I 1 I j I I I I 1.10.5 -Grouting and Pressure Relief System (**) Control of seepage in the powerhouse area will be achieved by a grout curtain upstream from the transformer gallery and an arrangement of drain holes downstream from this curtain.In addition,drain holes will be drilled frmo the caverns extending to a depth greater than the rock anchors.Seepage water will be collected by surface drainage channels and directed into the powerhouse drainage system. J -I Access to the draft main access tunnel. storage of tailrace tube gate gallery will be by an adit from the This access will be widened locally for tunnel intake stoplogs. 1.10.6 -SF6 Gas Insulated Bus Shaft (**) The SF6 gas-insulated bus shaft will be 9 feet internal diameter. Although not required for rock stability,a 9-inch thick concrete lining has been specified for convenience of installing hoi~t,stairway and cable supports. 1.10.7 -Draft Tube Tunnels (**) The draft tube tunnels will be shaped to provide a transition to a uniform horseshoe section with a 19-foot diameter and a concrete lining approximately two feet thick.The initial rock support will be concentrated at the junctions with the powerhouse and surge chamber where the two free faces give greatest potential for block instability~ 1.11 -Tailrace (**) The tailrace pressure tunnel surge chamber to the river. horseshoe cross section with will be provided to carry water from the The tunnel will have a modified a major internal dimension of 34 feet. The tunnel will be fully concrete-lined throughout,with a minimum concrete thickness of 18 inches and a length of 1,430 feet.The tailrace tunnel will be arranged to discnarge into the river between the dam and spillway.The tunnel will start at the downstream wall of the surge chamber and then turn parallel to it until joining the penstock construction adit.The tunnel portal will be used Ear the tailrace outlet.The tunnel will be concrete-lined for hydraulic considerations.A rock berm will be left in place to the south of the portal to separate the outlet and diversion tunnel channels. The tailrace portal will be a reinforced concrete structure designed to reduce the outlet flow velocity,and hence the velocity head loss at the exit to the river. 851011 A-1-22 J I I I I I I J -I 1.12 -Main Access Plan (**) 1.12.1 -Access Objectives (*) The primary objective of access is to provide a transportation system that will support construction activities and allow for the orderly development and maintenance of site facilities. 1.12.2 -Access Plan Selection (**) Detailed access studies resulted in the development of eighteen alternative access plans within three distinct corridors.The- three corridors were identified as: o A corridor running west to east from the Parks Highway to the damsites on the north side of the Susitna River; o A corridor running west to east from the Parks Highway to the damsites on the south side of the Susitna River;and o A corridor running north to south from the Denali Highway to the Watana damsite. Criteria were established to evaluate the responsiveness of the plans to project objectives and the desires of the resource agencies and affected communities.The selected access plan (Plan 18,otherwise referred to as Denali-North)represents the most favorable solution to meeting both project related goals and minimizing impacts to the environment and the surrounding communities.Where adverse environmental impacts are unavoidable or project objectives compromised,mitigation and management measures have been formulated to reduce these impacts to a minimum.These mitigation measures are outlined in detail within Exhibit E of the license application. 1.12.3 -Description of Access Plan (**) Access to the Watana damsite will co~nect with the existing Alaska Railroad at Cantwell where a railhead and storage facility occupying 40 acres will be constructed.This facility will act as the transfer point from rail to road transport and as a storage area for backup supply of materials and ~quipment. From the railhead facility the road will follow an existing route to the junction of the George Parks and Denali Highways (a distance of two miles),then proceed in an easterly direction for a distance of 21.3 miles along the Denali Highway.A new road, 41.6 miles in length,will be constructed from this point due south to the Watana camp site.On completion of tne dam,access to Native lands on the south side of the Susitna River will be provided from the Watana camp site with the road crossing along 851011 A-l-23 I I J 1 1 I I I I I I J the top of the dam.This will involve the constcuction of an additional 2.6 miles of road bringing the total length of new road to 44.2 miles. Plate F2 shows the proposed access plan route.Plate F3 shows details,for both the Watana and Devil Canyon developments,of typical road and railroad cross sections,railhead facilities, and the high-level bridge at Devil Canyon. Assessment of projected traffic volumes and loadings during construction resulted in the selection of the following design parameters for the access roads. Surfacing Width of Running Surface Shoulder Width Design Speed Haximum Grade Maximum Curvature Stopping Site Distance Design Loading -during construction -after constcuction Unpaved (Treated Gravel Surface) 24 feet 4 feet 50 mph 5% "3/0o4 475 feet 8U k axle,200 k total HS -20 These design parameters were chosen for the efficient, economical,and safe movement of supplies and are in accordance with Federal Department of Transportation design standards. In the community of Cantwell the road will be paved marshalling yard to four miles east of the junction Parks and Denali Highways.This will eliminate any dust and flying stones in the residential district. the following measures will be taken: from the of the George prOblem with In addition, o Speed restrictions will be imposed along the above segment; o A bike path will be provided along the same segment to safeguard children in transit to and from a school which ~s situated close to the road;and o Improvements will be made to the intersection of the George Parks and Denali Highways including pavement markings and traffic signals. 1.12.4 -Right-of-Way (**) The 21.3 miles of existing road along the Denali Highway will be upgraded to approximately the aforementioned standards.The present alignment is such that any realignment required srlOuld be possible within the existing easement. 851011 A-1-24 ) I j j 1 I ) I ) } I j I 1 j I ) j I I J J The majority of the new road will follow terrain and soil types which allow construction using side borrow techniques,resulting in a minimum of disturbance to areas away from the alignment.A berm type cross section will be formed,with the crown of the road being approximately two to three feet above the elevation of adjacent ground.To reduce the visual impact,the side slopes will be flattened and covered with excavated peat material.A 200-foot right-of-way will be sufficient for this type of construction.Although sidehill cuts must be minimized to avoid the effects of thawing permafrost and winter icing on the section of road running parallel to Deadman Creek,in isolated spots of extensive sidehill cutting it may be necessary to exceed the 200-foot width. 1.12.5 -Construction Schedule (**) The overall schedule for the Watana development relies heavily on the ability to move supplies,materials and equipment to the site as soon as possible after the start of project construction. The selected plan involves the least mileage of new road construction and follows relatively level,open terrain in comparison with the alternative routes in the two other corridors.Consequently,construction of this route has the highest probability of meeting schedule and hence affords the least risk of project delay.It has been estimated that it will take approximately 1.5 years to construct the access road.One year will be required for completion and upgrading of the Denali Highway section. 1.13 -Site Facilities (**) 1.13.1 -General (**) The construction of the Watana development will require various facilities to support the construction activities throughout the entire construction period.Following construction,the operation of the Watana hydroelectric development will require certain permanent staff and facilities to support the permanent operation and maintenance program. The most significant item among the site facilities will be a construction camp and village that will be constructed and maintained at the project site.The camp/village will be a largely self-sufficient community housing up to 3,300 people during construction of the project.After Stage I construction is complete,it is planned to demobilize most of the camp facility for later use.The buildings and other items from the camp will be used during construction of Stage III.Other site facilities include contractors'work areas,site power,services, and communications.Items such as power and communications will 851011 A-1-25 I ,l ) J ') I I, ) j i ----l I 1 I I, J I j I I Permanent facilities requieed will include a permanent town or small community for approximately 130 staff members and their families.Other permanent facilities will include maintenance buildings for use during subsequent operation of the power plant. J De required operations. aid room. for construction operations independent of camp The same will be true regarding a hospital or first- 1 J A conceptual plan for the permanent town L8 spown on Plate F37. 1.13.2 -Temporary Camp and Village (**) The proposed location of the construe tion camp and village will be on the north bank of the Susitna River near Deadman Creek, approximately six miles northeast of the Watana Dam.The north side of the Susitna River was chosen because the main access will be from the north and south-facing slopes can be used for siting the structures.The location is shown in Plate F34. The construction camp will consist of woodframe dormitories with mess halls,recreational buildings,bank,post office,fire station,warehouses,hospital,offices,etc.The camp will accommodate approximately 3,000 workers. The village,accommodat ing approximately 300 fami lies,wi 11 be grouped around a service core containing a school,gymnasium, stores,and recreation area. The village and construction camp areas will be sepaeated to provide a buffee zone between areas.The hospital will serve both the main camp and village. The camp location will be separated from the work areas by approximately three miles.Travel time to the work area will generally be less than 15 minutes. The camp/village will be constructed in stages to accommodate the peak work force.The facilities have been designed for the peak work force plus 10 percent foe turnover.The tuenover will include allowances for overlap of workers and vacations.The conceptual layouts for the camp and village are presented on plates F36 and F37. (a)Site Preparation (**) Both the camp and the village areas will be cleared and in certain areas filter fabric may be installed and granular material placed over it for building foundations.At the 851011 A-1-26 I \ J I I ) I -) 1 i ! ) 1 'i I ~ (b) village site,selected areas will be left with trees and natural vegetation intact.Topsoil stripped from Borrow Site D will be utilized to reclaim camp and village sites. Both the construction camp and the village site have been selected to provide well-drained land. Facili ties (**) Construction camp buildings will consist largely of factory-built modules assembled on site to provide the various facilities required.The modules will be fabricated complete with heating,lighting and plumbing services, interior finishes,furnishings,and equipment.Larger structures such as the central utilities building, warehouses and hospital will be pre-engineered,steel- framed structures with metal cladding. J 1.13.3 -Permanent Town (**) The permanent town which will be utilized during construction ~s designed around a small lake for aesthetic purposes.The permanent town will consist of permanently constructed buildings.The various buildings in the permanent town are as follows: o Single family dwellings; o Multi-family dwellings; o Hospital; o School; o Fire station; a A town center will be constructed and will contain the following:1)a recreation center;2)a gymnasium and swimming pool;and,3)a shopping center. 1.13.4 -Site Power and Utilities (**) (a)Power (**) A 34.5 kV transmission line from the Cantwell substation will follow the Denali Highway and the access road to Watana for servicing during the Stage I construction activities. Two transformers will be installed at a Watana substation to reduce the line voltage to the desired voltage levels. The peak demand during the peak camp population year is estimated at 20 MW for the camp/village and four MW for construction requirements.The distribution system in the camp/village and construction area will be 4.16 kV. 851011 A-l-27 I , -I 1 i ! , 1 I~ -\ Power for the permanent town and during Stage III construction,will be supplied by station service system after the power plant is in operation. (b)\vater (**) The water supply system will provide for potable water and fire protection for the camp/village and selected contractors'work areas.The estimated peak population to be served will be 3,338 (2,315 in the camp and 1,023 in the village)• The principal source of water will be Deadman Creek,with a backup system of wells drawing on ground water.The water will be treated in accordance with the U.S.Environmental Protection Agency's (EPA)primary and secondary requirements,and Drinking Water Standards of the State of Alaska,Department of Environmental Conservation (ADEC). J ~l J (c) A system of pumps and storage reservoirs will provide the necessary system capacity.The distribution system will be contained withinutilidors constructed using plywood box sections integral with the permawalks. Wastewater (**) A wastewater collection and treatment system will serve the camp/village.One treatment plant will serve the camp/village.Gravity flow lines with lift stations will be used to collect the wastewater from all of the camp and village facilities.The "in-camp"and "in-village" collection systems will be run through the utilidors so that the collection system will be protected from freezing. The chemical toilets located around the construction site will be serviced by sewage trucks,which will discharge directly into the sewage treatment plant.The sewage treatment system will be a biological system with lagoons designed to meet Alaska ADEC and Federal EPA standards.The sewage plant will discharge its treated effluent through a force main to Deadman Creek.All treated sludge will be disposed in a solid waste sanitary landfill. The location of the treatment plant is shown in Plate F37. The location was selected to avoid unnecessary odors in the camp. 851011 A-1-28 I J I I: ) ) I ) [ -1 ~ I I \ J J -=1 ) 1.13.5 -Contractors'Area (**) The on-site contractors facilities will require office,shop,and general work areas.Partial space required by the contractors for fabrication shops,maintenance shops,storage or warehouses, and work areas will be located between the main camp and the dam site road. 1.14 -Relict Channel (***) A relict channel exists on the north bank of the Watana reservoir approximately 2,600 feet upstream from the dam.This channel runs from the Susitna River gorge to Tsusena Creek,a distance of about 1.5 miles.The surface elevation of the lowest saddle is approximately 2,210.Depths of up to 454 feet of glacial deposits have been identified.The maximum average hydraulic gradient along any flow path in the buried channel from the edge of the Stage I pool (el.2,000)to Tsusena Creek is approximately two percent.Tsusena Creek at the relict channel outlet area is at least 120 feet above the natural river level.There are several surface lakes within the channel area,and some artesian water is present in places.Zones of permafrost have also been identified throughout the channel area. To insure the integrity of the rim of the Watana reservoir and to control losses due to potential seepage,a number of conditions have been evaluated.Study types include settlement of the reservoir rim, subsurface flows,permafrost and liquefaction during earthquakes. 1.14.1 -Surface Flows (**) Based on information gained from past exploration programs,tne relict channel soils are either dense or cohesive and as such are not deemed to be subject to settlement resulting tor seismic shaking.Therefore the low ground surface in the relict channel area will more than provide adequate freeboard as it is 185 feet above the Stage I dam crest which is el.2,025. 1.14.2 -Subsurface Flows (**) During Stage I,the potential for progressive piping and erOSlon in the area of discharge into the Tsusena Creek will be controlled by the placement of properly graded granular materials to form a filter blanket over any zones of emergence.Further field investigations will be carried-out to fully define critical areas,and only such areas will be treated.Subsequent to Stage I,the relict channel will receive continuous monitoring of the outlet area for a lengthy period after reservoir filling to ensure that a state of equilibrium is established with respect to permafrost and seepage gradients in the buried channel area. 851011 A-1-29 I ~, I r I I -/ 1 i I \ J l I ,l 1.14.3 -Permafrost (**) Thawing of permafrost will occur in portions of the relict channel area.This thawing will have minimum impact on subsurface flows and ground settlement.Although no specific remedial work is foreseen;flows,groundwater elevation,and ground surface elevation in the buried channel area will be carefully and continuously monitored by means of appropriate instrumentation systems and any necessary maintenance work carried out to maintain freeboard and control seepage discharge. 1.14.4 -Liquefaction (***) Underground information compiled to date indicates that the buried channel area is filled with outwash,glacial till and lacustrine deposits.Initial evaluations,outlined in the original license application indicated concern in regard to the upper outwash deposits because they did not appear dense enough to resist seismic shaking without experiencing considerable loss in stability. The most likely prospects for liquefaction are saturated foundations consisting of fine grained,poorly graded, cohesionless deposits (sands and silts),that are not laterally confined and are loose or only moderately dense.Based on the Winter 1983 Exploration Program (HE 1983)and all other assembled data,an assessment of the liquefaction potential of the reli.ct channel area indicates the deposits are ei.ther well graded,dense to very dense or cohesive and therefore have very low potential for liquefaction.Consequently no remedial measures are currently considered necessary as a precautLon against the effects of liquefaction. Further geotechnical studies will be carried out during Stage I design to fully define the extent and characteristics of the materials in the relict channel.Should this information indicate a potential problem,provisions will be made for treatment to cover the conditions identified. 1.14.5 -Remedial Work Influence on Construction Schedules (***) Relict channel remedial treatment construction work,if necessary,will have practically no impact on the Watana Dam construction schedule.Because the relict channel work will be located in proximity to Borrow Site D,some coordination will be required between these two operations.Once this coordination has been accomplished,dam construction and the relict channel work can proceed concurrently. 851011 A-I-30 I'_I I 1 I t I I -I 1 851011 1.14.6 -Relict Channel Treatment (***) During future design investigations,additional boreholes and inspection trenches will be employed to further delineate the relict channel foundation.The area will be studied during Borrow Site D excavation.The area will also be thoroughly monitored by observation devices during the Stage I reservoir filling to assess actual hydrological conditions in the relict channel.In response tQ the unlikely event that construction remedial measures are considered necessary following those observations and data assessment,a positive remedial treatment such as a downstream toe drain will be employed. A-1-31 I I I I I I r I r -I -I I j ,( I J 1 l 2 -RESERVOIR DATA -WATANA STAGE I (**) The Watana Reservoir,at normal operating level of 2,000 feet (mean sea level),will be approximately 39 miles long with a maximum width of approximately two miles.The total water surface area at normal operating level is 20,000 acres.The minimum reservoir level will be 1,850 feet during normal operation,resulting in a maximum drawdown of 150 feet.The reservoir will have a total capacity of 4.3 million acre-feet,of which 2.4 million acre-feet will be live storage. 851011 A-2-1 J I I I ,( I ( ! 1 I 1 I I, J 1 3 -TURBINES AND GENERATORS -WATANA STAGE L (**) 3.1 -Unit Capacity (**) The Watana powerhouse wi 11 have four generating uni ts,each with a maximum generator output of 125 MW in Stage I corresponding to the maximum normal reservoir level (elevation 2,000)and a corresponding net head of 537 feet.The Stage I turbines will be designed to operate in Stage III without modification,and the turbines and generating units will therefore be capable of higher outputs when the head is raised in Stage III.Unit characteristics including generator outputs are described in Table F.I. The net head on the plant will vary from 384 feet to approximately 537 feet in Stage 1.This wi 11 increase to a maximum of 719 feet in Stage III with a corresponding increase in generating capacity. The turbine design net head has been established at 590 feet to meet the operating requirements of Stage I and Stage III. The generator rating has been selected as 223 MVA with a 90 percent power factor to match with the maximum turbtne output of 204 MW under a net head of 719 feet at the third stage.The generator output is assumed to be 98%of the turbine output at full load. 3.2 -Turbines (***) The turbines will be of the vertical-shaft Francis type with steel spiral casing and a steel lined concrete elbow-type draft tube.The draft tube will comprise a single water passage without a center pier. The output of the turbine will be 150 MW at 590 feet design net head. Maximium and minimum net operating heads on the units will be 537 feet and 384 feet,respectively.The full gate output of each turbine will be approximately 128 MW at 537 feet net head and approximately 66 MW at 384 feet net head.For study purposes,the best efficiency (best-gate) output of the turbines has been assumed as 85 percent of the full gate turbine output. Each turbine will be provided with a l2.5-foot diameter straight-flow type butterfly valve.These guard valves will be located within the powerhouse,just upstream of the turbines. 3.3 -Generators (**) 3.3.1 -Type and Rating (**) Each of the four generators in the Watana powerhouse will be of the vertical-shaft,overhung type directly connected to a vertical Francis turbine. There will be two generators per transformer bank,with each transformer bank comprising three single-phase transformers.The 851011 A-3-1 j 1 r ( i i ( I r l 1 ( I i ( I I J generators will be connected to the transformers by isolated phase bus through generator circuit breakers. Each generator will be provided with a high initial response static excitation system.The units will be controlled from the Watana surface control room,with local control facility also provided at the powerhouse floor.The units will be designed for black start operation. The generators will be rated as follows to accomodate Stage I and Stage III operating conditions: 1 -( Rated Capacity Rated Power Rated Voltage Synchronous Speed Inertia Constant Transient Reactance Short Circuit Ratio Efficiency at Full Load 223 MVA,0.9 power factor 200 MW 15 kV,3 phase,60 Hertz 257 rpm 3.5 MW-sec/MVA 32 percent (calculated) 1.1 (minimum) 98 percent (minimum) The generators will be of the air-cooled type,with water-to-air heat exchangers located on the stator periphery.The ratings given above are for a temperature rise of the stator and rotor windings not exceeding 75°C with cooling air at 40°C in accord- ance witn ANSI C50.10,General Requirements for Synchronous Machines. The generators will operate successfully at rated kVA,frequency, and power factor at any voltage not more than five percent above or below rated voltage. 3.3.2 -Unit Dimensions (**) Approximate dimensions and weights of the principal parts of the generator are given below: Stator pit diameter Rotor diameter Rotor length (without shaft) Rotor weight Total weight 38 feet 24 feet 7 feet 385 tons 740 tons 851011 It should be noted that these are approximate figures and they will vary between manufacturers. 3.3.3 -Generator Excitation System (**) The generator will be provided with a high initial response type static excitation system supplied with rectified excitation A-3-2 j I I i I i I r 1 1 I I I \ l i J 1 -\ -I ~l power from transformers connected directly to the generator terminals.The excitation system will be capable of supplying 200 percent of rated excitation field (ceiling voltage)with a generator terminal voltage of 70 percent.The power rectifiers will have a one-third spare capacity to maintain generation even during failure of a complete rectifier module. The excitation system will be equipped with a fully static voltage regulating system maintaining output from 30 percent to 115 percent,within +0.5 percent accuracy of the voltage setting. Manual control will be possible at the excitation board located on the powerhouse floor,although the unit will normally be under remote control. 3.4 -Governor System (0) The governor system which controls the generating unit will include a governor actuator and a governor pumping unit.A single system will be provided for each unit.The governor actuator will be the electric hydraulic type and will be connected to the computerized station con- trol system. 851011 A-3-3 J I I I I I I [ i 1 r I ! 1 I I J 1 4 -APPURTENANT MECHANICAL AND ELECTRICAL EQUIPMENT - WATANA STAGE I (**) 4.1 -Miscellaneous Mechanical Equipment (**) 4.1.1 -Powerhouse Cranes (*) Two overhead traveling-bridge type powerhouse cranes will be installed in the powerhouse.The cranes will be used for: a Installation of turbines,generators,and other powerhouse equipment;and o Subsequent dismantling and reassembly of equipment during maintenance overhauls. Each crane will have a main and auxiliary hoist.The combined capacity of the main hoist for both cranes will be sufficient for the heaviest equipment lift,which will be the generator rotor, plus an equalizing beam.A crane capacity of 200 tons has been established.The auxiliary hoist capacity will be about 25 tons. 4.1.2 -Draft Tube Gates (**) Draft tube gates will be provided to permit de\oJatering of the turbine water passages for inspection and maintenance of the turbines.The draft tube gate openings (one opening per unit) will be located in the surge chamber.The gates will be of the bulkhead type,installed under balanced head conditions using the surge chamber crane.Four sets of gates have been assumed for the four units.Each gate will be 20 feet wide by 10 feet high. 4.1.3 -Surge Chamber Gate Crane (*) A Crane will be installed in the surge chamber for installation and removal of the draft tube gates as fNell as the tailrace tunnel intake stoplogs.The crane will have a capacity of approximately 30 tons. 4.1.4 -Miscellaneous Cranes and Hoists (**) In addition to the powerhouse cranes and surge chamber gate crane,the following cranes and hoists will be provided in the power plant: o A five-ton monorail hoist in the transformer gallery for transformer and SF6 gas-insulated equipment maintenance; 851011 A-4-1 J 1 1 [ i I ! f I J 1 -\ =j a A four-ton monorail hoist in the circuit breaker gallery for handling the generator circuit breakers; a Small overhead jib or A-frame type hoists in the machine shop for handling material;and a A-frame or monorail hoists for handling miscellaneous small equipment in the powerhouse. 4.1.5 -Elevators (**) Access and service elevators will be provided for the power plant as follows: a An access elevator from the control buildings to the powerhouse; a A service elevator 1n the powerhouse serV1ce bay;and o Inspection hoists in the SF6 gas insulated bus shaft. 4.1.6 -Power Plant Mechanical Service Systems (**) The power plant mechanical service systems installed under Stage I wi 11 provide for future expansion under Stage Ill.The various systems common to all units will be designed to permit the necessary increase incapacity and the extension of piping and duct work to provide service to units added in Stage III. (a)Station Water Systems (0) The station water systems will include the water intake, cooling water systems,turbine seal water systems,and domestic water systems.The water intakes will supply water for the various station water systems in addition to fire protection water. (b'Fire Protection System (**) The power plant fire protection system will consist of fire hose stations located throughout the powerhouse,transfor- mer gallery,and bus tunnels;sprinkler systems for the transformers and the oil rooms;C02 systems for the genera- tors;and portable fire extinguishers located in strategic areas of the powerhouse and transformer gallery.A fire protection head tank has been indicated adjacent to the access shaft,250 feet above the powerhouse roof level,but a pumping system may be adopted during detailed design. 851011 A-4-2 I ( J I i I I I I ( I 1 I r ! I I J (c)Compressed Air Systems (**) Compressed alr will be required In the powerhouse for the following: o Service air; o Instrument air; o Generator brakes; o Draft tube water level depression; o 345 kV SF6 gas insulated circuit breakers; o Generator circuit breakers;and o Governor accumulator tanks. I (d) For the preliminary design,two compressed air systems have been assumed:a 100-psig air system for service air,brake air,and air for draft tube water level depression;and a 1,000-psig high~pressure air system for governor air. During detailed plant design,separate air systems for 345 kV SF6 gas insulated circuit breakers and generator clrcuit breakers will be provided. Oil Storage and Handling (**) Facilities will be provided for replacing oil in the transformers and for topping-off or replacing oil in the turbine and generator bearings and the governor pumping system.For preliminary design purposes,two oil rooms have been included,one in the transformer gallery and one in the powerhouse service bay.An oil separation sump has been indicated adjacent to unit/drainage sumps. (e)Drainage and Dewatering Systems (**) The drainage and dewatering systems will consist of: o A unit dewatering and filling system o A clear water discharge system o A sanitary drainage system. The unit dewatering and filling systems will consist of two sumps each with two dewatering pumps and associated piping and valves from each of the units.To prevent station flooding,the sump will be designed to withstand maximum tailwater pressure.A valved draft tube drain line will connect to a dewatering header running below the drainage gallery.The spiral case will be drained by a valved line connecting the spiral case to the draft tube.It will be necessary to insure that the spiral case drain valve is not open when the spiral case is pressurized to headwater level. The dewatering pump discharge line will discharge water into 851011 A-4-3 I I I 1 J the surge chamber.The general procedure for dewatering a unit will be to close the butterfly guard valve,drain the penstock to tailwater level through the unit,then open the draft tube and spiral case drains to dewater the unit. Because the drainage dewatering header is below the bottom of the draft tube elbow,it will be possible to completely dewater the draft tube through the dewatering header. Unit filling to tailwater level will be accomplished from the surge chamber through the dewatering pump discharge line (with a bypass around the pumps)and then through the draft tube and spiral case drain lines.Alternatively,the unit can be filled to tailwater level through the draft tube drain line from an adjacent unit.Filling the unit to headwater pressure will be accomplished by opening the butterfly guard valve. (f)Heating,Ventilation,and Cooling (**) The heating,ventilation,and cooling system for the underground power plant will be designed primarily to maintain suitable temperatures for equipment operation and to provide a safe and comfortable atmosphere for operating and maintenance personnel.The access shaft,vent shaft, and the access tunnel will be utilized for air circulation. The power plant will be located in mass rock which has a constant year-round temperature of about 40°F.Considering heat given off from the generators and other equipment,the primary requirement will be for air cooling.Initially, some heating will be required to offset the heat loss to the rock,but after the first few years of operation an equilibrium will be reached with a powerhouse rock surface temperature of about 60 to 70°F. 4.1.7 -Surface Facilities Mechanical Service Systems (*) The mechanical services at the control center on the surface will include: o A heating,ventilation,and a~r conditioning system for the control room; o Domestic water and washroom facilities;and o A halon fire protection system for the control room. Domestic water will be supplied from the powerhouse domestic water system,with pumps located in the powerhouse and piping up through the access shaft.Sanitary drainage from the control 851011 A-4-4 i 1 r I I J -\ center wili drain to the sewage treatment plant tn the powerhouse through piping in the access tunnel. The standby generator building will have the following services: o A heating and ventilation system; o A fuel oil system with buried fuel oil storage tanks outside the building,and transfer pumps and a day tank within the building;and o A fire protection system of the carbon dioxide or halon type. 4.1.8 -Machine Shop Facilities (0) A machine shop and tool room will be located in the powerhouse service bay area with sufficient equipment to take care of all normal maintenance work at the plant,as well as machine shop work for the larger components at Devil Canyon. 4.2 -Accessory Electrical Equipment (**) The accessory electrical equipment described tn this section includes the f 0 11 owi ng: o Main generator step-up i5/345 /i.73 kV transformers, o Isolated phase bus connecting the generator and transformecs, o Generator circuit breakers, o 345 kV SF6 busses from the transformer terminals to the tcansmission yard, o Control systems of the entire hydro plant complex,and o Station service auxiliary ac and de systems. Other equipment and systems described include grounding,lighting sys- tem,and communications. The main equipment and connections in the power plant are shown in the single line diagram,plate F30.The arrangement of equipment in the powerhouse,transformer gallery,and vertical shaft is shown on Plates F25 through F27. 4.2.i -Transformers and HV Connections (**) Six single-phase transformers and one spare transformer wiil be located in the transformer gallery.Each bank of three single-phase transformers will be connected to two generators through generator circuit breakers by an isolated phase bus located in individual bus tunnels.The H.V.bushings of the single-phase transformers will be of the SF6 to oil type.These 851011 A-4-5 J j I J 1 ) I I I , I J -[ I I bushings will be star-connected by the SF6 compressed gas- insulated (eGI)bus system at 345 kV and to the gas-insulated switchgear (GIS).Two sets of eGI busses ~"ill be carried from the GIS to the surface through a single vertical shaft.Each set of busses consists of three single-phase busses sized to have sufficient capacity to carry the entire plant output.The buses will be terminated at the surface SF6-to-air entrance bushings where they will be connected to the two overhead transmission lines.The vertical shaft will be nine feet 1.0.and about 530 feet high and will also contain the control and power cables between the powerhouse and the surface to the underground facilities. The area at the surface,above the cable shaft,will accommodate conventiona 1 open'-a i r equi pment such as surge arres te rs,coupling capacitor voltage transformers,line traps and take-off structures for overhead transmission lines. 4.2.2 -Main Transformers (**) The six single-phase transformers (three transformers per group of two generators)and one spare transformer will be of the two- winding,oil-imme rsed,forced-oi I water-cool ed (FOW)type,wi th ratings and electrical characteristics as follows: Rated capacity High voltage winding Basic insulation level (BIL) of H.V.winding Low voltage winding Basic insulation level (BIL) of L.V.winding Taps H.V.winding at rated MVA Transformer impedance 150 MVA 345 /1.73 kV,Grounded Y 1300 kV 15 kV,Delta 95 kV 2-1/2%and 5%above and 2-1/2%and 5%below rated voltage 15 percent The temperature rise above ambient (40 0 e)will be 55°e for the windings for continuous operation at the rated MVA. To minimize fire hazard,each single-phase transformer will be separated by fire walls and will be provided wi th an automat ic deluge system. 4.2.3 -Generator Isolated Phase Bus (**) The isolated phase bus main connections will be located between the generator,generator circuit breaker,and the transformer. 851011 A-4-6 I 'I J I I 1 J 1 I ,I Tap-off connections will be made to the surge protection and potential transformer cubicle,excitation transformers,and station service transformers.Bus duct ratings are as follows: Rated current,amps Short circuit current momentary,amps Short circuit current, symmetrical,amps Basic insulation level,kV (BIL) Generator Connection 9,000 240,000 150,000 110 Transformer Connection 18,000 240,000 150,000 110 The bus conductors will be designed for a temperature rise of 65°C above 40°C ambient.The short circuit ratings are tentative, and will depend on detailed analysis in the design stage. 4.2.4 -Generator Circuit Breakers (**) The generator circuit breakers will be enclosed a~r circuit breakers suitable for mounting in line with the generator isolated phase bus ducts.They are rated as follows: Rated Current Voltage Breaking capacity, symmetrical,amps 9,000 Amps 24 kV class,3-phase,60 Hertz 150,000 l The short circuit rating is tentative and will depend on detailed analysis in the design stage. 4.2.5 -This section deleted. 4.2.6 -Control Systems (**) (a)General (*) A Susitna Area Control Center will be located at Watana to control both the Watana and the Devil Canyon power plants. The control center will be linked through the supervisory system to the Central Dispatch Control Center at willow as described in Exhibit B,Section 3.6. The supervisory control of the entire Alaska Railbelt system will be at the Central Dispatch Center in willow.Using digital computers a high level of automation will be sought. However,complete computerized control of the Watana and Devil Canyon power plants will not be used.Independent operator controlled local-manual and local-auto operations 851011 A-4-7 I i j =1 I , j J I I J l (b) will still be possible at Watana and Devil Canyon power plants for testing/commissioning or during emergencIes.The control system will be designed to perform the following functions at both power plants: o Start/stop and loading of units by operator; o Load-frequency control of units; o Reservoir/water flow control; o Continuous monitoring and data logging; o Alarm annunciation;and o Man-machine communication through visual display units (VDU)and console. In addition,the computer system will be capable of retrieval of technical data,design criteria,equipment characteristics and operating limitations,schematic diagrams,and operating/maintenance records of the unit. The Susitna Area Control Center will be capable of completely independent control of the Central Dispatch Center in case of system emergencies.Similarly it will be possible to operate the Susitna units in an emergency from the Central Dispatch Center,although this should be an unlikely operation considering the size,complexity,and impact of the Susitna generating plants on the system. The Watana and Devil Canyon plants will be capable of "black start"operation in the event of a complete blackout or collapse of the power system.The control systems of the two plants and the Susitna Area Control Center complex will be supplied by a non-interruptible power supply. Unit Control System (*) The unit control system will permit the operator to initiate an entire sequence of actions by pushing one button at the control console,provided all preliminary plant conditions have been first checked by the operator,and system security and unit commitment have been cleared through the central dispatch control supervisor.Unit control will be designed to: a Start a unit and synchronize it with the system, a Load the unit, a Stop a unit, a Operate a unit as spinning reserve (runner in aIr with water depressed in turbine and draft tube),and o Operate as a synchronous condenser (runner in air as above)• 851011 A-4-8 ] I ) J I 1 I ,I I ) i -' J (c)Computer-Aided Control System (0) The computer-aided control system at the Susitna Area Control Center at Watana will provide for the following: o Data acquisition and monitoring of units (MW,MVAR, speed,gate pos'ition,temperatures,etc.); o Data acquisition and monitoring of reservoir headwater and tailwater levels; o Data acquisition and monitoring of electrical system voltage and frequency; o Load-frequency control; o Unit start/stop control; o Unit loading; o Plant operation alarm and trip conditions (audible and visual alarm on control board,full alarm details on VDU on demand'); o General visual plant operation status on VDU and on large wall mimic diagram; o Data logging,plant operation records; o Plant abnormal operation or disturbance automatic recording;and o Water management (reservoir control). (d)Local Control and Relay Boards (0) Local boards will be provided at the powerhouse floor equipped with local controls,alarms,and indications for all unit control functions.These boards will be located near each unit and will be utilized mainly during testing, commissioning,and maintenance of the turbines and generators.They will also be utilized as needed during emergencies if there is a total failure of the remote or computer-aided control systems. (e)Load-Frequency Control (0) The load-frequency system will provide remote control of the output of the generator at Watana and Devil Canyon from 851011 A-4-9 i J I 1 I-I 1 ) J the central dispatch control center through the supervisory and computer-aided control system at Watana.The basic method of load-frequency control will use the plant error (differential)signals from the load dispatch center and will allocate these errors to the power plant generators automatically through speed-level motors.Provision will be made in the control system for the more advanced scheme of a closed-loop control system with digital control of generator power. The control system will be designed to take into account the digital nature of the controller-timed pulses as well as the inherent time delays caused by the speed-level motor runup and turbine-generator time constants. 4.2.7 -Station Service Auxiliary AC and DC Systems (**) (a)Auxiliary AC System (**) The station service system will be designed to achieve a reliable and economic distribution system for the power plant to satisfy the following requirements: o Station service power at 480 volts will be obtained from two 2,000 kVA auxiliary transformers connected directly to the generator circuit breaker outgoing leads of Units 1 and 3; o Surface auxiliary power at 34.5 kV will be supplied by two separate 7.5/10 MVA transformers connected to the generator leads of Units 1 and 3; o Station service power will be maintained even when all units are shut down and the generator circuit breakers are open; o 100 percent standby transformer capacity will be available; o "Black start"capability will be provided for the power plant in the event of total failure of the auxiliary supply system,and 500 kH·emergency diesel generators will be automatically started to supply the power plant with auxiliary power to the essential services to enable start-up of the generators. The main ac auxiliary switchboard will be provided with two bus sections separated by bus-tie circuit breakers.Under normal operating conditions,the station-service load 1S divided and connected to each of the two-end incoming 851011 A-4-l0 ) j J ,I I I I I I I -I ,I 1 i i ) i , f J transformers.In the event of failure of one end supply, the tie breakers will close automatically.If both end supplies fail,the emergency diesel generator will be automatically connected to the station service bus. Each unit will be provided with a unit auxiliary board supplied by separate feeders from the two bus section feeder from the two bus section of the main switchboard interlocked to prevent parallel operation.Separate ac switchboards will furnish the auxiliary power to essential and general services in the power plant. The unit auxiliary board will supply the auxiliaries necessary for starting,running,and stopping the generating unit.These supplies will include those to the governor and oil pressure system,bearing oil pumps,cooling pumps and fans,generator circuit breaker,excitation system,and miscellaneous pumps and devices connected with unit opera- tion. The 34.5 kV supply to the surface facilities will be distributed from a 34.5 kV switchboard located in the surface control and administration building.Power supplies to the power intake and spillway as well as the lighting systems for the access roads and tunnels will be obtained from the 34.5 kV switchboard. The two 2000 kVA,15,000-480 volt stations will have service transformers of the three-phase,dry-type,sealed gas-filled design.The two 7.5/10 MVA,15-34.5 kV transformers will be of the three-phase oil-immersed OA/FA type. Emergency diesel generators,each rated 500 kW,will separately supply the 480 volt and 34.5 kV auxiliary switchboards during emergencies.Both diesel generators will be located in the surface control building. An uninterruptible high security power supply will be provided for the computer control system. (b)DC Auxiliary Station Service System (*) The dc auxiliary system will supply the protective relaying, supervisory,alarm,control,tripping and indication circuit in the power plant.The generator excitation system will be started with "flashing"power from the dc battery. The dc auxiliary system will also supply the emergency lighting system at critical plant locations. 851011 A-4-l1 I J ) I I I 1 l r j I ] I i J 4.2.8 -Grounding System (0) The power plant grounding system will consist of one mat under the power plant,one mat under the transfonner gallery,risers, and connecting ground wires.Grounding grids will also be included in each powerhouse floor. 4.2.9 -Lighting System (*) The lighting system in the powerhouse will be supplied from 480- 208/120 volt lighting transformers connected to the general ac auxiliary station service system.An emergency lighting system will be provided at the power plant and at the control roam at all criticalopet'ating locations. 4.2.10 -Communications (0) The power plant will be furnished with an intet'nal communications system,including an automatic telephone switchboard system.A communication system will be provided at all powerhouse floors and galleries,transformer gallery,access tunnels and cable shafts,power intake structures,draft tube gate area,main spillway,dam,outlet facilities,and em~rgency release facilities. 4.3 -SF6Gas-Insulated 345 kv Substation (GIS)(***) The substation provides switching for the two tt'ansformer banks and two transmission lines.Four cit'cuit breaker positions arranged in a ring bus switching scheme will be provided as shown in the single line diagram,Plate F31.This arrangement provides the desired switching flexibility and reliability of service required by the adopted system reliability criteria.Disconnecting and grounding switches as well as voltage transformers will be provided for each of the four circuits. Since the conventional sut'ge arresters do not have the reach to protect the GIS and transformers,metal-enclosed surge arresters will be provi- ded at the end of the CGI buses. The GIS will consist of two sections.One of the two sections contain three circuit breaker positions for two circuits (line/transformer)and one section contains one circuit breaker position for two circuits (line/transformer).Each of the sections will be installed in the area between the main transformer banks and connected to busses located on the downstream wall of the transformer gallery. Provisions will be made for future extension and c~the ring bus to a breaker-and-a-half switching scheme. 851011 A-4-12 J J \ I 5 -TRANSMISSION FACILITIES FOR WATANA STAGE I (**) 5.1 -Transmission Requirements (0) The purpose of the project transmission facilities will be to deliver power from the Susitna River basin generating plants to the major load centers at Anchorage and Fairbanks.The transmission system is to deliver power to the load centers in an economical and reliable manner. The facilities will consist of overhead transmission lines,under-water cables,switchyards,substations,a load dispatch center,and a communications system.Construction of the transmission Eacilities will be staged to provide reliable operations from each oE the three stages of the development.The design will provide for delivery of power to one substation in Fairbanks,one substation at Willow,and two substations in Anchorage.As the power generated by the Watana Stage I hydroelectric station will be used to serve all the substations noted above,the associated transmission facilities will extend over the full length of the corridor.Later when Devil Canyon Stage II and Watana Stage III are developed,the facilities will be supplemented with additional components along some parts of the corridor. 5.2 -Description of Facilities (0) 5.2.1 -Corridor (0) The corridor that the transmission lines will follow as they leave the generating plants is generally westward,following the Susitna River valley to Gold Creek near the Alaska Railroad route.At Gold Creek,the corridor divides to provide for lines north to Fairbanks and south to Anchorage;in both cases,the corridor generally follows the Railbe1t.However,the lines to Anchorage will leave tne Rai1belt just outside Willow.At this point,the corridor continues in a southerly direction to reach the north shore of Knik Arm.Underwater cables will be installed to cross the Knik Arm.The corridor enters military reserved territory and is constrained to pass near the northern and eastern perimeter of Fort Richardson through the reservation,and finally loops south and west to the site of the existing University substation located some four miles southeast of the center of Anchorage. 851011 A-5-l I J l -1 ( I I ( I i The length of the corridor sections and the nurnbe r of lines contained within them are shown In the followi ng tabl e: r~NUMBER OF 345 kV CIRCUITS Corridor CORRIDOR Length Stage I Stage II Stage III Devel- SECTION Miles Watana Devil Canyon Watana opment l.Watana to Gold Creek 36 2 2 2.Gold Creek to Fai rbanks 185 2 2 3.Gold Creek to Wi 11 ow 79 2 1 3 4.Willow to Knik Arm (Wes t)43 2 1 3 5.Knik Arm Crossing 3 2 1 3 6.Knik Arm to Anchorage 19 2 2 7.D.C.to Gold 3 ..,2'- Creek The physical location of the corridor is shown in a regional contex.t,on plate No.F105,Exhibit F.A schematic diagram of the system is given on Plates No.F96,F97 and F98,of Exhibit F. 5.2.2 -Components (0) At the Watana site,a SF6 gas-insulated 345kV substation (GIS) will be provided.The substation will be located in the transformer gallery.The switching arrangement will be a ring bus which will provide the necessary switching feasibility and reliability.Two sets of SF6 compressed gas-insulated busses will be carried from the GIS to the surface.Each set of busses consists of three single-phase busses sized to have sufficient capacity to carry the entire plant output.The busses will be terminated at the surface,where they will be connected to the two overhead transmission lines (refer to plate F96,Exhibit E). From Watana,two single-circuit 345 kV lines will be built westward to the Gold Creek switching station.From the Watana substation,both lines wi 11 continue in a northwest direction,a distance of approximately two miles crossing Tsusena Creek,then will turn west and share the same general corridor as the \ 851011 A-5-2 J I I I I I I i I t 9 f I ( -( ) j proposed access road all the way to the Devil Canyon dam site. From Devil Canyon,the lines will head in a southwest direction, crossing the Susitna River at river mile 149.8,then will turn westward and follow the proposed railroad extension a distance of approximately six mile~to the Gold Creek switching station.The Gold Creek switching station will be located in an area on the south bank terraces of the Susitna River at approximately river mile 142. The Gold Creek switching station layout will be based on the breaker-and-a-half arrangement.At this station,switching will be provided so that the output of the Watana development can be transmitted partly north along the two lines to Fairbanks and partly to Anchorage along the two lines that run south.Power transmitted in either of these directions will be able to be switched to one line of the pair in the event of an outage on the other.Switching also will allow either of the lines from Watana to supply either Fairbanks or Anchorage,providing complete flexibi Ii ty. Access to the Gold Creek switching station site will be by an 8-mile long all-weather road from the railroad at Gold Creek (refer to Plate F 100,Exhibit F).The two 345 kVsingle-circuit lines to Fairbanks from Gold Creek will share the same right~of-way north,generally following the RailbeH past Chulitna,Cantwell,Denali Park and Healy,sited to the east of the railroad.About 1 mile north of Healy the lines will cross to the west side of the Nenana River and the railroad,continuing northwards for about 14 miles between the Parks Road on the west and the railroad on the east.At this point the lines will recross to the east side of the Nenana River and tne railroad, continuing north to cross the Tanana River about 8 miles east of the town of Nenana,and then will continue northeastward to a point six miles west of Fairbanks at Ester substation,the northern terminal of the 345 kV system. At Ester substation provision will be made to step down the voltage to 138 kV for delivery to the Golden Valley Electric Association.A total of four 150 MVA transformer banks can be installed at the substation site.Switching will be provided at 345 kV to enable the load to be supplied from both or either of the incoming lines.A breaker-and-a-half arrangement will be used.The Ester switchyard will also be provided with switchable 75 MVAR shunt reactors on each of the 345 kV lines for use during line energizing;switching will allow the reactor to be removed from the line if necessary during emergency heavy line loading if one line suffers an outage.For purposes of control of the system static VAR compensation will be required on the 138 kV busses at Ester and will consist of units with +200/-100 MVAR continuous,and +300/-100 MVAR short time ratings.The ratings 851011 A-5-3 l I J I I I ( I ( =1 i I ( --( ) J I 851011 of the VAR control equipment will be confirmed and,if necessary, refined during final design (refer to Plate F99,Exhibit F). Access to the Ester Substation will be provided by an all-weather gravel road linked to the nearby Fairbanks Highway. Two single-circuit 345 kV lines will exit from the Gold Creek switching station in a southwesternly direction following the east bank of the Susitna River past the village of Gold Creek. At this point while the river and the Alaska Railroad continue southwest,the line route will head south departing up to 10 miles to the east from the Railbelt.Approximately 50 miles south of Gold Creek the lines will rejoin the Railbelt near the Kashwitna River.From here the lines will run 6 miles parallel to the Railbelt on the east of the road to reach the Willow switching station.The Willow substation will be sited about 2 miles north of Willow. The Willow switching station will serve a dual function;firstly, it will provide a facility to feed load in the locality at 138 kV.A total of three 75 MVA,three-phase transformers could be installed.Secondly,the station will provide complete line switching through a breaker-and-a-half arrangement.This switching will facilitate line energizing by limiting overvoltages.It will also allow flexibility to isolate a line section that might suffer an outage and to route load through the remaining lines (refer to Plate F10l,Exhibit F).The Willow site access will be provided with an all-weather gravel road about 1 mile long across Willow Creek to the Willow Creek Road. An Energy Management Center will also be located at the Willow substation site.The entire operation of the power generation and transmission system will be controlled from the Center. Remote control will be provided through communications via a microwave system.Existing microwave communications from Anchorage to Willow and from Fairbanks to Healy will be augmented and extended to provide a continuous link between Fairbanks and Anchorage with a spur into the power developments at Devil Canyon and Watana. Two single-circuit 345 kV lines leaving Willow switching station will run due west for about 4 miles,then turn south and cross Willow Creek.The lines will continue in a generally southward direction to cross the Little Susitna River about 25 miles from Willow Creek.At this point the lines will bear in a south- easterly direction for about 15 miles to arrive at the west side of Knik Arm about five and a half miles north of Pt.MacKenzie, adjacent to the site of an existing 230 kV line. A-5-4 I J I I I I I I I I ( 1 r i ( -( J 1 851011 Knik Arm will be crossed by submarine cables buried in the inlet bed.Two circuits will be provided,each consisting of three individual single-phase 345 kV submarine cables.A third cable will contain a spare phase.On each shore a cable termination station will contain disconnect switches,surge arrestors and ground connection devices required for operation of the cable facility.Another feature of the terminals will be an arrangement of an upper level bus which will allow for temporary connections to bring into contingency service a spare single phase cable.The spare cable can replace any cable which might suffer accidental damage. In the bed of the inlet,the circuits will be physically separ- ated into three back-filled trenches;two will contain three single-phase cables making up the two main circuits,the third will contain the spare phase.Each trench will be separated from the other by approximately 1/4 mile with a similar distance being maintained from the existing 230 kV crossing.The separation in the navigation area will be achieved by curving the trenches in plan on the foreshore of the inlet.This arrangement oEsepar- ating the circuits will provide an added measure of protection against multiple circuit damage due to navigation in the inlet. Access to the east and west terminals will be by gravel road built along the transmission line right-of-way to the nearest public access about 3 miles distant on the east side and 12 miles on the west. On the southeasterly side of KnikArm the line route will pass through the Fort Richardson military reservation.The route will follow a path parallel to an existing 230 kV line.Beyond the Knik Arm substation it will consist of two 345 kV circuits. Because of the restricted width available for right-of-way there is a requirement to use compact line design techniques. Double-circuit steel pole structures will be designed with extra conservative safety factors to increase reliability against loss of both circuits due to structural failure.Separation of the circuit onto two separate single pole structures using post type insulators to prevent conductor swing will be adopted where right~of-way width permits.From the southeasterly shore of Knik Arm the route will run southeast to the intersection of Glenn and Davis Highways,where it will turn southwesterly following the Glenn Highway on the southeast side,and then pass east of Homesite Park and southwest to the vicinity of the existing Unive~sity substation on Tudor Road. The Knik Arm substation will be located in the general vicinity of the Glen and Davis Highway intersection near where the existing 230 kV and 115 kV lines share the same right-of-way. This facility will allow for a breaker-and-a-half layout with complete flexibility in switching at 345 kV between the incoming and outgoing pairs of lines to cope \~ith possible outage situa- A-5-5 f I \ I ( 851011 tions.Each of the irrcoming lines from Willow will have a switchable 30 MVAR shunt reactor to assist with voltage control during energizing of the line.Also the facility will provide one 75 MVA,three-phase transformer to feed into the U5 kV existing system that passes nearby (refer to Plate Fl02,Exhibit F). The University substation site will represent the southernmost terminal ot the 345 kV transmission facility.The substation will serve as the major distribution point for power from Watana and Devil Canyon into the Anchorage area.Provision will be made for transformation to 230 kV and 115 kV to suit the existing utility systems in the area.At the 230kV level up to four 250 MVA banks of single-phase trans formers ,tIill be accommodated,and at 115 kV two 250 MVA bank of single-phase transformers can be installed.For transient stability,static VAR compensation will be provided on outgoing lines to Anchorage consisting of units with ratings on the 230 kV system of +150/-100 MVAR continuous and +200/-75 MVAR short time;on the US kV system rated at +200/-75 MVAR continuous,and +300/-75 MVAR short time.The ratings of the VAR control equipment will be confirmed and,if necessary,refined in final design (refer to Plate Fl03.Exhibit F).Access to the University substation will be by the existing gravel road directly off Tudor Road. The Applicant has constructed an Anchorage-Fairbanks "Inter tie" projec t (Commonweal th Associates,Inc.1982).Approximately 170 miles of one of the 345 kV lines between Healy and Willow on the Fairbanks to Anchorage corridor has been constructed.This line is built to operate eventually at 345 kV,but is initially being operated at 138 kV.When it is integrated into the Watana transmission system it will operate at 345 kV. 5.2.3 -Right-of-Way (0) The right-of-way for the transmission corridor will consist of a linear strip of land.The width will depend on the number of lines.North of the cable crossing of Knik Arm,the right-of-way will include that area necessary for the additions to the facilities planned in conjunction with the Devil Canyon Stage II and Watana III development.In the sections with two lines,the right-of-way width will be 300 feet;for three lines it will be 400 feet.Between Gold Creek and Devil Canyon,where ultimately four lines will be required,the width will be 510 feet. In the Knik Arm underwater crossing area,the right-of-way will be widened to account for the fact that each circuit of the total development will be separated from the adjacent circuits by a distance of about 1/4 mile,The spare single phase cable will A-5-6 I I J I I i [ I ! i f \ 1 ( i ( j J 851011 also be 1/4 mile from the other cables.The width of the bed affected by the crossing will be approximately one mile. Southeast of Knik Arm the right-of-way width will be restricted in the military reservation.In this section the right-of-way will be 300 feet from the centerline of an existing 230 kV line. Approximate right-of-way areas to be occupied by the switching and substations are listed below. Area of Right-of-Way (acres) Gold Creek Switchyard •...•....•........•.16 Fairbanks (Ester)Subs tat ion .•.•.........25 Willow Substation .•......••....•...•.....25 Knik Arm Substation......................15 Anchorage (University)Substation.......•45 Rights-of-way for permanent access to switchyard and substations will be required linking back to a public road or in some cases rail access~These rights~of-way will be 100 feet wide. 5.2.4 -Transmission Lines (0) Access to the transmission line corridor will be via trails from existing access routes at intermittent points along the corridor. The exact location of these trails will be established in the final design phase.Within the transmission corridor itself an access strip 25 feet wide will run along the entire length of the corridor,except at areas such as major river crossings and deep ravines where an access strip would not be utilized for the movement of equipment and materials. The conductor capacity for the lines will be in the range of 1,950 MCM;this can be provided in several ways.Typical of these isa phase bundle consisting of two 954 MCM "Rail"(45/7) Aluminum Conductor Steel Reinforced (ACSR)or a single 2,156 MCM "Bluebird"(84/1 n ACSR conductor,bo th of which provide comparable levels of corona and radio noise within normally accepted limits.The single "Bluebird"conductor attracts less load under wind or ice loadings and avoids the need to provide the space damper devices required for a bundled phase.The single conductor is stiffer and heavier to handle during stringing operations,although this will tend to be balanced out due to the extra work involved in handling the twin bundle. Selection of the optimum conductor arrangement will be made in final design.The conductor will be specified to have a dull finish treatment to reduce its visibility at a distance.The A-5-7 I ( J I \ I ! I ( I ( "( I J 851011 conductor capacity between Knik Arm and University will be 2,700 MCM per phase to handle the output of Devil Canyon without an additional circuit in this section of the route. Two overhead ground wires will be provided the full length of the line.These will consist of 3lB-inch diameter galvanized steel stands.The arrangement will be based on a shielding angle of 15 degrees over the outer phases;this will provide protection against lightning strikes to the line.More refined studies of the lightning performance of the line will be made during final design to confirm the arrangement outlined above. Vibration control devices will be required on both the conductors and the ground wire.Stockbridge-type dampers on single wires and spacer dampers with an elastometer damping element are expected to be most suitable. Conductor suspension and dead-end assemblies will be detailed according to "corona free"design and prototype tested to check that corona and radio interference are below nuisance levels when operating at elevations of up to 3,500 feet.Insulators will be standard porcelain or glass disc type suspension units.A chain of 18 units is expected to be sufficient to provide acceptable flashover performance of the line.The configuration will be "M" type with vertical strings on the outside phases and a "V"string supporting the center phase. The transmission structures and foundations that serve to support the conductors and ground wires will be designed for a region where foundation movement due to permafrost and annual freeze-thaw cycling is common.Of the structural solutions that have proved successful in similar conditions,all utilize an arrangement of guy cables to support the structure.All depend upon the basic flexibility inherent in guyed structures to resist effects of foundation movement.For tangent and small angle applications the guyed type of structure such as the guyed "V", guyed "Y",guyed delta and the guyed portal are the most common economical arrangements.The guyed "X"design has been selected for use on the 345 kV Intertie (1)and is therefore a prime candidate for consideration on the Watana lines.Experience gained during the Intertie project will be used in the final structure design (cefer to Plate Fl04,Exhibit F). Structures for larger angle and dead-end applications will be in the form of individual guyed masts,one for each phase. Individual guyed masts will also be used for lengths of line that are judged to be in unusually hazardous locations due to exposure terrain is extremely rugged.All structures will utilized a "weathering"steel which matures over several years to a dark A-5-8 I \ J \ 1 I i ( I ) J -1 851011 brown color which is considered to have a more aesthetically pleasing appearance than galvanized steel or aluminum (refer to Plate F 104,Exhibit F). Foundations for structures will utilize driven steel piles in unstable soil conditions.In better soils steel grillage foundations will be used and set sufficiently deep to avoid the effects of the freeze-thaw cycle.Rock footings will employ grouted rock anchors with a minimum use of concrete to facilitate winter construction.Foundations for cantilever pole type structures will be large diameter cast-in-place concrete augered piles.Several types of guy anchor will be available for use; they include the screw-in helix type,the grouted bar earth anchor,driven piles and grouted rock anchors.Selection of the most economical solution in any given situation will depend on the site specific constraints including soil type,access problems and expected guy load.Foundation sites will be graded after installation to contour the disturbed surface to suit the existing grades.Tower grounding provisions will depend upon the results of soil electrical resistivity measurements both prior to and during construction.Continuous counterpoise may be required in sections where rock is at or close to the surface;it also may be required in other areas of high soil resistance.The counterpoise will take the form of two galvanized steel wires remaining at a shallow bury parallel to and under the lines. These will be connected to each tower and cross connected between Lines in the right-of-way.Elsewhere,grounding will be installed in the form of ground rods driven into the soil adjacent to the towers. 5.2.5 -Switching and Stations (0) The physical location of the stations and the system single line diagram is shown on Plate FIOS and F96,97,98 respectively,of Exhibit F.The single line diagram and layout of the individual stations are contained on Plates F99 through FI03 of Exhibit F. The construction access to all sites will be over the route of the permanent access provided for each location.Any grading of the sites will be carried out on a balanced cut-and-fill basis wherever possible.Equipment will be supported on reinforced concrete pad-and-column type footings with sufficient depth-of-bury to avoid the active freeze-thaw layer.Backfill immediately around footing will be granular to avoid frost heave effects. Light equipment may be placed on spread footings if movements are not a significant factor in operational performance. A-5-9 I I J I I I \ f I I 1 ( I -I ) J 851011 The station equipment requirements are determined by the breaker- and-a-half arrangement adopted for reasons of reliability and security of operation.One and one-half breakers will be needed for each line or transformer circuit termination.The trans- former capacities are determined by the load requirements at each substation.Control and metering provisions will cater to the plan for remote operation of all the facilities in normal circumstances.Protective relaying schemes for the 345 kV system will be in accordance with conventional practices,using the general philosophy of dual relaying and the local backup principle. The station layouts are based on conventional outdoor design with a two-level bus which will result in a relatively low profile to the station.This will assist in limiting the visual impact of the stations and make the most of any available neutral buffers. Although they will be remotely controlled,all stations will be provided with a control building;in larger stations an additional relay building will be provided.A storage building will also be provided for maintenance purposes.Each station will have auxiliary power at 480 V;the normal 480 V ac power will be supplied from the tertiaries on the autotransformers or the local utility.The willow station will include the Energy Management Center and the headquarters of the system maintenance group. 5.2.6 -Cable Crossing (0) The cable crossing will consist of two 345 kV circuits each comprising three individual 2,000 MCM single-phase submarine cables;in addition a spare phase cable will be provided.Each circuit will be buried in the inlet bottom,the three cables of the circuit sharing the same trench.Beyond the foreshore area it is anticipated that cables can be buried by a combination of dredging and ploughing as the bed materials are reported to be soft.At each shore,gravel deposits are expected to be encoun- tered so that conventional excavate-and-fill methods are more probable with work being performed from barges in the tidal zone. The centerline of each circuit will be routed on the foreshore to 6btain a physical separation of approximately 1/4 mile between circuits and the spare phase;a similar spacing will be main- tained from the existing 230 kV circuit which runs adjacent to the crossing site. On each side of the arm a terminal yard will be provided to contain the disconnect switches,surge arrestors,and grounding for the cables as well as the cable terminals.The yards will have bus arrangements which will permit the spare phase to be brought into service by installation of temporary bus connections. A-5-l0 ! I J I -1 I j I =J-I I i i -I \ J 5.2.7 -Dispatch Centers -Energy Management Centers and Communications (0) The operation of the transmission facility and the dispatch of power to the load centers will be controlled from a central dispatch and Energy Management System (EMS)center.It has been proposed that the center be located at Willow since a suitable site could be developed at the Willow switching station site. The location of the center could alternatively be at one of the otherkey~oints along the line route.University substation could be considered in final design studies if close proximity to an existing major center of population is thought to be a major advantage in siting.The center will operate in conjunction with northern and southern area control systems in Fairbanks and Anchorage which would control generation in those two areas.The generation at the Susitna hydroelectric sites would be controlled at the Watana power facility.The Energy Management Center would orchestrate the overall operation of the system by request to the three local generation control centers for action and direct operation of the Gold Creek switching station and the four 345 kV switching and substations along the transmission system. The system communications requirements will be provided by means o·f a microwave system.The system will be an enlargement of the facility being provided for the operation of the Intertie between Healy and ~villow.Communications into the hydroelectric plants will be by a microwave extension from the Gold Creek switching station. 