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HomeMy WebLinkAboutSilver Lake Hydro 1997Stow | = July 3, 1997 - WO we w9e DO) EDEIVE Jeerectteer) : if ov amie.) T UMS sur o7 agar LY Tous : - AIDEA , Alaska Ind ctria! Develasmen 480 W. Tudor and Export Authority Anchorage, Alaska 99503 Subject: Transmittal of Silver Lake Hydroelectric Project (FERC Number 11548-001-AK) Initial Consultation Document. Dear Sirs: This correspondence represents official transmittal of the Initial Consultation Document (ICD) for the proposed Silver Lake Hydroelectric Project, near Valdez, Alaska. Silver Lake Hydro (SLH) of Bellingham, Washington, holds a Preliminary Permit (Permit) from the Federal Energy Regulatory Commission (FERC) in Washington D.C. to study the feasibility and environmental consequences of the project. The permit was issued on November 1, 1996 and expires on November 1, 1998, at which time SLH intends to submit an application for license to the FERC. Under requirements of the Permit, SLH must conduct consultation with responsible resource agencies and the public. The first stage of this consultation involves identification of appropriate agencies and public entities and distribution of the ICD. We are mailing the ICD to you, recognizing that you, or your office may not be the appropriate consultation party within or agency or organization to serve as your agency’s representative during the licensing process for the Project. If you assign further review on this project to another office or individual, we would appreciate your informing us of the party assigned so we will be dealing with the appropriate person/office for the remainder of the licensing process. This ICD contains: e Project maps and land descriptions; e Engineering design and the proposed operational mode of the project; e Identification of the environment to be affected, the significant resources present, and impacts which might occur to those resources if the project were developed; engineering WwW H | T E WAT E R corporation 1050 LARRABEE AVENUE « SUITE #104-707 * BELLINGHAM, WA (360) 733-3008 ° FAX (360) 33-3056 2 e Proposed environmental protection, mitigation, and enhancement measures, to the extent known, and e Descriptions of any studies SLH might conduct, and the proposed methods to be used in those studies. Two meetings involving the public and resource agencies will be held, one in Valdez and one in Anchorage on or about August 15, 1997, to discuss the licensing procedure and to receive comment and information on resource values in the project area and environmental issues and studies to be conducted in support of environmental analyses. The publicly available copies of this ICD will be available for review and copying from the date of notice of the public meeting (at least fourteen (14) days prior to the meeting) until the date of the meeting. The final meeting date will be set after coordination with agency and public representatives. We are specifically soliciting information in the following areas, to be provided verbally or in writing at the public meeting or in writing no more than sixty (60) days after this letter’s transmittal date: e potentially-affected resources in the project vicinity including fish, wildlife, vegetation, geology and soils, water quality and quantity, cultural and archaeological resources, and aesthetics; e relative importance or value of the various resources, as indicated by local, regional or national use, economic value or special protection (e.g. endangered species); e management goals or objectives for the various resources and potentials for the proposed projects satisfying those objectives; e recommended studies and study methodologies for various resources or resource categories. SLH, in coordination with agencies and the public, will develop detailed study plans for all resources to be evaluated. We would much appreciate your input regarding studies after your review of the ICD, to help guide our study planning efforts. The section on “environment to be affected” in the ICD is based largely on surveys conducted in 1982 for an earlier Silver Lake project proposal. We realize that this information may be outdated, and intend to conduct comprehensive literature, and, if necessary, field surveys in 1997 and 1998 to update the resource baseline. 