5~3 -Construction Staging (0) Watana will require staged development of transmission facilities to Fairoanks and Anchorage.Stage I includes the following: Substations Watana Gold Creek (Southbound) Willow Knik Arm University (Anchorage) Gold Creek (Northbound) Fairbanks Line Section Watana to Intertie switchyard near Gold Creek Switchyard to Willow Willow to Knik Arm Knik Arm Crossing Knik Arm to University Gold Creek to Healy Healy to Fairbanks Number of Circuits 2 211 2 2 2 211 2 _1/'Circuit 1S the existing Anchorage-Fairbanks Intertie 851011 A-5-11 1 I J I 1 I -I I I I j 9 I I 1 -I ',I I=, ! The transmission will consist of two circuits from \.]atana to the load centers.The conductor for the sections from Watana to Knik Arm and Watana to Fairbanks will consist of bundled 2 x 954 kcmil,ACSR.The section between Knik Arm and University will employ bundled 2 x 1351 kcmil,ACSR.The submarine cable crossing will consist of two cir- cuits.The cable will be single conductor,345 kV self-contained oil- filled.For project purposes,the cable size will be 500 mm 2 .A size of up to 1,500 mm 2 may be installed if duty requirements are increased. For reliability,a spare cable will be included on a standby basis. The Matanuska Electric Association will be serviced from the Willow and Knik Arm substations via step-down transformers to suit the local volt- age.Chugach Electric Association and Anchorage Municipal Light and Power will be serviced through the University substation in Anchorage. Golden Valley Electric Association will be serviced through the Ester substation at Fairbanks. 851011 A-5-l2 I I J I ] 9 I I i ( I I J 6 -PROJECT STRUCTURES -DEVIL CANYON STAGE II (**) This section describes the various components of the Devil Canyon de- velopment,including diversion facilities,emergency release facili- ties,main dam,primary outlet facilities,reservoir,main spillway, saddle dam,power intake,penstocks,and the powerhouse complex, including turbines,generators,mechanical and electrical equipment, switchyard structures,and equipment and project lands.A summary of project parameters is presented in Table A.l. A description of permanent and temporary access and support facilities is also included. 6.1 -General Arrangement (**) The Devil Canyon reservoir and surrounding area are shown on Plate FJ9. the site layout in relation to main access facilities and camp facilities is shown on Plate FlO.A more detailed arrangement of the various site structures is presented in Plate F40. The Devil Canyon Dam will form a reservoir approximately 26 miles long with a surfac~area of 7,800 acres and a gross storage capacity of 1,100,000 acre-feet at el.1,455,the normal maximum operating level. The operating level of the Devil Canyon reservoir is controlled by the tailwater level of the upstream Watana development.The maximum water surface elevation during flood conditions will be 1,466.The minimum operating level of the reservoir will be 1,405,providing a live storage during normal operation of 350,000 acre-feet. The dam will be a thin arch concrete structure with a crest elevation of l,46J (not including a J.O-foot parapet)and maximum height of 646 feet.The dam will be supported by mass concrete thrust blocks on each abutment.On the south bank,the lower bedrock surface will require the construction of a substantial thrust block.Adjacent to this thrust block,an earth-and rockfill saddle dam will provide closure to the south bank.The saddle dam will be an earth and rockfill embank- ment generally similar in cross section to the ~.jatana Dam.The dam will have a nominal crest elevation of 1,470 with an additional two feet of overbuild for potential settlement.The max~mum height above foundation level of the dam is approximately 245 feet. During construction,the river will be diverted by means of a single 35.5-foot diameter concrete-lined diversion tunnel on the south bank of the river. A power intake on the north bank will consist of an approach channel excavated in rock leading to a reinforced concrete gate structure. From the intake structure four 20-foot diameter concrete-lined penstock tunnels will lead to an underground powerhouse complex housing four units with Francis turbines and synchronous generators. 851011 A-6-l I I J I 'I I -I I I I I j I I I j -j I I J Access to the powerhouse complex will be by means of an unlined access tunnel approximately 3,200 feet long as well as by a 950-foot deep vertical access shaft.The turbines will discharge to the river by means of a single 38-foot diameter tailrace tunnel leading from a surge chamber downstream from the powerhouse cavern.A separate transformer gallery just upstream from the powerhouse cavern will house twelve singlephase 15/345 kV transformers.The transformers will be connected by 345 kV single-phase,oil-filled cable through a cable shaft to the switchyard at the surface. Outlet facilities consisting of seven individual outlet conduits will be located in the lower part of the main dam.These will be designed to discharge all flood flows of up to the estimated 50-year flood with Watana in place.Each outlet conduit will have a fixed-cone valve similar to those provided at Watana to dissipate energy and minimize undesirable nitrogen supersaturation in the flows downstream.The spillway will also be located on the north bank.As at Watana,this spillway will consist of an upstream ogee control structure with three vertical fixed-wheel gates and an inclined concrete chute and flip bucket designed to pass a maximum discharge of 309,000 cfs.This spillway,together with the outlet facilities,will be capable of discharging the PMF without overtopping the dam. 6.2 -Arch Dam (**) The Devil Canyon Dam will be located at the Devil Canyon gorge,r1ver~ mile 152,approximately 32 river-miles downstream from Watana.The arch dam will be located at the upstream entrance of the canyon. The dam will be a thin arch concrete structure 646 feet high,with a crest length-to-height ratio of approximately two,and designed to withstand dynamic loadings from intense seismic shaking.The proposed hei 5 ht of the dam is well within precedent. 6.2.1 -Foundations (**) Bedrock is well exposed along the canyon walls,and the arch dam will be founded on sound bedrock.In local areas approximately 20 to 40 feet of weathered and/or loose rock will be removed beneath the dam foundation.All bedrock irregularities will be smoothed out beneath the foundation to eliminate high stress concentrations within the concrete.During excavation the rock will also be trimmed as far as is practical to increase the symmetry of the centerline profile and provide a comparatively uniform bearing stress distribution across the dam.Areas of deteriorated dikes and the local areas of poorer quality rock will be excavated and supplemented with dental concrete. The foundation will be consolidation grouted over its entire area,and a double grout curtain up to 300 feet deep will run 851011 A-6-2 1 I J j I I -) I ) ) I 1 / ) ) 1 I I j I j 851011 beneath the dam and its adjacent structures as shown in Plate F47.Grou~ing will be done from a system of galleries which will run through the dam and into the rock.Within the rock these galleries will also serve as collectors for drainage holes which will be drilled just downstream of the grout curtain to intercept any seepage passing through the curtain. 6.2.2 -Arch Dam Geometry (*) The canyon is V-shaped below el.1,350.Sound bedrock does not exist above this level on the south abutment and an artificial abutment will be provided up to crest el.1,463 in the form of a massive concrete thrust block designed to take the thrust from the upper arches of the dam.A corresponding block will be formed on the north abutment to provide as symmetrical a profile as possible bordering the dam and to give a syrrunetrical stress distribution across the faces of the horizontal arches. Two slight ridges will be formed by the rock at both abutments. The arch dam will abut the upstream side of these such that the plane of the contact of the horizontal arches is generally normal to the faces of the dam.An exception will be in the lower portion of the dam where the rock in the upstream corners will be retained in order to decrease the amount of excavation. The dam will bear direc tly on the rock foundation over the entire length of the contact surface.The bedrock at the foundation will be excavated to remove all weathered material and further trimmed to provide a smooth line to the foundation,thus avoiding abrupt changes in the dam profile and consequent stress concentrations. The dam will be a double curvature structure with a cupola shape of the crown cantilever defined by vertical curves of approximate ly l,352-foot and 893-foot radii.The horizontal arches are based on a two-center configuration with the arches prescribed by varying radii moving along two pairs of centerlines.The shorter radii of the intrados face cause a broadening of the arches at the abutment,thus reducing the contact stresses.The dam reference plane is approximateLy central to the floor of the canyon and the two-center configuration assigns longer radii to the arches on the wider north side of the valley,thus providing comparable contact areas and central angles on both sides of the arches at the concrete/rock interface.The longer radii will also allow the thrust from the arches to be directed more into the abutment rather than parallel to the river.The net effect of this two-center Layout will be to improve the syrrunetry of the arch stresses across the dam. A-6-3 l j J _I I I -I j I I ! I i I ~ -j 1 .i The crown cantilever will be 643 feet high.It will be 20 feet thick at the crest and 90 feet at the base,a base width-to-height ratio of 0.140.The radii of the dam axis at crest level will be 699 feet and 777 feet for the south and north sides of the dam,respectively.The central angles vary between 53°at elevation 1,300 and 10°at the base for the south side of the arch,and 57°to 10°for the north side.The dam crest length is 1,260 feet and the ratio of crest length to height for the dam is 1.96 (thrust blocks not included).The volume of concrete in the dam is approximately 1.3 x 10 6 cubic yards. 6.2.3 -Thrust Blocks (*) The thrust blocks are shown on Plate F46.The massive concrete block on the south abutment is 113 feet high and 200 feet long. It will be formed to take the thrust from the upper part of the dam above the existing sound rock level.It will also serve as a transition between the concrete dam and the adjacent rockfill saddle dam.The inclined end face of the block will abut and seal against the impervious saddle dam core and be enveloped by the supporting rock shell. The l13-foot high,l25-foot long thrust block formed high on the north abutment at the end of the dam,adjacent to the spillway control structure,will transmit thrust from the dam through the intake control structure and into the rock. 6.3 -Saddle Dam (**) The saddle dam at Devil Canyon,which is of similar configuration as the Watana Dam,will be of earth and rockfill construction and will consist of a compacted core protected by fine and coarse filters upstream and downstream.The outer shells will consist of rockfill material.A typical cross section is shown on Plate F49 and described below. 6.3.1 -Typical Cross Section (*) The thickness of the impervious core at any section will be slightly more than 0.5 times the head of water at that section. Minimum core/foundation contact will be 50 feet,requiring flaring of the cross section at the abutments. The upstream and downstream filter zones are sized to provide protection against possible piping through transverse cracks that could occur because of settlement or resulting from internal displacement during a seismic event. 851011 A-6-4 ,) 1 ) -I I ) I I i I 9 1 j I I I Protection against wave and ice action on the upstream slope will consist of a layer of larger quarried rock accomplished by rock raking the outer 40 feet of the fill. The estimated volumes of material needed to construct the saddle dam are: o core material o fine filter material o coarse filter material o rockfill material 140,000 cubic yards 150,000 cubic yards 160,000 cubic yards 1,500,000 cubic yards 851011 The saturated sections of both shells will be constructed of compacted clean rockfill to minimize pore pressure generation and ensure rapid dissipation during and after a seismic event.The lower section of the downstream shell,due to a unique combination of bedrock and topographic elevations,may become saturated by natural runoff or dam seepage.During design the cost of a major drainage system to prevent this occurrence will be weighed against the added cost of processing the materials for the lower portion of the fill.Since pore pressures cannot develop in the unsaturated upper section of the downstream shell, the material in that zone will be unprocessed rockfill from surface or underground excavations. 6.3.2 -Crest Details and Freeboard (**) A parapet 3.0 feet high will'be constructed on the crest of the arch dam to provide a freeboard of 11.0 feet. The highest reservoir level will be at e1.1,465.6 under PMF conditions.The normal maximum pool elevation will be at el. 1,455. The typical crest detail for the saddle dam is shown 1n Plate F50. A minimum saddle dam freeboard of four feet will be provided for the PMFj hence,the nominal crest of the saddle dam will be at el.1,470.In addition,an allowance will be made for potential settlement of the rockfill shells.The constructed crest elevations of the saddle dam will be 1,470 at the abutments, rising in proportion to the total height of the dam to e1.1,472 at the maximum section.Under normal operating conditions,the freeboard will be 15 feet. 6.3.3 -Grouting and Pressure Relief System (**) The rock foundation will be improved by consolidation grouting over the core contact area and by a grouted cutoff along the A-6-5 i j \ --I I I ) I' I 9 I, I i I I 1 centerline of the core.The cutoff at any location will extend to a depth in the range of 0.7 of the water head at that location,as shown on Plate F47. A grouting and drainage tunnel will be excavated in bedrock beneath the dam along the centerline of the core and will connect with a similar tunnel beneath the adjacent concrete arch dam and thrust block.Pressure relief and drainage holes will be drilled from this tunnel,and seepage from the drainage system will be discharged through the arch dam drainage system to ultimately exit downstream below tailwater level. 6.3.4 -Instrumentation (*) Observation devices will be installed within all parts of the dam to provide monitoring during construction as well as during operation.Instruments for measuring internal vertical and horizontal displacements,stresses and strains,and total and fluid pressures,as well as surface monuments and markers similar to those proposed for the Watana Dam,will be installed. 6.4 -Diversion (**) 6.4.1 -General (*) Diversion of the river flow during construction will be through a single concrete-lined diversion tunnel on the south bank.The tunnel will have a horseshoe-shaped cross section with a major dimension of 35.5 feet.It will be 1,490 feet in length.The diversion tunnel plan and profile are shown on Plate F5l. The tunnel is designed to pass a flood with a return frequency of 1:25 years routed through the Watana reservoir.The peak flow that the tunnel will discharge will be approximately 43,000 cfs. The maximum water surface elevation upstream of the cofferdam will be el.944. 6.4.2 -Cofferdams (**) The upstream cofferdam will consist of a zoned earth and rockfill embankment (see Plate F52).The diversion dike will be constructed to elevation 915 based on a low water elevation of 910 and will consist of quarry-run rock fill.When the diversion dike is completed,a slurry wall cutoff will be constructed to minimize seepage into the main dam excavation.Final details of this cut-off will be determined following further investigations to define the type and properties of river alluvium.The abutment areas will be excavated to sound rock prior to placement of any cofferdam material. 851011 A-6-6 i ) J ,i I -l I I, I , I ! I I ,) ! I J l 851011 The cofferdam,from elevation 915 to 947,will be a zoned embankment consisting of an impervious core,fine and coarse upstream and downstream filters,and rock shells with larger stone on the upstream face.The downstream cofferdam will be constructed from el.860 to 898,with a slurry wall cutoff to bedrock. The upstream cofferdam crest elevation will have a three-foot free-board allowance for settlement and wave runup.Under the proposed schedule,the Watana development will be operational when this cofferdam is constructed.In a cold winter,ice may form between RM 176 and the cofferdam.The diversion tunnel is designed to pass this ice without ponding,therefore a freeboard allowance for ice is not included in the cofferdam design. 6.4.3 -Tunnel Portals and Gates (*) A gated concrete intake structure will be located at the upstream end of the tunnel (see Plate F53).The portal and gate will be designed for an external pressure (static)head of 250 feet. Two 30-foot high by IS-foot wide water passages will will be formed in the intake structure,separated by a central concrete pier.Gate guides will be provided within the passages for the operation of 30-foot high by IS-foot wide fixed-wheel closure/control gates. Each gate will be operated by a wire rope hoist in an enclosed housing,and will be designed to operate with a 75-foot operating head (el.945). Stoplog guides will be installed in the diversion tunnel to permit dewatering of the diversion tunnel for plugging operations.The stoplogs will be in sections to facilitate relatively easy handling,with a mobile crane using a follower beam. 6.4.4 -Final Closure and Reservoir Filling (*) Upon completion of the Devil Canyon Dam to a height sufficient to allow ponding to a level above the outlet facilities,the intake gates will be partially closed,allowing for a discharge of minimum environmental flows while raising the upstream water level.Once the level rises above the lower level of discharge valves,the diversion gates will be permanently closed and discharge will be through the 90-inch diameter fixed-cone valves in the dam.The diversion tunnel will be plugged with concrete and curtain grouting performed around the plug.Construction will take approximately I year.During this time the reservoir will not be allowed to rise above el.1,135 unless a flood A-6-7 ! l J .I exceeding the outlet works capacity occurs.In this case the water level will be allowed to rise as needed to store the flood. 6.5 -Outlet Facilities (**) The primary function of the outlet facilities is to provide for dis- charge in conjunction with the power facilities,of routed floods with up to 1:50 years recurrence period at the Devil Canyon Reservoir. This will require a total discharge capacity of 42,000 cfs.The use of fixed-cone valves will ensure that downstream erosion will be minimal and nitrogen supersaturation of the releases will be reduced to acceptable levels,as in the case of the Watana development.A further function of these releases is to provide an emergency drawdown for the reservoir,should maintenance be necessary on the main dam or low level submerged structures,and also to act as a diversion facility during the latter part of the construction period. The outlet facilities will be located in the main dam,as shown on plate F48,and will incorporate seven fixed-cone discharge valves set in the lower part of the arch dam. 6.5.1 -Outlet (*) The fixed-cone type discharge valves will be located at two elevations:the upper group,consisting of four 102-inch diameter valves,will be set at el.1,050,and the lower group of three 90-inch diameter valves will be set at elevation 930.The valves will be installed nearly radially (normal to the dam centerline)with the points of impact of the issuing jets staggered as shown in Plate F48. The fixed-cone valves will be installed on individual conduits passing through the dam,set close to the downstream face,and protected by upstream ring follower gates located in separate chambers within the dam.Provisions will be made for maintenance and removal of the valves and gates.The gates and valves will be linked by a 20-foot high gallery running across the dam and into the left abutment,where access will be provided by means of a vertical shaft exiting through the thrust block.Although secondary access will be provided via a similar shaft from the north abutment,primary access and installation are both from the south side. The valve and gate assemblies will be protected by individual trashracks installed on the upstream face.The racks will be removable along guides running on the upstream dam face.A travelling gantry crane will be used for raising the racks. Guides will be installed for the installation of bulkhead gates, if required,at the upstream face.The bulkhead gates will be handled by the travelling gantry crane. 851011 A-6-8 j I ( I ( l I J I l 851011 6.5.2 -Fixed-Cone Valves (*) The 102-inch diameter valves operating at a gross head of 405 feet and the 90-inch diameter valves operating at a head of 525 feet are within current precedent considering the valve size and the static head on the valve.The valves will be located in individually heated rooms and will be provided with electric jacket heaters installed around the cylindrical sleeve of each valve.The valves will be capable of year-round operation, although winter operation is not contemplated.Normally,when the valves are closed,the upstream ring follower gates will also be closed to minimize leakage and freezing of water through the valve seats. The valves will be operated remotely by two hydraulic operators. Operation of the valves will be from either Watana or by local operation. 6.5.3 -Ring Follower Gates (*) Ring follower gates will be installed upsiream of each valve. The ring follower gates will have nominal diameters of 102 and 90 inches and will be of welded or cast steel construction.The gates will be designed to withstand the total static head under full reservoir. The design and arrangement of the ring follower gates will be as for Watana. 6.5.4 -Trashracks (*) A steel trashrack will be installed at the upstream entrance to each water passage to prevent debris from being drawn into the discharge valves.The bar spacing on the racks will be approxi- mately six inches.Provision will be made for monitoring head loss across the racks. 6.5.5 -Bulkhead Gates (*) The bulkhead gates will be installed only under balanced head conditions using the gantry crane.The gates will be 13 feet and 11 feet square for the upper and lower valves,respectively. Each gate will be designed to withstand full differential head under maximum reservoir water level.One gate for each valve size has been assumed.The gates will be stored at the dam crest level. A-6-9 ( \ J I I \ I ! j l ( ! ! -, \ J J -I ! 1 A temporary cover will be placed in the bulkhead gate check at trash rack level to prevent debris from getting behind the trashracks. The bulkhead gates andtrashracks will be handled by an electric traveling gantry type crane located on the main dam crest at el.1,463.The crane and lifting arrangement will have provision for lowering a gate around the curved face of the dam. 6.6 -Spillway (**) The spillway at Devil Canyon will be located on the north side of the canyon (see Plate F54).The upstream control structure will be adjacent to the arch dam thrust block and will discharge down an inclined concrete-lined chute constructed on the steep face of the canyon wall.The chute will terminate in a flip bucket which will direct flows downstream and into the river. The Devil Canyon spillway in combination with the outlet works is designed to pass the routed PMF from Watana during both Stages II and III.The maximum outflows from the spillway would be 351,000 cfs and 333,000 cfs in Stages II and III,respectively.The maximum water levels would be el.1,465.6 and el.1,463.1 in Stages II and III. These levels will be below the top of the parapet wall on the concrete arch section of the the dam (el.1,466.0).The capacity of the spillway and outlet works is approximately 280,000 cfs at a water level of el.1,456.0.This exceeds the 95 percent upper one sided confluence level for the 10,000 year flood inflow of 262,000.Thus the project can release the 10,000 year flood without the water level exceeding el.1,456.0. 6.6.1 -Approach Channel and Control Structure (*) The approach channel will be excavated to a depth varying between 100 feet and 176 feet in the bedrock with a width of just over 130 feet and an invert elevation of 1,375. The control structure,as shown in Plate F55,will be a three-bay concrete structure set at the end of the channel.Each bay will incorporate a 6l-foot high by 48-foot wide gate on an agee-crested weir and,in conjunction with the other gates,will control the flows passing through the spillway.The gates will be radial type operated by individual hydraulic hoists. A gallery will be provided within the mass concrete weir from which grouting can be carried out and drain holes can be drilled as a continuation of the grout curtain and drainage beneath the main dam.The main access route will cross the control structure deck upstream of the gate tower and bridge structure. 851011 A-6-l0 I d I I I ( f ( ! l ( ( i l \ I J 851011 6.6.2 -Spillway Chute (**) The spillway chute will be excavated in the steep north face of the canyon for a distance of approximately 900 feet, terminating at el.1,000.The chute will taper uniformly over its length from 176 feet at the upstream end to 150 feet downstream.The chute will be concrete-lined with invert and wall slabs anchored to the rock. The velocity at the lower end of the chute will be approximately 150 ft/sec.In order to prevent cavitation of the chute surfaces,air will be introduced into the discharges.As at Watana,air will be drawn in along the chute via an underlying aeration gallery and offshoot ducts extending to the downstream side of a raised step running transverse to the chute. An extensive underdrainage system will be provided to ensure adequate underdrainage of the spillway chute and stability of the structure.This system is designed to prevent excessive uplift pressures due to reservoir seepage under the control structure and from groundwater and seepage through construction joints from the high velo~ity flows within the spillway itself. The dam grout curtain and drainage system will be extended under the spillway control structure utilizing a gallery through the rollway.A system of box drains will be installed for the entire length of the spillway under the concrete slab.To avoid block- age of the system by freezing of the surface drains,a 3D-foot deep drainage gallery will also be constructed along the entire length of the spillway.Drain holes from the surface drains will intersect the gallery.To ensure adequate foundation quality for anchorage,consolidation grouting will be undertaken to a depth of 20 feet.Drainage holes drilled into the base of the high rock cuts will ensure increased stability of the excavation. 6.6.3 -Flip Bucket (**) The spillway chute will terminate in a mass concrete flip bucket founded on sound rock at el.970,approximately 100 feet above the river.Detailed geometry of the curve of the flow surface of the bucket will be confirmed by means of hydraulic model tests. A grouting/drainage gallery will be provided within the bucket. The jet issuing from the bucket will be directed downstream and parallel to the river alignment. 6.6.4 -Plunge Pool (0) The impact area of the issuing spillway discharge will be limited to the area of the river surface downstream to prevent A-6-l1 ( J I I I r ( f ( ( 1 l ! i \ I J excessive erosion of the canyon walls.This will be done by appropriate shaping of the flow surface of the flip bucket on the basis of model studies.Over this impact area the alluvial material in the riverbed will be excavated down to sound rock to provide a plunge pool in which most of the inherent energy of the discharges will be dissipated,although some energy will already have been dissipated by friction in the chute and in dispersion and friction through the air. 6.7 -Emergency Spillway (This section deleted) 6.8 -Power Facilities (*) 6.8.1 -Intake Structure (*) The intake structure will be located on the north side of the canyon.Four sets of intake openings will be provided.The intake openings and power tunnels will be grouped in pairs so that each turbine may be supplied by water passing through two sets of intake openings.Each set of intake openings will consist of an upper and lower opening.The reservoir level will vary between elevations 1,455 (in the winter)and 1,405 in the summer of low flow years.In most years the reservoir water level is expected to stay above el.1,435 all year.When the reservoir is at its maximum level the water will normally be withdrawn from the top opening in each set.As the reservoir is drawn down in August and September,the lower opening will be used.Each opening will be provided with a set of trashracks and a provision for placing sliding steel closure shutters downstream from the intake opening.The trash racks and shutters will be removed for maintenance. The intake will be located at the end of an approximately 200-foot long unlined approach channel.The overburden in this area is estimated to be approximately ten feet deep.The excavation for the intake structure will require four tunnel portals on 60-foot centers.Rock pillars approximately 32 feet wide by 38 feet deep will separate the portals. 6.8.2 -Intake Gates (*) Each of the four powerhouse intake tunnels will have a single fixed-wheel intake gate 20 feet wide by 24 feet high.The gates will have an upstream skinplate and seal and will be operated by hydraulic or wire rope hoists located in heated enclosures immediately below deck level.The gates,which will normally close under balanced head conditions to permit 851011 A-6-12 ( ( J f I I I ( ( I ( 1 ! ! ( I I ! 851011 J -I 1 dewatering of the penstock and turbine water passages for turbine inspection and maintenance,will also be capable of closing under their own weight with full flow conditions and maximum reservoir water level in the event of runaway of the turbines.A heated air vent will be provided at the intake deck to satisfy air demand requirements when the intake gate is closed with flowing water conditions. 6.8.3 -Intake Bulkhead Gates (*) A bulkhead gate consisting of two sections will be provided for closing the intake openings.The gate will be used to permit inspection and maintenance of the intake gate and intake gate guides.The gates will be raised and lowered under balanced head conditions only. 6.8.4 -Intake Gantry Crane (*) A 50-ton capacity electrical traveling gantry crane will be provided on the intake deck at elevation 1,466 for handling the trashracks,and intake bulkhead gates and for servicing the intake gate equipment. 6.9 -Penstocks (**) The power plant will have four penstocks,one for each unit.The maxi- mum static head on each penstock will be 638 feet,as measured from normal maximum operating level (el.1,455)to centerline distributor level (el.817).An allowance of 35 percent has been made for pressure rise in the penstock under transient conditions,giving a maximum head of 861 feet.Maximum extreme head (including transient loadings) corresponding to maximum reservoir flood level will be 876 feet. The penstock tunnels are fully concrete-lined.In addition a 250-foot section upstream of the powerhouse which will be steel-lined.The inclined sections of the concrete-lined penstocks will be at 55°to the horizontal. 6.9.1 -Steel Liner (*) The steel-lined penstock will be 15 feet in diameter.The first 50 feet of steel liner immediately upstream of the powerhouse will be designed to resist the full internal pressure.The remainder of the steel liner,extending another 200 feet upstream,will be designed to partially resist the internal pressure together with the rock.Beyond the steel liner,the hydraulic loads will be supported solely by the rock tunnel with a concrete liner. The steel liner will be surrounded by a concrete infill with a minimum thickness of 24 inches.A tapered steel transition will be A-6-13 I J i I I I ( ( i ( ( 1 I I ! -I \ i J 1 provided at the junction between the steel liner and the concrete liner to increase the internal diameter from 15 feet to 20 feet. 6.9.2 -Concrete Liner (*) The thickness of the concrete lining will vary with the design head,with the minimum thickness of lining being 12 inches. The internal diameter of the concrete liner will be 20 feet. 6.9.3 -Grouting and Pressure Relief System (**) A comprehensive drainage system will be installed to protect the underground caverns against seepage from the high pressure penstocks and reservoirs.The system will consist of small diameter boreholes set out in an array to intercept the jointing in the rock.Grouting around the penstocks will also be undertaken. 6.10 -Powerhouse and Related Structures (**) The underground powerhouse complex will be constructed in the north side of the canyon.This will require the excavation of three major caverns (powerhouse,transformer gallery and surge chamber),with in- terconnecting rock tunnels for the draft tubes and isolated phase bus ducts. An unlined rock tunnel will be constructed for vehicular access to the three main rock caverns.A second unlined rock tunnel will provide access from the powerhouse to the foot of the arch dam. Vertical shafts will be required for personnel access by elevator to the underground powerhouse,for oil-filled cable from the transformer gallery,and for surge chamber venting. The draft tube gate gallery and cavern will be located in the surge chamber cavern,above maximum design surge level. The general layout of the powerhouse complex is shown on Plates F63, F64 and F65.The transformer gallery will be located upstream of the powerhouse cavern and the surge chamber will be located downstream of the powerhouse cavern.The spacing between the underground caverns will be fixed so as to be at least 1.5 times the main span of the larger excavation. 6.10.1 -Access Tunnels and Shafts (**) The 3,000-foot long main access tunnel will connect the power- house cavern at el.858 with the canyon access road on the north bank.A secondary access tunnel will run from the main powerhouse access tunnel to the foot of the arch dam for routine 851011 A-6-l4 1 ( J i I I I ( I I I I 1 i 851011 maintenance of the fixed-cone valves.Branch tunnels from the secondary access tunnel will provide construction access to the lower section of the penstocks at el.820.Separate branch tunnels from the main access tunnel will give vehicle access to the transformer gallery at el.896 and the draft tube gate gallery at el.908.The maximum gradient on the permanent access tunnel will be eight percent;the maximum gradient on the secondary access tunnel will be nine percent. The cross section of the access tunnels,which will be dictated by requirements for the construction plant,will be a modified horseshoe shape 35 feet wide by 28 feet high. The main access shaft will be located at the north end of the powerhouse cavern,providing personnel access by elevator from the surface.Horizontal tunnels will be provided from this shaft for pedestrian access to the transformer gallery and the draft tube gate gallery.At a higher level,access will also be available to the fire protection head tank. 6.10.2 -Powerhouse Cavern (*) The main powerhouse cavern is designed to accommodate four verti- cal-shaft Francis turbines,in line,with direct coupling to synchronous generators. The unit spacing will be 60 feet with an additional 110-foot service bay at the south end of the powerhouse for routine maintenance and construction erection.The control room will be located at the north end of the main powerhouse floor.The width of the cavern will be sufficient for the physical size of the generator plus galleries for piping,air-conditioning ducts, electrical cables,and isolated phase bus.The overall size of the powerhouse cavern will be 74 feet wide;360 feet long,and 126 feet high. Multiple stairway access points will be available from the powerhouse main floor to each gallery level.Access to the transformer gallery from the powerhouse will be by a tunnel from the access shaft or by a stairway through each of the four bus tunnels.Access will also be available to the draft tube gate gallery by a tunnel from the main access shaft. A service elevator will be provided for access from the service bay area on the main floor to the machine shop,and the dewatering and drainage galleries on the lower floors.Hatches will be provided through all main floors _for installation and routine maintenance of pumps,valves and other heavy equipment using the main powerhouse crane. A-6-l5 J ] .~ I I I -I 6.10.3 -Transformer Gallery (**) The transformers will be located underground in a separate unlined rock cavern,120 feet upstream of the powerhouse cavern,with four interconnecting tunnels for the isolated phase bus.There will be 12 single-phase transformers with one group of three transformers for each generating unit.For increased reliability,one spare transformer and one spare HV circuit will be provided~The station service transformers and the surface facilities transformers will be located in the bus tunnels. Generator excitation transformers will be located on the main powerhouse floor.The overall size of the transformer gallery will be 43 feet wide,40 feet high,and 446 feet long;the bus tunnels will be 14 feet wide and 14 feet high. High voltage cables will be taken to the surface in two 7.5-foot internal diameter cable shafts,and provision will be made for an inspection hoist in each shaft. Vehicle access to the transformer gallery will be from the south end via the main powerhouse access tunnel.Personnel access will be from the main access shaft or through each of the four isolated phase bus tunnels. 6.10.4 -Surge Chamber (**) A simple surge chamber will be constructed 120 feet downstream of the powerhouse to control pressure fluctuations in the turoine draft tubes and tailrace tunnel under transient load conditions, and on machine start-up.The chamber will be common to all four draft tubes.The overall size of the chamber will be 75 feet wide,240 feet long,and 190 feet high. The draft tube gate gallery and crane will be located in the same cavern,above the maximum anticipated surge level.Access to the draft tube gate gallery will be by a rock tunnel from the main access tunnel.The tunnel will be widened locally for storage of the draft tube gates. The chamber will be an unlined rock excavation with localized rock support as necessary for stability of the roof arch and walls.The guide blocks for the draft tube gates will be of reinforced concrete anchored to the rock excavation by rock bolts. 6.10.5 -Draft Tube Tunnels (*) The orientation of the draft tube tunnels will be 300°.The tunnels will be 19 feet in diameter and steel-and concrete- lined,with the concrete having a thickness of about two feet. 851011 A-6-16 J I ~ r 1 j ! j I I I I l j I J 6.11 -Tailrace Tunnel (*) The tailrace pressure tunnel will convey power plant discharge from the surge chamber to the river.The tunnel will have a modified horseshoe cross section with an internal dimension of 38 feet,and will be concrete-lined throughout with a m1n1mum thickness of 12 inches. The length of the tunnel is 6,800 feet. The tailrace portal site will be located at a prominent steep rock face on the north bank of the river.The portal outlet is rectangular in section,which reduces both the maximum outlet velocity (eight ft/sec) as well as the velocity head losses.Vertical stoplog guides will be provided for closure of the tunnel for tunnel inspection and/or maintenance. 6.12 -Access Plan (**) 6.12.1 -Description of Access Plan (*) Access to the Devil Canyon development will consist primarily of a railroad extension from the existing Alaska Railroad at Gold Creek to a railhead and storage facility adjacent to the Devil Canyon camp area.From here materials and supplies will be distributed using a system of site roads. To provide flexibility of access the railroad extension will be augmented by a road between the Devil Canyon and Watana damsites. The availability of both road and rail access will reduce the schedule and cost risks associated with limited access. This road connection will also be required for travel between Watana and Devil Canyon by the post-construction operation and maintenance personnel who will be stationed at Watana. 6.12.2 -Rail Extension (*) Except for a two-mile section where the route traverses steep terrain alongside the Susitna River,the railroad will climb steadily for 12.2 miles from Gold Creek to the railhead facility near the Devil Canyon camp. Nearly all of the route traverses potentially frozen Basal till on side slopes varying from flat to moderately steep.Several streams are crossed,requiring the construction of large culverts.However,where the railroad crosses Jack Long Creek small bridges will be built to minimize impacts to the aquatic habitat.In view of the construction conditions it is estimated that it will take eighteen months to two years to complete the extension.Therefore construction should start two years prior to commencement of the main works at Devil Canyon. 851011 A-6-17 J I ~ I I j ! ! ! J I I I The railroad extension will be designed in accordance with the parameters set out below: These parameters are consistent with those presently being used by the Alaska Railroad. -I Maximum grade Maximum curvature Design loading 2.5% 10 0 E-72 J 6.12.3 -Connecting Road (**) From the railhead facility at Devil Canyon a connecting road will be built to a high-level suspension bridge approximately one mile downstream of the damsite.The route then proceeds in a north-easterly direction,crosses Devil Creek and swings around past Swimming Bear Lake at an elevation of 3,500 feet before continuing in a southeasterly direction through a wide pass. After crossing Tsusena Creek,the road continues south to the Watana damsite.The overall length of the road is 37.0 miles. In general the alignment crosses good soil types with bedrock at or near the surface.Erosion and thaw settlement problems should not be a problem since the terrain has gentle to moderate slopes which will allow roadbed construction without deep cuts. The connecting road will be built to the same standards and in accordance with the design parameters used for the Watana access road. 6.12.4 -Construction Schedule (**) The 1,790-foot long high-level suspension bridge crossing the Susitna River is the controlling item in the construction schedule,requiring three years for completion.Therefore, access for the start of the main works at the Devil Canyon damsite will utilize the Watana access road. 6.12.5 -Right~of-Way (**) The road and railroad routes mainly traverse terrain with gentle to moderate side slopes,where a right-of-way width of 200 feet will be sufficient.Only in areas of major sidehill cutting and deep excavation will it be necessary to go beyond 200 feet. 6.13 -Site Facilities (*) The construction of Devil Canyon will require various facilities to support the construction activities throughout the entire construction period.Following construction,the planned operation and maintenance 851011 A-6-18 J 1 ~ I I 1 I ) j ] j l i I I ,I I 1 of Devil Canyon will be centered at Watana;therefore,a m~n~mum of facilities at the site will be required to maintain the project during operation. As described for Watana,a camp and construction village will be constructed and maintained at the project site.The camp/village will provide housing and living facilities for 1,900 people during construction.Other site facilities will include contractors'work areas,site power,services,and communications.Items such as power and communications and hospital services will also be required for construction operations independent of camp operations.Electric power will be provided from Watana. 6.13.1 -Temporary Camp and Village (**) A tentative location for the camp/village ~s on the south bank of the Susitna River between the damsite and Portage Creek, approximately 2.5 miles southwest of the Devil Canyon Dam (see plate F70).The south side of the Susitna was chosen because the main access road in this area will be from the south.South- facing slopes will be used for the camp/village location. The camp will consist of woodframe dormitories with modular mess halls,recreational buildings,bank,post office,fire station, warehouses,hospital,offices,etc.The camp will accommodate approximately 1,400 workers. The village,designed for approximately 150 families,will be grouped around a service core containing a school,gymnasium, stores,and recreation area. The two areas will be separated to provide a buffer zone.The hospital will serve both the main camp and the village. l The camp location will proximately one mile. generally be less than be separated from the work areas by ap- Travel time to the work area will 15 minutes. The camp/village will be constructed in stages to accommodate the peak work force.The facilities will be designed for the peak work force plus ten percent for "turnover".The "turnover"will include provisions for overlap of workers and vacations.The conceptual layouts for the camp/village are presented in Plates F72 and F73. Construction camp buildings will consist largely of factory-built modules assembled at site to provide the various facilities required.The modules will be fabricated with heating,lighting, and plumbing facilities,interior finishes,furnishings,and 851011 A-6-19 J I ~ I I I I I I I I I I l I I I ] I I equipment.Modules will be supported on timber cribbing or blocking approximately two feet above grade. Larger structures such as the central utilities building,gym, and warehouses will be pre-engineered steel-framed structures with metal cladding. The various buildings in the camp are identified on Plate F72. 6.13.2 -Site Power and Utilities (**) (a)Power (**) A 345 kV transmission line from Watana and a substation will be in service during the construction activities.Two transformers will be installed at the substation to reduce the line voltage to the desired voltage levels. The peak demand during construction is estimated at 20 MW for the camp/village and four MW for construction requirements.The distribution system for the camp/village will be 4.16 kV. (b)Water (**) The water supply system will serve the entire camp/village and selected contractors'work areas.The water supply system will provide for potable water and fire protection. The estimated peak population to be served will be 1,940 (1,410 in the camp and 530 in the village). The principal source of water will be the Susitna River.-I The water will be treated in accordance with the U.S. I Environmental Protection Agency (EPA)primary and secondary requirements and with Drinking Water Standards of the State of Alaska Department of Environmental Conservation (ADEC). (c)Wastewater (**) One wastewater collection and treatment system will serve the camp/village.Gravity flow lines with lift stations will be used to collect the wastewater from all of the camp and village facilities.The "in-camp"and "in-village" collection systems will be run through the permawalks and utilidors so that the collection system will always be protected from the elements. At the village,an aerated collection basin will be in- stalled to collect the sewage.The sewage will be pumped 851011 A-6-20 -] ) J I I I ] 1 1 I ) l I I , ] 1 I J I J l 851011 from this collection basin through a force main to the sewage treatment plant. Chemical toilets located around the site will be serviced by sewage trucks which will discharge directly into the sewage treatment plant. The sewage treatment system will be a biological system with lagoons.The system will be designed to meet Alaska ADEC and Federal EPA standards.The lagoons and system will be modular to allow for growth and contraction of the camp/village. The location of the treatment plant is shown on Plate F70. The location was selected to avoid unnecessary odors in the camp. The sewage plant will discharge its treated effluent to the Susitna River.All treated sludge will be disposed of in an approved solid waste sanitary landfill. 6.13.3 -Contractors'Area (**) Contractors on the site will require offices,workshops,ware houses,storage areas,and fabrication shops.These will be located on the south side of the Susitna River near the dam site. A-6-21 j I J ,I ) I ] ) j I 1 1 I I I, J 7 -DEVIL CANYON RESERVOIR STAGE II (*) The Devil Canyon reservoir,at a normal operating level of 1,455 feet, will be approximately 26 miles long with a maximum width of approximately 1/2 mile.The total surface area at normal operating level will be 7,800 acres.Immediately upstream of the dam,the maximum water depth will be approximately 580 feet.The minimum reservoir level will be 1,405 feet during normal operation,resulting in a maximum drawdown of 50 feet.The reservoir will have a total capacity of 1,100,000 acre-feet of which 350,000 acre-feet will be live storage. 851011 A-7-1 l I 8 -TURBINES AND GENERATORS -DEVIL CANYON STAGE II (**) 8.1 -Unit Capacity (**) The Devil Canyon powerhouse will have four generating units,each with a maximum output of 173 MW based on the full reservoir level at elevation 1,455 and a corresponding net head of 600 feet.The net head on the plant will vary from 545 feet to 600 feet.Unit characteristics including generator outputs are described in Table F.1. The operating head for rating the unit will be the m~n~mum net head of 545 feet.Rated unit output at this head is 150 MW. The generator rating has been selected as 192 MVA with a 90 percent power factor to match the maximum in turbine output under maximum head. Generator output is assumed to be 98 percent of the turbine output at full load. 8.2 -Turbines (**) The turbines will be of the vertical-shaft Francis type with steel spiral casing and a concrete lined elbow-type draft tube.The draft tube will have a single water passage with no piers. Maximum and minimum net heads on the turbine will be 600 feet and 545 feet,respectively.The full-gate output of the turbines will be about 177 MW at maximum net head and 153 MW at minimum net head.For study purposes,the best efficiency (best-gate)output of the units has been assumed at 85 percent of the full-gate turbine output. 8.3 -Generators (0) The four generators in the Devil Canyon powerhouse will be of the vertical-shaft,overhung synchronous directly connected to the vertical Francis turbines. The generators will be similar in construction and design to the Watana generators.The general features described in Section 3.2 for the stator,rotor,excitation system,and other details also will apply for the Devil Canyon generators. The rating and characteristics of the generators will be as follows: 851011 Rated Capacity: Rated Power: Rated Voltage: 192 MVA,0.9 power factor 170 MW 15 kV,3 phase,60 Hertz A-8-1 I I j I J i I l I I I [ -) Synchronous Speed: Inertia Constant: Short Circuit Ratio: Efficiency at Full Load: 8.4 -Governor System (0) 225 rpm 3.5 MW-Sec/MVA 1.1 (minimum) 98 percent (minimum) --f A governor system with electric hydraulic governor actuators will be provided for each of the Devil Canyon units.The system will be the same as for Watana (see Section 3.4). 851011 A-8-2 I=, I I I I ( ( i J I J i ) l , I I 9 -APPURTENANT EQUIPMENT -DEVIL CANYON -STAGE II 9.1 -Miscellaneous Mechanical Equipment (0) 9.1.1 -Powerhouse Cranes (0) Two overhead type powerhouse cranes will be provided at Devil Canyon as at Watana.The crane capacity will be approximately 200 tons. 9.1.2 -Draft Tube Gates (0) Draft tube gates will be provided to permit dewatering of the turbine water passages for inspection and maintenance of the turbines.The arrangement of the draft tube gates will be the same as for Watana,except that only two sets of gates will be provided,each set with two 21-foot wide by 10.5-foot high sections. 9.1.3 -Draft Tube Gate Crane (0) A crane will be installed in the surge chamber for installation and removal of the draft tube gates.The crane will be either a monorail (or twin monorail)or a gantry crane with an approximate capacity of 30 tons.The crane will be pendant-operated and have a two point lift.A follower will be used with the crane for handling the gates.The crane runway will be located along the upstream side of the surge chamber and will extend over the intake for the compensation flow pumps as well as a gate unloading area at one end of the surge chamber. 9.1.4 -Miscellaneous Cranes and Hoists (0) In addition to the powerhouse cranes and draft tube gate cranes, the following cranes and hoists will be provided in the power plant: o A 5-ton monorail hoist in the transformer gallery for transformer maintenance; o Small overhead,jib,or A-frame type hoists in the machine shop for handling material;and o A-frame or monorail hoists in other powerhouse areas for handling small equipment. 851011 A-9-1 ~ ! I I I I I I j l j i -1 851011 9.1.5 -Elevators (0) Access and service elevators will be provided for the power plant as follows: a Access elevator from the control building to the powerhouse; a Service elevator in the powerhouse service bay;and a Inspection hoists in ~able shafts. 9.1.6 -Power Plant Mechanical Service Systems (0) The power plant mechanical service systems for Devil Canyon will be essentially the same as discussed in Section 5.1(f)for Watana,except for the following: a There will be no main generator breakers in the power plant;therefore,circuit breaker air will not be required. The high pressure air system will be used only for governor as well as instrument air.The operating pressure will be 600 to 1,000 psig depending on the governor system operating pressure. a An air-conditioning system will be installed in the powerhouse co~trol room. a Heating and ventilating will be required for the entrance building to the access shaft ~n the south abutment. a For preliminary design purposes,only one drainage and one dewatering sump have been provided in the powerhouse.The dewatering system will also be used to dewater the intake. 9.1.7 -Surface Facilities Mechanical Service Systems (0) The entrance building above the power plant will have only a heating and ventilation system.The mechanical services in the standby power building will include a heating and ventilation system,a fuel oil system,and a fire protection system,as at Watana. 9.1.8 -Machine Shop Facilities (0) A machine shop and tool room will be located in the powerhouse service bay area to take care of maintenance work at the plant. A-9-2 \ ( J j I I I i I I r 1 l I i I ! I I l The facilities will not be as extensive as at Watana.Some of the larger components will be transported to Watana for necessary machinery work. 9.2 -Accessory Electrical Equipment (0) 9.2.1 -General (0) The accessory electrical equipment described below includes the following: o Main generator step-up 15/345 kV transformers; o Isolated phase bus connecting the generator and transformers; o 345 kV oil-filled cables from the transformer terminals to the switchyard; o Control systems;and o Station service auxiliary ac and dc systems. Other equipment and systems described include grounding,lighting system and communications. The main equipment and connections in the power plant are shown in the single line diagram (Plate F68).The arrangement of equipment in the powerhouse,transformer gallery,and cable shafts is shown in Plates F63 to F65. 9.2.2 -Transformers and HV Connections (0) Twelve single-phase transformers and one spare transformer will be located in the transformer gallery.Each bank of the three single-phase transformers will be connected to one generator by isolated phase bus located in bus tunnels.The HV terminals of the transformer will be connected to the 345 kV switchyard by 345 kV single-phase,oil-filled cables installed in 800-foot long vertical shafts.There will be two sets of three single-phase 345 kV oil-filled cables installed in each cable shaft.One additional set will be maintained as a spare three-phase cable circuit in the second cable shaft.These cable shafts will also contain the control and power cables between the powerhouse and the surface control room,as well as emergency power cables from the diesel generators at the surface to the underground facilities. 851011 A-9-3 \ I J ! I 1 j i I ( I I l ! i I ( I I 1 9.2.3 -Main Transformers (0) The transformers will be of the single-phase,two-winding, oil-immersed,forced-oil water-cooled (FOW)type.A total of twelve single-phase transformers and one spare transformer will be provided,with rating and characteristics as follows: Rated capacity: High Voltage Winding: Basic Insulation Level (BIL)of HV Winding: Low Voltage Winding: Transformer Impedance: 9.2.4 -Generator Isolated Phase Bus (0) 70 MVA 345/1.73 kV,grounded Y 1300 kV 15 kV,Delta 15 percent Isolated phase bus connections will be located between the generator and the main transformer.The bus will be of the self-cooled,welded aluminum tubular type with design and construction details generally similar to the bus at the Watana power plant.The rating of the main bus will be as follows: Rated current: Short circuit current momentary: Short circuit current symmetrical: Basic Insulation Level (BIL): 9.2.5 -345 kV Oil-Filled Cable (0) 9000 amps 240,000 amps 150,000 amps 150 kV l 851011 The cables will be rated for a continuous maximum current of 400 amps at 345 kV +5 percent.The cables will be of single-core construction with oil flowing through a central oil duct within the copper conductor.The cables will be installed in the 800-foot cable shafts from the transformer gallery to the surface.No cable jointing will be necessary for this installation length. 9.2.6 -Control Systems (0) The Devil Canyon power plant will be designed to be operated as an unattended plant.The plant will be normally controlled through supervisory control from the Susitna Area Control Center at Watana.The plant will,however,be provided with a control room with sufficient control,indication,and annunciation equipment to enable the plant to be operated during emergencies by one operator in the control room.In addition,for the purpose of testing and commissioning and maintenance of the plant,local control boards will be mounted on the powerhouse floor near each unit. A-9-4 ( I ~ I I i I I i r j l ( j I ! I I J Automatic load-frequency control of the four units at Devil Canyon will be accomplished through the central computer-aided control system located at the Watana Area Control Center. The power plant will be provided with "black start"capability similar to that provided at Watana to enable the start of one unit without any power in the powerhouse or at the switchyard, except that provided by one emergency diesel generator.After the start-up of one unit,auxiliary station service power will be established in the power plant and the switchyard;the remaining generators can then be started one after the other to bring the plant into full output within the hour. As at the Watana power plant,the control system will be designed to permit local-manual or local-automatic starting,voltage ad- justing,synchronizing,and loading of the unit from the powerhouse control room at Devil Canyon. The protective relaying system is shown in the main single line diagram (Plate F68)and is generally similar to that provided for the Watana power plant. 9.2.7 -Station Service Auxiliary AC and DC Systems (0) 851011 (a)AC Auxiliary System (0) The auxiliary system will be similar to that in the Watana power plant except that the switchyard and surface facilities power will be obtained from a 4.16 kV system supplied by two 5/7.5 MVA,OA/FA,oil-immersed transformers connected to generators Nos.1 and 4,respectively.The 4.16 kV double-ended switchgear will be located in the powerhouse.It will have a normally-open tie breaker which will prevent parallel operation of the two sections.The tie breaker will close on failure of one or the other of the incoming supplies.The 1400 hp compensation flow pumps will be supplied with power directly from the 4.16 kV system. Two 4.16 cables installed in the cable shafts will supply power to the surface facilities. The 480 V station service system will consist of a main 480 V switchgear,separate auxiliary boards for each unit, essential auxiliaries board,and a general auxiliaries board.The main 480 V switchgear will be supplied by two 2,000 kVA,15,000/480 V grounded wye sealed gas dry-type transformers.A third 2,000 kVA transformer will be maintained as a spare. Two emergency diesel generators,each rated 500 kW,will be connected to the 480 V powerhouse main switchgear and 4.16 A-9-5 I I J I I I i ( I l I J kV surface switchboard,respectively.Both diesel generators will be located at the surface. An uninterruptible high-security power supply will be provided for the supervisory computer-aided plant control systems. (b)DC Auxiliary Station Service System (0) The dc auxiliary system will be similar to that provided at the Watana plant and will consist of two 125 V dc lead-acid batteries.Each battery system will be supplied by a double-rectifier charging system.A 48 V dc battery system will be provided for supplying the supervisory and communications systems. 9.2.8 -Other Accessory Electrical Systems (0) The other accessory electrical systems including the grounding system,lighting system,and powerhouse communications system will be similar in general design and construction aspects to the system described in Section 5.2 for the Watana power plant. 9.3 -Switchyard Structures and Equipment (0) 9.3.1 -Single Line Diagram (0) A breaker-and-a-half single line arrangement will be used at the switchyard.This arrangement was selected for reliability and security of the power system.Plate F69 shows the details of the switchyard single line diagram. 9.3.2 -Switchyard Structures and Layout (0) The switchyard layout will be based on a conventional outdoor type design.The design adopted for this project will provide a two-level bus arrangement.This design is commonly known as a low station profile. The two-level bus arrangement is desirable because it is less prone to extensive damage in case of an earthquake.Due to the lower heights,it is also easier to maintain. 851011 A-9-6 ! I J I I I i ! I I i I 1 [ i I ] I [ 10 -TRANSMISSION LINES -DEVIL CANYON STAGE II (**) As part of the Stage II Devil Canyon development,the transmission system will be supplemented.Two single-circuit 345 kV transmission lines will be built between the Devil Canyon switchyard at the power development and the Gold Creek switching station. From the Devil Canyon substation the lines will head directly west for a distance of approximately one mile where they will intersect the Watana to Gold Creek transmission corridor.From this point to the Gold Creek switching station the lines will share the same corridor as the Watana lines. At Gold Creek,345 kV breakers will be added in an new bay within the switching station.The new circuit breakers will provide switching and terminations for the incoming lines and accommodate a new line to Anchorage. 851011 A-1O-1 j I ~ I I I I I -I -I I 11 -PROJECT STRUCTURES -WATANA STAGE III (***) This section describes the project features that will be altered or added during third stage construction of the Watana development.Stage III consists of increasing the plant capacity and energy generation by raising Watana Dam and the reservoir maximum normal operating level, and by adding two generating units. 11.1 -General Arrangement (***) The raising of Watana Dam during Stage III will create a reservoir approximately 48 miles long with a surface area of 38,000 acres,and a gross storage capacity of 9,500,000 acre-feet at the normal maximum operating level of el.2,185. The maximum water surface elevation during flood conditions will be 2,199.3 The minimum operating level of the reservoir will be el. 2,065,providing a live storage during normal operation of 3,700,000 acre-feet. The Stage I internal zoning will be maintained in raising the dam.The nominal crest elevation of the dam will be 2,205,with a maximum height of 885 feet above the foundation and a crest length of 4,100 feet.The embankment crest will initially be cambered to el.2,210 to allow for potential settlement.The total volume of fill material placed in the dam during this will be 26,363,000 cubic yards,bringing the total volume of the dam to 58,470,000 cubic yards. A new power intake will be constructed adjacent to the existing two intakes.The existing intake concrete superstructure will be raised to accommodate the higher reservoir level.Simultaneously,the concrete superstructure for the outlet facilities will also be raised.The approach channel constructed during Stage I will be adequate for the efficient flow of water to all intakes. Additional power capacity will be achieved by the increased head on the Stage I generating units,which were designed for this reservoir raising,and the two additional generating units installed during this stage.This installation will require an extension of the powerhouse chamber to the south of the service bay.Similar extensions will be required to the south of the transformer gallery and surge chamber. The excavated cross sections of these chambers will be the same as the Stage I chambers. A third power shaft and tunnel bifurcating into penstocks to supply water to the two generating units will be excavated and lined with concrete from the new intake structure.The power conduit will have an internal diameter of 24 feet. 851011 A-ll-l I 1 j I I ! I l I I I I I I J l / The penstocks will be steel-lined for a distance of 200 feet upstream of the powerhouse.The steel-lined section will have a diameter of 15 feet.The remaining penstock reach to the bifurcation will be 18 feet in diameter. The normal reservoir fluctuation for power generation will be 120 feet, from the normal maximum pool at el.2,185 to the minimum normal pool at el.2,065. The surge chamber extension will be hydraulically joined to the powerhouse cavern by two draft tube tunnels.The turbine discharges will flow from the south end of the surge chamber by a second 34 foot diameter concrete-lined modified horseshoe tunnel.This tunnel will intersect the Number 2 diversion tunnel,which will be used to complete the tunnel tailrace system,and discharge to the river downstream of the dam.The transformer gallery extension will house a bank of three additional single-phase 15-345/1.73 kV transformers serving the two generators.The transformers will be connected by three 345 kV single-phase gas insulated SF6 busses,and led through an existing shaft to the transmission yard at the surface. There will be no change to the outlet facilities downstream of the intake structure. The maximum outlet works discharge required to pass the 50-year flood at Watana without operating the spillway is approximately 24,000 cfs. In combination with a powerhouse flow of 7,000 cfs this will cause the Watana water level to be raised to el.2,193.The average powerhouse flow during the passing of the 50-year flood may reach 9,900 cfs.This may result in Watana outflows of 33,900 cfs.The resulting inflow to Devil Canyon may reach approximately 43,000 cfs.The Devil Canyon outlet works has the capacity to pass 42,000 cfs without operating the spillway.A 1.0 foot surcharge has been provided at the Devil Canyon Dam to store flow in excess of the outlet works capacity.Therefore the raising of the reservoir will increase the discharge capacity of the outlet works for the maximum valve settings (80%gate stroke)from 24,000 cfs to 30,000 cfs.However,this extra capacity is not needed in Stage III to store and release the 50-year flood without operating the spillways.The project operating policy during floods is to transfer as much energy generation from the Devil Canyon powerhouse to the Watana powerhouse as necessary to pass the flood without raising the water level above el.2,193 or opening the spillway.The Devil Canyon outlet works has the capacity to pass the outflow from Watana plus intervening flow without raising the Devil Canyon water level above el.1,456.0 or requiring use of that spillway.Gas concentrations downstream of the dams are expected to be below naturally occurring levels. The spillway control structure will require a substantial modification. The bridge will be removed,and the piers and abutment wall concrete 851011 A-11-2 I 1 J 1 I I 1 I j I j l I I , j I I J L~I will be raised.This will be followed by raising the ogee section to a crest elevation of 2,135.The Stage I radial gates and hydraulic hoists will be re-installed.The ogee section will,in effect,be a gravity dam section with its downstream face forming the upper reach of the spillway chute prior to joining the lower reach which was constructed during Stage I.The spillway will still have the capacity to pass the Probable Maximum Flood (PMF)wi thout overtopping the dam. The emergency release facilities constructed in diversion tunnel No.1 will still be available for lowering of the reservoir over a period of time to permit emergency inspection or repair to the impoundment structures. 11.2 -Dam Embankment (***) The Stage I Watana Dam has been designed with the intent of raising it during Watana Stage III development.In general,the outer slopes and internal zoning of the Stage I dam will be raised to the nominal final Stage III crest level of el.2,205.Some excavation at the top of the Stage I dam will be necessary to ensure continuity of the zones between Stages I and III construe tion.The dam will be"compacted earth and rockfill construction and will consist of an impervious core protected by fine and coarse filters upstream and downstream.The upstream and downstream outer shells will consist of rockfill.A typical cross section is shown on Plate F77 and is described below. 11.2.1 -Typical Cross Section (***) The basic cross section of the Stage III dam is the same as the Stage I dam.Filter and impervious core thickness criteria are the same as for Stage I;core and filter thicknesses in the Stage I development take into account for the higher reservoir levels which will be present after Stage III. The upstream and downstream filter zones provide protection against possible piping through transverse cracks that could occur because of settlement or resulting from internal displacement during a seismic event.The shells of the dam will consist of rockfill obtained from Quarry Site A.The rockfill will minimize pore pressure generation and ensure rapid dissipation of pore pressures should seismic shaking occur. As in Stage I,protection against wave and ice action on the upstream slope will consist of a quarried-rock raked layer of large stone up to 36 inches in size. The volume of material required to construct the Stage III Watana Dam is presently estimated as follows: o Impervious material: o Fine filter material: 1,552,000 cubic yards 753,000 cubic yards 851011 A-11-3 I I J I I I I I I I I J l I I I I I I 11.2.2 -Crest Details and Freeboard (***)J o o Coarse filter material: Rockfill material: 679,000 cubic yards 22,936,000 cubic yards -I l 851011 The typical crest detail is shown in Plate ~77.Because of the narrowing at the dam crest,the filter zones are reduced in width but still protect the core material from damage by frost penetration and desiccation. The nominal crest elevation of Watana Stage III will be 2,205. The total settlement allowance considered results in a deforma- tion of up to 0.5 percent of the height of the dam.During construction of the dam,additional allowances will be made for post-construction settlement of the dam under its own weight,for the effects of saturation on the upstream rock fill when the reservoir is first filled,and for possible settlement from seismic shaking.Provision will be made during construction for placement of additional fill at the crest should settlements exceed the estimated amounts.At each abutment the crest el.will be 2,205 while the central portion of the embankment would be to el.2,210.Under normal operating conditions the minimum freeboard relative to the maximum operating pool elevation of 2,185 will be approximately 20 feet. The PMF freeboard allowance of six feet is based on the crest level after all settlement has taken place.Less PMF level freeboard is necessary at Stage III than at Stage I because of the greater storage capabilities of the reservoir basin. Ultimate security against overtopping of the dam will be provided by the spillway which is designed to pass the PMF without overtopping the dam. 11.2.3 -Grouting and Pressure Relief System (***) The majority of the grouting and pressure relief system will have been constructed during Stage I.However,consolidation grouting along the abutments above el.2,025 will be required in the core foundation during Stage III.In addition,grouting and drainage galleries,the grout curtain,and pressure relief drain holes,will be constructed above the existing Stage I to the final Stage III level. The grout curtain and drilling for the pressure relief system will be largely carried out from galleries in the rock foundation in the abutments and beneath the dam.Details of the grouting, pressure relief,and galleries are shown on plate F78. A-ll-4 ) I J I 1 I I ) I ) ) ] 1 I I l 11.2.4 -Instrumentation (***) Instrumentation will have been installed during Stage I to provide monitoring of performance of the dam and foundation during construction as well as during operation.Instruments for measuring internal vertical and horizontal displacement,stresses and strains,and total fluid pressures,as well as surface monuments and markers,were installed.This instrumentation will also provide monitoring capabilities during and after Stage III construction.Some additional instrumentation will be required in the Stage III zone between elevations 2,025 and 2,205. Conservative quantity estimates for instrumentation have been made on the basis of currently available geotechnical data for the site. (a)Piezometers (***) o Piezometers will be used to measure static fluid pressure in the pore space of soil,rockfill,and 1n the rock foundation. (b)Internal Vertical Movement Devices (***) o Cross-arm settlement devices as developed by the USBR o Various versions of the taunt-wire devices which have been developed to measure internal settlement o Hydraulic-settlement devices of various kinds (c)Internal Horizontal Movement Devices (***) o Taunt-wire arrangements o Cross-arm devices o Inclinometers o Strain meters (d)Other Measuring Devices (***) o Stress meters o Surface monuments and alignment markers o Seismographic records and seismoscopes o Flow meters to record discharge from drainage and pressure relief system 11.3 -Diversion (***) Passage of river flows during Stage III will be accomplished by in-place Stage I project features.Stage III diversion will involve reconstructing the downstream cofferdam over the in-place slurry trench cutoff,and dewatering the area between the Stage I dam and the cofferdam by pumping.Construction will involve approximately 10,000 851011 A-1l-5 i I J I I I I ) i ) I l -J) i I ) I I cubic yards of impervious fill,and 16,000 cubic yards of rockfill and filter material.The foundation cutoff of this cofferdam will be sufficiently water tight that once the area downstream of the dam is dewatered,minimum pumping to tailwater will be required to maintain adequate drainage so that Stage III Watana foundation preparation and fill placement can occur.This care and handling of water will be required for one construction season. 11.4 -Emergency Release Facilities (***) The emergency release facilities constructed during Stage I will not be subjected to any change during Stage III.The description of these facilities is presented in 1.4 -Emergency Release Facilities.The gated concrete plugs,and the bonnetted-type high pressure slide gates installed therein will have been designed for the hydraulic head imposed by the Stage III reservoir level.The emergency release facilities will not be operated under head conditions exceeding 600 feet.The upstream and downstream gates will be operated in unison maintaining equal gate openings in order to balance the hydraulic head drop across the gates.Energy dissipation at the diversion tunnel exit will be accomplished by the concrete flip bucket in the exit channel. 11.5 -Outlet Facilities (***) The primary function of the outlet facilities remains the same as in Stage I,which is to discharge floods with recurrence frequencies of up to once in 50 years with minimum downstream erosion and minimum generation of dissolved nitrogen in the discharges.As before,the secondary function is the capability of drawing the reservoir down during an extreme emergency situation. The descriptions (for the approach channel only)found in 1.5.1, Approach Channel and Intake,1.5.2,Intake Gates and Trashracks,1.5.3, shaft and Tunnel,1.5.4,Discharge Structure,1.5.5,Fixed Cone Valves, 1.5.6,Ring Follower Gates,and 1.5.7,Discharge Area,are still valid for the Stage III development.All structures and equipment constructed and installed in Stage I are designed for Stage III loadings. The Stage III development of the outlet facilities will be limited to the raising of the intake superstructure.This work will entail raising the concrete exterior walls,central pier and placing a new deck at el.2,207.The stop log and trashrack guides will be extended so that the stop logs and trash racks may be placed and removed from the new deck level.Access to the intake structure will be via an embankment which joins the crest of the dam.The Stage III Intake is shown on Plate F80. 851011 A-1l-6 I ~ ,\ 1 ) I ) I I I l -) i 1 I ,I I l l 11.6 -Spillway (***) The function of the Stage III spillway is still to provide discharge capability for floods exceeding the capacity of the outlet facilities (50-year flood).The spillway and outlet facility will have a combined capacity to pass flood inflows to the reservoir with a frequency of occurrence of up to and including the Probable Maximum Flood (PMF). Plate F79 shows the Stage III spillway,and indicates that the modification to the Stage I spillway is restricted to the control structure.The control structure will take on the appearance of a gravity dam spillway by raising the Stage I control structure between the approach channel and the chute channel.The overflow and chute sections will be hydraulically model tested to determine its configuration during the Stage I detailed design phase. 11.6.1 -Approach Channel and Control Structure (***) The approach channel,as excavated in Stage I,will requ1re no change for the Stage III development.The concrete control structure overflow section will be raised in phases once the crest of the dam has reached el.2,050. (a)Phase I (***) At this point,concrete stop logs will be placed upstream of the control structure at a spillway end bay,bearing on the pier nose,and in a slot in the abutment wall.The water will be evacuated from the area between the stop logs and the radial gate prior to the removal of the gate for reuse when the concrete in the bay is at its final level. The remaining two bays,with increased reservoir surcharges, will provide suffic1cent capacity to pass extreme flood events.Concrete will be placed in the initial bay to el. 2,014. (b)Phase II (***) A second bay will be closed when the dam crest is no less than el.2,080 and the process indicated in (a)will be repeated.Concrete placement in the second bay will terminate upon reaching el.2,014. (c)Phase 111(***) The third and last bay will be closed when the dam crest elevation is no less than el.2,100 and the initial process indicated in (a)will be repeated.Extreme flood events will be passed over the stop logs of the bay under 851011 A-11-7 -"I \ J ,l \ I I I i 1 ) 1 -I I I ) ] ,I i (d) construction and incomplete crest at el.2,014.Once concrete placement in the third bay reaches el.2,014, concrete placement will begin in the other two bays. Phase IV (***) During the final phase of concreting,placement will be in all bays allowing a more or less uniform raising of the concrete structure.The radial gates and bridge structure will be places once again in position on the raised struc ture. 11.6.2 -Spillway Gates and Stop Logs (***) This equipment and arrangement is the same as that of Stage I which is described in 1.6.2. 11.6.3 -Spillway Chute (***) The Stage III control structure will trans~t~on to the inclined Stage I chute which is described in 1.6.3. 11.6.4 -Flip Bucket (***) There are no changes to the Stage I flip bucket described ~n 1.6.4. 11.6.5 -Access (***) The deep cuts in rock required for access in Stage I will be filled with impervious material on the abutment side of the spillway and topped out with a roadway surface which follows the Stage I horizontal access road alignment.The south spillway abutment will be joined by the Stage III dam embankment. 11.7 -Power Intake (***) 11.7.1 -Intake Structures (***) The Stage I intake structures Nos.1 and 2 serving generating Units 1 to 4 will be raised and an intake structure adjacent to Intake No.2 will be constructed (see Plate F83).The foundation for the new intake structure is at el.2,002.Both the new intake and the Stage I intakes will be raised simultaneously while maintaining the Stage I generating requirements.The new intake will be provided with four pairs of openings in its upstream wall,all of which can be closed-off with sliding steel shutters.In the Stage I intakes,which are being raised,the 851011 A-1l-8 I I ) j l --' I I I I 1 I I I 'l -I I i ) I J -! pattern and spacing of pairs of openings will be the same as in the new intake.All openings will be protected by trashracks upstream of the shutter openings.A heated boom will operate in guides upstream from the racks following the water surface, keeping the racks ice free. The reservoir fluctuation in Stage III will be 120 feet from the reservoir el.2,185.The upper level of the intake structures will be el.2,201.Mechanical equipment will be housed at this level in a steel frame building.Part will have been removed from the Stage I deck.and the remainder will be a new extension for Intake No.3. 11.7.2 -Approach Channel (***) There are no changes to the Stage I approach channel described in 1.8.2.Due to the substantially increased depth of flow in the approach channel,the velocities of flow during normal and extreme conditions will be less than that of Stage I for the same conditions. 11.7.3 ~Mechanical Arrangement (***) (a)Ice Boom (***) A heated boom will be installed in the guides immediately upstream of the trashracks of intake No.3.The heated booms of intakes No.1 and 2 will rise in the structures guides as the reservoir is filled minimizing ice accumulation on the trashrack and intake shutters. (b)Trashracks (***) The intake structure No.3 will have four sets of trashracks,each set will consist of a pair of trashracks divided in two sections to facilitate handling by the intake service crane.Each set of trashracks will cover two openings 24 feet wide by 25 feet high.The trashracks will have a bar spacing of 6 inches and will be designed for a maximum differential head of 20 feet. For Intake Structures No.1 and 2 the trashracks will be transferred from the lower level to the upper four openings of the Stage III addition.These trashracks will be designed in accordance with the criteria indicated above. (c)Intake Shutters (***) Three sets of intake shutters will be installed in each of the new intake No.3 and the raised intakes Nos.1 and 2 851011 A-11-9 ,( I J I I I I I I I I I l -1 I I I I I l J 851011 (d) (e) (f) to prevent flow through the openings behind which the shutter will be installed.As the reservoir level changes, the sliding shutters will be removed or replaced as necessary using the intake service crane. Each of the shutters will be designed for a differential head of 15 feet,and will incorporate a flap gate.This will prevent failure of the shutters in the event of an accidental blockage of all intake openings. The shutter guides will be heated to facilitate removal in sub-freezing weather.In addition,a bubbler system will be provided in the intake behind the shutters to keep the intake structure water surface free of ice. Intake Service Crane (***) The overhead traveling-bridge type intake service crane used in Stage I will be transferred to the Stage III deck where the crane runway will be extended to cover Intake No.3. The crane will be used for: o Servicing the ice boom and ice boom hoist, o Handling and cleaning the trashracks, o Handling the intake shutters, o Handling the intake bulkhead gates,and o Servicing the intake gate and hoist. The overhead crane will have a double point lift and followers for handling the trashrack shutters and bulkhead gates.The crane will be radio-controlled with a pendant or cab control for backup. Intake Bulkhead Gates (***) The set of bulkhead gates provided to close the Stage I intakes will also be used for the Stage III Intake No.3. The bulkhead gates will be used to permit inspection and maintenance of the intake gate and intake gate guides.The gates will be designed to withstand maximum differential pressure that will occur in No.1 and 2 intakes. Intake Gates (***) Intake gates will be provided to close the two No.3 intake openings which are 12 feet wide by 24 feet high.The gates and operation thereof will be similar to the Stage I intake gates described in 1.8.3(f),although by virtue of the intakes vertical location the design head will be substantially reduced. A-II-I0 1 I J I I I i I I i l --I I I J I I ~I 11.8 -Power Tunnel and Penstocks (***) The general arrangement of the Stage III power tunnel and penstocks is shown on Plate F76.There are no changes to the Stage I arrangement. A single power tunnel from Intake No.3 which bifurcates to penstocks is provided to convey water to each of the two new generating units. The power tunnel and penstocks will have a minimum concrete lining thickness of 18 inches and the penstock will be steel lined in the 200 foot reach immediately upstream of the powerhouse cavern. 11.8.1 -Steel Liner (***) The description of criteria and parameters presented in 1.9.1 is also valid for Stage III. 11.8.2 -Concrete Lining (***) The description presented in 1.9.2 1S also valid for Stage III. 11.8.3 -Grouting and Pressure Relief System (***) The comprehensive pressure relief system,established in Stage I, to protect the underground caverns against seepage from the high pressure penstock will be continued to provide protection for the extended caverns.This system comprised small diameter bore holes set out to intercept the jointing in the rock.A grouting and drainage gallery previously constructed in Stage I will provide the origin for this system. 11.9 -Powerhouse (***) The existing Stage I powerhouse complex beneath the north abutment of the dam will be extended in Stage III towards the river to accommodate two additional generating units.This will require rock excavation in three caverns -the powerhouse,transformer gallery,and surge chamber -and interconnecting tunnels for the draft tubes, isolated phase bus ducts and tailrace. The general layout of the powerhouse complex is shown 1n Plates F86 to F89. 11.9.1 -Access Tunnels and Shafts (***) Except for a cross adit to be excavated from diversion tunnel No.2 to the adjacent penstock construction adit,no additional access tunnels or shafts will need to be excavated in Stage III. 851011 A-ll-ll I I J I I I I I ! j I I 1 -! I ! ] j ~1 I 851011 11.9.2 -Powerhouse Cavern (***) The main powerhouse cavern extension will accommodate two additional vertical-shaft Francis turbines,with direct coupling to synchronous generators.Each unit will have a maximum output capability of 200 MW.The maximum output capabilities of the four Stage I turbines will also be increased to 200 MW due to the increased reservoir head. The cavern extension will allow for the 60-foot long unit 5 and 6 monolith,and a 40-foot long laydown bay at the south end. The two additional units will be separated form the existing units by a 69-foot long rock pillar,through which a drainage tunnel will have been excavated during Stage I construction. Multiple stairway access points will be available from the main generator floor to each gallery level.Additional access to the transformer gallery will be provided by stairway through a third isolated phase bus tunnel. 11.9.3 -Transformer Gallery (***) The unit 5 and 6 transformers will be located underground in an extension of the transformer gallery,which is located 120 feet upstream from the powerhouse cavern.A third connecting tunnel will be added for the isolated phase bus.There will be three single-phase transformers rated at 15-345/1.73 kV,150 MVA for the two generating units.Generator circuit breakers will be installed in the powerhouse on the generator floor level.The transformer gallery extension will be 45 feet wide,20 feet high and 106 feet long;the bus tunnel will be 16 feet wide and 16 feet high. A third station service auxiliary transformer (2 MVA)will be located in the isolated-phase bus tunnel. Vehicle access to the transformers gallery will be by the existing main powerhouse access tunnel at the south end. Pedestrian access will be from the existing main access shaft or through each of the three isolated phase bus tunnels. 11.9.4 -Surge Chamber (***) The surge chamber located 120 feet downstream form the powerhouse cavern,will be extended by the length of the powerhouse service bay,and by the two additional unit bays,for a total extension of 215 feet.The runway for the existing crane will be extended to allow access for placement of the stoplogs for a second trailrace tunnel. A-ll-12 ( I J I I I I r ( I I i l -! I I I ! ( J l J l -I 11.9.5 -Grouting and Pressure Relief System (***) Additional drain and grout holes will be drilled from the previously constructed adit,and from the cavern extension. 11.9.6 -SF6 Gas Insulated Bus Shaft (***) No additional SF6 GIS will be required. 11.9.7 -Draft Tube Tunnels (***) A 19-foot diameter tunnel will be constructed for each of the two additional generating units. 11.10 -Trailrace (***) A second tailrace pressure tunnel will be provided to carry water from the surge chamber to the river.This second tunnel will also be a .modified horseshoe cross section with a major internal dimension of 34 feet.It will connect the southern end of the surge chamber extension to the existing Division Tunnel No.2,and will incorporate the cross adits between the penstock construction adit and the diversion tunnel which has to be provided for Stage III penstock construction.It will connect the surge chamber extension to the existing Diversion Tunnel No.2. 11.11 -Access Plan (***) Project access during Stage III will be the same as developed and used for Stage I.The primary objective of access is to provide a transportation system that will support construction activities and allow for the orderly development and maintenance of site facilities. The access plan is discussed in Section 1.12. 11.12 -Site Facilities (***) Stage I site facilities will be used during Stage III,and are as described in Section 1.13. 11.13 -Relict Channel (***) A relict channel exists on the north bank of the reservoir approximately 2,600 feet upstream from the dam.This channel runs from the Susitna River gorge to Tsusena Creek,a distance of about 1.5 miles.The surface elevation of the lowest saddle is approximately 2,205,and depths of up to 454 feet of glacial deposits have been identified. To ensure the integrity of the rim of the Watana Reservoir and to control losses due to potential seepage,a number of conditions have 851011 A-Il-13 ( ! J ! I I I i I i I i 1 -! I i l J 9 l been evaluated.Study types include settlement of the reservoir rim, subsurface flows,permafrost and liquefaction during earthquakes. 11.13.1 -Surface Flows (***) Based on information gained from past exploration programs,the relict channel soils are either dense or cohesive and as such are not deemed to be subject to settlement resulting for seismic shaking.Therefore,the low ground surface in the area will more than provide adequate freeboard as it is several feet above the Stage III dam crest which is at el.2,205. 11.13.2 -Subsurface Flows (***) The potential for progressive piping and erosion in the area of discharge into the Tsusena Creek will be controlled by continuous monitoring of the outlet area,undertaken for a lengthy period after Stage I reservoir filling,to ensure that a state of equi librium has been established with respec t to permafrost and seepage gradients in the buried channel area. If seepage through the alluvium is found to be excessive during or following Stage I impoundment,or becomes excessive following Stage III impoundment,a IIwors t case ll provision has been made to construct a slurry trench cutoff through the upstream alluvium at the narrow throat of the relict channel.A sufficient allowance has been made in the Watana construction cost for such cutoff construction and additional seepage pressure reduction measures. 11.13.3 -Permafrost (***) The permafrost discussion in Section 1.14.3 for Stage I 1S applicable to Watana Stage III. 11.13.4 -Liquefaction (***) Liquefaction was discussed in Section 1.14.4 for Stage I.No additional geotechnical investigations of the relict channel are foreseen during Stage III. 11.13.5 -Remedial Work Influence on Construction Schedules (***) Relict channel remedial treatment construction work,if necessary,will have pratically no impact on the Watana Dam Stage III construction schedule.Because the relict channel work will be located near Borrow Site D,some coordination will be required between these two operations.Once this coordination has been accomplished,dam construction and the relict channel work can be concurrently accomplished. 851011 A-1l-14 I I J j I I I i i I j I l -1 ! i j I I ~1 I 851011 11.13.6 -Relict Channel Treatment Summary (***) Early concerns regarding the critical impact of the relict channel on the Watana project appear to be unfounded. Nevertheless,some uncertainties still exist and,therefore, costs ($57.1 million)for responding to the unknown concerns have been included in the Watana cost estimates for Stages I and III. During design investigations,additional boreholes and inspection trenches will be employed to further delineate the relict channel foundation.The area will be studied during Borrow Site D excavation.The area will also be thoroughly monitored by observation devices during Stage I reservoir filling and operation,and Stage III reservoir filling to assess actual hydrological conditions in the relict channel. Based on existing knowledge,the only remedial measures that may possibly be needed for the relict channel involve seepage control.To satisfy project feasibility until future exploration indicate that no seepage problems exist within the buried channels ("K"unit),costs ($51.0 million)have been included in Stage III for a positive seepage cutoff similar to an I.C.O.S.wall. The slurry trench would be in combination with a downstream toe drain.Should future design studies and investigations so indicate,a less conservative design will be considered. A-II-IS I 4 I l ( I i ! I I J j 12 -Reservoir Data -Watana Stage III (***) The Watana Reservoir,at a normal operating level at el.2,185 feet, will be approximately 48 miles long with a maximum width in the order of 5 miles.The total water surface area at normal operating level is 38,000 acres.The minimum reservoir level will be at el.2,065 feet during normal operation,resulting in a maximum drawdown of 120 feet. The reservoir will have a total capacity of 9.5 million acre-feet,of which 3.7 million acre-feet will be live storage. 851011 A-12-1 ( I ~ I I i I l ! i i j I I l J -I 13 -Turbines and Generators -Watana -Stage III (***) 13.1 -Unit Capacity (***) The Watana powerhouse will have six generating units:the four from Stage I and two additional units installed in Stage III.The maximum generator output of all six units will be 200 MW corresponding to the maximum normal reservoir level (el.2,185),and a corresponding head of 719 feet.The net head on the plant will very from 600 feet to 719 feet.the turbine design net head of the two new units has been established at 680 feet. The generator rating is the same as for the Stage I units (Section 3.1).Unit characteristics including generator outputs are described in Table F.!. 13.2 -Turbines (***) The two additional turbines for Stage III will be of the vertical shaft Francis type,with steel spiral casing and a steel lined concrete elbow-type draft tube.The draft tube will comprise a single water passage without a center pier.These two turbines will be identical. These two turbines will also be identical to the Stage I turbines except for the design head selection.The design head is the head selected for optimum efficiency of operation.The narrower range of operating heads in Stage III will permit selection of a design head at the ultimate average operating head. The rated output of each turbine will be approximately 174 MW at 645 feet rated net head.Maximum and minimum net operating heads on the units will be 719 feet and 600 feet,respectively.The full gate output of each turbine will be about 204 MW at 719 feet net head and 155 MW at 600 feet net head.Each turbine will be provided with a l2.5-foot diameter,straight flow-type butterfly valve.These guard valves will be located within the powerhouse just upstream of the turbines. 13.3 -Generators (***) The generators for Stage III will be identical to the generators for Stage I.Type,rating,and excitation equipment are described in Section 3.3 -Generators. 13.4 -Governor System (***) The governing systems for Stage III will be identical to the governing system for Stage I,as described in Seciton 3.4 -Governor System. 851011 A-13-1 ( ! ~ I I I I I j I J l ! I I J j ( j l I~I 14 -Appurtenant Mechanical and Electrical Equipment -Watana Stage III (***) 14.1 -Miscellaneous Mechanical Equipment (***) The mechanical service systems required for Stage III will be essentially the same as those installed under Stage I,described in Section 4.1.6 -Power Plant Mechanical Service Systems.On a unit basis,water will be provided for generator air coolers,turbine and generator bearing coolers transformers,and turbine shaft seals.The capacities of powerhouse systems common to all units will be increased as required,with piping and duct work extended to provide service to the new units. 14.2 -Accessory Electrical Equipment (***) The accessory electrical equipment required for Stage III will be identical to those supplied for Stage I,described in Section 4.2 - Accessory Electrical Equipment. 851011 A-14-1 J j I I I i ! l j i I ,I j I J j 15 -TRANSMISSION FACILITIES -WATANA STAGE III (***) The raising of the Watana Dam during Stage III and,consequently, the upgrading of Watana generation,will require a third transmission line from the Gold Creek Switchyard to the Willow Substation and from Willow to the Knik Arm Substation. The additional Stage III transmission line will use the existing corridor (refer to Plate F98,Exhibit F). 15.1 -Transmission Requirements (***) Between Gold Creek and Knik Arm switching stations,a third 345 kV single-circuit line will be built parallel to the two Watana lines.The crossing of Knik Arm will be by cable with a similar arrangement to the original two circuits.At Willow switching station,four 345 kV breakers will be added,one in an existing bay,the rest in a new bay.These handle the new line and allow the installation of a third 75 MVA transformer for local supply, if required.Similarly,at Knik Arm switching station,a breaker will be installed in an existing bay to receive the incoming Watana line.Between the Knik Arm and University stations,the lines built for Watana were sized to accommodate the Devil Canyon need in order to limit right-of-way requirements.At University an additional transformer bank at each of 230 kV and 115 kV levels will be provided; this will involve the addition of two breakers in existing bays.At the Ester substation in Fairbanks,an additional 150 MVA transformer bank will be installed to serve the local load;this will require one new breaker in an existing bay. 15.2 -switching and Substations (***) The following substation additions will be required as part of Watana Stage III: 15.2.1 -Watana Switchyard (***) The additional generating units at Watana require a determination in the switchyard.Circuit breakers will be added to provide this termination.The additional breakers will convert the ring bus arrangement,installed during Stage I construction,into a breaker-and-a-half substation. 15.2.2 -Gold Creek Switchyard (***) Termination of the Stage III transmission line will be required.This termination will be achieved with the addition of necessary circuit breakers,and associated facilities. 851011 A-15-l I I ,! j j I I I j .1 I I ~1 I J l 15.2.3 -Ester Substation (***) An additional 150 MVA transformer bank will be installed. The transformer will step-down voltage to 138 kV,and will include a circuit breaker for termination of the transformer.The added transformer will provide additional power at 138 kV for distribution by Golden Valley Electric Association.The transformer bank will have 13.8 kV tertiary windings for connection of static var compensation (SVC)equipment.The SVC equipment will allow control of 138 kV bus voltage. The circuit breakers for connection of the SVC equipment and for the connection to local transmission lines are also included. 15.2.4 -Willow Substation (***) Terminations at this substation are for the additional Stage III transmission lines from Gold Creek and Knik Arm, and for an additional 345/138 kV 75 MVA three-phase transformer.This transformer will provide power at 138 kV for local transmission and distribution.The circuit breaker arrangement is based on a breaker-and-a-half arrangement. 15.2.5 -Knik Arm Substation (***) The termination of the third transmission line from Willow will require installation of additional circuit breaker, disconnect switches,and shunt reactor.Addition of the transmission line termination will make the whole substation arrangement a breaker-and-a-half. 15.2.6 -University Substation (***) The Stage III development will require the addition of two 250 MVA single-phase transformer banks.The circuit breakers for termination of the transformers will be added to the existing substation,and form a complete breaker-and-a-half arrangement.One transformer bank will step-down the voltage to 230 kV and the other to 115 kV. The power factor from the 230 kV line will be for di stribut ion by CEA,and from the 115 kV bus by AMPL. Both transformer banks will have 13.8 kV tertiary windings for SVC equipment connections.Circuit breakers for SVC equipment connections and local transmission lines are included. 851011 A-15-2 J I I I I I I j I I l J ) I I I I J ~ I 16 -LANDS OF THE UNITED STATES (**) The Susitna Hydroelectric Project will include numerous parcels of federal land within the project boundary as defined in Exhibit G of this application.Ownership was verified using the Bureau of Land Management (BLM)Alaska Automated Land Record System which has an approximate accuracy of 70 percent.Ownership was further verified from BLM individual case files bringing the accuracy to 95 to 98 percent.The following is a tabulation of those lands with ownership and acreage.Included in the list of federal lands are both those lands which have been selected,but not yet conveyed to non-federal owners and those lands which have been selected by and conveyed to non-federal owners. 851011 A-16-l I I ~ ) J j I, I I I ) j l I I I J ) I \ (3)Selected by Ninilchik Native Association,Inc;Salamatoff Native Association,Inc.;Seldovia Native Association,Inc.; Tyonek Native Corporation;Knikatnu,Inc.;Alexander Creek, Inc.;and Chickaloon-Moose Creek Native Association,Inc. (4)Selected by State of Alaska ~/Lands selected by Cook Inlet Region Inc.are subjected to being conveyed at any time. 851011 A-16-2 ~ J J \ ,! ) I II ) ) l I ) I J I I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) =1 U.S.ACREAGE SELECTED AND ( TOWNSHIP/Section OWNER PLATE U.S.ACREAGE ALREADY CONVEYED* T32N,R1E Section 31 CIRI G6 0 264.4 Section 32 Knikatnu G6 0 370.0 Section 33 CIRI G6&G7 0 251.8 Section 34 BLM (1)G7 22.9 0 T31N,R2E Section 1 Tyonek G8 0 189.3 Section 4 BLM (1)G7&G8 137.4 0 Section 5 CIRI G7 0 200.2 Section 6 eIRI G7 0 275.0 Section 7 BLM (1)G7 57.9 0 Section 8 BLM (1)G7 00.7 0 Section 12 Tyonek G8 0 197.1 Section 13 eIRI G8&G9 0 207.5 Section 24 BLM (1)G9 07.4 0 T32N,R2E Section 22 BLM (1)G8 00.2 0 Section 27 BLM (1)G8 51.2 0 Section 31 BLM (3)G7 01.1 0 Section 32 Knikatnu G7 0 48.0 Section 33 Knikatnu G7&G8 0 222.3 Section 34 Tyonek G8 0 176.6 Section 35 Tyonek G8 0 161.8 =-1 Section 36 Tyonek G8 0 120.9 )T31N,R3E Section 13 BLM (1)G10 43.4 0 Section 14 BLM (1)G10 97.8 0 Section 15 BLM (1)G10 108.8 0 Section 16 BLM (1)G10 17.2 0 Section 17 BLM (1)G9&G10 59.9 0 Section 18 eIRl G9 0 148.0 Section 19 eIRI G9 0 157.9 Section 20 eIRI G9&G10 0 149.3 Section 21 CIRI G10 0 226.2 851011 A-16-3 I ~ II J J \ l I ! ! )' I l I I I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) -I U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE ALREADY CONVEYED* (T31N,R3E (Cont.) Section 22 Knikatnu GI0 0 148.0 Section 23 CIRl GI0 0 201.0 Section 24 Tyonek GI0 0 323.4 T31N,R4E Section 2 CIRI G12 0 51.7 Section 3 CIRI Gll&GI2 0 268.6 Section 9 BLM (1)Gll 38.3 0 Section 10 CIRI Gll 0 0 -I Section 15 CIRI Gll 0 300.0 Section 16 CIRl Gll 0 95.6 I Section 18 BLM (1)GI0 00.2 0 Section 19 CIRl (3)GI0 0 374.4 I Section 20 CIRI GI0&Gll 0 445.7 Section 21 CIRI Gll 0 391.5 Section 29 BLM (1)GI0&Gll 02.7 0 ~T32N,R4E ) Section 25 CIRI G12 0 32.6 Section 26 BLM (3)G12 225.0 0 Section 34 BLM (1)G12 130.0 0 Section 35 Tyonek G12 0 388.0 Section 36 Tyonek G12 0 262.9 T31N,R5E ~!Section 3 BLM (1)G13&GI5 420.0 0 Section 4 BLM (1)G13 480.0 0 Section 5 BLM (1)G13 360.0 0 T32N,R5E Section 13 BLM (3)G16 60.0 0 Section 14 BLM (3)G16 260.0 0 Section 15 BLM (3)G14&G16 400.0 0 Section 16 BLM (3)G14 330.0 0 Section 17 BLM (3)G14 30.0 0 Section 19 BLM (3)G13&GI4 160.0 0 Section 20 BLM (3)G13&G14 560.0 0 Section 21 BLM (3)G13&G14 640.0 0 851011 A-16-4 j 1 ! I I j I II l i I \ )' I I I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) ~U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE ALREADY CONVEYED* (T32N,R5E (Cont.) ) Section 22 BLM (3)G13,14,15 640.0 0 Section 23 BLM (3)G15&G16 631.1 0 Section 24 BLM (3)GI0&Gll 75.2 0 Section 25 BLM (1)GIS 560.3 0 I Section 26 Knikatnu GIS 0 372.2 Section 27 Knikatnu G13&GI5 0 238.3 Section 28 CIRI G13 0 47.3 Section 29 BLM (3)G13 640.0 0 Section 30 Tyonek G13 0 38.1 Section 31 Tyonek G13 0 127.7 -I Section 32 Tyonek G13 0 196.5 Section 33 Tyonek G13 0 204.3 Section 34 BLM (1)G13&GI5 598.4 0 Section 35 BLM (1)GIS 303.5 0 I I Section 36 BLM (1)GIS 329.3 0 T31N,R6E I Section 1 (1)G17 233.8 0IBLM Section 2 BLM (1)GI7 01.9 0 I T32N,R6E Section 2 BLM (3)G18 09.3 0 1 Section 3 BLM (3)G18 01.0 0 Section 10 BLM (3)G18 201.0 0 Section 11 BLM (3)GI8 70.6 0 ~I Section 13 BLM (3)G18 482.3 0 Section 14 BLM (3)G18 243.2 0 Section 15 BLM (3)G18 507.2 0 I 1 Section 16 BLM (3)G18 00.7 0 Section 21 BLM (3)GI5,16,18 162.5 0 Section 22 BLM (3)G17&G18 640.0 0 Section 23 BLM (3)G17&G18 640.0 0 Section 24 BLM (3)G17&G18 640.0 0 Section 25 BLM (1)G17 640.0 0 Section 26 BLM (1)G17 640.0 0 Section 27 BLM (1)G17 640.0 0 Section 28 BLM (1)G15&G17 630.2 0 Section 29 BLM (1)GIS 496.0 0 Section 30 BLM (3)GIS 382.2 0 Section 31 BLM (1)GIS 333.6 0 851011 A-16-5 i ]' J j ) j \ I I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) ~U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE ALREADY CONVEYED* I~J T32N,R6E (Cont.) Section 32 BLM (1)G15 256.1 0 Section 33 BLM (1)G15&G16 184.9 0 Section 34 BLM (1)G17 257.8 0 Section 35 BLM (1)G17 396.5 0 Section 36 BLM (1)G17 633.3 0 T31N,R7E Section 1 BLM (1)G19 338.0 0 Section 2 BLM (1)G19 634.4 0 Section 3 BLM (1)G19 629.8 0 Section 4 BLM (2)G17&G19 495.8 0 Section 5 BLM (1)G17 332.4 0 Section 6 BLM (1)G17 302.3 0 Section 10 BLM (3)G19 88.1 0 Section 11 BLM (2)G19 311.4 0 Section 12 BLM (2)G19 621.8 0 Section 13 BLM (3)G19 141.4 0 Section 14 BLM (3)G19 01.1 0 T32N,R7E Section 3 BLM (3)G20 246.4 0 Section 4 BLM (3)G18&G20 160.7 0 Section 7 BLM (3)G18 L66.5 0 Section 8 BLM (3)G18 331.0 0 Section 9 BLM (3)G18&G20 517.5 0 )Section 10 BLM (3)G20 31.9 0 I Section 16 BLM (3)G18 141.8 0 Section 17 BLM (3)G18 637.5 0 l Section 18 BLM (3)G18 563.9 0 Section 19 BLM (3)G18 601.8 0 Section 20 BLM (3)G17&G18 640.0 0 Section 21 BLM (3)G17,G18&G20 391.6 0 j Section 22 BLM (3)G19&G20 60.7 0 Section 27 BLM (3)G19 174.4 0 Section 28 BLM (3)G17&G19 624.1 0 I I I 851011 A-16-6 ( t \ ~ -! I -----j I l I ( I I j j I I j I r ( J I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) ·~i u.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE ALREADY CONVEYED* I T32N,R7E (Cont.) Section 29 BLM (3)G17 640.0 0 I Section 30 BLM (1)G17 605.5 0 Section 31 BLM (1)G17 640.5 0 Section 32 BLM (2)G17 640.0 0 ! Section 33 BLM (3)G17&G19 640.0 0 Section 34 BLM (3)G19 423.5 0 Section 35 BLM (3)G19 53.5 0 \ Section 36 BLM (3)G19 11.0 0 T33N,R7E I Section 27 BLM (4)G2l 80.2 0 Section 28 BLM (4)G21 40.0 0 Section 33 BLM (4)G20&G2l 74.0 0 I Section 34 BLM (4)G20&G2l 182.9 0 T30N,R8E -)Section 4 BLM (3)G23 08.2 0 \ T31N,R8E j Section 1 BLM (3)G24 56.9 0 Section 7 BLM (3)G19 386.4 0 I Section 8 BLM (3)G19&G24 535.0 0 Section 9 BLM (3)G24 576.7 0 Section 10 BLM (3)G24 372.9 0 -f Section 11 BLM (3)G24 138.5 0 Section 12 BLM (3)G24 287.9 0 Section 13 BLM (3)G23&G24 598.6 0 Section 14 BLM (3)G23&G24 612.2 0 I Section 15 BLM (3)G23&G24 640.0 0 Section 16 BLM (3)G24&G23 280.3 0 Section 17 BLM (3)GI9,G22&G24 334.7 0 I Section 18 BLM (3)G19 353.1 0 Section 21 BLM (3)G23 182.3 0 Section 22 BLM (3)G23 248.9 0 j Section 23 BLM (3)G23 09.1 0 Section 24 BLM (3)G23 55.1 0 Section 27 BLM (3)G23 06.1 0 Section 28 BLM (3)G23 245.8 0 (Section 33 BLM (3)G23 138.4 0 I 851011 A-16-7 ( I I ~ J J I I I ( j j I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) .~U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE u.S.ACREAGE ALREADY CONVEYED* [T30N,R9E Section 1 BLM (3)G26 143.0 0 I Section 12 BLM (3)G26 105.3 0 Section 13 BLM (3)G26 05.8 0 I T31N,R9E Section 6 BLM (3)G24 49.2 0 I Section 7 BLM (3)G24 00.7 0 Section 17 BLM (3)G24&G25 178.0 0 Section 18 BLM (3)G23&G24 450.2 0 Section 19 BLM (3)G23 175.3 0 -(Section 20 BLM (3)G23&G24 432.8 0 Section 21 BLM (3)G25 499.3 0 Section 22 BLM (3)G25 267.1 0 I Section 23 BLM (3)G25 185.4 0 Section 25 BLM (3)G25 280.1 0 Section 26 BLM (3)G25 316.2 0 ~Section 27 BLM (3)G25 309.3 0 Section 28 BLM (3)G25 107.8 0 Section 36 BLM (3)G25&G26 408.1 0 f T30,R10E Section 6 BLM (3)G26 216.0 0 !Section 7 BLM (3)G26&G27 389.3 0 Section 8 BLM (3)G27 313.7 0 Section 9 BLM (3)G27 170.8 0 ~(Section 10 BLM (3)G27 96.4 0 Section 11 BLM (3)G27 312.9 0 Section 12 BLM (3)G27 254.6 0 Section 13 BLM (3)G27 120.2 0 I Section 14 BLM (3)G27 105.1 0 Section 15 BLM (3)G27 251.1 0 Section 17 BLM (3)G27 77.9 0 I T31N,R10E i Section 31 BLM (3)G26&G27 143.2 0 ( I 851011 A-16-8 ( I I ~ -' -l I I I ! I i j I f I I ,( I ! i I DAMSITES,QUARRYSITES AND RESERVOIR AREAS (Cont'd) ~U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S•ACREAGE ALREADY CONVEYED* J T29N ,RllE Section 1 BLM (3)G29 45.2 0 Section 2 BLM (3)G29 199.2 0 Section 3 BLM (3)G29 222.6 0 Section 4 BLM (3)G29 68.2 0 Section 5 BLM (3)G29 176.6 0 Section 6 BLM (3)G29 135.3 0 Section 9 BLM (3)G29 00.4 0 Section 10 BLM (3)G29 204.5 0 T30N ,RllE Section 7 BLM (3)G27&28 293.8 0 Section 8 BLM (3)G28 01.8 0 Section 17 BLM (3)G28 241.0 0 Section 18 BLM (3)G27&G28 280.4 0 Section 20 BLM (3)G28 445.9 0 Section 21 BLM (3)G28 00.9 0 (- Section 25 BLM (3)G29 21.2 0 Section 28 BLM (3)G28&G29 177.9 0 Section 29 BLM (3)G28&29 480.0 0 Section 32 BLM (3)G29 482.7 0 I Section 33 BLM (3)G29 437.3 0 Section 34 BLM (3)G29 640.0 0 Section 35 BLM (3)G29 471.8 0 I Section 36 BLM (3)G29 35.6 0 -I TOTAL 61,628.0:.7,430:. ~ j i ( ! 851011 A-16-9 ! I ~ i J I ! I i I I I [ I J 1 i I f f ELECTRICAL TRANSMISSION LINE CORRIDOR RIGHT-OF-WAY ACREAGES (Federal Ownership) -I SEWARD MERIDIAN,ALASKA i U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED !T13N ,R2W Section 4 U.S.Army G30 10.21 0 I Section 5 U.S.Army G30 35.51 0 Section 7 U.S.Army G30 37.20 0 Section 8 U.S.Army G30 06.36 0 I Section 18 U.S.Army G30 30.68 0 Section 19 U.S.Army G30 30.66 0 Section 30 U.S.Army G30 30.31 0 I Section 31 U.S.Army G30 04.46 0 T14N,R2W Section 19 U.S.Army G30 33.66 0 Section 20 U.S.Army G30 31.36 0 Section 21 U.S.Army G30 38.29 0 ~Section 22 U.S.Army G30 03.06 0 Section 28 U.S.Army G30 31.12 0 Section 33 U.S.Army G30 36.52 0 !TI4N,3W Section 9 U.S.Army G30 19.56 0 I Section 10 U.S.Army G30 33.29 0 Section 11 U.S.Army G30 05.31 0 Section 13 U.S.Army G30 14.15 0 1 Section 14 U.S.Army G30 44.50 0 Section 24 U.S.Army G30 24.64 0 j T31N,lW Section 3 BLM (3)G39 62.74 0 Section 4 BLM (3)G39 54.77 0 I Section 5 BLM (3)G39 62.74 0 Section 6 BLM (3)G39 61.36 0 j T32N,RIE Section 13 BLM (3)G39 11.77 0 ( Section 23 BLM (3)G39 34.22 0 Section 24 BLM (3)G39 33.23 0 Section 26 BLM (3)G39 07.35 0 i 851011 A-16-10 I ~ I J I I I I I I j l [ I ! ! I I I I ELECTRICAL TRANSMISSION LINE CORRIDOR RIGHT-OF-WAY ACREAGES (Cont'd) ~U.S.ACREAGE SELECTED AND (TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED Section 27 BLM (3)G39 38.03 0 I Section 28 BLM (3)G39 38.03 0 Section 29 BLM (3)G39 37.95 0 Section 30 BLM (3)G39 02.70 0 I T32N,R2E Section 3 BLM (3)G39 41.90 0 !Section 4 BLM (3)G39 20.02 0 Section 8 BLM (3)G39 36.99 0 Section 9 BLM (3)G39 24.88 0 ~!Section 17 BLM (3)G39 07.91 0 Section 18 BLM (3)G39 42.13 0 I T33N,R2E Section 25 (4)G40 34.20 0BLM Section 34 BLM (4)G40 09.28 0 I Section 35 BLM (4)G40 44.90 0 Section 36 BLM (4)G40 07.81 0 ( T32N,R3E Section 2 BLM (3)G40 19.69 0 ( Section 3 BLM (3)G40 37.52 0 Section 11 BLM (3)G40 22.42 0 Section 12 BLM (3)G40 40.01 0 l T32N,R4E Section 7 BLM (3)G40 34.69 0 ~I Sec tion 8 BLM (3)G40 15.67 0 Section 13 BLM (3)G40 37.10 0 Sec tion 14 BLM (3)G40 37.10 0 ! Section 15 BLM (3)G40 35.22 0 Section 16 BLM (3)G40 37.10 0 Section 17 BLM (3)G40 21.43 0 !T32N,R5E Section 18 BLM (3)G40 16.45 0 (Section 19 BLM (3)G40 20.47 0 Section 20 BLM (3)G40 07.68 0 i SEWARD MERIDIAN SUB-TOTAL 1,598.31~ 851011 A-16-11 ( I I ~ J J ( I I l ! -l -I [ I ! ! I I !ELECTRICAL TRANSMISSION LINE CORRIDOR RIGHT-OF-WAY ACREAGES (Cont'd) ~ FAIRBANKS MERIDIAN,ALASKA u.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED [TI2S,R7W I Section 7 AK R.R.G46 0 43.77 Section 17 AK R.R.G46 0 15.71 Section 18 AK R.R.G46 0 14.52 j T7S,R8w Section 24 USAF G48 23.27 0 !Section 25 .USAF G48 5i.86 0 Section 26 USAF G48 51.86 0 I T7S,R7W Section 5 USAF G48 48.93 0 I Section 6 USAF G48 02.76 0 Section 7 USAF G48 51.36 0 Section 8 USAF G48 00.50 0 Section 18 USAF G48 51.86 0 i Section 19 USAF G48 28.59 0 T6s,R7W r Section 4 BLM (4)G49 49.43 0 Section 9 BLM (4)G49 48.70 0 [ Section 16 BLM (4)G49 48.25 0 Section 17 BLM (4)G49 00.45 0 Section 20 BLM (4)G49 34.86 0 l Section 21 BLM (4)G49 13.81 0 Section 29 BLM (4)G49 49.63 0 Section 32 BLM (4)G49 51.78 0 !FAIRBANKS MERIDIAN SUB-TOTAL 681.90+- j TOTAL 2,280.21.:!:. I i 851011 A-16-12 I I ~ I -I J ! I I I I I I I f i j I I I ~--I I ACCESS CORRIDOR RIGHT-OF-WAY ACREAGES ;-1 (Federal Ownership) FAIRBANKS MERIDIAN,ALASKA I U.S.ACREAGE SELECTED AND I TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED T18S,R4W I Section 16 BLM G53 19.80 0 Section 21 BLM G53 24.74 0 Section 22 BLM G53 00.23 0 Sec tion 27 BLM G53 02.09 0 Section 28 BLM G53 23.43 0 Section 33 BLM G53 20.00 0 Section 34 BLM G53 06.41 0 TI9S,R4W I Section 4 BLM G53 29.59 0 Section 5 BLM G53 06.41 0 -I Section 8 BLM G53 29.94 0 Section 16 BLM G53 20.70 0 Section 17 BLM G53 08.41 0 Sec tion 21 BLM.G53 23.57 0 Section 22 BLM G53 04.95 0 Section 27 BLM G53 25.35 0 Section 34 BLM G53 25.61 0 T20S,R4W -]Section 3 BLM G53 25.35 0 Section 10 BLM G53 26.73 0 i Section 14 G53 18.93BLM 0 Section 15 BLM G53 08.25 0 Section 23 BLM G53 22.64 0 Section 24 BLM G54 12.48 0 Section 25 BLM G54 24.86 0 Section 36 BLM G54 24.97 0 T21S,R4W j Section 1 BLM G54 28.28 0 Sec tion 11 BLM G54 34.94 0 J Section 12 BLM G54 03.36 0 Section 14 BLM G54 24.63 0 Section 23 BLM G54 24.38 0 Section 26 BLM G54 24.38 0 i i 851011 A-16-13 J 1 ~ I J j j I j j I I I I I I I I I ACCESS CORRIDOR RIGHT-OF-WAY ACREAGES (Cont'd) ~U.S.ACREAGE SELECTED AND TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED Section 27 BLM G54 00.11 0 I Section 34 BLM G54 25.30 0 Section 35 BLM G54 01.00 0 T22S,R4W I Section 3 BLM G54 24.39 0 Section 10 BLM G54 24.53 0 I Section 15 BLM G54 26.96 0 Section 16 BLM G54 08.55 0 I FAIRBANKS MERIDIAN SUB-TOTAL 686.25+ I SEWARD MERIDIAN,ALASKA T31N,RIW .~Section 3**BLM (1)G59 26.20 0 Section 4**BLM (1)G59 27.92 0 Section 5**BLM (1)G59 12.92 0 ,Section 6**BLM (1)G59 21.80 0 T32N,RIE I Section 23 BLM (3)G58 14.19 0 Section 24 BLM (3)G58 27.63 0 ~1 Section 26 BLM (3)G58 12.91 0 Section 27 BLM (3)G58 29.85 0 Section 28 BLM (3)G58 24.33 0 ! Section 29 BLM (3)G58 13.52 0 T32N,R2E j Section 2 BLM (3)G57 15.01 0 Section 3 BLM (3)G57 28.29 0 Section 4 BLM (3)G57 06.29 0 I Section 8 BLM (3)G58 07.92 0 Section 9 BLM (3)G57&G58 31.71 0 Section 17 BLM (3)G58 21.70 0 I Section 18 BLM (3)G58 13.94 0 Section 19 BLM (3)G5a 13.94 0 I 851011 A-16-14 ! ) ~ j J I I I j I ) j l I I j j I I I I ACCESS CORRIDOR RIGHT-OF-WAY ACREAGES (Cont'd) ~U.S.ACREAGE SELECTED AND ='1 TOWNSHIP/Section OWNER PLATE U.S.ACREAGE*ALREADY CONVEYED T33N,R2E I Section 35 BLM (4)G57 19.42 0 Section 36 BLM (4)G57 26.34 a I T32N,R3E Section 2 BLM (3)G57 01.15 a I Section 3 BLM (3)G57 37.09 a Section 11 BLM (3)G57 28.62 a Section 12 BLM (3)G57 20.09 a I Section 13 BLM (3)G57 07.22 a T32N,4E I Section 11 BLM (3)G56 22.96 a Section 12 BLM (3)G56 16.60 a Section 13 BLM (3)G56 21.23 a I Section 14 BLM (3)G56 10.80 a Section 15 BLM (3)G56 26.86 0 Section 16 BLM (3)G57 24.72 a Section 17 BLM (3)G57 24.75 0 Section 18 BLM (3)G57 24.45 0 T32N,R5E I Section 3 BLM (3)G56 47.60 a Section 4 BLM (3)G56 26.86 a-I Section 5 BLM (3)G56 28.06 0 Section 8 BLM (3)G56 26.46 a Section 10 BLM (3)G56 25.32 a l Section 15 BLM (3)G56 09.51 0 Section 17 BLM (3)G56 09.62 0 Section 18 BLM (3)G56 23.69 a I 863.59+I SEWARD MERIDIAN SUB-TOTAL -) TOTAL 1,549.84+ 851011 A-16-15 J ) 17 -REFERENCES Commonwealth Associates Inc.1982.Anchorage-Fairbanks Transmission Intertie Route Selection Report.Prepared for Alaska Power Authority,Anchorage,Alaska. Harza-Ebasco Susitna Joint Venture.1983.Watana Development Winter 1983 Geotechnical Exploration Program.Prepared for Alaska Power Authority,Anchorage,Alaska. 851011 A-17-1 J ) ~ I ) I I ] i I I ) ) 1 J I ..~ I I -, TABLES _I TABLE A.l:PERTINENT PROJECT DATA l- (Page 1 of 4) Item Stage I Watana Stage Ill/ Devll Canyon Stage IIll/ Watana Devil-Canyon Hydrology -Average River Flow (cfs) -Peak Flood Inflows (cfs) PMF 1O,OOO-year 50-year •25-year -Peak Flood Flows through the Dam (cfs) PMF 50-year Reservoir Characteristics -Normal Max1mum Opera~1ng Level ~/ Maximum Level,PMF ~I Minimum Operating Level ~/ Area at NMOL (acres) Length at NMOL (miles) Total Storage (acre-feet) Live Storage (acre-feet) Maximum Allowable Surcharge Level/for 50-year Flood ~ Average Tailwater ~/ Project Outputs Dependable Plant Capability (December-January)(MW) -Nominal Plant Capability (MW)~/ -Annual Generation (GWh) •Firm •Average 8,050 9,160 326,000 358,000 with Watana 362,000 without Watana 174,000 184,000 without Watana 89,500 46,000 with Watana 94,800 without Watana 79,800 44,600 with Watana 84,500 without Watana 302,300 351,000 with Watana 283,600 34,000 42,000 with Watana 33,900 2,000 1,455 2,185 2,017.1 1465.6 2,199.3 1,850 1,405 2,065 19,900 7,800 38,000 39 26 48 4.3 x 10 6 1.1 x 10 6 9.5 x 10 6 2.4 x 10 6 0.35 x 10 6 3.7 x 10 6 2,014 1,456 2,193 1,455 850 1,455 360 600 1,020 440 680 1,110 1,950 4,490.£~5,720.£~ 2,400 4,750.£6,900.£ 339,000 with Watana 362,000 without Watana 44,600 with Watana (Yr 2008) 35,300 with Watana (Yr 2020) 94,800 without Watana 43,200 with Watana (Yr 2008) 31,600 with Watana (Yr 2020) 84,500 without Watana 333,000 with Watana 42,000 with Watana 1,463.1 N A.-Not Applicable11WatanaStageIdata as shown applies both before and after construction of Devil Canyon,except where indicated for Stage III.Devil Canyon Stage II data,as shown,applies both / before and after construction of Watana Stage III except where indicated otherwise for Stage III. 1/Total generation from Watana and Devil Canyon. 1/Contour elevation (feet above mean sea level) ~At average operating head I ) -J ,I J J ,J J J I J J J I TABLE A.l (Page 2 of 4) Item Dams -Type -Crest Elevation 1/ -Crest Length (ft) -Height Above Foundation 1/ -Crest Width (ft) -Upstream Slope (H:V) -Downstream Slope (H:V) -Allowance for Settlement (ft) Top of Parapet 1/ Stage I Watana Ea r th/Rockfi 11, Inclined Core 2,027 2,700 702 35 2.4:1 2:1 2 N.A. Stage Ill.! Dev11 Ca nyon Concrete Arch (Earth/Rockfill Saddle) 1,463 (1472) 1,650 (950) 646 (245) 20 (35) N.A.(2.4:1) N.A.(2:1)o (2) 1,466.0 --L Stage IIlI/ Watana Devir-canyon Earth/Rockfill Central Core 2,210 4,100 885 35 2.4:1 2:1 5 N.A. Diversion -Recurrence Interval of Design Flood (yrs) -Cofferdams Type •Upstream Crest Elevation 1/ •Downstream Crest Elevation 1/ •Maximum U/S Water Level for Design Flood 1/ -Tunnels •Number/Type •Diameter (ft) ·Capacity for Design Flood (cfs) Outlet Facilities -Control Structures -Diameter (in) -Water Passage Diameter (ft) -Ca pa city (c fs ) N.A.-Not Applicable 1j See first page of this Table. -See first page of this Table. 50 Earth & Rockfill 1,550 1,495 1,532 2 -Circular, Concrete-Lined 36 77 ,000 6-Fixed Cone Valves 78 28 24,000 25 Earth & Rockfill 947 898 944 1 -Horseshoe, Concrete-Lined 35.5 43,300 7-Fixed Cone Valves 4-102,3-90 8.5/7.5 42,000 N.A. N.A. 1,495 N.A. N.A. N.A. 6-Fixed Cone Valves 78 28 30,000 N.A. N.A. N.A. N.A. N.A. N.A. N.A. I I ,~ ) I I I I I j I j -j I j j I ) I TABLE A.I (Page 3 of 4) Item Stage I Watana Stage Ill/ Dev11 Canyon --L Stage IIll/ Watana Dev11~anyon Spillway -Capac1ty at 50-yr flood surcharge (cfs) Capacity at PMF surcharge (cfs) Control Structure •Type Crest Elevation 1/ •Gates Number Dimensions (HxW,ft 7) Top of Gate Level 3 -Chute Width (ft) -Energy Dissipation 258,000 240,000 278,400 309,000 Gated agee Gated agee 1,950 1,398 3 3 64 x 44 58 x 48 2,014 1,456 164 x 120 176 x 150 Flip bucket Flip bucket 220,000 259,600 Gated agee 2,135 3 64 x 44 2,199 164 x 120 Flip bucket 291,000 Power Intakes Intake Structures Number of Levels ·Number of Shutters per Level •Dimensions of Shutters (HxW,ft) -Control Gates •Number •Dimensions ~HXW3/ft) Invert Elevat10n - Power Tunnels -Number -Type -Concrete-Lined Diameter (ft) Penstocks -Number -Type -Diameter (ft) Concrete-lined Steel-lined 1/See first page of this Table. 1/See first page of this Table. Multi-level,Gated 5 4 25 x 24 4 24 x 12 1,800 2 Inclined/Horizontal 24 4 Horizontal 18 15 Multi-level,Gated 2 4 20 x 34+ +4 24 x 20 1,365 See Penstocks See Pens tocks See Penstocks 4 Inclined/Horizontal 20 15 Multi-level,Gated 4 6 25 x 24 6 24 x 12 1,800 &2012 3 Inc1ined/Horizona1 24 6 Horizontal 18 15 I I ,-) I I I ) I I I ) J -j J I ] ) ] I TABLE A.1 (Page 4 of 4) Item Powerhouses -Type -Cavern Size (L x W x H,ft) -Turbine (No.and Type) -Speed (rpm) -Nominal Unit Capability at Average Operating Head (MW) -Maximum Unit Capability •Net Head (ft) •Flow (ds) •Output (MW) -Minimum Unit Capability Net Head (ft) Flow (cfs) Output (MW) -Generators Type Rated Capacity (MVA) Power Factor Voltage (kV) Frequency (Hz) Speed,rpm -Transformers Location ·Cavern Size (L x Wx H,ft) Number Rating (MVA) Voltage (kV) Tailrace Tunnels -Number/Type -Diameter (ft) -Surge Chamber Size (L x Wx H,ft) N.A.-Not Applicable 1/Se~firQt page of this TablQ. --- Stage I Watana Underground 365 x 78 x 136 4 Vertical Francis 257 110 537 3,080 125 384 2,310 65 Vertical Synchronous 223 Air Cooled 0.9 15 60 257 Upstream Gallery 308 x 45 x 40 6 150 15-345/1.73 Single Phase 1 -Horseshoe, Concrete-Lined 34 250 x 50 x 150 Stage nl/ Dev11 Canyon Underground 360 x 74 x 126 4 Vertical Francis 225 170 600 3,790 173 545 3,615 150 Vertical Synchronous 192 Air Cooled 0.9 15 60 225 Upstream Gallery 446 x 43 x 40 12 70 15-345/1.73 Single Phase 1 -Horseshoe Concrete-Lined 38 240 x 75 x 190 -L Stage nII/ Watana---UeviT Canyon Underground 520 x 78 x 136 6 Vertical Francis 257 185 719 3,800 200 600 3,310 150 Vertical Synchronous 223 Air Cooled 0.9 15 60 257 Upstream Gallery 414 x 45 x 40 9 150 15-345/1.73 Single Phase 2 -Horseshoe Concrete-Lined 34 445 x 50 x 150 i ) ~ i I i I ) I ) I I -j I -L TABLE A.l (Page 4 of 4) Item Powerhouses -Type -Cavern Size (L x W x H,ft) -Turbine (No.and Type) -Speed (rpm) -Nominal Unit Capability at Average Operating Head (MW) Maximum Unit Capability ·Net Head (ft) •Flow (cfs) •Output (MW) -Minimum Unit Capability Net Head (ft) Flow (cfs) Output (MW) -Generators Type Rated Capacity (MVA) Power Factor Voltage (kV) Freq uency (Hz) Speed,rpm -Transformers Location •Cavern Size (L x W x H,ft) Number Rating (MVA) Voltage (kV) Tailrace Tunnels -Number/Type -Diameter (ft) -Surge Chamber Size (L x Wx H,ft) N.A.-Not Applicable 1/Sea firQt PQge of this Table. Stage I Watana Underground 365 x 78 x 136 4 Vertical Francis 257 110 537 3,080 125 384 2,310 65 Vertical Synchronous 223 Air Cooled 0.9 15 60 257 Upstream Gallery 308 x 45 x 40 6 150 15-345/1.73 Single Phase 1 -Horseshoe, Concrete-Lined 34 250 x 50 x 150 Stage nIl Dev11 Canyon Underground 360 x 74 x 126 4 Vertical Francis 225 170 600 3,790 173 545 3,615 150 Vertical Synchronous 192 Air Cooled 0.9 15 60 225 Upstream Gallery 446 x 43 x 40 12 70 15-345/1.73 Single Phase 1 -Horseshoe Concrete-Lined 38 240 x 75 x 190 l- Stage nIll Watana --DeviT Canyon Underground 520 x 78 x 136 6 Vertical Francis 257 185 719 3,800 200 600 3,310 150 Vertical Synchronous 223 Air Cooled 0.9 15 60 257 Upstream Gallery 414 x 45 x 40 9 150 15-345/1.73 Single Phase 2 -Horseshoe Concrete-Lined 34 445 x 50x 150 __I i ) ~ I 1 I I ) I ) ) I l I I I ~ I FIGURES zo i=c(..(.).< 9 au ~a:~~o I&. a:a. cw CIJ ~oa:a. i- I -\ \ \ \ \ \ J \ ARLIS, Alaska Resources Library &Information Services lUlchorage.AJaska BIBLIOGRAPHY LIST OF TABLES LIST OF FIGURES 1 -INTRODUCTION E-2-1 2 -BASELINE DESCRIPTION E-2-2 2.1 -Sus itn a Ri ver Water Qual Uy E-2-3 2.2 -Susitna River Morphology E-2-5 2.3 -Susitna River Water Quality E-2-10 2.4 -Baseline Ground Water Conditions ;..E-2-23 2.5 -Existing Lakes,Reservoirs,and Streams E-2-24 2.6 -Existing Instream Flow Uses E-2-25 2.7 -Access Pl an .-E-2-29 2.8 -Transmission Corridor E-2-29 11'\ 1'1 d-S ,cs ~ Fl-.\i-1 no.3Y 3 0 d. CHAPTER 2VOLUME1 EXHIBIT E SUSITNA HYDROELECTRIC PROJECT WATER USE AND QUALITY TABLE OF CONTENTS 3 -PROJECT IMPACT ON WATER QUALITY AND QUANTITy E-2-31 3.1 -Proposed Project Reservoirs E-2-31 3.2 -Watana Development E-2-31 3.3 -Devi 1 Canyon Development E-2-68 3.4 -Access Pl an I[T1pacts E-2-86 3.5 -Transmissio~Corridor Impacts E-2-88 4 -AGENCY CONCERNS AND RECOMMENDATIONS E-2-89 5 -MITIGATION ENHANCEMENT AND PROTECTIVE MEASURES E-2-90 5.1 -Introduction 'E-2-90 5.2 -Construction E-2-90 5.3 -Mitigation of Watana Impoundment Impacts E-2-90 5.4 -Mitigation of Watana Operation Impacts E-2-91 5.5 -Mitigation of Devil Canyon Impoundment Impacts E-2-92 5.6 -Mitigation of Devil Canyon/Watana Operation E-2-92 , Ij,,I H I I 1 j H II 11 I I I I I I I I ) I I j j I I ~ I I. ,-{ , I ('i') 00 ('i') "~ ooo LO LO "('i') ('i') LIST OF TABLES 'E.2.1 -Gaging Station Data E.2.2 -Basel ine Monthly Flows (cfs) E.2.3 -Instantaneous Peak Flows of Record E.2.4 -Comparison of Susitna Regional Flood Peak Estimates With USGS Methods for Gold Creek E.2.5 -Susitna River Reach Definitions E.2.6 -Detection Limits for Water Quality Parameters E.2.7 -Parameters Exceeding Criteria by Station and Season E.2.8 -1982 Turbidity Analysis of the Susitna,Chulitna,and Talkeetna Rivers Confluence Area E.2.9 -Significant Ion Concentrations E.2.10 -Streams to be Partially or Completely Inundated by Watana Reservoir (El 2,185) E.2.11 -Streams to be Partially or Completely Inundated by Devil Canyon Reservoir (El 1,455) E.2.12 -Downstream Tributar ies Potent i ally Impacted by Proj ect Operat ion E.2.13 -Summary of Water and Ground Water Appropriations in Equ iv al ent Flow Rates E.2.14 -Susitna River -Limitations to Navigation E.2.15 -Estimated Low and High Flows at Access Road Stream Crossings E:2.16 -Available Streamflow Records fo'r Major Streams Crossed by Transmission Corridor E.2.17 -Downstream Flow Requirements at Gold Creek E.2.18 -Watan a In flow and Out flow for Fi 11 i ng Cases E.2.19 -Flows at Gold'Creek During Watana Fill ing E.2.'20 -Monthly Average Pre-Project and Watana Fill ing Flows at Gold Creek,Sunshine and Susitna Stations E.2.21 -Post-Project Flow at Watana (cfs) E.2.22 -Monthly Maximum,Minimum,and t~ean Flows at Watana E.2.23 -Pre-ProJect Flow at Gold Creek (cfs) E.2.24 -Post-Project Flows at Gold Creek E.2.25 -Monthly Maximum,Minimum,and Mean Flows at Gold Creek E.2.26 -Pre-Project Flow at Sunshine (cfs) E.2.27 -Post-Project Flow at Sunshine (cfs) E.2.28 -Pre-Project Flow at Susitna (cfs) E.2.29 -Post-Project Flow at Susitna E.2.30 -Monthly Maximum,Minimum,and Mean Flows at Sunshine E.Z.31 -Monthly Max imum,Miniml11l,and Mean Flows at Susitna E.2.32 -Pre-Project Flow at Watana (cfs) E.2.33 -Pre-Project Flow at Devil Canyon (cfs) E.2.34 -Post-Project Flow at Watana (cfs) E.2.35 -Post-Project Flow at Devil Canyon (cfs) E.2.36 -Post-Project Flows at Gold Creek (cfs) E.2.37 -Monthly Max imum,Mi n imum,and Me an Flows at Dev il Canyon E.2.38 -Post-Project Flow at Sunshine (cfs) E.2.39 -Post-Project Flow at Susitna (cfs) ARLIS Alaska Resources Library &InformatiOn Services Anchorage,A.laska '-I -I I -J I I ../.:-~J l LIST OF FIGURES Figure E.2.1 -Data Collection Stations Figure E.2.2 -Annual Flood Frequency Curve,Susitna River Near Denali Figure E.2.3 -Annual Flood Frequency Curve,Susitna River Near Cant well Figure E.2.4 -Annual Flood Frequency Curve,Susitna River at Gold Creek Figure E.2.5 -Annual Flood Frequency Curve,Maclaren River· near Paxson Figure E.2.6 -Annual Flood Frequency Curve,Chulitna River near Tal keetna Figure E.2.7 -Annual Flood Frequency Curve,Talkeetna River near Talkeetna Figure E.2.8 -Annual Flood Frequency Curve,.Skwenta River near Skwentna Figure E.2.9 -Design Dimensionless Regional Frequency Curve Annual Instantaneous Flood Peaks Figure E.2.10 -Watana Natural Flood Frequency Curve Figure E.2.11 -Devil Canyon Natural Flood Frequency Curve Figure E.2.12 -Flood Hydrographs,May -July Figure E.2.13 -Flood Hydrographs,Aug -Oct Figure E.2.14 -Monthly and Annual Flow Duration Curves Susitna River at Gold Creek,Susitna River near Cantwell,Susitna River near Denali Figure E.2.15 -Monthly and Annual Flow Duration Curves Maclaren River at Paxson Figure E.2.16 -Monthly and Annual Flow Duration Curves Susitna River at Susitna Station Figure E.2.17 -Monthly and Annual Flow Duration Curves Talkeetna River near Talkeenta Figure E.2.18 -Susitna River at Gold Creek,Low-Flow Frequency Curves -May \ -} LIST OF FIGURES (Cont'd) Figure E.2.19 -Susitna River at Gold Creek,Low-Flow Frequency Curves -June Figure E.2.20 -Susitna River at Gold Creek,Low-Flow Frequency Curves -July and August Figure E.2.21 -Susitnc.River at Gold Creek,Low-Flow Frequency Curves -September and October ·-F-ig.ure--::E.2.22 -Susitna River at Gold Creek,High-Flow Frequency Curves -May Figure E.2.23 -Susitna River at Gold Creek,High-Flow Frequency Curves -June Figure E.2.24 -Susitna River at Gold Creek,High-Flow Frequency Curves -July and August Figure E.2.25 -Susitna River at Gold Creek,High-Flow Frequency Curves -September and October Figure E.2.26 -Susitna River Water Temperature -Summe~1980 Figure E.2.27 -Susitna River Water Temperature -Summer 1981 Figure E.2.28 -Susitna River at Watana,Weekly Average Water Temperature -1981 Water Year Figure E.2.29 -~usitna River -Water Temperature Gradient Figure E.2.30 -Data Summary -Temperature Figure E.2.31 -Location Map for 1982 Midwinter Temperature Study Sites Figure E.2.32 -Comparison of Weekly Dial Surface Water Temperature Variations in Slough 21 and the Mainstream Susitna River at Portage Creek (adapted from ADF&G 1981). Figure E.2.33 -Susitna River,Portage Creek and Indian River Water Temperatures Summer 1982 Figure E.2.34 -Data Summary -Total Suspended Sed iments Figure E.2.35 -Suspended Sediment Rating Curves,Upper Susitna River Bas in Figure E.2.36 -Suspended Sediment Size Analysis,Susitna River l r [ [ I.. 1 [ L I L I ~! I ---l 1. } l ); ~\ !J i I \ I I ( I,1I) LIST OF FIGURES (Cont'd) Figure E.2.37 -Data Summary -Turbidity Figure E.2.38 -Turbidity vs Suspended Sediment Concentration Figure E.2.39 -Data Summary -Total Dissolved Solids Figure E.2.40 -Data Summary -Conductivity Figure E.2.41 -Data Summary -Chloride ...........-----..,...- Figure E.2.42 -Data Summary -Sulfate Figure E.2.43 -Data Summary -Calcium Figure E.2.44 -Data Summary -Magnesium (d) Figure E.2.45 -Data Summary -Sodium (d) Figure E.2.46 -Data Summary -Potassium (d) Figure E.2.47 -Data Summary -PH Figure E.2.48 -Data Summary -Hardness Figure E.2.49 -Data Summary -Alkalinity Figure E.2.50 -Data Summary -True Color Figure E.2.51 -Data Summary -Aluminum (d) Figure E.2.52 -Data Summary -Aluminum (t) Figure E.2.53 -Data Summary -Cadmium (d) Figure E.2.54 -Data Summary -Cadmium (t) Figure E.2.55 -Data Summary -Copper (d) Figure E.2.56 -Data Summary -Copper (t) Figure E.2.57 -Data Summary -Iron (d) Figure E.2.58 -Data Summary -Iron (t) Figure E.2.59 -Data Summary -Lead (d) Figure E.2.60 -Data Summary -Lead (t) Figure E.2.61 -Data Summary -Manganese (d) ~l } ,I I } '), LIST OF FIGURES (Cont'd) Figure E.2.62 -Data Summary -Manganese (t) Figure E.2.63 -Data Summary -Mercury (d) Figure E.2.64 -Data Summary -Mercury (t) Figure E.2.65 -Data Summary -Nickel (d) Figure E.2.66 -Data Summary -Nickel (t) ~-----Figure E.2.67 -Data Summary -Zinc (d) Figure E.2.68 -Data Summary -Zinc (t) Figure E.2.69 -Data Summary -Oxygen,Di ssolved Figure E.2.70 -Data Summary -0.0.,%Saturation Figure E.2.71 -Data Summary -Nitrate Nitrogen Figure E.2.72 -Data Summary -Ortho Phosphate Figure E.2.73 -Location of Township Grids in the Susitna River Basin Figure E.2.74 -Watana Borrow Site Map Figure E.2.75 -Cross-Section Number 32 RM 130 Figure E.2.76 -Watana Water Levels and Gold Creek Flows During Reservoir Filling Figure E.2.77 -Watana Outflow Frequency Curve During Watana Impoundment (to be completed later) Figure E.2.78 -Flow Variability,Natural and Filling Conditions Di scharge at Gold Creek Figure E.2.79 -Schematic of the Effect of the Susitna River on Typical Tributary Mouth Figure E.2.80 -Eklutna Lake,Light Extinction In Situ Measurements Figure E.2.81 -Slough 9 Thalwg Profile and Susitna River Mainstem Water Surface Profiles Figure E.2.82 -Watana Reservoir Water Levels (Watana Alone) Figure E.2.83 -Watana Hydrological Data -Sheet 2 [ [ [ l l L l l t ,;I',~", l ) 1 } 1 ,) i 1\,J I' I I LIST OF FIGURES (Cont'd) Figure E.2.84 -Watana Inflow Flood Frequency Figure E.2.85 -Monthly and Annual Flow Duration Curves,Susitna River at Watana Figure E.2.86 -Monthly and Annual Flow Duration Curves,Susitna River at Gold Creek Figure E.2.87 -Monthly and Annual Flow Duration Curves,Susitna River at Sunsh i ne Figure E.2.88 -Monthly and Annual Flow Duration Curves,Susitna River at Susitna Station Figure E.2.89 -Water Temperature Profiles,Bradley Lake,Alaska • Figure E.2.90 -Multiport Intake Levels Figure E.2.91 -Watana Reservoir Temperature Profiles Figure E.2.92 -Reservoir Temperature Modeling,Outflow Temperature~ Figure E.2.93 -Devil Canyon,Flood Frequency Curve Figure E.2.94 -Watana Reservoir Water Levels (Watana and Devi 1 Canyo'n in,Oper at i on) Figure E.2.95 Dev i 1 Canyon Reservoir Water Level s Figure E.2.96 -Dev i 1 Canyon Hydrological Data Figure E.2.97 -Monthly and Annual Flow Duration Curves,Talkeetna River Near Talkeetna)Chulitna River near Talkeetna Figure E.2.98 -Monthly and Annual Flow Duration Curves,Susitna River ~t Gold Creek Figure E.2.99 -Monthly and Annual Flow Duration Curves,Susitna River at Sunshine Figure E.2.100-Monthly and Annual Flow Duration Curves,Susitna River at Susitna Station Figure E.2.101-Temporal Variation in Salinity Within Cook Inlet Near the Susitna River Under Pre-and Post-Susitna Hydroelectric Project Conditions ,) J \ I ! II I I 2 -REPORT ON WATER USE AND QUALITY 1 -INTRODUCTION The Report on Water Use and Quality is divided into four basic sec- tions:baseline conditions,project impacts,agency concerns and recom- mendations,and mitigatives,enhancement,and protective measures. Within the sections on baseline conditions and project impacts,emp- hasis is placed on flows,water quality parameters,ground water condi- t ions and instream flow uses.The importance of flows cannot be over- stressed.Flows are important to all instream uses.Mean flows,flood flows,low flows and flow variability are discussed. The primary focus of the water qual ity discussion is on those para- meters determined most critical for the maintenance of fish populations and other aquatic organisms.Detailed discussions are presented on water temperature both in the mainstem Susitna River and in the sloughs downstream of Devil Canyon,ice,suspended sediment in the reservoirs and downstream,turbidity,dissolved oxygen,nitrogen supersaturation and nutri ents.These parameters have prev ious 1y been ident ifi ed as areas of greatest concern. Mainstem-slough groundwater interaction 90wnstream of Devil Canyon is important to salmonid spawning in sloughs and is discussed. The primary instream flow uses of the Susitna are for fish,wildlife and riparian vegetation.As these are fully discussed in Chapter 3, they are only briefly discussed in this Chapter.However,other in- stream flow uses including navigation and transportation,waste assimi- lative capacity and freshwater recruitment to estuaries are discussed. Since minimal out of river use is made of the water,Talkeetna being the only town located near the river and not relying on the river for its water supply,only limited discussions have been presented on out of river uses. Proj ect impacts have been separated by devel or:ment.Impacts,asso- ciated with each develor:ment,are presented in chronological order: construction,impoundment and operation. The agency concerns and recommendations received to date are sum- mar i zed. The mitigation plan incorporates the engineering and construction meas- ures necessary to minimize potential impacts,·given the economic and engineering constraints. E-2-1 I I Y l ) I \ I-Ir I 2 -BASELINE DESCRIPTION The entire drainage area of the Susitna River is about 19,400 square miles,of which the upper basin above Gold Creek comprises approximate- ly 6160 square miles (Figure E.2.1).Three glaciers in the Alaska Range feed forks of the Sus itna Ri ver,fl ow southward for about 18 miles and then join to form the Susitna River.The river flows an additional 55 miles southward through a broad valley where much of the coarse sed iment from the gl ac iers settl es ou~.The river then flows westward about 96 miles through a narrow valleY,with constrictions at the Devil Creek and Devil Canyon areas,creating violent rapids.Num- erous small,steep gradient,clear-water tributaries flow to the Susitna in this reach of the river.Several of these tributaries cas- cade over waterfall s as they enter the gorge.As the Sus itna curves south past Gold Creek,12 miles downstream of the mouth of Devil Canyon,its gradient gradually decreases.The river is joined about 40 miles beyond Gold Creek in the vicinity of Talkeetna by two major trib- utaries,the Chulitna and Talkeetna Rivers.From this confluence,the Susitna flows south through braided channels about 97 miles until it empties into Cook Inlet near Anchorage,approximately 318 miles from its source. The Susitna River is typical of unregulated northern glacial rivers with high,turbid summer flow and low,clear winter flow.Runoff from snownelt and rainfall in the spring causes a rapid increase in flow in May from the low discharges experienced throughout the winter.Peak annual floods usually occur during this period. Associated with the higher spring flows is a 100 fold increase in sedi- ment transport which persists throughout the summer.The large sus- pended sediment concentration in the June to September time period causes the river to be highly turbid.Glacial sllt contributes most of the turbidity of the river when the glaciers begin to melt in late spring.. Rainfall related floods often occur in August and early September,but generally these floods are not as severe as the spring snow melt floods. As the weather begins to cool in the fall,the glacial melt rate de- creases and the flows in the river gradually decrease correspondingly. Because most of the river suspended sediment is caused by glacial melt, the river also begins to clear.Freeze up normally begins in October and cont inues to progress up river through earl y December.The ri ver breakup generally begins in late April or early May near the mouth and progresses upstream with breakup at the damsite occurring in mid-May. E-2-2 ,I ,i' ~ -l I tr-~....-- l f) ( ~ f I .I --I 9 I 2.1 -Susitna River Water Quality (a)Mean Monthly and Annual Flows Continuous historical streamflow records of various record length (8 to 32 years)exist for gaging stations on the Susitna River and its tributaries:Gages are located at Denali,Cantwell (Vee Canyon),Gold Creek and Susitna Station on the Susitna River;on the Maclaren River near Paxson;Chulitna Station on the Chulitna River;Talkeetna on the Talkeetna River;and Skwentna on the Skwentna River.In 1981 a USGS gaging station was constructed at Sunshine on the Susitna River;however,the streamflow record is of such a short duration it has not been used in most of the hydrologic analysis.Statistics on river mile,drainage area and years of record are shown in Table E.2.1.The station locations are illustrated in Figure E.2.1. A complete 32 year streamflow data set for each gaging station was generated through a correlation analysis,whereby missing mean monthly flows were estimated (Acres 1982a).The resultant monthly and annual maximum,mean and minimum flows for the 32 year record are presented in Table E.2.2. Mean monthly flows at the.Watana and Devil Canyon damsites were estimated using a linear drainage ar-ea-flow relationship between the Gold Creek and Cantwell gage sites.The resultant mean,maxi- mum and minimum monthly flows are also provided in Table E.2.2. Comparison of flows indicates that 40 percent of the streamflow at Gold Creek originates above the Denali and Maclaren gages.It is in this catchnent that the glaciers which contribute to the flow at Gold Creek are located. The Susitna River above Gold Creek contributes 19 percent of the mean annual flow measured at Susitna Station near Cook Inlet.The Chulitna,and Talkeetna Rivers contribute 20 and 10 percent of the Susitna Station flow respectively.The Yentna provides 40 percent of the flow,with the remaining 11 percent originating in miscel- laneous tributaries. The variation between summer and winter flows is greater than a 10 to 1 ratio at all stations.This large seasonal difference is due to the characteristics of the basin.Glacial melt,snownelt,and rainfall provide the majority of the annual river flow during the summer.At Gold Creek,for example,88 percent of the annual streamflow occurs during the summer months of May through September. The maximum and minimum monthly flows for the months of May through September indicate a high flow variability at all stations on a year to year basis. E-2-3 I r f I ( [ [ [ l l. l 1 L "\ I. J I t ) r ) ~ II I j ,I, (b)Floods The most commong causes of floods in the Susitna River Basin are snownelt or a combination of snownelt and rainfall over a 1 arge area.This type of flood occurs between May and July with the majority occurring in June.Floods attributable to heavy rains have al so occurred in August,September or October.These floods are augmented by snownelt"from higher elevations and glacial run- off.Table E.2.3 presents selected flood peaks at four gaging stations.Figures E.2.2 to 1:.2.8 illustrate annual instantaneo.us flood frequency curves for individual stations. A regiQnal-..---flood frequency analysis was conducted using the re- corded floods in the Susitna River and its principal tributaries (R&M,1981a).The resulting dimensionless regional frequency curve is depicted in Figure E.2.9.A stepwise multiple linear regress ion computer program was used to rel ate the mean annual instantaneous peak flow to the physiographic and cl imatic charac- terist ics of the drainage basins.The mean annual instantaneous peak flows for the Watana and Devil Canyon damsites were computed to be 40,800 cubic feet per second (cfs)and 45,900 cfs respec- tively.The regional flood frequency curve was compared to the station frequency curve at Gold Creek (Table E.2.4).As the Gold Creek station frequency curve yielded more conservative flood peaks (i.e.larger),it was used to estimate flood peaks at the Watana and Devil Canyon damsites for floods other than the mean annual flood.The flood ,frequency curves for Watana and Devil Canyon are presented in Figures E.2.10 and E.2.11. Dimensionless flood hydrographs for the Susitna River at Gold Creek were developed for the May -July snownelt floods and the August -October rainfall floods using the five largest Gold Creek floods occurring in each period (R&M,1981a).Flood hydrographs for the 100,500,and 10,000 year flood events were constructed using the appropriate flood peak and the dimensionless hydrograph. Hydrographs for the May -July and August -October flood periods are illustrated in Figures E.2.12 and E.2.13 respectively. Probable maximum flood (PMF)studies were conducted for both the' Watana and Devil Canyon damsites for use in the design of project spillways and related facilities.These studies which are based on Susitna Basin cl imatic data and hydrology,indicate that the PMF peak at the Watana damsite is ~26,000 cfs. (c)Flow Variability The variabil ity of flow in a river system is important to all instream flow uses.To illustrate the variability of flow in the Susitna River,monthly and annual flow duration curves showing the proportion of time that the discharge equals or exceeds a given value were developed for the four mainstem Susitna River gaging stations (Denal i,Cantwell,Gold Creek and Susitna Stat ion)and three major tributaries (Maclaren,Chulitna,and Talkeetna Rivers) (R&M,1982a).These curves which are based on mean daily flows are illustrated on Figures E.2.14 through E.2.17. E-2-4 r,I l ,-( ~,\ ( 1'1 I \ I,/ The shape of the monthly and annual flow duration curves is Slml- lar for each of the stations and is indicative of flow from north- ern glacial rivers.Streamflow is low in the winter months,with little variation in flow and no unusual peaks.Groundwater con- tributions are the preliminary source of the small but relatively constant winter flows.Flow begins to increase slightly in April as breakup approaches.Peak flows in May are an order of magni- tude greater than in April.Flow in May also shows the greatest variation for any month,as low flows may continue into May before the high snowmelt/breakup flows occur.June has the highest peaks and the highest median flow.The months of July and August ·have· relatively flat flow duration curves.This situation is ·indica- tive of rivers with strong base flow characteristics,as is the case-on tfIe Susitna with its contributions from snowmelt and gla- cial melt during t.he summer.More variability of flow is evident in September and October as cooler weather becomes more prevalent. The I-day,3-day,7-day and 15-day high and low flow values were determined for each month from May through October for the periods of record at Gold Creek,Chulitna River near Talkeetna,Talkeetna River near Talkeetna and Susitna River at Susitna Station (R&M, 1982a).The high and low flow values are presented for Gold Creek in the form of frequency curves in Figures E.2.18 through E.2.21. May showed the most variability.It is the month when either low winter flows or high breakup flows may occur and thus significant changes occur from year to year.June and July generally exhibited less variability than the late summer months.Flow variability increased in the August through October period.Heavy rainstorms often occur in August,with 28 percent of the annual floods occurring in this month. 