3 We would greatly appreciate, however, any more recent information you or your agency might have regarding existing resources in the project area. Please provide the information, if possible, at the public meeting. We appreciate your interest in and attention to this project licensing. If you have questions, please call Thom Fischer at Whitewater Engineering Corporation, at (206) 733-3008 in Bellingham, Washington. Either Thom or his licensing designee will respond to your questions or refer you to the appropriate FERC representative. Sincerely, (prs Fotavtle for Thom A. Fischer President, Whitewater Engineering Corporation and SLH SILVER LAKE Hydropower Project Initial Consultation Document FERC Preliminary Permit Number 11548-000-AK July, 1997 WHITEWATER ENGINEERING CORPORATION Please send your comments by September 2, 1997, to: Whitewater Engineering Corporation 1050 Larrabee Ave. Suite 104-707 Bellingham, WA 98225 SILVER LAKE HYDROELECTRIC PROJECT INITIAL CONSULTATION DOCUMENT TABLE OF CONTENTS SILVER LAKE HYDROELECTRIC PROJECT. ............:scsesessseresesssessssesscesssssssscesseeeseasars ii INITIAL CONSULTATION DOCU MEN Teer ctarescusetasuravselssecunusvoverebuedeveveesvsenteatietea ta ii Cee Oe CON EN eg ese rr eee ts eed LUNN LU Maal se MEME elem euaea eG ii ROE TO eee eee ete dese nace a aide etree aCe MEL aU aL Laney ae ee a GML 1 THREE-STAGE CONSULTATION PROCESS CORE Oo eee eee eee a re ee et ee aul PUBLIC MEETING AND SITE VISIT .........-...cscccssseisseestsssescnsnenesesereveesscenererecnenesenearees 2 THEE Eee OR Oe Coo cree erect aueeateurusueleanet sata tee alaeats cts cc anata ate 3 FREE pO CATO eee Huse teat e ta degae es stds MC cada I ee a 3 FREE Re eee eee ena MeL Nau scdsataueuedeuta ae uL eel EeULne laa se Rede a 3 SMALL PROJECT DESCRIPTION .... VARGE PROJECT) DESCRIP TO eee rae aee ata aun rata Menace ee ect Altemative Large Project Arrangements tit steal tell nual aaa etal 7 Storage Dam. And Reservoirs: citscsscscesscssssestcosseaeossoesenrnssesserensseunesestesaesaeaterseceanetecnersear 7 Power Conduit and Powerhouse Alternatives..........ccccseseseeseeeeeeseteteeseeteeseseseseseeneneee 7 Switchyard instream: F1Ow) Re|e2S6 Faces ee ee Mata anU So 12 TE PANSMISSION, LANG tees shaseseeseesecesscscvesueseesuceasty svete esessvacseavensussdeuucususnaasasasarvesuctesrsuetes 13 LANDS OWNERSHIP eee iiiauieunsdssclasaniuadeseseieabledessstsueenslesensueustaxteysrasueansuuacterasuastas 15 MARKET FOR PO Wee Ge ee a ore ees iisesstesacasssuesaveneeneesracsessustsueaectascesces 15 ENVIRONMENTAL RESOURCES AND ISSUES 16 AFFECTED ENVIRONMENT. ..........::scccsssssssssssssssssesesesesesscscssssscsavevssssssessssseeseeeeeeeenenes 16 Information Sources and Previous Studies .0........cccccesesessseesesseseseseesesssseessesesenseeteneees 16 Fee Ser Res CES eee eles Lela t dda atlLeatagMiltaueusudsouevenecussusaetesesetereueuts 19 Water Use and Quality... ecesssscsscsssssscssesssesesesssseseseseseesesesecseseseeecseseneeeeeasneneats 20 Geology and Soils ...........sccssssssssssssssscesesssssensessssssscsssseassesseasseserseseneaesesensorseeasossnesoestss 20 Recreation il Cultural Resources 2 Misual/A esthetic RESOUrCES iret eee Lene 21 EXPECTED RESOURCE ISSUES, PROJECT EFFECTS AND MITIGATION......... i FA CQUALICIRCSOULCES teeters esse nenstenseetnecancustenseatsecesevastanestnestsccatecsunsuensestsausasneesuseseseseacee 21 Waters Useland Ouality ee eee eeee eae nenacreneasenceserace eneat sangeet ansnsersseneetcee senses 22 PRETres trial RESOUTCES ee a eee Et nn Re eee eae reas 22 Cultural Resources Recreation ers esee tse tesnsccsestes Wisual/Aesthetics RESOULCCS ee Me sea eee casaneeeanstaanenceasncatsucacntents 23 Geologysand Sois|RESOUrCES Merete receerscccnenesuerstsccrscsncusnccsusasesatcestocscecuencavetcsedtes 23 eR eee oro ee or ea naa us nn eauseUueaTseenstatsneneaers 23 PAQUATICHRESOULCES ar antssesasernasereanencutararsensactearesessersacucesuscesercsuensest 23 METrestrial IRESOUTCCS ee UL Mataay teeter aanctietearsarseceestencnatesarents 24 Cultural Resour Ces ooo ea nabectacteurarsecsirersasearasesnscesarsursssescstsernsesnsaaaserssctezses Recreation ReSOUrCeS men ee ssssrenrensases Visual/Aesthetic Resources Geology and Soils ReSOurces....................c.csserssscsssesesesstesecesacacaceserorasasassncarerastsnessesssses 25 Water. USe) and) OUality termes eraser an ae suena aubasusneaaeeesnattaserancnsesencecucntcencast 25 ENGINEER TN Gee ee ee aiimnissecastensestacsasnsesise stveasustsensasescasessazrss 26 EI CEN STNG ee ee ere acaenesransresetsnscesarusacaensseearcereresnseuenorsestieesucanc ted iT Ree ee Coe eee ree aseeatenrachtenssrsnscarstststcnarstcuscansescccases Di iii INTRODUCTION Silver Lake Hydro, Inc. (SLH) has been granted a Preliminary Permit (Permit) by the Federal Energy Regulatory Commission (FERC) for the proposed Silver Lake Hydroelectric Project (Project), as described in the following sections. The Permit (FERC No. 11548-000-AK) allows SLH to secure priority of license application for the Project under Part 1 of the Federal Power Act (FPA) while obtaining the data and performing the acts required to determine the feasibility of the Project and to support an application for a license. The term of the Permit is thirty six (36) months, expiring