2.2 -Susitna River Morphology (a)Mainstem The Sus itna Ri ver ori gi nates in the gl aci ers of the southern slopes of the central Alaskan Range,flowing 318 miles to its mouth at Cook Inlet. The headwaters of the Susitna River and its major upper tribu- taries are characterized by broad braided gravel floodplains below the gl aci ers,with several meltstreams exi t i ng from beneath the gl aci ers before they combi ne further downstream.The West Fork Susitna River joins the main river about 18 miles below Susitna Glacier.Below the West Fork confluence,the Susitna River becomes a split-channel configuration with numerous islands.The river is generally constrained by low bluffs for about 55 miles. The Maclaren River,a significant glacial tributary,and the Tyone River,which drains Lake Louise and the swampy lowlands of the southeastern upper basin,both enter the Susitna Ri ver from the east.Below the confluence with the Tyone River,the Susitna E-2-5 f r , I I l 1 I r I l [ l ! J River flows west for 96 miles through steep-walled canyons before reaching the mouth of Devil Canyon.The river has a high gradient through this reach and includes the Watana and Devil Canyon Dam- sites.It is primarily a single channel with intermittent is- lands.Bed material primarily consists of large grravel cobbles. The mouth of Devil Canyon,at River Mile (RM)149 forms the lower limit of this reach. Between Dev il Cal1yon and the mouth at Cook In 1et,the ri ver has been subdivided into nine separate reaches..These reaches are identified in Table E.2.5,together with the average slope and predominent channel pattern.These reaches are discussed in more detail below.~-....... RM 149 to RM 144 Through this reach,the Susitna flows predominately in a single channel confined by valley walls.At locations where the valley bottom widens,depostion of gravel and cobble has formed mid-chan- nel or side-channel bars.Occasionally,a vegetated island or fragmentary fl oodpl ain has formed with el ev at ions above normal flood levels,and has become vegetated.Presence of cobbles and boulders in the bed material aids in stabil ization of the channel geometry. RM 144 to RM 139 A broadening of the valley bottom throug"h this reach has allowed the river to develop a split channel with intermittent;well- vegetated isl ands.A correl ation exists between bankfull stage and mean-annual flood.Where the main channel impinges on valley walls or terraces,a cobble armor layer has developed with a top elevation at roughly bankfull flood stage.At RM 144,a perigla- cial alluvial fan of coarse sediments confines the river to a single channel.. RM 139 to RM 129.5 This river reach is characterized by a well defined split channel configuration.Vegetated isl ands separate the main channel from side channels.Side channels occur frequently in the alluvial floodplain and receive Susitna water only at flows above 15,000 to 20,000 cfs.Often,valley bottom springs flow into sloughs. There is a good correl ation between bankfull stage and the mean annual flood. Where the main channel impinges valley walls or terraces,a cobble armor layer has developed with a top elevation at roughly bankfull flood stage.The main channel bed has been frequently observed to be well armoured. E-2-6 ( -( Primary tributaries include Indian River,Gold Creek and Fourth of July Cr"eek.Each has formed an alluvial fan extending into the valley bottom and constricting the Susitna to a single channel. Each constriction has establ ished a hydraul ic control point that regul ates water surface profi 1es and assoc i ated hydr aul ic par a- meters at varying discharges. RM 129.5 to RM 119 River patterns through this reach are"similar to those in the pre- vious reach.The most prominent characteristic between Sherman and Curry is that the main channel prefers to flow against the west valley wa1.1 and the--e-astTloodpl ain has several side channel s and sloughs.The alluvial fan at Curry constricts the Susitna to a single channel and terminates the above described patterns.A fair correl ation exists between bankfull stage and mean annual flood through thi s reach.Compari son of 1,950 and 1980 ai rphotos reveal s occasional local changes in bankl ines and isl and morphol- ogy. The west valley wall is generally nonerodible and has occasional bedrock outcrops.The res i stant bound ar y on one si de of the mai n channel has generally forced a uniform channel configuration with a well armored perimeter.The west valley wall is relatively straight and uniform except at RM 128 and 125.5.At these loca- tions,bedrock outcrops deflect the main channel to the east side of the floodplain. RM 119 to RM 104 Through this r"each the river is predominantly a very stable, single incised channel with a few isl ands.The channel banks are well armored with cobbles and boulders,as is the bed.Several large boulders occur intermittently along the main channel and are believed to have been transported down the valley during glacial ice movement.They provide local obstruction to flow and naviga- tion,but do not have a significant impact on channel morphology. RM 104 to RM 95 At the confl uence of the Susitna,Chul itna and Tal keetna Rivers, there is a dramatic change in the Susitna from a split channel to a braided channel.Emergence from confined mountainous basins into the unconfined lowland basin has enabled the river systems to develop laterally.Ample bedload transport and a gradient de- crease also assist in establishing the braided pattern. The Chul itna River has a mean annual flow simil ar to the Susitna at Gold Creek,yet its drainage basin is about 40 percent smaller. Its glacial tributaries are much closer to the confluence than the Susitna.As it emerges from the incised canyon 20 miles upstream of the confl uence,the river transforms into a braided pattern E-2-7 t r f I l [ (" [ l l [ l J i .\ \ I ( .) with moderate vegetation growth on the intermediate gravel bars. At about a midpoint between the canyon and confluence,the Chulitna exhibits a highly braided pattern with no vegetation on intermediate gravel bars,evidence of recent lateral instability. This pattern continues beyond the confluence and giving the impression that the Susitna is tributary to the dominant Chulitna Ri ver.The spl it channel Ta lkeetna Ri ver is tri butary to the dominant braided pattern. Terraces generally bound the broad floodplain,but 'provide little control over channel morphology.General floodplain instability results from the three river system striving to balance out the combined flow and sediment regime. ........--.....----,...,.- RM 95 to 61 Downstream of the three-ri ver confl uence,the Sus i tna continues its braided pattern,with multiple channels interlaced through a sparsely vegetated floodplain. The channel network consits of the mai n channel,usually one or two subchannels and a number of minor channels.The main channel meanders irregularly through the wide gravel floodplain and inter- mittently flows against the vegetated floodplain.It has the ability to easily migrate lateralJy within the active gravel floodplain,as the main channel is simply reworking the gravel that the system previously deposited.When the main channel flows agai nst vegetated bank 1 i nes,erosi on is retarded due to the vegetation and/or bank materials that are more resistant to ero- sion.Flow in the main channel usually persists throughout the entire year. Subchannel s are usually posi ti oned near or agai nst the vegetated floodplain and are generally on the opposite side of the flood- plain from the main channel.The subchannels normally bifurcate (split)from the lJ1ain channel when it crosses over to the opposite side of the floodplain and terminate where the main channel me- anders back across the floodplain and intercepts them.The sub- channels have smaller geometric dimensions than the main channel, and their thalweg is generally about five feet higher.Their flow regime is dependent on the main channel stage and hydraulic flow controls point of bifurcation.Flow mayor may not persist throughout the year. Minor channels are relatively shallow,wide channels that traver~e the gravel floodplains and complete the interlaced braided pat- tern.These channels are very unstable and generally short-lived. The main channel is intermittently controlled laterally where it flows against terraces.Since the active floodplain is very wide, the presence of terraces has little significance except for deter- mining the general orientation of the river system.An exception is where the terraces constrict the river to a single channel at the Parks Highway bridge.Subchannels are directly dependent on E-2-8 main channel flow and sediment regime,and generally react the same.Mi nor channel s react to both of the 1arger channel s I behaviors. RM 61 to RM 42 Downstream of the Kashwitna River confluence,the Susitna River branches into multiple channels separated by islands with estab- lished vegetation.This reach of the river has be.an named Delta Islands because it resembles the distributary channel network common with large river deltas.The multiple channels are forced together by terraces just upstream of Kro~ee~~(Deshka River)• Through thi s reach,the very broad fl oodpl ain and channel network can be divided into three categories: -Western braided channels; -Eastern split channels;and -Intermediate meandering channel? The western braided channel network is considered to be the main portion of this very complex river system.Although not substan- tiated by river surveys,it appears to constitute the largest flow area and lowest thalweg elevation.The reason .for this is that the western braided channel s const itute the shortest distance between the point of bifurcation to the confluence of the Delta Is 1 and channel s.Therefore it has the steepest grad ient and highest potential energy for conveyance of water and sediment. RM 42 to RM 0 Downstream of the Delta Islands,the Susitna River gradient decreases as it approaches Cook In 1et.The ri ver tends toward a split channel configuration as it adjusts to the lower energy slope.There are short reaches where a tendency to braid emerges. Downstream of RM 20,the river branches out into delta distribu- tary channels. Terraces constrict the floodplain near the Kroto Creek confluence and at Susitna Station.Further downstream,the terraces have little or no influence on the river. The Yentna River joins the Susitna at RM 28 and is a major contri- butor of flow and sedim~nt. Tides in the Cook Inlet rise above 30 feet and therefore control the water surface profile and to some degree the sediment regime of the lower river.River elevation of 30 feet exists at about RM 20 and corresponds to where the Susitna begins to branch out into its delta channels. (b)Sloughs Sloughs are spring-fed,perched overflow channels that only convey glacial meltwater from the mainstem during median and high flow E-2-9 l [ f l [ l ! l .~. j ( \ \ ) ( .( -l periods.At intermediate and low flows,the sloughs convey clear water from small tributaries and/or upwelling groundwater.Dif- ferences between mainstem water surface elevations and the stream- bed elevation of the side sloughs are notably greater at the up- stream entrance to the slough than at the mouth of the slough. The graidents within the slough are typically greater than the adjacent mainstem.An alluvial berm separates the head of the slough from the river,whereas the water surface elevation of the mainstem generally causes a backwater effect at the mouth of the slough.The sloughs funGtion like small stream systems.Several hundred feed of channel exist in each slough conveying water independent of mainstem backwater effects. The sloughs vary in length from 2,000 -6,000 feet.Cross-se-e--..--- tions of sloughs are typically rectangular with flat bottoms.At the head of the sloughs,substrates are dominated by boulders and cobbles (8-14 inch diameter).Progressing towards the slough mouth,substrate particles reduce in size with gravels and sands predominating.Beavers frequently inhabit the sloughs.Active and abandoned dams are visible.Vegetation commonly covers the banks to the waters edge with bank cutting and slumping occurring during spring break-up flows.The importance of the sloughs as salmon spawning habitat is discussed in detail in Chapter 3. 2.3 -Susitna River Water Quality As previously described in Section 2.2,the Susitna River is charac- terized by large seasonal fluctuations in discharge.These flow varia- tions along with -the glacial origins of the river essentially control the water quality of the river. Existing water quality data have been compiled for the mainstem Susitna River from stations located at Denali,Vee Canyon,Gold Creek,Sun- shine,arid Susitna Station.In addition,data from two Susitna River tributaries,the Chulitna and Talkeetna Rivers,have also been compiled (R&M,1982b).The station locations are presented in Figure E2.1. Data were compil ed correspondi ng to three seasons:break up,summer, and winter.Breakup is usually short and extends from the time ice begins to move down river until recession of spring runoff.Summer extends from the end pf breakup until the water temperature drops to essentially O°C in the fall,and winter is the period from the end of summer to breakup.The water qual ity parameters measured and their respectively detection limits appear in Table E.2.6. The water quality was evaluated (R&M 1982b)using guidelines and cri- teria established from the following references: -ADEC,Water Quality Standards.Alaska Department of Environmental Conservation,Juneau,Alaska,1979. -EPA,Quality Criteria For Water.u.S.Environmental Protection Agency,Washington,D.C.,1976. E-2-10 I -( [ ( \ \ ( I i I ~\ -McNeely,R.N.,V.P.Neimanism abd K,Dwyer.Water Quality Source- book--A Guide to Water Quality Parameters.Environment Canada, Inland Waters Directorate,Water Quality Branch,Ottawa,Canada, 1979. -Sitting,Marshall.Handbook of Toxic and Hazardous Chemicals.Noyes Publications,Park Ridge,New Jersey,1981. -EPA,Water Quality Criteria Documents;Availability.Environmental Protection Agency,Federa 1 Reg i ster,45,79318-79379 (November 28, 1980). The guidelines or criteria used for the parameters were chosen base~DQ a priority system.Al aska Water Qual ity Standards were the first choice,followed by criteria presented ln EPA I~Quality Criteria for Water.If a criterion expressed as a specific concentratlOn was not presented in the above two references,the other cited references were used as the source. A second priority system was used for selecting the guidelines or cri- teria presented for each parameter.This was required because the v ari ous references presented above cite 1evel s of parameters that provide for the protection of identified water uses;such as (l)the propagation of fish and other aquatic organisms,(2)water supply for drinking,food preparation,industrial processes,and agriculture,and (3)water recreation.The first priority,therefore,was to present the guidelines or criteria that apply to the protection of freshwater aquatic organisms.The second priority was to present levels of para- meters that are acceptable for water supply,and the third priority was to present other guidel ines or criteria if avail able.It should be noted that water qual ity standards set criteria which limit man-induced pollution to protect identified water uses.Although the Susitna River basin i"s a pristine area,some parameters naturally exceeded their respective criterion.These parameters are presented in Table E.2.7. As noted in Table E.2.7,criteria for three parameters have been set at a level which natural waters usually do not exceed.The suggested criteri a for al urn inllT1 and bi smuth are based on human health effects. The criterion for total organic carbon (TOC)was established at 3 mg/l. Water containing less than this concentration has been observed to be relatively clean.However,streams in Alaska receiving tundra runoff commonly exceed this level.The maximum TOC concentration reported herein,20 mg/l,is likely the result of natural conditions.The criterion for manganese was establ ished to protect water suppl ies for human consumption.The criteria presented for the remaining parameters appearing in Table E.2.7 are established by law for protection of freshwater aquatic organisms.The water qual ity standards apply to man-induced alterations and constitute the degree of degradation which may not be exceeded.Because there are no industries,no significant agricultural areas,and no major cities adjacent to the Susitna, Talkeetna,and Chul itna Rivers,the measured levels of these parameters are considered to be natural conditions.Since criteria exceedance is attributed to natural conditions,1 ittle additional discussion will be given to these phenomenon.Also,these rivers support diverse E-2-11 r ! [ [ r [ [ r l l l I J \ ( ( ,\ \ ( popul ations of fish and other aquatic 1 ife.Consequently,it is con- cluded that the parameters exceeding their .criteria probably do not 'have significant adverse effects on aquatic organisms. In the following di'scussion,parameters measured during breakup will generally not be discussed since data normally indicate a transi tion period between the winter and summer extremes and the data itself is usually limited.Levels of.water quality parameters discussed in the following section are reported by R&M (1982b),unless otherwise noted. (a)Physical Parameters (i)Water Temperature -Mainstem In general,during winter,the entire mainstem Susitna River is at'or near DoC.However,there are a number of small discontinuous areas with groundwater inflow of near 2°C.As spr ing breakup occurs the water temperature begins to rise,generally warming with distance down stream. In summer,glacial melt is near DoC as it leaves the gl acier,but as it flows across the wide gravel flood- plain below the glaciers the water begins to warm.As the water winds its way downstream to the proposed Watana damsite it can reach temperatures as high as 14°C. Further downstream there is generally some additional warming but,temperatures may be cooler at some locations due to the effect of tributary inflow.In August, temperatures begin to drop,reaching DoC in 1 ate September or October. The seasonal temperature variation for the Susitna River at Denal i and Vee Canyon during 1980 and for Denal i and Watana during 1981 are displayed in Figures E.2.26 and E.2.27.Weekly averages for Watana in 1981 are shown in Fi gure E.2.28.The shaded area ind icates the range of temper atures measured on a mean d ail y bas is.The temperature variations for eight summer days at Denal i, Vee Canyon and Susitna Station are presented in Figure E.2.29.The recorded variation in water temperatures at the seven USGS gaging stations is displayed in Figure E.2.30. Additional data on water temperature are available in the annua 1 reports of U.S.G.S.Water Resources 0 ata for Alaska,the Al aska Department of Fl sh and Game (ADF&G) Susitna Hydroelectric Project data reports (Aquatic Habitat and Instream Flow Project -1981,and Aquatic Studles Program -1982),and ln Water Quality Data - 1981b,1981c,R&M Consultants. E-2-12 ( ( f -Sloughs The sloughs downstream of Devil Canyon have a temperature regime that differs form the mainstem.During the winter of 1982 i ntergravel and surface water temperatures were measured in sloughs 8A,9,11,19,20 and 21,the loca- tions of which are illustrated in Figure E.2.31.These measurements indicated that intergravel temperatures were rel atively constiint through February and March at each location but exhlbited some variabil ity from one location to another.At most stations intergravel temperatures were within the 2-3°C range.Slough surface temperatures showed more variability at each location and were generally lower than intergravel temperatures during February and March (Trihey,1982a). During spring and summer,when flow at the head of the slough is cut off,slough temperatures tend to differ from mainstem temperatures.During periods of high flows,when the head end is overtopped,slough water temperatures correspond more closely to mainstem tempera- tures.Figure E.2.32 compares weekly diel surface water temperature variations during September,1981 in Slough 21 with the mainstem Susitna River at Portage Creek (ADF&G,1982).The slough temperatures show a marked diurnal variation caused by increased solar warming of the shallow water during the day and subsequent long wave back radiation at night.Mainstem water temperatures are more constant because of the buffering and mixing capabil ity of the river. -Tributaries The tributaries to the Susitna River generally exhibit cooler water temperatures than does the mainstem.Con- tinuous water temperatures have been monitored by the USGS in the Chulitna and Talkeetna Rivers near Talkeetna, and al so by ADF&G in those two rivers as well as in Portage,Tsusena,Watana,Kosi na,and Goose Creeks,and in Indian and the Oshetna River. The 1982 mean daily temperature records for Indian River and Portage Creek are compared in Figure E.2.33.Portage Creek was consistently cooler than Indian River by 0.1 to 1.9°C.The fl atter terrain in the lower reaches of the Indian River valley is apparently more conducive to solar and connective heating than the steep-walled canyon of Portage Creek.Figure E.2.33 also presents water temper- ature data from the mainstem Susitna for the same period, showing the consistently warmer temperatures in the main- stem. E-2-13 I r [ f I r r r ( [ l [ l l L l There are noticeable diurnal flucutations in the open- water tributary temperatures,though not as extreme as in the sloughs.Daily variation of up to 6.5°C (from 3.0 to 9.5°C)was observed at Portage Creek in 1982 (June 14). The major tributaries joining the Susitna at Talkeetna show uniform variation in temperatures from the mainstem .. Compared to the Talkeetna fishwheel site on the Susitna, the Talkeetna River temperature is I-3°C cooler on a daily average basis.The Chulitna River,being closer to its glacial headwaters,is from 0 ~o 2°C cooler than the Talkeetna river,and has less during fluctuations. Winter stream temperatures are expected to be very close to O°C,as all the tributaries do freeze up.Groundwater inflow at some locations may create local conditions above freezing,but the overall temperature regime would be affected by.the extreme cold in the environment. (ii)Ice -Freeze-up Air temperatures in the Susitna basin increase from the headwaters to the lower reaches.Whil e the temperature gradient is partially due to the two -degree latitudinal span of the river,it is,for the most part due to the 3,300-foot difference in el ev at i on between the lower and upper basins,and the climate-moderating effect of Cook Inlet on the lower river reaches.The gradient results in a period (late October -early Novenber)in which the air temperatures in the lower bas.in are above freezing while sUbfreezing in the upper basin.The location of freezing air temperatures moves in a downstream direction as winter progresses (R&M,1982c). Frazil ice forms in the upper segment of the river first, due to the initial cold temperatures of glacial melt and the earlier cold air temperatures.Additional frazil ice is generated in the fast-flowing rapids between Vee Canyon and Devil Canyon.The frazil ice generation nor- mally continues for a period of 3-5 weeks before a solid ice cover forms in the lower river,often a result of frazil-ice pans and floes jamming in suitable reaches. Once frazi 1 ice jams form,the ice cover progresses up- stream,often raising water levels by 2 to 4 feet.Bor- der ice formation along the river banks also serves to restrict the channel. E-2-14 ( -j .l The upper Susitna River is the primary contributor of ice to the river system below Talkeetna,contributing 75-85 percent of the ice load in the Susitna-Chulitna-Talkeetna Rivers.Ice formation on the Chulitna and Talkeetna Rivers normally commences several weeks after freeze-up on the middle and upper Susitna River. -Winter Ice Conditions Once the solid ice cover forms,open leads still occur in areas of high-velocity water or groundwater upwell ing. These leads shrink during cold weather and are the last areas int,he main channel to be completely covered by ice.Ice thickness increases throughout the winter.The ice cover averages over 4 feet thick by breakup,but thicknesses of over 10 feet have been recorded near Vee Canyon. Some of the side-channels and sloughs above Talkeetna do not form an ice cover dur i ng wi nter due to groundwater exfiltration.Winter groundwater temperatures generally varying between 2°C to 4°C contribute enough heat to prevent the ice cover from forming (Trihey 1982a).These areas are often salmonid egg incubation areas. Breakup The onset of warmer air temperatures occurs in the lower basin several weeks earlier than in the upper basin,due to the temperature grad ient prev ious 1y noted.The low- elevation snowpack melts first,causing river discharge to increase.The rising water level puts pressure on the ice,causing fractures to develop in the ice cover.The severity of breakup is dependent on the snowmelt rate,on the depth of the snowpack and the amount of rainfall,if it occurs.Alight snowpack and warm spring temperatures result in a gradual increase in river discharge.Strong forces on the ice cover do not occur to initiate ice movement resulting in a mild breakup,as occurred in 1981 (R&M,1981d).Conversely,a heavy snowpack and cool air temperatures into late spring,followed by a sudden increase in air temperatures may result in a rapid rise in water level.The rapid water level increase initiates ice movement and this movement coupled with ice left in a strong condition from the cooler temperatures leads to nLATIerous and possibly severe ice jerns which may result in flooding and erosion,as occurred in 1982 (R&M,1982f). The flooding results in high flows through numerous side- channels in the reach above Talkeetna.The flooding and erosion during breakup are bel ieved to be the primary factors influencing river morphology in the reach between Dev il Canyon and Ta 1keetn a (R&M,1982a).. E-2-15 [ r I I l r l [ l. \ \ -I ( ( (iii)Suspended Sediments The Susitna River and many 'of its major tributaries are glacial rivers which experience extreme fluctuations in suspended sediment concentrations as the result of both glacial melt and runoff from rainfall or snowmelt.Beginn- ing with spring breakup,suspended sediment concentrations beg in to ri se from their near zero wi nter 1evel s.Our i ng summer,val ues as hi gh as 5700 mg/l have been recorded at Denali,the gaging station nearest the glacially-fed head-' waters.Before entering the areas of the proposed reser- voirs,concentrations decrease due to the inflow from several clear water tributaries.Maximum summer concentra- tions of 2600 mg/l have been observed at Gold Creek.Below Talkeetna,concentrations increase due to the contribution of the sediment-laden Chulitna River which has 28 percent of its drainage area covered by year round ice.Max imum values of 3000 mg/l have been recorded at the Susitna Sta- tion gage.A more extensive summary of suspended sediment concentrations is presented in Figure E.2.34. Suspended sediment discharge has been shown to increase with discharge tR&M,1982d).This relationship for various upper Susitna River stations is illustrated in Figure E.2.35. Estimates of the average annual suspended sediment load for three locations on the upper Susitna River are provided in the following table (R&M,1982d). The suspended sediment load entering the proposed Watana Reservoir from the Susitna River is assumed to be that at the gaging site for the Susitna River near Cantwell,or 6,898,000 tons/year (R&M,1982d). A suspended sediment size analysis for upper Susitna River stations is presented in Figure E.2.36.The analysis indicates that between 20 and 25 percent of the suspended sediment is less than 4 microns (.004 millimeters)in diameter. ( ( i i \ -\ I ( Gaging Station Susitna River at Denali Susitna River near Cantwell Susitna River at Gold Creek Average Annual Suspended Sediment Load (tons/year) 2,965,000 6,898,000 7,731,000 E-2-16 ( \ \ \ i i ( 1 I ( (iv)Turbidity -Mainstem The Susitna River is typically clear during the winter months with values at or very near zero.Turbidity increases as snownel t and breakup commence.The peak turbidity values occur during summer when glacial input is greatest. Limited turbidity data are available for the headwaters of the Susitna River.However,measurements-up to 350 Nepholometer Turbidity units (NTU)have been recorded at Denali.Turbidity tends to decrease in the vicinity of the project areas due to clearwater inflow,although high values still exist.At the mouth of the Chulitna River near Talkeetna,values of over 1900 NTU have been observed.In contrast,max imum observed val ues on the Talkeetna River,with its minimal glacial input,were 270 NTU.Results of data collection are summarized in Figure E.2.37 (R&M,1982e).Data collected at various sites in 1982 are tabulated in Table E.2.8. Figure E.2.38 shows the direct relationship between sus- pended sediment concentation and turbidity as measured on the Susitna River at Cantwell,Gold Creek,and Chase (Peratrovich,Nottingham and Drage,1982a).However, suspended sediment concentrations can vary significantly at similar flow ranges,as the glaciers contribute highly variable amounts of sediment (R&M,1982d)\ -Sloughs Turbidity values for selected sloughs were collected by ADF&G during the summer of 1981.The turbidity in the sloughs was less than the turbidity jn the mainstem except when upstream ends were overto.pped at which time the turbidities usually mirror~-mainstem level s (ADF&G, 1982).Even with overtoppir;1g,some sloughs maintained lower turbidity due to grounqwater or tributary inflow. \ (v)Vertical Illumination Vertical illumination through the water column varies d irectl y with turb id ity and suspended sedi~nt concentra- tion and hence follows the same temporal'",and spatial patterns.Although no quantitive assessment wa~conducted, summer vertical illumination is generally a fe'w,,-inches. During winter months,the river bottom can be seen lQ areas without-ice cover,as the river is exceptionally 'clear. Vertical illumination under an ice cover is inhibited, especially if the ice is not clear and if a snow cover exists over the ice. E-2-17 - [ [ I l [ f l [ l 1 l I ( ,~ .1 I i ( ( I· I j i ! ( ,1 1 ( I (vi)Total Dissolved Solids (TDS) Di'ssolved solids concentratons are higher,and ·exhibit a wider range during the winter low-flow periods t~an during the summer period.Data at Denali range from 110-270 mg/l in the wi nter and from 40-170 mg/l i·n the summer.Pro- g~essing downstream on the Susitna River basin,TDS concentrations are generally lower. Gold Creek TDS winter values are 100-190 mg/l,while summer concentrations are 50-140 mg/l.Measurements at Susitria Station,range from 100-140 mg/l during winter and between 55 and 80 mg/l in the summer."Figure E.2.39 provides a graphic representation of the data collected. (vii)Specific Conductance (Conductivity) Susitna River conductivity values are high during winter low-flow periods and low during the summer.In the up- stream reaches where glacial input is most significant, conductivity is generally higher.At Denali,values range from 190-510 umhos/cm in the winter and from 120-205 umhos/cm in the summer. Below Devil Canyon,conductivity values range from 160-300 umhos in the winter and from 60-230 umhos/cm in the summer. The Chul itna and Talkeetna Rivers have sl ighly lower con- ductivity values,but are in the same tange as in the Susitna River. Figure E.2.40 graphically provides the maximum,minimum and the mean values as well as the mmber of conductivity ob- servations for the seven gaging stations. (viii)Significant ions Concentrations of the significant ions are generally low to moderate,with summer concentr~tions lower than winter con- centrat ions.The ranges of concentrat ions recorded up- stream of the project at Denal i and Vee Canyon and down- stream of the project at Gold Creek,Sunshine and Susitna Station are 1 isted in Table E.2.9.The ranges of ion con- centrations at each monitoring station are presented in Figures E.2.41 to E.2.46. (ix)..e!! Average pH values tend to be slightly alkaline with values typically ranging between 7 and 8.A wider range is gener- ally exhibited during the spring breakup and summer months with values occasionally dropping below 7.This phenomenon is common in Al askan streams and is attributable to the acidic tundra runoff. E-2-18 -\ I I I ( I \ ! j j I j I j ( I Winter pH ranges at the Gold.Creek station are between 7.0 and 8.1 while the range of summer values is 6.6 to 8.1. Figure E.2.47 displays the pH information 'for the seven stations of record. (x)Total Hardness Waters of the Susitna River are moderately hard to hard in the winter,and soft to moderately hard during breakup and summer.In addition,there is a general trend toward softer water in the downstream direction. Tota 1 hardness,measured as cal c iurn magnes i urn hardness and reported in terms of CaC03,ranges between 60-120 mg/l at Gold Creek during winter,and betwen 30-105 mg/l in the summer.At Susitna Station,winter values are 70-95 mg/l while summer values range from 45 to 60 mg/l. Figure E.2.48 presents more detailed total hardness infor- mat ion. (xi)Total Alkalinity Total Alkal inity concentrations with bicarbonate typically being the only form of alkal inity present,exhibit moderate to high levels and display a much larger range during winter than the low to moderate summer values.In addition,upstream concentrations are generally larger than downstream values. Winter values.at Gold Creek range between 45 and 145 mg/l, while .summer values are in the range of 25 to 85 mg/l.In the lower river at Susitna Station,winter 'concentrations are between 60-75 mg/l and summer 1 evel s are in the range of 40-60 mg/l. Figure E.2.49 displays a more detailed description of total alkal inity concentrations. (xii)True Color True color,measured in platinum cobalt units,displays a wi der range dur ing summer than wi nter.Th is phenomenon is attributable to organic acids (especially tannin)charac- teristically present in the summer tundra runoff. Color levels at Gold Creek vary between 0 and 10 color units during winter and 0 to 40 units in the summer.It is not uncommon for color levels in Al aska to be as high as 100 un its for streams receiv ing tundra runoff,i.e.,the maximum recorded value at the Sunshine gauge. Figure E.2.50 displays the data collected. E-2-19 l r \ I r l l r [ [ r l l ! l I ~ I ~I I • \ -I I I ) I ,I ! i i (xii i)Met a 1s The concentrations of'many metals monitored in the river were low or within the range characteristic of natural waters.Eight parameters antimony (sb),boron (8),gold (Au),dissolved molybdentm (M),platinum (Pt),tin (Sn), vanadium (V)and ziJ:'conium (Zr)were below detectable limits.However,the concentrations of some trace elements exceeded water qual ity guidP.l ines for the protection of freshwater organisms.(Table E.2.4).These concentrations are the result of natural processes,since with the exception of some placer mining activities,there are no man-induced sources of these el ements in the Susitna Ri ver basin.Metals which have exceeded these limites include allJ11inum (Al),copper (Cu),iron (Fe),lead (Pb),manganese (Mn),mercury (Hg),nickel (Ni)and zinc (Zn). Figures E.2.51 through E.2.68 summarize the heavy metal data that were collected. (b)Dissolved Gases .(i)Dissolved Oxygen Dissolved oxygen (D.O.)concentrations generally remain quite high throughout the drainage basin.Winter values average near 13 mg/l while summer concentrations average between 11 and 12 mg/l.These concentrations equate to dissolved oxygen saturation levels generally exceeding 80 percent,although summer val ues average near 100 percent. Winter saturation levels decline slightly from summer levels,averaging near 97 percent at Gold Creek and 80 percent at Susitna Station. . Figures E.2.69 and E.2.70 contain additional dissolved oxygen.data. (ii)Nitrogen Supersaturation Limited sampling for dissolved gas concentrations,namely nitrogen and oxygen,was performed during the·1981 field season.However,continuous monitoring equipment was installed in the vicinity of Devil Canyon for approximately two months (8 August -10 October)during 1982.This data is not available at this time but will be included when it is available.The 1981 data indicated that supersaturation existed above Devil Canyon as well as below ranging from 105.3 percent to 116.7 percent,respectively. Al aska water qual ity statutes call for a maximum dissolved gas concentration of no higher than 110 percent. E-2-20 I l ~ =1 \ I I ( j I I j j I ! 1 I ( ,\ (c)Nutrients Nutrient concentrations,specifically nitrate nitrogen and ortho- phosphate,exist in low to moderate concentration throughout the Susitna River.Nitrate concentrations are less than 1.0 mg/1 along the Susitna,although Talkeetna River values have reached 2.5 mg/l.Gold Creek nit.rate concentrations vary from below detectable limits to 0.4 mg/l. Biologically available orthophosphates are generally less than 0.2 mg/1 throughout the drainage bas in.Gold Creek orthophosphate values vary from below detectable limits to 0.1 mg/l.most values at Vee Canyon are also in this range.This data is depicted in Figures E.2.71 and E.2.72. Studies of glacially influenced lakes in Alaska (Koenings and Kyle,1982)and Canada (St.John et al.,1976)indicate that over 50 percent of the total phosphorus concentration in the 1 akes studied was biologically inactive.This was attributed to the fact that the greatest percentage of the 1 akes I total phosphorus occurred in the particulate form.Consequently,phosphorus available in the dissolved form is much less than recorded values. This is discussed i~more detail by Peterson and Nichols,(1982). Of the maj or nutri ents--carbon,s il ic a,nitrogen and phosphorus, the limiting nuturient in the Susitna River is phosphorus (Peterson and Nichols 1982). (d)Other Parameters (i)Chlorophyll-a Chlorophyll-a as a measure of algal biomass is quite low due to the poor light transmissivity of the glacial waters. The only chlorophyll-a data available for the Susitna River were collected at the Susitna Station gage.Values up to 1.2 mg/m 3 for chloroph.yll-a (periphyton.uncorrected)have been recorded.However,us i ng the chromospectropi c technique,values ranged from 0.004 to 0.029 mg/m 3 for three samples in 1976 and 1977.All recorded values from 1978 through 1980 were 1ess than detectab 1e 1 imits when analyzed using the chromographic fluorometer technique. No data on chlorophyll-a are available for the upper basin. However,with the very high suspended sed iment concentr a- tions and turbidity values,it is expected that chloro- phyll-a values are very low. (ii)Bacteria No data are available for bacteria in the upper river basin.However,because of the glacial origins of the river and the absence of domestic,agricultural,and industrial developnent in the watershed,bacteria levels are expected to be quite low. E-2-21 ! r [ [ ( [ l. l. l t 1 ~. Only 1 imited data on bacterial indicators are avail able from the lower river basin,namely for the Talkeetna River since 1972,and from the Susitna River at'SusitnaStation since 1975.Indicator organisms monitored include total coliforms,fecal coliforms,and fecal streptococci. Total coliform counts were generally quite low,with all three samples at Susitna Station and 70 percent of the samples on the Talkeetna River registering less than 20 colonies per 100 ml.Occasional high values have been recorded during summer months,with a ,max imum val ue of 130 colonies per 100 ml. Fecal coliforms were also low,usually registering .less than 20 colonies per 100 ml.The maximum recorded summer values were 92 and 91 colonies per 100 ml in the Talkeetna and Susitna Rivers,respectively. Fecal streptococci data also display the same.pattern;low values in winter months,with occasional high counts during the summer months. All recorded values are believed to reflect natural varia- tion within the river,as there are no significant human influences throughout the Susitna River Basin that would affect bacterial counts. (iii)Others Concentrations of organic pesticides and herbicides, uranilJT1,and gross alpha radioactivity were either less than their respective detec,tion limits or were below levels considered to be potentially harmful.Since no significant sources of these parameters are known to ex ist in the drainage basin,no further discussions will be pursued. (e)Water Quality Summary The Susitna River is a fast flowing,cold-water glacial stream of the calcium bicarbonate type containing soft to moderately hard water during breakup and summer,and moderately hard water in the winter.Nutrient concentrations,namely nitrate and orthophos- phate,exist in low-to-moderate concentrations.Dissolved oxygen concentrations typically remain high,averaging about 12 mg/1 dur- ing the summer and 13 mg/1 during winter.Percentage saturation of dissolved oxygen generally exceeds 80 percent and averages near 100 percent .in the summer.Winter saturation levels decline slightly from the summer levels.Typically,pH values range between 7 and 8 and exhibit a wider range in the summer compared to the winter.During summer,pH occasionally drops below 7, which is attributed to organic acids in the tundra runoff.True color,al so resulting from tundra runoff,displ ays a wider range E-2-22 I I ~ ~ I -I I I ! I I j I I ( I I I dur i ng summer than wi nter.Values have been measured as hi gh as 40 color units in the vicinity of the damsites.Temperature remains at or near O°C during winter,and the summer maximum is 14°C.Alkalinity concentrations,with bicarbonate as the dominant ani on,are low to moderate duri ng summer and moderate to hi gh during winter.The buffering capacity of the river is relatively low on occasion.. The concentrations of many trace elements monitored in the river were low or within the range characteristics of natural waters. However,the concentrations of some trace elements exceeded water .quality guidelines for the protection of freshwater aquatic organ- isms.These concentrat ions are the resul t of natura 1 processes because with the exception of some placer mining activities there are no man-induced sources of these elements in the Susitna River Basin. Concentrations of organic pesticides and herbicides,uranium,and gross al pha radioacti vity were either less than their respecti ve detection limits or were below levels considered to be potentially harmful to acquatic organisms. 2.4 -Baseline Ground Water Conditions (a)Description of Water Table and Artesian Conditions The landscape of the upper basin consists of relatively barren bedrock mountains with exposed bedrock cliffs in canyons and along streams,and areas of unconsolidated sediments (outwash,till, alluvium)with low relief particularly in the valleys.The arctic climate has retarded development of topsoil.Unconfined aquifers exist in the unconsolidated sediments,although there is no water table data in these areas except in the relict channel at Watana and the south abutment at Devi 1 Canyon.Wi nter low flows in the Susitna Ri ver and its major tri butaries are fed primarily from ground water storage in unconfi ned aqui fers.The bedrock withi n the basin tomprises crystalline and metamorphic rocks.No significant bedrock aquifers have been identified or are anticipated. Below Talkeetna,the broad plain between the Talkeetna Mountains and the Alaska Range generally has higher ground water yields, with the unconfined aquifers immediately adjacent to the Susitna River having the highest yields (Freethey and Scully,1980). (b)Hydraulic Connection of Ground Water and Surface Water Much of the ground water in the system is stored in unconfi ned aquifers in the valley bottoms and in alluvial fans along the slopes.Consequently,there is a direct connection between the ground water and surface water.Confined aquifers may exist within some of the unconsolidated sediments,but no data are available as to their extent. E-2-23 r l J~ [ r { l I t l I I ~ I l I I -I ) I I I I I I I, I \ I I I (c)Locations of Springs,Wells,and Artesian Flows Due to the wilderness character of the basin,there is no data on the location of springs,wells,and artesian flows.However, winter aufeis buildups have been observed between Vee Canyon and Fog Creek,indicating the presence of ground water discharges. Ground water is the main source of flow during winter months,when precipitation falls as snow and there is no glacial melt.It is believed '~hat much of this water comes from unconfined aquifers (Freethey ;nd Scully,1980). (d)Hydraulic Connection.of Mainstem and Slough~ Ground water studies in respresentative sloughs downstream of Devil Canyon indicate that there is a hydraulic connection between the mainstem Susitna River and the sloughs.These sloughs are used by salmonid species for spawning and hence are important to the fisheries.Ground water observation wells indicate that the upwelling in the sloughs,which is necessary for egg incubation, is caused by ground water flow from the upl ands and from the \. mainstem Susitna.The higher permeab'i1ity of the valley bottom ( sediments (sand-gravel-cobble-alluvium)compared with the till \ mantle and bedrock of the valley sides indicates that the mainstem \ Susitna River is the major source of ground water inflow in the \ sloughs.Preliminary estimates of the travel time of the ground )1 water from the mainstem to the sloughs indicate a time on the order of six months. 2.5 -Existing Lakes,Reservoirs,and Streams (a)Lakes and Reservoirs There are no existing reservoirs on the Susitna River or on any of the tributaries flowing into either Watana or Devil Canyon Reser- voirs.No 1akes downstream of the reservoirs are expected to realize any impact from project construction,impoundment,or operation.A few lakes at and upstream of the damsites,however, will be affected by the project. The annual maximum pool elevation of 2190 feet in the Watana Reservoir will inundate several lakes,none of which are named on USGS topographic quadrangle maps.Most of these are small tundra lakes and are located along the Susitna between RM 191 and RM 197 near the mouth of Watana Creek.There are 27 1akes 1ess than 5 acres in surface area,one between 5 and 10 acres,and one relatively large one of 63 acres,all on the north side of the river.In addition,a small lake (less than 5 acres)lies on the south shore of the Susitna at RM 195.5 and another of about 10 acres in area lies on the north side of the river at RM 204.Most of these lakes appear to be simply perched,but five of them are connected by small streams to Watana Creek or to the Susitna River itself. E-2-24 I j 1 =1 I I I I I I 1 I I j I I I I I A small lake (2.5 acres)lies on the south abutment near the Devil Canyon dansite,at RM 151.3,and at about elevation 1400 feet.No other lakes exist within the proposed Devil Canyon Reservoir. (b)Streams I Several streams in each reservoir will be completely or partially inundated by the raised water levels during project filling and operation.The streams appearing on the 1:63,360 sclae USGS quadrangle maps are 1 isted by reservoir in Tables E.2.1O and E.2.11.·Listed in the tables are map name of each stream,river mile locations of the mouth,existing elevation of the stream mouths,the average stream gradient,the number of miles of stream to be inundated.Annual maximum reservoir elevations of 2190 feet and 1455 feet were used for these determination~for the Watana and Devil Canyon pools,respectively. There is a small slough with two small ponds on it at RM 212,four miles upstream from the mouth of Jay Creek.This slough,which is at approximately elevation 1750,will be completely inundated by the Watana Reservoir.Similarly,there are five sloughs (at RM 180.1,174.0,173.4,172.1,and 169.5)which will be totally inun- dated by the Devil Canyon Reservoir. As i de from the streams to be inund ated by the two proj ect impound- ments,there are several tributaries downstream of the project which may be affected by changes in the Susitna River flow regime. Since post-project summer stages in the Susitna will be several feet lower than pre-project levels,some of the creeks may either degrade to the lower elevation or remain perched above the river. Analysis was done on 19 streams between Devil Canyon and Talkeenta which were determined to be important for fishery reasons or for maintenance of.existing crossings by the Alaska Railroad (R&M 1982).These streams are listed in Table E.2.12,with their river mile locations and reason for concern. 2.6 -Existing Instream Flow Uses Instrean flow uses are uses made of water in the stream channel as opposed to withdrawing water from the stream for use.Instream flow used include hydroelectric power generation;commercial or recreational navigation;waste load assimilation;downstream water rights;water requirements for riparian vegetation,fish and wildlife habitat;and recr.eat ion;freshwater recruitment to estuaries;and water requi red to maintain desirable characteristics of the river itself.Existing instream flow uses on the Susitna River include all these uses except hydroelectric power operation. (a)Downstream Water Rights The 18 different areas in the Susitna River Basin investigated for water rights are shown in Figure E.2.73 (Dwight,1981).Table E.2.13 indicates the total amount of surface water and ground water appropriated within each area.The only significant uses of surface water in the Susitna River Basin occur in the headwaters of the Kahiltna and Willow Creek township grids where placer E-2-25 r [ r I l l l (b) I I ~ I .1 mlnlng operations take place on a seasonal basis.No surface water withdrawals from the Susitna River are on file with the Alaska Department of Natural Resources (DNR).Ground water appro- priations on file with DNR for the mainstem Susitna River corridor are min imal,both in terms of nunber of users and the amount of water being withdrawn. An analysis of topographic maps and overlays showing the specific location of each recorded appropriation within the mainstem Susitna River corridor indicated that neither the surface water diversions from small tributaries nor th.e groundwater withdrawal s from shallow wells will be adversely affected by the proposed Susitna Hydroelectric project (DwigHt 1981).Hence,no further discussion on water rights is presented. Fishery Resources The Susitna River supports popul ations of both anadromous and resident fish.Important commercial,recreational,and subsis- tence species include pink,chum,coho,sockeye and chinook salmon,eulachon,rainbow trout,and Arctic grayling.Instream flows presently provide for fish passage,spawning,incubation, rearing,overwintering,and outmigration.These activities are correl ated to the natural hydrograph.Salmon spawn on the receeding 1 imb of the hydrograph,the eggs incuQate through the low-flow period and fry emergence occurs on the ascending limb of the hydrograph.Rainbow trout and grayl ing spawn during the high flows of the breakup period with embryo development occurring during the early summer.Alteration of the natural flow regime during reservoir filling and project operation will likely result in both detrimental and beneficial effects on the fishery resources-of the Susitna River (see Chapter 3). (c)Navigation and Transportation Navigation and transportation use of the Susitna River presently consists of boating for recreation sport fishing,hunting,and some transportation of goods.The reach from the headwaters of the Susitna River to the Devil Canyon damsite has experienced limited use,primarily related to hunters and fishers'access to the Tyone River area after 1aunching at the DenaJ i Highway.Some recreational kayaking,canoeing,and rafting has also taken place downstream from the Denali Highway Bridge,generally stopping near Stephan Lake or some other points above the rapids at Devil Creek. Steep rapids near Dev il Creek and at the Dev il Canyon damsite are barriers to most navigation,though a very small number of kay- akers have successfully traveled through the Devil Canyon rapids in recent years.There have been several unsuccessful attempts to penetrate the canyon,both going upstream and downstream,in a powerboat and in kayaks. E-2-26 I , I I . J Below Devil Canyon,the river is used for access to salmon fishing at several sites as far upstream as Portage Creek.This is under- taken by private boat-owners and by anglers using commercial boat operators.In either case,most of the boat-launching is done at Talkeetna.Commercial operators from Talkeetna also cater to sightseeing tourists,who travel upriver to view the diversified terrain and wildlife.There is recreational boating in this reach,frequently by kayakers or canoeists floating downriver to Talkeetna from the railroad access point at Gold Creek. Access to the Susitna downstream of Talkeetna is obtai ned at Talkeetna,from a boat-launching site ·at Susitna Landing near Kashwitna,at several of the minor tributaries between Talkeetna and Cook Inlet,and from Cook Inlet.Other primary tributaries accessible by road are Willow Creek,Sheep Creek,and Montana Creek.Virtually this entire reach of the Susitna is navigable under most flow conditions although abundant floating debris during extreme high water and occasional shallow areas during low water make navigation treacherous at times. Identified restrictions of open-\'later navigation over the full length of the river are tabulated in Table E.2.14. Under the existing flow regime,the ice on the river breaks up and the river becomes ice-free for navigation in mid to late May. Flows typically remain high from that time thr·ough the summer until later September or early October,when freezing begins.The onset of river freezing causes discharge of significant frazil ice for several days in an initial surge,which hinders boat opera- tion,but this is often followed by a frazil-free period of 1 to 2 weeks when navigation is again feasible.The next sequence of frazil generation generally leads into continuous freezing of the river,-prohibiting open-water navigation until after the next spri ng breakup. The Susitna is used by several modes of non-boat transportation at various times of the year.Fixed-wing aircraft on floats make use of the river for landings and take-offs during the open water sea- son.These are primarily at locations in the lower 50 miles above the mouth.Floatplane access also occurs on occasion within the middle and upper Susitna reaches. After the river ice cover has solidly formed in the fall,the river is used extensively for transportation access by ground methods in several areas.Snow machines and dogsleds are commonly used below Talkeetna;the Iditarod Trail crosses the river near the Yentna River confluence and is used for an annual dogsled race in February.Occasional crossings are also made by automobiles and ski,primarily near Talkeetna and near the mouth. (d)Recreation Information 6n the recreation uses on the Susitna River are pre- sented in Chapter 7. E-2-27 l [ r r l ( r t l I l t l I , I J I I,,i I'II ) ,\ J (e)Riparian Vegetation and Wildlife Habitat .Wetlands cover large portions of the Susitna River Basin,includ- ing riparian zones along the mainstem Susitna,sloughs,arid tribu- tary streams.Wetlands are biologically important because they generally support a greater diversity of wildlife species per unit area than most other habitat types in Al aska.In addition,ripar- ian wetlands provide winter browse for moose and,during severe winters,can be a critical survival factor for this species.They al so hel p to maintain water qual ity throughout regional water- sheds.Further information on riparian wetlands and wildlife hab- itat can be found in Chapter 3. (f)Waste Assimilative Capacity Review of the Alaska Department of Environmental Conservation doc- ument entitled IIInventory of Water Pollution Sources and Manage- ment Actions,Maps and Tables ll (1978)indicates that the primary sources of pollution'to the Susitna River watershed are placer mining operations.Approximately 350 sites were identified although many of these cl aims are inactive.As the result of these operations,1arge amounts of suspended sediments are intro- duced into the watershed.However,nQ biochemical oxygen demand (BOD)is pl aced on the system and therefore,the waste assimil a- tive capacity remains unaffected by these mining activities. As for BOD discharges in the watershed,the inventory did identify one municipal discharge in Talkeetna,two industrial wastewater discharges at Curry and Talkeetna,and three solid waste dumps at Talkeetna,Sunshine,and Peters Creek.No volumes are available for these pollution sources. During personal communication (1982)with Joe LeBe.au of the Ala,ska Department of Environmental Conservation (DEC)it was noted that no new wastewater disc harges of any s ignifi cance have developed since the 1978 report.Further,he noted that the sources that do exist are believed to be insignificant. Mr.Robert Fl int of the DEC indicated that,in the absence of reg- ul ated flows and significant wastewater discharges,the DEC has not established minimum flow requirements necessary for the main- tenance of the waste assimilative capacity of the river (personal communication,1982). I I (g)Freshwater Recruitment to Estuaries The Susitna River is the chief contributor of freshwater to Cook In 1et and as such has a maj or infl uence on the sal in ity of Cook Inlet.The high summer freshwater flows cause a reduction in Cook,Inlet sal inities.During winter flows the reduced flows per- mit the more sal ine water to move up Cook Inl et from the ocean. Using a computer model for the Cook Inlet,Resource Management E-2-28 ~ J 1 } I I I I i Associates (RMA,1982)predicted a seasonal salinity variation near the mouth of the Susitna River of 15 parts per thousand (ppt).In the central part of the inlet,sal inity varies seasonally by about 5 ppt. Salinity measurements were taken at the mouth of the Susitna River in August 1982 to determine if and to what extent sal twater in- truded upstream.No saltwater 'intrusion was detected.Flow was approximately 100,000 cfs at Susitna Station at the time the meas- urements were made.Additional sal inity measurements will be made during the 1982-83 winter season to determine if salt water"pene- tration occurs upstream of the mouth of the river during low flow periods. 2.7 -Access Plan (a)Flows The streams crossed by the access road are typi c al of the sub- arctic,snow-dominated flow regime,in which a snownelt flood in spring is followed by generally low flow through the summer, punctuated by periodic rainstorm floods.During October-April, precipitation falls as snow and remains on the ground.The annual low flow occurs during this period,and is almost completely base flow. Streamflow records for these small streams are sparse.Conse- quently,regression equations developed by the U.S.Geological Survey (Freethey and Scully,1980)have been utilized to estimate the 30-day low flows for recurrence intervals of '2,10,and 20 years,and the peak flows far recurrence interval s of 2,10,25, and 50 years.These flows are tabulated in Table E.2.15 for three segments of the access route:(1)Denal i Highway to Watana Camp; (2)Watana Camp to Devil Canyon Camp;and (3)Devil Canyon to Gold Creek.Only named streams are presented. (b)Water Quality At present very 1 ittle water qual ity data is avail able for the water resources in the vicinity of the proposed access routes. 2.8 -Transmission Corridor The transmission corridor consists of four segments:the Anchorage- Willow 1 ine,the Fairbanks-Healy 1 ine,the Willow-Healy Intertie,and the Gold Creek-Watana 1 ine.The first two (from Anchorage and Fair- banks)have existing facilities,but they will be upgraded before Watana comes on 1 ine.The intertie is currently being constructed under an.other contr act.The 1 i ne between the d am and the intert ie has yet to be designed,sited,or constructed. E-2-29 f f I I i r- ( I t [ ( , L J J J (a)Flows Numerous waterbodies in each of the four sections will be crossed by the transmission 1 ine.Most of these are small creeks in remote areas of the region,but each segment has some major cros- sings.Data are very 1 imited on the small streams,both with respect to water quantity and water qual ity.Most of the major crossings,however,have been gaged at some point along their length by the USGS.Major stream crossings are identified below. Pertinent gage records are summarized in Table E.2.16. The Anchorage-Wi 11 ow segment will cross Kn i k Arm of Cook In 1et with a submarine cable.Further north,major stream crossings include the Little Susitna River and Willow Creek,both of which have been gaged. The Fairbanks-Healy line will make two crossings of the Nenana River and one of the Tanana River~bbtll 1 arge rivers and gaged. The intertie route between Willow and Healy will cross several dozen small creeks,many of whi ch are unnamed.Maj or streams, include the Talkeetna,Susitna,and Indian Rivers;the East Fork and Middle Fork of the Chulitna River;the Nenana River;Yanert Fork of the Nenana;and Healy Creek. The final leg of the transmission corridor,from Gold Creek to Watana Dam,will cross only one major river;the Susitna.Two smaller but sizeable tributaries are Devil Creek and Tsusena Creek,neither of which have been gaged • I I J I '\.I, I .J I / .(b)Water Qual ity At present,essentially no data is available for those sections of streams,rivers,and lakes that exist in close proximity to the proposed transmission corridors. E-2-30 I 1 i 3 -PROJECT IMPACT ON WATER qUALITY AND qUANTITY 3~1 -Proposed Project Reservoirs (a)Watana Reservoir Characteristics The Watana Reservoir will be operated at a normal maximum water level of 2185 feet above mean sea level,but will be allowed to surcharge to 2190 feet in late August during wet years.Average annual drawdown will be 105 feet with the maximum drawdown equal- ling 120 feet.During extreme flood events the reservoir will rise to 2193.3 for the 1 in 10,000 year flood and 2200.5 feet for the probable maximum flood respectively. ) l At elevation 2185,the reservoir will have a surface area of 38,000 acres and a total volume of 9.47 million acre-feet.Max- imum depth will be 735 feet and the corresponding mean depth will be 250 feet.The reservoir will have a retention time of 1.65 years.The shoreline length will be 183 miles.Within the Watana reservoir area the substrate classification varies great- ly.It consists predomin~nt1y of glacial,colluvial,and fluvial unconsolidated sediments and several bedrock lithologies.Many of these deposits are frozen. (b)Devil Canyon Reservoir Characteristics Devil Canyon reservoir will be operated at a normal maximum oper- ating level of 1455 feet above mean sea level.Average annual drawdown will be 28 feet with the maximum drawdown equalling 50 \1 feet.At elevation 1455 the reservoir has a surface area of 7800 acres and a volume of 1.09 million acre-feet.The maximum depth will be 565 feet and the mean depth 140 feet.The reservoir will have a retention time of 2.0 months.Shoreline length will total 76 miles.Materials forming the walls and floors of the reser- voir area are composed predomi nant1y of bedrock and gl aci a1 , colluvial,and fluvial materials. I \ I ) I / I J 3.2,-Watana Development For detail s of the physical features of the Watana development, refer to Section 1 of Exhibit A. (a)Watana Construction (i)Flows During construction of the diversions tunnel,the flow of the mainstem Susitna will be unaffected except during spring flood runoff.Upon completion of the diversion facilities in the autumn of 1986,closure of the upstream cofferdam wi 11 be comp1 eted and flow will be di verted through the lower diversion tunnel without any interruption in flow.Although flow will not be interrupted,a one mile E-2-31 1 J --'l I I r i ) '--'/ I J (i i) section of the Susitna River will be dewatered.No significant impacts should result from this action. Flows,velocities,and associated water levels upstream of- the proposed Watana damsite will be unaffected during con-. struction except for approximately one half mile upstream of the upstream cofferdam duri ng wi nter and two mil es up- stream during summer flood flows.During winter,ponding to elevation 1470 feet will be required to form a stable ice cover.However,the volume of water contained in this pond is insignificant relative to the total river flow. During the summer,the diversion intake gat~s will be fully opened to pass the natural flows resulting in a run-of- river operation.All flows up to approximately the mean annual flood will be passed through the lower diversion tunnel.Average velocities through the diversion tunnel will be 18,and 35 feet per second (f/s)at discharges of 20,000,and 40,000 cfs.respective1y.The mean annual flood of 40,800 cfs will cause higher than natural water levels for about several ·mi1es upstream of the cofferdam.The water 1evel wi 11 ri se at the upstream cofferdam from a natural water level of 1,468 feet to 1,520 feet.Two miles upstream,the water level will be about 4 feet higher than the natural water level during the mean annual flood. The two diversion tunnels are designed to pass the 1 in 50 year return period flood of 87,000 cfs with a maximum head- pond elevation of 1,536 feet.For flows up to the 1 in 50 year flood event,water levels and velocities downstream of the diversion tunnels will be the same as preproject 1evel s. Effects on Water Quality -Water Temperature Since the operation of the diversion structure will essentially be run-of-river,no impact on the temperature regime will occur downstream of the tunnel exit.A small· amount of ponding will occur early in the freeze-up stage to enhance the formation of a stable ice cover upstream, of the tunnel intake.This will not have a noticeable' effect downstream. Ice During freeze-up,the formation of an upstream stable ice cover by use of an ice-boom and some ponding to reduce approach velocities,will serve to protect the diversion works and maintain its flow capacity.The early forma- tion of the cover at this point will cause a more rapid E-2-32 . I I r ! I r I r l l. ,~ I.! I I; I , ! r) I j ice front progressi on upstream of the dams i teo The ice formed in the upper reach,which.normally feeds the downstream ice growth,will no longer be available. However the major contr i buter of frazi 1 ice wi 11 be the rapids through Devil Canyon as it now ;'s.Hence,no appreciable impact on ice formation downstream of Watana will occur due to the diversion scheme. The ice cover upstream of the damsite wi 11 thermally decay in place,since its movement downstream would be restri cted by the di versi on structure.Downstream of Devil Canyon the volume of ice in the cover will be essentially the same as the baseline conditions and "breakup would likely be similar to natural occurrences. -Suspended Sediments/Turbidity/Vertical Illumination During construction,suspended sediment concentrations and turbidity levels are expected to increase within the impoundment area,and for some distance downstream.This wi 11 result from the necessary construction acti vit i es within and immediately adjacent to the river,including: dredging and excavation of gravel fr'om borrow areas,ex- cavation of diversion tunnels,placement of cofferdams, vegetative clearing,blasting,gravel processing and de- wateri ng. The location and subsequent excavation of the material from proposed borrow sites will create the greatest potential for suspended sediment and turbidity problems. The proposed borrow sites,identified in Figure E2.74, are tentatively located in the river floodplain both upstream and downstream of the dam site.However,except for the materi al for the upstream cofferdam,the lower borrow material will be obtained from sites D and E. Materi al for the core of the mai n dam wi 11 be obtai ned from site D (10,000,000 yards).Material for the filters and shell of the main dam will be obtained from site E (52,000,000 yards).Borrow excavation will take pl"ace during the summer months when suspended sediment and turbidity values in the mainstem of the river are already quite high.As a result,incremental impacts during the summer should not be significant.Stockpiling of gravel is expected to alleviate the need for excavation during the winter,When the impact on overwintering fish due to changes in suspended load would be greatest.As a result of the proposed sChedUl',"n g of activities,impacts will ~ mi ni mi zed.However,it is i nevitab 1e that there will be some increases in suspended sediments and turbidity during winter,but these should be short-term a~ local ized.Downstream,turbidity and suspended sediment levels should remain essentially the same as baseline conditions. E-2-33 i' I) \ ) I } I I Decreases in summer and wi nter vertical ill umi nation are expected to be commensurate with any increased suspended sediment concentrations. Si nce summer flows wi 11 be passed through the di vers ion tunnel with no impoundment,no settling of suspended sed~ iments is expected to occur.The insignificant headpond that will be maintained during winter is not expected to affect the very low suspended sediment and turbidity levels present during the winter season. -Metals Sl i ght increases in the concentrat i on of trace metal s. could occur during construction when disturbances to soils and rock occur on the shoreline and in the river- bed.Such increases are expected to be below detect ion limits and thus would not indicate a change from baseline conditions described in Section 2.3 (a)(xiii). -Contamination by Petroleum Products Accidental spillage and leakage of petroleum products can contaminate water during construction.Lack of main- tenance and service to vehicles could increase the leak- age of fuel,lubricating oils,hydraulic fluid,anti- freeze,etc.In addition,poor storage and handling techni ques coul d 1ead to acci denta 1 spi 11 s.Gi ven the dynamic nature of the river,the contaminated water would be quickly diluted;however the potential for such sit- uations will be minimized.All state and federal reg- ulations governing the prevention and reclamation of accidental spills will be adhered to. -Concrete Contamination Construct i on of the Watana project will create a .poten- tial for concrete contamination of the Susitna River. The wastewater associated with the batching of concrete, if directly discharged to the river,could seriously de- grade downstream water quality and result in substantial mortality of fish.However,this potential problem should not occur since the wastewater will be neutralized and settling ponds will be employed to allow the concrete contami nants to settle pri or to the di scharge of the wastewater to the river. -Other No additional water quality impacts are anticipated. E-2-34 I r [ l [ [ { 1 l I 1 L ( I," 1\ i I' \ ) ) I (iii)Effects on Groundwater Conditions No impacts on groundwater wi 11 occur because of construc- t i on t ei ther in the impoundment area or downstream other than in the localized area of the project. (iv)Impact on Lakes and Streams in Impoundment Area There will be minor impacts on lakes and streams in the impoundment area due to excavation of borrow materi a 1. A1so,facil it i es wi 11 be constr ucted to house and su pport construction .personnel and their famil ies.The construction t operation and maintenance of these facilities is expected to impact the Tsusena and Deadman Creek drainage basins and some of the small lakes located between the two creeks near the dam site.For a compl ete discussion of these impacts refer to the discussion on Facilities in paragraph (vi)below. (v)Instream Flow Us~s For all reaches of the Susitna River except for the immedi- ate vicinity of the Watana damsite t there will be virtually no impact on navigation t transportation t recreation,fish- eries,riparian vegetation t wildlife habitat,waste load assi mil at i on or the freshwater recrui tment to Cook Inl et for flows less than the 1 in 50 year flood event. -Navigation and Transportation Si nce all flow wi 11 be di verted t there will only be an impact on navigation and transportation in the immediate vicinity of Watana dam and the diversion tunnel.The cofferdams will form an obstacle to navigation which will be difficult to circumvent.However,since this stretch of ri ver has very 1imited use due to the heavy rapi ds upstream and downstream of the site t impact wi 11 be minimal. -Fisheries During winter,the diversion gate will be partially closed to maintain a headpond with a water surface eleva- tion of 1,470 feet.This will cause velocities greater than 20 feet per second at the gate intake.This coup- 1ed with the 50 foot depth at the intake wi 11 impact fisheries.The impacts associated with the winter diver- sion are discussed in Chapter 3.2.3. During summer,the diversio~gates will be fully opened. This will permit downstream fish movement during low flows of about 10 t OOO cfs (equivalent velocity 9 feet per E-2-35 I \ r \ / l J The construction of the Watana power project will require the construction,operation and maintenance of support. faci1ties capable of providing the basic needs for a maxi- mum population of 4,720 people (3,600 in the construction camp and 1,120 in the village)(Acres,1982).The facili- ties,including roads,buildings,utilities,stores,rec- reation facilities,airports,etc.,will be constructed in stages duri ng the first three years (1985-1987)of the proposed ten-year constructi on peri ad.The camp and vi 1- 1age will be located approximately 2.5 miles northeast of the Watana damsite,between Deadman and Tsusena Creeks. The location and layout of the camp and village facilities are presented in Plates 34, 35,and 36 of Exhibit F. Water Supply Nearby Tsusena Creek will be utilized as the major source of water for the community (Plate 34).In addition, wells will be drilled in the Tsusena Creek alluvium as a backup water supply. During construction,the required capacity of the water treatment plant has been estimated at 1,000,000 gallons per day,or 700 gallons per minute (1.5 cfs)(Acres, 1982).Using the USGS regression equation described in" Table E2.15,30-day minimum flows (cfs),with recurrence interval s of 20 years were estimated for Tsusena Creek near the water supply intake.The low flow was estimated to be 17 cfs for the approximate 126 square mil es of drai nage bas in."As a resu1 t,no si gnifi cant adverse impacts are anticipated from the .maximum water supply withdrawal of 1.5 cfs.Further,a withdrawal of this E-2:-36 r r r f { r t 1 [ l I l -,( I) '/ " \ i magnitude should not occur during the low flow winter months since construction personnel will be significantly less than during summer. The water supply wi 11 be treated by chemical addit ion, flocculation,filtration and disinfection prior to its use.Disenfection should probably be with ozone to avoid having to dechlorinate.In addition,the water will be demineralized and aerated,if necessary. -Wastewater Treatment A secondar.y waste water treatment facility will treat all waste water prior to its di scharge into Deadman Creek (Plate 34). Treatment will reduce the BOO and total suspended solids (TSS)concentrations to levels acceptable to the Alaska Department of ,Environmental Conservation.The levels are 1 ikely to be 30 mg/l BOO and 30 mg/l TSS.The maximum volume of effluent,1 million gallons per day or 1.5 cfs, will be discharged to Deadman Creek which has a low flow of 27 cfs (see below).This will provide a dilution factor of about 17,thereby reducing BOO and TSS concentrations to about 2 mg/l after complete mixing under the worst case flow conditions (maximum effluent and low flow in Deadman Creek).Mixing will occur rapidly in the creek because of turbulent conditions. The effluent is not expected to cause any degredations of water quality in the 1 1/2 mile section of Deadman Creek between the waste water di scharge poi nt and the creek I s confluence with the Susitna River.Furthermore,no water quality problems are anticipated within the impoundment area or downstream on the Susitna River as a result of the input of this treated effluent.Using the USGS regression analysis,the one in 20 year,30-day low flow for Deadman Creek at the confluence with the Susitna,was estimated at 27 cfs •Flow at the poi nt of discharge whi ch is 1ess than two mil es upstream,are not expected to differ significantly. Constructi on of the waste water treatment faci 1i ty is expected to be completed in the first 12 months of the Watana construction schedule.Prior to its operation, all waste will be stored in a lagoon system for treatment at a later date.No raw sewage will be discharged to any water body. The applicant will obtain all the necessary DEC,EPA, DNR,and PHS permits for the water supply and wastewater discharge facilities. E-2-37 ! _\ \ -Construction,Maintenance and Operation Construction of the Watana camp,village,airstrips,etc. wi 11 cause impacts to water quality si mil ar to many of those occuring from dam construction.Increases in sed- imentation and turbidity levels are anticipated in the local drainage basns.(i.e.,Tsusena and Deadman Creeks). Even with extensi ve safety control s,acci dental spi 11 age and 1eakage of petrol eum products cou1 d occur creati ng localized contamination within the watershed. (b)Impoundment of Watana Reservoir (i)Reservoir Filling Criteria The fi 11 i ng of the Watana reservoi r is schedu1 ed to com- mence in May 1991. -Minimum downstream target flows In the selection of minimum target flows,fishery con- cerns and economics were the two controlling factors. A1 though not unimportant in the overall impact assess- ment,other i nstream flow uses,were determi ned not to have a sig-nificant influence on the selection of minimum downstream target flows.However,instream uses such as navigation and transportation,recreation,and waste load assimilation are closely related to the instream flow requirements of the fishery resources. Minimum downstream target flows will be provided at Gold Creek since Gold Creek flows are judged to be representa- tive of the Talkeetna to Devil Canyon reach where down- stream impacts will be greatest.The minimum target flows at Gold Creek will be attained by releasing that flow necessary from the Watana impoundment,which when added to the flow contribution from the intervening drainage area between Watana and Gold Creek,will equal the minimum Gold Creek target flow.The absolute minimum flow release at Watana will be 1,000 cfs or natural flows,whichever is less.During filling,flows at Gold Creek will be monitored and the flow at Watana adjusted as necessary to provide the required Gold Creek flow. Table E.2.17 illustrates the targeted minimum Gold Creek flows.The minimum downstream flow of 1000 cfs from November through April is somewhat lower than the average winter flow at Gold Creek. From May to the 1ast week of July,the target flow will be increased to 6,000 cfs to allow for mainstem fishery movement.During June,it may be deslrab1e to spike the flows to trigger the outmigration of salmon fry from the sloughs.(Schmidt,1982 personal communication).It is believed that the outmigration is triggered by a combina- tion of stage,discharge and temperature.Trihey (1982) has observed that the fry outmi grate duri ng the fall i ng limb of the spring flood hydrograph. E-2-38 J f r - , I 1 f I J t t l t ( y r--y I l (i i ) The 6,000 cfs Gold Creek flow will provide a mlnlmum of 2 feet of river stage for mainstem fishery movement at all 65 surveyed cross sections between Ta lkeetna and Devil Canyon.Fi gure E2.75 ill ustrates computed water surface elevations for various discharges at cross section 32 located near Sherman (RM 130).(Accuracy is +1 foot). This cross section is believed to be the shallowest in the Talkeetna to Devil Canyon reach.The estimated water surface elevation for a discharge of 6000 cfs indicates that the depth is greater than 2 feet. Du'ri ng the 1ast 5 days of July,flows wi 11 be increased from 6,000 cfs to 12,000 cfs in increments of approxi- mate ly 1,500 cfs per day..Flows will be rna i nta i ned at 12,000 cfs from August 1 through mid-September to coin- cide approximately with the sockeye and chum spawning season·in the sloughs upstream of Talkeetna.Adverse impacts to fish resulting from this flow regime are discussed in Chapter 3.2.3. After 15 September,flows W111 be reduced to 6,000 cfs in daily increments of 1,500 cfs and then held constant un- til October when they wi 11 be further reduced to 2,000 cfs.In November,the flow will be lowered to 1,000 cfs. -Flood Flows Taking into account the 30,000 cfs discharge capability of the low level outlet,sufficient storage will be made available during the filling sequence such that flood volumes for all floods up to the 250 year recurrence in- terval flood can be temporarily stored in the reservoir without endangering the main dam.Whenever this storage criteria is violated,discharge from the Watana reservoir will be increased up to the maximum capacity of the out- let to lowe~the reservoir level behind the dam. Reservoir Filling Schedule and Impact on Flows Using the reservoir filling criteria,three simulated reservoir filling sequences were examined to determine the likely filling sequence and probable deviations.As ap- proximately three years will be required to bring the res- ervoir to its normal operating 1evel,three year runni ng averages of the total annual flow volume at Gold Creek were computed.The probabil ity of occurrence for each of the three year average values was then determined.Using the 10,50,and 90 percent excee<;lence probabil ity vol urnes and E-2-39 ( -~Y the long term average monthly Gold Creek flow distribution, Gold Creek flow hydrographs were synthesized for each probability.An identical process was used to synthesize the 10,50,and 90 percent probability volumes and flow distributions at Watana.The intermediate flow contribution was taken as the difference between the Watana and Gold Creek monthly flows.Then using the downstream flow criteria and the flow values at Watana and Gold Creek, the filling sequence for the three probabilities was determined ~yrepeating the annual flow sequence until the reservoir was filled. The reservoir water levels and the Gold Creek flows for the three fill i og cases consi dere'd are illustrated in Fi gure E2.76.Under average conditions the reservoir wou.ld fill sufficiently by autumn 1992 to allow testing and com- missioning of the units to commence.However,the reser- voir would not be filled to its normal operating level ~ until the following summer.There is a 10 percent chance that the reservoir would not be sufficent1y full to permit the start of testing and commissioning until late spring 1993.Only about one month is saved over the average filling time if a wet sequence occurs.This is because the flood protection criteria is violated and flow must be by- passed rather than stored. The Watana discharges for the high (10 percent),mean (50 percent)and low (90 percent)flow cases cons i dered are compared to the Watana inflow in Table E2.18.For the average hydrologic case,pre-project discharge for the May-October peri od is reduced by approx i mate ly 60 percent during the filling period.However,from November through April there is little difference. For the Devil Canyon to Talkeetna reach,Gold Creek flows are considered representative.Monthly pre-project and filling flows at Gold Creek for the wet,(10 percent),mean (50 percent),.and dry (90 percent)sequences are ill us- trated in Table E2.19.Percentage summer and winter flow changes are simi 1ar to those at Watana but are somewhat reduced because of additional tributary inflow.For the mean case,August monthly flow at Gold Creek is reduced by 45 percent (21,900 cfs to 12,000 cfs)when the reservoir is capable of storing all flow less the downstream flow re- quirement. Flows will be altered in the Talkeetna to Cook Inlet reach, but because of significant tributary contributions the impact on summer flows will be greatly reduced with dis- tance downstream.Table E2.20 is a comparison of mean pre- project monthly flows and monthly flows duri ng reservoir filling at Sunshine and Susitna Station.Pre-project flows are based on the long-term average ratio between the respective stations and Gold Creek.Filling flows are pre-project flows reduced by the flow stored in the reservoir. E-2-40 I r f r I 1 r 1 l ( -----1 \, ! j l -( -Floods The reservoir filling criteria,dictates that available storage vol ume in the reservoir must provide,protecti on for all floods up to the 250 year recurrence interval flood.Thus,the reservoir must be capabl e of stori ng all flood inflow except for the flow which can be dis- charged through the outlet facilities during the flood event.The maximum Watana discharge of the outlet facil- ities is 30,000 cfs.A maximum flow at Watana at 30,000 cfs represents a substantial flood peak reduction which will reduce downstream flood peaks substantially as far downstream as Talkeetna.For example,the once in fifty year flood at Gold Creek would be reduced from 106,000 cfs to 49,000 cfs. After the flood event,the outlet facility will continue to discharge at its maximum capacity until the storage volume criteria is reestablished.This will cause .the flood duration to be extended beyond its normal duration although at a reduced flow as noted above. The flood frequency curve for Watana during reservoir filling is illustrated in Figure E.2.77. -Flow Variability The variability of flow in the Watana to Talkeetna reach will be altered.Under natural conditions substantial change in flows can occur daily.This flow variability will be reduced during filling.Using August,1958 as a example,Figure E.2.78 shows the daily flow variation that would occur.The average monthly flow of 22,540 cfs during August,1958 yields a value close to the long term average monthly discharge of 22,000 cfs.Superimposed on Figure E.2.78 are the flow variations that could occur under filling conditions with the August 1958 inflow, first,assuming that the reservoir was capable of accommodat i ng the i nfl ow and second,assumi ng that the reservoir storage criteria was violated (i.e.,30,000 cfs discharge at Watana).Both Gold Creek hydrographs have reduced flood peaks.In filling sequence 1,outflow is greater than i nfl ow at Watana on the receedi ng 1 i mb of the hydrograph in order to meet the reservoi r storage volume criteria.Hence during this time period,Gold Creek flows are greater than natural.In this example it was assumed that ongoing construction did not permit additional storage.In reality,the dam height will be increasing and additional storage would be permitted, thus reduci ng the requi red outflow from Watana.Th i s would correspondingly reduce the Gold Creek discharge. E-2-41 ( ) \ ( In filling sequence 2,Gold Creek flow is constant at 12,000 cfs.However,at Watana,flow would be 4,350 cfs at the peak and about 10,000 cfs when the natural Gold Creek flow drops to 12,000 cfs. Further downsteam,the variability of flow for both sequences will increase as a result of tributary inflow, but will be less than under natural conditions. (i i i)!U ver Morphology During the filling of Watana reservoir,the trapping of bed- load and suspended sediment by the reservoir will greatly reduce the sediment transport by the Susitna River in the Watana-Talkeetna reach.Except for isolated areas,bedload movement will remain limited over this reach because of the armor layer and the low flows.The lack.of suspended sedi- ments will significantly reduce siltation in calmer areas. The Susitna River main channel will tend to become more defi ned with a narrower channel in thi s reach.The mai n channel river pattern will strive for a tighter,better de- fined meander pattern within the existing banks.A trend of channel width reduction by encroachment of vegetation will begin,and will continue during reservoir operation.Tribu- tary streams,including Portage Creek,Indian River,Gold Creek,and Fourth of July Creek,will extend their alluvial fans into the river.Figure E.2.79 illustrates the influence of the mai nstemSusitna Ri ver on the sedimentation process occurri ng at the mouth of the tri butari es.Overflow into most of the side-channels will not occur,as high flows will be greatly reduced.The backwater effects at the mouths of side-channels and sloughs will be significantly reduced. At the Chulitna confluence,the Chulitna River is expected to expand and extend its alluvial deposits.Reduced summer flows in th.e Susitna River may allow the Chulitna River to extend its alluvial deposits to the·east and south.However, high flows in the Chulitna River may cause rapid channel changes,inducing the main channel to migrate to the west. This would tend to relocate the deposition to the west. Downstream of the Susitna-Chulitna confluence,the pre- project mean annual bankfull flood will now have a recurrence interval of five to ten years.This will tend to decrease the fr·equency of occurrence of both bed materi a 1 movement and,consequently,of changes in braided channel shape,form and network.A trend toward relative stabil ization of the floodplain features will begin,but this would occur over a long period of time (R&M,1982a). (iv)Effects on Water Quality Beginning with the filling ~f the reservoir,many of the physical,chemical and biological processes common to·a E-2-42 [ I I J f r r [ I [ I I l I I I I ( .( lentic environment should begin to appear.Some of the more important processes include sedimentation,leaching,nutrient enrichment,stratification,evaporation and ice cover.These processes are expected to interact to alter the water quality conditions associated with the natural riverine conditions that presently exist.A summary discussion of the processes and their interactions is provided in Peterson and Nichol~ (1982)• -Water Temperature During the first summer of filling,the temperature in the Watana reservoir will be essentially a composite of the inflow temperature,increased somewhat by the effects of solar heating.The reservoir will fill very rapidly (to about a 400 foot depth by the end of summer)and the effects of solar heating will not penetrate to th~depth at which the outlet is located.'Therefore,outlet temperatures during the first summer of filling should be an average of the existing river water temperatures with some lagging with the inflow water temperatures. During fall,the reservoir will gradually cool to 4°C. Once at this temperature the low level outlet will con- tinue to discharge water at just above 4°C until the reservoir water 1evel has increased to where the fi xed cone valves can be used. Downstream of the Watana development the water tempera- ture will be modified by heat exchange with the atmos- phere.The filling sequence will cover two winter peri ods and the temperature at the downstream end of Devil Canyon will reach O°C at or about the beginning of November in the first year and toward the end of October in the second.This will have the effect of lagging the downstream temperatures by about 5 weeks from the base,,: liner.Further downstream,the lagging in temperatures will be reduced as cl imatic conditions continue to in- fluence the water temperature. During the second summer of filling,outlet temperatures will be 4°C.Downstream of Watana,the water temperature will increase but,will be well below normal water temperatures.~ -Ice With the delay of freezing water temperatures,the entire ice formation process will occur 3-4 weeks later than for natural conditions.However,due to the lower flows the severity of jams will be diminshed and the staging due to ice will be less than presently experienced.At breakup, E-2-43 I I. the reduced flows in combination with the diminished jamming in the river,will tend to produce a less severe breakup than currently occurs. -Suspended Sediments/Turbidity/Vertical Illumination •Watana Reservoir As the reservoir beings to fill,velocities will be re- duced and deposition of the larger suspended sediment particles will occur.Initially,all but the larger par- ticles will pass through the reservoir,but with more and more water impounded,smaller diameter particles will settl e.As the reservoir approaches normal operati ng levels,the percentage of particles settling will be sim- ilar to that occurring during reservoir operation.How- ever,since during filling,water will be passed through the low level outlet which is at invert elevation 1490 feet,whereas during operation it will be drawn from above elevation 2065 feet,larger particles would be expected to pass through the.reservoir dur i ng fi 11 i ng than during operation (The deposition process during reservoir operation is discussed in detail in Section 3.2 (c)(iii).). During the filling process,reservoir turbidity will de- cr.ease in conjunction with the settling of suspended sed- iments.Turbidity will be highest at the upper end of the reservoir where the Susitna Ri ver enters.Turbi d interflows and underflows may occur during summer months, depending on the relative densities of the reservoir and river waters.Turbidity levels in the winter are ex- pected to decrease significantly from summer levels,how- ever,turbidity is likely to be greater than pre-project wi nter level s. Vertical illumination in the reservoir will decrease dur- ing breakup as flow begins to bring glacial silts into the reservoir.Vertical illumination during the s-ummer wi 11 vary,dependi ng on where the ri ver water fi nds 'its equilibrium depth (overflow,interf1ow,or underflow). Data from glacially fed Eklutna Lake indicates that vertical illumination will not exceed 4 meters during the mid-summer months (Figure E.2.80).Vertical illumination will gradually increase during the autumn as glacial input decreases. During the filling process additional suspended sediments will be introduced to the reservoir by the slumping of the valley walls and continued construction activities. The slumping of valley walls will provide intermittent quantities of suspended sediments.Although no quantita- tive estimates of this impact are available,it is an- ticipated that these impacts will be localized,of short E-2-44 I r 1 I [ [ L [ L [ [ l L J I I duration,and thus not very significant.However,slump- i ng is expected to cont i nue after operation of the pro- ject begins until equilibrium is attained.Construction activities,such as the removal of timber from within the proposed impoundment area are also expected to contribute to increased suspended sediment concentrat ions and tur- bidity levels and decreased vertical illumination.Once removed,the lack of soil-stabilizing vegetative cover will likely accelerate wall slumping.However,the in- crease in suspended sediments due to valley wall slumping will be significantly less the reduction due to the sed- i mentat i on process and thus the ri ver will be c1 earer than under natural conditions. Watana to Talkeetna Maximum particle sizes passing through the project area downstream,will decrease from about 500 mi crons dur i ng pre-project conditions to about 5 microns as filling progresses.As can be observed from the part i cl e si ze distribution (Figure E.2.36)this results in a retention .of about 80 percent of the pre-project suspended sediment at Watana.Because of the cl ear water tributary i nf1 ow in the Watana to Talkeetna reach,further reduction of the suspended sediment concentration will occur as the flow moves downstream.During high tributary flow periods,additional suspended sediment will be added to the river by the tributaries.Talus slides may also contri bute to the downstream suspended sediment concen- trations.In general,the suspended sediment concentra- tion in the Watana to Talkeetna reach will be reduced by approximately 80 percent duri ng the summer months and slig~tly increased during the winter months. Downstream summer turbidity levels will be reduced to an estimated 30-50 NTU.Winter turbidity levels,although not presently quantifiable,will be increased above natural levels of near zero.Because of the reduced tur- bidity in summer,the vertical illumination will be en- hanced.Winter vertical illumination will be reduced • •Talkeetna to Cook Inlet In the Talkeetna to Cook Inlet reach,the suspended sedi- ment and turbidity levels during summer will decrease s1i ght1y from pre-project 1eve 1 s.The Chu1 i tna Ri ver is a major sediment contributor to the Susitna with 28 per- cent of its drainage area covered by glacier.As such, it wi 11 tend to keep the suspended sediment concentra- t ions hi gh duri ng summer.Therefore,the summer char- acter of this reach will not change significantly. E-2-45 j l -Dissolved Oxygen Initially,during the 3-year filling process,the reservoir D.O.levels should approximate riverine conditions.As filling progresses,some weak stratification may begin to develop,but no substanti a1 decreases in di ssol ved oxygen levels are anticipated.The volume of freshwater inflow, the effects of wind and waves,and the location of the out- 1et structure at the bottom of the re~ervoir are expected to keep the reservoir fairly well mixed,thereby replenish- ing oxygen levels in the hypolimnion. No significant biochemical oxygen demand is anticipated. The timber in the reservoir area will be cleared,thereby eliminating the associated oxygen demand that would be cre- ated by the inundation and decomposition of this vegeta- tion.Further,the chemical oxygen demand (COD)in the Susitna River is quite low.COD levels measured upstream at Vee Canyon during 1980 and 1981,averaged 16 mg/l. No significant BOD loading is expected from the construc- tion camp and village. As previously noted,a low level outlet will be utilized for di schargi ng water.Therefore,the 1evel s of oxygen immediately downstream of the outlet could be slightly reduced.However,pre-project values will be established withi n a short di stance downstream of the outlet due to reaeration enhanced by the turbulent nature of the river. -Nitrogen Supersaturation Nitrogen supersaturation of water below a dam is possible in certain seasons,extending a considerable distance downstream.The detrimental impact of nitrogen supersatur- ation is its lethal effect on fish.If dissolved gases reach lethal levels of supersaturation,a fish kill due to gas embol isms may result for mil es downstream of an im- poundment (Turkheim,1975). Nitrogen supersaturation can be caused by passing water over a high spillway into a deep plunge pool.The factors influencing this phenomenon include the depth of the plunge pool,the hei ght of the spi 11 way and the amount of water bei ng spi 11 ed.Si nce all flow wi 11 be passed through the low level diversion tunnel and no spilling of water will occur at the Watana damsite,this problem will not exist duri ng fi 11 i ng. -Nutrients Two opposing factors will affect nutrient concentrations during the filling process.First,initial inundation will likely cause an increase in nutrient concentrations. E-2-46 t r [ i r ( I r [ L I ~ L l L l ( 'r-... \ -1 I \ (' \ I ' I I ! {~ ( I \ I I ''- Second t sedimentation will strip some nutrients from the water column.The magnitude of net change in nutrient concentrations is unknown t but it is likely that nutrient concentrat ions wi 11 increase for at 1east a short-term during fill ing. -Other No significant chang;~s in any other water qual ity par- ameters are ant i ci pate,.l. (v)Effects on Groundwater Conditions -Mainstem Alluvial gravels in the river and tributary bottoms will be inundated.No significant aquifers are known to be in the reservoir area t other than theunconfi ned aqui fers at the relic channel and in valley bottoms. Summer releases from the reservoir during filling are dis- cussed in Section 3.2(b)(i).As a result of the decreased summer ,f1ows t water levels will be reduced t especially above Talkeetna.This will in turn cause a reduction in groundwater levels,downstream but the groundwater level changes will be confined to the river floodplain area.The groundwater table will be reduced by about 2 feet in summer near the shoreline with less change occurring with distance away from the river. A s imil ar process will occur downstream of Talkeetna t but the changes in groundwater levels will be of less magnitude due to the decreased effect on river stages. -Impacts on Sloughs The reduced mainstem flows and subsequently lower Susitna River water levels will reduce the water level gradient between the mai nstem and the sloughs.At 1ocat ions where slough upwelling 'is unaffected by mainstem backwater effects t the reduced gradient will result in reduced slough upwell i ng rates.However t an analysi s of mai nstem water elevations at the decreased flow rate and the slough up- welling elevations t indicates a continued positive flow toward these upwell i ng areas with the except i on that the intersection of the slough and the groundwater table will move downstream.Data to confirm the areal extent of upwelling at low flows is unavailable at this time. E-2-47 The thalweg profile in slough 9 and computed mainstem water surface profiles in the vicinity of Slough 9 are illus- trated in Figure E.2.81.The thalweg profile taken at right angles to the mainstem flow together with the main- stem water levels show that upwelling will continue at lower mainstem flows.(The water surface profiles which were computed using HEC-2 a.re sufficiently accurate to illustrate the relationship).It should also be noted that the groundwater driving head is more in an upstream- downstream direction than in a direction perpendicular to the mainstem.This can in general be attributed to the 1ocat i on of most sloughs at natura 1 bends in the river. The di stance from the mai nstem at the head end of the sloughs to the rna i nstem at the mouth of the sloughs ;-s usually shorter through the sloughs than along the mai n- stem.. At the slough upwelling locations which are affected by the mainstem backwater,the groundwater gradient between main- stem and slough is relatively unaffected by discharge until backwater effects are ·no longer present at the upwelling 1ocat i on.(As the mai nstem water 1eve 1 decreases at the head end of the slough,there is a corresponding decrease in mairistem water level at the mouth of the slough where the backwater is controlled.Therefore,the gradient betweefi the mainstem water level upstream and the backwater elevation in the slough is essentially unchanged.)Hence upwell i ng rates in backwater areas wou1 d remai n virtually unchanged until the area is no longer affected by back- water.At that time the upwelling would behave as dis- cussed above. Under ice conditions the mainstem water levels increase, resulting in an increased head differential between main- stem and slough,and increased upwelling in the sloughs. Under reservoir filling conditions during winter,discharge will be reduced to about 1000 cfs at Gold Creek during the freeze-up period.This will result in reduced staging from pre-project ice staging levels.Hence,during winter,the mainstem-slough water level differential will be reduced with a corresponding reduction in upwelling area. In summary,based on available information to date,up- welling in sloughs will continue but at an equal or slight- ly reduced rate from the natural rate.Additionally,the upper ends of some sloughs maybe dewatered because of the lower groundwater table associ ated with the decrease in mainstem water levels. (vi)Impacts on Lakes and Streams Several tundra lakes will be inundated as the reservoir approaches full pool.The mouths of tributary streams E-2-48 I f 1 [ [ [ r L L L L enteri ng the reservoir wi 11 be inundated for severa tJmil es (Sec.2.4 (b)).Bedload and suspended sediment carried by these streams will be deposited at or near the new mouths of the streams as the river mouths move upstream during the filling process.No significant impacts to Tsusena or Deadman Creeks are anticipated from their use as water supply and waste recipient,respectively. (vii)Effects on Instream Flow Uses -Fishery ;Zesources,Riparian Vegetation,and Wildlife Habitat Impacts on fishery resources,riparian vegetation and wild- life habitat during the filling process are discussed more fully in Chapter 3.As summer flows are reduced,fish access to slough habitats will be decreased.Since temper- atures of upwelling groundwater in sloughs are expected to be unchanged and upwelling should continue at most 10ca- t ions,though pos sib 1y at a reduced rate,impacts on the lncubation of sa1monid eggs are not expected to be severe. -Navigation and Transportation Once impoundment of the reservoir commences,the character of the ri ver immedi ate1y lJilstream of the dam wi 11 change from a fast-flowing river with numerous rapids to a still- water reservoir.The reservoir will ultimately extend 54 miles upstream,just downstream of the confluence with the Tyone Ri ver,and will inundate the major rapi ds at Vee Canyon when the reservoir reaches full pool.The reservoir will allow increased boat traffic to this reach of river by decreasing the navigational difficulties. The reduced summer flows released from the reservoir during filling could reduce the navigation difficulties between Watana and Devil Canyon during the summer months.However, the lower segment of this reach from Devil Creek to Devil Canyon will still consist of heavy white-water rapids suit- able only for expert kayakers. Navigational difficulties between Devil Canyon and the con- f1 uence wi th the Chu1 i tna Ri ver wi 11 be increased due to shallower water and a somewhat constricted channel.Al- though there will be sufficient depth in the river to navi- gate it,greater care will be required to avoid grounding. There will be less floating debris in this reach of the river,which will reduce the navigational danger somewhat. There will be little impact on navigation below the conflu- ence of the Chulitna River.The Susitna River is highly braided from Talkeetna to Cook Inlet with numerous channels which can change rapidly due to the high bedload movement E-2-49 \ ) -1 \ and readily erodible bed material.Navigation can be difficult at present and knowledge of the river is beneficial at low flows.The reduced summer flows from the Susitna River will be somewhat compensated for by the high flows from other tributaries.No impacts near the existing boat access points of Susitna Landing,Kaskwitna River or Willow Creek have been identified.Minor restrictions on navigation may occur at the upstream access to Alexander Slough,but this would occur only in low streamflow years when the other-tributaries also have low flow. -Recreation Information on recreation can be found in Chapter 7. -Waste Assimilative Capacity The previously noted,reductions to downstream summer flows could result in a slight reduction in the waste assimila- tive capacity of the river.However,no significant impact is anticipated given the limited sources of waste loading on the river (see Section 3.2(a)(ii)). -Freshwater Recruitment to Estuaries During filling,under av'erage flow conditions,the mean annual freshwater inflow to Cook Inlet will be reduced by about 12 percent.This will cause a few parts per thou- sand increase in the natural salinity conditions.How- ever,the salinity change would still be within the range of normal variation.If filling were to take place during an average hydrologic sequence,then the annual freshwater input to Cook Inlet would still be greater than the existing annual flows into Cook Inlet 15 percent of the time. During a dry flow sequence,the downstream flow require- ments at Gold Creek would be maintained.Thus,a smaller percentage of the Gold Creek flow is available for stor- age.Consequently the percent reduct ion in fresh water i nfl ow into Cook In 1et is 1ess for a sequence of dry years than for average conditions. The higher Cook Inlet salinities will last only until project operation,at which time a new equilibrium wil be established as described in Section 3.2(c)(v). E-2-50 l [ 1 f f r I [ { I { 1 ( [ t l l \ \ ( \ l \ ,L (c) • Watana Operation (i)Flows -Project Operation Watana will be operated in a storage-and-release mode, such that summer flows will be captured for release in wi nter.Generally,the Watana reservoir wi 11 be at or near its normal maximum operating level of 2185 feet each year at the end of September.Gradually the reservoir will be drawn down to meet winter energy demand.In early May,the reservoir will reach its minimum annual 1eve 1 and then begi n to refi 11 fr am the spr i ng melt. Flow in excess of both the downstream flow requirements and power needs will be stored during the summer until the reservoir reaches the normal maximum operating level of 2185 feet.Once the reservoir is at this elevation, flow above that required for power will be wasted.After the threat of significant flooding has passed in late August,the reservoir wi 11 be all owed to surcharge to 2190 feet to minimize wasting of water in late august and September.Then,at the end of September,the annual cycle ~ill-Pe r~peated• •Minimum Downstream Target Flows During project operation,minimum Gold Creek target flows from May through September will be unchanged from those duri ng reservoir impoundment except that flows from October to Apri 1 wi 11 be mai ntai ned at or above 5,000 cfs.It should be noted that these flows are minimum target flows.In reality,project operation flows will normally be greater than the targeted mini- mum flows during winter.During May,June,July and October,operat i ana 1 flows wi 11 a1so normally be greater than the mi ni mums.The 1ate Ju ly,August,and September flows will probably coincide very closely with the mi nimum requirements.The mi ni mum tar get flows during operation are shown in Table E.2.17. If during summer,the natural flows fall below the Gold Creek minimum target,then these flows will be augment- ed to maintain the downstream flow requirement • •Monthly Energy Simulations A monthly energy simulation program was run using the 32 years of Watana synthesized flow data given in Table E2.2 except that the extreme drought (recurrence inter- val greater than one in 500 years)which occurred in water year 1969,dominated the analysis and was there- fore modified to reflect a drought with recurrence interval of one in 32 years for energy planning and E-2-51 drawdown optimization.Energy production was optim- ized,taking into account the reservoir operating criteria and the downstream flow requirements.The energy simulation program is discussed in Volume 4, Appendix A of the Feasibility Study (Acres,1982). Monthly maximum ,mi ni mum,and medi an Watana reservoir levels for the 32 year simulation are illustrated in Figure E.2.82 • •Daily Operation In an effort to stabilize downstream flows,Watana will be operated as a base loaded plant until Devil Canyon is completed.This will produce daily flows that are virtually constant most of the year.During summer it may be economically desirable to vary flow on a daily basis to take advantage of the flow contribution down- stream of Watana to meet the flow requirements at Gold Creek.This would yield stable flows at Gold Creek, but somewhat var i ab 1e ri ver flows between Watana and Portage Creek. -Mean M~and Annual Flows Monthly discharges at Watana for the 32 year period were computed using the monthly energy simulation program and are presented in Table E.2.21.The maximum,mean,and minimum flows for each month are summarized in Table E.2.22.Pre-project flows are also presented for comparison.In general,powerhouse flows from October through April will be much greater than natural flows. For example,in March the operational flows will be eight times greater than natural river flow.Average post pro- ject flow for May will be about 30 percent less than the natural flow.Mean daily post project flows during May wi 11 be si mil ar for each day of the month.In contrast, existing baseline flows vary considerably from the start of the month to the end of the month due to the timing of the snowmelt.Flows during June,July,August and September will be substantially reduced,to effect reser- voir fi 11 i ng. Pre and post project montly flows at Gol d Creek are listed in Tables E2.23-and E2.24.A summary is present- ed in Table E2.25.The comparison is similar to that for Watana although the pre-pr oj ect/post-pr oj ect percentage change is less. Further downstream at the Sunshine and Susitna Station, gaging station pre-and-post project flow differences will become less significant.During July,average monthly flows will be reduced by eleven percent at Susitna E-2-52 l f [ f r [ [ f l l l t L ,( 1 l \ ,I I ( ( \ ( ( l I ,\ Station.However,during the winter,flows will be 100 percent greater than exi st i ng condi t ions.Monthly pre- and post-project flows at the Sunshine and Susitna Stations are tabulated in Tables E.2.26 through E.2.29 and summarized in E2.30 and E2.31. Mea n an nua 1 flow will remain the same at a 11 stat ions. However,flow will be redistributed from the summer months to the winter months. -Floods •Spring Floods For the 32 years si mu1 ated,Watana reservoi r had suf- ficient storage capacity to absorb all floods.The largest flood of record,June 7,1964,had a peak dis- charge of 90,700 cfs at Gold Creek,corresponding to an annua.l flood recurrence interval of better than 20 years.This flood provided the largest mean monthly inflow on record at Gold Creek,50,580 cfs and contain- ed the largest flood volume on record.However,even with this large a f1ooo,the simulated reservoir level increased only 49 feet fr~vation 2089 to elevation 2138.A further 47 feet of storage were available before reservoir spillage would have occurred. The flood volume for a May-July once in fifty year flood was determined to be 2.3 million acre feet (R&M, 1981a).This is equivalent to the storage volume con- tained between elevation 2117 and 2185,neglecting dis- charge.Since the maximum elevation at the beginning of June was always less than 2117 during the simula- tion,the 50 year flood volume can be stored without spillage if it occurs in June.Assuming the maximum June 30th water level in the simulation,if ·the flood event occurs in July,the once in fifty year flood volume can also be accommodated without exceeding E1 evati on 2185 if the powerhouse di scharge averages 10,000 cfs.Thus,for flows up to the once in fi fty year spri ng flood event,Watana reservoir capacity is capable of totally absorbing the flood without spillage. Only for flood events greater than the once in fifty year event and after the reservoir elevation reaches 2185.5 feet,will the powerhouse and outlet facilities will be operated to match inflow up to the full operat- ing capacity of the outlet facilities and powerhouse. If inflow continues to be greater than outflow,the reservoir will gradually rise to Elevation 2193.At that time,the main spillway gates will be opened and operated so that the out flow matches the i nfl ow.The E-2-53 ( I l I l \ i I ; l l ( ( i I j main spillway will be able to handle floods up to the once in 10,000-year event.Peak inflow for a once in 10,000-year flood will exceed outflow capacity resulting in a slight increase in water level above 2193 feet.The discharges and water levels associated with a once in 10,OOO-year flood are shown in Fi gure Eo 2.83. If the probable maximum flood were to occur,the main s pi 11 way wi 11 be operated to match i nfl ow unt il the capacity of the spillwc.y is exceeded.·The reservoir elevation would rise until it reached Elevation 2200. At this elevation,the erodable dike in the emergency spillway would be eroded and the emergency spillway would operate.The resulting total outflow through all the discharge structures would be 15,000 cfs less than .the probable maximum flood (PMF)of 326,000 cfs.The i nfl o.w and outflow hydrographs for the PMF are ill us- trated in Figure E.2.83 • •Summer Floods For floods occurri ng in August and September,it is probable that the Watan~rvoir could reach Eleva- tion 2185.Design considerations were therefore estab- lished to ensure that the powerhouse and outlet facili- ties will have sufficient capacity to pass the once in fifty year summer flood without operating the main spillway as the resultant nitrogen supersaturation caul d.be detri menta 1 to downstream fi sher i es.Our i ng the flood,the reservoir will be allowed to surcharge to Elevation 2193. An analysis of the once in fifty year summer flood was carri ed out assumi ng that the reservoi r was at 2185 feet when the flood commenced.The inflow flood hydro- graph at Watana was derived by multiplying the mean annual flood peak at Watana by the ratio of the once in two year summer flood peak at Gold Creek to mean annual flood peak at Gold Creek to obtain the once in two year summer flood peak at Watana.This value was then multiplied by the ratio of the once in fifty year summer flood to the once in two year summer flood at Gold Creek,to obtain the Watana once in fifty year summer flood peak of 64,500 cfs.The August to October dimensionless hydrograph (R&M,1981a)was next multi- p1i ed by the Watana peak flood flow to obta in the in ... flow hydrograph.The i nfl ow was then routed through the reservoir to obtain the outflow hydrograph.Maxi- mum outflow is the sum of the outlet facility discharge and the powerhouse fl ows.Flows and associ ated water levels are illustrated in Figure E.2.83. E-2-54 r { l r [ [ l 1 l L l l I -1 1 If summer floods of 1esser magnitude than the fifty year event occur with the reservoir full,i nf1 ow will match outflow up to the discharge capabil ity of the outlet facilities and powerhouse. August floods occurring in the 32 year energy simula- tion period did not cause the reservoir to exceed ele- vation 2190 feet.Hence,no spills occurred.The sim- ulation included the August 15,1967 flood.This flood had an instantaneous peak of 80,200 cfs at Gold Creek and an equi va 1ent return of once in 65 years;thus demonstrating the conservative nature of the above analysis. Downstream of Watana,flood flows at Go 1d Creek,·wi 11 be reduced corresponding to the reduction in flood flow at Watana.Flood peaks at Sunshine and Susitna Station will also be attenuated,but to a lesser extent • •The annual and summer flood frequency curves for Watana are illustrated in Figure E.2.84. -Flow Variability Under normal hydrologic conditions,flow from the Watana development will be totally regul ated.The downstream flow will be controlled by one of the following criteria: downstream flow requirements,·minimum power demand,or reservoir level operating rule curve.There will gener- ally not be significant changes in mean daily flow from one day to the next.However,there can be significant vari ati ons in di scharge from one season to the next anq for the same month from one year to the next. Monthly and annual flow durati on curves based on the monthly average flows for pre-project and post-project operating conditions for the simulation period are illustrated in Figures E.2.85 through E.2.88 for Watana, Gold Creek,Sunshine,and Susitna Station.The flow durat i on curves show a dimi ni shed pre-and-post-project difference with distance downstream of Watana. (ii)River Morphology Impacts on river morphology during Watana operation will be similar to those occurring during reservor impoundment (Section 3.2(b)(ii),although flow levels will generally be increased for power operations.The reduction in stream- flow peaks,and the trapping of bedload and suspended sedi- ments will continue to significantly reduce morphological changes in the river above the Susitna-Chulitna confluence. E-2-55 1 I -1 I ! i ( ( I 1 I j ( ; ( ! l I 1 The mainstem river will tend to become tighter and better defined.Channel width reduction by vegetation encroachment will continue. The effects of ice forces duri ng breakup on the ri ver morphology above the Chulitna River will be effectively eliminated.Although an ice cover could form up to Devil Canyon,the rapi d ri se in streamflows whi ch causes the initial ice movement at breakup will be eliminated due to the reservoir regul ati on.Instead of movi ng downri ver and formi ng ice jams,the ice will thermally degrade.When it does move,it wi 11 be ina weakened state and wi 11 not cause a significant amount of damage. Occurrences of the overtoppi ng of the gravel berms at the upstream end of sloughs will be virtually eliminated. Movement of sand and gravel bars will be minimized.Debris jams and beaver dams,which previously were washed out by high flows,will remain in Iilace,with resultant ponding. Vegetation encroachment in the sloughs and side-channels will also be evident as the high flows are reduced. Impacts at the Chul itna confl uence and downstream wi 11 be similar to those occurring during reservoir impouR4meRt. (iii)Water Quality Water Temperature •Reservoir and Outlet Water Temperature Aft~r impoundment,Wjitana reservoir will exhibit the thermal characteristics of a deep glacial lake.Deep glacial lakes commonly show temperature stratification both during winter and summer (Mathews,1956;Gilbert, 1973;Pharo and Carmack,1979,Gustavson,1975), although stratification is often relatively weak. Bradley Lake,AlaSka,(Figure E.2.89)demonstrated a weak thermocline in late July,1980,but was virtually isothermal by late September,and demonstrated a reverse thermocline during winter months (Corps of Engineers,unpublished data). The range and seasonal variation in temperature within the Watana reservoir and for a distance downstream will change after impoundment.Bolke and Waddell (1975) noted in an impoundment study that the reservoir not - only reduced thi range in temperature but also changed the timing of the high and low temperature.This will al so be the case for the Susitna Ri ver where pre-pro- ject temperatures generally range from DOC to 14°C with the lows occurri ng from October through April and the E-2-56 1 [ I f l ( [ l I [ L l l 1 ,l I I \' ( 1 I i ! I highs in July or August.However,to minimize the preproject to post-project temperature differences downstream,Watana wi 11 be operated to take advantage of the temperature stratification within the reservoir. During summer,warmer reservoir water will be withdrawn from the surface through a multi port intake structure (Figure E.2.90).The intake nearest the surface generally will be used.In this way warmer waters will be passed downstream. When water is rel eased from the epil i mni on of a deep reservoir,there is likely to be a warming effect on the stream below the dam (Turkheim,1975;Baxter and .Glaude,1980).However,given the hydrological and meteorological conditions at Watana,this may not occur. • To provide quantitative predictions of the reservoir temperature behavior and outlet temperatures,reservoir thermal studies were undertaken in 1981 and 1982.To date,detailed studies have been completed for only the open water period.A one dimensional computer model, DYRESM,was used to determine the thermal regime of the Watana reservoir and the outlet temperatures. Temperature profiles were simulated for the June through October time period using 1981 field data. Monthly reservoir temperature profi 1es and the mean daily inflow and outlet water temperatures are illustrated in Figures E.2.91 and E.2.92.The maximum .reservoir temperature simulated 'was 10.4°C and occurred in early August.This is less than the maximum recorded inflow temperature of 13°C.Although there is an initial lag in outflow temperatures in early June, it is possible to reasonably match inflow temperatures from 1ate June to.mid-September.Thus,the summer out1 et temperatures from Watana will have no impact on the downstream fishery resource. In late September the natural water temperature falls to near zero degrees.Because of the large quantity of heat stored in the reservoir,it is not possible to match these natural temperatures.The lowest outl et temperature that could be obtained is 4°C with the use of a lower level outlet. From September through November,reservoi r water tem- peratures will gradually decrease until an ice cover is developed in late November or December.During the ice cover formation process and throughout the winter,out- E-2-57 I 1 l I ! f I ( I I I ! ( I I j j I I flow temperatures will be between DOC and 4°C but,most likely the low temperature will be lOC or greater. This range of outflow temperature (lOC to 4°C)can be obtained by selectively withdrawing water of the de- sired temperature from the appropriate port within the intake structure.Thus,when the optimum temperature, between approximately lOC and 4°C,has been determined, the reservoir wi 11 be operated to match that temperature as closely as possible. >Downstream Mainstem Water Temperatures In winter,the outflow temperature will initially de- crease as reservoir heat is exchanged with the cold atmosphere.The downstream temperatures were investi- gated with a constant 4°C outflow and also with a temperature of 4°C up to October 15 and decreasi ng linearly to 1°C by January 1.This sort of analysis brackets the expected temperature regime during Watana operation.• At the downstream end of Devil Canyon,the temperatures would be in the range of 1.5°to O°C by about the first week in January.This would place the upstream edge of DOC water somewhere between Sherman and Portage Creek by about the middle of January.This regime would conti nue through the remai nder of the wi nter until about Apri 1 when the net heat exchange agai n becomes positive. During summer,outlet water temperatures will approxi- mate existing baseline water temperatures.Downstream water temperatures wi 11 essent ia lly be unchanged from existing water temperature.For example,at Gold Creek maximum June water temperatures will approximate 13°C. Through July,temperatures will vary from lDoC to 12°C and through mid-August temperatures will remain at about 1DoC.About mid-August,temperatures will begin to decrease • •Slough Water Temperatures Preliminary investigations show that ground water up- welling temperatures in sloughs reflect the long term water temperature of the Susitna Ri ver.Downstream of Devil Canyon,the long term average is not expected to change significantly. Post-project summer Sus itna Ri ver water temperatures downstream of Portage Creek will be similar to existing temperatures.Fall temperatures will be sl ightly warmer but should fall to DOC by January and wi 11 remai n at DOC unt i 1 temperatures begi n to warm.In E-2-58 [ r \ l r I l [ [ [ [ t [ l I l J .J -l I j I I ( I I I I. ( I I I I I· L spring,however,water temperatures should remain cooler longer.This will counteract the warmer fall temperatures and result in the average annual water temperature remaining close to existing conditions in the Talkeetna to Devil Canyon reach. -Ice The delayed occurrence of DoC water in the redch below Devil Canyon will tend to delay the formation of an ice cover significantly.Since 75-80%of the ice supply be- low Talkeetna is currently from the Susitna River,the formation of the cover will be delayed until about December and ice front progress i on above the conf1 uence starting in late December or early January.Depending on the water temperatures upstream,the ice cover wi 11 pro- gress to a point between Sherman and Portage Creek. Staging will range from about 4 ft at Talkeetna to about 3 ft at Sherman.The more likely occurrence is an ice cover to Portage Creek. Duri ng breakup,the cover wi 11 tend to thermally erode from both downstream and upstream.The downstream ero- sion will be similar to existing conditions while the upstream wi 11 be due to the warm water supp 1i ed by the reservoir as well as the positive net atmospheric heat exchange.Due to the lower flows,the breakup of the ice cover will be less severe than the baseline case. -Suspended Sediments As the sediment 1aden Sus itna Ri ver enters the Watana reservoir,the river velocity will decrease and the larger diameter suspended sediments will settle out to form a del ta at the upstream end of the reservoir·.The delta formation will be constantly adjusting to the changing reservoir water level.Sediment will pass through channels in the delta to be deposited over the lip of the delta.Depending on the relative densities of the reservoir water and the river water,trre river water containing the finer unsettled suspended sediments will either enter the lake as overflow (surface current), interflow,or underflow (turbidity current). Trap efficiency estimates using generalized trap effi- ciency envelope curves developed by Brune (1953)indicate 90-100 percent of the incoming sediment would be trapped in ·a reservoir the size of Watana Reservoir.However, sedimentation studies at glacial lakes indicate that the Brune curve may not be appropri ate for Watana.These studies have shown that the fine glacial sediment may pass through the reservoir.Indeed,glacial lakes i mmedi ate1y below gl aci ers have been reported to have E-2-59 E-2-60 Suspended sediment concentrations downstream will be similar to that discussed in Section 3.2(b),(iv)except that maximum particle sizes leaving the reservoir will be 3-4 microns. Slumpi ng wi 11 occur for a number of years until the valley walls attain stability.This process will cause locally increased suspended sediment and turbidity levels.Sediment suspended during this process are expected to be si lts and cl ays.Because of their small size these particles may stay in suspension for a long period of time.Nonetheless,during summer,the levels of suspended sediments and turbidity should remain on the order of five times less than during pre-project riverine conditions.If slumping occurs during winter,increases in suspended sediment concentrations over natural condi- tions will occur.Since cold ambient air temperatures during the winter will freeze the valley walls,the num- ber of slides will be reduced and impacts should be minor. Particle diameters of 3-4 microns have been estimated to be the approximate maximum size of the sediment particles that will pass through the Watana reservoir (Peratrovich, Nottingham &Drage,1982).By examining the particle size distribution curve (Figure E2.36),it is estimated that about 80 percent of the i ncomi ng sediment wi 11 be trapped. For an engineering estimate of the time it would take to fill the reservoir with sediment,a conservative assump- tion of a 100 percent trap efficiency can be made.This results in 472,500 ac-ft.of sediment being deposited after 100 years (R&M,1982d)and is equi val ent to 5 percent of total reservoir volume and 12.6 percent of the live storage.Thus,sediment deposition will not affect the operation of Watana reservoir. In the Watana reservoir,it is expected that wind mlxlng will be significant in retaining particles less than 12 mi crons in sus pens ion in the upper 50-foot water 1ayer (Peratrovich,Nottingham &Drage,1982).Re-entrainment of sediment from the shall ow depths along the reservoir boundary during high winds will result in short-term high turbidity 1evel s.Thi s wi 11 be part i cul arly important duri ng the summer refi 11 i n.g process when water 1evel s will rise,resubmerging sediment deposited along the shoreline during the previous winter drawdown period. r f l r r r l [ I [ l r l l l. Kamloops Lake, on the Thompson of the i ncomi ng trap efficiencies of 70-75 percent. British Columbia,a deep glacial lake River,retains an estimated 66 percent sediment (Pharo and Carmack,1979). I I -I I I I I r I I I I I I I I I I I ,I ,I 1 I ~ I I I I .i I J I I 1 -Turbi dity Turbidity patterns may have an impact on fisheries,both in the reservoir and downstream.Turbi dity in the top 100 feet of the reservoir is of primary interest.The turbidity pattern is a function of the thermal structure, wind"mixing and reentrainment along the reservoir boun- daries.Turbidity patterns observed within Eklutna Lake, a lake 30 miles north of Anchorage,may provide the best "available physical model of turbidity within Watana Reservoir.Although it is only one tenth the size of the W"atana Reservoir,its morphometri c characteri st ics are simi"lar to Watana.It is 7 miles long,200 feet deep, has a surface area of 3,420 acres,and has a total stor- age of about 414,000 ac-ft.Bulk annual residence time is 1.77 years,compared to Watana's 1.65 years.It also has 5.2"percent of its basin covered by glaciers,com- pared to 5.9 percent of Watana IS drai nage area.Conse- quently,it is believed that turbidity patterns in the two bodies of water will be somewhat similar. Data collected at Eklutna from March through October 1982 demonstrates the expected pattern at Watana.In March, turbi dity beneath the ice cover was uniformly 1ess than -10 NTU in the lower end of the lake near the intake to the"Eklutna hydroelectric plant.Shortly after the lee melted in late May,but before significant glacial melt had commenced,turbidity remained at 7-10 NTU throughout the water column.By mid-June,the turbidity had risen to 14-21NTU,but no distinct turbidity plume was evi- dent.It is believed the lake had recently completed its spring overturn,as a warming trend was evident only in the upper 3 meters.By early July a slight increase in turbi dity was noted at the 1ake bottom near the ri ver inlet.Distinct turbidity plumes were evident as inter- flows in the upstream end of the lake from late July through mid-September.Turbidity levels had significant- ly decreased by the time the plume had traveled 5 miles down the lake,as sediment was deposited in the lake.In late September,a turbid layer was noted on the bottom of the lake as river water entered as underflow.By mid- October,the lake was in its fall overturn period,with near-uniform temperatures and turbidity at about 7°C and 30-35 NTU,respectively. In Kamloops Lake,B.C.,thermal stratification of the 1ake tended to "s hort-circuit"the ri ver pl urnes especi a 1- ly during periods of high flow (St.John et at.~1976). The turbi d pl ume was confi ned to the surface 1ayers, resulting in a relatively short residence time of the river water during summer.St.John et ale (1976)noted that high turbidity values extended almost the entire E-2-61 I I( length of Kamloops Lake during the summer,suggesting that the effects of dilution and particle settling were minimal due to the thermocline at 10°_6°C effectively separating the high turbidity waters in the upper layers of the lake from highly transparent hypolimmion waters. This was not apparent in the Eklutna Lake data.Plumes were evident up to 5 miles down the lake,but they were below the thermocline.In addition,particle settling and dilution were evident,as turbidity continually dec~eased down the length of the lake. The relatively cool,cloudy climate in southcentral Ali;lska would tend to prevent a sharp thermocline from devel opi ng,so that"the processes evident in Kamloops Lake would not be expected in Eklutna Lake,nor will they be expected in the Watana reservoir.. -Total Dissolved Solids,Conductivity,Alkalinity, Significant Ions and Metals The leaching process,as previously identified in Section 3.2.(a)(ii),is expected to result in increased levels of the above parameters within the reservoir immediately after impoundment.The magnitude of these changes cannot "be quantified,but should not be significant (Peterson, 1982).Furthermore,Baxter and Glaude (1980)have found such effects are temporary and diminish with time. The effects wi 11 dimi ni sh for two reasons:First,the most soluable elements will dissolve into the water rather qUickly and the rate of leachate production will decrease with time.Second,much of the inorganic sedi- ment carri ed by the Susitna Ri ver wi 11 settl e in the Watana Reservoir.The formation of an inorganic sediment blanket on the reservoir bed will retard leaching (Peterson and Nichols,1982). The effects of the 1eachi ng process shoul d not be re- flected in the river below the dam since the leachate is expected to be confined to a small layer of water immedi- ately adjacent to the reservoir floor and the intake structures will be near the surface. Due to the large surface area of the proposed impound- ment,evaporati on will be substant i ally increased over existing conditions.The annual average evaporation rate for May through September at Watana is estimated at 10.0 inches or 0.3 percent of the reservoir volume (Peterson and Nichols,1982).During evaporation,slightly higher concentrations of dissolved substances have been found at the surface of impoundments (Love,1961;Symons,1969). Neglecting precipitation which would negate the effects E-2-62 I r [ f [ f I t (" [ ( [ ( [ [ l L I.J'i:.-. ! -1) J l I \ .I i\... f JL_ I I l!.o... I I \ I Il I I I I l- of evaporation,the potential increase of less than one percent is not considered significant (Peterson and Nichols,1982). Dissolved solid concentrations are expected to increase near the surface of the impoundment during ~inter. Mortimer (1941,1942)noted that the formation of ice at the reservoir surface forces dissolved solids out of the freezi ng water,ther'eby i ncreas i ng concentrations of these solids at the top 9f the reservoir.No significant impacts should result either in the reservoir or down- stream of the dam.. Precipitation of metals such as iron,manganese and other trace elements have been noticed in reservoirs resulting in reduced concentrations of these elements (Neal,1967). Oligotrophic reservoirs with high pH and high dissolved salt concentrations generally precipitate more metal than reservoirs with low pH and low dissolved salt concentra- tions.This is attributed to the dissolved salts react- ing with the metal ions and subsequently settling out (Peterson and Nichols,1982).Average Susitna River conductivity values for Vee Canyon and Gold Creek during winter are 70 and 125 umhos/cm at 25°C,respectively. For summer they are'somewhat lower,·45 umhos/cm at 25°C for both stations.Values for pH range between 7.3 and 7.6 for the two stations.Although neither of the para- meters were high,some precipitation of metals is·ex- pected to reduce the quantities suspended in the reservoir. -Di sso 1ved Oxygen Susitna River inflow will continue to have both high dis.;. solved oxygen concentrations and high percentage satura- t ions.The oxygen demand enteri ng the reservoir shaul d cont i nue to remain low.No man-made sources of oxygen demandi ng effl uent exist upstream of -the impoundment. Chemi cal oxygen demand (COD)measurements at Vee Canyon during 1980 and 1981 were quite low,averaging 16 mg/l. No biochemical oxygen demand values were recorded. Wastewater from the permanent town will not contribute an oxygen demand of any si gni fi cance to the reservoir.All wastewater wi 11 be treated to avoid effl uent related problems. The trees within the inundated area will have been cleared,removing the potential BOD they would have -created.The layer of organic matter at the reservoir bottom will still remain and could create some short term localized oxygen depletion.However,the process of decomposition should be very slow due to the cold temperatures. E-2-63 -I ! I I I ,\ j The weak strat ifi cat i on of the reservoi r may cause the oxygen levels in the hypolimnion to diminish due to lack of oxygen replenishment.The spring turnover,with its large inflow of water,will cause mixing;however,the depth to which this mixing will occur is unknown.As a result,the hypolimnion could experience reduced oxygen 1evel s.The upper 200 feet of the impoundment shoul d maintain high D.O.due to river inflow and continual mixing. Downstream of the dalJ1,no di ssol ved oxygen changes are anticipated since water will be drawn from the upper layer of the reservoir. -Nitrogen Supersaturation As previously noted,nitrogen supersaturation can occur below high-head dams due to spillage.During project operation,specially designed fixed cone valves will be used to discharge spills up to the once in fifty year flood. -Trophic Effects (Nutrients) Reservoir trophi c status is determi ned in part by the relative amounts of carbon,silicon,nitrogen and phos- phorus present in a system,as well as the quality and quantity of light penetration.The C:Si:N:P ratio indicates which nutrient level s wi 11 1imit a1 gae prOduc- tivity.The nutrient which is least abundant will be ·limiting.On this basis,it was concluded that phos- phorus will be the limiting nutrient in the Susitna impoundments.Vollenweider's (1976)model was considered to be the most reliable in determining phosphorus concen- trations at the Watana impoundment.However,because the validity of this model is based on phosphorus data from temperate,clear water lakes,predicting trophic status of silt-laden water bodies with reduced light conditions and high inorganic phosphorus levels may overestimate the actual trophic status. The spring phosphorus concentration in phosphorus limited lakes is considered the best estimate of a lake's trophic status.Sio-avai1able phosphorus is the fraction of the total phosphorus pool which control s a1 gae growth in a parti cul ar 1ake.The measured di sso 1ved orthophosphate concentration at Vee Canyon was considered to be the bio- available fraction in the Susitna River.Accordingly, the average dissolved orthophosphate concentration in June was multiplied by the average annual flow to calcu- late spring phosphorus supplies.These values were in turn combi ned with phosphorus val ues from preci pi tat;on E-2-64 l r r f' I [ r r [ [ r I [ l [ [ [ t_ L and divided by the surface area of the impoundment.The resultant spring phosphorus loading values at Watana were far below the minimum loading levels that would result in anything other than oligotrophic conditions.Likewise, upon incorporating spring loading values into Vollenweider's (1976).phosphorus model,the volumetric spring phosphorus concentration fell into the same range as oligotrophic lakes with similar mean depths,flushing rates,anrl phosphorus loading values (Peterson and Nichols,1982). -l I II I I \' \I The aforementioned trophic status several assumptions that cannot basis of existing information. i·nc1 ude: predictions depend upon be quantified on the These assumpt ions I \ i I I I I t I j I J ,\ I ) ,I Jl,•. (i V) •The C:5i :N:P ratio does not f1 uctuate to the extent that a nutri ent other than phosphorus becomes 1imit- i ng; •No appreciable amount of bio-availab1e phosphorus is released from the soil upon fill i ng of the reservoirs; •Phosphorus loading 1eve1 sare constant.throughout the peak algal growth period; •June phosphorus concentrations measured at Vee Canyon correspond to the time of peak algal productivity; •Phosphorus species other than dissolved orthophosphate are not converted to a bio-avai1ab1e form; •F1 ushi ng rates and phosphorus'sedimentat i on rates are constant; •·Phosphorus losses occur only through sedimentati on and the outlet;and •The net loss of phosphorus to sediments is proportional to the amount of phosphorus in each reservoir. Effects on Groundwater Conditions -Mainstem As a result of the annual water level fluctuation in the reservoir,there will be localized changes in groundwater in the immediate vicinity of the reservoir.Groundwater impacts downstream will be confined to the river area. E-2-65 -1 ) -) ! .'I i, \ I (v) -Impacts on Sloughs During winter,in the Talkeetna to Devil Canyon reach, some sloughs (i.e.those nearer Talkeetna)will be adja- cent to an ice covered section of the Susitna River and others will be adj acent to an ice free sect i on.In ice covered sections,the Susitna River will have staged to form the ice cover at proj ect operat i on flows of about 10,000 cfs.The associated water level will be a few feet above normal winter water levels and will cause increased upwelling i nthe sloughs because of the i n- creased gradi ent.The'berms at the head end of the sloughs may be overtopped. A number of sloughs may be.adjacent to open water sec- tions of the Susitna River.Since flows will average approximately 10,000 cfs in winter,the associated water level will be less than the existing baseline Susitna River water levels in winter because ice staging under present conditions yields a water level equivalent to an open water discharge that is greater than 20,000 cfs. Hence,it is expected that the winter gradient will be reduced and will result in a decreased upwelling rate in the sloughs. . Duirng summer,the mainstem -slough ground water inter- action will be similar to that discussed in Section 3.2 (b)(v),with the exception that operational flows will be greater than the downstream flows during filling and thus upwelling rates will be closer to the natural condition than were the upwelling rates during filling. Instream Flow Uses -Fishing Resources,Riparian Vegetation and Wildlife Habitat s Impacts of project operati on on the fi shery resources, riparian vegetation and wi1~life habitat are discussed in Chapter 3. Navigation and Transportation Within the reservoir area,water craft navigation will extend to November because of the delay in ice cover for- mation.During winter,the reservoir will be available for use by dogsled and snow machine. A1though summer flows will be reduced from natural condi- tions during project operation,navigation and transpor- tation in the Watana to Talkeetna reach will not be significantly impacted.Flows will be stabilized due to E-2-66 L r r r [ r r [ t ( I [ l l l l L [ \ I.["i' I I, I ' i JL.: I j I ) L l 1 I, ) I i L. a base-loaded operation.However,because of the reduced water levels,caution will be required in navigating various reaches.There will be less floating debris in this reach of the river,which will reduce the navigational hazards. During the fall and winter a significant reach of the river downstream of Watana will contain open water.This will allow for a longer boating season but will impede use of the river as a transportation corridor by'snow machine or dog sled. Downstream of Talkeetna,ice formation may be delayed and river stage during freezeup will be increased.This may impede winter transportation across the ice. -Estuarine Salinity Salinity changes in Cook Inlet due to project operations were projected through the use of a computer model (Resource Management Associates,1982).A comparison of the sal i nity impacts of average project flows with aver- age natural -inflow showed that under project operation, the sal i nity range decreased a maximum of two parts per thousand (ppt)near the mouth of the Susitna River.The change was most notable at the end of winter when post .project salinities were 1.5 ppt lower than existing con- ditions.At the end of September post project salinities were about 0.5 ppt higher than natural salinities because of the reduced summer freshwater inflow.Although there will be seasonal differences in salinity,the post pro- ject salinity changes should not have a significant impact. 3.3 -Devil Canyon Development (a)Watana Operation/Devil Canyon Construction Construction of the Devil Canyon site is scheduled to begin in 1995.When comp 1eted,the Devi 1 Canyon development wi 11 consi st of a 646 foot high,concrete arch dam,outlet facilities capable of passing 38,500 cfs,a f1ipbucket spi llway with a capacity of 125,000 cfs,an emergency spillway with a capacity of 160,000 cfs, and a 600 MW capacity powerhouse.Further i nformat i on on the physical features of.the Devil Canyon development can b~found in Section 7 of Exhibit A. The Devil Canyon diversion is designed for the 25 year recurrence interval flood.This is because of the degree of regulation provided by Watana. Any di fferences in the quant i ty and quality of the water from existing baseline conditons during the Devil Canyon construction will be primarily due to the presence and operation of -the Watana facility.Therefore,the impacts described in Section 3.2(c) will,in most cases,be referred to when discussing the impacts of Devil Canyon construction. (i).Flows Operation of Watana will be unchanged during the construc- tion of Devil Canyon.Hence,flows will be as discussed in Section 3.2(c).Mean monthly flows for Watana,Gold Creek, Sunshine,and Susitna Station are illustrated in Tables E.2.21,E.2.24, E.2.27,and E.2.29.Monthly flow duration curves are shown in FiguresE.2.85 through E.2.88. During construction of the diversion tunnel,the flow in the mai nstem wi 11 be'unaffected.Upon comp let i on of the diversion tunnels in 1996,the upstream cofferdam wi 11 be closed and flow diverted through t.he diversion tunnel with- out any interruption in flow.This action will dewater approximately 1,100 feet of the Susitna River between the upstream and downstream cofferdams. Because 1itt le ice wi 11 be generated through the Watana Dev i1 Canyon reach,pond i ng duri ng wi nter wi 11 be unneces- saryat Devil Canyon. Velocites through the 30 foot diameter tunnel at flows of 10,000 cfs will be 14 feet per second. The diversion tunnel is designed to pass flood flows up to the once in 25 year summer flood,routed through Watana. The flood frequency curve for Devil Canyon is illustrated in Figure E.2.93.Initially,there is little change in discharge with frequency.This is due to the fact that the E-2-68 [ [ r r r l r r [ l ( I [ [ [ [ l L L ~,L J !'