on October 30, 1998, at which time SLH intends to submit a license application to the FERC. The name, business address, and telephone number of SLH is: Silver Lake Hydro, Inc. 1050 Larrabee Avenue, Suite 104-707 Bellingham, WA. 98225 Ph. (360) 738-9999 FAX (360) 733-3056 The name, business address and phone of each person authorized to act as agent for the Applicant in this application are: Thom A. Fischer, President 1050 Larrabee Avenue, Suite 104-707 Bellingham, WA. 98225 (360)738-9999 C. Mike Prewitt 1415 140th Ave. NE, #9 Bellevue, WA, 98005 (206) 957-1874 Fax (206) 957-4782 THREE-STAGE CONSULTATION PROCESS Pursuant to FERC regulations Section 4.38, SLH must complete three stages of consultation with agencies, the public and other Non-Governmental Organizations (NGO’s). These stages are: Stage 1. In this stage, SLH distributes the Initial Consultation Document (ICD), holds a public meeting and site visit, requests comment, conducts study planning, and distributes the draft and final environmental study plans to consulting agencies and other parties requesting them. Stage 2. In this stage, SLH conducts field studies and distributes reports of these studies for review. SLH then prepares and distributes a draft license application and associated documents, including a Preliminary Draft Environmental Assessment (PDEA) for public and agency review. Stage 3. In this stage, SLH submits the final license application to the FERC. Consultation continues during this stage, but is carried out primarily by the FERC in the process of finalizing environmental documents and obtaining resource agency recommendations and conditions. PURPOSE OF THIS ICD This ICD is intended to inform the public, agencies and NGO’s of the following: The FERC licensing process; The general design and operation of the Project, as presently known; Market(s) for the power generated by the project; Environmental resources potentially affected by the Project; Potential impacts to those resources, and measures currently envisioned by SLH to protect or mitigate those resources; and e The licensing schedule. PUBLIC MEETING AND SITE VISIT SLH will conduct two public meetings on the Silver Lake project. One will be held in Anchorage and the other in Valdez. The exact times and dates of these meetings will be published in the respective local newspapers at the two meeting venues. At these meetings, SLH will present a detailed description of the proposed project and its mode of operation, as known at the time of the meetings. We will also describe the environment potentially affected by the project and environmental impacts as well as they are known at the time of the meetings. A primary purpose of the meetings will be to obtain information on the potentially- affected resources in the project area. If you have, or know of the existence of, data or information on any resource or other feature of the project, SLH would appreciate your providing that information during or after the meetings. PLEASE SEND YOUR COMMENTS BY September 2, 1997, TO THE FOLLOWING ADDRESS: Thom Fischer, President Whitewater Engineering Corporation 1050 Larrabee Avenue, Suite 104-707 Bellingham, WA, 98225 THE SILVER LAKE PROJECT PROJECT LOCATION The project would be located 15 miles southeast of Valdez, Alaska, on Silver Lake and the Duck River (Figure 1). The approximate latitude and longitude are 60° 57' North, 146° 33' East. The Project would be located in the sections shown below: TOWNSHIP AND RANGE i __(Copper River Meridian) SECTIONS TILS,R&8W 12 ae) T10S,R8W 36 TI1S,R7W 3, 4, 5, 6, 7, 8,9, 10, 11, 14, 15 T10S,R7W BIB 2533 PROJECT PURPOSE Currently, SLH is evaluating two different purposes for a project at the Silver Lake site. The first would be to provide power to the community of Tatitlek. The second would be to replace the current diesel generation of the Copper Valley Electric Association (CVEA) as well as the Tatitlek load. If built only to serve Tatitlek, the Project would have an installed capacity of about 500 kW. If the project were built to serve Valdez as well, the Project would have an installed capacity of approximately 15,000 kW. This ICD presents two different project configurations, one to serve only the Tatitlek load (termed the “Small Project”) and the other to serve the combined CVEA and Tatitlek loads (termed the “Large Project”). The Small Project would be less costly and would presumably have fewer environmental effects than the Large Project. The Tatitlek loads are currently met entirely by diesel generation. CVEA uses diesel generation from about October through May to supplement the generation by the Solomon Gulch hydroelectric project. The Solomon Gulch Project can meet all of CVEA’s current requirements during the summer, but has insufficient reservoir storage and inflow to meet requirements during the remainder of the year. The Large Project would operate primarily during the winter months and would provide power to CVEA when the existing Solomon Gulch Project reduces its output due to low reservoir levels Tos Westhegth-2 ud Ga Viaeter Oe ‘Annin 2 ener / | Mun ane ao oO - “ae 5 4 eer” i SSS & 2 /Entrance tate : = "Boint.’ * Point [SOLOMON GULCH PoweRHOUsE PE |, Lf ur A RE me fe a ; WINS wus a9 as Boh meat & ¥) FIGURE 1 SILVER LAKE HYDROELECTRIC PROJECT VICINITY MAP and insufficient storage. Both the Small and Large Projects would provide economical hydroelectric energy to energy consumers that are currently dependent upon more expensive energy or mixes of diesel and hydropower sources. SMALL PROJECT DESCRIPTION The Small Project would include the following project features, as shown in Figure 2: e An access road approximately 10 miles long from Tatitlek to Silver Lake. For the most part of its length, this road would be a single lane gravel road along the transmission line alignment. e An intake at the outlet of Silver Lake, which would allow drawing water from about 6 feet below the normal water surface. e A penstock approximately 6000 feet long, buried in the access road to the dam. The pipe would be 45-inch diameter HDPE pipe near the lake where pressures would be low, and 42-inch diameter steel pipe near the powerhouse where pressures would be higher. e A powerhouse located on the Duck River at about El 115, on a prominent bend in the river well above a series of rapids and falls that are a barrier to upstream fish migration. The powerhouse would be a reinforced concrete structure set into the ground so that the roof would be at about the existing ground surface. The powerhouse would contain two 250-kW, horizontal-shaft generating units. A small switchyard adjacent to the powerhouse would be contain a single pad-mounted transformer and recloser. e A 10-mile long 12.5-kV transmission line along the access road alignment. SLH will evaluate both overhead and underground transmission construction. LARGE PROJECT DESCRIPTION SLH is currently considering three alternative project arrangements for the Large Project configuration. Each of these alternatives has associated cost, risk, and environmental attributes, the details of which will be the subject of feasibility studies to be conducted during the Preliminary Permit period if the Large Project is pursued. The three alternatives are described in this document to generate initial public and agency comment. A preferred alternative will be selected after initial review and study, and will be presented in the Preliminary Draft Environmental Assessment and Draft License Application, scheduled to be distributed on or about October, 1998. “ACCESS ROAD AND ‘|’ | TRANSMISSION. LINE’ TOTATITLEK Hom fi wh FIGURE 24 GENERAL PROJECT ARRANGEMENT -- SMALL PROJECT All of the Large Project alternatives currently being considered would have an installed capacity of approximately 15 megawatts (mw), and would generate approximately 45 gigawatt hours (gwh) of electricity per year to meet the power needs described in the preceding section. Alternative Large Project Arrangements Each Large Project alternative would include several major features, including a storage dam, reservoir, power conduit, one or more powerhouses, access roads and transmission lines. Major differences among the alternatives at this time relate primarily to the power conduit(s) and powerhouse(s). In the following sections, we first describe the storage dam and reservoir, which are common features of all alternatives, and then the various power conduit and powerhouse configurations relative to the three alternatives, and other project features. (The names of the project features are in bold type on first reference). Storage Dam And Reservoir The storage dam and reservoir for all three Large Project alternatives would be the same design. The three alternatives currently under consideration all include a storage dam approximately 120 feet high raising the lake from El 306 to El 410. The dam would be constructed of roller compacted concrete, and would incorporate an overflow spillway. The reservoir created by the dam would have an active storage capacity of 143,000 acre- feet and would have a surface area of about 1,550 acres, 550 acres more than the existing lake. Approximately 1% miles of the valley above Silver Lake would be inundated. Power Conduit and Powerhouse Alternatives Three power conduit/powerhouse alternatives are currently under consideration. These alternatives would have different construction costs and risks, power outputs, and environmental impacts. SLH intends to evaluate all factors relative to these alternatives during the term of the Preliminary