-[ J I- I C f r-----,.- ll,_ if r). f-: 'I ~ I~ j L I I l, f L ![.:, 1.'_. 1 L Watana Reservoir can absorb the one in fifty year flood, discharging a maximum of 31,000 cfs (24,000 cfs through the outlet facilities and 7,000 cfs through the powerhouse [assuming minimum energy demand]). (ii)Water Quality -Water Temperatures There will be no detectable difference in water tempera- tures at Devi I Canyon or points downstream from those discussed in Section 3.2(c)(iii)Watana Operation. -Ice Ice processes will be unchanged from those discussed in Section 3.2(c)(iii)Watana Operation except that in the event water temperatures are lowered to O°C upstream of Devil Canyon,any frazil ice produced will be passed through the diversion tunnel. -Suspended Sediment/Turbidity/Vertical Illumination Consfruction of ·the Devil Canyon facility will have im- pacts simi 1ar to'those expected dur i ng the Wat an a con- struction.Increases in suspended sediments and turbid- ity are expected duri ng tunne 1 excavat i on,placement of the cofferdams,blasting,excavation of gravel from bor- row areas,gravel washing,and clearing of vegetation from the reservoir.Any impacts that occur during summer will be minimal compared to pre-Watana baseline condi- tions.However,stringent construction practices will have to be imposed during the construction of Devi 1 Canyon to prohibit suspended sediments from entering the river and negating the improved water quality,relative to suspended sed1ments,that wi II result when Watana becomes operational.During winter,slightly increased suspended sediment concentrations can be expected since particles less than 3-4 microns in diameter wi 11 probably pass through the reservoir. No impoundment of water wi 11 occur duri ng the placement and existence of the cofferdam.As a result,no settling of sediments will occur. Slightly decreased vertical illumination will occur with any increase in turbidity. -Metals Similar to Watana construction,disturbances to so;Is and rock or shore 1i nes and ri verbeds wi II increase d;sso Ived and suspended materials to the river.Although this may £-2-69 , I ) .I I ! ) ( ,! I i result in elevated metal levels within the construction area and downstream,the water qual i ty shoul d not be significantly impaired since substantial concentrations of many metals already exist in the river (Section 2.3(a)). -Petroleum Contamination Construction activities at Devil Canyon will increase the potential for contamination of the Susitna River by petroleum products.However,as per the Watana construc- tion,precautions will be taken to ensure this does not happen (Section 3.2(a)ii). -Concrete Contamination The potential for concrete contamination of the Susitna River during the construction of the Devi 1 Canyon Dam wi 11 be greater than duri ng Watana construct i on because of the 1arge volume of concrete requi red.It is est i- mated that 1.3 mi 11 ion cubi c yards of concrete wi 11 be used in the construct i on of the dam.The wastewater associ ated with the batching of the concrete could,if directly discharged into the river,seriously degrade downstream water ·quality with subsequent fish mortality. To prevent th is,the wastewater wi 11 be neutral i zed and settling ponds will be employed to allow settlement of concrete cOrltami nants pri or to the di scharge of waste- water to the river. Other Parameters No additional ground water quality impacts are expected from those di scussed for.the proposed operat ion of the Watana faci 1ity. (iii)Ground Water There wi 11 be no ground water impacts from Devi 1 Canyon construction other than in the immediate vicinity of the construction site. (iv)Impact on Lakes and Streams in Impoundment The perched lake adjacent to the Devil Canyon damsite will be impacted by construction of the saddle dam across the low area on the south bank between the emergency spillway and the main dam.The lake is just west of the downstream toe of the saddle dam and wi 11 be drained and parti ally filled during construcion of the saddle dam. (v)Instream Flow Uses The diversion tunnel and"cofferdams will block upstream fish movement at the Devil Canyon construction site. E-2-70 / L I I [ I r r [ I L [' L l L I,~:;':. I,l I --I I , I I ( I.. r (, I I [I However,the Devi 1 Canyon and Devi 1 Creek rapids,them- selves act as natural barriers to most upstream fish move- ment. Navigational impacts wi 11 be the same as during Watana operation,except that the whitewater rapids at Devil Canyon will be inaccessible because of construction activi- ties. (vi)Facilities The construct i on of the Devi 1 Canyon power project wi 11 re-quire the construction,operation and maintenance of sup- port facilities capable of providing the basic needs for a maximum population of 1,900 people·(Acres 1982).The facilities,including roads,buildings,utilities,stores, recreation facilities,etc.,will be essentially completed during the first three years (1993-1995)of the proposed nine-year construction period.The Devil Canyon con- struction camp and village will be built using components from the Watana camp.The camp and village will be located approximately 2.5 miles southwest of the Devil Canyon dam- site.The location and layout of the:camp and village facilities are presented in Plates 70, 71,and-72 of Exhibit F. -Water Supply and Wastewater Treaatment The Watana water treatment and wastewater treatment plants wi 11 be reduced in si ze and·reut i 1i zed at Devi 1 Canyon.As a resu 1t,proces ses i dent i cal to those employed at Watana will be used to process the domestic water supply and treat·the wastewater. The water intake has been designed to withdraw a maximum of 775,000'gallons/day to provide for the needs of the support communities,or less than 1 cfs (Acres 1982). Since the source of this supply is the Suistna River no impacts on flows will occur throughout the duration of the camps existence. The wastewater treatment facility will be sized to handle 500,000 gallons daily.The effluent from this secondary treatment facility will not affect the waste assimilative capacity of the ri ver.The eff1 uent wi 11 be di scharged approximately 1,000 feet downstream of the intake. Prior to the completion of the wastewater treatment faci- lity,all wastewater will be chemically treated and stored for future processing by the facility. E-2-71 (b) The applicant will obtain all the necessary permits for the water supply and waste discharge facilities. -Construction,Operation and Maintenance Similar to Watana,the construction,operation and main- tenance of,the camp and village could cause slight increases in turbidity and suspended sediments in the local drainage basins (i .e.,Cheechacko Creek and Jack Long Creek).In addition,there will be a potential for accidental spillage and leakage of petroleum contaminat- i ng groundwater and local streams and 1akes.·Through appropriate preventative techniques,these potential impacts will be minimized. Watana Operation/Devil Canyon Impoundment (i)Reservoir Filling Upon completion of the main dam to a height sufficient to allow ponding above the primary outlet facilities (eleva-' tions 930 feet and 1,050 feet),the intake gates will be partially closed to raise the upstream water level from its natural level of about 850 feet.Flow wi 11 be maintained at a minimum of 5,000 cfs at Gold Creek if this·process occurs between October and April.From May through September,the minimum environmental flows described in Section 3.2(b}will be released (See Table E.2.17). Once the level rises above the lower level discharge valves,the diversion gates will be permanently closed and flow passed through the fixed cone valves. Since the storage volume required before operation of the cone valves can commence is less than 76,000 acre feet,the filling process will require about one to four weeks.The reservoir will not be allowed to rise above 1135 feet for approximately one year,w~ile'the diversion tunnel is being plugged with concrete. When the dam is completed,an additional storage volume of one million acre feet will be required to fill the reser- voir to its normal operating elevation of 1455 feet. Filling will be accomplished as quickly as possible (cur- rently estimated to be between 5 and 8 weeks)util izing maximum powerhouse flows at Watana.During filling of Devil Canyon Reservoir,Gold Creek flows will be maintained at or above the.minimum target flows depicted in Table E.2.17. (ii)Flows Because of the two distinct filling periods,the two-stage impoundment sequence will be several years long,even E-2-72 I r 1 ( I q r [ l r I I ~ .f [ 1 l ). t ( '- \! ,.\ ( ( f.I' (i"i 1) though the actual time for filling will only be about two months long.Flows during the first stage of filling will be impacted for a short duration. Between the fi rst stage and second stage of fi 11 ing,the reservoir wi 11 not be allowed to exceed 1135 feet.Thus, the Devil Canyon reservoir will be more or less held at a constant level.Flows along the Susitna wi 11 be unchanged from those during Devi 1 Canyon construction (See Section 3.3(a)). During the second stage of filling,wherein 1,014,000 acre-feet are ~ed __to the Devi 1 Canyon reservoi r,the Watana reservoir will--"he lowered about 25 feet if filling occurs during either fall or winter.Although the flow into Devil Canyon will be approximately twice normal power flow from Watana,the impact of increased flow wi 11 be minimal in the Devi 1 Canyon-Watana reach because the two sites are close to one another. Flow downstream of Devil Canyon will be s 1i ght ly reduced during this filling process.However,the time period will be short and flows will be maintained at or above the mini- mum target flow at Gold Creek. Since actual filling times are short and since filling will 1ikely occur in fall or winter,floods are 1ikely to be important only during the time the reservoir is not allowed to increase above 1135 feet.If a flood should occur dur- ing this time,the cone valves are designed to pass the once in fifty year design flood of 38,500 cfs. Effects on Water Quality -Water Temperature The outlet water temperatures from Watana will be unchanged from those of the Watana alone scenario. Because of the rapid filling of the Devil Canyon reser- voir,there will be minimal impact on the outlet tempera- tures at Devil Canyon during both stages of filling. Between the f.i 11 i ng st ages,the 1arger surf ace are a of the reservoir will offer more opportunity for atmospheric heat exchange.However,si nce the retent i on time wi 11 on ly be in the order of.4 days,it is expected that little change in water temperature will occur from that experienced under Watana along at the Devil Canyon outlet or downstream. E-2-73 ,I -Ice An extens i ve ice cover is not expected to form on the Devil Canyon reservoir during the period wherein a pool at approximate elevation 1135 is maintained.Addition- ally,since winter temperatures downstream will not be significantly affected by the pool,ice processes down- stream of Devi 1 Canyon wi 11 remain the same as during Devil Canyon construction. Suspended Sediments/Turbidity/Vertical Illumination As previou~is~ussed,the Watana reservoir will act as a sediment trap,greatly reducing the quantity of sus- pended sediment entering the Devil Canyon reservoir. During the fi lling of Devi 1 Canyon from approximately elevation 1135 feet to full pool,the flow will be increased to the maximum power flow from Watana. Because of the reduced residence time,this could cause a slight increase in suspended sediment concentrations leaving Watana reservoir.However,Devil Canyon will provide additional settling capability and thus,the net result in suspended sediment concentration downstream of Devil Canyon will not be different from that during operation of Watana alone.Turbidity levels and vertical illumination will remain unchanged from Watana only operation. Some short-term increases in suspended sediment concen- tration and turbidity may occur within the Devil Canyon impoundment from slump i ng of vall ey wa 11 s•However, since the Devil Canyon impoundment area is characterized by a very shallow overburden 1ayer with numerous out- croppings of bedrock,slope instability should not signi- ficantly affect turbidity a~d suspended sediment concen- tration.A further discussion of slope stability can be found in Appendix K of the Susltna Hydroelectric Project Geotechnical Report (Acres 1981). -Total Dissolved Solids,Conductivity,Alkalinity, Significant Ions and Metals Similar to the process occurring during Watana filling, increases in dissolved soilds,conductivity and most of the major ions will likely result from leaching of the impoundment soils and rocks during Devil Canyon filling. However,for initial filling,from elevation 850 to 1135, no significant downstream impacts are foreseen, since it wi 11 take only about two weeks to accumulate the 76,000 acre-feet of storage.In such a short time,insignifi- cant leaching would occur which could be detrimental to downstream water quality. £-2-74 I. r :f f r 'I f'"I L f { ( [ q [ ( l L l r ( r r L I L Subsequent to initial filling and for the remainder of the filling process,fixed-cone valves will be utilized for reservoir discharge.Since they will be drawing water from wel,1 above the bottom of the impoundment and since the leaching process will be confined to a layer of water near the bottom (Peterson and Nichols,1982)down- stream water quality should not be adversely impacted. Evaporation at the Devil Canyon reservoir surface will be increased above existing riverine evaporation,but this wi 11 be negated by pre,cipitation fall ing directly on the reservoir.Hence,there will be no impact on total dis- solved solid concentration from ~or~ion. Dissolved Oxygen As previously'discussed in Section 3.2(c),(iii)Watana Operation,water entering Devil Canyon will have a high dissolved oxygen concentration and low BOD. Because of the extremely short residence times,no hypo- 1imentic oxygen depletion is expected to develop during either the one year that the reservoir is held near elevation 1135 feet or the final six weeks of reservoir filling. Treated wastewater will continue to be discharged down- streamQf the dam,but the river flow will be more than ample to assimilate any wastes. -Nitrogen Supersaturation Nitrogen supersaturation will not be a concern during the filling of Devil Canyon reservoir.During the initial fi lling to an elevation of no greater than 1135,low level outlets will be employed.No superstauration with- in the lower level of the reservoir will occur during thi s two week time frame.Further,there wi 11 be no plunging discharge to entrain nitrogen. Duri ng the remai nder of the fi 11 i ng sequence,di scharge will be via the fixed cone valves.Therefore,no nitro- gen superstauration conditions are expected downstream of the dam. Support Facilities No impacts are anticipated during the filling process as the result of the withdrawal of water and the subsequent di scharge of the treated wastewater from either the camp or vi 11 age. E-2-75 I l ) Some localized increases in suspended sediments and tur- bidity are expected to occur during the dismantling of the camp which may begin at this time.Using the appro- priate preventive procedures,any impacts should be mini- mized.. (iv)Groundwater No major groundwater impacts are anticipated during the impoundment of Dev 11 Canyon.Th e increased water 1eve 1 within the reservoir will be confined between bedrock walls.Downstream there may be a slight decrease in water level from reduced flows if fillh:t.g....oCGlJrs other than in August or the first 3 weeks of September.The associated change in groundwater level will be confined to the immediate area of the riverbank. (v)Impacts on Lakes and Streams in Impoundment As the Devi 1 Canyon poo 1 1eve 1 ri ses,the mouths of the tributaries entering the reservoir will be inundated for up to 1.6 miles (See Table E.2.11).Sediment transporated by these streams wi 11 be deposi ted at the new stream mouth established when the reservoir is filled. (vi)Instream Flow Uses -Fisheries As Devil Canyon reservoir is filled,additional fishery habitat will become available within the reservoir.How- ever,impacts to fish habitat wi 11 occur as tributary mouths become inundated.Further information on reser- voir and downstream impacts in Chapter 3. Navigation and Transportation During filling,the rapids upstream of Devil Canyon will be inundated and white water kayaking opportunities will be lost.Since the reservoir will be rising about as much as 8 feet per day during filling,the reservoir will be unsafe for boat i ng.Downstream water 1eve 1s may be slightly lowered,but this is not expected to affect navigation because of the slight change most likely con- fined to the winter season. -Waste Assimilative Capacity Although flows in the river will be reduced during the two segments of reservoir filling,the waste assimilative capacity of the river will not be affected. E-2-76 L r J I , ;~ i r [ I :r f L L ! l l (, ;;r~.J ( ( I r·, r 1 ), r-· i "[~~ '"ow", I L (c)Watana/Devil Canyon Operation (i)Flows -Project Operation When Devi 1 Canyon comes on 1i ne,Watana wi 11 be operated as a peaking plant and Devil Canyon will be baseloaded. Advantage will be taken of the reservoir storage at Devil Canyon to optimize energy production while at the same time providing the downstream flow requirements. Each September,the Watana reservoir wi 11 be fi lled tQ'-a:s --..--- near the maximum water level of 2190 feet as possible,. whi le sti 11 meeting the downstream flow requirements. From October to May the reservoir will be drawn down to approximately elevation 2080 feet,although the reservoir will be allowed to fall to a minimum reservoir level of 2065 feet duri ng dry years.In May,the spri ng runoff will begin to fill the reservoir. However,the reservoir wi 11 not be allowed to fi 11 above elevation 2185 until late August when the threat of a summer flood wi 11 have passed.If September is a wet month,the reservoir will be allowed to fill an addi- tional 5 feet to elevation 2190 because the probability. of significant flooding wi 11 have passed until the next spring. From November through the end of July,Devil Canyon will be operated at the normal maximum headpond elevation of 1455 feet to optimize power production.In August,the Devil Canyon reservoir will be allowed to fall to a mini- mum 1eve 1 of 1405 feet.In th is way,much of the August downstream flow requirement at Gold Creek can be met from water coming out of storage at Devil Canyon.This will allow most of the water entering the Watana reservoir to be stored rather than pass through the turbines and pro- duce unsalable energy.In September,the Devil Canyon reservoir will be further lowered if it is not already at its minimum elevation of 1405 feet and if the Watana reservoir is not full.When the downstream flow require- ments diminish in October,the Devi 1 Canyon reservoir will be filled to 1455 feet. -Minimum Downstream Target Flows The minimum downstream target flows at Gold Creek which controlled the summer operation of Watana alone will be unchanged when Devil Canyon comes on line.Table E.2.17 illustrates these flows (A further explanation is pro- vided in Section 3.2(c)(i)). E-2-77 Monthly Energy Simulations The monthly energy simulation program was run using the 32 years of Watana and Devi 1 Canyon synthesi zed flow data.Pre-project flow data is presented in Tables E.2.32 and E.2.33.(The development of the Watana and Devil Canyon flow sequences used in the simulation was discussed in Sections 2.1(a)and 3.2(c),(i).) Monthly maximum,minimum,and median Watana and Devil Canyon reservoir levels for the 32 year simulation are illustrated in Figures E.2.94 and E.2.95. .Daily Operation With both Devi 1 Canyon and Watana operating,Watana wi 11 operate as a peak i ng plant 5i nce it wi 11 di s- charge directly into the Devil Canyon reservoir where the flow can be regulated.Water levels in Devil Canyon wi 11 fluctuate less than one foo.t on a dai ly basi s due to the peak i ng operat i on of Watana.Devi 1 Canyon will operate as a baseloaded plant for the life of the project. -Mean Monthly and Annual Flows Monthly Watana,Devil Canyon and Gold Creek flows for the 32 year monthly energy simulation are presented in Tables E.2.34,E.2.35,and E.2.36.The maximum,mean,and mini- mum flows for each month are summari zed and compared to pre-project flows and Watana only post-project flows (where appropriate)in Tables E.2.22,E.2.37,and E.2.25. From October through Apri 1,the post-project flows are many times greater than the natural,unregulated flows. Post-project flows during the month~of June,July, August,and September are 36,34,56,and 79 percent of the average mean monthly pre-project flow at Gold Creek respectively.The reductions represent the flow volume used to fill the Watana reservoir.Variations in mean monthly post-project flows occur·but the range is substantially reduced from pre-project flows. Further downstream,percentage di fferences between pre- and post-project flows are reduced by tributary inflows. The pre-and post-project monthly flow summaries for Sunshine and Susitna Station are compared in Tables E.2.30 and E.2.31.Monthly post-project flows are presented in Tables E.2.38 and E.2.39.Although summer flows from May through October average about 8 percent less at Susitna station,winter flows are about 100 percent greater than existing conditions. E-2-78 ! f I I ,e\. I --....- r- l r t --l ·r..... [ r L I I ( l t I I' \. J ( I j \<-. \ ( ( I A comparison of post-project mean monthly flows with Watana operating alone,and with Watana and Devi 1 Canyon both operating shows that although there are some differ- ences,the differences are minor. -Floods .Spring Floods For the 32 years simulated,.,lo flow releases occurred between May and July at either Watana or Devil Canyon. All flow was either absorbed in the Watana reservoir or passed through the respective powerhouses.The June 7, 1964 flood of record with an annual flood recurrence interval of better than 20 years,resulted in a Watana reservoir elevation of 2151 feet at the end of June,an elevation well below the'elevation at which flow is released. The maximum mean monthly discharge at Devil Canyon dur- ing the spring flood period was approximately 10,500 cfs.If peak inflow into Dev i 1 Canyon reservoi r con- tributed from the drainage area downstream of Watana approached thi s di scharge,flow at Watana would be virtually shut off to maintain a Devil Canyon reservoir level of 1455 feet.Lateral inflow would supply most of the power needs.However,it is unlikely the peak contribution downstream of Watana wQuld be as large as 10,500 cfs.For'example,the Gold Creek maximum his- torical one day peak flow to mean monthly flow ratio for the month of June is 2.05.If it is assumed this is valid for the d~ainage area between Watana and Devil Canyon,the-peak-1 day June inflow during the simu- lation period would approximate 9300 cfs. For the once in fifty year flood,the downstream flow with both Watana and Devil Canyon in operation will be similar to the flow with Watana operating alone.The' Watana reservoir wi 11 be drawn down sufficiently such that the once-in-fifty-year flood volume can be stored within the reservoir if the flood occurs in June.The flow contribution at Devil Canyon for the drainage area between Watana and Devil Canyon would approximate 11,000 cfs.Hence,power needs would be met by running Devil Canyon to near capacity and reducing outflow from Watana as much as possible to prevent flow wastage. For flood events greater than the once in fifty year event and after Watana reservoir elevation reaches 2185.5,the powerhouse and outlet facilities at both Watana and Devi 1 Canyon wi 11 be operated to match inflow up to the full operating capacity of the power- house and outlet facilities.If inflow to the Watana reservoi r conti nues to be greater than outflow,the E-2-79 I ( ( -i ( ( j 0 \ I ( ( ( \ reservoir will gradually rise to elevation 2193.When the reservoir level reaches 2193,the maln spi llway gates wi 11 be opened and operated so that outflow matches i nfl ow.Concurrent with openi ng the Watana main spi llway gates,the main spi llway gates at Devi 1 Canyon will be opened such that inflow matches outflow. The main spillways at both Watana and Devil Canyon will -have suffi ci ent capacity to pass the one in 10,000 year _event.Peaki nflow for the one in 10,000 year flood will exceed outflow capacity at Watana resulting in a slight increase above 2193 feet.At Devil Canyon there wi 11 be no increase in water 1eve 1.The di s- charges and water levels associ ated with a once in 10,000 year flood for both Watana and Devil Canyon are illustrated in Figures £.2.83 and £.2.96. If the probable maximum flood (PMF)were to occur,the -operation at Watana would be unchanged whether Watana is operating alone or in series with Devil Canyon.The mai n spi llway wi 11 be operated to match i nfl ow unt i1 the capacity of the spi llway is exceeded.At thi s point,the reservoir elevation would rise until it reached elevation 2200.If the water level exceeds elevation 2200,the erodible dike in the emergency spi llway would be washed out and flow would be passed through the emergency spi llway.The resulting total outflow through all discharge structures would be 311,000 cfs,15,000 cfs less than the PMF. At Devi 1 Canyon a simi lar scenario would occur.The main spi llway would continue to operate,passing the mai n spi llway di scharge from Watana.Once the emer- gency spi llway at Watana started operat i ng,the Devi 1 CanyOn reservoir would surcharge to 1465 and its emer- gency spi llway would begin to operate.Peak outflow would occur immediately after the fuse plug eroded away.However,the peak is slightly less than the peak inflow.The inflow and outflow hydrographs for both the Watana and Devi 1 Canyon PMF are shown in Fi gures £.2.83 and £.2.96,respectively. .Summer Floods Although there were no flow releases at the Watana site d uri ng August or September in the 32 year s i mu 1at ion, in wet years Watana and Devi 1 Canyon may produce more energy than can be used.If this occurs,flow wi 11 have to be released through the outlet facilities. However,on a mean monthly basis,the total discharge at Watana will be less than the Watana powerhouse flow capacity of 19,400 cfs.Flow wi 11 only be released when the reservoir exceeds elevation 2185.5 feet. E-2-80 L I 1 r f r [ l r [ ( ( [ ( .[ l L Since Watana was designed to pass the once in fifty year summer flood without requiring operation of the main spillway and since the capacity of the powerhouse and.outlet faci 1ities is 31,000 cfs,Watana summer flood flows wi 11 vary from a low value equal to the powerhouse flows up to 31,000 cfs for floods wi th a recurrence interval less than fifty years. For the once-i n-fi fty-year summer flood,the Watana discharge will be maintained at 31,000 cfs but the reservoir will s~rcharge to 2193 feet (refer to Section 3.2(c)(i)for the derivation of the once-in-fifty-year summer flood hydrograph). At Devil Canyon,design consideration were also estab- 1i shed to ensure that the Devi 1 Canyon powerhouse and outlet facilities will have sufficient capacity to pass the once in fifty year summer flood of 39,000 cfs with- out operating the main spillway as the resultant nitro- gen supersaturation could be detrimented to downstream fisheries.This flood is passed through the Devil Canyon reservoir without any change in water level.It includes the 31,000 cfs inflow from the once in fifty year summer flood routed through Watana plus a lateral inflow of 8000 cfs.The lateral inflow of 8000 cfs was obtained by subtracting the once-in-fifty-year Watana natural flood peak from the once-in-fifty-year Devi 1 Canyon natural flood peak. In the 32 year simulation period there were four years in which flow releases occurred during high summer flow periods.Although the maximum monthly release was only 4100 cfs,the peak flow may vary well have been higher depending on the variability of the tributary inflow downstream of Watana and on the Watana reservoir level.However,the peak Devil Canyon outflow would not have exceeded the capaci ty of the powerhouse and outlet facilities. -Flow Variability As discussed above,at both Watana and Devil Canyon,peak monthly flows may differ from mean monthly flows if the reservoir exceeds elevation 2185.5 at Watana and flow is released.For Devi 1 Canyon,as reservoir inflow from sources other than the Watana Reservoir varies,the peak outflow may also differ from the mean monthly flow. For the 32 years of simulation,the maximum Devil Canyon discharge in August was 17,900 cfs which included 14,100 cfs from Watana and 3800 cfs from tributary inflow into the Devil Canyon reservoir.In examining flow ratios of E-2-81 one day peaks to mean monthly flow at Gold Creek for the month of August it can be seen that these rat i os vary from 1.10 to 2.40.If these ratios can be applied to the tributary inflow,then the peak inflow could have been as high as 9100 cfs.Also,if the Watana powerhouse flow was not constant for the month,then some flow varia- bility could also be attributed to Watana.The net result is a Devil Canyon outflow that could be a constant value for the entire month or a variable outflow that has the same mean value but a peak on the order of 30,000 cfs.The actual variability would depend on the daily inflow hydrograph for Devil Canyon. The month 1y and annual flow duration curves for pre- project and post-project conditions for the 32 year simu- lation period are illustrated in Figures E.2.97 through E.2.I00 for Watana,Gold Creek,Sunshine,and Susitna Station.The flow duration curves show less variability during post-project operations and a diminished pre-ana post-project difference with distance downstream of Devil Canyon. {ii}Effects on Wat~r Quality -Water Temperatures The winter time temperatures discharged from Devil Canyon wi 11 range from about 4°C to laC.The temperature wi 11 slowly decrease in the downstream direction because of heat exchange wi th the colder atmosphere.In January by the time the flow reaches Sherman,a drop in temperature of about 1.3°C will be expected while a drop of about 4°C wi 11 occur to Ta 1keetna.Dependi n9 on the outflow tem- perature,the threshhold of O°C water wi 11 vary from Talkeetna to Sherman.Throughout the winter water tem- peratures upstream of Sherman.wi 11 always be above freezing,approaching the outflow temperature as it moves upstream.The minimum temperature expected at Gold Creek will be between O.SoC and 3°C. E-2-82 f I f { r r l l I I I t 1 t 1 1 l I_J The summer time temperatures will be slightly higher than those for the Watana because of the 1arger surface area for heat exchange.A pe~k temperature of about 13°C will be reached at Gold Creek about the middle of June. Through July and the first half of August,the temper- atures will ab about 10 to 12°C,slowly decreasing through the latter part of August to the end of September. -Ice The initiation of ice formation at Talkeetna will be delayed by several months.The large volume of warm water from upstream will delay and reduce the quantity of ice supplied from the Upper Susitna River.Depending on the reservoir outflow temperatures,the ice cover wi 11 start to form by the end of January and progress a short distance upstream through February.The location of the ice front is expected to be between Talkeetna and Sherman.Staging due to the ice cover will be about 3-4 feet. The breakup in the spri ng wi 11 occur downstream due to warmer climatic conditions and also from the upstream front because of the warmer water from the project.The cover will tend to thermally decay in place.Therefore, the intensity of the breakup should be less severe with .fewer ice jams than the preproject occurances. -Suspended Sediment s/Turbi dity/Vert i ~a 1 III umi nat i on Of the suspended sediments passing through.the Watana reservoir,only a small percentage is expected to settle in the Devil Canyon reservoir.This is attributable to the small sizes of the particles (less than 3-4 microns in diameter)entering the reservoir and the relatively short retention ~time.The suspended sediment,turbidity, and vertical illumination levels that occur within the impoundment and downstream wil be on ly s lfght 1y reduced from that which exists at the outflow from Watana. Some minor slumping of the reservoir walls and resuspen- si on of shore 1i ne sediment wi 11 probab 1y cont i nue to occur,especially during August and September when the reservoi r may be drawn down as much as 50 feet.These processes will produce short term,localized increases in suspended sediments.However,as previously noted,the overburden layer is shallow so no significant problems will arise.Additionally,since most of this sediment will settle out,downstream increases will be minor. E-2-83 l ( l ( ( \ i i l i \ 1 j J \ \ ( I l -Total Dissolved SOlids,lConductivity,Alkalinity, Significant Ions and Metals As previously identified in Section 3.3(b)(iii)the leaching process is expected to result in increased 1eve 1s of the aforement i oned water qual i ty propert i es. These effects are not expected to diminish as rapidly as was indicated for Watana.Although leaching of the more soluab1e chemicals will diminish,others will continue to be leached because large quantities of inorganic sediment will not be covering the reservoir bottom.It is,how- ever,anticipated that the leachate will be confined to a layer of water near the impoundment floor and should not degrade the remai nder of the reservoi r or downstream water quality. As was the case at Watana,the increased surface area will lead to an increase in the amount of evaporation. However,because of the 2.0 month retention time and the mixing actions of the winds and waves,the concentrations of dissolved substances should virtually be.unchanged and no adverse affect on water quality within the reservoir or downstream should occur. Since no ice Cover is anticipated,no increased concen- trations of dissolved solids will result at the ice-water interface. -Dissolved Oxygen As was previously discussed in Section 3.2 (c)(iii), reduction of dissolved oxygen concentrations can occur in the hypolimnion of deep reservoirs. Stratification and the slow biochemical decomposition of organic matter wi 11 promote low oxygen levels near the reservoir bottom over time.No estimates of the extent of oxygen depletion are available. Within the upper layers (epilimnion)of the reservoir, dissolved oxygen concentrations will remain high.Inflow water to the impoundment wi 11 continue to have a high dissolved oxygen content and low BOD.Since water for energy generation is drawn from the upper layers of the reservoir,no adverse effects to downstream oxygen levels wi 11 occur. -Nitrogen Supersaturation No supersaturated conditions will occur downstream of the Devil Canyon Dam.Fixed-cone valves will be employed to minimize potential nitrogen supersaturation problems for all floods with a recurrence interval less than one in fifty years. E-2-84 I f [ I f r f l r I [ i 1 1 t L L ( 1 'l l 1 '\ r r 1 J r '( )- 1 J II. 1 j 1- l. For flood flows greater than.once in fifty year flood when spillage will unavoidably occur,nitrogen super- 'saturation will be minimized through the insta~lation of spillage deflectors which will prevent the creation of a plunging action that could entrain air. - .Fac i 1it i es The construction camp and village will be decommissioned upon completion of construction and filling.Localized increases in turbidity and suspended sediments will occur in the local drainage basins due to these activities,but these effects will not be significant as erosion control measures will be employed.. (iii)Effects on Groundwater Conditions Effects on ground water conditions will be confined to the Devil Canyon reservoir itself.Downstream flows and hence impacts wi 11 be similar to those occurring with Watana operating alone. (iv)Impact on Lakes and Streams All the effects identified in Section 3.2(c)(i i)for the streams in·the Watana reservoir will be experienced by the streamsflowi ng into the Devi 1 Canyon reservoi r 1i sted in Table E.2.11.No lakes in the Devil Canyon impoundment will be impacted other than the previously described small 1ake at the Devi 1 Canyon damsi teo The tri butari es down- stream of Devil Canyon will not change from the conditions established when Watana was operating alone as discussed ear 1i er. (v)-Instream Flow Uses The effects on the fishery,wildlife habitat,and riparian vegetation are described in Chapter 3. -Navigation and Transporation The Devil Canyon reservoir will transform the heavy whitewater upstream of the dam into flat water.This wi 11 afford recreat i ona 1 opportuni ties for 1ess experi- enced boaters but totally eliminate the whitewater kayak- ing opportunities. E-2-85 t I I I I -I I I I ! \ i I J I ! ( I ) Si nce the Devi 1 Canyon faci 1i ty wi 11 be operated as a base loaded plant,downstream impacts should remain simi- ·lar to the Watana only operation.The reach of river that remains free of ice may be extended somewhat further downstream. -Estuarine Salinity Salinity variations in Cook tnlet were co,nputed using a numerical model of Cook Inlet (Resource Ma~agement Asso- ci ates,1982).As expected,the sal inity changes from baseline conditions were almost identical with those determined for Watana operation alone.The post-project salinity range is reduced,there being lower salinities in winter and higher salinity in summer.Figure E.3.101 illustrates the comparison of annual salinity variation off the mouth of the Susitna Ri ver using mean monthly pre-and post-project Susitna Station flows. 3.4 Access Plan Impacts The Watana access route wi 11 begin with the construction of a 2-mi le road from the Alaska Railroad·at Cantwell,to the junction of the George Parks and Denali Highways.Access will then follow the existing Dena 1i Hi ghway for twenty-one mi 1es.Port ions of thi s road segment wi 11 be upgraded to meet standards necessary for the ant i ci pated con- struction traffic.From the Denali Highway,a 42 mile road will be constructed in a southerly direction to the Watana site. Access to the Devil Canyon site will be via a 37 mile road from Watana, north of the Susitna Riv~r,and a 12 mile railroad extension from Gold Creek,on the south side of the Susitna River.For a more detailed description of the access routes refer to Exhibit A,Section 1.12 and 7.12. (a)Flows Flow rates'on streams crossed by the access road wi 11 not be impacted.However,localized impacts on water levels and flow velocities could occur if crossings are poorly designed.Because they do not restrict streamflow,bridge crossings are preferred to culverts or low-water crossings.Bridge supports should be located outside active channels,if possible. Where not properly designed,culverts can restrict fish movement due to high velocities or perching of the culvert above the streambed.Culverts are also more susceptible to icing problems, causing restricted drainage,especially during winter snowmelt periods. E-2-86 L r ! f r f I 'l F·.·..I' [ [ I 1 f t L L 1.. I I I I f r f I r r r I I J j J I. t. Low-water crossings may be used in areas of infrequent,.light traffic.They should conform to the local streambed slope and are to be constructed of materials so that water will flow over them instead of percolating through them,which would also restrict fi sh passage. (b)Water Quality Most water qual ity impacts associ ated with the proposed access routes will occur during construction.The principal anticipated water qual i ty impacts associ ated wi th construct i on wi 11 be i n- creased suspended sediment and turbidity levels and accidental leakage and spillage of petroleum products.Given proper design and construction techniques,few water quality impacts are antici- pated from the subsequent use and maintenance of these facili- ties. (i)Turbidity and Sedimentation Some of the more apparent potential sources of turbidity and sedimentation problems include: -Instream operation of heavy equipment; Placement and types of permanent stream crossings· (culverts ~s.bridgesY; -Location of borrow areas; Lateral stream transits; -Vegetative clearing; -Side hill cuts; -Disturbances to permafrost;and -Timing and schedules for construction. These potent ia1 sources of turbi dity and sedi ment at i on are discussed more fully in Chapter 3. (ii)Contamination by Petroleum Products Contamination of water courses from accidental spills of hazardous materials,namely fuels and oils,is a major con- cern.During construction of the trans-Alaska oil pipeline, it became apparent that oil spills of various sorts were a greater problem than anticipated.Most spills occurred as a result of equipment repair,refueling and vehicle accidents. When equipment with leaky hydraulic hoses are operated in streams petroleum products are very likely to reach the water.To avoid tt.lis,vehicles and equipment will be prop- erly maintained. Water pumping for dust control,gravel processing,dewater- ing,and other purposes can also lead to petroleum spills if proper care is not taken.Si nce water pumps are usually placed on river or lake banks very near the water,poor refueling practices could result in frequent oil spills into the water. E-2-87 i I I I I -I I i ) I I .I I ) ) I i J j 3.5 Transmission Corridor Impacts The transmission line can be div·ided into 4 segments:central (Watana to Gold Creek),intertie (Wilow to Healy),northern (Healy to Ester), and southern (Willow to Anchorage). The central segment is composed of two sect ions:Watana to Cheechako Creek and Cheechako Creek to Gold Creek.Construction of the portion from the Watana damsite to Cheechako Creek wi 11 be undertaken duri ng winter with minimal disturbance to vegetation.Hence,impact on stream flow and water quality should be minimal.From Cheechako Creek to the intertie,the transmission corridor will follow the existing trail. This should also result in minimal impacts. The Willow-Healy intertie is being built as a separate project and will be comp letedi n 1984 (Commonwealth Associ ates,1982).The Susitna pro- ject will add another line of towers within the same right-of-way.The impacts,then,will be similar to those experienced during intertie construction.The existing access points and construction trails will be utilized.The Environmental Assessment Report for the intertie (Commonwealth Associates,1982)discusses the expected environmental impacts of transmission line construction in this segment. For construction of the north and south stubs,stream crossings wi 11 .be required.The potential effects will be of the same type as those dis- cussed in Section 3.4,although generally much less severe because of the limited access needed to construct a transmission line.Erosion related problems can be caused by stream crossings vegetative clearing, siting of transmission towers,locations and methods of access,and disturbances to the permafrost.However,given proper-design and con- struction practices,few erosion related problems are anticipated • Contamination of local waters from accidental spills of fuels and oils is another potential water quality impact.To minimize this potential, vehicles will be properly maintained and appropriate refueling prac;. tices will be required. Once the transmission line has been built,there should be very few impacts associated with routine inspection and maintenance of towers and .1 i nes. Some localized temporary sedimentation and turbidity problems could occur when maintenance vehicles arerequi red to cross wetlands and streams to repair damaged lines or towers.Permanent roads will not be built in conjunction with transmission lines.Rather,grasses and shrubs will be allowed to grow along the transmission corridor but will be kept trimmed so that vehicles are able to follow the right-of-way associated with the lines.Streams may need to be forded,sometimes repeatedly,in order to effect repairs.Depending on the season, crossing location,type and frequency of vehicle traffic,this could cause erosion downstream reaches. E-2-88 j I t I I ) 1 I I I I I \ I I I I I I I I I I ! I I I 4 -AGENCY CONCERNS AND RECOMMENDATIONS Throughout the past three years,state and federal resource agencies have been consulted.Numerous water quantity and quality concerns were raised.The issues identified have been emp"hasized in this report. Some of the major topics include: -Flow regimes during filling and operation; -Reservoir and downstream thermal regime; -Sedimentation process in the reservoir and downstream suspended sedi- ment levels and turbidity; -Nitrogen supersaturation downstream of the dams; -Winter ice regime; -Trophic status of the reservoirs; -Dissolved oxygen levels in the reservoir and downstream; -Downstream ground water and water table impacts; -Effects on instream flow uses; -Sediment and turbidity increases during construction; -Potential contamination from accidental petroleum spills and leak- age;and -Wastewater discharge from the temporary community. A thorough and comp I ete comp I iment of agency concerns and recommenda- tions will be presented pursuant to the review of this drat"t license app 1i cat i on • E-2-89 I I I -i 5 -MITIGATION,ENHANCEMENT,AND PROTECTIVE MEASURES 5.1 -Introduction Mitigation measures were developed to protect,maintain,or enhance the the water quality and quantity of the Susitna River.These measures were developed primarily to avoid or minimize impacts to aquatic habi- tats,but they will also have a beneficial effect on other instream flow uses.. The first phase of the mitigation process identified water quality and quantity impacts from construction,filling and operation,and incor- porated mitigative measures in the preconstruction planning,design, and scheduling.Three key mitigation measures were incorporated into the engineering design:(1)Minimum flow requirements were selected during the salmon spawning season that were greater than what would be discharged if flow was selected solely from an optimum economic point of view.(2)A multilevel intake was added to improve temperature con- trol and minimize project effects.(3)Fixed-cone valves were incor- porated to prevent nitrogen supersaturati on from occurri ng more fre- quently than once in fifty years.Other mitigation measures incor- porated in the project design and construction procedures are discussed below. The second phase of the mitigation process will be the implementation of environmentally sound construction practices during the construction planning process.This will involve the education of project personnel to the proper techniques needed to minimize impacts to aquat.ic habi- tats.Monitoring of construction practices will be required to identi- fy and correct construction related problems.Upon completion of con- struction t the third phase of mitigation consists of operational monitoring ana surveillance to identify problems and employ corrective measures. 5.2 -Construction The mitigation,enhancement,and protective measures included in Chapter 3.2.4(a)are appropri ate for constructi on of the Watana and Devil Canyon facilities;the access road construction;and the transmission line construction. 5.3 -Mitigation of Watana Impoundment Impacts The primary concerns duri ng fi 11 i ng of the reservoir di scussed in Section 3 of this chapter include: -Maintenance of minimum downstream flows; -Maintenance of an acceptable downstream thermal regime throughout the year ;~ -Changes in downstream sediment Joads,deposition and flushing; E-2-90 I r [ ! r- \ r l [' [ 1 F i L ( ( [ I I" I I .1 I I I -Downstream gas supersaturation; -Eutrophication processes and trophic status;and -Effects on ground water levels and ground water upwelling rates. Minimum downstream flows,will be provided to mitigate the impact the filling of the reservoir could have on downstream fish and other instream flow uses.Although access may be difficult,the 12,000 cfs flow at Gold Creek in August will provide spawning salmon access to most of the sloughs between Devil Canyon and Talkeetna.Additionally, the selected downstream flow of 12,000 cfs will assist in maintaining adequate ground water levels and upwelling rates in the sloughs. Eutrophication was determined not be a problem and therefore no mitiga- tion is required. Downstream gas supersaturation will be prevented by the design of the energy disipating valves and chambers incorporated in the emergency release outlet. Changes in the downstream river morphology will occur but are not expected to be significant enough to warrant mitigation except for the mouth of some tributaries between Devil 'Canyon and Talkeetna where selective reshaping of the mouth may be required to insure salmon access. From the first winter of filling to the commencement of project opera- tion,the water temperature at the Watana low level outlet will approx- imate 4°C to 5°C.Although these temperatures will be moderated some- what downstream,downstream impacts are likely to occur.No mitigation measures have been incorporated in the desi gn to offset these low downstream temperatures during the second and third year of the filling process.If during the final de~ign phase of the project a technically acceptabl e cost-effecti ve method can be developed to mitigate thi s potential temperature impact,it will be incorporated into the final designs. 5.4 -Mitigation of Watana Operation Impacts The primary concerns during Watana operation are identified in Section 5.3. (a)Flows The minimum downstream flows at Gold Creek will be unchanged from those provided during impoundment from May through September. However,for October through April,the minimum flow at Gold Creek will be increased to 5000 cfs. These mininum flows are not the most attractive from a project econ.omic point of view.However,they do provide a base flow of sufficient magnitude that permits the development of mitigation E-2-91 measures to substantially reduce the project l s impact on the downstream fishery.Hence,the minimum downstream flows will provide a bal ance between power generation and downstream flow requirements. To provide stable flows downstream and minimize the potential for I I down stream ice jams,Watana when it is operating alone wi 11 be operated pr-imarily as a base loaded pl ant,even though it would be desirable to operate Watana as a peaking plant. (b)Temperature and D.O. I f I / ( ! I -) As noted in Section 3,the impoundment of the Watana reservoir wi 11 change the downstream temperature regime of the Susitna River. Multilevel intakes have been incorporated in the power pl ant intake structures so that water can be drawn from various depths (usually the surface).By se 1ect ivel y wi thdrawi ng water,the desired temperature can be maintained at the powerhouse tailrace and downstream.Using a reservoir temperature model,it was possible to closely match existing Susitna River water temperatures except for periods in spring and fall. (c)Nitrogen Supersaturation Nitrogen supersaturation is avoided by the inclusion of fixed-cone valves in the outlet facilities.Fixed-cone valves have been proven effective in preventing nitrogen supersaturation (Ecological Analysts Inc.1982).Instead of passing water over the spillway into a plunge pool,excess water is released through the valves.These facilities are designed to pass a once in fifty year flood event without creating supersaturated water conditions downstream. The Watana facil ities incorporate six fixed-cone valves that are capable of passing a total design flow of 24,000 cfs. 5.5 -Mitigation of Devil Canyon Impoundment Impacts Other than the continuance of the downstream flows at Gold Creek establ ished during the operation of Watana no additional mitigation measures are planned during the Devil Canyon impoundment period. 5.6 -.Mitigation of Devil Canyon/Watana Operation (a)Flows The downstream flow requirement at Gold Creek will be the same as for Watana operation alone.After Devil Canyon is on line,Watana will be operated as a peaking plant since the discharge feeds directly into the Devil Canyon reservoir.The Devil Canyon reservoir will provide the flow regul ation required to stabil ize the downstream flows. E-2-92 1 1 r r r L L l I [ I l L (b)Temperature I.,J I i I I \ -l I I f As with Watana,mult il evel intakes will be incorporated into the Devil Canyon design.Two intake ports will be needed because of the 1 im ited drawdown at Dev il Canyon. (c)Nitrogen Supersaturation The Devil Canyon Dam is designed with seven fixed-cone valves, three with a diameter of 90 inches and four more with a diameter of 102 inches.Total design capacity of the seven valves will be 38,500 cfs. E-2-93 -I J i ~ BI BLI OGRPAHY Acres American Incorporated.1982b.Susitna Hydroelectric Project - Design Development Studies (Final Draft),Volume 5,Appendix B, prepared for the Alaska Power Authority. Acres Ameri can Incorporated.1982a.Susitna Hydroe 1ectri c Project Feasibility Report:Hydrological Studies,Volume 4.Appendix A, prepared for the Alaska Power Authority. ADEC.1978.Inventory of Water Pollution Sources and Management Actions -Maps and Tables,Alaska Department of Environmental Conservation,Division of Water Programs,Juneau,Alaska. ADEC.1979.Water Quality Standards,Al aska Department of Environmental Conservation,Juneau,Alaska. ADF&G,1981.Susitna Hydroelectric Project'-Final Draft Report - Aquatic Habitat and Instream Flow Project,prepared for Acres American Incorporated. ADF&G,1982.Susitna Hydroelectric Project -Final Draft Report - Aquati c Studi es Program,prepared for Acres Ameri can Incorporated. Baxter,R.M.and P.Glaude,1980.Environmental Effects of Dams and Impoundments'in Canada:Experi ence and Prospects,Canadi an Bulletin of Fisheries and Aquatic Sciences,Bulletin 205, Department of Fisheries and Oceans,Ottawa,Canada. Bulke E.l.and K.M.Waddell,1975.Chemical Qual ity-and Temperature in Flaming Gorge Reservoir',Wyoming and Utah,and the Effect of the Reservoir on the Green River.U.S.Geological Survey,Water Supply paper 2039-A. Bruce,G.M.,1953.Trap Efficiency of Reservoirs,Trans.Am.Geophys. Union,U.S.Department of Agriculture,Misc.ubl.970 Bryan,ML.L,1974.Sublacustrine Morphology and Deposition,Klhane Lake,Yukon Territory.Pages 171-187 in V.C.Bushnell,and M.B. Marcus,eds.Ice Rield Ranges Research Project Scientific Results, Vol.4. Dwight,L.P.,1981.Susitna Hydroelectric Project,Review of Existing Water Rights in the Susitna River Basin,prepared for Acres American Incorporated,December. EPA,1976.Quality Criteria for Water,U.S.Environmental Protection Agency,Washington,D.C~ { r f ( i ( I f I I I I 1 I -I \II I· I 'I /.. I / 1_\ \ I[ ) I· I i,- EPA.1980.Water Quality Criteria Documents:Availability,Environ- mental Protection Agency,Federal Register,45,79318-79379, November. Flint,R.,1982.ADEC,Personal Communication,October. Freethy,R~D.and D.R.Scully,1980.Water Resources of the Cook Inlet Basin,Alaska,USGS,Hydrological Investigations Atlas,MA-620. Gilbert,R.,1973.Processes of Underflow and Sedilnent Transport in a British Columbia Mountain Lake.Proceedings of the 9th Hydrology Symposium,University of Alberta,Edmonton,Canada. Gustavson,T.C.,Bathymetry and Sediment Distribution in Proglacial Malcspina Lake,Alaska,Journal of Sedimentary Petrology,45:450- 461. Hydro-North,1972.Contingency Plan Study Paxson -Summit Lakes Area Trans-Alaska Pipeline,prepared for Alaska Pipeline Alyeska ~ipe line Service Co.,prepared for Alyeska Pipeline Service Company. Koenings,J.P.and G.B.Kyle,1982.Limnology and Fisheries Investiga- tions at Crescent Lake (1979-1982,Part I:Crescent Lake Limnology Data Summary,Alaska Department of Fish and Game, Soldotna,Alaska.. LeBeau,J.1982.ADEC,Personal Communication,October. Love,K.S,1961.Relationship of Impoundment to Water Quality,JAWWA, Volume 53. Matthews,W.H.1956.Physical Limnology and Sedimentation in a Glacial Lake,Bulletin of the Geological Society of America,67:537-552. McNeely,R.N.,V.P.Neimanism and K.Dwyer,1979.Water Quality Sourcebook --A Guide to Water Qual ity Parameters,Environment Canada,Inland Waters Directorate,Water Quality Branch,Ottawa, Canada. Mortimer,C.H.,1941.The Exchange of Dissolved Substances Between Mud and Water in Lakes,Parts 1 and 2,Journal of Ecology,Volume 29. Mortimer,C.H.,1942.The Exchange of Dissolved Substances Between Mud and Water in Lakes,Parts 3 and 4,Journal of Ecology,Volume 30. Neal,J.K.,1967.Reservoir Eutrophication and Dystrophication Follow- ing Impoundment,Reservoir Fish Resources Symposium,Georgia Uni vers i ty,Athens. Peratrovich,Nottingham and Drage,Inc.,1982.Susitna Reservoir Sedimentation and Water Clarity Study (Draft),prepared for Acres American Incorporated,October. '...f ) i/ I ] i Peterson~L.A.and G.Nichols~1982.Water Quality Effects Resulting from Impoundment of the Sus itna Ri ver ~prepared for R&M Consultants~Inc.~October. Phaso~C.M.~and E.D.Carmack~1979.Sedimentation Processes in a Short Residence -Time Intermontane Lake~Kamloops lake,British Colubmia,Sedimentology,26:523-541. Resource Management Associ ates,1982. Sa 1in i ty Mode 1,prepared for October. Sus itna Hydroel ectri c Project Acres American Incorporated, ·1, I R&M Consultants,Inc.,1982c.Susitna Hydroelectric Project,Hydraulic and Ice Studies,prepared for Acres American Incorporated,March. R&M Consul tants,Inc.,1982d.Sus itna Hydroel ectri c Project,Ice Observations 1980-81,prepared for Acres American Incorporated, August. R&M Consultants,Inc.1982e.Unpublished Susitna River Hydroelectric Project Data. [ f r R&M Consultants,Inc.1982f.Sus itna Hydroel ectric Project Slough Hydrology Preliminary Report,prepared for Acres American Incor- porated,October. Schmidt,D.,ADF&G,1982.Personal Communicatiori,October. R&M Consultants,Inc.1982a.Susitna Hydroelectric Project River Morphology,prepared for Acres American Incorporated,January. R&M Consultants,Inc.1982d.Susitna Hydroelectric Project,Reservoir Sedimentation,prepared for Acres American Incorporated,January. R&M Consultants,Inc.1982b.Susitna Hydroelectric Project Water Quality Interpretation 1981,prepared for Acres American Incor- porated,February. l [ [ [ l 1 l l I l Personal Communication~meeting, R&M Consultants,Inc.1982f.Unpublished Eklutna Lake Data. R&M Consultants,Inc.,1981a.Susitna Hydroelectric Project,Regional Flood Studies,prepared for Acres American Incorporated, December. R&M Consultants,Inc.1981b.Susitna Hydroelectric Project Water Quality Annual ~eport 1980,prepared for Acres American Incorpora- ted,Apr i 1. R&M Consultants,Inc.1981c.Susitna Hydroelectric Project Water Qual ity Annual Report,1981,prepared for Acres American Incor- porated,December. Schmidt,D.~ADF&G,1982b. September. Ii i, I I ) Impoundment {.I ..I t,' I I J Siting,Marshall,1981.Handbook of Toxic and Hazardous Chemicals, Noyes Publications,Park Ridge,New Jersey. St.John et al.,1976.The Limnology of Kamloops Lake,B.C.Department of Environment,Vancouver,B.C. Symons,J.M.,.S.R.Weibel,and G.G.Robeck,1965. Influences on Water Quality,JAWWA,Vol.57,No.1. Symons,J.M.,1969.Water Quality Behavior in Reservoirs,U.S.Public Health Service,Bureau of Water HY0iene,Cincinnati. Trihey,W.,1982b.ADF&G Personal Communication,October. Trihey,W.,1982c.ADF&G Personal Communication,meeting,September 15. Trihey,W.,1982a.Susitna Intergravel Temperature Report (Draft). AEIDC. Turkheim,R.A.,1975.Biophysical Impacts of Arctic Hydroelectric Developments.In J.C.Day (ed),Impacts on Hydroelectric Projects and Associated Developments on Arctic Renewable Resources and the Input,University of Western Ontario, Ontario,Canada. USGS,1981.Water Resources Data for Alaska,U.S.Geological Survey, Water-Data Report AK-80-1,Water Year 1980. U.S.ArmY Corps of Engineers,1982.Bradley Lake Hydroelectric Project Design Memorandum No.2,AppendiX E,February. Vollenweider,R.A.,1976.Advances in Defining Critical Loading Levels for Phosphorous in Lake Eutrophication,Mem.1st.Ital,1drobiol., 33. !! 1 / /1 BIBLI OGRPAHY Acres American Incorporated,1982c.Susitna Hydroelectric Project 1980-81 Geotechnical Report Final Draft,Volume 1,prepared for the A1ask~Power Authority. Kavanagh,N.and A.Townsend,1977.Construction-related Oil Spills Along trans-Alaska Pipeline,Joint State/Federal Fish and Wildlife Advisory Team,Alaska,JFWAT special report No.15. Commonwealth Associ ates,Incorporated,1982.Anchorage -Fairbanks Transmi ssi on Interti e,prepared for the A1 aska Power Authority, .March. Joyce,M.R.,l.A.,Rundquist and l.l.Moulton,1980.Gravel Removal Guidelines Manual for Arctic and Subarctic Floodplains.U.S.Fish and Wildlife Service,Biological Services Program FWS/OBS -80/09. Burger,C.and l.Swenson,1977.Environmental Surveillance of Gravel Removal on the trans-Alaska Pipeline System with recommendations for future gravel mining,Joint State Federal Fish and Wildife Advisory Team,Alaska,Special Report Series,No.13. lauman,I.E,1976.Sa1monid Passage at .Stream-road Crossings,Oregon Dept.of Fish and Wildlife,Oregon. U.S.Forest Service,1979.Roadway Drainage Guide for Installing Cu1 verts to Accommodate Fi sh,U.S.Dept.of Agri culture,A1 aska, Alaska Region Report No.42. Gustafson,J.,1977.An evaluation of low water crossings'at fish streams along the trans-Alaska pipeline system,Joint State/ Federal Fish and.Wi1d1ife Advisory Team,Anchorage,Alaska,JFWAT Special Report No.16. A1yesk a Pi pe 1i ne Service Company,1974.Environmenta 1 and techni cal st i pu1 at i on comp 1i ance assessment document for the trans-Alaska pipeline system,A1yeska Pipeline Service Co.,Anchorage,Alaska, Vol.I. Bohme,V.E.and E.R.Brushett,1979.Oil spill control in Alberta, 1977 Oi 1 Spill Conference (Preventi on,Behavior,Control, Cleanup),New Orleans,LA.American Petroleum Institute, Environmental Protection Agency,U.S.Coast Guard. Lindstedt,S.J.,1979.Oil Spill response planning for biologically sensitive areas,1977 Oil Spill Conference (Prevention,Behavior, Control,Cleanup),New Orleans,lA.,American Petroleum Institute, Environmental Protection Agency,U.S.Coast Guard. lantz,R.l.,1971.Guidelines for stream protection in logging opera- tions,Research Division,Oregon State Game Commission, Oregon. [ f r I r [ r r 1 l [ I f I I I I l t TABLE E.2.1:GAGING STATION DATA I1 ' USGS Gage Drainage 2 Years of River Station Number Area (mi )Record Mile Denali 15291000 950 25 291 Maclaren 15291200 280 24 260(1) Cantwell 15291500 4140 20 225 Gold Creek 15292000 6160 J2 137 Chulitna 15292400 2570 23 98 Talkeetna 15291500 2006 18 97(1) Skwenta 15294300 2250 20 28(1). Susitna 15294350 19400 9 26 (1)Confluence of tributary with Susitna River. Ii L '~-=,-,---'~..,..--::::---- TAGLE E.2.2:BASELINE MONTHLY fLOWS (cfs) '--- Vee Devil Gold Susitna Maclaren-Chulitna Denali l Canyon2 Watana 2 Canyon2 Creek Station (Paxson) (20)(0)(2) (2)(32)(5)(21) Station (14 ) Talkeetna (15 ) Skwenta (20 ) OCT Max 2135 '4626 6458 7518 8212 52636 687 9314 4438 6196 Mean 1132 3033 4523 5324 5654 31250 409 4859 2505 4297 Min 528 1638 2403 2867 3124 15940 249 2898 1450 1929 NOV Hax 680 2200 3525 3955 3954 21548 265 f 3014 1786-----309li Mean 500 1449 2050 2391 2476 13247 177 1994 1146 1780 Min 192 780 1021 1146 1215 6606 95 1236 770 678 ax Mean 317 998 1415 1665 1788 9070 118 1457 842 1267 Min 146 543 709 810 866 4279 49 ~891 515 628 JAN Max 651 1300 1780 2212 2452 12269 162 1673 1001 7m Mean 246 824 1166 1362 1466 8205 96 1276 675 1070 Min 85 437 636 757 824 6072 44 974 504 600 rEB Max 321 1200 1560 1836 2028 11532 140 f400 80)-n~-T821 Mean 206 722 903 1153 1242 7409 84 1099 565 903 Min 64 426 602 709 768 4993 42 820 401 490 HARCH Hax 287 1273 15bD-------n79 1900 9193 12f~---1300---743-1200 Mean 188 692 898 1042 1115 6562 76 978 496 809 Min 42 408 569 664 713 4910 36 738 379 522 APRil Max 415 1702 1965 2405 2650 9003 145 1600 ~1G--~-17ao Mean 230 853 1099 1267 1351 7214 87 1154 569 1016 Min 43 465 609 697 745 5531 50 700 371 607 MAY Max 4259 13751f'5973 -T9717 ---21-8go----~414)ZU84-----2002)-7790 ---134-60 Mean 2056 7520 10355 12190 13277 60822 002 8371 4195 7920 Min 629 2643 2857 3428 3745 29809 208 3971 1694 1635 JUNE Hax 12210 34630--Q2842 -----zIT81~--)058U--_____rT62Tr----"'Il2'j~_________q~--19'040------40356 Mean 7306 19655 23024 26078 28095 122510 2891 22495 11610 10583 Min 4647 9909 13233 14710 15530 67838 1751 15587 7429 10650 JULY Hax 12110 2ZH9IT-~T8767 JTIB8---341100~"-16B81)4'649---~55'7D""-----,-zj'440~'25270 Mean 9399 17079 20810 23152 2391.9 130980 3165 26424 10560 17089 Min 6756 12220 15871 17291 18093 102121 2441 22761 7080 11670 AUGOSI Hax 10400 22710 31435 ->5270--------rr62;lJ 1383Jll-----)74I~~3670 18033 20590 Mean 8124 14474 18629 20928 2172q 109360 2566 22292 9331 13374 Min 3919 6597 13412 15257 16220 62368 974 11300 3787 7471 SEPT Hax 5452 12910 17206 19799 21240 104218 2439 23260 10610 13J71 Mean 3356 7897 792 12414 13327 .68060 1166 12003 5546 8156 Min 1822 3376 5712 6463 6881 34085 470 6424 2070 3783 ANNUAL Max Mean Min NOTES: 1 Years of Record 2 Computed 3651 2723 2127 7962 6295 4159 983J 8023 6100 10947 9130 7200 11565 9670 7200 59395 48148 31228 1276 975 693 12114 8748 6078 5276 4029 2233 10024 6306 4939 "~~'~~I r "',:;;'1 ~~1~;~'!r;:r,1.r~··-~/--',r"'-l r:m i·:~·>tt'-rt ~"""'0 i-'~r;r--,'-""1 r-1 r':::':'1 ~ Average River Mile Slope RM 149 to 144 0.00195 RM 14/:to 139 0.00260 RM 139 to 129.5 0.00210 RM 129.5 to 119 RM 119 to 104 RM 104 to 95 RM 95 to 61 RM 61 to 42 RM 42 to 0 TABLE E.2.5:SUSITNA RIVER REACH DEFINITIONS Predominent Channel Pattern Single channel confined by valley walls.Frequent bedrock control points. Split channel confined by valley wall and terraces. Split channel confined occasionally by terraces and valley walls.Main chan- nels,side channels sloughs occupy valley bottom. 0.00173 Split channel with occasional tendency to braid.Main channel frequently flows against west valley wall.Subchannels and sloughs occupy east floodplain. 0.00153 Single channel frequently incised and occasional islands. 0.00147 Transition from split channel to braided.Occasionally bounded by terraces.Braided through the con- fluence with Chulitna and Talkeetna Rivers..--0.00105 Braided with occasional confinement by terraces. 0.00073 Combined patterns;western floodplain braided,eastern floodplain split channel. 0.00030 Split channel with occasional tendency to braid.Deltaic distributary channels begin forming at about RM 20. TABLE E.2.6:DETECTION LIMITS FOR WATER QUALITY PARAMETERS (Cont'd) Laboratory Parameters (Cont'd) -Cu,Copper -Fe,Iron -Hg,Mercury -K,Potassium -Mg,Magnes ium -Mn,Manganese -Mo,Molybdenum -Na,S,odium - Ni,Nickel -Pb,Lead -Pt,Platinum -Sb,Ant imony -Se,Selenium -Si,Silicon -Sn,Tin -Sr,Strontium -Ti,Titanium -"I,Tungsten -V,Vanadium -Zn,Zinc -Zr,Zirconium R&M Detection L · .t(1)lml 0.05 0.05 0.1 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.10 0.10 0.05 0.10 0.05 0.05 1.0 0.05 0.05 0.05 USGS Detection Limit(5) .001 .01 .0001 .1 .1 .001 .001 .1 .001 .001 .001 .001 .1 .01 .01 Criteria Levels 0.01 1.0 0.00005 0.05· 0.07 0.025 0.03 9 0.01 0.007 (S) 0.03 \l __ ) J L.'. --.c. (1)All values are expressed in mg/l unless otherwise noted. (2)TDS _(filterable)material that passes through a standard glass fiber filter and remains after evaporation (SM p 93).. (3) TSS -(nonfilterable)material required on a standard fiber filter after filtration of atWell-mixed sample. (4).( )/ (ICAP SCAN -thirty-two 32 element computerized scan in parts milLion Ag,AI,As,Au, B,Ba,Bi,Ca,Cd, Co,Cr,Cu,Fe,Hg,K,Mg, Mn,Mo,Na,Ni,Pb,Pt,Sb,Se,Si,Sn, Sr,Ti,V,W,Zn,Zr). (5)USGS detection limits are taken from "1982 Water Quality Laboratory Services Catalog" USGS Open-File Report 81-1016.The limits used are the limits for the most precise test avail able. (S)-Suggested Criteria (M)-Migration Routes (Sp)-Spawning Areas TABLE E.2.7:PARAMETERS EXCEEDING CRITERIA BY STATION AND SEASON Parameter Station Season Criteria D.O.%Saturation G 5 L pH T 5,W,B L G B Color T,5 5 L Phosphorus,Total (d)V,G,T,5,55 5,W,B L Total Organic Carbon G,55 5 5 V,G,55 W 55 B Aluminum (d)V,G 5,W 5 Aluminum (t)G,5,55 5 Bismuth (d)V,G 5 5 G 'Ii Cadmium (d)T,55 5,W L 55 B Cadmium (t)G,T,5,55 5 T,55 \tI,B Copper (d)T,55 5 A T \tI 55 8·--Copper (t)'G,T,5,55 5 T,5,55 of! T,55 I ron (d)0,V,C 5 L Iron (t)G,T,5,55 5 ..T 8 Lead (t)G,T,5,55 5 A T,55 W,B Manganese (d)D,V,G,C 5 L Manganese (t)G,T,5 5 T,55 B Mereury (d)G,5 5 L 5 \tI Mereury (t)G,T,5,55 5 T,5,55 \tI T,55 B Nickel (t),.5,55 5 A..., Zinc (d)V 5 A Zinc (t)G,5,55 5 T,5,55 \tI 55 B l Stations o -Denali V -Vee Canyon G -Gold Creek C -Chulitna T -Talkeetna 5 -Sunshine 55 -Susitna Station Seasons 5 -Summer W -\~inter B -Breakup Criteria L -Established by law'as per Alaska Water Quality Standards 5 -Criteria that have been suggested but are now law, or levels which natural waters usually do not exceed A -Alternate level to 0.02 of the 96-hour LCSO determined through bioassay "'I, ,\ TABLE E.2.8:1982 TURBIDITY ANALYSIS OF THE SUSITNA,CHULl TNA AND TALKEETNA RIVERS CONFLUENCE AREA 1 1 3Suspended 1 Turbidit/ Sediment1 Discharge4Date Date Concentration [Location Sampled Analyzed (NTU)(mg/I)(cfs) j 1 1 Susitna at Sunshine 6/3/82 6/11/82 164 71,800 (Parks Highway Bridge)6/10/82 6/24/82 200 403 62,100 6/17/82 6/24/82 136 '22 48,700 \6/21/82 8/3/82 360 755 76,600 6/28/82 8/18/82 1,056 71,600 1 7/6/82 8/3/82 352 44,800 I 7/12/82 8/3/82 912 58,000 7/19/82 8/18/82 552 59,400 7/26/82 8/18/82 696 97,100 1 8/2/82 8/18/82 544 .61,000 8/9/82 8/26/82 720 50,200 8/16/82 8/26/82 784 45,600 8/23/82 9/14/82 552 1 8/30/82 9/14/82 292' 9/17/82 10/12/82 784 (Susitna Below Talkeetna 5/26/82*5/29/82 98I5/28/82*6/2/82 256 43,600 "5/29/82*6/2/82 140 42,900 5/30/82*6/2/82 65 38,400 (5/31/82*6/2/82 130 39,200 6/1/82*6/2/82 130·1~7,000' II Susitna atLRX-45 5/26/82*5/29/82 81 Susitna near Chase 5 6/3/82 6/11/82 140 1 1 (R.R.Mile 232)6/8/82 6/24/82 130 547 6/15/82 6/24/82 94 170 20,700 6/22/82 8/3/82 74 426 "6/30/82 8/18/82 376I7/8/82 8/18/82 132 18,100 1 7/14/82 8/3/82 728 27,300 l 7/21/82 8/18/82 316 21,900 ,\ 7/28/82 8/18/82 300 25,600 8/4/82 8/18/82 352 18,500 \8/10/82 8/26/82 364 16,700 8/18/82 8/26/82 304 I 8/25/82 9/14/82 244 I 8/31/82 9/14/82 188!9/19/82 10/12/82 328 1 Susitna at Vee Canyon 6/4/82 6/11/82 82 6/30/82 8/3/82 384 7/27/82 8/18/82 720 I 8/26/82 9/14/82 320 Chulitna (Canyon)6 6/4/82 6/11/82 272 6/22/82 8/3/82 680 l 6/29/82 8/18/82 1,424 7/7/82 8/3/82 976 7/13/82 8/18/82 1,136 7/20/82 8/18/82 1,392 7/27/82 8/18/82 664 I 8/3/82 8/18/82 704 8/11/82 8/26/82 592 8/17/82 8/26/82 1,296 ,\8/24/82 9/14/82 632 9/1/82 9/'14/82 316 9/18/82 10/12/82 1,920 :.~ I J l 1 I TABLE E.2.8 -(Cont'd):) 1-I 3Suspended 1 Turbidity2 Sediment Date Date Concentration Discharge 4 -\ Location Sampled Analyzed (NTU)(mg/l)(cfs)i Chulitna near Confluence6 5/26/82*5/29/82 194 5/28/82*6/2/82 272 I5/29/82*6/2/82 308 5/30/82*6/2/82 120 5/31/82*6/2/82 360 6/1/82*6/2/82 324 Talkeetna at USGS Cable 7 6/2/82 6/11/82 146 311 16,000 6/9/82 6/24/82 49 311 13,400 6/17/82 6/24/82 28 10,300 6/23/82 8/3/82 26 164 11,700 6/29/82 8/18/82 41 11,800 7/7/82 8/3/82 20 6,830 7/13/82 8/3/82 132-9,390 7/20/82 8/18/82 148 8,880 ?l7/28/82 8/18/82 272 16,000 8/3/82 8/18/82 49 9,730 8/10/82 8/26/82 53 7,400 8/17/82 8/26/82 82 6,490 )8/24/82 9/14/82 68 8/31/82 9/14/82 37 9/20/82 10/12/82 34 ---Talkeetna at R.R.Bridge7 5/26/82*5/29/82 17 5,680 5/28/82*6/2/82 39 6,250 5/29/82*6/2/82 21 5,860 5/30/82*6/2/82 20 5,660 5/31/82*6/2/82 44 7,400 6/1/82*6/2/82 55 9,560 Notes:1*Refers to samples collected by R&M Consultants,all other samples were collected by USGS. 2 R&M Consultants conducted all turbidity measurements. 3 Suspended sediment concentrations are preliminary,unpublished data provided by the U.S.Geological Survey. 4 Discharges for "Susitna at Sunshine"and "Susitna Below Talkeetna"are from the U.S.Geological Survey stream gage at the Parks Highway 8ridge at Sunshine. 5 Discharges for "Susitna at LRX-4"and "Susitna near Chase"are from the USGS stream gage at the Alaska Railroad Bridge at Gold Creek. 6 Discharges for "Chulitna"and "Chulitna near Confluence"are from the USGS stream gage at the Parks Highway Bridge at Chulitna. 7 Discharges for "Talkeetna at USGS Cable"and "Talkeetna at R.R.Bridge"are from the USGS stream gage near Talkeetna. J I I I J I , I ~f 1 1 1 ( 1 ( 1 I i 1 ( I (, l I .1 J j I ( 1 ( 1 ( 1 ( 1 I, I l 31 I I TABLE E.2.9:SIGNIFICANT ION CONCENTRATIONS Ranges of Concentrations (mg/l) U stream of Pro'ect Downstream of Pro"ect Summer Winter Summer Winter Bicarbonate (alkalinit y)39 -81 57 -187 25 -86 45 -145 Chloride o -11 4 -30 -15 6 -35 Sulfate 2 -23 11 -39 -28 10 -38 Calcium (dissolved)13 -29 23 -51 10 -37 22 -32 Magnesium (dissolved)1 - 4 o -16 1 - 6 1 -10 Sodium (dissolved)2 -10 4 -23 2 - 8 5 -17 Potassium (dissolved)1 - 7 0-9 1 - 4 1 -5 l -\TABLE E.2.10:STREAMS TO BE PARTIALLY OR COMPLETELY INUNDATED BY WATANA RESERVOIR (EI.2,185) ..j! .' I I .J J -I ! 4 4 5 3 4 4 4 4 4 4 4 4 3 3 Approximate Length Existing Approximate of Stream Susitna Elevation Stream Gradient to be River Mile at Mouth at Mouth Inundated Stream Name at Mouth (ft.msI)(ft/mile)(miles) 1•unnamed 240.8 2,185 380 mouth only 2.unnamed 240.0 2,175 1,000 mouth only 3.unnamed 239.4 2,170 500 mouth only 4.unnamed 238.5 2,165 600 mouth only 5.unnamed 236.0 2,140 500 0.1 6.unnamed 233.8 2,055 400 0.3 7.Oshetna River 233.5 2,050 65 2.0 8.unnamed 232.7 2,040 1,500 0.2 9.Goose Creek 231.2 2,030 125 1.2 10.unnamed ,230.8 2,025 F 1,400 0.2 11.unnamed 229.8 2,015 550 0.3 12.unnamed 229.7 2,015'1,500 0.2 13.unnamed 229.1 2,010 2,000 0.1 14.unnamed 228.5 2,000 1,300 0.1 15.unnamed 228.4 2,000 2,000 0.2 16.unnamed 227.4 1,980 1,700 0.1 17.unnamed 226.8 1,970 250 0.6 18.unnamed 225.0 1,930 400 0.4 19.unnamed 224.4 1,920 1,250 0.2 20.unnamed 221.5 1,875 --230 --1.0 21.unnamed 220.9 1,865 1,000 0.2 22.unnamed 219.2 1,845 350 1.0 23.unnamed 217.6 1,830 700 0.5 24.unnamed 215.1 1,785 900 0.3 25.unnamed 21.3.2 1,760 1,000 0.4 26.unnamed 213.0 1,755 600 0.6 27.unnamed 212.1 1,750 1,200 0.3 28.unnamed slough 212.0 1,750 13 0.5 (full length) 29.unnamed slough 211.7 1,745 1,000 0.3 30.unnamed 210.2 1,720 400 0.7 31.Jay Creek 208.6 1,700 120 3.2 32.unnamed 207.3 1,690 300 0.9 (full length) 33.unnamed 207.0 1,685 160 1.0 34.Kosina Creek 206.9 1,685 120 4.2 5.unnamed 205.0 1,665 1,100 0.5 (full length) 6.unnamed 204.9 1,665 750 0.4 (full length) 37.unnamed 203.9 1,655 800 0.7 8.unnamed 203.4 1,650 350 0.5 (full length) 39.unnamed 201.8 1,635 400 0.8 o.unnamed 200.7 1,625 1,000 1.0 1.unnamed 198.7 1,610 400 0.7 2.unnamed 198.6 1,605 700 0.6 3.unnamed 197.9 1,600 500 0.6 4.unnamed 197.1 1,595 650 0.7 5.unnamed 196.7 1,590 1,000 0.7 6.unnamed 196.2 1,585 550 1.0 7.unnamed 195.8 1,580 350 1.1 8.unnamed 195.2 1,575 200 1.3 (fu.ll length) 9.unnamed 194.9 1,570 200 1.7 o.Watana Creek 194.1 1,560 50 10.0 (longest fork) I J \ .( TABLE E.2.10 -(Cont'd) Approximate Length Existing Approximate of Stream Susitna Elevation Stream Gradient to be River Mile at Mouth at Mouth Inundated Stream Name at Mouth (ft.msl)(ft/mile)(~Iiles) 50A.Delusion Creek --1,700 200 1 c,.-(tributary to Watana Creek) 51.unnamed 192.7 1,550 400 1.5 (full length) 52.unnamed 192.0 1,545 200 3.9 (longest fork) 53.unnamed 190.0 1,530 1,300 0.5 54.unnamed 187.0 1,505 1,250 0.7 55.unnamed 186.9 1,505 2,000 1.7 56.Deadman Creek 186.7 1,500 450 2.~ TABLE E.2.11:STREAMS TO BE PARTIALLY OR COMPLETELY INUNDATED BY DEVIL CANYON RESERVOIR (EL.1,455) [ l [ [ [ l r r 2 2 2 2 2 2 2 2 2 2 Approximate Length Existing Approximate of Stream Susitna Elevation Stream Gradient to be River Mile at Mouth at Mouth Inundated Stream Name at Mouth (ft.msl)(ft/mile)(miles) -' 1-Tsusena Creek 181.9 1,450 250 0.2 2.unnamed 181.2 1,440 250 0.2 3.unnamed slough 180.1 1,430 10 0.6 (full length) 4.unnamed slough 179.3 1,420 250 0.1 5.unnamed slough 179.1 1,420 500 0.2 6.unnamed slough 177.0 1,385 600 0.1 7.Fog Creek 176.7 1,380 125 1.0 8.unnamed 175.3 1,370 75 0.6 9.unnamed 175.1 1,365 1,100 0.1 10.unnamed 174.9 1,360 650 0.1 11.unnamed 174.3 1,350 350 0.3 12.unnamed slough 174.0 1,350 15 2.0 (full length) 12A.unnamed (tr ibutarv to slough)--1,350 550 0.2 12B.unnamed (tributary to slough)--1,350 550 0.2 12C.unnamed (tributary to slough)--1,350 1,600 0.1 13.unnamed slough 173.4 1,340 20 0.5 (full length) 14.unnamed 17.3.0 1,335 600 0.1 15.unnamed 173.0 1,335 1,000 0.2 16.unnamed 172.9 1,330 1,300 0.2 17.unnamed slough --..172.1 1,320 15 0.8 (full length) 17A.unnamed (tributary to slough)--1,.320 2,000 0.1 17B.unnamed (tributary to slough)--1,320 2,000 0.1 18.unnamed 171.4 1,315 2,000 0.1 19.unnamed 171.0 1,310 250 0.6 O.unnamed slough 169.5 1,290 15 0.7 (full .length) 1.unnamed 168.8 1,280 1,400 0.2 2.unnamed 166.5 1,235 350 0.6 3.unnamed 166.0 1,230 1,250 0.2 4.unnamed 164.0 1,200 2,000 0.2 5.unnamed 163.7 1,180 1,350 0.2 6.Devil Creek 161.4 1,120 180 1.4 7.unnamed 157.0 1,030 400 1.3 8.unnamed 154.5 985 3,000 0.4 9.unnamed (Cheechako Creek)152.4 950 500 1.6 L l , I, \., I '1 - (, ( l \ 1 \ '\ -1 \ 1 \ 1 \ 1 ( Tl ( q ( -l ( 1 ( TABLE E.2.12:DOWNSTREAM TRIBUTARIES POTENTIALLY IMPACTED BY PROJECT OPERATION River Bank of Reason Name Mile Susitna1 for ConcernNo. 1 Portage C~eek 148.9 RB fish 2 Jack Long Creek 144~8 LB fish 3 Indian River 138.5 RB fish 4 Gold Creek 136.7 LB fish 5 Trib.ta132.o 132.0 LB RR 6 Fourth of JUly Creek 131.1 RB fish 7 Sherman Creek 130.9 LB RR,fish 8 Trib.a 128.5 128.5 LB RR 9 Trib.la 127.3 -127.3 LB RR ·10 Skull Creek 124~7 LB RR 11 Trib.1m 123.9 123.9 RB fish 12 Deadhorse Creek 121.0 .LB £.ish,RR 13 Trib.@ 121.0 121.0 RB fish 14 Little Portage Creek 117.8 LB RR 15 McKenzie Creek 116.7 LB fish 16 Lane Creek 113.6 LB fish 17 Gash Creek 111.7 LB fish 18 Trib.@l 110.1 110.1 LB RR 19 Whiskers Creek 101.2 RB fish 1Referenced by facing downstream (LB =left bank,RB =right bank). -! J TABLE E.2.13:SUMMARY OF SURFACE WATER AND GROUND WATER APPROPRIATIONS IN EQUIVALENT FLOW RATES Township Grid Surface Water Equivalent Ground Water Equivalent efs ae-ft/yr efs ae-ft/yr Susitna .153 50.0 .0498 16.3 Fish Creek .000116 .02100 .00300 2.24 Willow Creek 18.3 5,660 .153 128 Little Willo~Creek .00613 1.42 .001907 1.37 Montana Creek .0196 7.85 .366 264 Chulina .00322 .797 .000831 .601 Susitna Reservoir .00465 3.36 .~ Chulitna .00329 2.38 Kroto-Trapper Creek .0564 10.7 Kahiltna 125 37,000 Yentna .00155 .565 Skwentna .00551 1.9.Q ...00Q7?5 __.560- ] j J' " J ] J SUSITNA RIVER -LIMITATIONS TO NAVIGATION River Mile Index (R&M Consultants,1981) I j, l 1 j.. ! TABLE E.2.14: River Mile Location* 19 52 61 127-128 151 160-161 225 291 *Reference: Description Alexander Slounh Head Mouth of Willow Creek Sutitna/Landing Mouth of Kashwitna River River Cross-Over near Sherman and Cross- Section 32 Dev il Canyon Devil Creek Rapids Vee Canyon - Denali Highway Bridge Severity Access to slough limited at low water due to shallow channel Access from creek limited at low water Access from launching site limited at low water Shallow in riffle at low water Severe rapids at all flow levels Seve re rapids at all flow levels -Hazardous-"'bt-Jt accessib Ie rapids at most flows Shallow water and frequent sand bars at low water TABLE E.2.15:ESTIMATED LOW AND HIGH FLOWS AT ACCESS ROAD STREAM CROSSINGS Drainage 1 Ii AXIa 30-Day Minimum Flow (cfs)Peak Flows (c fs) Basin (mi )Recurrence Interval (yrs)Recurrence Interval (yrs) 2 10 20 2 10 25 50-- --- Denali Highway to Watana Camp Lily Creek 3.70 0.8 0.6 0.5 25 54 78 96 Seattle Creek 11.13 2.4 1.8 1.5 74 147 205 248 Seattle Creek Tributary 1.49 0.3 0.2 0.2 10 24 35 44 Seattle Creek Tributary 2.70 0.8 0.5 0.4 13 29 42 51 Brushkana Creek 22.00 5.5 3.8 3.4 115 217 299 354 Brushkana Creek Site 21.01 4.9 3.5 3.1 121 228 315 374 Upper Deadman Creek 12.08 3.0 2.1 1.9 64 127 177 211 Deadman Creek .--.-.--Tributary 21.28 4.6 3.3 2.9 138 263 363 432 Deadman Creek Tributary 14.71 3.2 2.3 2.0 97 189 262 315 Watana to Devil Canyon Tsusena Creek 126.61 26 19 17 780 1309 1744 2000 Devil Creek 31.0 6.7 4.8 4.2 199 369 506 597 Dev il Canyon to Gold Creek Gold Creek 25.00 5.4 3.9 3.4 162 304 418 497 1MinimUm flows estimated from the following equation (Freethey and Scully,1980, Water Resources of the Cook Inlet Basin,U.S.Geological Survey,Atlas HA-620) bed Md,rt=aA (LP +1)(J +10) where:M =mInimum flow (cfs) d =number of days rt =recurrence interval (yrs) A =drainage area (mil) LP =area of lakes and ponds (percent) J =mean minimum January air temperature (OF) ·°1 ] "1 ") J '".q'~j J J ___J::l --~_I_----~------'__...J_"-.J -, --'..J ...J ...J.tOi.:..I --l..-- TABLE E2.16:AVAILABLE STREAMfLOW RECORDS fOR MAJOR STREAMS CROSSED BY TRANSMISSION CORRIDOR riansliiissliJnTIne Per iod of Drainagi Area 1 Crossing from USGS Gage Continuous Gage Stream Name Description USGS Number Record (mi )(approx.) Anchorage-Willow Segment Little Susitna River Near Palmer 15290000 1940-61.9 35 mi.dis Willow Creek Near Willow 15294005 1978-166 7 mi.dis fairbanks-Healy Segment - Nenana River #1 Near Healy 15518000 1950-1979 1,910 2 mi.dis Nenana River 112 Near Healy 15518000 1950-1979 1,910 20 mi.dis Tanana River At Nenana 15515500 1962-15,600 5 mi.u/" Willow-Healy Inter tie Talkeetna River Near Talkeetna 15292700 1964-2,006 5 mi.dis Susitna River At Gold Creek 15292000 1949-6,160 5 mi.u/s Indian River ------82 15 mi.u/s Lf.Chulitna Chulitna River 15292400 1958-72,1980-2,570 40 mi.u/s River near Talkeetna M.f.Chulitna Chulitna River 15292400 1958-72,1980-'2,570 50 mi.u/s River near Talkeetna Nenana River Near Windy 15')16000 1950-56,1958-73 710 5 mi.u/s Yanent fork ------N/A 1 mi.u/s Healy Creek ------N/A 1 mi.u/s Watana-Gold Creek Segment Tsusena Creek ---- -- 149 3 mi.u/s Devil Creek ------N/A 3 mi.u/s Susitna River At Gold Creek 15292000 1949-6,160 15 mi.u/s 1Areas for-ungaged streams are at the mouth. ;d/s =downstream,u/s =upstream.Distances for ungaged stream are from the mouth. Averages determined through the 1980 water year at gage sites. Mean Annua\ Streamflow (cfs) 206 472 3,506 3,506 23,460 4,050 9,647 8,748 8,748 9,647 TABLE E2.17:DOWNSTREAM FLOW REQUIREMENTS AT GOLD CREEK Flow (efs) Month Dunng F1111ng Operabon Jan 1,000 5,000 Feb 1,000 5,000 Mar 1,000 5,000 Apr 1,000 5,000 May 6,000 6,000 Jun 6,000 6,000 Jul 6,480(1)6,480 Aug 12,000 12,000 Sep 9,300(2)9,300 Oct 2,000 5,000 Nov 1,000,5,000 Dee 1,000 -5·,oo(i"" (1)JUly 1-26 6,000 27 6,000 28 7,500 29 9,000 30 10,500 31 12,000 (2)September 1-14 12,000 15 12,000 16 10,500 17 9,000 18 7,500 19 6,000 20 6,000 J J j J J \_1 ___-'""f.-."c:;_~_--J _~~__-__~~__..JJ __Jill __-U _~.....J __.-I __..,..j __..:.:..,\__-J TABLE E2.18:WATANA INFLOW AND OUTFLOW FOR FILLING CASES -IU:')U:'9m~ UutFlow (efa)UutFlow (efa)Uutflow (efs) Inflow Inflow Inflow 1 (efa) 1 (efa)1991 1992 1993 (efs)1991 1992 1993 1991 1992 1993 Jan 1,340 1,340 1,340 1,340 1,190 1,19B 1,19B 1,000 1,071 1,071 1,071 1,000 Feb 1,13B .1,13B 1,13B 1,13B 1,01B 1,01B 1,01B 1,000 910 910 910 910 Mar 1,02B 1,02B 1,02B 1,02B 919 919 919 919 B22 B22 B22 B22 Apr 1,261 1,261 1,000 1,000 1,127 1,127 1,000 1,000 1,00B 1,00B 1,000 1,000 May 12,15B B,690 3,276 3,276 10,B70 7,402 3,649 3,649 9,715 6,247 4,016 4,016 Jun 25,326 20,005 1,000 10,527 22,644 17,323 1,103 1,939 20,238 14,917 1,B67 1,B67 Jul 22,327 5,309 9,031 1,000 19,963 2,945 2,181 2,163 17,B42 2,B36 2,B36 2,836 Aug 20,142 14,993 B,649 15,B59 lB,OOB 12,B59 B,105 10,19B 16,095 B,934 B,713 B,713 Sep 12,064 6,743 6,597 12,064 10,7B7 6,967 6,967 10,7B7 9,641 7,331 7,331 7,331 Oct 5,272 5,272 1,000 5,272 4,713 3,261 1,000 4,713 4,213 1,230 1,000 1,000 Nov 2,352 2,352 1,000 2,352 2,102 2,102 1,000 2,102 1,B79 1,B79 1,000 1,000 Dee 1,642 1,642 1,020 1,642 1,46B 1,46B 1,000 1,46B 1,312 1,312 1,000 1,000 Note:1 Prior to 1991,-no water is stored in Watana reservoir. i --~.Jj ---~._-------------',jiiJ .1/1 _..ii:od ..II ~I._fill •1_ TABLE E2.19:FLOWS AT GOLD CREEK DURING WATANA FILLING 'IU~:>U%~U:;; WrIng tllllng Wnng tllllng Wrlng t lHing Pre-Pre-Pre- Proiect 1991 1992 1993 Project 1991 1992 1993 Project 1991 1992 1993 Jan 1,640 1,640 1,640 1,640 1,457 1,457 1,457 1,259 1,290 1,290 1,290 1,219 Feb 1,393 1,393 1,393 1,393 1,238 1,238 1,238 1,220 1,096 1,096 1,096 1,096 Mar 1,258 1,258 1,258 1,258 1,118 1,118 1,118 1,118 990 990 990 990 Apr 1,544 1,544 1,283 1,283 1,371 1,371 1,244 1,244 1,214 1,214 1,206 1,206 May 14,882 11,414.6,000 6,000 13,221 9,753 6,000 6,000 11,699 8,231 6,000 6,000 Jun 31,002 25,680 6,675 16,202 27,541 22,220 6,000 6,836 24,371 19,050 6,000 6,000 Jul 27,331 10,312 4,034 6,003 24,280 7,262 6,498 .6,480 21,486 6,480 6,480 6,480 Aug 24,655 19,506 3,162 20,371 21,903 16,754 2,000 14,093 19,382 12,221 12,000 12,000 Sep 14,767 9,446 9,300 14,767 13,119 9,300 9,300 3,120 11,609 9,300 9,300 9,300 Oct 6,453 6,453 2,181 6,453 5,732 4,280 2,019 5,732 5,073 2,159 1,860 1,860 Nov 2,879 2,879 1,527 2,879 2,557 2,557 1,455 2,557 2,263 2,263 1,384 1,384 Dec 2,010 2,010 1,388 2,010 1,785 1,785 ,1,317 1,785 1,580 1,580 1,268 1,268 f _I TABLE 2.21 POST-PRO.IEeT FlObI AT \J(IH,IH:(d'~,) WATANA AlOHE :CASE C YEMi OCT N(lV 1JF.r.J(:N FF.Po Hi-:F:M'R /'i(I)'.WN .1111.AliI)SfP tdH-!II ?d, 1 :5,","4,,\'nL\•.,11~!8~l.~~970:),6 W):'j{L~!1lI)l'll).a I~W~L7 ~j!I:'$~!.~j 4H~;:L9 4M7i'}')l)~S:~",8,~(j1.0 77.',1.9 2 5840.9 61:-40,7 77H.•O 71~9.9 62C,'O.0 f,4ML3 ~j(;74.:~71nJl.1 ·~B:m.~}477tl,:\.BIl(lR.O 52b~••5 M~ilj'.O 3 70a2.9 10164.1 :1.1617.4 10165.0 9157.5 n24~.7 7507.5 5J26.B 5002.3 1797.2 8436.3 6391.0 7"'9.7 4 8269.3 10750.7 11397.6 9709.4 H'n~.2 B:i.I:;','.4 H(l8~j,t.113nl.'6'4~1:59"l,4:j6(l.~'8071.6 ~j54::L:)ln~~~;.3 5 ~691.2 6591.6 I1JOO.2 977S.3 9119.6 9149.7 7646,2 8J69.J 4962.2 4590.a 6320.6 5545.~7J~3,B 6 5684.0 7246.1 11665.9 10?78.8 9367.0 R3Y7,8 7644.4 5258.9 5174,6 6849.6 14063.1 8457.B 8J45,~ 7 7,"~!0.0 9~'jB2.1 11 Hj~).O 'J70'J,4 9071.~i lI~!I),';,1 7'1~!L 9 l)~jOl).l ~11)all ",>!lSlll.7 11)()~j:"j,-1 B~!/::;'I)YI)46.5 8 7778.5 10270.5 1182J.4 1026~.5 950~.5 8446.7 7648.7 70(l~.7 7123:4 4748.4 A777.7 725~.1 B3Rl,O 9 9605.4 10921,9 12J74.9 10J71.:I.9353,2 3~85.2 7969.0 6004.2 4963.6 4755.7 8303.4 7550,0 84:i5.1 10 5731.9 651?7 7772.5 9971.5 926~.5 B20~.7 7~R9.3 '6Y~R.7 4UJH.2 4780.9 8969.2 7390.3 lJ~~.1 11 9736.0 10207.4 11738.7'10290.9 9455.4 11472.8 7773.5 950119 4370.41812.9 7733.1 4975.6 82)0.4 12 6482.7,10371.7 120B9.6 10670,4 9621.3 8R~2.7 8668.6 1P116.3 520~.3 ,47~7.4 9380.2 6(176.2 R~19.7 13 6050.~10257.3 11376,8 10499 ••9573.9 3633.5 11:1.61.0 0042.3 16919.9 7579.4 :1.:1.01)4.0 J296.n 9649,7 14 9130.6 1050~.9 11H2~.3 10199.4 9501.2 8395,3 7480,2 11611.4 4959.4 9~1~.9 124GH.O 7780,0 9168.1 15 6516.0 779J.1 1:1.311,1 9742.5 90Y9.1 11086.9 7312.3 5JJJ.l 18353.5 S020.1 9~08.2 7253.2 8131.5 16 5759.3 65J~.B 7538.2 9560.5 90B9.2 8319.0 7936,0 j711,6 4962.8 5167.4 8274.1 10381.7 7~92.4 17 9791.7 9559.3 11320.Q 7950.9 9301,2 9496.4 9042.0 S25U.1 6476.3 455~.1 75AO.9 6764.1 7999.0 18 5722.3 6504.8 7606.3 9992.7 9J47,8 8101.2 755~.3 ~14~.1 6837.7 55~0.2 161811.9 B?~3,5 8171.0 19 7~ifl9.~j 99~!1l.2 llH~!I)..,>1050{Ll <,Ill?,'1.'J <,I()n.l H~l('ll}.:~nllb,~!n~'j~l,a ~)i'i):),~i Il')n.~'j 7647,\~811'/,,1;.0 20 5756.8 ~5.3.1 7573.0 7636,5 906~,3 R197.7 7553.b ~2~11.9 4051,7 4629,7 9756.0 7674.0 J02~,9 21 ~';91)7.9 lI({l)9.,4 7:-1~j6.~!n~~O.11 (I'L~I),~!1>619.0 ~Hl';!,".:,!'~j<l:W.J..\'i(12.6 '}i'47.~~H~!:-l:Ln i'<\I):L.l ,1-'1/0.0 22 5971.4 6790.2 7879.0 7336,3 ~419,1 6614.8 ~E23.1 ~501,H 5166.8 4YJ~,7 8685.6 7048.9 6~lE.H ')3 7°£)2 10'''(1)'j 'l'I)']"'Q 10"':1.'1111)7 (I 'lf17"77 (1'»0 ')lb""1 )(H')l)\7"I"f 1)'119"70'"'''",.,,'-'il..on l )•"l\l )T •f.(,})n "h"l.)'I I l )j ~.I ),l (I )\.0 'C.(."~)t I \It •)l t'-i <..,.oJ't 't...),)\".".~)J "-'11/t t. 24 5697.0 6589.5 11362.9 992~,0 9JJ6,J 8385.b 7617.7 52~R.9 4973.6 45B~.1 9726.7 S3?~,7 7~4~,S 25 5i'30.5 657J.2 7622.2 709:1..7"6638.2 813'1,0 757~,5 9442.3 1859.5 4651.8 930J.7 b836,2 JO~2,D 26 5901.1 6782.7 7811.4 727~.2 6358.6 A5~7.0 573Y,O 53~6.J 7869.7 6791,1 9U~6.6 6(1~:~,J ~79B.3 27 77~i,1.1 9~jl):).1 1l)?'n"L,%4tL~~'iO:'j'}.!W,!l)~!.~J/6:L~~jl\H7.l 'I?,q.:'i 4~'iS7,9 J,I)~j't:L~i MIll 1.I)?,~'}3,1 '28 5827.7 lob:??.!7677.0 71~~5.9 62:~1.4 7:in.l 7S'(l7.0 5:i~A,.6 1~~-1"'L1 47,~~i."(}':)6?:~7Tl::~.1 ',';l,/'B,f, 29 5692.1 1)108.0 12096,1 10~6H.4 9584,2 117~3,4 0112.0 7950.5 4H44.1 4603.4 9022.1 7H25.~81/6,0 30 5881.8 6683.9 7750.7 7?15.6 6306,8 64J7,9 ~679.0 8309.9 51~2,B 7742.0 B~10.J 7626.7 6Y~9.3 31 56111.2 11305.1 12148.4 10360,5 9547.5 8690.7 8101.6 6960.2 5~J2.6 92Jl.7 7070.J 7020.0 R6JO.l 32 9053.3 11290.9 11501.4 10037.5 9287,5 8400.7 7806.6 7207.6 4874.0 5632.0 19391.0 9316.0 949J.5 MAX 9605.4 l1J05.1 12374.9 10670"9876.9 9072.:1.3668.6 12218.0 10353.5 951~.9 19391,0 10381.7 96~9.7 MIN 5664.6 6504.8 7538.?7091.7 623J.4 b~AR,J 567~.J 525t~.9 483~.5 4~55.1 6320.6 487~.6 645~10 MEAN 67M"l flM171!10;~I)I),'J n?9.:!IIMI:"),]llI')?II.~~1~79.1 n119 ..~Mi2B.;~!j~'i-1<J.6 1J7'l3.n n,ll).7 B',)J.3.1 C',Wi L_~~L3 L-..:;L....1J'__ff:'.~ ~/.'"I'..'...''.,•II~---~~----~~~~----~~~~~-----.-------------------------------"------Jill ...-II ~--------.J TABLE 2.22 1'1£1 NTH LY Ii fi XI MUM,I'll NIH UN,fil·HI liEAI~FI.mls.AT 1,1 f.:T f.lNf; MONTH POB r··PI·W.JECr PRE·-PROJECT loJATANA AIONF WATANfi/DFVIL CfiNYON 11AX 11IN"NEAN l'1AX MIN m·:f.lN MAX MIN NEAN OCT 6458.0 .2"103.:1 .~4 ~j~!~~.B 96 O:'j •4 :5664.6 6?M..1 :t i 9 (I (I.7 rj::;64.1 9764.4 NOV :~~j~!:'j •t).1020.9·":'~O:l9 •~:I..1.JO~j •:I.brjO 4.H B,~b7.7 Ll.04A.4 bbA:~•::s 9U.~.6 DEC ~!258.5 709.3 :1.41"1.1i 1:,~:~"l4.9 nj38.2 1(1:~()(I •9 :I.:?:'H)(":~"17n).9 10BR:1.2 JAN 1779.1/~~:~,~•~!:1.165.~j 10670.4 70'11.7 Y:i99.~!U497.6 7227.~s :I.O~!07 •~i FEB :I.~.i60.4 60?•:I 983.3 lJli76.9 6:~31.4 861i:~.:~:I.HI;,):I..6 1)~~72.(I ~~S';:!<1 .6 MAR 1 :"jf,O •<)569.1 H98 •:i 9072.:1.6468 •~i BI)YB.:i :I.O:H ri •b 64~j9.B 9()~:;9.2 APR 1965.0 609.2 1099.7 IU)(~H .6 ~j\.L,74.3 "I'17B.1 Ij'j91J.9 :)1 (1(1 ....7793.9 MAY 1~:;97:~•J..~!U~jl .•2 10.1::;4.7 1~!~!:l 8 •0 5~!:Hl •'-)nil '},,~7::;0:1..6 4072.9 ~HJ26 .() JUN ·'~~841 .9 1 :~~~:{3 •<1 ~'~~023.7 1 H:~:'j:"i ,~j 4B:~~j.5 (-'6?8.:i 61,~?1••9 :U 98.6 51?3.6 JUL '")87fJ7 )1:W71,.O :'~OHll).1 nj 1.~j .')4 ~j rj ~j •1 ~j ~j.,)'I •6.66~!5.6 :44<1~!.~j 47:~6.1.:.\ \,.l AUG ~H 4~~5.0 :1.3"112.1.·:1.0628.5 :I.9:191.0 b:~20.6 977B.ij 14 (14:1.~?::S~~n:4 .4 5947.5 SEf'~.7:~():).~'j ~)7 Ll •~j:1 0 7 9 ~~•0 10~Wl .7 4Hnj.b 7:HO.7 1:~n7~~.9 4009.~!78:18.4 ANNUAL.9f;32.9 c.l00.4 ~O23.0 9649,7 64~jS',0 80 1 ~j • 1 IJB::S~?~'634:4.8 BO 1 ~.i.1 '$ • TABLE 2.23 f'RE-PfWJECT FlOl~Al fHlLlI CRI:EK (!:"f!.) MODIfIED HYDROLOGY --.-!J YEAR OCT NOV J.t n;JAN FEB MAR M'R l1{i \'JlIN .lIll flUB ~;FF'I'il~NUAL 1 ,,~n:'j,I)~!~W~~,I)14~il/,I)11)21,1)7BH,I)726,I)871),0 11511),1)19AI)I),O 2~(1)1).0 198(1),0 3~il)1 .1)8032.1 2 3848.0 1300,0 11 00.0 960.0 820.0 710.0 1617.0 14090.0 70790.0 21570.0 19670.0 21'40.0 9106.03~j~j71,1)~!7'14 ,0 1//1)1),I)1,~I)l),()11)1}1),I)8BI),I)nl),I)5419,1)J2370,1 26391),0 21)921),0 144(1),1)'/5~j2 .148202.0 ;~H7.(1 1700.0 1100.0 820.0 820.0 1615.0 lY'70iO 27320.1 20200.0 20610.0 15270.0 10090 ••,5 ~j6l)4.1)~!II)I),I)l~jl)l),I)1.~1)1),0 11)1)1),1)7BI),I)1235,1)17201),1)25251),0 21)361),0 2611)1),1)12921),1)%81.665370.0 2760.0 204~i.O '79,1.0 1400.0 1100.0 1~?00.0 931'9'()2~',lIo0.(1 ~!'i'~jMI.0 2:'j7:)(1.()14290.0 10?~6.47il7~j 1 ,I)191)1),1)1~il)l),I)98l),1)971),1)'/40,I)951),1)17660,0 JJ340,I)Jl090,1 24530,0 18330,0 11473.385806.0 ~HI50.0 2142.0 1700.0 1:)(10.0 1?-00.0 ~700.0 13750.0 30160.0 23310.0 20540.0 19800.0 1O:H:t\•I9ll~!J.2,0 ~S9~)4 ,0 ~S~!64 ,I)19,,:),()D07,\)114a,o 1533,1)12900,0 257(1),0 22831).0 22540,1)nj~jl),I)11476.4104811.0 2150.0 1513.0 IHH.(I 1 ;~0'7.(i 980.0 1250.0 15990.0 23320.0 25000.0 31180.0 J6920.0 1(1:)~)9.9116:)~):LI)~!B:"il),I)~!~!I)l),l)184:LO 1 <\~j~!,\)1197,l)13(1),0 15701),1)155JI),I)229(1).0 2J591).0 205(1),1)9712.3127794.0 ,3000.0 2694.(I :2·1 :,2 I 0 J 7~i,1.0 1B10.0 2650.0 17360.(1 29450.0 ?4570.0 22100.~13370.0 IOB09.:\13 ~j916,1)VI)l),I)UOI),I)1901),0 1~jl)(),0 11}1)1),I)171)1),0 i2590,()4J270,O 25850,0 2J550,O 15891),1)11~j63 .2146723.0 '2BOO.0 ~!OOO.0 1600.0 1500.0 1(100.0 1130.0 19030.0 26000.0 34400.0 ?3670.0 123?-0,0 1107:'.915,,1\4'/,I)2~!~jO ,l)1<)94,0 1043,1)9b6,O 7.l~LI)74rj,0 <\J07,O 50580,0 22950.0 1.'>440,0 ni71,O 9199.6166291.0 ~a99.(l 11:11.0 960.0 860,0 900.(I 1360,0 l2990.0 25720.0 27840,0 21120,0 193~0.0 10lt-8.B17nO~j ,0 ~!1)9H,0 16~H ,I)141)0,0 noo .0 1~100 ,0 1775.0 ,9645,0 J2950,O 19860,0 21a30,O 11750,0 94:U .8184163.0 :lMO.()1:)00.0 1500.0 14 no,(I 1/'(10,0 1167.0 15480,0 29510.0 26BOO.0 32620.0 168'70.0 1121B.5194YOO,l)~!:S :'j.~,I)~!I)~l5,I)19a1.0 1901),l)1//(1),l)1911),0 16100,0 J1550,O 26420.0 17170,1)lIfU6.1)9al0.6204272.0 1906,0 1330.0 .JOB6.0 92/.0 B:~3.(I 1022.0 ,9852,0 2052~.0 18093,0 16322.0 9776.0 7200.121:U24,O 121~j,0 ab".0 '821,()7b:LO 77,~.0 10UO,I)l1JOO,I)1116JO,O 22660.0 19980,0 '11~!1,1)7591.2225288.03-107.0 2290~O 141~~.(1 10:~6.0 9:)(1,0 1082.0 3145,0 32930.0 23950,0 3J910.0 14440.0 102:)1.023~j84],t):S09:S,O 2~HO ,I)n.w,o ~!O~!:L I)la~!.L 0 1710,0 ~1090,1)J4<\JI),O 22770,0 19290.0 124(1),1)108U5.5244826.0 2253.0 14t.5.0 1200.0 1200.(I 1000.0 1027,0 8235,0 271100.0 18250.0 20790.0 9074,0 80B6.~!25 :~n.LO 1 ~j~!~L I)II)~H,1)874.0 777,0 724,0 '192.0 16100,0 17870,0 1»800.0 16220,0 12250,0 n.H.o263739.0.1700.0 :160:~.0 1:)16.(I 1-171,0 J400.0 1593,(1 15350.0 32310,0 27720.0 18090.0 16310,0 Ion:>..,27 77~i9 .1)19n,o "llWl,O 974,1)9~jl)•()I}00 ,0 un,o 1~!1l~!0.1)~!43al),1)10941),0 Ivaoo,o 6a(H ,0 8Hl9.3283874.0 76~.O I (I 24(l:~,O IB29.0 1618.0 I~JOO.0 1600.0 126110.0 37970.0 22870.0 19240,0 12640,0 HI1 09.0297:)71 ,0 ;~~)~!~';•()2~j(i9 ,I)~!0~!9 ,i)16/1:1.0 1bl)~j ,l)1702,1)11950,0 19(51),0 21020.0 16J90,O 8607,0 1119·1.5~50 4907.0 '2~j3:'j.0 H,81.0 1397.0 j;!f:t,.O 1~!(iO.O 1450.0 13870.0 24690.0 211080.1 20460.0 10770.0 9489.3 MAX a~!12,l)~59:)4 ,I)~i264 ,l)~!4~j2.0 ~!02fl,0 1900,0 2650,0 21890,0 50530,b 34400.0 32~20.0 21240.0 11:';/)5.2~1It1 3124.0 121 ~j,0 866.0 824.0 768.0 7n.o 74:).0 374~,O 15530.0 ~e093.0 16220,0 6881.0 noo.!MEAN ~jMj4,.1 2·17,~,3 1788,1)14,,:),7 1~!tl~!.~~11.l4.U IJ51,3 IJ276,7 2H095,1 2J919.4 21726,]13327,2 9.170.1$ L-:i 1 ~,,LJ:W:?L--~L:-oJ -----L...-.-------'-~~---- ;"","L ",,>a,','lI I I JI .'.J I--..-~--------'---~-~---_.------------'--.....ill --'---.J .....--J ~....------------.-------=-------.----.---- --"- ! ~---' .TABLE 2.25 HONHll.Y H(IXlIiIJl1s.IHIHI1tnh ()N[I MrAN FI..lJI~!';()TIWI.))Cl"~EF.'K ~ HDNHI MAX F'~~E-F'rWJECT IUN ',NEAN POHl·,PRl1.JECT IJ~TP.N(,('LI'JNF,IJ(iTflNf,/[lEVXl.C(iNYDN ,MAX MIN MEAN MAX MIN MEAN OCT 8212.0 ;H ~~4.0 ~)b54 .3 1 :l i'8~!•:')6;~;~:l •8 BO:l!t,(1 10983.0 6"·~)3,;~776/4.9 NOV ;~'11:14 ,t)t 21 ~j ,t)247,~,:~1:t <J79 ,9 [)741 ,~j <Jim),?"UHI1,U 7"();~,<J 'u,:w.o [IEC 3264.0 B66~0 ·178B.O 13380.4 If,i'8 •c;1 01,9:~•::s 1a134.,1 804(1.:'j 1:t :n(I,9 JAN 24~~?()O~?4 ,()1465,/1 L'H~?>:')?1.'79.~{<J;'1)7,U 1:C~t)45 ,a I 4~?;~,<)"c):)9.".7 FEB 2028.0 768.0 1~!.I\2.3 :I O=~I\I\.:'j 6·1:~i'.O ~~CJ :'):i.I 1 :l1~~2.8 64 ~i i',;~10190,9 MAR t 'Jt)t),t)'7 L'l •()1l:lI\,H 'JeLl.1.•7 6:'j~'6.7 n~~~?~S,7 "'t)6()4 ,~?ld,Hl.,l 9~!8:).6 APR 2650.0 7 4~j.0 l;;~H.;;9~53.6 ~'jIH1,1 T14(1.1 9.i'~j9.4 :W:'jO,4 B:lOO.1I MAY :c~tI190.(),D 4~j ,()1:~~~7.S.?:U~:I,;:S <\•')1I0,S 1 >::~1 t).\t).\,'J "~!=HH),t).~t)t)C),()B'lO.S.3 JUN 50580.0 :l :'i ~'j ~{O •():W095.1 2f,091 •f,6000.0 11 "1 9 ,::,L~~05.2 6(IO~I,(l !.I'HI,};?,9 JIJL :~1\.1\t)(),t).l H()<},~•t),~?~<}1 9 ,<\1~·i.l.~'iJ,.9 ,lo,4 H <)>t)<J:lU'\"S 1:tB4f,,:c~f,40Il,t)R:Hll.3 AUG 32620.0 1 f,~!20 •()21726.7 2t.494.0 :I.;~()O 0 ,()1;n7B ,II ;~U.4 (,.?1 ;~OOO,0 1 2 6 :~=~.~'i SU'2 1 ~?1\C)•t).,!,ua:J.•t)L~,1;U.::?:U~';06 >~,HO:'jO >~j ~)H;'S <J ,,~un=~o,t)93t)().t):J.0:)1 0.3 ..HINU(,L 11565.2 72(i().1 9670.1 :1.:1 .1\1'.8.8 'lH:H .:~,971\:'i ,II :t:IA73.3 7"176,4 I}7 ":'j •1\ $ ~ I "!'if:;;';:I '-----~L..:...:L---:~~"-'-'_:_'-"-'----'~y,:;\I -- --....:.:::.~---~-l-:-=-=------~~_,._--__.--__-~~--_-.....J ~--:J----_C.~.-.~--~"~~~---,-J ~_-.J _.c=--:J::....;~.-J TABLE 2.26 f'RE-PRO.IEeT FI.OW (iT SlINRHWF (cfl;) 111lIHFHJ)U'{))/WLI1GY YEAR Or-T 1l0V DEC -.MN H.I!IiflR f\f'R lillY .Jlm .\lIL AUG SEP (:HNlI{11 1 141)();S .1)~i(IJ9 .0 ;Sll 11 .1)~!14B.1)~!~!7 11.0 21);S;S .0 2311,1)22410.0 45111J.1)39179.1)54049.1)27734.0 :.!I)3 "7 .1r)12226.0 471~!,(1 3804.(I 2no.0 2-i:~:).0 ~tH~.O 3563.0 4219~.0 50012.0 69414.0 ~0356.0 51~69.0 nU(>.l... :5 1;S71 ~L 0 ~i70~!.1):S7B2.1).H71).1)~!~H1.1)nH2.1);!.157.1)11 1.511.1)1>117311 ,I)M937 ,I)53~:I,1)31.1):0,I)~!2.ll7.5417394.0 7199,0 4080.(1 2B111,O ~!:~4:~.(I 2:~1 '1 •(l 4~9~,O 50302.0 64(175.0 ~42Jj.(l 1Y 54.0 33737,0 :r-\:)44.:~~D~!27 .1)~jt)n.I)3977.1)31>67.0 211BY.1)24n.l)321)4.1)J2595.0 5401)5.1)53JBA.l)57"1)1.1)2031A.1)~!19:.!t.86121B8.0 6340.(I 4:~1:\.(I :w:n.0 ~qB9.0 ;!~'Tl.(I 26~fl.0 21758.(1 696B6.0 70894.0 77692.~353U5.0 .:?6(141.67l.ll)l.l •l)4.J1l7.1)Jltll.1)~!61~!,I)~!2n\~.1)2~!l)9 ,I)nH.o ;s:a:i7.0 7:S941.1)BO~i[19.0 (19~~S4.1)H4ni.0 nriB:~.4815252.0 7 (l2~'•(I 4907.0 ~006 .(I ~471.(I 2U44.(;2907.0 34140.0 1Y1~3.0 ~23(1~.0 ~3?43.0 40121.0 2(I:i:l(l.79.ll1:S99.0 91>:S~!.1)111;S9.1)'\l)\~1.0 ~!9<J6.I)~!!>4~S .0 3399.0 27759.1)60152.0 59851).0 511902.0 2l)09H.0 ~~~!lJ~!·1.210.11578.():i;S:~l,(~:~:)9~.I,(I 33B7.0 ~(l:)~'.(l :-~~~ll(l.(l 20Y5.0 29460,0 ~~2B~.0 ~752!~0 7194l1.0 3691~.0 2~345.B1.l 1 ~"il ~l.l •0 l>H~i.1)~lJ~!:-S.1)~ori9 •I):S;!O 1.t)~![,7rj .0 2928.0 J4l102.0 39311.1)30224.0 55J15.1)43006.1)~~'n~il .3121H9f..(1 610<).(1 :'i :)"04 •(I 47:W.O ;{4=Jf.l.(l :~41l(1.(I :)1(19.0 3243ll.0 1,(1118(,.(1 ~:~M(I.O b(161l..(I :~~(I"l1,(1 2:Hl"J~).?1 ;S l<l~i7Y.0 M>~)1.1)411:!I),O ~~!~!2 .0 ~S~S<l2.I);!9nj,t)~S ~iB L 0 :!'<\~j~!I).0 81:'j;S7,0 tl 11:i/)•I)1>.l1 8.l.0 ;sn 711.0 n7b·~.6 14 U9:)r..(1 6(,:);t.0 4690.0 407",(1 :~(,::':i •(I :~:~99.(I ?(I?5.(I 3~24~.0 56629,0.70219.0 5293B.0 '9182.0 2~n(l.g1~j Ul~jr·j~j.I)~j91)7.0 3~j:S;S •t)V91.1)~!4'17.t)',!t).1.;S.O ~!~"sa.l •t)lI/l 4~j,1)l1.l I)n •0 ;';lJH:Ui>I)·'Ill;S 74 •0 n~!\~1 •0 ~!JlJ/l1.91615473.0 747;>.0 4:'i:S6.(I :~:~n.(I :~91>::I.(l naB.O 3J\~~j,0 i4:'i97.(I :m4l111.(I (,::;042.{1 :'6:rl~l.(I :'i:~70:L (I :>497:i.:\17 .1.11~!()O.1)~j:S~!1.I);S9Mi.t)3"04,0 ~SO()9 .0 :·!ll ni.I)3590.0 ~1l479.Q 69569.1)35~4J.0 62007.1)JOI5b.1)n9~S~.71811551.0 429:).(I 3 B:)I,.0 Uln:.(.:\~IC)1,(I :?79;\.(I 2639.0 3291~.0 66162,0 771'~.O R2741.0 37319.0 :n:)06.J1'I It)~}I)b.I)~j4IJ.t)-4~j6:~.I)4HlLI)J9lJ!>.1)~SB'/lJ •Q 4359.0 36961.0 76770.1)69133.0 46730,0 21)B05.1)~!4.149.1 20 '0524.0 4,,8:i..(I :~2~?n.(I 2f.l19.0 1731.0 :!(,n.(,244~.(l ~j306.0 49349.0 41156~.(l 42970.0 24032.0 1795(1.721<J 4 .l.~•I)J9711.I)~!lJ4n.0 ~!.~Ot).0 ~!4 'W.I)2~HJ~!•I)J150.0 25607.0 47602.0 60171.Q 54926.0 27191.0 :!I)~S'I3.7221226-1.0 74(,"7.(1 4nO.(1 :~:~~!:'I.(I ~!:'i14 •(I 2:~~):i t (i 2640.0 1(1652.0 7~208.0 ~47D7.0 74519.(1 32402.0 241,29.0;.~~S 1 'I ~S l:L I)II 74:'i.I)49~!2.1)·12:j7.1);W t).l •I)~S;S~S~i •I):rno.l);(I>1HO.I)M>lJ~i/l,l)(>nn.1)ril~!~j4.1)~SH~i.~.I)~!<\41)7 .124:I.~S~8R.(I 00111.(I 40:10.0 3312.0 :~9B4.(i :~Ml\.(I :W~~j.O Hl21:·,.(1 :)~'n:~.(l :='l1U.O :H(lB~'j.O ~~:'inB.o 2023:LB::!~.;.I.:t.:~1I4 .0 4b~19 .1);S~i24 •I)~!BB2 .0 ~!:o'j.1.9 •I)~!~!~!t).t)~!Yl.LI)~Sl4Bll.1)4:\11;LO ~i:l;!b7.1)4.J~!2~!.1):!91H.1).l91·]~j.l26L_I:S(I;~.-(1 ,w:m.(l ~S777.0 :S~j4 I.•(I :~C)I)O.(I :?Ili (l,(I 3160.0 29380.0 721l3~.0 75692.0 51~78.0 3~567,0 :~:)()~!:~(2.,-,.l:j:j[i:i.1)-<\:!:SU.I)~!734 .0 ~!~jI)7.I)~~\'i~j~))()~~~~lILO ~S~!9·LI)~!~!lj75.1)ri/>.JMl.O ~j~j~jOI>.o :jU~j:j,l)UI~'j02.1)~!()l)i)O.7'., ~!8 ,.(,\L,:~O.(I 5B88.0 528:),(I 42:~:i .0 :~M(/.(I 317j .0 ~537.(l 27292.0 1l777~.0 62194.0 5~157.0 32719.0 2~,::l;~1 •b29.l7 ~S 9 ')•I)71:S0.1):i~H:L I)4U.LI);·tn7,l);son .0 J5<\2.0 2271)7.0 40044.0 51930.0 4211B.1)22142.0 .l<J9:1.0.230ll:~:~:\.0 ~r.'H;.0 4:~on.0 :~l,74.(1 ;~?(ll,.()2963.0 ~704,O 3JB16.0 591l49.0 71774,0 40897,0 2~79(1.0 n~.44,:~ MAX :l.1l~'j:j:j •I)()t):S~!.t)III ;S9.t)·11:W.0 ~19a\~.0 :S:i ~la •t)511)9.0 50~02.011.ll)73.1)80569.0 112747,1)5371)3.1)n:-iHS .4tUN9416.0 ;W71l,(I ~?n4.(l 2:)(17.(I '.nl.o 201:1,(;:!02:';.(I Bb4:'i.0 :~nu.o ,'R56:·I.(i 4~~l1n,(1 1ll:)O;?O :i n~i(l.'IMEAIIDnj'l.n ~W'I:S .n 4~!1B.:j ;~~H~S .B :!l)'I t)•:S 26~!H.7 J143.4 27709.9 A4495.B 6J211B.~51>510.2 321>56.0 :·!:S:;;!:·i.6$ =--L TABLE 2.27 POST -f'RIl.Jr;f;1'FI.mJ taT SlIHRH HIE (C'f~.) Wt\TMh)M.ONE :CAllE C -~-~ YEAR OCT NOV DEC Jf.;N FHt MAR APR Hf.;Y .JIIN .J II I.AUG SFf'MIIIl J(>,I. ( t 14947.7 1J271.7 IJ727.4 11630.5 10592.5 Y~jJ\-\.7 Y014.6 lY3Y4.6 34034.9 44603.0 46969.0 20714.6 ~!1-1!lO.9~o']~767.B 10245.4 10613.8 cnu .9 ~)(l:)~?0 7992.5 7n:'i.l :m'1~(1.:~4:5109.6 ::;441>:).5 ~j(l6Hf1tO :Wl:?~\.O 2"Ot.l.4.... 3 16203.0 IJ696.0 13019.4 12360.5 10027.5 Y1'/3,]90.\<),,\12.1MI.:\41%6.'/4762.1.3 44~3.0 2.11'1].0 ~!~~IM.5419377.6 1~192.9 14196.4 1170R.5 10659.5 9828.7 10995.6 4664(1.4 475~4.B 4143~.6 ~1:4~.0 27767.(1 24B~4.4&:146')9.3 100U4.0 140lJ.~.4 1~!~j~jl.~j l1~!O~j,~j Y9~4.7 9907.6 29267.5 40290.5 4099J.2 4J,OI.0 24756.0 ~!IH7S.2"6 14012.8 1153~.(I 14429.4 12H17.5 11505.5 .100HH.7 n()1.6 ~!0~?9H.B 49979.;"~139:'i5.7 6H2~B.1 ;\0;\9::'.0 ~.):'iM.7.B714523.7 123~1,0 13277.4 11502.5 10602.5 '}nO.7 W}11 6 IIy07 n 'l ·····,l·.,9 6 -So·'··~4 0·9<Ji~6 0 39 0 °,.-(;V:'i83.9J)~.(\)\,),),,»)..,),l,»,)")",),»), 8 18822.5 1502~.0 15(123.4 12896.5 117B7.5 1(1355.7 ~610.6 30964.5 61001.4 '1710j.5 447(13.0 40534.0 :n:'i:)0 •7921969.5 17026.0 16255.4 12957.5 11312.5 10154,7 10102.6 24605.4 43617.H 44H53.0 46362.d 216A9.3 2~~509 •91013641.9 10114,:r :!0249.4 12277.5 1U75.:i 11791,7 9598,6 262HB,1 5079'1.6 51R08.H 5697&,8 31338.4 24660.111IH10l.5 14408.9 14939.4 1294Y.5 11517.5 10196,7 9~31.6 31339.7 3094U.0 4J530.8 43725.0 31876.0 ~!2'Jl7 •71217429.4 11102,9 1~620.4 13629.5 117~~.5 10~91,7 11812.6 2B916.4 43305.2 43547.6 50316.(1 32001.0 24lin.on15991.7 14651.0 147J~.4 13112.5 1165H.5 10496.7 10294.6 2122U.H 6U413.8 51R91.7 52297.9 33250.8 2Mj83.31417526.5 14046.0 14806.4 1296'1.5 11937.5 9~'10.7 B7'8.6 31557.2 40925.(1 58967.3 44414.6 26162.(1 ~!H:H,11:3 19893.9 13901.0 13649.4 11687.5 10763.5 nj2-\.7 9094.6 10399.3 86534.6 4J773.3 41934.0 22996.0 ~!4~j:~3.6161~472.9 11639.6 11003.9 12070,5 11278,5 10329.7 10138.6 213'12.6 42237.8 46973.5 47255.0 '17859.1 2411~~.21721779.5 13315,0°14081.4 12294.5 11325.5 10396,7 10301.6 14643.3 50105.7 4J64~.6 52177.0 27706.0 n~m9.41814003.5 9597.6 10;\'10.7 1:~:)3B.:'i Ut,10.~·,1030 01.7 9342.6 ~9490.6 48287.8 60687.9 72H~I.4 32459.6 269~1.51914276.5 13406.9 14679.4 IJ071.5 12J02.5 11409.7 11062.6 33520.5 58821.3 53J57.6 41560.0 213A9.0 ~~4992.92012833.8 94:i7.1 972H,O ~\441.5 10047.5 li:j~\].7 9145,6 18622.9 36691.7 37323.7 38648.0 24336,0 18fl79.22112920.9 97M.~j '}'J94 •'}n94.~!8~!M.l 8.n6,'}7939,8 21578.7 38185.6 47108,t 46946.0 27370,0 21)"J 19.6'1'"1 14467.4 11760 •.8 11121.6 956'1.2 fll~;~i,7 82<tH.7 7649.4 1~296.6 5376~.(I 48599.3 55758,0 27262,0 ~J~':)~7'.2....... 2:5 17194.1 14738,9 15038.4 13147.5 12117.5 10346.7 9913.6 ~2424.')49027.7 47214.0 4J964.0 31056.0 ~!4:H 1.224149B3.8 10629.6 14146.4 12202.5 11300.5 1(1157.7 9524.6 16186.9 '11047.3 39915.0 427Y5.(I 25464.0 2076::;.2'1 ,-14()I)H .0 9917 •~j 10214.6 9un.:~:H!l7.:~97:H.7 9619.6 2UOJ9.3 J3791,9 J9949.9 J9002.0 26164.0 199J4.2.0.,) 26 15111.3 102'16.3 10311.7 960'1.4 82;HI.:~8:W:).6 76B7.8 23054.5 54016.3 59052.7 45538.(1 2H557.0 n1HL8"·7 17642.0 122J2.0 12050.4 11397,5 10671,5 9792.7 9997.6 19U2~.3 41336.3 4J07fl.6 44355.0 19671,5 211 ~j9 .0"-, 28 13474.2 105B9.4 1127'1.5 10018.2 8l.M}.:)9653.3 10240.6 24277.2 6HR64,3 47232.1 47917.0 27379.0 ~!~:\67.t.29 In')?~!Dbn.7 W4~!'}.11 :t~S1I)~.~j l1~j'\;L~j 10~j1.L7 11)l~'1~j"S 1942.S,O =S~j,Ht).9 4H~)3.~.un8.1l n~:~:),o 211)94.0:iO 13330.9 103B7.0 10746.1 97::;:?8 IH~.7.4 B339.7 RO~5.1 29016.6 42067.0 54604.3 40437.0 25320.0 :?1IlB~\.9 MX 21969.5 170~A.0 16255.4 13629.5 12302.5 1~409.7 11312.6 46640.4 8A534.6 6J556.4 72831.4 47359.1 n:HI3.9"I I t~12833.8 94:;7.1 9nn.o 9187.~~BO~12.0 nn.~)7649.4 10399.3 3094B.0 37323.7 37720.0 19671.~18879.2MEAN16t)7~.7 12J67.2 IJ022.6 11703.7 10601.4 91107.9 9500.0 24090.2 48011.1 40334.4 47769.6 29165.7 ~~:~:·j·29 .2.. .'~i~~~,L-..;L-.L.J '__o! ___J ~~-----~------ X-I 6 ____~~..-...;.J -'_._~--"-1---,~__---____.-oJ ---.....-1M --~------"-.-~,'--~----:;,.-------~--- TABLE 2.28 F'F:E-f'rW.IF.CT FUlIJ AT SUSITNA (cf~.) i-lllIHFXEJ)H'())I~OLOGY ....I •.:-.....1 ...J -....~.~...~•:.J -~ ..~. YEAr.;OCT NOV DEC -'f.:N fEB 11flR APR H~Y •11m .JUt.flUB SFf'f.:I'HHJ(:I. 1 :~MWJ .4 11 '"sll'7 .1 /)1'n .0 ,~07:t .9 r'")r:r:'r'~)~P\~.7 5656.9 66293.5101615.7124839.8106431.8 39331.2 42-114.7,)(.,I,)),) ')lflO26.1 6932.8 59BO.9 70n,6 7:)~\-1 •~\,1,~~81.5 7354.2 5927',5 82254.612316-1.1100946.9 73471,0 'Hn~:~,1L 3 310~';2,,~1\~:16~S.tl ,~'J(Hl.~)lIV4.~i 71):16.<I ~)a~):~.0 ~)911~j,1 4~j'l94.:1 U~!~)4l .:U .H:i21 .811 M 1I6.1 W,!076.3 4'J!l~!:L 4444S'52.4 16289.1 9746,0 8(IM~.7 6774.5 6349.1~7992.6 B8840.0130561.3125949,2 97610.0 44167.7 It lJ27~',55201\~(L~)11 !l~!lJ •1 ~)~!71 •t>'7?02.0 49n.l 4(J"79.7 6J05.3 511516.410111101.0116731.612115116.7 66275.3 4~)nO.4623895.7 9167.8 61B:~,O 12:>4,6 ~845 .1 5~H·i.6 6412,4 58164.0169044.8148876.5120120.0 53504.2 .:H·1:~~',171'J9:!.L 4 10~)21.9 7~!'J~I.7 617()'~!tdlJO .n \~~1:!4 •1.9841021.6 2154~.5 14146.3 10600.1 8356.1 7~~~i~i .1 7705.3 63204.4176?lR,814031P.312-1812.9 B7025.0 5B911.9952636.0 1988&.6 10635.3 n)~)2.9 6~llJb.'f (h~78.1l 0098.6 70J20.5112U96.81222a~.299603.5 53053.3 4"78:\0.11030543.1 ~'~·j2R.4 4763.4 779~;.1 t,~j64,:\51,11~).~)6~67.1l 56601.4110602,314~216~BI38334,3 67903,5 49606.5112~)7~·;4.1 11)l fl4 •~j 7004 .,~,S 71,~.:S l>~~.1I)•l)~)(I~H .4 5829.6 500l>1.6 1I4134.4129403.411J771.6 81565.<\H.l72.51233782.3 1291-1.2 13768.2 12669.1 10034.0 9:192,6 Y~~(l2,6 8::;4 ~:;fI,71 :;171:>d 138%0.:>1i66 IJll.:>62504.3 5:>111.21.3 2~1i):!:L 7 1 :il)<\.L:l wn~s.,~90~)0 •1 II UI~!,~)~·;9~·iO .6 66J5.2 ~4533.0163l)49.014J441.3121220.574306.<\~)3~!:i4 .814?771 oS.2 10751\.~j 886-1.6 86/0.7 n::):\,.~l,(l:H:.1 S5 64.7 5'390:\.2 R:>64 7,~\1464;?(I.11M,f'b.8 70782.4 4:>n~),41:').rJ84,~.~i 1.l70 1.,S ~),S~!I~.O ,S3~"i1 , 1 ~)7M .6 <\9 11)•<\r.0r:---,.',"l ')r:'-')"),..(.")'..r:"<14:\38.1~JJO.H J~~J~.~lJJl~6.41~480d.8 ~~,79.J 46109.1I 16 287·16.I]'10458.0 t.12,~.6 69:H,9 .',19::,.B tl1t.9.9 7120.1 {94~5.ltl100741613"406.5111845.989944,3 1t711n,:> 17 :~g;~j.L 2 1~!31:!.:'i 91 ~)9 •~i 30:iO .Il 7409.'".7l)<Jl).~)1l~)4(L 3 ;F:Sll.4:l~!~)IB2 .'!117:S07.<\1.1!1~~!9.:i ~;m:.~?~i '1/470.1182l.396.2129c.2.t.P.321.9 BO:W.:>7726.1 6683.?nBO.6 .)BI06.6d48BO.~L~6.\06.3UI31f1.0f,~5,.7,(1 :>:~on.61937724.5 15972.1l 15081.0 11604,2 11532.2 lITn ,I)1I7 ,~~~.6 I)<\14:"1,~!U7H,~"7 •~!BI)~H.L /):'IM17 <\.~)4na4,1I :')0,"\99.02026322.5 11 OBf••4 7194.:>692·1.0 b163.~~5~1~~~,:\6112.0 52951t.Ol0B336.2jI55-17.9 9707/).0 57771.6 41917'9.8212';!,~fU.4 ,S7~)9 .:1 ~)O.lll.<l ,~O?<L ~!~)~iIll •~~:')7~H ,,~5769.1 5JOJ6.2 94612.11329S~.7117728.0 30534.3 <1 ~jl)1 4 •0r)'1 32817.316607,:!86:B.:?6508.7 6~'~i3,F;~iBll;~.6 :i7117 .~);~9B09,312?;'58.21 ~9l 83.41 :~:!.;HO.1 l,9(1~?1.2 48289.9L'" 2.~.~271d.:!149~!1.9 1l7?1).3 lJ:i71).7 H<l:'ja.~~MI·I:·).B l>894\9 ~4062.017t>02J.7142?B6.81(751)6./)60220,4 ~i4~10::;.32426781.9 1-\~:~;:~.9 8147.1 7609.2 7n6."l l,:H2.6 7608.2 6453~.0122797.1123362,2107260.845226,8 4:).1:'3.5",.:-~!097:L 7 11)l!:i.3 MB1.0 7401 ,,~fI7'17.3 t.~~9.L 7 6962.8 61<\57.0 67830.0102134.J a0251.5 56123.5 :~f,~!85 •1....J '1'1<);'20.0 10400.0 9419.0 8~jS'7 •('I 7 f)(l4 •(l 7(r4fl.(I 6867.0 47540.0128800.2135700.0 91360.1 77740.1 4610:~.6"'.:> 27 .H ~j~)l).1)99:U .0 f)OI)I),0 ,S~)2'J .0 ~j6.1.4 .1)~·i~i,~B .1)7253.0 70460.1107000.0115200.1 9<JA50.1 43110.0 HOB9.22830140.0 18270.0 13100.0 10100,0 89H,(1 6774.0 623~.0 561~0.0165900,311t3900,(I125500.183Bl0.1 5:>97~'.:~~~9 ~W2~Sl).1)1 ~!,S:ll).I);':'j~!9 .1)697<\.1),S?;'1.0 Mj91).I)70JJ.0 411670.0 1)07JO.0117600.1102100.2 55500.0 421)1)2.43036810.0 1500<),0 9306.0 Ban,O 7~\411.0 703?0 86B3,O 81260.1119YOO.OI42500.0128200.0 74340.0 :i:~676.8 MAX 52636.0 21547.5 1501l1.0 12669.1 11532.2 <Jl n,6 9(102,,~'H 1'1:1.~!1 n~!W •Hl111lH 14.II DH~i~i<l.~110421 8.<I ~)970L 9tlIH18026.1 .',799.::s 476:~14 f,(171 .9 4993.1 ·1910.4 5530.8 29809,3 67838.010718-1.3 80251.5 39331,2 :\l)~185 .1MEAN3(41)1.0 1~!aO;'.7 :nU.8 79Ml.9 71)7 L 7 ,S~~J~,!•~~6967.3 60750.5124534.8132379.5111997.7 66752.7 <111307.6$ '---L-L ~--'"'---...---'-~~/ -'>--.-- -~~~-~ ~---::-~"-~-~;-~-~ ~~,.:.-----.-:----- '----~/'--.~----- TABLE 2.29 POST-F'RD.JfCT FI.OW fir Sll~;XTNA (ef!;) ~lt\lMI~'M.ONE :CASE C YEAR OCT NOV llEf:JAN FEB I~M-:(.:PR liM'JUN JUL fillB BEf'MUW fIl. 1 27914.1 111999.0 1631~.4 14962.4 13572.0 12938.4 12360.5 63270.1 90037.51103lJ.a 7U551.8 40311.8 43:")58.5 ')20567.9 1;1·'6.').~!1V9(1.7 1;\455.5 12911.9 122JO I (I 117~?6,;i :'i:'j,W6,8 6B~ln,11 Ofu:m.6 n'J.76 ,~\1,1:'i;U.0 40508.4... 3 33542.6 24351.8 17104.9 17164.8 15J52.9 lJ364.7 12690.7 46404,6111776.2120008.1107266.1 76896.3 49H68.4 Jj 46936.0 24283,0 19862,4 16959.2 15091.0 13061,5 14696,2 8517R.4114051,111J154~B89000,0 39197,7 "'9~jt.9.6 5 21640,9 16U21.115330.U 16092.5 13309,6 12491.4 lJ009.1 55100.9 94366.5104J38.8114496,7 62655.3 4:'jn3.8625720.5 14362.8 16299.4 J6145.1 14161.6 12927.3 13116.0 56704.8149338.013J930.2110646,1 48514.2 51 O~i:j.3723441.1 10515.9 17411.1 15069.7 15147.3 IJ836,1 IJ805,8 79032,6143262.7151802.0122521,5 99299.0 ~j9,\97 .584539'.1 29~41.5 24262~7 19490.6 16672.6 141164.8 14408.9 60a2H.91~H067,21251j7.0116272,980~3a.o 5BS'11.8956206.5 27000.6 20751.7 16443,4 L47«)3,4 14190.5 14902.2 67166.9 95762,6107233,2 89068.5 5462 ••6 48~)15.71032607.0 14311;6 lr4~O.B 166H5.6 140110.8 13177.2 13171.4 53429.3 97110,913~504.6123363.1 6?826.9 4 09~~()dit129324,6 10150.4 17121.0 15606.8 14626.5 IJ163,1 12533,2 46599.3 75771.4114710,2102J01.6 70355.4 444~~8.91234215,7 20908.1 23884.6 21559.6 18350.5 16704.3 16506.2 81935.1134134.3123876.1106596.5 ~H4J4.3 ::;::;020.(I13:11)4,1.,210.17,3 19<1?I,O 119;0.6 IH?9,l)l:!~62.3 lJ331l':J ril21.2.61,J'/3'l.IH:mi17,01l2337/69;H6.?~)~~o 71.51431286.7 18748.5 18981.0 17561.2 16170,1 13~69,8 12268.3 50215,4 69913.912716R.6 98183 4 67762.4 -1~.425.81539175,2 19695,6 15742.4 15241,6 14079.1 12422,1 12234,4 37290,5128638.010974J.l 87839.5 45938.8 4:-jl)06.a 16 29746.8 14625.6 12594.5 15649.4 14512,3 13601.6 13823.7 46231,0 93B2~.412033R.OI02725.9 04100.4 47034.41740123.7 20306,5 19275.7 Ih921,J 15905,7 14602.2 14751.9 50~76.2105719,5106009.010089~J61437.3 48094.71828848.7 18265,2 f4B06.6 16919.0 16042,6 14194.9 13984.2 54693.211700~.7jI9B69.2127402.404607.6 5~'''4B.91941295,0 2J066.7 25197.4 20494.7 19949,7 16283,7 1546b.2 90702.7119919.0114136.2 81704.5 42868.3 ~H~!cl2.a202R632.J 16062.5 13694.5 13676.5 144BO.0 130~7.0 12815.6 5~?70.9 95618.910430A,6 92754,0 57295.6 ·12Y2B .1212,"W9.2 12~)flJ.B 1~!163.:~12U,B.4 lU~19,4 .l1n6,~j 11),',I):L9 4B9~!7,7 U~H9~j.7119321.HI097<lB.O a076J,U 4~j~170.02235020,7 2MOLO 14824.B 12717.9 1189:L:j U'lH0.3 10796~9 ~q4:):i.~'91)Hl2.21~!299::1I7114::;49.1 _~:~881.2 46:!~!(I.~!23 35644.3 22915,0 10907.2 10270,2 16774.8 14157,5 IJ593,5 70306,915BI95,6127708,8100306.6 57120.4 ~j4 709.52428177,7 19464.5 18263.5 16499.7 15793.2 13824.3 14391.8 62505,9103911,4111596.2 9B970.8 15452,8 4:jl)B:L 0'").-23699.7 15JJ1.a 12771.6 IJ706,9 12695.61J905.4 IJ666.4 50011.1 57116,9 90867.2 76031.5 53173.5 :~10'24 .2",-,,) 26 22332.3 15709.3 15953.7 14655.4 13052.3 12543.6 11394.B 41214.5109980.7119060.7 85270.1 70730.1 4449fL 127J3621,~17927.0 16116,~15419,5 IJ9JO,5 12H79.7 13156.6 67400.4 YI970,310217~.1 71850.1 50079.5 44247.5:·~8 32994.2 22971.4 19089.5 15887.2 13939.5 132~6.3 12936.6 53165.2146991.61?89J8.111R260,1 80470.1 5~l12;,.22933123,2 19172.7 176~5.4 15861,5 150H7,5 141(}1,7 IJ736,6 45309,0 70496,110J823.3 97710.2 56193,0 43186.2~50 38917.9 J9739.0 15744.1 14901.8 1~197.~12400.7 13044.1 77200.7102118,0125330.3119740.0 72P70.0 52422.5 MAX 56206.5 29541,5 25197.~21559.6 19848.7 16704.3 16506.2 90702,715BI95.6151802.0127402.4 99299.0 ~;9h97.5!-lIN 20567.9 12~66,2 11420.8 12747.9 11399.4 11726.5 10608.9 32453.9 57l)1~.9 90067.2 76031,5 38197.7 37021,2~p..~AN f 32723,0 19JJ1.1 17115,8 16150.7 14732,8 IJ511,6 13324.0 57930,7100050.0117425.510J257,1 6J2~2,5 4S:Ul.2,.'~'-------...:.L.ii L....:.,"r)-----..J "---------.;~----,.-.., ~-- :.i"~;'.. .~,--_L~,-.---.-.-/--~~_-~--.::---.::':=_---l _~-_-_ail ~-_._~_--c_-.J_=,-~~_JIliIi ~~-:-J ~~~.~_~-=--~J-J TABLE 2.30 I1f1NHIL.Y MAXIMUU,IHNHHIl'ls f.ll~JJ I'1FAN FLOloIS AT ·HIJlHHHIH: " 110tHU F'IlBT···p:·m.IECT F'F:E-f'r~OJF.CT loIATANA (·II.flNF.~I(l TANA/I1FV ll.C r."Hlml Mr;X IHN ,11EAN l-lAX MIN HE;:'IN i-IAX I1IH HEAt-I OCT 18555.0 91\16.0 1:~7~)1\,n :~:ill69.::i 1.?833.f)16(1'/(;•'1 :·~:i ::;:U"9 :t:H -1:l ,t,1 :'iBf.B,'7 NOV ~1 o:~2 >I).3 cJ'7H ><):HI'l:L B 1/02l>>0 <J .1\~;j ~I >:I.~.'~~:1 b l a>2 :t.1.>'i~!6 >H .9~7~):'~>(,l :~9i)8.4 DEC 613S>.0 :a:~4.0 4:?1B,:'j :I.I,::':':i ~•4 S''j ;.1 f>•0 :t.:H12:~,II :i bO(lS'.1 S'S'89.0 1:i,'iOH,6 JAN 1l7:W >0 ~~~jl)7>I):~~~j 1 :~•B ~.3 \"~!'j";0 ~~;S':t.Bi >::s J.:t.i'ln,"7 :I.t\.~:~~~>a 9:18:~>1 J.:!~jf,9 .7 FEB :1986.0 1731.0 :?'S'-'\(I,:-:l ?:~(;:~•~'j 8052.0 lObO:l,,",:i.:~40:~,~j B :l3:~,'I':t.:i.IH B • 5 MAR 38YB,I)2l):I.~5,1)~!b2B >"}:t.1/jO,,?'7 "j 'i '};.~•~:i ':lao '7 ,'}:t.~!~'j()H ,I)HO:~~)>9 J.()722.~:i (I F'r.::'i 109.0 2025.0 :11 -1:~.'Jl UHl?6 :If,'''9.-~c,'::;oo,():i ::~::!HL 4 7:",08 •.t\9820.8 r1AY ~'j ()~~o:~>l)H,~'\!:;,I)2~1Jl)9 >9 -16(;.t\().·,:t,():~9 II •:~:~<\a9H >~!1\~,~29 7 ,.~:t.O:B8 >t)~!.~~~17 .~; JUN :111073.0 :~S'31 :I .0 f,/l49~j.B B,',:··,;n,1 ,f,30S'48.0 -1nOl:i.:l '/:z.'/Ii'B !2 :W~:,",7 •~'j tl6:~:~2.3 JUL ~:l ():~;!>9 ,l)4B~'if,:')>I).~:5~~H~1 ,~6:~:'j:"ifl •'\:~'7 :~:.!:'5 ,?4mS:-S4 >.1\f,I)5 b"}>~'j ;-S,.,9~·j6 ,t).1\J.I)22 .6 AUG B21'47.0 '\::>118.0 f,6~):tO.~~'?:?H:1:1 .,~3/7:;~8.0 ·'?7f,Y,b f,::;:H n ,8 :~Tl:;>R.0 'l'7:1~iJ\.4 SEf':n 7()~~.l)~,H~jt)~~.t):1~!b~j,S ,().'\?H:'jl1 >:t.:to 'r,l,7:t.>:'j 29:1.Mj.7 44<)9'7 >:>2()9~!1 .1)29790.7 AfltHMi.::>7588.4 179::'0.'?~~:~5 ~.!~j •(~,:U~;,F.:~1 .9 18879.7 :..~:~~)~.I(l ,:~:U.~;iHB,tl :l.9061L f.:~:-S ~'j ~~H •0 $ f __L ......---~--=:--------'------::'"~/ HIBLE 2.~~1 IiONTHI.Y 11f1XHilIN,IHNHllll1r (;I,W I{E('l1'~FI.DMS AT SllfilrN~ POBT,-PRO)ECTHlHHH 11i~X PRE-PROJECT MIN MEAN WATANA ALONF MAX MIN MEnN I~ATANA/nFV11.Cr·lln'nN MAX MIN MEAN OCT ~;263\S.0 '.8026.1'~H)40:l.•()::)I,:"~(I/-,•:::;2()~67.9 3:n ;~:~.(I ::;:)~()7 ,(I ;,)O~'?(S ./-,3::'514.9 NO!,.':n ~j';:1 •~j ,l.,799 •~~1~!lN7.7 :~'1 :'j 4~.•~'j :J.:!.<},",".~1.<J:nl.1 ~~O:l.7:1..:~:I.2'17:~•<J l'79:J.~.3 DEC 15081.0 4763.4 H~~1:1..B ;~~):i.en •1\Utl20.8 1 ~/:I :I.::"•H 2~)"/I,:~(:l 11":3:?,~~:I"/0:t.8 .J(~N 12M;)9.l ,£,l)7:t .9 :19Mi .9 :!J.:)~·j9.b J.:!71/.<J ~.(":J.~Hl.1 ~~~~26 ...~) 9 '.2763.0 :1.7024.7 FEB 1:1532.2 4993.1 707:t.7 '.e;'B4B.'7 11:~99.tl :t ·173:!I B :?'(lI):~:"'.:I.:I:i.<1~?7,~~1~i949.8 HAR 'i'~.'):.:~.6 4'l:t.O.4 ,"~:~;..~.:.~:I./;?()1 •.3 ~.1 ?:.~\~t ~.j 'l :S:H.l >\~:l.79B6.S :I.1."95).t):I..~4~!.~•2 AF'F:9802.(-,:'j~'j~~0 .8 611'(;.7.:3 :I ('~:J(lf-,,;.''.(If:,08.9 :I :~321!•0 :t 1:8 :I.:~•(I '.()",~:)~.9 131>4"1.7 MfH 9·H II:;;':!:!YHt>9 .3 bO njO •~j 9l)7l)~:~•"J -:~?iJ:):'l,;.l.)579~SB .'1 (,1 ('l 6 '.~).:~:~:~6~~.S)~~~·jb2~·j8.1 JUN 17t,?1f.l.8 ~7838.0 124534.8 :l5H19~./;~)'1 <;':t I',•9 1 080::'(I •0 :t ~5 '7 ,}'1 ~,:l 57089.1 :106371.2 JUI..lbAH'.~.b 102184.3 :t32319.5 :tS1H02.0.YMlb7.:!U7·1~~~j.~j :t·<Hl{·I:t:~.'.9c)'.<J1.~~Ll."713.7 AUG :I.:q:.;:~:q •3 8()2~1.~,11'.997.7 :l274(J;~,4 ?/,(i:H .:';i 1 0325 I'•1 :t.:!(1"/(II)•4 "N,O:H •~j :I 02(;.41.9 SEF'1.(H~~:J.A .4 :i)9:~:~:I.•~~6,~ni~~.9 ~'9~!9~)>():~H.l9}.7 'S ~S ~~b~!•~j .1.I)t\:!1:-1 •1\:Hl:t 97.7 ,£,~Hl87 .6 ANNlI(~I.~:)'i'7()1.9 :";,£'285.1 ·18307.t,I":(\l.(\"J I":37024.2 41·}:H:t ,2 :5 1)'7()j,•9 :~I,'lIM,1>48320.0.J )\J 1 I ,d t 4 ';''-?',, '------L-- r-~--i~~~~,-':~=-.,.,--=-'~:~~,'~ .-;~-~~~~ TABLE 2.32 F'RE-PF:OJECT FI.0\·1 AT ~J(.:T(.:N{I (dH) 1-10 DXF l nJ Il'{J:lROL 0G'( YEAr~OCT NOV BEC JAN Ff.B ~I{)R M'R H(-1Y JUN .JlIL r:IJB REF'MIN II I'll 1 4i'19.9 :!I)a~~,,~1.l6~L 9 815,1 ,~41 .7 ~j69,1 681),1 1I6~j:),11 l.H~~2,1 191n.<l 16'113,6 n:!1),4 M18.1"3299.1 1.l O'J d 906.2 8011.0 673.0 619.B 1:r,02.;?u.6'I~'.t~IH:)17.9 H'786.b 164·"Jl~.O InO:L~j 7733.7.. 3 4~in.9 ~!171),1 1~;I)1.0 127<4.~;fl41.t)73:),(~(N.L9 4216,5 25773.1 22111),9 17356.3 11571,1)771b.746285.7.~!/56.fl 1281.2 8lfl.9 611.7 670.7 13112.0 15037.7 21469.8 j7355.3 166111.6 11513.5 803~'j,?""42:1.8.9 1 ~';,)9 ,,~llH:L8 11)87.8 al).~,1 6~~a ,~!942.6 11696.8 19476.7 .698~.6 21)421),6 '116~j ,~j 711)0.4oJ 6 3859.2 :.?O:H,l :l~49.5 138R.:<10~)O,:)81:6.1 940.8 \~7HI,1 ?'18BL4 ~?:~7117.9 ~?:7,:;:~7.0 I~H47.8 B719,~{7 41t)2,.~l~"iHH .1 10~HL 6 Hl,~;9 n·;4.H 694.'1 719.3 129S3,3 27171.8 25831.3 19153.4 13194.4 90:;1.084208.0 2276.6 1707.0 1:~n.o 1189.0 n~j.(I 945.1 1017~.2 2~27~.0 19940.9 17317.7 14841.1 8:~81109,t,O ~~'1 ,"I 29:S~i )';l ~!~!~)a )~i HSl).6 11)41.7 9l:L~)1~!M:i,4 9957.9 22097.8 19752.7 18343.4 ~j97S.7 ];'fl9.4103668;0 1729.5 111 ~"i tl HIBl.0 l/49.0 b94.q 885.7 10140.6 18329,6 20493.1 2J940.4 12466.9 8011,011:'i16~L ~:i ~!~!l,~.~j 16 n ,~~"14 t)I),1 l1~~S.Y 961.1 106"1,"1 131)44.2 1323J.4 1951)6,1 19323.1 160S5.6 7<J:-j 4.0126049.3 2327.B H'n,.;!177~'.9 1:~04.R 1331.0 1965.0 13637,9 2~784.1 19B39.B 19480.2 10146.2 ~:()(i2,'l 13 1\6,rl "t.,~!~!fl:S.4 176t).4 16l)IL 9 1~!~:i7.·1 1176.8 1457.4 I1JJ3.5 36017.1 23443.7 19037.1 12746.2 98:\2.9145560.1 ~!~:;08.9 170fl.9 1308.9 1184.7 B\:~~.I-,776.6 15299.2 2066~.4 28767.4 21011.4 10HOQ.0 lJ2f7.71""-:HH7.1 UWJ,l 1.l94,7 H~:i~!,0 7B1.n ~j7~j )~~,S09 .~!J5711.8 42341.9 20082.8 141)48.2 7~)~~4 )~!13~~62.7-, 16 4759.4 nMI.:~1070.3 B63.0 772.7 80'1.:~1232,4 1096~.0 21?13.0 232~5.9 17394.1 16225,6 8'151.517:··i~!21..~!l~ifl~).3 1~!O~.6 10M.4 9U4.7 '}("l-"7 I.B8.4 71)94.1 25939.6 1~153.5 17391).9 'nH.l 7:S74.4183269.8-j ~102,~~1121.6 110?~~1(,:H.3 8119.:"8~lJ,7 1255S.5 74711.9 11987.3 26104.5 13672.9 S'OS':;.7194019.0 n)~pl.~i 17l)4.~!1I-,J.7.6 1~'j,I.t).4 1~:i,SI)>'\1576.7 12826.7 25704.0 22082,8 14147.5 116:L 6 f!O:52 .2 20 ~q47.0 1~,6/,.(l 1073.0 884.0 748.0 bfH,.O 8~'iO.0 79~2.0 17~09,0 15871.0 14078.0 8150.0 ,,100.'~ 21 2<10.~,1.It)~!t),')709 •~~,t),~6.~!,S02,1 1>~!4 ..l YB,t.".\95J6.4 14399.0 10411).1 16263.8 n~!4 .1 6).14 .6 "'"3768.0 2496.4 H.8?4 UWI.l '?T/,4 71'7.1 813.7 2857,2 27612.1I 2112~t4 27446.6 12188.9 B:WH.:i4' 23 -1"1/9.1 2 ~-;a 1 •I)1'}~jl,4 1,t.,lt).9 14'Jl.4 1:~6,~•t)131)5.4 1597J.l 27129.3 19821).3 1750~.5 10955.7 fl~'b3.4 24 4301.2 1977.S'124f,,::i 1031.:)1000.:~Bn.9 91'1.1 nB?(l ~!.:~H:)lJ,~~If,3:lj.1 180H.7 8(IS'9.7 7:i12,O 'I "":~():';,t.,>:.;l~i:H.l 'nLb 7fl\~,1 Mi9."I 627 .:~fl71,')l:!BW).t):l<I7(N ..~1~j·nl.9 I~S~):!.L7 "Ii'fl6 •~!,qU.?.:-oJ ;!6 3088.8 1~7·1.4 1?76.7 1~!1 ~L B 1110.3 1(141.<\1211,2 11672.2 266H9,2 23430.41~126.6 13075.3 B402,7 27 :j 67'J.l 1,S 01 •1 sn.~!7:)7.B H.L~!n'N.7 10:'j'}.a B<J.1a.B 1999·1'.0 1701:).:~1839.L ~j ~j7J.l.~:i 6H~~4.8 2U 2973.5 1926.7 1687.::;13-18.7 1.~:!02.9 llJO,f!1~.)03 •-1 8569.4 Jj357.B 19707.3 16007.3 1061J.l B:?32.629:)i'9:~.9 26"(1~'j,.~IfJ7'}.7 1~)77.9 1 ~!,(,7 •7 1~!~:i6.7 141)8.4 112J1,5 17277.2 lU395.2 13412.1 7U2,6 6992.2 30 3773.9 1944,S'U1:?b 1136.8 1055.4 1101.2 1317.9 12369.3 2290~,8 24911.7 1&670.7 ~'(lW"7 81B3.731b1:'-;1),t),):'j2:"";.t):!l)~.;:!•t)Hlt).0 L!~~,~.t)117'7.0 141)4.0 11)141).0 23400.0 26741).0 InOOt).O 11(1)1).1),8'1'07.9:~~t.45S.0 :S~!97 •0 1385.0 I1t\7.0 .~'?1,(I BBS'.(l 1103,0 10406.0 17017,0 27840.0 J1435.0 12026.0 S':HIO.4 MAX f,4~Hl.l),·i~)?~.;i ()2~~~·;B)~i 17'n.9 l~jM .4 1~·;60.tl 1965.0 15973.1 42841.9 26767.4 31435.0 17205.5 9812.9MIN2"03.1 1070.S'709.3 IS:~6.7 f,(,;?•1 :)6S'.1 &09.2 2857,2 1~233.4 15871.0 13412.1 5711.5 b 100,'~ilF.MI 4~;~~2 •6 ~!O~·j9.1 1.<\14.11 l1.S~L :")911.".~898.:i 11)l)9.7 lO:S:H.·l nll?,,7 2tHHt),l'l116?B.:;11)792.0 aon.o I 1_.-----:----,~. ----- ~~-~-' ----..,.' TABLE 2.35 F·OST-F'RO.JfCT now Al rlEVll r;{;N)'('Il~(I'ff.) 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};,llj\:~,0 912:1.8 $ .\,,"., ~--'---~"- r---J-_-'---~--------r-~ ...----r---,-'., TAI:LE 2.38 F'OST""PRDJECT fLOl~(d f;lJl-H;HHH~\cf:=,) \·h.lMIr\!nE'JH.CMIYlll-l t CMiE C YEAR OCT NfiV [IEC Jr.:N FEn 11M:.;f'r.:1M Y JtlN ,1111.(;til;SEP MH!\Ia 1 I1H47.2 13990.4 14750.2 IJ371.3 12427.J 10172.3 H'JeLO UI:,!~~~~.3 :~;Ll'n.•9 078:).1 ·1/I~~/I·:?()2H?:U.O 'n,,~,95,3 ')151~A.5 1055~.1 1083~.9 946'1.t.8139.(',H(l:~:).9 9081.6 36890.5 ~16J7.1 5~6)2.1 ~~6U6.0 3~129,O 2,1i BO,~,I f.L 3 l1<JHLI CDll'/..l 14:'j~·jl).a n~j'l,~.'1 ,1.:!b':JL6 LU,U.6 lr5 9.3 12034.0 4b163.2 1~4~8.5 14443,0 26877,0 ~~:.!1 ~"·1 •:~4 16499.415352.3 1504H.0 13407.t.1?7~~4.i.:l14liO.O 10fW.c1.8 4~~:~lll.:~,·HIB:H,6 "1~I,)(l7.1 41344,0 ~!/71..7,(I ?;~/q:t (:'~5 14874.7 1023'1.7 14J7J.J 1J632.6 12a~8.8 10562.3 'i'1i(j,~,:~~!7UI:Ll.0 2~7:'il"l)~:UH 3 •~5614104,5 10972,2 1~007.4 :l391~.4 13100.0 12013.0 9260.8 lY5Y(I.2 -1Y~EJ.O 5222S.~63942.0 31539,~2~:j~:i:r:'),>' 7 139'12.9 IJ590.8 144J3,1 IJ~57,2 i22b5.9 10349.3 IlfJ<l f>.fl ~!7 Olll.:";:·):,~:W.L~!l.i)~j,S 7•~s ~ifl J.n •';J 4·1 ~9:)•$~!7~)~~8 I'.~ 8 18233.9 15~~2.A 154~B.l 14027,9 13219.3 1'102,6 10540.8 ?l!9~6.0 60408.3 ~612~,1 4~703.0 J849J.B :~():)~j("7 9 21170.0 16926.8 lA009.1 13891.J 12a96,9 1187/.6 I1JJ1.'2311b7.2 44279.2 1J952.1 ;b362.0 2184H,0 :·!.3?·~t 1.,)10 13883.3 10411.1 107.t.0.8 1l932.1 13038.8 104:19.3 9491.8 ~41Y/.6 4YJ8B,7 50470.4 535~1.3 J4~~ll.0 2 ~:~;;:;:.~11118112.9 15142.0 15372.7 14018.9 IJ029.1 11917,3 104a4,2 29252.9 30357.5 42508.7 4J725.0 31876.0 ";!~~!)/.:..11216405.6 13856,3 j569~.7 1433~.B 13176.8 1~274,?1?218.4 ?5~7E.2 44071.2 47906.7 50516.0 32001.0 ?/1 'j'~,~:;\,}D 15736.8 14019.9 15400.9 14023 ••IJ076.2 12007.7 11076.0 192113.5 57265.0 509J7.9 551A2,5 30711,0 ~!b--1~.;8.;,14 16937.9 14~R~.8 15270.8 14170.5 13402.5 11755.3 9527.7 27126.1 ~23~3.1 55208.6 41268.0 2R'12.9 24:·;,.l.:("'1 R1521536.9 151JO.8 14637.7 133fl7.9 12672.3 10152.3 ilYfU.a 10:Ull.0 l.rn:L 2 .:\~;2~·i~!.2 4l9~S L ()::~'h''}f"0 ~!-':~~"'-.4 t ..1161\~4li],8 U8t.8.6 15812.2 14014.1 U9~1.R 1(l9~)7.3 10037.B 19:~n,(1 ,1;'011.9 4(dlll"t 4n:)~j,O 44997.5 24~)}1,::: 17 211H9.<J 14544.8 15022.7 1:1742.9 13002~~11522.7 10200.8 IJ951.0 49519.5 4276J.5 5217/.0 27706.0 :.!:~}.:.::8 t J1814319.1 9907.7 10527.5 :1:1895.8 13273.8 10932.3 9~~1.8 27500.6 48006,1 60166,3 6531B,G 37~7Y,0 ;~C.tl ~:;;l ,~~ 19 13687.9 14493.0 15245.1 13951.6 133116.9 12508.0 11167.6 314~J.l 57296.~~J786.9 41560.()21369.0 (~~)1.:q3 f U 20 13141.t,975:J.f,9989.0 :10380.6 11710.8 10161.3 9(/44.8 18111(,,:)]:)I)1<,',}:1(W:),~.O 311MS.('l 24:~:~6,(1 .t 906B.,.., 21 U2U.1.'/9 7 ~-;..~.I.1)1 }flo I nlU.l ll~!n •'I ll;~'lS'.'\9647.8 21053.0 36932.0 15953 ••4b946.0 27370.0 ~~()l".1 "2 ~•~~. 22 14491.1 11784.7 11140.2 9:)80.1 8133.9 8170,9 7508.4 13~68,9 ~197~.2 47~H7,4 ~4609.0 2H014.H ,)")1';<':-",~) ,,:.....1 I,..I ,.n 1129,1.9 1~;n,~.7 1~)l7"1.1 I~HI8:),9 U179.1 1~!i)92.<J UO~;lL8 :n/ill).t)'l:i:n:L::!,1:1984.(;<):'l'I\~LO :HO~;,L.>\).~:.~~:~~')t:•t; 24 15215.2 1479~,1 '5106.9 13731.5 129~R.l 11175.3 S\4?:L~)1600(l,S'404U.7 ;'\S'9·1::j.O 4?~11}~i.0 2~"i4t,.1.0 214'79.02:5 14371.4 1027<J.9 1053Q.5 94~H.9 Bl'19.:~Y~j97 •H ~;~i.lfl.O ~!:'i917.~;.:sn/;4.1 3YV:L9 :~91)1)2.i):~,~l.~LI)),9i>9.s,\~ 26 15412,9 10438.1 10442.7 9t.6~.9 82.\t.•7 R?~:'II.4 75::;t.•5 nS1J,4 :'i~~4 ''ilL -1 ~IB4 (,1}Ill,4::i::'B8.(I :~8:=;:"7,(l ::~~\:l13.0?7 16353.6 13461.8 14195.2 12973.0 12JJ'.8 10120.3 9896,H 10144.9 39997.2 1J050,0 t4J~5.()20921.0 ~!11J.8.1 28 13747.4 10753.6 11373.4 10:109.6 87(19,1 l<'B~:i.6 10US'.8 n79:L::;r}n~\~j,O 41lS':)~!.~j 4;'917.0 2'i37S'.0 ~11\J(18.~:i 29 17184.7 14904.3 155J2.2 13991,6 12899 ••11912.5 11333.5 17743.4 J5206.7 4~~72.J J/728,0 2J433.')·2 J.:ij~:'.t..t Sl3013S06.6 10552.1 10899.3 98~i9.1 850,).6 8381.1 9,q9,~:;;W::i?H.:~":H(/:~.~):);~fj(n,l '1(l·1~~7.0 2:";J?(I.(r :U t,nO,9 MAX 21536.9 16926.8 16009.1 143J2.8 IJ402.5 12508.0 1221R,Q 422117.3 73799,2 60567.5 65318,8 44997,~n:i8::'i.4 tlIN 13141.6 97~:~,6 9989.0 S':183.1 R13:"L9 803:\,9 7::·(18."\1<d:'\ll.(l :H'~'::,i,.5 3H:'jf,.(l 37nB.o :~(IS'?J.(I .l 'i'(I/.n,i,MEAN l~j8,~8.7 1:!948.4 DI~l)fL6 1:!~j,~9,1 l.lfl.l.H.:).ll)}n.:·j 9020.9 21217.5 46332.3 47622.6 47151.4 29790,1 :U:H~1,0 $ ~J __1-, --'- TABLE 2.39 POST-PROJECT Fl.ml AT SlJHlTlUi (cf!;) WATM1M))EI)H,CMf(I)U ;CM;E C YEAR .OCT NOV [Ifr.JAN FE I<"1M.:flPR 11("Y .IIlN .IIIL r..l.Ill fin',;I!/-1l J,'\1 1 27713.6 1971~.5 17336.2 16693.2 15406.9 13516.0 12259.7 62107,0 119194.6109475.9 99551.8 40330.2 4.~/?2,9 2 20926.6 12773,9 13015.8 j3611.2 J2998.9 12273,4 12815.H 53967.0 68019.7107302.5 93276.9 615~1.~1j04:';3,6332320.7 24050.9 17757.3 IH401.2 11217.0 14332.6 12587.9 46070.JI09972.511U833.3107266.1 76896.3 4'jl:Hl2.8444057.8 24442.4 20714.0 18658.3 1716A.l 15512.8 14595.4 00825.3115310.9112525,3 89000,0 38197.7 A'i'~,:'6,4521816.2 16976.~15667,9 11217.6 14972.9 13119.0 1290H.J 53106,~92716.410J528,0114496.7 6265~.3 ~~j 'u,2 •1625812.2 13800.0 16877.4 17?43.0 157~6,1 14751,6 13015.2 55996.2j49315,Bl~0210.8106370.049658.6 5(1~"',.l,372~!90:j,,~197 'I~j •7 1l1~j.~6,a IM124.4 1 bU 11),,1 1 4~6;L 7 U7a~j.i)7b ~O 1.:S.l-'lo~!al:':il48~H:L 1J.~:i)70'1.4104'~.1.B.~~)'I}OI.9a44803.5 30171.3 24687.4 20622.0 1813~,4 16611.7 15339.1 5HOI0.41~747~.11241~O.4116?72.978197,8 ~)ll(lI1.9955407,0 27701,4 20505,4 173H5.~Ib~117.H 15913,4 160Jl.0 ~6~2H.7 Y6~24,OI06JH2.~89068,5 51803.3 ~la:.'~)7.41032848.4 14608.5 11432.2 16340.7 165~4,1 13804.8 13070.6 51339.0 95705.01~9166.~j19937.6 6~5H~.3 t\Bl;3 ~~.(J112Hn6,O IHIl9L:'j 17:m4.~{16676.,~II>CS;l.l l<\H'i.Li'l~nll~j,fl 4<I:H~!.~j 1:HHt),91D68B.uon:11 ,,1 7i):S::,::;'1 "-1:"'1':0.21233191.9 20661.5 2J960.922262~9 1973~.8 17986.8 16912.0 i'H9Y6.9134900.31~~735(7106596.~58434.3 :)''1 'J'I"~•:~L~30186.5 20406.2 19557,5 18851.5 15916,7 1498J.3 1~IJO.2 49J17.3132777.0126623.2115202.0 74R06,~:;}';'~6,?14 30698.1 19287.3 194~5.4 18767.2 1763~.1 15414,4 13067.4 45704.3 71362cOl~3409.7 Y5036,8 7('013,3 I~~I?:'~.4I'·40828.2 20925.4 16730.7 Ib942.0 159116.9 13041.7 1213J.6 37229.2115051,611\222.0 81839.5 45HJ~.H ·1·17::;7.~;.) 16 29761.7 168:).1\.6 1740~!.B 1759:-1.0 1617~,t,H3(IY.2 Lon,s''\.4761.·1 9;'~i9B.;'jl~'7~):i,?:io;~n~'j.9 B123f:l,8 Irl·~y.;~4 0 17 .~9:B:)'1 21 :):~,~•.~20?17.0 1a:~,t,'J.7 17 'Ill 2 •(.J 1:'in(L ~~Q6:H.l ·:191il:L 41 O:H ~s:!•:"1.1.O:H n •91 OBH?'1'.:~t,1 4:P ,:s -:~H.\H3 t /.,18 29164.3 18575.3 14993.4 16226.3 17705,9 14822,5 138113.4 ~269S.21167~:i.011YJ~7,6119H89,B B9~?7.0 5;~.t60.01940/1),L,,4 249 '\~!.8 ~!:j76.L 1 ~~D7 <l ,8 ~!I)'/:n,1 1T'W:!•i)L~:PL~!:Wt;!~j,~I.l J.B~19:L~!.l1·I~jt,:L 4 lH1I).L:)1:!:il,n.a ~i.1.~sn8.~'20 289·10.1 163~i9.0 1395~.5 14t,1::1,6 1614 3 d l:~,~74.b 12714.8 ·H"8B,:)94~\(l("91(1:~nll.9 ','21:)4.(l 57n:;"l,·1:Q I"},fl21:-~64 a l),:")"12796.6 12.H ,1 •:'j 1~!iJ ~j 7 .:~J.1<\n •;.!II ,S 99 ,()J.1~!l>6 •'J '\!1 <\O~!,:!1I:),):1:!•"t .t 111 LS 7•111)Y/4 a II):i.>'?',~L :J 'I ~;;,,13 •2')')35044.4 20924.9 14B43.4 1276J.R 11873.7 11702.5 106~5.9 3~626c2 98023.4121983.8113100.'~1631.0 1':"(',1°.'OJ .,~.... ,I}/\},}c.:.~.~35745.123JI3.6 19042.9 19008,6 170J6.4 15403.7 14743.7 ~4552,0154~IJ.71294711.810d3d6.657120,':)..1.:\:j i'•12-1 28409.1 23630.0 19?24.0 jB02~.7 17490,8 14841.9 ]4291.0 2319.9103275.81]1596.2 98970.8 4~~S2,8 'I i;.{,'l.~•82524063.1 15694.2 13097.5 IJ951.5 1~421>6 13671.5 IJ565.6 550119.3 57089.1 90191.2 76031,5 ~31JJ.5 :~\!,:'~~6.62622630.9 15900,1 16084.7 14715.9 13030.7 12466.4 11263.5 4j677.410A41?61jB417,6 B5270.1 707J(,,1 Jl1Ji)~!,:{D 32339,6 19156.8 17451,2 16995,0 15593.8 13507.3 13~55.H 1>51JO.O 90631.~1027~••1 91350.1 51329,0 '1q~)06tt:,28 33267.4 23135.6 191811.4 15978.6 13980.1 1441lB.6 12835.8 516HJ.~110522.313065n,511R~60.180~JO,1 51j7M,.1 29 38015.7 20404.3 17748.2 16755.6 16443.4 1~500.5 14824.5 43706,4 lU092,110J242.4 97710.2 56193,0 :1:q·19.03039093.6 19904.1 j5397.3 15008.1 13246,6 12450,'14398.5 7591?13103~5~.512~623.1119J10.072870.0 ~~~'1.1J 1'1 MAX 55407,0 30171,3 25163.1 222~2.9 209~3>1 17136.8 16912.0 88615.31514/4.1148"13>lt20709.4101~18.~:')'1/01,9tlltl20926.6 12773.9 11432.2 12763.8 11427,2 11699.0 106~5.9 32626,2 ~708911 90191.2 76031.5 38197.7 "'~6i'H\~,';MEAN 32514.1 19912.3 17701.8 17024.7 15949.8 14~26.2 IJ644.J 5625".1106J71,211A7l3,71026~1,9638H7.6 ~:P.""O ,0 $ ~, ,L-~-----'_.~"------L--'----~---- IHlJ()(NUU 5~UHG C\fOO 0200 O:lOO C>4O() 0:.0<) 06:Xl Df.TA COLLECTED •STRE fLDW·CONTINUOUS RECORD o Sn<£fW..· -N<RlI"L RceDRD •WA.TER QUAUTY T ",UER TE ...f"EMTURE ..SEDI ENT DISCH ..RGE c:>CLI TE ,"PPROx.1 NOTES Z.CONTINUOUS WATER QU ..LITY MONITOR INSTAlLED 3.DATA COLLECTION 1981 SEASON ~.THE LETTER BEfORE [ADi STATION NA"'E IN Tl<E TABLE IS UsED ON THE ....P TO ....AX THE APPROXlloUTE lDCATION OF THE STAlIONS. ~STATION NU"'BERS UNDERLINED ...ottJrrES Dl>.T..COLLECTED ~BY STU9T TEU'IN 1980-82..SNOW COURSES "EASURED -ARt:NOT UNDERLINED FOR CLARITY. fREEZING MIN AND INCl.OUD ICING 0700 SNOW COIJRSE 0600 SHOW CREEP 0900 SCALE ! !' I! \ I \ t, x x x X x x ]( lC lC lC lC X lC X Il lC IC lC X lC lC lC lC x x lC ]( lC X Il x OllU STATION !;;: I ..)SUS"N"RI\I£A NE ..R [l(N..U 181 SUS'TN"RI\I£R AT YEE e;.t.NroH ICI SUS,TNA AI\I£R HE4R W"T"N"DO ..S1T"t IDISUSITN..RI\I£R HEJJl [l(VlL CANYON 1[1 SVSITNA RI\I£R AT GOLD CRU~ .,I CHUl (TN""'YER HEAR TAl.~f:£T"" (L I MCLAREN RIVER AT PAXSON IG)Tt.L~UTNA RMJ\HE"R TALKEETNA h<l SUSllN"ftlVER HEAR SUN5'<'NE III SKWENTNA "I\I£R HEAR S"..[on .... IJI lENTN..A-y£R HEAR SUS'TNA SUTION I..Sus".....AIVUl AT SlJSf1H.SUTION _~"_~_~.~_----:__---=-------:-~:-:-:-::::=-=~---=---~--------.-:F:...:I:.:G:.:U:..:.RE=-=E.:....=-2.=-:"1:.J PAL ..ER Qo 0681 HEALY E>Olin0li7O e AHOiOR ..GE 0 .....' DATA COLLECTION STATIONS 06ne 08~. coot<INLET 1 ) .L1 '~-~~ Susitna R.near Denali THRFE PARAMETE~LOG-NORMAL DISTRlnUTION-wtTH q5 PcT (1 PARAMETERS ESTIMATED f\Y MAXHllJM llKLlHOOD IOf5----------------------------------------------------~-------------------------_ I I tit I I I I I I9------------------------------------------------------------------------------------------_ I I I I I I I I I I I I I I I 1 I I I I 1 B -----------------------------------------------------------~-----------------------------------------------_I I I I I I I I I I I I I I I '1 I 1 I I I I 7 ---------------------------------------------------------------------------------------------_ I I I I 1 1 I I 1 1 I 1 I 1 I I 1bJ_---------------------------------------________- - _ I I I fil I I I 1 I I 1 I 1 I 1 I 1 I 1 I I ,I 1 I I I I 5 ----------------------------------------------------~-----------------------------------------------------------lit 1 I I I I 1 1 I 1 I I I I I I I I 1 4 --------------------------------------------------------------------------------~----------Itt I I I I I til 1 I I I J I IIIII 1 I 1 I 1 1 1 I 1 I 3 --------------------------------------------------------------------------------I I I I I 1 I I I I lit 1 1 I til I 1 I 1 I [t I I I I 1 1 I I I IX I I I 2 -------------------------------------------------------------------------------------I I 1 1 [ I I 1 I I 1 1 1 1 I 1 1 [ I 1 I 1 I I I I 1 1 I I 1 1 1 1 1 I I I I I 1,I I 1 1 I 1 1 ~x I I 1 I 1XII I 1 1•)(I I [ I [ I I 1 I I 1 'I 1 I I I I 1 I I I I·1 1 I I 1 [1 I 1 1 1 1IOf4----------------------------------------------------------------------------------------------------------------------------1.005 1.05 1.Z~Z.O 5.0 10.ZOo 50.100.200.500. RECUR~ENCE INTERVAL IN YEARS X--OASERVFD OATh O--FSTIMATED DATA *--951 CONFIDENCE LIMITS ANNUAL FLOOD FREQUENCY CURVE SUSITNA RIVER NEAR DENALI FIGURE E.2.2 ,--_--1 :::-:~ 1 --------------------------~----------------------------------------------------------------------1 I I I I I I I --------------------------------~---------------------------------------------------------------------.1I• 1 I ----------------------------------------------------------------------~-----------------------------------------------I I I I 1 I 1 ·1 1 1 1 I I I 1 I (, ') ? "I ~ '1 ;~::::::::::::\:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::--- 1 1 1 I I J lit------------------------------------------------------------ I I I •-----I 1 I ~x I I I-------------- I I 1 I I I 11 f'• 1 :;USitll;1 K.UC:1C Cllntwcll L"(.-r:0 ~~.AL DI ';T~1n 'J T1011-III TII 'l'i PC T CL Ir~,;----------------------------------------------------------------------------------------------------------------------------... ?----------------------------------------------------------------------------------------------------------------------------1 I I I I I I I I I I 1 1 I I I I I I I I I I I I I' I I I I I I I I 1 I I10f3--------------------------------------------------------------------------------------------------------------.-------------1.005 1.05 1.25 2.0 ';.0 10.20.SO.100.200.500. RF.CU~RENCE INT(RV~L IN YEA~S x--OOSERVEn DATA O--ESTIMATEO DATA .--95(CONFIOFNCE LIMITS FREQUENCY CURVE RIVER NEAR CANTWELL ANNUAL FLOOD SUSITNA FIGURE E.2.3 ~-- .__L Susllna R.at Gold CreekTHRFEPARAMFTFRIOG-~OnMAL OISTRlmITIQN-WITH q5 PeT CLPARAMFTFRSFSTINATFDAYMAXIMUMI.IKLIHOOO10Fb----------------------------------------------------------------------------------------------------------------------------~---------------------------------------------------------------------------------------------------------------------------- B ---------------------------------------------------------~------------------------------------------------------------------ --~--------------------------------------------------------------------------------------------------------------------------~-------------------------------------------------------------------------------------------------~--------- I I-u------------j------j I I _."--O--X---:~~ ------~-----------4 -------I ') I>-----~===!=====!======!======!___________________________!!I I I I -------------------- _---------------------------------1 I I I I-----~------------------------------ 3 l---------~~-x ----------I ----•••Ia---------x 1 ~I·I I --------------------------------~I I I III1I I I ~I I I I I I 1 I Z I I I II-----------------------~----------~--------~- I I :I1,I I 1 I ----------------------------- I :!I I I I I I I II1IIII I I I I ,I ,I 1 I I I I I I 10F4--------------------------1 I I II I I , I1.005 1.05 ------i-Z5------------------------------------------------------------I I I I,--OASFRVEO O'T'•REcuRRENCE INTERV;'OIN 'E,RS ',0 10.20:-----,0:---,00:-,00:---;00: 0--E5TIMATFO OATA---951 CONFIDENCF LIMITS ANNUAL FLOOD FREQUENCY CURVE SUSITNA RIVER AT GOLD CREEK FIGURE E.2.4 -__L "-';;...---==;- MLclaren R.ncar Paxson THRFF PARAMFTER LOG-NORMAL OI5TRIP.UTI1N-WITH q5 peT CLPARAflFTfR5E5TtMATEORYMAxt~'ml I.IKLlIIOOO IOF5---------------------------------------------------------------------------------------------------------------------------- q ----------------------------------------------------------------------------------------------------------------------------R ---------------------------------------------------------------------------------------------------------------------------- 1 I------- I I I I I I ~---------------------------------------------------------------------------,------------------------------------------------------------------- t b ---------------------------------------------~I 1 __ ~------------------------------------------------------------------------ 7 l ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::~:::::::::::::::::::::::::::::::::::::::::2_ I lIt I t I 5 ---------------------------------------------------------------------------------------------------------------------1 lIt ttl I t 4 ~------------~------------------:--------------------:--l----------------!----------!--------!---------!-----!- 3 !------------!------------------1--------------------1--~----------------1----------I--------J-----~-------------- 2 -~------------------------------------------------------.----------------------------------------I t I I tIIIIIII1 I I I I I 1 I I 1 I 1 I I I I 1 'OF4i------------I---------~--------i--------------------i-------------------i--------i--~ ANNUAL FLOOD FREQUENCY CURVE MACLAREN RIVER NEAR PAXSON FIGURE E.2.5 ;------L_ Chulitna R.near Talkeetna THREE PARAMETER LOG-NORMAL DI5TRIAUTIQN-WITH 95 peT CL PARAMETERS ESTIMATED BY MAXIMUM LIKLIHOOO IOF5------------------------------------------------------------------------------------------------------------ I I I I I I.I I 9 ---------------------------------------------------------------------------------------------------------~------------------I I I I I I I I I I I I A --------------------------------------------------------------------------------------------------I I I I 1 I I I I I I I I I 1 -------------------------------------------------------------------------------------------------------I I ,I I I I I I I I t I •I t I I I b -~----------------------------------------------------~----------------------------------------------------------------I I I 1 I I I I I I I I I I I I I I I I I I I'x I I I I 5 ------------------------------------------------------------------------------------------------------I I I I I I -\I I I I I I 4 -----------------------------------------------------------------------------------------------1 I I I I I 1 I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I t I 3 n 6 c ~----------------------------------------------------------------------------------------------I I I I I I I I IIIIIIII I I I I I \,I I I I I I I II I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I ?----------------------------------------------------------------------------------------------------------------------------I I I I I I I I I IIIIIIIII I I I I I 1 I I I I I 1 I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ,1 I I I I I I I 1 I I I I I I I I I I I I I 1 I I I , I I I I I I I I I I I ,I I I I I I I '"I11IIIII I I 1 1 I I I I I I I I I I IOF4---------------------------------------------------------------~------------------------------------------------------------1.005 1.U5 1.2~2.0 5.0 10.20.50.100.200.500. RfCuRRENCE INTfRVAL IN YEARS X--OBSFRVED DATA O--[STIMATED DATA *--951 CONFIDFNCF LIMITS ANNUAL FLOOD FREQUENCY CURVE CHULITNA RIVER NEAR TALKEETNA '-r-~~__ FIGURE E.2.6 ~~-- I .-----_! I I I, I, III I 1---------I 2 Talkeetna R.near Talkeetna THREE PARAMFTER LOG-~ORMAL DISTRIBUTION-WITH 95 peT CL PARAMETERS ESTIMATED BY M"XI~\llM LIKLtHOOO10Fb----------------------------------------------------------------------------------------------_ 9 ------------------------------------------------------------------------------------------_ 8 ---------------------------------------------------------------------------------------------------------_I I I I I I I I I , I 7 ------------------------------------------------------------------------------------------------_ b -----------------------------------------------------------~------------------------------------------------_,I I I I I I I I , I 5 ----------------------------------------------------------------------------------------------------------------------------,I ,I I I I I I , 4 ~------------~------------------~--------------------~-------------------~----------f--------i---------f-----~------~--- I I I I I I J I I 3 -----------------------------------------------------r------------------------------------------------------------,I I ,I I I I I I ,,,1 I I I 'I I I I I I I I I 2 ----------------------------------------------------------------------------------------------------------I I , I I I I I, I I 1 I I III1IIIIIOF5-----------------------------------------------------'---------------------------------------------------------,I ,I I I I I 9 --------------------------------------------------------------------------------------- 8 ------------------------------------------------------------------------------------ 7 ---------------------------------------------------------------------------------I I I 'I I x I I'I b -------------------------------------------------------------------------------X---------------------------------------I 1 I I [I'1 5 ------------------------------------------------------------------------------------------------------,'I I I ,I 4 -----------------------------------------------------------------------------------------------------1 I I I I 1 I I I I I I I I3-----------~--------------------------------------X--------------------------------------------------I I I I I'I I I I I I l'1 I I I I I l'1,I I I I 1 I I--------------------------------------------------------------------------------------------------I I I 1 I I'1_____-jl.-~I I I I I I , Il I I I I I 1 I I I 1 I I I I , I I I 1 I I I I I I I I I I I I I I I ,10F4----------------------------------------------------------------------------------------------------------------------------1.005 1.05 1.25 2.0 5.0 10.20.50.100.200.500. RECuRRENCE INTERVAL IN YEARS X--OBSfRVFD DATA O--F.STIIIATF.O OATA 1l--95'CONFIDFNCF LIMITS ANNUAL FLOOD FREQUENCY CURVE TALKEETNA RIVER NEAR TALKEETNA FIGURE E.2.7 r-___ Skwentna IL near Skwcl,tna THREE PARAt-IETFR lOCi-NORMAL nI5TRIPIJTlntl-WTTH 9'i PCT C"LPt>RAMFTER5 E~TII<\ATED BY MAXIMUM L1KLIHOOO10F5------------------------------------------------------------------------------------------------------------------_ I I I I I I I I I , I 9 ---------------------------------------------------------~------------------------------------------------__----------------I I I I .I I I I I I ,I I I I I I I I I I R --------------------------------------------------------------------------------------------------------------------------I I I I I I I I I I I I I I I I I I 1 --------------------------------------------------------------------------------------------------------------------------I I I I I I I I I b ~------------f------------------i--------------------~-------------------~----------~-------:---------~-----~----------~ I I I I I I I I IIIII'I X I I I5-----------------------------------------------------------------------------------X------------------------------------I I I I I 0 I I I I I I I I I I 1 I 4 :::_______________________________I :=~~~----~I~-~-~-~-~-~-~-~-~-:-~-:-:-~-~-~-~- I I I I I ( I I I I 1 , IIII I I I , I I 1 I I I , 1 I I I I I I I 1III I I I , I 3 ----------------------------------------------------------------------------------------------1 I ,I I I I I I IIIII I I I I III,I I I I I I I I I I I I I I I I I I I I I I , IIIII I I I , IXIII I I I I 1--------------------------------------------------------------------------------------------------------------I 1 I I I I 1 I I I I I I I I IIII I I I I IIII I I I I IIII I I I I I 1 I I I I I I IIII I I I I IIII I I I I IIII I I I I IIII I I I , I I I I I I I I 1III I I I I I1I,I I I I 1 I II I I I I I I I I I 1 110F4----------------------------------------------------------------------------------------------------------------------------1.005 1.05 1.7.'i 2.0 5.0 10.20.50.100.200.500.RECURPENCF INTERVAL IN YEARS X--ORSFRVfn DATAO--ESTIMATEn nATA *--95t CO~FIDEN(F LIMIT5 ANNUAL FLOOD FREQUENCY CURVE SKWENTNA RIVER NEAR SKWENTNA FIGURE E.2.8 ,--=-=-.-_...~~_.------'-"-~---~~~-----.,----..-,--------I ....:_~--J T~ -}i. -"1"1-t 1--'-~I • I .._•••.--l--I--.J.:- ,;1 1 111\N-O'~E'.'WI 11111 .-'1';'1 1"1'-'11'"I7.0 .'---J:11 1:1"I:J+'-II!~~:;lA~:"'~:.~l:-9 -.)~:1-.<:_-~_:~r ·lj'J:.~.-.~;.-_~~l~::'~,··}:'I"~':E~::·~~_~,~ll'l ::,I-'~·~~. 6.0 ".'-'~F-=R~rI W ._'-_----,--::~:<:>~='-:::)1 ,,:~~..:--:,:'i --:.~:-~, I I II'L I I 'l ~0"",II ,!I,,,.- .-11-'rd i ,··'~~-p:$!5·t~,'A!.~,:'1 I-:~~'~~~('1 :.'~'-.:.'--I 4 '1259'-J~~:~~..11.:.:"'-':-:='::':'I ~,:r:r':- 5.0--I 'I'll lt ~-,;',I!,'-::'-''-,_:.;,1"-'.-,'~~:,':".'~:".:::="","1 :~:::::::i~::'.;"-'T''11 1+:wi1~E:J,.:.':--','.':',..I''::,:-:I'-::::':-':""::',':·1 ..''_:'·.:':.:~·":-I I..: 4,0 >,:l!ll-:~~'.~~I~'~:I:':.I.l~'~:-~':_~:,,:".f ·,:::::<~..:·:'·',.::<'i~t:?L,~':<-',~:~~~~::~~~~.tt·._1!~: - -T j':!1I I-O.GJ:$p·-OR'h~~~~¢.-.T.,.I ~.-0 ,-:','I;J~- ,:.~,~'..~:~::::.:-:~:,:',:~.':I?~-:fill:.·I~l~~ i I 'j '~Ii"11 -I ,,,,-"",....- '..-.:----~.:-'.:',;:..:".,-::n p:p;....-c 3.0-_+-._...;....,.-1-1--1-4\_~':~.'-~'.,'~:"'-~II'"-.'-,-::.::'':=-:"-~:::::"~."-'.':.:::,., -1 ..1 :.1:M.n:-.--,~dji'~.bit'll:>I .'1 '.'''.:.:::-~.-,,':,~.._:::-::.---,:'::-::-.::-~-.-'rrw s:~,-.-..,...":.""..-.:.:--~I=-..:':1.:.12 '.=-..-- 2.0 :±Ullin'-"-',=-=~:::.:'..',--:,-::,'.:".,':--_>:~~::F.f\ii .'._::~:t::~t;:?::.-~,..:~~~:~.•:~:~~~. _jjJII '...-.=,,~=~~--"~:-·:.l-'~':1':-'-~-·If·-,-,~~.~"'''v~.-...,-~--~--=-==-=t-=.l-I~I-ul-..---,._.:..-..:---":-·:·r :,.-~-:=-..-'.'.-:.~~-~,--,-I----::--:w>0:: :J U~II II =::t~1~f''''L.-I :l~~;~i¥c ,IH1 L .r ~E:-'·:::·:;'i·..};~~~!)7}!j;!fUH -0.6 -=tiC-'-IiI V .'f r -I r ."...' ,~k -I~rrl .'::-:-o 'I "",~,,<''-:'",-I .:..::.,.,:..::::..",'' ,, I I ".,--:::-7-:-"!-Httt -~-'-:-~-':":..'c'-·':·-:t··7'__.'-',-::_':_~~~S'"'r:-::::";-:rll·',,~r.- 0,5 '1 lll"l'i-!M-··~~·"I-':'·:,,-'<~"I.''''':'~'>::I -~,:-:<:~>~:';:",-:1,l~~!':','.. -'"-,II .-,'-..-...--.- .--'.I"-."." .-..,-.1.'11'........-...,...11'1·-'-1--,1----lli .,, ,,..I',, ,......".,I ,..,I".,.\~:.',:.-, '-,.-.':,-;':..~.-:,:..:::-:.,':,:'..It~t I+"1-·°4 ,--_._..~:.--.-,..---,-. - -",--,...','" .'r-i+. -.-,\;.-.-'-'",.:' .t1 I'If'~~-:,--"I'-',:::::,'r II''-,F--r.-l:-_I'?;".::r:~~<.:_~-'...-,l·..>-:>..::_;'-:I~~'.-._-:.~~~:.:~q.",'.- -,"fi '-""'",-.-.r .-......-.--..,-".[=.IIII -l°3 ...''"..".-......,- -'--..----,...-,~,"r-=1--'.I !-....,,,...,..-..,.I . ,',', ::.'.I ·0.·..'..-.:.:.I ._-_:=-. . _I I -i_..-"I -_._-,-"-,,..11--,II It --,I 11 ...-+..,-1---II -'--I rm -', 1.005 1.05 1.25 2 5 10 20 50 100 200 500 10,000 RETURN PERIOD (YRS.) DESIGN DIMENSIONLESS ,R'EGIONAL FREQUENCY CURVE ANNUAL INSTANTANEOUS FLOOD PEAKS FIGURE E.2.9 \ \ ( II . ,I I I ( \ ( I ,) '. j I I 1 i 180 165 150 135 120 (/) ~ u 105 0 ~ ~90 lJJ <.ll ct: ~75:x:u (/) 0 60 45 30 15 0 1.005 .2 5 10 20 50 100 1,000 K),OOO RETURN PERIOD (YEARS) WATANA NATURAL FLOOD FREQUENCY CURVE FIGURE E.2.10 l \ l I -I I -I ! ) \ l 180 165 150 135 120-(/)u... <.>105 0 0 Q-90 ILl (,!) a::<75J:<.> (/) 0 60 45 30 15 0 1.0052 5 10 20 50 100 ~OOO 10,000 RETURN PERIOD (YEARS) DEVIL CANYON NATURAL FLOOD FREQUENCY CURVE FIGURE E.2.11 .,. .~ ,I ./~I ..... I /~ 1';"'- I ~ ,. f' I .. • I I , :;,'" I I f\.; I I ! • I I: 1-+--r-:....~r +-t--f-iH -H -++-+.+1-t-+. I ':.... 1'-' J i I I H--'-+-f-H-t-f--H-+t++-t-+-t-++-t--j-I-t--+-+-t--Jr +-+++-+-+\1 0 8120 >< (f) u.. <..) w 80 ~I ' G: <l::c <..) en-... '0 40 ..-r ! J. f l j, ( \ I I , i ( ( TIME -DAYS SUSITNA RIVER AT GOLD CREEK 100,500,10000 yr.FLOOD VOLUMES 1 LEGEND Flood Volume ft 3 Peak Discharge (cfs) J ,I -----100 yr --500yr ---IO,OOOy 122.3 X 10 9 178.2 X 10 9 310.0 X 10 9 104,550 131,870 19a,000 \ L FLOOD KYDROGRAPHS MAY-JULY FIGURE E.2.12 I-++-+-.-t-+-~-+,-l-,il-~-Hi-f-+-t+l-+++-+-rl--H-+t-t+1-+'rl---hl-+++~H--,--t-+-H-+-t-+t-+-HH-H--j ++--+-;--+--1f-l-f-hl-·-tt:t=i=;jjjj~itttt:ttijjtlj:~tt+-.f-+-h+-'--l-+-;,_-+~~H-!,-:I-h~f.-j-tH-i-++-;-H-t--1 I .!I---I--+++-Hf-f--H--t-;.+-H-H J I I \, J , I++~--'+++-l-I-+-"-+--+-l--+-l+160 200 -j H--+-,'-+-,+,-t-!-'-i-t-+--ir--;-+-t-l-H-+-+--+-f-+-H-HH-H-I-+-t-+-H\--f--i--+-I-l----+,l-+t-+""!i++-+-t-I,-+-.J....j.+-I-H ~-+-t-'---:--H-+-I-i--H.....--+...;-t-+--H--H-+++-:i-l--I--+-I-l -+-i-l--1-'''.li-;-1-~-I-I'~I :-I'"+'-+'-\-i-+-H-l--I-!--1-'I.y --;---+-,I I -;- H-t---+..+-t-+-i-,+-,+t-;-i-+-H-l-+-+-H-+-+-+-t-H-~-I-~-H-'IM--H--+-j.-,-i-i-,-Hh-+-;.-l--t-r .'t-+-'-t-++-t-i --,.- I I ! .I I I 40 j;..f-~i i ,...-.r'" I ,I :",;..' ~ I I I , ( 0 -15 -10 1-"'"I I ,,,i I , ..J ,.~ \.r."J , _--.:::r ;,...... I ,I '~, I I I,I ~~ i..A'I ,1'.''"~:'ooi i'Oo. j'A''"'l"" ,I ,l.-I !"-",! -,.;:I ,'l--'-, ,!,.....,,-II <I -!! 15 , I 10 ,,I , 5PEAK TIME-DAYS -5 ,. J I I I I , I'I ,...... §120 x (J)u- U I W C!) n:: <t 80:c U (J)a SUSITNA RIVER AT GOLD CREEK LEGEND Flood Volu me ft 3 Peak Discharge ( c fs ) ----100 yr --500 yr ---10,000 yr 53.8 X 10 9 78.8 X 10 9 140.0 X 10 9 90,140 119,430 185,000 I L.. FLOOD HYDROGRAPHS AUG -OCT FIGURE E.2.13 \ "';··· ..I r.:.er"':11 ''''''~"~~..&lIliol (~U.l.L':"(':~(.:u M: ,,.,I-l.---__ MAV ?C ~:c.c "K JO tc ~0''''-':,..s,.t .....IIGI (Qu tt ~h'::U:-H aCTa .. "j_.~"·-,---> (-,., :J I (~ -<,:·.,·:, ..,.-'--'----------~------~ -'-__'~1 __ -------------,...---- FIGURE E.2 .14 lI.Q.ll.i I FLOW DuRATION CURVES IAS[t ON 1IiI£,lil r-l.H.'Y FLOWS 2.PERIOD OF 'RECORD:.'I'50 -.,II I i" I Ii ) MONTHLY AND ANNUAL FLOW DURATION CURVES SUSITNA RIVER AT GOLD CREEK SUSITNA RIVER NEAR CANTWELL SUSITNA RIVER NEAR DENALI i 1'-• ~'-!----,-,--"'--'O--"'--"'--"'~-K-.., 'll"O''....1 D'SC"'11t61 (Q\,I.l.LLE~_,,",r_CH=<: ________i ~__.l_ A ....IL 2'l:5C'.0 !lC foe 'e «:; %0',._[D,S,C"'f1G([OU.l.lL(:::;.o.t':HX: 1 -.--.- ",'•., ,:~~:~~~_.__~--~-~:=r~._-"j~-·-~?'b ----- !4 :=_-~"~,=-~~--:'-'-':'_:l--:"=-:-:--_;~.-.: ~:J~--:------'--.----.-,- .-..---._---..--- ~-'_._-_.-.-:---,-~----;---'._~....,.....- ,0'·•,· .it'..,, 1_"K .,~(,C '..K1 %O',••[OISCotlltGE 1000.l.lll:::>..rWClEOlr AUmU.T '0',· ~'+-----~----~-------"' "I MA"CH .0 +-+-'-,-,-~"'--.:...o--"'--....---'"--"':...,-..:>..~ "i"O'tUol[OI!oCtlARG((Q"'~LL[O QAo [)'((lO(O ",''··,·, "';··•, : u , ;, ,. --,,·---'--I,-,-~-!-,I ';DENALI;-!··~!~~F~~--T:-i "'·+-c-~-r--i--.---r-~--i---T--'> ~~~~~~~~~ "'"0''.1 DriC_U(19\1Al.L(D 011 r-CltOlD ANNUAL ,'""I f(lSOeo~ClI'O" ....,,..1MtC.u.1 Ieu.aU.lO _U«I.O ••c ....... .~------ -----~._-"-.- .. =:-:-;~:-~~~~::=-::-~;~:f:::-:--:;--...--'--,'---..t-0 ------1--.--t ~ --------------"""'-----------------'o~··, •, 00'::::1 ,'j; :-:-_:===-.c DENALI ,,' 2 I=~~-'-:_-_-,-,-.:.--,-'-._-__=-__-_-,-.-----.--.--.-- ~.-1f------'---~~-----'~'--"OfC,lc::O"(I~«1lO~ .,.or HUt D.SC._.~l EO\lllLlO 0-[.U[Ol~ "ULV t"-',. 'O·+---><---"'''---'-O-~",-~",--",--'..,r--'''90"''''--' %O'T'Ut:OIStH-Ul,([OlioilLUl a-t:.CUtJ[{\ 10:t :--:-"---"':"r-:":"':~"':":---':_'-'~'-~-~---- ,·,'-_~--:u:t=-_,i~~::L __--- ,~=1-I ' l~-:'!-1 ",;:~~.~:r~.~:g:'~:~~-~'~:_~-~~~'~S~--E;'~:j::----t ,--+-- ::~~t~::~=j~"t ~:--~:'J~~L~:-- ~~t~i_CI·~~'NIT~WI,IEI.~~L~,;,,~~~OE~-:-~N~'~~_L!I,~:i,I~~:,..Li·~I·-.-,.~+t·•.~._' ~-,,-~"_~~;~:-';;:~~~~f;l .-.