Permit. Intake/Upper Tunnel All three alternatives would include an intake at the reservoir which would divert water either through a 900-foot-long upper tunnel or across an excavated bench. SLH will evaluate the need for a multilevel intake to allow temperature control of the reservoir releases. If a tunnel were used, it would first be constructed to divert water around the damsite during construction, and subsequently would be converted for use as part of the power conduit. Power Conduit(s)/Powerhouse(s) The three alternative power conduits and powerhouses differ below the upper tunnel, and are described in the following sections: Alternative 1 Power Conduit Under Alternative 1, a 5,600-foot long lower tunnel would continue below the upper tunnel (or excavated bench) with an inclined shaft to a powerhouse on the lower reach of the Duck River (Figure 3). Among the three Alternatives, this arrangement would have the least surface disturbance (and presumably the least terrestrial and aquatic impacts), but would have a relatively large cost risk because of the amount of underground construction. Powerhouse The powerhouse for Alternative 1 (the Duck River powerhouse) would be on the Duck River about 700 feet upstream from the Lagoon (Figure 3). Alternative 2 Power Conduit The Alternative 2 power conduit below the upper tunnel would be 9,000 feet of steel pipeline and penstock (Figure 4). The pipeline would be buried in the access road as much as possible, but would include a 3,000-foot-long section on a bench cut around the hill above the lower reach of the Duck River. This alternative probably would have the least construction cost, but would involve the most construction near the important habitat of the Duck River. Powerhouse This alternative would also utilize the Duck River powerhouse in the same location as for Alternative 1. (see Figure 4). Alternative 3. Power Conduit Under this alternative, the power conduit would continue below the upper tunnel with an inclined shaft and lower tunnel 3,100 feet long to the upper powerhouse in a valley approximately midway between Silver Lake and the Lagoon (Figure 5). A regulating pond would be formed in the valley by a small dam on Reverse Creek (the Reverse Creek dam). A steel pipeline and penstock 1,000 feet long from the Reverse Creek dam would convey water from the regulating pond to the 6 “~] upPek »-~>} TUNNEL Z if) . | CK | / | LOWER EAGOON OUTFALL FSA . | AL TUNNEL | SY FIGURE 3. GENERAL PROJECT ARRANGEMENT - - ALTERNATIVE 1 Bes aa Zon =~ a: os FIGURE 4. GENERAL PROJECT ARRANGEMENT - - ALTERNATIVE 2 SILVER LAKE INTAKE = NA aN = \ - TUNNEL 000 XZ os E REGULATING POND. |f \ \ i Z The VAY - a a “| LOWER. POWERHOUSE : q ACCESS ROAD | \/ FIGURE 5. GENERAL PROJECT ARRANGEMENT - - ALTERNATIVE 3 lower powerhouse near the outfall of Reverse Creek. This alternative would probably be the most costly and would involve some risk related to tunneling. It would, however, avoid all construction near the important habitat of the Duck River and presumably would reduce terrestrial and aquatic impacts relative to the other alternatives. Also, it would have the greatest generation potential since it would develop the waters of Reverse Creek as well as those of the Duck River. Powerhouses Under Alternative 3, the upper powerhouse would be at approximately El 130 on the west bank of the regulating pond and the lower powerhouse would be at approximately El 10 on the right bank of Reverse Creek (Figure 5). For all three Large Project alternatives, the powerhouses would be prefabricated metal buildings with reinforced concrete foundations containing either two or three generating units. The building footprints would all be approximately 50 feet by 100 feet. For Alternatives 1 and 2, the total installed capacity would be approximately 15 MW. For Alternative 3, the upper and lower powerhouses would have installed capacities of approximately 10 MW and 5 MW respectively. The turbines would be horizontal shaft Francis units direct-connected to horizontal shaft generators. Other equipment contained in the powerhouse would include inlet valves, tailrace gates, a bridge crane, a generation control system, miscellaneous plant mechanical and electrical systems and a blowoff valve. Switchyard A switchyard would be located adjacent to the powerhouse(s). The switchyard would include the main transformers, circuit breakers and switches. Instream Flow Release Facilities All three Large Project alternatives would include facilities for releasing water into the Duck River to maintain instream flows. Upstream salmon migration in the Duck River is blocked by a barrier falls approximately 3,500 feet upstream of the mouth. To provide instream flows to this stream reach under alternatives 1 and 2, a buried instream release