- _..l=~~_"" "ANUA ..V ",'·-----,-·· "'·+-~-",';--..r--i'"-"'",--oo;--',;,_-r",--",-'---; ...01"1'_[OISCHARli['t:QUAlL[O OIl:("C((O([Io ~~~~~~~ ...or 'I.'Ot~-...[tOU'&lL[O CIA [.,uO£C' ",UN. ftI.otO.CI'OMl...,,_~I~'_t.c.u:onROV."'" ",'•··· ~' ~_J.~.-c~"'-'.;,c~'~-~.:=""_"'.---~=_~..---.:....;::.:...:.:-:----.:-·__:,L--; .r~,.--_.~...,..-~---'.-":'--'i l -~ ~,+-~;::::-...~~o....,..-t.,..-'7' ;; .'r-," ',j'..,_,,=:':':';"'__'~'.-'.0',·,L-:=e~:$-:-C-~'"-~:~:~11'~i':--=-::::Il-'-:-:';~:~~,;~'.-~-~-l:':-:-I:::~:~-;':';-I:~;~£~-:;:::.~::-~~. ,~--t..,-c-f-....~-- -1-.-;-.~+:-~::'_~...'i'~-':::'='-~~~.~'~i ~.~;,~=~-+ -j M"'V '0'J'__ -:-;--------:--=l..---..L.-:: ---.-._-----;.-,-.--_..----------. -l---I .i --.:--r .-::p:-,- "'.-er,--..----;;.--...;.,--..r.-..;;.-.,-...,-.----'-..i-I--;.,------;..;0-- ....Of '11K OltoCtldiu:I~"~L-io ,,'[sellIlCO e:., :_~_l-1__~L__ 1 ..... 00)I\------.-.~I--._:-._:._..~__~__~~__ !~~~~~~~'~-~'~i~~~ .""--' L ..-..-~I"i·.--:- .'-1 i e'+--,---;--,-'-ooT--.--;--,--i---,--,-- m "~*~~~w ...Of"T.r I)IIC .......&(IIIUoAI..LlD 0l'I [ltlUIlO .CTO.... MONTHLY AND ANNUAL FLOW DURATION CURVES MACLAREN RIVER AT PAXSON to JO-oto-o rolO ,.OJ",'r*t Ollt"loIII"10000"LL£O 01.UCUDCD........" "'f'';'':.~-.-..- FIGURE E.2.15 e,:.'r~'IIIII-~·""]'<~j~"~lf·ti -. --:~:::-";;..::"':,-i.-;_-~'_~-:--,-~---: --r--r-:----.•-;~- -~--t-~.t --r---t-. •...."'Tc.,'~,;.-;,.:t_c..'..-.-1:=e,.:..;;_~;H:.;""C '::':=;'"'=,7-;',.,:.-:"';i~;':';,';,,:c~#.:-f;:~-:~':.;,.'F"1-, "'+--,---T"--I0.---..i---;"-~..--..T'-'J,,'--""';'--...'"-- %Of"'<II[(»SC ....III[IOVaLL[p oa Ut([OlCO ; ....T.M.... 10 lOiIO WO.,flO .."'0',..DdC-"":I UO ..uc.u.u .........U L. ;1 !-::.i f--.....--j, -~~I '=c- ClIO 10-0 to eo 1'0 eo ..0'"'-'::Ot&c.__n [ou.....L.ro CJll [.ClUto , e~~~~'!L~_~~'~'~~~~,.~.~'~:'E'~'~:_~~~'~I~~~~~ e'+:.:-..;·..;·f."-·'.;.I_~::....::..'.;.:-:..:_'_.:~I,_.'_:'_';""":_':_':-..;"r.,.·-:.,---.;-t------,:,------;-- , j , 10 1 r---;·";~..--';'--..+'--..r,--;,,---~..--.,;-,---'';'-- ...Ol'T-e:DISCo&AIISf.1-.uA4LCO ()II [-.eUO[D ...U.U.T .' •••.olDlOeIl ...-",.-:tltKJtMtM _.."UU_.. ""+.:.-,....:-.;---'-':..-r-+-'-'.;.:..-.;r_-,.-'-+--r----,,-- ~M _~c .~c * ...Of ,Nit CMacM&llH 19U&LU:O 0-lIeullC• ......U .....V .,'+'-'--,--+--'T----,f-'--.--4--.--+--.:---.-- 10 110 -a to ..JIO • ...or ,.-.DtK~IWM.UO 01 ucn.•o .lUL.V ..'+--,--+--,-~i--i---+--r--j---r--i-- DO·.,to eIll'O. ..fI T-'OIIIC lWA&.L[O OIl ueu.o_. -._._-'-~.--~ "....~. ...0#'...K......c IW&LLlO 011 UC.... ·i_IIII·:~"~ , • !• i I ~';IIIBIII.',,•, • ...--~~...........- ....,••-................I-ec....._'lI.M_.. FIGURE E.2.16 20 ~10 ~~ro ~ ""0'1I1f[O'S["IIIG((QUIl,.L(O (lII ['[((01[( acTa.... ..--.-_.._-._......,.,..-.,..------_. I '..-.._..-.::.J~~_~-~_ lOt .,• t ---------.------..·-~_.__._.._..- ,--------=!'=-~-~·· .---_.-----=--._-~-_._.-:_._i.__··r-'- .._;..'-1---~ ---~_._~_._-_:...._----;---------:--'-~~-- MAV i --- .._._-~._--.:_---=----,..-----.-'-----'--- _.-~_._-- ---'-.-----'------------'--<--_....__.. 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I FLO'-DU"I.TID""(.I,JJlvES 81.5£0 ON MEAN iOAllY FLO,,"S 2 PERIOD OF flECOIIO:.Y7!J;-W'11 to;-------~~---,-------------".-!--r- ~.---.-----'T'_::- :----~~;;f~~.:-:~:;~J--:;rl=~ !•\:.-• ~~-;-~·'-----F-'--"7-----~L- 00';-=-~~-==.:..=.=..------_.~.~=~...~..-:~_..: ___nO·-i---.I--·- ..'··,·· ~r --------.:..~ ,•.j:.....-.~--.---:-----n !)2''-'Jr'""~.f;(IC 10 :Y/ ,,"0''..cnc....'l [OU,l~L£C a-"CHDH ••"T.M .... i'----:----:-------:--:-:------' .. -.------.-.-------_..-------:=====-~~=:_-~.=-~ . •:,'t ~~)-;-~-;:~~:~~~T:Co. .--==-=--=.t==-;-~-----!-~- .---;----.-----+----------_._L ~_'i --~--.._.._-... -:~~ES~~=--__:~T::==~--.i::::-::C:-:_ -,-~--j~-~-_-r ~--C- -~-_._:.......-_~-_._--~_._-_._----- .....J-.-'., !-~::::=·f-~:=:~-=-.,.~-- .---------._--:-_.:,..,------'- !- ",'····· i ,,---'---l---------------- K'...{o ,"A..:J'.....(!.!,s(...II1lGI (O\ol~...l:'0"(.~f(O([ ",'.. 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';-:_.- -;- .._-.--._-.___,,_.-0-.'_4 _""':.-• ·---..~1-:O-~ "'~·, • ~. !• :.j..:::. .-T--. :1..L_. +~+.·r.....-;---- ",'\~::.._•.1 ..;~;t~~-~ .~--~~---- .".--.-'-.-..-.--.~~------T_.---.-..-,]~-~;-.....::.:.:~--~--------~~·=tr~=',F-=-- :~f2t2~:-lri-~ -~.:.~"t:----:..'-I---.--.,---~~....,..---,--- 20 ~40 Wl t(I ro ~!,c;)JOO ,.01",.(OtSCIUAU 10001lL[O 0Ii ('e[(on, ••~T.M••" -_._...-.------_.. .::-~':'__:_.+~-~2--_~~~- i;,;,;,,-i .-L_ ;.-----------._-_._---_._'_._- , f---~r I ",'. ~+==:t.=_~:=_=_::::_==.=""~:=_=_==.~:=_=.=_-=_-=::.'.;::;_==_:_=-.;-- '-·--f~-~'~-=~=~--=-~--·i-----, ! .)--~-- '0:.,-r'""';:J--~"'___:------~-~==-:--I-·--~---~~·~·±~··.~--'T~-- ----i-:-:=.:~~~_-:J-·~·==-r· ~~---.-~----.---,----:--_._'-- MA"CH (l10JO"O~&O'01lO tOO ~0'"ltI[OlSC"....G[EO.U"LLEO :)~[_C[[DEC -:----;----;_._-_.:.-_-_.-.--.;- ..:--------:----:-~_..--:-:.:-:-:-.-.-_._...._.--... .o~ ::-:.-:--=1~=.=:.:-:-;::~:-~=:--==-=-::=--~__~=-=:'--=--.:i.::::::·· , <:t '~~~<~ "';..~-----=-.__:~-~-~-=::_~=~~~~\:-~~-.~·· ,r,";~-~-,-,--)()--.-'~'-cl-.-~"'---"'--oc--..-~":O "0'''''''[OlSC".....G[[OuAU.[D ;):r {.CHD!t AueU.T ~. 1 :::--:--~._~.-~-!~_. 1 _._ ...+---.-.--"'r--..-~"'--..~-..~---i..-.....,."'-...,. ...Of 'U1E OISC......!il l.0UIolLEO QtI [1([[0(0 ~',··1 ------------,--_.-.·.- j •I ~~&0 ~W ~~.~~ ~o-ntl[Ol!oC"ARi(f:OUALl[C ()Ii;(1l([(DU .JULY ",'·•,··~. -I,·, ,_._-_._-----_.'-'--~-+--' "'+--"--'-.~-I0""""-'-O--"'--..~-..~--,..-.....,...--ooo.,......- %Of '1IIlII:OISCtdlllill [OU"'~L[O C*[1,([0(0 .JUN. i._.._--------:-:-"----'-~.:---~--:--"- ,·'+~~--"'--I0..---.:-.-,.;"'--oo~-..~---i"'-.....,...--.., %0'"101(OISC .....GE EQUAI..LlO O'l'EI(E[[II:O ~i '==~~=f=~~l;:~a~G !If-.~.-!--~ ",'----J-------:__~j ---_1~--!----F~--·I--,--f----= ~._--"----f --~:-_!----.:._...:-.1_-.---.L __.__1'=:::-:-t=-=--::~--=---1_1.-~- I --~~}----~-.-.-.~--.--;-...:.._ I·l!t.....~---:-'.C'_cci -·-'--:---1:.~ ro~.,-=i ,_~-.~_,_~_., •::~-:~~I~-~~;:f=~~~f~~·~Z ~==-T:: ,,_._~--'----'-:- ",'··, •• f1 [\) fl I [;.I lr J ) ',', I .1!Qlli. I fLOW DURATION CURVES BASEO _ON hlE~"fAILY FLOWS 2 PERIOD .of "[CORO'CHULITNA ~IVER-WY~9-WY72~W'f11 TALKEETNA,'UVER W'165-WVfll FIGURE E,2.17 " !,l I MOiNTHLY w AND ANNUAL FLOW DURATION CURVE S TALKEETN~RIVER NEAR TALKEETNA Ii .:: -_.-;-.---.-:-------~.--':".--,'- 10 lOiWl30lO7D 10 ,.0'1 n.{D1KtU.'![OU'&lLEO ()Il E_CHO(Q ANNUAL .',.C_j ----~---__1_--'--r-~~-~-----'-:----- --~--.-,-----~-----.----.-- 10't L ,'.______:.__......:-._~.__--..:....____,_ ---:-::::=~:::~.:.=::::t==:.-:=:-:-:~~:-=-- _.-_.._._-.-:.----!-----.--~--"---- ..'+::.::..:-r---'+-'-'=;.:.:.-C..1--'--T'--~-...;...-'-.;_-..---;_ ~~~~~~~~ ..Of',..~.[IOUA~LI0 011 £1(((0(0 fie...... ..'+-..-..;.....,:-'-'+..:....-+---'-T---':-'--i---'+--r--t--~ to 10 1040'!I£lIOf9. ...til ,....-c....-:•...u.n 011 I_CUDlE! Nav••"" I'IIiIl·--i_:..'..-, .1' .....-~i I ( Jl f'l .I I ~rl l, :1/...I l ,\ I 50201025 RECURRENCE INTERVAL -YEARS 1.1 1,000 L...---'-..L-..L-_---.L --=-.... 20,000 Ii \ I 1 i 10,000!9,000 8,000 7,000 enu.6,000<..> I ~5,0000 ...J U. ::E 4,000::J ::E z ::E 3,000 rI \2,000 I j I \ I,' I I ,I SUSITNA RIVER AT GOLD CREEK LOW-FLOW FREQUENCY CURVES MAY FIGURE E.2.18 50201025 RECURRENCE INTERVAL-YEARS 50,000 40,000 30,000 (J) I.L. 0 20,000I ~ 9 I.L. :E ::l :E ~ :E 10,000 9,000 8,000 7POO 6,000 5POO --=-- 1.1 ,\ I J I I' I', \ -I SUSITNA RIVER AT GOLD CREEK LOW-FLOW FREQUENCY CU RVES JUNE 1 {FIGURE E.2.19 !\ I -10,000 rn l.I. U I ~40,000 ~ l.I. ..... 20,000 10,000 9POO 8,000 7,000 6,000 I ) ! .i 5,000 L.-.....J.-.L.--.L__-'-_-l._~ 1.1 2 5 RECURRENCE INTERVAL-YEARS 10 20 50 SUSITNA RIVER AT GOLD-CREEK LOW-FLOW FREQUENCY CURVES JULY AND AUGUST I I i L FIGURE E.2.20 20,000 SEPTEMBER ISPOO I I • 10,000 9,000 8,000 I I rpeo \Spoo SpeO en 4,000 L<. 0 I ~ ...J U. ~ ::)r,ooo ~z S,OOO:i OCTOBER S,oOO ) 4POO -=--I If )3,000 . }, I 14-QAY 2,000 1,000 1.1 2 S RECURRENCE INTERVAL -YEARS 10 20 so I ,/ SUS ITNA RIVER AT GOLD CREEK LOW-FLOW FREQUENCY CURVES SEPTEMBER AND OCTOBER ) I L FIGURE E .2.2\ \ ( ! 502010521.1 5,000 '---.L.--l---L__-I-_--'-_~ 100,000 ,...----""T --,---""T__-.-_---r-_----, en 50,000u. () 0 40,000 LLJ 0 LLJ LLJ () 30,000x LLJ c:: 0 0 LLJ ...J 20,000...J <r=>0 LLJ ;t 15,000 0 ...J U. 10,000 9,000 I I I I I ) i') ,\ I \ 1,1 RECURRENCE INTERVAL-YEARS NOTE:PERIOD OF RECORD IS 1950-1981. \ ,) SUSITNA RIVER AT GOLD CREEK HIGH-FLOW FREQUENCY CURVES MAY I I L FIGURE E .2.22 50201025 RECURRENCE INTERVAL-YEARS 1.1 10,000 &-..--1.-.1...--1.__-1-_--1.._----1 i i ,I) , \ \ 100,000 i 4 .r enIIL. (,) I l 0 50,000UJ 0 !UJ UJ (,)40,000x UJ a: 0 0 30,000 UJ (I ..J ..J <t :::la UJ 20,000 ~ 0..J IL. 15,000 SUSITNA RIVER AT GOLD CREEK HIGH-FLOW FREQUENCY CURVES JUNE FIGURE E.2.23 70 60 50 \ 40 ,.30 II 20 JULY en l£.. (J 0 10 0 0 w (!) a::c:r 100 J:90(J (J) is 80 70 60 50 40 I (30 [. 20 10 1.02 1.05 2 5 RECURENCE INTERVAL -YEARS 20 50 SUSITNA RIVER AT GOLD CREEK HIGH-FLOW FREQUENCY CURVES JULY AND AUGUST FIGURE E.2.24 SEPTEMBER 40 20 30 ,I I l 10 9 I 8: 7 en 6 lL.. U 0 5-0 Q 1.02 1.25 2 5 20 50 w RECURRENCE INTERVAL (YEARS) (!)a::: <l: :I: Uen Cl 20 (,OCTOBER \(10, 9 a 7 6 5 4 3 1.03 1.1 2 5 10 20 25 50 RECURRENCE INTERVAL (YEARS) I ( SUSITNA RIVER AT GOLD CREEK HIGH-FLOW FREQUENCY CURVES SEPlfEMBER AND OCTOBER FIGURE E.2.25 r---'--~ LEGEND: ___DAILY AVERAGE VEE CANYON -...-DAILY AVERAGE DENALI •DAILY AVERAGE SUSITNA STATION (SELECTED DATES) SUSITNA RIVER WATER TEMPERATURE SUMMER 1980 OCT.SEP.AUGUSTJULY .~ .~,,~ 'I X \ I ,1\ L {\II:,r\I" ,,\~I,'\~I I I \.'\~~1\I.t\"~",:II I.",I I ~... "'P'I"'I ",I:,"v.~J ';",•\:I,I 1\;\'I~""":"1~.~'I \I \ •,I,1 ,I~f,r ,'I " I "I I "I ,i ¥,,I ',II I 1 ,,I I f ~" I r 'w u',';II ' ,II ~JII 'I,..J , 'i ~ JUNE t t I ·:1\I , I ~ I I I /I I dqll 141 III /I1~~I I f I 1/I 11 I 1 I~,I , I I ~~ "~ 14 13 12 II 10 9 0 0-8 w 1\•,\ 0:t :::J 7 ~I I <{, 0:6 I w ,Ia. ::E 5 I W I, t-I 4 4 I 3f '.1fllr,t \1 2+I ¥} I,, J 01 I MAY FIGURE E .2.26 r-- I'! C\J I lJJ :J w <! 0:z <! w a:: 0::::>~Z :::> ~-W ~ lJJ <l:0~ u.. >0:(X)I- -lJJ ~~<! 0:0...w <X ::::E 0:w (!) (!)<!zlJJlJJ <!a::..-..-~a::w-~w ~(1)0::::>~ :::>lJJ(1)~~ (1)..-- ..J :::;).., ) I L o CD SUSITNA RIVER AT WAThNA WEEKLV AVERAGE WATER TEIVIPERATURE 19B1.WATER.YEAR' 12 10 8 6 u. ll.4 ::!: w I- 2 o .----J LEGEND: @ WEEKLY AVERAGE TEMPERATURE II ENVELOPE OF WEEKLYL.:...J MAXIMA AND MINIMA -2 I I I I I I I I I I I I I I OCT. 4 NOV. 8 12 DEC. 16 JAN. 20 FEB. 24 WEE K MAR. 28 APR. 32 MAY 36 JUN 40 JULY 44 AUG. 48 SEP. 52 FIGURE E.2.28 15 r--r--------,.------,----"'T""'1 15,.....--,--------,.------,.---.,.., () o I a: ::Ew ~ .::-------------..... ::---------()o Ia: ::Ew ~ -------------------------~ IS () o Ia: ::Ew ~ OL-...".l,,""""'="::---=-:-:-__.....,.~ 26 137 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-6/15/S0 O.....-='=-:-:~---___::-!:-::---=:~ 26 137 224 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)·7/IS/SO -------- --------------------~ "'- IS O'---='=--:-::~---""""='~--_=:=_=_' 26 137 224 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-7/I/SO oL.-*------d=:-----:::~--_;:;_;:b'26 137 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-6/I/SO ()o I 0: ::Ew ~ ( l IS ,..--'T'"------......----.,.....--......,~ ~-~- OL-...,..,.,....,,~---......,~~-""""='~ 26 137 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-S/IS/SO ISr--...------,.....-----r----.,.., () o I ll: ::Ew ~ :;---------------------~-----~'-------.."---,.............. '-', "".... OL.-*=:--__--=±-:-__"":'".!::~ 26 137 224 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-S/I/SO () o Ia: ::Ew ~ O......-::!'=---:*--:::-:!:-:'__~ 26 137 224 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-9/IS/SO 15,..---,-------,.....-----r----.,.., () o I ll: ::Ew ~ 15 () 0 l Ia: ::Ew ~ 0 26 137 SUSITNA GOLD CK.VEE CYN. LOCATION (RIVER MILE)-9/I/SO LEGEND ----MAXIMUM ----MEAN -------MINIMUM NOTES I.)ALL TEMPERATURES WERE RECORDED BY THE USGS WITH SINGLE THERMOGRAPHS AT EACH SITE. 2.)GOLD CREEK'S TEMPERATURES MAY BE INFLUENCED BY TRIBUTARY INFLOW AT THE SITE. 3.)DAILY MEAN TEMPERATURES COMPUTED AS AVERAGE OF MINIMUM AND MAXIMUM FOR THE DAY. i I I l' SUSITNA RIVER -WATER TEMPERATURE GRADIENT FIGURE E.2.29 ._--'..-1 '....~ A 15 10 5 o PARAMETER:TEMPERATURE.°c -l-HH-I-H-#-H-f-HH-I-+-I-#+t-f-HH-I-+-I--++++H-1H-1-H-++++-l-HH-f+t++-H-l-Hf-+.4++-l+-H-l-H4-t-+++1 --l-Hf"'H,++++++f-HH-t+t+I-++-j-HH-t++++-H-l-HH-t+t++-++I-H++++++-++H-1-+++++-+-~I-l-t~ . . --~~tF-~-~a _~iS -:~I_--_'f t :~ •MAXIMUM MEAN •MINIMUM '""OBSERVATION SUMMER :WINTER BREAKUP' D-DENALI V-VEE CANYON,a-aOLD CREEK C-CHULITNA T-TALK~ETNA S,-SUNSHINE:SS-SUSITNA STATION A.Shall not exceed 20°C at any time.The following maximum temperatur~shall not be exceeded where applicable:migration routes and rearing areas--150C,spawning areas and egg and fry incubation--13 0 C (ADEC,1979) Established to protect sensitive important fish species,and for the successful migration, spawning,egg-incubation,fry-rearing,and other reproductive functions of important species. DATA SUMMARY -TEMPERATURE FIGURE E.2.30 /'Devil Canyon:7 River Miles 'Q V RM =River Mile Ryan Surface 0 Ryan Intergravel •I YSt Surface YSI Intergravel .....(Slough 19 0 1:1 ~Slough 20 ..., -(Slough 21 '" .0 ,"0 £I RM ~ OBI OF.! Sherman Creek , \Talkeetna:26 River Miles RM Indian River /Direction of Slough Flow Direction of Flow Fourth ot July Creek ;. I .\ i ,\ L Location map for 1982 midwinter temperature study sites. FIGURE E.2.31 Datapod Surface 0 Datapod Intcrqravel tn : '----_.~,--_.-' (SLOUGH 21 SUSITNA RIVER ABOVE PORT AGE CREEK (RM 142)(RM 149) \ 111.11 31-SEP l:S.1I "AUG 6 '"AUG 31-SEP 6 u a.a U 12.a \v v S.II 11.11 a..7.a 0-la.1I:t:1: W S.II W lJ.Bl-I- S.II 8.11 I I I I I I I I I I I I I I I I I I ....lJII 198a I SIIlJ ZZlIa liHlJII '98a Ieee zzaa 11.11 SEP 7-13 IZ.B 7-13SEP '"'.11 1"\II.BUUvv 7.B IB.B 0-15.11 a..g.B :t:1: W S.II W S.Bl-I- 04.11 7.9 I I 1 J J I I I...."'"IlOlaa Ia lOla 22alI Go4QQ1 IQQlII ISQQI 2Z:BQ 9."SEP 14-20 'I."SEP 14-20 1"'\8.B -='"lB.BUU v 7." v 9.B 0-e."a..s." :t:1: W S.B W 7.B l-I- 04.III e.a I I I I I I I I 1104"'" t_ laQQl 2Zl111 a-4QQ1 looB 18l3ll1 2299 ,('S.B S.B 21-27SEP21-27 SEP '"7.9 '"7.9UU V v S.B S.B 0-S.9 0-S.B L:L: W 04.B W 1.9 I-~ 3.B 3.B J I I I i I I I 9"'lJII I_a I e0lJ ZZ:BQ lH_'90"I elJll ZZlI9 TIME TIME FIGURE E.2.32 Comparison of \,/eek]y die]surface wa ter tempe ra tu re variations in Slough 21 and the \ mainstem Susitna n·at Portage Creek (adapted"lver -from ADF&G 1981 ). ___I INDIAN RIVER DAILY AVERAGE TEMPERATURE (BASED ON PRELIMINARY DATA FROM ADF a G) ----PORTAGE CREEK DAILY AVERAGE TEMPERATURE (BASED ON PRELIMINARY DATA FROM ADF a G ) SUSITNA RIVER DAILY AVERAGE TEMPERATURE (BASED ON PRELIMINARY DATA) ,.... \.., /'\v;VJ\ .Ly':\\\..,~.f ',.\v!........../ !"'---",'-\,";"'-V.~; "'\1'" f, 01 \I' \\j "i '.t\"\J'l'._,'I '1 ~,.V'••"~I I VI "J 1 \1 , "I ' ,'.....",)'"f 15 14 13 12 II 10 9 ~8 wa:: ~7 <l:a::w ~6 w I- 5 4 3 2 301020 SEPTEMBER 31 AUGUST 10 2031 JULY 10 20301020 JUNE o I I I I I I I I t I I I , I SUSITNA RIVER,PORTAGE CREEK AND INDIAN RIVER WATER TEMPERATURES SUMMER 1982 FIGURE B.2.33 ---. i PARAMETER I TOTAL SUSPENDEILSOLIDS,(mg./1.) H+I-l-H+I-H+'--'-'-...·_·-·_·...·-·-·-H-++l-H-·I-H+I-H- . •.••.•.I _1_._'~.._•M.'•.•_1_t-.J--I--+-l-~-I-+-1.-1··1 -...-..-..-..-..-._._.-.-.-•.+..++-H 6000 I I I I I t·-··-~···..·-·-··-..·..·- -.~-.-_.-·~-·-H-+-+-l-+++++-+-l--I-H-H...--I-I-H-I-l-I-t-H-I ++t -f ·H++f-H-H++-I-l-I-+-I-H...I._-.-._....l-+++-t- -_._·.··.-·.-_.-.··.·.-.·-.......+-...-t ....-..·.·,··~·-I-H-H-+-+-f+f-I+H+H- ..•_.•.•.•._.-•.•-......-•...~f-I--H-t-.......--.....-.-..__._-._._•..~.-_.-~..-.-...I-++H-I-H-I-t-I-4-I--+-I-H-H-H...+-H-H-I-I...I-I-I-I-+~-+··H--l---H--I 4000 I-++++I-·I-H-I-l-I-I-I-+-l-I-I...H-I-I-+-H+I--·.·-.·..--.· •MAXIMUM ...•.•.•-.......•··..·1-1-+-·14 -MEAN ~OOO ..-.---- -..-.-·.-·,-·,·-I+I +I-l-H+++I-+-I-I... ··~I ..I]]±ITt[I~.tttttttj"1:tj·~.l="tl+i~+l4=ttttttl.l:1J:nl~n::rl=fTI=lTr:r+ttTL. -I-H+I++-+-I-++I-I-I--I----- ;-I-H-H ",----"..1-1--1 I 1 I I j-·H-I-l I I I I 1- •.MINIMUM _1._-1.1._"_.1 _-+_1,_1 _.._a_.._1-1--"_"__"_"-.-1-·1-1 -1-.·-I ..1-·-.I-_.1 _ 1 __'••·••··1-•-1·-1--1-1-1.-&-10-"- o ...._.·1_1.'_I ··1 • I .••-1-'....-.-1--1 -t··I ~I ··I--t·-I _·to ....-....-·1··1 -I·-I ·1·1-·I-I-,·-t--I-t·-I··1.·J=.·-..........-•. 1-+-f--I--I-+.~j_,I~-1_I_.L-J-.l_I_I_.l-I_.J.l-J __l ...1-1_.1._1_I ..I.~I _ I ......1 _1 I _.1 I.I .1 ._J .I _.I.I .•1--1_1_.141_1-.-.··...-.~..- .,.._.___"-'-"-'-1_-1 •.•..•__.._'_1_1.1...•-.-.1-1--..-.---- --.--1----.---- 41=08SERVATION 0-DENALI V-VEE CANYON.a~aOLD CREEK c-CHULITUA T-TALKEETNA S.-SUNSHINe SS-SUSITNA STATlOU No measurable increase above natural conditions (ADEC.1979). Etildblished to prevent deleterious effects on aquatic ani.mal and·plant life,their reproduction.'. <.llld habitat. , DATA SUMMARY -TOTAL SUSPENDED SEDIMENTS FIGURE E.2.34 1-- en u W <9 0:: <t :r:u (/) o 5..t=t:- 4 :. ,..jlUl:t:n.ln= ._- fHI~n :~==--,.I::::t:._=:=..,:~.,Trr,I~...-,:.."'1'-O>"'1:rii ~~'I.I '~l)l ~ 1~:.',•.!t ".l ..~l:t: -"'"i~J :f.I ttl : ..'_ _ _,..:.:..I •.'.m 'I Ii --'''.••l;;.<~·1 1 It Ill'li 1'1il:'1=:'-.-.-i:l fl:;:;;:·ml.•.•be It:\'[ffi·l 1 ·tl11~'-mI'_.Q.fl:1 ;;I:'-•.T Ii.·I~·1:II I ..I .,......- -r ".I I .",,.I ';11 I'I II I -,~",~"..::=- - . ::::::'lll:S 0J :~I:;:.::v· 2 I I, l ::I 4 I I I ! ~.6 7 n 9 SUSPENDED SEDIMENT DISCHARGE (TONS /DAY) SUSPENDED SEDIMENT RAT I N G CURVES, UPPER SUSITNA RIVER BASIN FIGURE E.2.35 ._1 1.0 I---l-... LEGEllO n.'U·,.m'l '._.'L.'".............t'In.1 .,:'". . . ::::".~::.:.:~:l::'..I·l:...~:.::~S :d7--:!'~-!.:::l:-. :;~E'::-~E~::SUSPENDED SEDII.IEliT 1110 1:::T ri'i';....LI ..•.__. _~.L!l.1.~a I'~ •.::./.....T /...'.' . : .•..I ['T..T T j';.--. .I ... ••.'::.I'"...:•.:.:::~:::::~.:-...'.j.':::I ..T-'...1.....T...J'''j ·n···~·f::::I···... r ---I-'"I '''1''...':::. i it.. "..'.....:......! -•...::......:... SIlEAIiAlYSl§';:'~,-nif-l-c·--::._~,~..STATlQII".'.,l:Y <i::::~>i('::-r~-I-~._:=,'::SUSITIIA It ......' N IIJ : •::::..__--':.;--sus I T'IA 'I GOLD CREEK'-..--:-~-'....·1::":JI" ....__I lear -...~Ui f:.:1';"~;'__SUS I HIA Nea CAtlTl~ELL I 0 II ..::1·::-t;M·,:.-r-":...-..... O lD ~I..'.MACLAREN'r DEliALI --..L.1 I ....I'. " " I .....~- .'.._ . .II ..,.....'"w:~~'..:'";'._:1,I ,'.""••_.",~~~XSOII ...!I I 7'!-..1;--.:'/.I'!;:t 10...:..:....:....•••.I .".':T'.,,·r.l··-- ..I".......'._".:.::....."I'...__.1..',_ : .'"..:'-:-:1 -f--!--j---.:.....,..I . . ..'i .'.......~~"-'-'-,.,:::j.j'::':".I .!'"cY'. .-;-.,._:_..1..2..L.j'-:J -':j "L'._."....I....I.I_:/. 9 I.I --l Z 'D ..:.:.:::::.I"I :..:..':'..:.:'.:':V·-/./:_..-..I .....':"'-~'~--l.';<""i :.'.T:::'J .1J:1 "~-'c Ld ::(~,::-!'!--:---,1.·l-~·I-I- t-.......I!'1'..,.,'L--:a::J'i ,!_1._._ 1 : • • ••••_:-.:-.• •o ...__v::;::;i0'"._,...."..I , • I i......:::::.....I : .-I~·-:.':I.:T"~;~:'.,...~~•":T':[[L'.mtt-+--,,~.....:,'---',''~:;::::::::.:"'1 .-;--+....A:J,~~':T'--:-1--:--=-_~l !!.r-1-.- iL ".,.:'__.,,~"-<'.."I ..-I......l--'--,'.".!'.._"""",=..:'.::-0'_..,,:.'I;~.I .:.::.'., %~",ci::'-~~~~,;,;,.;'.1 ;,::,.,.....'tl "","1 T·T··..~''''i'·.._c.]....,','...."'::1'",;:,.~'1'i,::'.':.j ~!,1-·-:;1":'~ttf c'~.~~-~j.=,1,1 I'e.-, 1 .1' I -l _.__..__....".::..1----;1.-.I--f-l-'-~r .i ..'r IXtlJ:_tr. j I;':::~:"'"---..._~-_._...._.~.:.I":I ;'i'::~.::~ll...~i'-'"- Z I::~:.!J..:.',i .;..:......--:-:-:-..-..:----l .j.._....,:...'..:...T':1--'-',,,.:~~i fU'"••".'.W•••••.'....:i 1 .·c:.-·~:t'~:i t +--r-'I'1+',:~::.:".':::....~.'"--..--_.:.::::::~:';;::;.:.i".~.:.,.,~-.-SOUTHCENTRAL RA RT i 0,'T -I-";'".:,............::.L"""ILBELT I 1.1 _.Ii :1 iii ifii :;'::..=.-.:;..:::.:~~::.:T 1 .I ~-~I':-'-AREA.ALASKA I'·0.00..'"••.,.. ...ALA"A ..,,!'~"_I ~:.:............CORPS OF D.STAICTI.011 'j!i'r"!"'J I -JUNEEI~~~NEEAS •. .L I I I.I ,I 11!!1:IJ: PARTICLE SIZE IN MILLIMETERS SUSPENDED SEDIMENT SIZE ANALYSIS SUSITNA RIVER FIGURE E.2.36 __I PARAMETER:TURBIDITY,NTU.,. .•.-•.-•.-..-,.•~-•..•.•-.-.-.1\.11 41 ';111-1-11=++-1--1 .......-1 ----._I_'~ 1500 .t-t-t-t-~-.--•..•-.-~.•-- ··..·-·-·-~·--1-+-J-f I II I f++-tH±[~.~~.~~~.__..._:.::gm1*t~fir~~'I I I I I I I I I I I 1-~-1-H--I--+-I-I-~·I·~--I--I--I-~·I-I-I-I-I-4-~ 1000 ..•..•.-.•....-I-I-t-l-I- •MAXIMUM -·----~-P_++I I I I I I I I I -MEAN 500 H+I I I I I II I I I I I I I I I I I II II I I I I I I I I I I I I I I I I I I I I I I I I±t±±t±tttt±tl:±ttl.tttt±ttt±l --......•..-.-··I-I-I-f----+-H·.--~..-- ..-.••-~-....-•..~-~-I-I-I--I--I-1 -•.•-.--.-.'--I-t-I-I-+++I- •MINIMUM -..-..-.-...·-1 ..H-I-+·-j--·~.•_-~-.-.+-+--I-+-+-+'+'+'---'-'-~'.-.--~~--.-.--~-.--.--.--~. ·I--I-I-+-I--I-I....H--f--I---I·~-+I-H-I--I-H-H-l...•._....·-···I-t+H-H-H --1-H-+H-H-I-+-H+++I·1-·I-~--I·I-+I-I-l---I--+_I_+_+_I__I__I__I__I_1 --l+H++-H+H-'-...~.~ ....-.-~-•.-••_---1-·I-~-...d-l-!--H-J--I---I--I-.-f- -••••••,..-I •-I _+-,·"-1-t··._.__.1-.t-.--.J.-.I.-.I-+.-I-..a.-•.••··-1-••·· o ~'H-+I I t I I H+?_:t±ttttttttt _1-+-+_1-+_1--1 hH--I-4--1-H--f-f-l-++-I-+-++J-i ..~-:1'41:12p~t'3~1-¥~12·~1151:.:t=lj-t¢£1:-1ltJl-1~j·-l!>-t1"¢rf=tttIlotttl'"11l1t-i'l-tr2-thbttdr - - J ~l-rl~1 f I:fl TIl~llf-''-L1!-J+t.1·"Jtl1::+tt.~IJ{~~~_:.:-~llEl.l1"~E[ll--lS8I-+1 -.~-1-_1._4_1-_+-4_1-.•_...._....-t-.._·.--1-1-1-4-1 -t-t--t--t-H.·'·-'....-.-1-1--1_·._1···I _.._1 ...1_..._.__6-_....-·_.._._. ..O_-A_._.···._1 ~.....·...-,..··+--J.-H+-,t.~-.-_._·.._t-+_o 1-··.·-.~.•_"._"'_--1-_. *OBSERVATION SUMMER .WINTER .BREAKUP u-oeUAlI V-VEE CANYON G~GOLD liREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE:SS-SUSITNA STATION Shall not exceed 25 NTU above natural conditions (ADEC,1979) 1::;tcJl>lislled to prevent the reduction of the compensation point for:photosynthetic activity,'which l\Iay have adverse effects on aquatic life. , DATA SUMMARY -TUREI DI TY FIGURE E.2.37 l 50 40 -:::J "'0I-~ %- :::J I- 10 2 .,. 3 4 5,6 7 8 9 100 2 SUSPENDED SEDIMENT CONCENTRATION ,, 1,1; = .. 3 4 (mg/l) 5 : i 'I o 6 ,- "I ;!'• 7 8 9 TUI=iBIDITV va SUSPENOEC CONCENTRATION SECIMENT I ) l. FIGURE E.2.38 _J PARAMETER.TOTAL DISSOLVED SOLIDS,(mg./1.) -H-f-H-H-H+H-+++-H-H+I-t-t-I I I I I I I I I I I I I I I I I I I I I I I I I I-H I I I I I I I I I I I I I I I I I I I 300 200 •MAXIMUM -MEAN 100 .,MINIMUM o -.,rrgtij!~o:=t~#l I 'F ~.G.t I .1.1 1o~1 1.1.1 I ~'""OBSERVATION."Il 3 ,I~_____:1:...~I'J..--~. 'I'...I~I 'i' SUMMER :WINTER BREAKUP 0-DENALI·V-VEE CANYON"a-acH.D CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINe SS-SUSITNA STATION A.1,500 mg/1 (ADEC,1979). Established to protect natural condition of freshwater ecosystems (SOD mg/l is the criterion for water supplies). DATA SUMMARY -TOTAL DISSOLVED SOLIDS FIGURE E.2.39 -----.J PARAMETER'CONDUCTIVITY,\1mhos/em @ 25°C -.--"-'-'-'~-"~-'-'---'-"~".-f-fI I I I H-I-I--H-4--'-'--'-~-I-I-4-~~-...-..-..-..~--.~-+~-t- ••1.,·..,-,·.,-,-,-,,-,-._~.....·~·+.·+t-H-t ++-H++-H---l-t-l--I-l--I-l-·-·---.-_.--~'--'-'-H-H-++~++++I-I+H-I-+~ 400 ,-..'---'--H I I I I 1+1 I I I I I I I I I I I I 1+1 I I I I I I I H-H I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1-1-1-+--1 -.-..-.--,.-.•.•-_•. •MAXIMUM -~---£lfJEI1I]IIiIII]IIJ'-f+H-t++-H-f.+~I I I I H-I~-++f-H _·.·~"_·I_·I ••I ,.••-t-t--t--H-,.........-...-4-..-I._'-~••I-'"01 .•1,·.1.··......_ ··-·_...-_·~--+--+++H-H I I I I I 1-\300 I--I-~-+-H-I-hot -I __f_·'·..1-1- ··--·_··--·----·-·-f·+-H-H I I I I I f- .I--f--I-+l--l-I--f--f-.-.•..-t-....-_.I-I-I-f=t=++-H-I-I·+H-H-l+++-I-H++-H+.J..-H--f-l I I I I I I I H--H -MEAN 200 -.-.-.--.....+-+t--+--t-t-+--H .1__1_·1-_1_·'_.......-.-.....,-,-,·..·.,--I+·I---H -.-•.-.-......-.-.-·--·--·-·-H-·~-+--I _._.--.-.-LLLl.J -L.Ll-t._._._~....-•MINIMUM ._-.--.----•-.~-1-1---1---4-1-1-1 100 -~--I--l--l-t--l---.--_.- __<lH.I_"_···1_+·."-1---I--I.....J.-.l--4..-I *OBSERVATION SUMMER .WINTER BREAKUP D-DI:HALI V-VEE CANYON G-GOLD CREEKC-CliULlTUA T-TALKEETNA S.-SUNStHNE:SS-SUSITNA STATION 110 cr i.ter-ion established DATA SUMMARY -CONDUCT 1V1TY FIGURE E.2.40 '_J.-~--J t A 30 PARAMETER I CHLORIDE.(mg./1.) ...._.•...-..-.-·-I-I+I-J .'•.•,····...·-I+-J-H ,1-4-1-+-+--1···...-...-....-~-.~-•••. ........•-.-.~-I-H-~-H-I-H-++~J I I I I l-I-I t-+-+~III I I I-+--J-.....~-+-+-1-1++ 20 ·~-I-I-4--l-l-I·+-H-1-+-+-4-I--I-l-l-I-l-+-.J-·-~-•..•-....- .•-.-~•.•..•..,~"-'-"-'I--l-I--+-+-I-+-I •MAXIMUM ..,.-.,-·-·I-l-H-H -·-~-~--·-f--H-+-++I--·l-H-++-++-++-I-I 1-+--t+-1-·H-1-1+-1-1-1·1·H-I--I ,H··H-H-+++ .'-~~-"""'~''''''~-I--+++-++-I ~.•-....--.'-•.•-H+-I-I-+-J-++--I-+~-++.J-H +.J--J-++-J--J.-I--I-..J-I--I-I+-I---J.-I -MEAN 10 ..~--'...~-".."·1-t-4++ .....................-•.-•.1--+:+l-4 -••-·...··-1,--1--1-1 +1..•,,~,....-- ......"-~,,,'''--I-l-H-f- --.-~-.~-.-·'~··"I-=F/--+. •MINIMUM .••---~-~"""-'-/--,-f-l-f-+,-J- -.-~.._-...~-H+H-l-H-H-I-H+H-l,-I_I·_t-_I··_I··I_I--I_"'_11.-~ o 1-+I I I I I I I .++-+++f I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I H ~'~Itr-I HI'rl''tr:11l1~~II'~Itii~1.111'r1111t.lltllttJ~glJ t~~m'11 ,.',...6 ~'8 ..25:,..,".'.'~.":::3 ".'.,";1 ..'~.23 ,-..--. -...1~1"~~9-$~.,.-r-'l:,\-:.'::.'...,..'::*:::..::..*~'?f-~~,:"..'.-~.-..:':"..'-',-~::=' ·~l=OBSERVATION SUMMER 'WINTER BREAKUP D-DeNALI V-VEE CANYON Goo GOLD GREEK C-CHULITNA T-TALI,EETNA S -SUI~SIUNc SS-SUSITNA STATION I..~ss than 200 mg/lx (ADEC.1979) Established to protect water supplies. r OAT A SUMMARY -CHLOR I DE FIGURE E.2.41 t A '-~ PARAMETER:SULFATE,(mg./1.) I-I-l--I-I-H-l-I-I-I-I-I-I-l-l +H I I I I 1+·H--+--H+H-I+++++H+H-H-H+++-1+"++H 40 I++H+I I I I I I I I I I I I I I I I I I I I I I I I !I I I I I I 11 I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I =I=J:·/=1 ~'1='1-~1-[LI :LnTT.:f~-_._.._._..__..,__l_.[_OJ=...1 ••_ .-•.•..-•.-.-.......-•...'-'-'4-"'-f-H+-r~ -.-·--··-I-I--H--+-H-++-I--H-+-H I-I-H+-+-+-H+H·+H-!I I I I I I H I I I I I •MAXIMUM ..-.-.-.-.-.-~-I-+-H--++H-H--H-H+I-H-I-H+·H++H++I-I-l-"'-l-I-t-J.-t--+--I- 2.0 _I .•_-41_·.__...·_._1_·._.·~·.-H·+H-I--I-1--'··-'_1··.....1_ ~-I-I-}-I--I-l--I-H-~...~-.--.-_.- 1-:..•. 1-+-4·++-1--·'-'-•.-•.-.-•. ..--_.-,"-_.-..-..--- +-I4+-I---4---~···-.-...~~-.- +-+4+·-1--1-+++++-1-1-1--1-1 -I-H-H ++-I-H-H-l---H--·H-++++-I-H-++-T-I -_··-·····-····-·-~-·-··-··-·-·-I-I-+-+-I~I -I.,.-I--+--'..~I--••-...-r-t-·J6 -t-rl -MEAN •MINIMUM o H+I I I I I I I I If I I I I I T I I I I I T I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I .••__••••••••1,1 •.1 __1 __••_1_1_.._,.1_. ·_o-~-·---··-1-I-H+1-1 l~,_ --._-.-..-.-.-..-...·~-·--··-·---·-·-f--H-++-·I+f -•._.••.1·-'--"-1.·1·_1 ••.•-1.·1-1·.1--+-·1 I··1.·1 __4_"'__1·1__1 -._·.,_·.·__.-·t.-I--J.-....~ :trm tj:[tillr~111T~HlHlj-rmtiHj~lnl:1tll H:ftfl~ij~gftfstFf :U::OBSERVATION SUMMER WINTEB BREAKUP 0-Ol:tlALI V-VEE CANYON G-GOLD GREEK C-CHULlTI~A T-TALKEETNA S -SUNSlUNt::SS-SUSln~A STATlOII ;\.SIl,111 not exceed 200 mg/l.(ADEC,1979). 1.::,L~Jl)1isllud to protect water supplies. OAT A SUMMARY -SULFATE FIGURE E.2.42 ------, PARAMETER I CALCIUM (Ca)DISSOLVED.(mg./1.) i- •.•_.,_1_.._••.,--..-I-I _._~.-t_.._-f -"-.f --1-,-t-j--f-f--f--t--f--H -.~..•-.--•.~-._-~.-.~.-.-.-~.-.-.-.-..-1-++l+I-J-+.-l-H-+-I _._...._....._•.-i'~.,-..-+-t-f-t-I-+-~.f-+-l--I-'-'-'-"--'-1-_.- 60 _.·.•_I_.._._..._I_I_I_..._.~..._t_"·.__I_..._·.···.·.~I_.__I_·1-1-.-..-....- •........--.-...·-.-._'··'_1_1··.-""-.'-"-f--l--",-~•.--t-",-,--t.".'f-+-I-I-.·..-t-l I I I I I I I I .110 _..,....·-1-·.-·4 -.~-f_......-l--4--+-#-f-I--1++-I+l-I-I-~-I-I-I-H-H+H+·H •MAXIMUM 20 .,..•.•-•.~·~-·-·-~~·+-·--t-I-I-t-H I I I I H-I-I-I-f-I-f--H ..•.~~..•.~-·-H-H+H-H-+f-H-H-I-+++++ ··__·········--+-+-+-1 I I 1I I -....,-.~...- ""'--rl ---·-~··-H-I I I I I I I+H+I-I-l -···-·--·++I-H-f -MEAN o .•_._to't-._.--1--1 .-.'--_'--1··'.+-f---f-t-I.-'-'.,,-,.,_,.-.-.1···'-1--'-1-'-'.I·_'·_~_I_I~·I ·1_.'·-1-1 -.1-.-1--1··1 _·1_1··1---1··I.I.I--_I_"_I~-I._"_._ ....--_.•--._.(-'--1--1--1-1··(,.~.- ·.-1 •••_~_._••__.._·1-1.-1 __.··1-.·"'-1-_1-_1·_1_1-'''_1··1·_1-_1·-·,-I-l--I---4-H- It I~w;r l ~sl1lU ~r ::t-~~1-j~~lnt1ll~~fr -;'-1 :lfllllfmfli~: •MINIMUM ~l=OBSERVATION SUMMER :WINTER BREAKUP 0-DL:IIALI V-VEE CANYON G-GOLD GREEK C-CHULITNA T-TALKEETNA S -SUNSIUNc SS-SUSITNA STATION I'!"C 1.'i l.el:ion en Lab 1 isheJ I DATA SUMMARY -CALCIUH (d) FIGURE E.2.43 _I I ~-- ----------_._-, PAr~AMETER I HAGNESIUM (Hg)QISSOLVED,(mg./l .) ······-·-·-_·-···_-··_·,·--·-l-I-I-I I I I I I H-I++-+H+f--H+++H-H+H-~-I-~~-l-~I I I I I I .J-.I..-I·-I-I.ti ·t·'t·I·l·'m--EI·"···'-'l"·"-E·'j-I··\-EO'-EfWI1-'·I···'·[-'·I'·EG-'··'·"·I--'-'·"'·.__...."...........,........-...-....'............--......--......1---+4---+4-....LLLJ.1.l_.___._.._ .__._...._-... ._LtLlJ.Jj±tt .-f-f-I-+-l-H-~-'.....-~-~-~.,.~.-...~.-.-'.-... 10 .•...-._.-..•.•.•.•.•-1--1--1--1+1-1-1-1 ~+HT+....···-~-·_·-~-_·-~·+········-·_-···I++-+l-t--t-·I-+~-f-I+I+I -~.-.-_.-'--~+-I-H-H++--I I I I I I •MAXIMUM .............-•.-~-·-·-·-I I I I I I H-I-H+I--'!'·I-+-l-l+I··I-F-I--+++-1- -••.•__•.0._1·_"_·"_1__1·I .......-I--I-I--H_I-...-...-•.-.--I _.......6·_-<11·..._.__1.-...-..-.·'·'·'·''''-'····''''-'-''·'--'''-'''''-''-T''-·'--l=l=i--+='l+1 I I I I I -MEAN ti ...T:'._-...•-.·_,~·--·-,··~-·-~··-·-·-·-·-~··-·--f-H~-1·-H+~I+1 ..-.+ ....~ITl j T.L1.TTJTITIT1J.Tr.~·"·'~·_-- •MINIMUM _1.-4_1._11_10._",_.__I ......~••--.-4_1_..1-1-t-".+-+'.I'-I-••-.-t'-.I-~-f-·.J+I -•..--·-+~..·-f-H+~I- ...-.-.-.•-~-~•.•-.-.•-.·I+I-I-·I-t ++--.....-~.- o I~-I-I-I·I-I-J..-..J.+l-H I I I I I I I I I I I I I I I I I I I I 411 I I I I I I I I I+I+~H+~H-+H T I I I I I I I I I I I I I I I ._--+-.-.-~-~.,-.·-·'·I-H+-t-I-I-I+f--I-I .•........_..•_.__.••-f·-I I -I -1·1 •·.-1··.··.'.-....I .....-•.-.-•.-f .........t-••~-I--J-f--I-...J.- •••I ••_.__•__.~••._•.~._•._.._t_..-....-f-l--f.-.I._.I ..~_-J--J...~.I_.J_L-L-I_.I._l.-l-_.._1 __.I_-oI._L_l-_I_.._.._,..·.1 .I_.f .......-1 ..1._1.-1_1 _...._.•_.•_...··.f__._1--1_.--.f __•__.._...._....._... .·l.~.·~:~~J~~~~lll~i5~·llll¥f:r~nll:ll1~i1lrfTlii~t lrl~ltl·.·'-I' SlJMl~En :WINTER :1:ro·I~I·1D1~]'uIJmTL6r.I ill _k ..;[_.±. BREAKUP #=OBSERVATION U-UEtlAl.J V-VEE CANYON G~GOLD GREEIC C-CIHJLITNA T-TALKEETNA S.-SUNSl-IINc SS-SUSITNA STATIOH ['ld cl:ite'cion established. DATA'SUMMARY -MAGNESlut~(d) FIGURE E.2.44 -_._--------, PARAMETER:SODIUM (Na)DISSQLVED.(mg./1.) -._~- -··-·-·-····l-+-++-H4-++-~ 30 1-1-1-1-1-1-1-1·-·-·-_··~···--~-.-~~.~.•-•.~-"~-14+·1-1-+ ...-......•.•.•.•-.._-~··-I-+·l-l+H +1-. 20 ·.-.·-_I-.__I_·.._..··_,·~.._._._••_._.._·_1_.....__·•.1-·..-I··1--.···1-...-1 _-.I-•...I-f--H-.--t-f. ......-.-.-..·..·-·-··H+H-+-I~+I --.-.-.- -..--.-.-~.-.~..,.~._,-.-.-.....+-t--I-t-l-•MAXIMUM H+J+H-I I 1 I I I I I 1-+-1-1--1--1-1--1-+-1--1+1-1-·....··-·-~·~-~·H I I I I I I I I l .H_'_._...~·.~+H-+-H+t I I I I I I I I I I -•..•-...-I,-.•_-...-I-l-J--~--{..-I--I-_.-I.-I-~-'~--.+.....-..._--i--...--- I-+I-+-I-I-l-t-l-I·I-I-I-I-I-I·H--I-I +-1+H++=f··... --.-_._.-a·f+++++++-MEAN 10 ••••.<.•'-:1- -•.•-•.•-.-,-0--.•.•-,-l-l-l--+-1 •MINIMUM o .•,"-1...1-.--...",..-1.·.•...••I_I ·.I_.~__I_I._._·I_._...·.1··I ....._..·_.~_•.,·.··I-I.I_·~··I··I-_·_'·'_t ...• .•-<-..._••-••I-J.-...j-l-l-l- .·r.L··~J~~·Ifl j ~~~I.~·r~~I']Jrlll~ .L..Ll I I I I I JlutIlll t 1:'1 SUMMER ~lt4:'1 iT:1tl~111:·~r~n·I:l-f[ WINTER l·~1=~·~·~I~li~-~~j·:~:~~tj-~I ~F08SERVATION....__..._·7 ...~-._._......-~.-. BREAKUP 0-Dt::IIAlI V-VEE CANYON G-GOLD GREEK C-CHULITNA T-TALKEETNA S -SUNSUINE SS-SUSITNA STATION [lu crilcrion established. DATA'SLJMMARY -SODIUr·\(d) FIGURE E.2.45. ~__••o .__i PARAMETER I POTASSIUM (K)DISSOLVED.(mg./1.) ••..•~-I..-I._-I_I _I '0.1_.·1_.&_.1··•..1.-'_•._._.__•,_.•_._1 - 1 .1-_-.-•• ...•~.-.-.•-•.~..•-.•.-.-•..•-~--·_·+-I-f-l-l -.·-·..··_~-.-·~-.-~-.-H I I I I 1 -~......-.-.~-.-I I I I I I I I _.1 ........_......-1_1 __1_..-...t-........-I-.+--+--t-·+-t-·t-t·-1-.J--I--I--l--l--l---J--.l- 10 -·1.1.1 ..._ 1 ••I_I .•I~-I.I .•'·1·_'•••,1_1_..1_.1 ~'_.'_I..1.-I ••--0 •••_1_..._._.1-·....1-··1_...._1-1-·.·.1 ..,-•.1 ••1_1 --I ••'~~I-".·1 ·.1-,••_.....1-_...-I ··1.-1-·'-•••·-...~_-I-..--·- _01 __••-1.··1··-1___......_.__1_-14.""",-"-..-1 -t -I··'·-1·--'-...--t -I --f.-+-I-t--I--I-l--j ..•_.•_'.'''_'_'''_1 "-I-·I--f-l--'-"-"·,-,-,.·-t ··,--t-t·--t-·t-I-6 ·r--t··1'-1-f--I.-I +J-..'1.-_-1 ..•__0-..1-_...._...__._. •MAXIMUM +-~--t--+--f--l._I_I--I-.....1 -._..._....I--._....~__I -1-......- -1--f+H+H+H+~'-I-H-I-+-I-I+++I-I-I-I-I+H--H-H-H-I-I-l--.f-+1 -MEAN .,.->-.-.-I-I-+~l-lt:I~t1Xl-I-I-I--I+-1 'I I I I 1--H.-1-~++-I--·.-._-.- •.,.J.••~....._.-.-.__~_I--I--I-+-1+1-+I_ -..,-.-.-.-~-~.•-.-l--I-l--+-I--I+I-I-.f- 5 I-l-+-J---J-l-I-l-I-l.-I~-I-I ..1 _1 ..1__1_-1--&_1_1-.1 •.I_"_I-_.5._I_l.-I...-I_·'-i ~I -I _._...·1 -1-·.--1-1 -I _1-'"-I -•.- ..•..1-.•···•.1.1 .•__1_1_,.,,_1-._•._1 ••_•.I ..I •.'--1-'--..1--1 ••-_".-'-1-•.I_.._•.•._~.•_•..•--.··.•·-1·-1-.··········,....··0-.-.-.1-.--1-'-1--....·.-.-1 ..•_1- •••••1-'-I _••1_._••~~_••I 0'_'"-1 •..••-•..,"•.•••.•_1 ..'._••_-.1--e_.I_'·.__I _<1_,_•.•••••.·1 '_.1_·'_'·'I ••..•.1-.',"-..-_.•.-1._1-1--1 -1-·•..,.-1-- •.MINIMUM o ~•._•.•.•_..--·01-.~I-_1··-1 _._.~._Io_-I·~'-I .o._~·.~·1._'_1_·1,..-'--1 .I ... BREAI(UP 1~I:.lt1 \;11~:lnl~ITIT*llllltilll]'iQI ; SUMMEB :WINTEB :i~JJI.I ~II w. [)'I]IP ~-I-:tt=OBSERVATION U"l>EII ..\lI V-VEE CANYON a~GOLD GREEK C-CHULlTUA T-TALKEETNA S -sutlSHlNE::SS-SU81TNA STATION l'~ll edler-ion established. DATA SUMMARY POTASSI UN (d) FIGURE E.2.46 --::..-;:-::.-. PARAMETER:_PH --'.-- '~+f--/-.-.-•..•-.- ._-----"-,.--< --::--H++-1-I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I H-+-++-H I I I I I I I I I I I I I I I I !I I .•-.'-'-~.H--I-I I I I I I I H+-f I I I I I I I I I I I H--f-++f-H-f-H++++-I-H-H- -·I~·I-.•.I-•.-•..+..•-.-_--I-I.-.--f-H+H-.-t-f-H-H-++--f.-I -.~._-t-+1-+-_.-.'-.- f---I--H-1I--I--J-.f.-.'_4-_6_·""··+--41 -._....._1 -1--,__6_ ..._.•_.~...•..•-•...•.-~-.-+-+--l-++-f-I-+-I-l-H-H A 8 7 .- -_._-=,;-- .......•..•...•.•-J+."-+-f--...-t-+..•-.•..•-.- -··~·_-_·-·++t++t-H- 'J rl-["EEffi--'·1-'-"]·'['fH--r I-t··....- ._......-_..-._..- _......_a.-._.... ..,.,~'_• _••·4"••.,.___•• •MAXIMUM -MEAN •MINIMUM 6 I-H-I I I I I I I 1-+-1 I I I I I I I 1 I I I I I I 1 I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I +I I I I I I I I I I I I I H-I '~II~·lilltHti~·I·;rl; SUMMER DI t If l'I~~lgn1~" WINTER 1~11 rIUI{lUll m~r:fnl~;t'~t OBSERVATIO r~ BREAKUP D-OEllALI v-VEE CANYON G-GOLD GREEK C-CI-IULITNA T-TALI<EETUA S -SUNSHINe SS-SUSITt~A STATION A.I'lDL:l~ss than 6.5 or greater than 9.0.Shall not vary more than 0.5 pH unit frolll natural condition (ADEC.1979). E:;tablished to protect freshwater aquatic organisms. i:lA'''A SU~VUVjA~V -PH FIGURE E.2.47 r-..:::::::=-=-~--=---_.-'~--..::--.--.--..-.::.:;::--~ 170 120 PARAMETER:HARDNESS.as Ca C03'(mg./1.) ._---,--,-""-,,,,-1-1 I I I I l-t-H-+++t-t-I-H ..'1""-\"""'1"""'1-[[[-1-'['[1--"'''''1'LTJ-I·:I·IJ'·.J:j~(;"'-_ . ..__._._-L.__. - -.~.-[t -.--[~- ._-_...-....-. o --.--...-.-.-.-...---..-.-.....-.--++l-f;- •MAXIMUM ..-.-.-.-.-.-.-.-.-.•.~I I I I H .-...-·-·..·-_·-·-I-I-I-H+f--+·I "-'-Hof I I I I It t-H+-t+t-f-i+~-~~-'--""'- -MEAN 70 I+++H-H-H I I II I I I I I I I ¥I I I I I I I I I I I I I I I I I T I I I I I I I I T I I I I I I I I I I I I I I I I I I I I I I I I t-H r-1"-r-r-·.l1,-r-l--'·-1--1·l+-t+l-H-t-- "·'·-···-I-+-t-~t- --.---..,.---··~·-·--·--I-I++-' .1-...---._...._.._1_•__.~I_ "I:-I-H-t-t-t-f-I •MINIMUM 20 _0,._·1_·..._._.··._.·.-1--I ••+t-H--'-....-·...-..-.-..·-.-.-·.-...-.--I-I ...-..··1_"'_ ....'III.la"LI74l~t~·f'·16~·1-·11~~·~llfltl~lll~~'llf1l3Icr.1 wl"$r r ---tr-,~:'1$1"-r If-:'l ~l*ttitj~ti -1-1--I-I-t-l-··•-•....-.- SUMMER ..•_...-.-.·-H-H+ :wn~TER ...t2'I--tt ,·'t ~I"Jtl'I"$tt4ftjrttt·l/l~ .•.1::I~{{~••.~ff~f ~fi.8Jti-ttItl~ BREAKUP 4l=OBSERVATION 0-OEUALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATtON Nt>cLi terion established ~·j()llll;1l1~LaJ.s have variable synergistic effects with hardness,dependent on the prevailing. llcIL"C!lIi•.:SS in the water.'rhe criteria fqr cadium,for example,is 0.0012 mg/l in hard water i1lld lJ.()O1l4 11\<]/1 in soft water. DATA SUMMARY -HARDNESS FIGURE E.2.48 -,_.c=--~...::=::----0-_'---.::::--- PARAMETER:ALKALINITY as CACa 3'(mg./1 . ) -.-.--_.----·--·-I--+-t-I-4-1--+-f -•..•---•..•-.-•.•--.-J....-~-+---I---~-I-1 1-(5 ........_........._......~.•.-.......~...~__._•.._..~_.•_..-+·...-·1-_.._1·.,-..--H-l +I__,_~__.._t,__ ..·-·-··-·-·-·---·-_·--·..·~·_·-····-·-·-·-··--·--I-I+-~-+-I--J....-~-I-H-++·+-+H-I I I I 1++4+-1 -~---._.-.-...._."·---I·-t-f~ -~·········---·--+-+-+-+-+--1-++++ 125 ..-_•..•..-4·-·..··++-1-1...++-+4- -.·..·..·•...·_·-·..·····--···--····_·_-·-··_-·..-·..•..·-·..·-1-1 I I I I I I I +-~-I--1-~-~-.-,--.-~..-.-.-.•MAXIMUM -t I I I I I 1++-1-+++++-+-1-++-1-1 I I I I +--H-·'~'-_·"-·-·-~--- --·-···.-.-~-.~-.-I·-+~-+-I-I-I--I-..I..I ..I-I·-I-I-I-I--I..f-+++-~.-.--.--...•_..-._.~-....- .75 H-H I I I I I I I-·-·-·~··- -~-+++--~+I ..·--···_·--·_·..-1--+-4-1--1-+-+--1-.....-.-....-- 'H-I'f -1-·1-1-H-H-++-H -MEAN 25 --~- .1--1--1-+-~.•-~.•.•.••-.......- ._--......-.-...-.-.-.-.-.--.-- ·H~H+I--f·f--~--I-J-H--1--++·J....-I-·1 ..-.--•.-.-._...._.-.-.-·-_·...·-·-··-·_-_·_··-·..·--1-1 I I 1 I I I ....-~•.~•..,-t -,__I -l-H---+-4- -.._.t-._.-••-....-.··'_-·"_I·~t__t--'..·+-t-t-..........-f-H •MINIMUM -...··-·-·····...__·-··_··-·---I~-t+l I I I I I-H -.-•.-•..-•.•-.•--_.-......--.--.-.-1-·H-I-H+I·I·I--1·I--I·I--I·I-~--I---I--~-I·-I-J....-H-H-I--I--1-H~-+---I---J....-J....-I ·.·;~·II~l=i~f.n-;i~l·lf~tf1lfl~·:I~I~~~fj·.~lf!~rff1=11-I·rl~I~31~]:;·g:tl·:[{ft·ll!1f§~~l=08SERVATION SUMMER .WINTEH BREAKUP 0-DEIIALI v-VEa;CANYON a ..aOLD GREEI{C-CHULITNA T-TALKEETNA S.-SUNSHINe SS-SUSITt-lA STATIOtl :·~Olllt!-/1 or more except 'I:lhere natural conditions are less.(EPA,1976).,------ I,::..i L...llll.ished Lo protect freshwater aqua tic or.'.Ii!lIisms. DATA SUMMARY -ALKAL INI TY FIGURE E.2.49 --------'----,----- PARAMETER.TRUE COLOR,PLATINUM COBALT UNIT -l-+-I++-t-._~.-.-..•_- .•_•.•..•~•._._._'-"'-1·.'4_'__'_t-.-.-J-.-..I.-I-l-l 150 -1·--._._.·_._t_..-..._t-..."'-"-_.I-..-.-H--f+H-',,,,,. _..__.._._.__"'_~J-...J..-J -.-._1 I i I I I I l-l \00 ···-·-···-···-·+-H-H-t-H •MAXIMUM -·-···-··-I-H++H-H-H~..p''-H+I-I-H--H-H-H-H-+H+H I I I I I f-H+H I I I I I I H+++++l-H++-H I I I I I I I I I I I I I I I I I I -MEAN A_;.-50 ----.-.--.f-.J.--.l.+14-l-l- •·•.•·._.·._·.._1_1·1 .··.·.··.···,.-.··14....L.J.-I-J· H-I-l+I-I-.I-I-I-I-l-I-I-I44~l-l-I-l-l-,-.-.-~.-,-.- •.MINIMUM _.-.-.-•.•-.-.+.LH--I-I+l-I I I I I I I -l __e_'_~_.__-·I-'·'_"_·"'1·-'-"-·1-I -'._'_-'--11-'-'-'-"--'-i-H-+-J-l· -.--.-.---.-.-~_....--.-.-.-0-.,.••-.-f--I-+-~+I-++·+-+-l-l-+-l--lJ-·I--I-f--l·-·-•.-.-~.-.- -I ~·--~=trfJI+~-···--·- _.._._..•_._._._._._........·_,_._.__._I-+-I-~I__I-I__I_·I_~·+_l_I-I-I--I-I-l-l-l- o '-1--'-•._._.....__~~.....-I--I ··I.-e • ..-•..•-.-.--.-1-1-1-1-1-1- --.-.-.----l-I-t++-t-l~.:::..1)1"-'-~f'~9'-_.--r-.--- ----.---.---1\-,,~I..'I_'--·I~I --.'--.1-·'---h _.'.-~.._.-h'-Irl-rl -:.~~r:L..."_.1-·.-+._-.-----"~-.iL·.•'". .•.f1 . . . . - -j.(--.-fl------_!~ .::=~~=.~1I.~f.\"..:=.-~:.~.-=:~=.~~-.:~f:·=-;~~:..-'_-,-~=::.:.-~.-..--~=~.~:~---.::-.-::::.=I~~-H SUMMER :WINTEB BREAKUP ~l=OBSERVATION 0-DEUALI v-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINe SS-SUSIHIA STATION Shall not exceed 50 units (ADEC,1979) l~:~t.o..lblished to prevent the reduction of photosynthetic activity which may haye deleteriou::j . (:tf~,cts on aquatic life. I OAT A SUMMABV -TRUE COLOR FIGURE E.2.50______________________________________________J -~ 3 2 I --:::-- PARAMETER I ALUMINUM----.LA 1)_DISSOLVED,(mg./1.) -·-·-·-·-·-·-··~-~-·~-·-I I I I I 1+-1-1-1-I-H·4-H+I+H-f--I+I-H--H-H I I I I I I I ---.-- •MAXIMUM -MEAN •MINIMUM B --?-0 I-H-+I I I I I I I I I I I I I I I I I I I I I I H SUMMER WINTER BREAKUP *OBSERVATION D-DENALI V-VEE CAN'YO~.G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION A.No criterion established B.A limit of 0.073 mg/l h~s been suggested by EPA (Sittig,1981). This suggested limit is based on the effects of aluminum on human health~ DATA SUMMARY -ALUMINUM (d) FIGURE E.2.51 20 10 EL::.-0 ~ PARAMETER I ALUMINUM (Al L __Total Recoverable (mg./1.) -~-·-·-·--I I I I I I I I H·I I I I I I l-l....t I-H-H-+mH-\V-I+cJ;H-t+I-T-~-4;-I-l~~+I-H·1bI I ~I I d;++rt:-I-+-t"-I-I~--HsR1 I I I I il}~I I T I 1$I-ISSH-l-.-._-•..•.'-.o--I---1~r: ~~···,__w •MAXIMUM -MEAN •.MINIMUM *OBSERVATION SUMMER WINTER BREAKUP D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE:SS-SUSITNA STATION A.No criterion established B.A limit of 0.073 ~g/1.has been suggested by EPA (Sittig,1981) 'fhis suggested liinit is based on the effects of aluminuIl\on human health. DATA SUMMARY -ALUMINUM (t)FIGURE E.2.52 .-- '-..:o~,---==:.- --I .~---..--------~.....-=---~-----.-..- PARAMETER'CADMIUM {Qg)DISSOLVED,(mg.jl.) 0.003 III II IIIIII1 II11I11111111111111111111111111111111 11IIII111111111I111 rlll rm O.002 ~=a=annna=t=S~±t±tt±ttttt±ttjtt!:§fffFfFfFm~:a:anna:t:E~:S±tttttJ A~ 0.00 I tttttl±twttttl=l:t:t:m:tt:m:t+t:tttt:mWmW:tt:mttt:ttttmWmW:t:t:tt:t::t:t:~ A-?- B --;;-t_-t-Hr-H-H-H-t-t-+++t-+t-+t++-t+++H-H-H-II-HI-HI-HI-H-H++-1-+4+4+-++++t-t-~+1--I-1-+j1-l-l4-l-W-I--l--W-W 0.000 - •MAXIMUM -MEAN •MINIMUM #=OBSERVATION SUMMER·WINTER BREAKUp· D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION A.0.0012 mg/l in hard water and 0.0004 in soft water.(EPA,1976) B.Less than 0.0002mgjl.(McNeely,1979) Established to protect freshwater ~quatic or9a~isms, DATA SUMMARY -CADMIUM (d) FIGURE E.2.53 ,-,- '-~.-.....---.-~~~~.~",;-----..;'>~<:,-''~~;..~..~- --.~-----,~.'?~._--"....:::._-_..--',~~ 0.02 O.OL ~O PARAMETER I CADHIUM (Qg)Total Recoverable (mg./1.) --_.~-~I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I-H-H-H-H-H-H I I I I H-H-+H-H+t I I I I I I I I I I I-H I I I I I I H-t-H-l+1 I I I I I I I I I I I I I I I I --'-'--'-I-H-t-H +t-H-+++H+t-H--f- 'H+matttmwmf~~H-H-+H~-<h+-HH-~-H5S1-H •MAXIMUM -MEAN •MINIMUM *OBSERVATION SUMMER WINTER BREAKUP D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA S.-SUNSHINE:SS-SUSITNA STATION A.0.0012 in hard water and 0.0004 mg/l in soft 'water (EPA~.1976). B.Less than 0.0002 mg/l (McNeely et al,1979). Established to protect freshwater aquatic organisms. DATA SUMMARY -CADMIUM (t)FIGURE E.2.54 "-._.----------- PARAMETER·LEAD (~b~_DISSOLVED,(mg./1.) -------------------------- .._~---- ~0.03 0.02 0.01 0.00 _o-·---H+H-I-t+H-1 I I I I I I I-H-I-l-I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I-++~+++-I-I.-._.._.- -·-·-d:Jt-hhl-l-g-I-I-drtt~-H-,H-hb+-1I I I th I 1+H--H-I,It I IJ I II I I!I I I 1-J-rlrH+1 '.l.1 I'"I I I I I '"I I!I I I •MAXIMUM -MEAN •MINIMUM #:OBSERVATION SUMMER WINTER BREAKUP D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE 8S-SUSITNA STATION A.Less than 0.03 mg/1,(McNeely et a1,1979). B.0.01 of the 96-hour LC SO determined through bioassaY..(EPA,1976). Established to protect freshwater aquatic orgqnisms. DATA SUMMARY -LEAD Cd) FIGURE E.2.59 ,__I -',---' _l ....,._-/ PAfiAMETER I MANGAtlE.SE _(Mn )__(mg,/1.)Total Recoverable ,-r-r-"'r-rn-r-t-1.S~ ,H-I-H-H-H I I I I 1-l-1·,I·-I-I-t-·I-I+{-t I I , I ~-t-t-I-I I I I I , I 0,ll±--m8Bm~mmm:tffi:m~mt=t±13ft±±Ett±tmttjjtmmmtmm o.~III/I 11//1111 II 11'11 II III11I1I1I I11I11 II11 II I 1I1III1II1I III11I1111111111111 -·-·-~-·-·-·-l-+-l-+-t-I-I-l--++~--++II I I I I--++-t-I--I-l-I-I-I I I I I I I I I I I I I 11 I I I Ft1IIIIIIIIIIIIIIIITllllltlllI I I I •I I I I Ii I I I I I I I I I I I I I I I I I •~I •IA'~Olllllllllllltl -H-f\++A-f-l..lH-Ii)-!-+Q-H-4+h-m-l-H-l-t'\-H-fH+f\+hH+t1-++i I I st I I I HfH I rI I I rI I I Ii I I '"I-M I I '"I I I •MAXIMUM MEAN •MINIMUM *OBSERVATION -~'!l H-..y.H·<li~-t-t-J.-I-:.--~I~lj~I~~~i1+mTmt1-sp~~~ SUMMER WINTER BREAICUP D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA S.-SUNSHINE:SS-SUSITNA STATION A.Less than 0,'05 mg/l for water supply (EPA,1976) Established to protect ,water supplies. DATA SUMMARY -MANGANESE (t)FIGURE E.2.62 PARAMETER I MERCURY eHg)DISSOLVED,(rng./1.) I-H-I-++H-I-I-H-I-H-H-l I I I I 14--1+1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0.0002 I I I I I I I I I I I I t I I I I I ~I I I I I +I I I I I I I I I I I I I I I 'I I I I I I I I I I I I I I I I I I I I I I I n I I I I I I I I I I I •MAXIMUM -MEAN 0.0001 A--=-I I I I I H--t--H-H-t+H-H+~H-l a.0000 I I I I I I I I I I I I +I I I I I t I I t I I t I I I I I I I I I I I I I I I I I •I I I I I +I I I I I I I I I I I I I I I I I I I I I I I I I I I r-l1l-n-,,-1 Irlll I.tH-~-H-.i I I I I I d1l I n I 1,Id I,h I I"I I I I I .Ja,-H-H-I-ih+-hh I I ""I.lt!I,"I I ,"I l.leI I I H-H-I-+Ii>·H\f'-H-$-t+¢-tt=t-t+$-HSSH-H-I-IPi+V'++G++<H+T-rH-HSSI I I I I ID I I 'W'I I (Jj I lit I I T I I ~I ISSH-l •MINIMUM *OBSERVATION SUMMER 'WINTER BREAKUP' D-DENALI V-VEE CANYON a-aOLD CREEK C-CHULITNA T-TALKEETNA S.-SUNSHINE SS-SUSITNA STATION A.Less than 0.00005 rng/l.(EPA,1976). Established to protect freshwater aquatic organisms. DATA SUMMARY -MERCURY (d) FIGURE E.2.63 PARAMETER'MERGUR~I~)Total Recoverable (~g/l) 0.6111 II I1II1I111111111111 I1111I1111111111111111111111111111111 III1II1111111111 ---1--.-----.-.-10-..-..--1--1-1 I I I I ~ +/+H-I-H++++-J++H-I-++I-H-J·J··H-+-H I I I I I I I J II I H-II II I I H-+-H--H II II I I I J I III I II I II 0.4111 III III1I111111111111 111III1 1III1I1111111111111111111111111111111111111111 O.21-H -!-+-H+1-I I I I I I I I I I I I 1-1-+1-1 I I I I I I I I I I I I II I I I I I I I I 1I I I I I I I I I I I I I I I I I I I I I I I I I I I A.-..,>- a H+H--I-hl-I--m-H~I-',IH-H\H-frt-H;-I I I I I nH-flI-H\H-RH--frt-HI~1 I I I I r'll-+--RI-H\I-H\H4H-I--f\I I RI I I HsSH-l+I-Ib-H->¥+Hli++d I I T I I ~-HsS1 I I I lib I I ~I I di I I e I 11"1 I ~I IS~ •MAXIMUM -MEAN •MINIMUM #:OBSERVATION SUMMER 'WINTER BREAKUP D-DENALI V-VEE CANYON.G-GOLD CREEK C-CHUL'TNA T-TALKE.ETNA ~-SUNSHINE:SS-SUSlTNA STATION A.Less than 0.05 ~g/l (EPA,1976) Established to prot~ct freshwater aquatic organisms. DATA SUMMARY -MERCURY (t) FIGURE E.2.64 PARAMETER·NICKEL {tli)DISSOLVED,(mg./l.) tA 0.004 •MAXIMUM MEAN 0.002. •MINIMUM 0.000 11~ -·s·H-t-H4-H~-HSSH+H-~++di--l-l--11I I T I I 'f;~1 I I I I f)I I tV I I iii I I EI:I I *I I t I ICR~ *OBSERVATION SUMMER ·WINTER BREAKUP D-DENALI V-VEE CANYON.G-GOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE;SS-SUSITNA STATION A.Less than 0.025 mg/l.(McNeely et~al,1979). B.0.01 of the 96-hour LC 50 determined through bioassay.(EPA,1976). Established to protect freshwater aquatic organisms. DATA SUMMARY -NICKEL (d) FIGURE E.2.65 r~--_,_I PARAMETER·NICKEL (Ni)Total Recoverable (mg./l;) 0.1 •MAXIMUM -·MEAN o.05 ~IIII I IIIIII II II IIIII II I !III II IIII II III IIII III ITI IIII IIIIIII IIIIIIIIII IIIIII A > o -dl-t+drH-1+t-k I I I I I mI I mI I mI I Iii I I.h I Ii I I ~I I I I Iii.I 1,1.I I,ll I 1,1.I I .1.I 1,1.I I.li I I I 1-I-H-I-l·lI>H·\fl-H diH-d;I I 't I I $-H~I-H-I-HIH-+-SV-H-l!i-I--kH+-~~1 I I I I 6)I I'V I Illi I lit I 11"1 I $-HSSI-H •MINIMUM *OBSERVATION SUMMER WINTER BREAKUP D-DENALI V-VEE CANYON.G-GOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE:SS-SUSITNA STATION A.Less than 0.025 ms/1 (McNeely et aI,1979). B.0.01 of the 96 -hour LC 50 determined through bioassay (EPA,1976) Established to protect freshwater aquatic organisms, DATA SUMMARY -NICKEL (t) FIGURE E.2.66 ·._1 PARAMETER.ZINC (Zn)DISSOLVED,(mg./l.) -'-'~-'~-'-I+H-t-I I I I I ~ -~._~._._~t=t-t+ft1=ttt---r-tT-tt·-H_-Hi-t-t-H+t+H+t+t+H+t-H+t+H-H+I-H-t+J-I-I-++-I-+t+l~~ 0.2 •MAXIMUM -MEAN 0.1 •MINIMUM A~ o =.¢!th PI I i'I I 't'I I 't'I I'l'l I'l'l I I I I 'I'I l.p 1+11-1 I '+'I I 'I'I I 't'I I 'of I I I I I 'f I I , I I f I I '+'I I '+'I I '+'I I '1'1 I I -'-'-~-'-H-H+H-l *OBSERVATION SUMMER WINTER BREAKUP. 0-DE 1'4 A LI V-VEE CANY ON.a-aOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE:S S-SUSITNA STATION A.Less than 0.03 mg/l (McNeely,1979) B.0.01 of the 96-hour LC SO determined through bioassay (EPA,1976). The suggested limit is based on human health effects. DATA SUMMARY -ZINC (~) FIGURE E.2.67 PARAMETER·ZINC (Zn)Total Recoverable (mg./l.) 0.20 II I I I I II II I I II II I I , I I I I I I I I I I I II I I I I I I "I 1'1 I II I I II I II I II I I I II II I II I I I II I I I III •MAXIMUM -'~-'--'-H+H+H-H-I I I I I I I I I I I H-H-l+H I I I I'I I I I "I I I I I I I I I , I I , I I , I I I I I I J I I I I I I I I I -MEAN O.IO t._____ .,MINIMUM A --?-H+H I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I o -'-'-'-~'-I I I I I I I I I I I I I I I-H-t-l-H-H-H-H+i I I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I _.'._._.~~illimtfffiEi$_as=t=t1i-=fstt:t::I=t::t~tw:ttt~#:OBSERVATION SUMMER :WINTER BREAKUP D-DENALI V-VEe CANYON.G-GOLD CREEK C-CHULITNA T-TALKEETNA S,-SUNSHINE:8S-SUSITNA STATION A.Less than 0,'03 m~/l (McNeely,1979). B.0.01 of the 96 -,hour LC SO determined through bioassay (EPA,1976). Established to prot~ct freshwater aquatic organisms. DATA SUMMARY -ZINC (t) I FIGURE E.2.68 17 t A 14 PARAMETER I DISSOLVED OXYGEN,-(mg./1.) !§-. ---" - . - -....-.---- .-.-.-----i - - --.--.--.IXI.L1_LLUtlILLI LU.J .IDIIJ:±itL~_-LLlLL...._.._._ ..•-I_..-.-..·..•-~-_·_....__f.-I_.·~.·.•--...-H--I--I-4-+-4. "·-~-·-~-·~·H-++++-I--I-I-I I I I I I I H+H-H-H-+++-I+~-I- ·~~-4-+-t-l--I-+---I-+-I-+---I-+-t-++I----~-·--.-~.-_. -.-.--...,-,-.-~-...--'--'--~-'--'-'--H+-I-+-~+ ··_·..·--·-·---H---H-f+H-I--l-·+-I+1 I I I I I I H-H ·1-1-t-4--l--I-I-I--I-+'·H--H-+-++·H-++-I-l •-.-.--·--I-I-I-H- 12 -.-1 A __I_.--J-.l-.J..-J.....I.- -.--.-.-.-....-......-~-.•-H-I-+.I-.•--.....--.-~Er+ll~ftrlEt:F1-H=lTL'-'-~-- -I-- -'-~-'~-H-f+H-H+'H •MAXIMUM -MEAN 10 --,-+..~.~-,.-._- I+~I-~I-I-~·-~·-·-··..·--·-..·-··-·-~-·-·-·-_..-.-'--'----'-~~--~-1-'I+H-I-+++H-++-l 8 ·I-+-+-l-l--I-I··-·-~.~....--•..-<-.-.- _...--.'I--I-~--'.-~...-.~.- 1-..·..-..··1 -I-.....~.-I--t-~~~-....-'--1-·1-t-.1_...---1·_f.-._··~-+_t--...·I_·.H"__._.~·I·'--1_--1 -•.·..-1.·•.·.....· I-+-I-++-H·I -I-I·H--I-I-I·~+++t--+ ..1_'_._+__•_._.....•.~._.._....._....._._I ., - <.._•••-.-.--·-l--l-H-I-l·•MINIMUM -··-·..·-_·_·..·-~-..-I I I I I I-·-...~-·-·-··-·· nI~rITI~-r~r-rt~::~ SUMMEB --··-·...--+-H4-·-I--I---l-l --·1131·~I·-·t--1-1~~11-~1'181-I'qrl"-It!~:1~rI141~rl-1:1-~-t:1 rrfln41·t1[r-l~T-t~~r·:$f-:--roo ·-l·t ~f:':Tllfr$l'---l~rrr ~rll=t=FrlFI~L-. -WINTEB BREAKUP ~I=08SERVATION D-LJEllALl V-VEE CANYON G-GOLD GREEK C-CHULlTUA T-TALt<EETNA S -SUNSHINe SS-SUSITNA STATlOtl A.CreaL:er t.:han 7mg/l.but 1.n no case shall D.O.exceed 17rng/l (ADEC.1979). l;~;L,d;Ji ::.;lI...,d fol'the protection of anaurolllolis and l'e~id~n l fish. DATA SUMMARY -OXYGEN J DISSOLVED FIGURE E.2.69 PARAMETER:D.O ..PERCENT SATURATION -~.-.-.-•-.--.-.-•._-1--~-t ++-I +-H-H-H-·I-·H-I-I-I-t·-I·+ -.-.•-•.-.-.-.~.4-+--J~~ -··'-'·'-.--H-I-H-+++-H-I-I-+-t·++1 I I I I I-H-++-t 120 I·+l-J+++IIIIII _..._.---...~1-1+++11111111111IIIIII1111111111 _..~a.-a..,-••.•~.•_._1--.-..-•.-.-....'--1--.-'--'-'..-'-I - I _•.-I •·1-I '-.-4-1·-.·,.····._.__4-·_I_.....·a....I_I_'._._I--a-.J.-I--+---J++-+-~ ...·-····-·-I-I+-I-~ A--~ _'_010--4_'I _1.0'.-....-_.._--.._-••-'-I-'~--J..--I--I.-.J -•...•-.-.-.-H-I-I-H- ·~+f--I--"'H-r++I-I-H+++H·I·H·-I-H-H+H ·1··1·+1-1-1-1'+I++H·-I++-t-l-4+++++I+++H-I-+-1-•..·•.··•.-..·...-...--t-I+H-j-....-.-t-·....-...- 100 ":'1--+:r-++-t-l-l-•MAXIMUM -.....-~·-~-·-·-H~++-I·++++-+f--HI I I I I--I-H- h'__'__'h'_'-H-I-H-H---H-4+H-H-1 I I I I I I I I I I I I I I I-~-l-+-I-I-·I-H+I I I I I I +-+-1 I I I I I I I I I 1-+ ...•..-_.-•·~···-I I I I I H-H+-1 -MEAN 00 ..·1 1I I 11I 1I I I 1I I 11I 1I I I I I 11I I ..•..-.-.-.--.-.-.--...•-.--..-·--I-·I--I-I-I-~·.-.•-.-...•-.-•••. ·1-I--~-1--t-·-·-·_-·..-.....-.-...-- •MINIMUM 60 -.-.-.-·-----·-I-I-H-I-I-+-l-l-I -t-I-I-I-I-H++I--+--H-I- ....-...-+-.....-,-..- ,..-1-1--1 +-I-f- ..·····-·-··-I-H-H-t .-•...-.-...--..·--·--·-·-~·--·--·-·-···--·I I I I I 1+ ._-.-.•-_.•--.--.-·-·-I--I-I-H- .-.-.-.··-··-··-····-·-~-~··-··-I-I++·+-+ -·~·-·-·-·--·-t++t-+-I++- -'-:'~]$i-ftl~ltFI~f~l~lfITll~rt n;-I~llff-t·t·ltH~nrl:';-f~l"fr~~l~rHl1~$1'-:lF08SERVATION SUMMER •WINTEn BREAKUP D-VENAl.!V-VEl:CANYON.a-aOLD GREEK C-CHUl.ITNA T-TALKEETNA ~-SUNSHINE SS-SUSITNA STATIO" A.'I'h~COllcentra tion of to tal diso1 ved gas shall no t exceed 110%sa tura tion at allY point:.(ADEC,1979). l::sLiJbli~lll:~d for the protection of anadrolllous and resident fish. DATA SUMMARY -b.o.,%SATURATION FIGURE E.2.70 PARAMETER:NITRATE NITROGEN}as N,(mg./1.) _L •••----l--I-I-4--+-+-~.....__~L_~.'"._._...-.-.-~...-..---L-....~.-.-~-+-+--l--I-.-.-~.-•..•-.~....-•.-.....-~-......- ~ .-_-I--H-I-I I I I I I .1-+-1-++1--~~-•.•_- ...._Lf;,tr 2 ..-..-....-.-.-.-·--_·-·-··-/-·I-H-I-\-I++I-H-H-I-+-H+f-I- •MAXIMUM -._...-.-··-~..I-+H·+I-+I--f.-l-..J-I-·•.·._1···•...1._1-...._1 _-1-'"-1-_.........-._.,·1 ._ H-H~~~-H..I--H-I-H+I·--H--i-l-I ·-1-f--H+··-.--.--.---.-.-.-.- - ..."'--'-"---~•.·-··-J-I+H-+-1···--....--.--·l-t--I-.++l--l ·•••·.-.--.--..-'--'-'-''''''~-~-'--I-I-I--I-I- -MEAN •MINIMUM o 1·+++l+~H ·1 I I 1I T I I 1++4.·1 1I 1I 1I I 1·1 1 ~I I H--I·-t-l I I I I I +++-I+l-H-+.-H-T I I I I I I I I I I I I+-H 'ellfH tll HI~'-I nWIIITf~!if l:f~'Jtl~~It n~~lfj il:IIIII~lH~fJf§jrfl 4tOBSERVATION SLJMMEB .WIN"fEIl BREAKUP D-DEUALI V-VEE CANYON G~GOLD GREEK C-CliULITUA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION Less Lhun 10 mg/l (-\-later supply).(EPA,1976). 1:;~;l..dJi i:;ll<;<!1:0 pt'ot(;:ct water sUl'plie~. DATA SUMMARY::.·NITRATE NITfWGEN FIGURE E.2.71 PARAMETER:ORTHO PHOSPHATE.as P,(mg./1.) -.-.-.--•.~_.~·-l-l-f-I-I---l-l ......•.•.•.•-•.-.··•·..--+··.-t-.-I,-H4-I--I·'··I-I·-I-I-+·- 0.6 _t ••._._.,._•••_........_+._._._.nt-t--t_..--f'_t_._.··-t_+-H I I I I I +-1 -._.-.-<-.-H+1-+I-H-++--I-+-H-H .\\-\-\"\-I-r ·\··\-j-t·tJ·4 u·r-·j·-j·!··j·1-I-j··1 tj'·/'·j'-rt [[- of _.• _•••--•.----l-...,-_.---.-_.1---•.---1-..~- 0.4 .•-.-_.-·-~-l+·t--I-++I·~-~-··'·-•..-_.-p •MAXIMUM -1-+++++·H-H-I-+~_<_4-_~_'- •_to.I_1_'.of ,·1 ••__1_"'_"_'_'-'.--.'-1'•••t-,-"-'"'l~'-1-·'-I--t--t-l-f-I--f·+-f _.-·.-.--+-.--I-~-t+-H-I I I I I 1+1-+-l+++4--....•-_.•-.-··-·--·-·I-+4-H-H-H·++-I-+-l-I--l-l~- /' .....•-.-.·~-··I I I I I 1- -t-I-f-I--I-+1--.,-~'_4_~··~_'_ ++H+l-+-I-+H-+···--·-.-.-.--MEAN 0.2 _t .....1-·._1_1··I •,'-6-"-1'·-f -I·...--.-•.I-f-.-.·--t--t-f-I-f--l--I-l-f ..•..._·._.._.__I __.._-_-I··I·~1'1-1-·1-I--t--t·-t -t--I-.-.t-·t-..-I-4--f-.-.-+~_·'-..II-I-'-' . I ..._.'_.1_•.._..._......._1_·••·••..••_._~.~0-...._.....,.-"--"'-"-1--1_..-.-•.-...-1.I,·I ••'••,1--'-I_"_'__-I·_-"'_I~"'I.'~.'.••'-_-I--'-"'-"''''--..-...--....-.------•MINIMUM ..•.•..•.-··-·-·-1·1+-1-1 .·._-_·.·_~.·~-I-+.J-+I-I-1_,"__.•_..._-1-._'......1_'..1.•.'__'_"'1_.'._._.~·'__I_.-_·.·•••--"'1_._·.._.1 __._I ••1-.........·- 0.0 LLL+-W--W+!.~4.t-wmlUf·W+W-f-1rTllfll.IITT"IT+.w+.rnrlrnTI ~+-f-.:1=~llnTTITTTllll hrl~:I~t lrl~~1[=~..:1m-fff.j:llli*I:IJI~r:tI[ll~rnfmfl*tlrfm~~l ~~OBSERVAT ION SUMMER :WINTER BREAI<UP u-DEriAlI V-VEE CANYON a~aOLD CREEK C-CHUllTUA T-TALKEETNA S.-SUNStliNc SS-SUSITNA STATION rid cdL:c::rion established OAT A SUMMARY -ORTHO PHOSPHATE FIGURE E.2.72 .._..._._..•_-._.~._._.__....",.-.-R.-.--...... ...__..__-._.-.-----.4._"----.----.--.------..----, i 10.Susitna Reservoir II.Cholitna 12.Tokosi1no 13.KrC)1o..;.Trapper Creek 14.Kahiltna 15.Yen1na' 16.Skwentna 17.Heippy 18.Alex.ander Creek FIGURE E.2.73 o 10 20 MILE SCALE t't$lr;;;r~;;Jr..WA: LOCATION OF TOWNSHIP GRIDS IN THE SUSITNA RIVER BASIN Koshwitno Sheep Creek Montano Creek Eli Talkeetna 9:Chulina l.SUSlfno '~.r-i ~h .Cree k Willow Greek Little Willow Creek -_._--_.._.__.-_...~_...~--...-_._..._--_._.-._--~.-..._.-~_.-_--._--~---.._-_.._-- ('>Cantwell ----_.------._,.--_....---_..._----._--_..--._._---- ANCHORAGECOOKINLET SUSITNA RIVER DRAINAGE BASIN \ ~·._/.N·. ,~,..f-~.. ! (, L\ Fl ,\ r'l Jl ( C\ i{j If\ rl r1 I II'.~I I o 4 SCALE t:.====~=~e MILES "' ·FIGURE E.2.74 LEGEND C~~=:J"BORRPWI QUARRT LIMITS NOTE I ,....P INDEX SHPWN ON FIGURE 6 I SCALE ."-LOCATION MAP 'Ir i J i j J. l- f' !I" \ ') 1 II IIr; r"..,~- ";-I ;I ~. ."',(~"'.\ 1"'":/. i '-----.,i WATANA SC1RROW SITE MAP i ~:~\.•-. \\~'"'•.••i)..JBORROW (.':'1 '!.T.E f\\~L1 -j ( l ----- I,, / I 1:3 8 0000 00 000000oU1~O ~I'-0 C\J ~r<'l I'-r<'l C1l <i) U1 r<'lC\J-o ,000000 __________.(r::: ~rrrrD I i I I f I i I I I I I I I t .I ,----.,j, NOI.L'I1A313 8M'J . o 10% .WATANA 'WATERL£VELS II, 1 t ,~., \ WATANA DAM CREST ELEVATION 2200 1600 20 1400 2000 zg .!;t '>1800c·w.......J w· ;...·F i'.;'"I. f'II:,:.:.'",:rt'" It) 9 '/..15 *'-u w Cl 0:: ct:r 0 l/) 5 FIGURE E.2.76 WATANA WATER LEVELS·AND GOLD CREEK FLOWS DURING RESERVOIR FILLING 1991 1992 TIME (YR) o l.J..-=.cILLJ-.-l--.L...Li-LJ-.-l....ILl-L1~--L-LL..J-l.-.L._~..l-.L.-1----L.....J.-..l-.l-.JL...-L-=--~....L-.L-!---..L--.L..-~..L-..JL...-.L~~ I~O 10 %EXCEEDENCE PROBABILITY ----50%EXCEEDENCE PROBABILITY - ----90%EXCEEDENCE PROBABILITY f'" !I !t ,',:l ) ~, I I \ ) :. (50 ! I 40 ..--""(fl y u.-CDI (J u.'\ 0 \(fl 30 j 0z \<t (fl ~ 0 J: ! f- Z-20iw (!) \a: I <t J: (J I (fl ®0 i 10 ( o 5 10 15 20 25 30 LEGEND: _®.- AUGUST 1958 FLOWS FILLING SEQUENCE I,AUGUST 1958 FLOWS -WATANA MINIMUM STORAGE CRITERIA VIOLATED FILLING SEQUENCE 2,AUGUST 1958 FLOWS -WATANA CAPABLE OF ABSORBING HYDROGRAPH AUGUST NOTES: I.WATANA FLOW 84 %OF GOLD CREEK FLOW 2.RESERVOIR FILLING CRITERIA EXCEEDED AUGUST WITH SEQUENCE ® 3.NEGLIGIBLE C'HANGE IN DAM HEIGHT DURING FLOOD EVENT 4.MAXIMUM RELEASE AT WATANA 30,000 CFS FLOW VARIABILITY NATURAL AND FILLING CONDlTIONS DISCHARGE AT GOLD CREEK I \ ) l .. FIGURE E.2.78 i ~ BPGr:-WAI t:.e.Aer::A.~.... \4 1'2 10 8 ~ \.L \ Z (p o tiili 4- ill 2 o l1(15lJTWY ll~AL\N I=C~ TI2\euiAr;?:'{ VlATEQ I-EVE-L ql2A\I~L CEFtrolTE-D BY TRIEUTt->..ky "'S~rnJA RIVE\< WATi=12.U=VE=l- .~ 100 Fk"4Uk:-~E::E-.c::-,q 00(POAD-40-(PO--50 -2.0 0 20 DI5TAhlCc I~F~E.T ~J-4~MATIC Cr n~E ~FFEcr or-=Tl-~E::::lJSIT~A RIVLl:.-:.O~A l'(PICAL -rKIp:iU~TM?~'Y MOUTHI._________~_=___=_~__:..:...=.__:._____!. MICRO EINSTEINS PER SQUARE CENTIMETER PER SECOND I I I \ .....CllIoOO '"......CD~O .....•uo '"..w ..f"r ,I ," 0,~I I ~:I '".....~lQO ,I LEGEND .....n""......CD ...Ooo DATA ---0---- -~---~----- ··6············ ----0---- ---0- STATION STA.II STA.7 STA.4 STA.9 STA.II DATE 28 JULY 1982 27 JULY 1982 27 JULY 1982 I~JULY 1982 15 JULY 1982 LIGHT IN SITUI I l EKLUTNA LAKE EXTINCTION MEASUREMENTS FIGURE E.2.80 NOTE (I)TAKEN PERPENDICULAR FROM MAINSTEM FLOW (2)ESTIMATED MAINSTEM DISCHARGE 1200 CFS @ CROSS SECTION 5BO ) 610 52000 34500 23400 17000 13400 9700 WATER SURFACE PROFILES AS DETERMINED BY HEC l! UPSTREAM LOCATION 600 OF SLOUGH FLOW Ii ® / l t-=' ;-1' MAINSTEM---~'\. lL.I ~)SUSITNA RIVER r z I'I;LOUGH THALWEG 0 590 _Jj THALWEG i=;g f \.PROALE (II w ·...k-MOUTH...J )w SLOUGH WATER SURFACE PROFILE (2) 570 127 128 129 RIVER MILE 130 SLOUGH 9 THALWEG PROFILE AND SUSITNA RIVER MAl N STEM WATER SURFACE PROFI LES FIGURE E.2.81 l i \ [I I J • ~I I I 2070 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP WATANA RESERVOIR WATER LEVELS (WATANA ALONE) FIGURE E.2.82 • \ \, I, \ \ \ FLOOD . -::- M~~sPILlw",.()JTLET F"'CILITIES ,Ii .~pp£/lolTlNG I I Io -f,-J 1'\',..rOVTflDIt [7', ~ow ...., 'j:-,ir", V n J It'-,-[wEc";ENC'I'~\I 0f'E<1U.;\ I I ,,, (.<,1I·1\,'\.'c,II ;I I - I II I ..... I ~""p(ti:1/~""Y ,--OPER",T IJ--.LPOWE ....~AND ovn..n ~.....CllITlElU...T f\Ill CAPfoC4TY TlET FJlFILITIES \H"E .....TlHpo 40 140 110 •.. U rooo ~ ~I~.. 910,000 YEAR FLOOD t:l ro t'IT"':(OAn) ~'IO,OOO YEARFLOOOT' !1 Iio o " .' .... [ .-£••U w,l 2193 '\I~IHFLOW Uc!:WINCoum.ow C"",",CITT /\WAlH sPIllWL Of'tRJ INC (.....TOI'''''IIoIFlOWI I .' V . Kt-OVTL£1 F,.cIUTlES AT fUU.C~TY POWC"HO\IS£'~OVTLLT f'ACILITlES ~[I\"'T"; (t/...TCHING 1HF'l.Dw1 ..0 1---f------,I---f--......;+---I-----+----.--1 tiN o ZII4 el96 uoo Zl~ 140 1----11--4---++--++--..!--......;+.-----l ItO I----II---H----+f--~--..!---+.--- ·tllll ZZ02 .. k. U 100 I---I----Ctl---I-+---I+--~I-~.---;I----I ~ ~IIO ....o. 5S'0 -,,~YEAR FLOOD (IUOA'ER) 10 e eo t!l 1W£Il\.CYSI ,.~YEAR FLOOD (lu....CRI Iio f\ '\ :,--u.- j 1\ V .\J1-----~I:!'!I- lI'l '1 '. !OUTl£'f ...c:IUTIE~,~·c:AT f'ULL e-errr ~~_IKlUSE&IC)I OUTL,[T fit.CILtTlES OPfJIAT.; I (W",Te-G ~l______--:-:~__-e.:c.,---'" { 2 - '. ,.'. I ,., I I, I i : I 1 i i {lUX .SEl-2193.0 ,'/~I i i Ii "1 t\, I II \ I ·I ·-c /.OVTlCTUC..,TIES 1/~AT ,.ULl C-"'ACITY ·~E"~ANP OVTLETl'llCIUTIES "Of(.....T1HG (wATCHING IlIFLDWI o to -220 2200 ~4O.. ..o. UllO oo !:! tlU zo;::219~..,. '"..J '""219Zo,. "'"::ZI90 " _2196..... ~ --_--:._----'--------------------------------~-:----------------------.....,;.-----'--------~---------_.__._--r r.·\l [I (1 fl I rt I fl I ~~[l '1 'if, fl r( I fl\. ':fr IrI 11. l WATANA HYDROl,..OGICAL DATA SHEET 2 FIGURE E.2.83 I ( I I .IJO I 165 I eo ~ -I 120 - I ... ufOS g 2 I ~.a.. i ~ I 10 I ..-.5 i XI, )15 I 0 I I I 4 I 17 J.j r..-- / 77, I 1/./ /I / /~/ .//I //I I ~, L005 t 5 10 ZO 50 100 1000 00.000 _ ._...I"£RlOO (YE"'~I INFLOW FLOOD FREOUENCY .WATANA INFLOW FLOOD FREQUENCY FIGURE E.2.84 E.2.85FIGURE '.,'. ANNUAL CURVES WATANA "•~m _~_ .,.0"........c....-.t ,__Lt.0I'l (_CI'.. OCTO ..... "'.+--.--+--~-;_,.__;-_T~_T_-+-_,_-+_- MONTHLY AND FLOW DURATION SUSIT'NA RIVER AT , ----"-POST _PROJECT ':0yt.'~wIt '.at C[_(•.af(O .1tOII to ~I "'_KCO'tD .,..nOllIC:ll"."0 'I.Ul..r~'Cl AYJ••.II-l IIlJIIT!'IL'f 'LOW'&--t:j il ,I I,Ii "1, i i[ !i fiQIf.S: ~~~~•~.m ...Of '..I ~I>["••[[~\.II,'I 000 nelt_1I .....T.M ..... .'··••... !• #:='j;"'-i-~i" -'".:'.:'!?=:~~....:'q=-.::.~':- ---'.-:-'-~:.~~.'.-=-P )1O:O.o~oo~io.o.:o ...0",.....'/1,.(....._"lOuA,~Ir;(JIll .ltllOl:D i'·/4.'UaU.T iJ.r ~•__l..:'-.. :--t- i j-i ~:_:.~.~::-',=-;;:i'.~~--;r~;.':n'-L~ ,:;=.;-~\-=-=-":..':'3=..::...::=.~#:..,=f,_~:E'~-=F_'~.. ",'__-':-:,:c;...,:~>=J;..---:-:<_ • • -to -.;fir,,....-IK ....,..uo...(IIUC" ........UA ..Y .JULY •:.;.-'--:.-;'1-:<~l :..~.:...:- .,=."--.--'4 .:::::~:l:-~-j J.--:,7'~~~;~~~~=:f :-~-'-:-'~~·'T o ~~~~~~ft ~_~ ,"00-'....DtlC0lAll5l 10000"~LltI 011 '..::U'" ~:~""1 :: i ".ic,.".:.-f----· "-----r----~_.- ...---------...I..-_-t .._._ .;.- 1'0 _..to .......,_..."'.....-;M·'L •••"eu.. -..ANU V _. ....--.."•••"10(,_......,_",.. HDV.M ••" ------=--1-------- -------i 1'O_-oIllD_7O., ...0'".....,1,'I'1i('-"':'0t.I"'1 ....e-'ICIIM. .JUN. ~--.-.-~-.'--,~_,+,r-.--'--.-_+r--"-=-.++-.."~....:.-=----i:p::::f--"'.--i"~:_"'.1'-_ .. ~ :•-.~~._.~:::'n-~-_;- •;:+.'.''.""io'-r -:>~""-'-~~:-~=--"i f..·.~i·=I':_:~-I-~-'-::i"-'~1:~"_I lIr-11 t .:........~T":..,.:;-_ I--'-- .~·'i~~-;·-·:~~~r;=~-~~i ~~. 1••-....~--II====::1 .-~. fl 4,: f/ ..•....j >tl ,.'1' t'! I ["I I fJ I fl I II I fJ lf I f'·I .i ( fL E.2.86FIGURE MAY ••_•_•e...."--~.~._.... acTa.... _.i:~; ;_Ba.~ I ji I _. " I i !, MONTHLY AND ANNUAL FLOW DURATION CURVES SUSITNA RIVER AT GOLD CREE K ~:'i •----"[.~["'Lo;.; ,I ...-•I.- ..-~- M,.fIlCH .~•.~:--0.,':--,---.~=-..::.--===,.:::::__T-.=;:•• .~..!.~:,.: i l .-• ..." I··I '*T ':"~.~- : I ·r ·f . !·I·!I I ...,..,---,- _E'•:.!'IIiI." ---1"---.-,----.-.---4--- ..."........, ...",1_~IWk.L11 GIl r.ut.u O_C_....." -------~~~~-!~~~~-~ --";:C0~I~{~':;;;~~·';~.~S;0 ~~~'"'-:~,,~:-c-~-:-""'"j ~~~::===-=-:::=..~=:: ":• '",i.,:4 !-. :'.=!-_=~..--:-::.-:~i:.=-;--:---=_:! I.•~-",.~-fIB: -;------···I ,.....-_:.-_-:.:~ J --- ••tD .".,,,_....c--..-.......a.h _.-.- .nn.v ft;..ec:s «"p;; ....I_......_.........~.r.•••CIta ....."'" NO".Me«iI.', .IID_._._....1'_.........,~....._ ,",UN • ·:iII''--"--- • ••.•.-.•.'-"!I:"\':-,,-~--'• .....,Y'-e _~~•..,... J,.NU,.II., .~.::.-.:-:=-:-r..=:...~-j-;-;:-~-;:~=.~---;....=.;~....o:..:i..:.-:::.:._-.--7-;;-~-. --:---t -,__ .........,-.-:~....,.- :::--~~,-;:;-,-='40 ....;.=_.~~:.. ~~=~}fi~~~ J ........... "'Of'T_~,...ua_~ MAY .-.....,•......u.a ... aCTa .. -....:--!" !. =•• .. a. a. 1- FIGURE E.2.87 MONTHLY AND ANNUAL FLOW DURATION CURVES SUSITNA RIVER AT SUNSHINE ---"'.'NQ.II:C"1 ,~,': ----CASE C ---------:;- :.~..:..-:~.~·~I "".....L '-=.,----r :::t,-;-.'\--....,'-.u...ae _~:••"T........'I -.-. . .."_"_~'........r:•••_.. ANIIlIUAL -.--.-.u ••_~•~n ...r-...c.__.~.Lf.'iii 1MlU." AU_U_T ..._---~•'iji...••10 ..•f ...........~l"1MMU.If••~ ~MA"CN ! ' ....-.. .........-.-........-.-- ••c ...... =:-~-.::;:-:~==.,7-=-.:;:-;~~~~""'..:::_-,:i.~-:-;.-~= ---.----:--::':~--==:::;--=--- "'~~~~••010 ..... ....~~I~_~ ··,......u .....Y JIII!II!lIM!.......,.,...,.-......-....u..a.e_......., ofU\.Y '-JANUA"Y ..-... ......-----.~...--Nav.",_" •.~~~~~~..,... .-. . ...ftI ...~.--.u........ ,i . I • : i i'__•.··••• .1 ----'.'-+---m. .-....-...~........r~_~ ~UN. ···•: I -. :i,I E.2.88 .. -'-,-_.-:'"'T-.-'""• FIGURE .......... ......,...........'1a*.I..a••-----. .AV ~•••••c 1lo .,r_.ec-.,:t.~...Ilra-,.. aCTDFI_" MONTHLY AND ANNUAL FLOW DURATION CURVE S SUSITNA RIVER AT SUSITNA STATION ·•"'-1•==:=::;=-==-==:=--7~,_--#-'~~T-I~~.I '. .:· I.~UlIn"t:I ".".AT[D .aou 1O·Y(,Ut'.(~ ",MIUottiCAL.'UTMlSJttl &fIC)1"\lLATlD AV'[....K'IIOtI'..L"~ ----CASE C ..-..,,~.........~..-...u.......JO '..~.... I-~.~-.-. .--.....Y_1if9C.~1-...s..IV.l-.:u.o' ....T.M ..... I • :. iilill.,··.~_u_._--_....,.-....;.,-..-,:-...~-"-:"':-.'. ---' J _~-"'--'...L...-__- • -t:::.:==t:=:=-_---'-- ,/~___t__--__l._.•__-+-_.------..+--_ ItJID •."...1D ,.1'':~I~n _1.1Cd"" AUDuaT .: -:-·~:;--r-~-":;'-~:"~"S::-P':'_-·:,• ~···•_.t.----1 --,...-t--"-~--:-~~~~--~-~~--~~- I I --<.--..........__~ ..~.~......,'........e-.....-......L ••_f-eu:" D.C.M .... ~IJIIIIIII I£• I •:. ; i ·1iII1IIJI ..111--illiflil• • _ •__e _ '.....~I--..u.......... ~ULV .:···· ..... .. ........-..-....u.D ..e-.:- ,"ANUA""". ..••• •'HI • ....~~ICIUIII,.U._'--=--·"UN. .... ...,.,.r.-..t-._CMlU.. Nav •.,.. I' 1_-_·······-11·....-----II. .. J,m~mm L _ .. I =.I II I [ 1 L. •I i ;; . : ;;""1 'VI'-I : ;:, • I .• .:,. ,'..~: .; I .:; . I I . 7'I' .~C f/\iYI I:' { ,. :I . ;- . ';! :I : • .,-: i •: ~;, : :;!. I I ~- • :.: I :~ ; I I I ~I ::;i I •: J ;I ; • I i I ;!;! ;:!I iii: i ;; WATER TEMPERATURE,DC 4 6 8 10 I''. I "II i :i • ill' I , •I 2 : , I ; ·..\, :'.\ .'".,\!Il~-' I :.I i I I I o 'l:f 'C::'f!='....Gl.NE 'RS.'.: f--.'-':"-~.L..J....'..;..'-t-'+-:-'~'...:..:-h-....:....~.++...!.'...:......:.....L..j.....::....::~i....:·-1-~--'-JUNPUBd.ISHEG I , · i !';:._.-+r-:._'....::---:---1~;.....:.-;....+-'---,--+-:--:---t--:--:--''1+-'-,---+~--i-"-~ · I I;••;:l • • •I ~! i I' [I.) i r /' I ' r I (1 I [I I i W\ E( ki '[r I f''I[:l [ l i [( [d f ' L I l WATER TEMPERATURE PROFILES BRADLEY LAKE,ALASKA FIGURE E.2.89 C'( r [' " I I, Li I ,~~''"I "I I f'[L ) NORMAL MAXIMUM EL.2185 EL2151 EL.2114 EL.2077 MINIMUM LEVEL EL2065 20'(TYPICAL) I FIL) MULTIPORT INTAKE LEVELS FIGURE E.2.90 WATER TEMPERATURE °C 3 4 5 6 7 a 9 10 II 12 2200 2150 2100 2185 MAX.RESERVOIR LEVEL 81273 I 81152 1900 IB50 IBOO 12II1098765432 1750 L-._-I...__L...-_....J..---JI---....J..----l...---.-.....J..--..L.----'---.L----'----J I I ,I'I :,LI YRn 81243 L,J JULIAN DATE B~SED ON 19BI DATA WATANA RESERVOIR TEMPERATURE PROFILES FIGURE E.2.91 302 FIGURE E.2.92 292 OCTOBER -- 282262 SEPTEMBER 252242 1 222 232 AUGUST -JULIAN DATE RESERVOIR TEMPERATURE MODELING OUTFLOW TEMPERATURE 202 JULY 192IB2 I 162 172 JUNE BASED ON 1981 DATA o 152 I 4 2 14 fl I I"r( . I fl I' r! ! [( f( [[ ii-r\ / -1! [!I ; l I L \ FIGURE E.2.93 .2 ~10 20 50 100 FLOOD FREOUENCY CURVE (INFLOW AFTtR ROUTING THI'O'.JG'<WA"~"U.1 REtuRN PERIOD (YEARS) DEVIL CANYON FLOOD FREQUENCY CURVE " I 1 I I I !I ;I I I :I /i 1 : ::1,i i 7IIII I , I I I --"- ;Ii-:-.- I I I Il I I I I I J I i -IiI I ! ,I ,IIII I I I '"I , V I , !i I ;I I,i ill'i I---,j I I I !AI-I i I:I l,i ,V ,, i I I !:/ : --f.---ri-1 III:.Io 110 30 I~ 60 120 ( \ [ [( ~id l ( l.\I II t'I ;\ I I I [ ( ,~\ ~~I ~h.I 2110 2150 2090 2070 2100 \r~ ,I "I,I ",/,/ \I \'/.I '\I-..\\I /"\1/1-MIN YEA. \I \/ \,/"/'v/ 2060 L.--_..J..-_..J-_-L...,._--L._~_-l-_---.!.I_--I._---JI--_J....-_J..-.---.I OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 2080 2140 2180 2170 .2160 2190 I- ~2130 zo ~~2120 .Jw hiI :.,( \ F:\ Fi ~I l \ (d [( l:( L WATANA RESERVOIR WATER LEVELS (WATANA AND DEVIL CANYON IN OPERATION) FIGURE E.2.94 DEC JAN'FEB MAR APR MAY JUN J UL AUG SEP .EDIAN .YEAR \\\ ,\ \~ " '\./ 'v"<"f.lIN YEAR i I i ; L,r i ( I ( I ( F ( r-~( i F( i \. DEVIL CANYON RESERVOIR WATER LEVELS FIGURE E.2.95 Xl ; 30 ' 10 e to TINE I[)I.YI' RESERVOIR ROUTING RESERVOIR ROUTING • :I 10 1:1 ro ~ TIW(1[).A~1 e lr !'O"'ERHOUSE ....ND /~~:.:tOLIT'ES ( •"-WA.J.wSCL -1-0:1 !.()--'~-I .'---I r--..r-'j r''i!',:-".('J,,l (0,' '-c -..---,..---r --~-·-i----- f"OoI'(~A.'" OUTLET r~aLmu CP£lUn~ ,0 "-u ~ .:. g l:i) J... 10 0 0 FIGURE E.2.96 I- I 0-:145... '",;.z: ;;~ ,I~...~ '''';j"~ c "0 t<45-4,:f. 'i"-i.1 ., ~1,~ r ..--_._--------'-,_..., RATING ,.10.000 HI.F LOOO IS to nw(l[)I.nl RESERVOIR ROUTING 10 DEVIL CANYON HYDROLOGICA L DATA Ir f'O'ol1:R>iOlr.!€.OUTL£T FACILIT 0 "NO W.lJW 5I'1LLW"Y Of't:R"T""," I '-.....X...!sEL.I-0:1 I t ft. o LO-_.JIIL-_-1fL--....JI5l--~to.L---JI:::l----'!Ol-----.J3lS T,WE loo.TS) .bESERVOIRROUTINGI1'10.000 YR.FLOOO ~o 1--'------t--=:J!...-c..-;'-+---+---+---+----,.-1 1;.00 .al--_-+--.J-.---t---f---+--t--~ 14:>ll ..."'0 "o ~ ......u ..= ~ ~14~.. ~.., d !1454 .~.4:11 ---..--_.._--------------.----.-.--.------._._.-.--_..--_. III.l"O Ttu€[DAYS) 1~t;,l~CT ~II<G' 10 10 III 10 T.oo(ID-OYSl PROBABLE I.IAXIUUU FLOOD PROBABLE MAXIMUM FLOOD I I~~S( OlITTLflfII----f--I>''-,WA.TO<HQ 1-~-t-'--~t--~I------1 IOlFLflfI D o 0 ltf:5flOOft £Lrv"'T1OIl 0 .lUJlws£l./£WEI'tClE~CT.~."5J SPILLWAY OPE:flATlIK 0 //r\\PO"'ERHOJSE ~E~IHG Ir'.\ 0 "\ \ z<0 -------+----~ :OtO -- .....0 0:-0 .- lZO 40 o 147 146 1410 1q0 8 zoo ----- o.. .....u i 160 ..I... ,.: ...IH [( (I fI l fl I -J lI ~[ I l l f( f( rl, II ~~(r I•tIl ,r'(-;-'-~; I 'f ..~ ~.§_: -'.-------..._"'-'it~.i..........._ •..c.a.__ -------.._T-e ~II-.,ur,__1;:-""_ ~~0-'.=~I ~q~.~."::~~1 _.'.f---i I. ~_.. ~=";'~""."'.-'---......;;:"j.....~.-= ~ -' : ....····· ....·,·,· -" •...J ~. ........... _.--,."-e ....-..c.~.-....••_tn:..u.- ••~T.M ••" ----CASE C (WATANA/OEVIL CANYON) i:i" r .; ~._::--J=-~.....;..1 3~f~:g-:=~....-~~. .•·:+-·t:: ~-.'···.~~1't~ 1I1I:"'~·~~~··'f.':""'·~_tf;':..~•..:.=---~-" .•f-""'T .;......!ti~~':.:-..~-~=-~"'"..==~~.."="'-F§.§ .~~ ••-4--~J -....._.- ------'~'\,.....''''''''C~-C--...c:._••UU..:,':..: = .....1----.·,..·• tfQI.U: •---_(·~(O P\..CM' ~---------------------- M ,'.eM ......--...-~,.,............c:_..'t~._II'flCIIII_. .' ~.:II·..·..-..···-11-.···.--_..-~II'.-r-- .......~-........-~_:...~-,. .,.- ~~?~+~i~,=ji-~ - :':'-.'~'-=~'.=Z:~H~,7:~~':;i ·:i--;'-"'-=:1..,~d. ~:-:-:::'--'A7 ~-~--'-"::~-~=:=:.:':L.":":::-;-'=. :--:-:::'.::::-:-:..=-.f-. ~,::."···:···-·II""'";;••-.~,.l~_...... -+-- --I ...oj I'''i:~:--.: L...:..--:-~v ...=.-....;,.:;.=-,.-l..r ~~<.!- ·. -..--...-....~,.......~c-.-.u:._'Ii"'" .'··•, ..~···"·~..,.--. .~~-.......-~~-"",- ~.-..--..:::......-~"::': ~;::c·--=:t-:.-~~~-c .::-.~.~ _=>.:4=-::.,......; .._-._~ ......"-.--':":..........._c~c_"'UN. ...........,UA ...Y' ~,'.=-~... : .'+---,:~',,:,;._..._.',..':.....c...:-;.;".;.':-::=.-;.:':_'~...;.,.r~~_;.;..~;:;-_-:...:~I-.::-...:.:;.._-_.~..;._:-_-'-..---...-"L"'''-C ~.--..u__l'"'".... : ...I·.,. .; •··r;...._ ••J-. ....f-.... ... fi I (I t T( I ,I \ ···.··r·-'" ..( i \~ :,'.if"\1.,. :f( t ...a.-..-t:1 ~w("l_e_au:."'-0-............. ir(.~D VI '..,.,I"C)...c....\.•••a ••"L.'U ....(......(.iIo(:W'1-.."'L.~ =-'.. .~ .~. ,..........,~.<.-.- ::>;;-- .,".t_ .. -: " I .'~._~~~~~-~:_~I,-.:t:-~f}.:.C~•.-I-:~=-~:..;::.~:=~:~~..;i=C~:.;::·=-·~..:;:·I.:-=:'-T---'''>_·,L..·....-I•.-.•:r-:_.~..--~~~;......:.-.c..~CHULITNA RIVBR NEAR TALKEETNA \ 'ILL.--"1__-_--_--_-~_'~_-_--_-__-_-_-.._-I-~~,""'---.-...,••_......._."",_..._..lit._,_cr __a .....--....--,,",,-...4 -.NOV..........O.C ..........."~N ....U ....Li FIGURE E.2.97 i I ~ ! I ........" --..-~-...""'t_~~....rca...w.uo ....u ..... OCTO .... ";J ~~:'.:"--.."j-"~:-..:...-~..---= ~j~~~~~:~(\~:.'i~--·~=j ~-~.~~~:~~~~..~~ ~......-i'-'~4 -0 .,-.-_.,-"...-........-L:-lo.o..-~,. -- .·~JlilIIII~I-•.-•---..'.-...,"...........c-......~I W .. -.--~--~ . ,--._2 ~._.-.~.::.~_:~....:-:'::::::=-::.i:-;::'':: J .:._.:.....1 __----=._ _,.~..:":_~__i._l-·__·-__'='_•••__-.-L __ ••.1_-I •• ~~:'_T~~5~~-__~·~_-~-~__=L·-~.=~~_~~,-_.~.~_~-= :-~-=-:=-_-~:.~:.::::-=-=-~,j~_.~:~=·l·:-----=-:-T.--:~j.-~....~:-:~.J":'~= _...._..._...-~jt~_A~~"_~;.'..~~..~..~{-----:-~~.-~--'"7'.--~~....'"'" "I • :---~};:.-.---;:-~.~ ___~i .:~.1-~'.- .,., ~: i •l·~lC'T '-Lo- \ '-----CASE C (WATflNA !OEVIL CANYOi~J L 0..--""-t-(&.l_t"UD .~32 YEARS .(C--DlID 0"_ISTD<II:IC6L ".D 1'_ULAto- I .11"'[·..."1 w.cwTIiIl,:1 'LOW1,I I MONTHLY AND ANNUAL FLOW DURATION CURVES-- SUSITNA RIVER AT GOLD CREEK 110.--0_." ....,'......~.......r.!f-.J"••__••«r.. ....T.M .... ·.·• ......"R,-~,-.,II-."~..-....-........,..~.•~•._f'.u.a_ ...+-----'---....---r--~-i--..,-_;_-_._-_T_-- ";]lIIii.•-_0-_._ h.,.~--~.: ·---1··.:....__ "]" I-~ ~:r -1--.-'--.-----~--- ...,-L·_=.'-.---~. :j =:;=~~~:_~~~ I -----~---..--:_- -~t~~-~~~1-~~~~.-d~--~~~;--. .: :~:c;:,1iII.~~ -:.....;'.~.,"'. :'c.:--I=.•::_~"1~-::~~.,":: .-;:i·.c;=j-' ..'··• •~_.-.:..-",.-'.--.::-=~~ ~E~~~-·~:i~'~--Ei'-~-~T~ :_~ .*':.'-~-·• "· .=.L...=~::-:=1.'•=-=-=-==-=l ==-=--=r ..-..--...-."......-....c.~.~••_,.u ... :.. !• .''._~":"':i=':'o _-t,- .:-.-:--t :~ ..~.._-'.......-'~-.:..-,.'.,-::,-,. :'-'~~'.c~~;~:,,~~~-;7.~ ..'~-----'--:j~..:~-_._-:~--:"-.::".:":-::=::--'-.-~-_:':-~-..,J____.,....::.~__~__:_..... ,;:-~------;-'--------=-~-.;-----::.=---:-;~..--.~~:.~;.:-:.-i'- --~~~.:--=--~:..:~.:-:=:--:3~~-_--:-~~~-:j_-::~:.-:~-:._-~:~-= .:~._,-,i-.......--:---·:-;·~'.:'--_-;---~.:...--~-....":-:--~-t...:..-,--1 ---,--,-~_•"-~-,l .;.-.... :~ -:·,·• 7':..•.~-u _:·n_~··j ·1'••"!----::--r---;c-..,-~-_,__-_;_-...,..-...,..--1'0 ., ...".'-e ..~t .-..-..}..••_••u:.... ....ULY ...J=-IRI~...------"_'....~I~••_I'.cu1ldl D.C.M ..... ..··,·• .'~~:::-::=;j:=~-:;-:-~-:T-.__....- ",''''''''.-..c-...._...r._rrUl..m !•... ~. .••-~u r~';:; -1-.1 _ .:i .-.-.~.. ,. 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MJo."CI-C :~~-;.r-~*£v~l-~~- •t "~~~;'~~~~ '-0"I~OoU~"r_-I.c,_"C'1I'" ","UDU&T .~•.._,..:....0-=._~'.---...•."'f-.::..._ -----_...._,,._•••_'.1.4.-. ••+::c.:.,......::....;.....::....;..:....:....:;.:..:=;.......:..:..:;-~--T...::.....:..;.-~-- a.c ......••... 111t--·~,..··~·.·~__&.=~=._;- -'_._--....~ "..;.-:-=='~-=;-~-;....-;~~_r:....:....=....-"'''''--r--":'"_'-.•.~.~:-.-;=--.:;;.§f....'"=i~'-:;-"':'-..:,....~--:.:::......:..=.:.=-1!111!-!-I"II'I~I-I'!-1·1!!1-11_'1_-1'-.·"~-~~---,.--=-~---:---.~--:'=:=--=-1-'='= ---""'---_.~.....-.. w 1='=..,'-"-.~':--•-.--,-",,~.•~.~-,.~••~-<.~ !• :t 9 •.,_.-=-.. _ __...:.__,;._ f '~"~.~,.~.~;-.,,~..~=~~,.~~,.!:~,,,~ 1·~_..j _.•..•_~;: ..-.••I·_..·,··t··__·--::-:.•.-_....:-:-. ••III _•._.._ ,..1'"~•.........u ......u ..... - I:~.;~~~~~::-~~~2·,~~:;~~E~¥.. !·i·Ii-,~~~~~-IIi-.'..,-'~~--~'.:~~, -.,.~ -_..,..-=-=--:-=-_.;...···-<;:-i·=:F-'=l~--· ~~.--~~:.~~~~.=:..~~-~::=-...::-:;.-~~...:..~.!-?=. '7.'-:-:·~~~='·~:;'-;O·'~-:-:=:j-+= ~.~-~-~t:-::=::::t~:··=-~~~~............. .....'.-.ol "&0(_-.(..........LI.e-111:'.'- "ULY "-"....-'1~L- -.-t-.""'!.- ...:-.- • -,.- #_'-~~.-~~~~~===,.-- ,==~.''-:='--'i:',·..-~ ----=:- ....,., , J .J:t '";-;;....:,;_:li~-~~;'-~·~;--=-;i;--'.~ J ~~;:~:,.;:::;:!;;':'~:.~:...}:.:..:~-...-----.".,,~~.~.-... ,,'1 ' :f-- .' r Jrl i I I I II ~I I r(:. ·1 /I If PRE -PROJECT POST -PROJECT CASE 1..;0 CASE 2 ..+ NODE ..NO.27 § 1'1.) § o I.i I I Iii I I I Iii I I I I Iii I iii I I I I i I Iii iii i I I I I i I I I i I I I I I I I I iii Iii I I I i I I Iii Iii w § 1'1.)o -;'§ o (J')-U'I ~§ ......... I o § 270 300 330 360 390 420 450 4BO 510 540 570 600 630 JULIRN DATE NOTE: I ppl =1000 mg!1 TEMPORAL VARIATION IN SALINITY WITHIN COOK INLET NEAR THE SUSITNA RIVER UNDER PRE AND POST SUSITNA HYDROELECTRIC PROJECT CONDITIONS FIGURE E.2.101