pipe would be constructed from the powerhouse to a point on the Duck River upstream of the salmon habitat. Some of the water discharged from the powerhouse would travel up the pipe under pressure, and be released at a point above the salmon migration barrier. Under Alternatives 1 and 2, the powerhouse would discharge high flows during the winter when the natural flows are low. To minimize the potential impact of these high flows on the Duck River and intertidal salmon spawning area near its mouth, SLH will evaluate the feasibility of a tailrace pipeline from the powerhouse to a lagoon outfall in the Lagoon. This arrangement would allow SLH to selectively release water from the powerhouse 12 either into the instream flow release pipe or into the Lagoon outfall, as determined by results of instream flow studies. Under Alternative 3, instream flows would be released from the regulating pond to the Duck River above the barrier falls. Under this alternative, high flows in the winter would be released from the powerhouse no. 2 into Reverse Creek, thus avoiding high flow impacts in the Duck River. Transmission Line SLH is currently evaluating three potential transmission line routes to the Valdez service area and another route to the Tatitlek area (Figure 6). Each of the routes to Valdez would terminate at the existing Solomon gulch project switchyard in Valdez. The Valdez routes are: 1). A submarine cable through Galena Bay, Valdez Narrows and Port Valdez (a distance of approximately 28 miles); 2). A tidewater overhead transmission route near along Galena Bay and Port Valdez (a distance of approximately 26 miles, including a one-mile long underwater crossing of Jack Bay); and 3). An overland transmission route crossing the two mountain ridges between Silver Lake and Valdez (a distance of 22 miles). Each of these transmission line alternatives have different levels of reliability, construction costs, and environmental impacts, which will be evaluated before a preferred alignment can be selected. In addition, SLH will evaluate the feasibility of a Tatitlek transmission line from the project to that community, a distance of approximately 10 miles. Access Roads Currently, access to the Project area is only by boat or by air. During construction and operation, SLH would construct a boat dock and barge unloading facility at the head of Galena Bay near the outlet of the Lagoon. Relative to the three Project Alternatives, there are currently two access road arrangements. For Alternatives 1 and 2, a single lane, all- weather dam/intake access road approximately 4.5 miles long would be constructed from the boat dock to the dam/intake site. A Duck River powerhouse access road approximately 0.5 to 1.0 miles long would be constructed to provide access to the powerhouse (see Figures 2 and 3). Alternative 3 would utilize the same 4.5 mile intake access road, which, under this Alternative, would also provide access to the upper powerhouse (see Figure 4). The lower powerhouse would be accessed via an approximately 0.5 mile lower powerhouse access road. 13 Anderson PY +t SOLOMON GULCH POWERHOUSE [<7 < PN ee Bee einer NAN FIGURE 6 SILVER LAKE HYDROELECTRIC PROJECT ALTERNATIVE TRANSMISSION LINE ROUTES PROJECT OPERATION The project operation would be dictated by the variability of the load to be served and the flow rate required for the instream flow releases. The instream flow rate during the summer months would have a major influence on the feasibility of the project. The project alternatives would all allow generation with the instream flow requirement, but, during the summer, there would be very limited need for the generation since the existing Solomon Gulch project can currently meet most of Valdez’s summertime requirements. If the project studies indicate that a relatively high instream flow rate is necessary during the summer, SLH will evaluate the feasibility of modifying the operation of Alternative 3 so that a portion of the instream flow requirement is pumped from the Lagoon into the regulating pond and then released back to the Duck River. This operation would both decrease the amount of discharge required from the reservoir and provide a load to be met by the reservoir releases. SLH has developed Duck River streamflow data by correlation of the existing Duck River flow data to the long-term flow records of Power Creek near Cordova. SLH has used that correlated data to develop preliminary pre- and with-Project hydrographs (Appendix 1). In the Appendix, we describe the various conditions represented by the hydrographs. Please note that these hydrographs have been constructed using preliminary streamflow and load data. LANDS OWNERSHIP In general, most of the project, with the exception of the proposed facilities near the city of Valdez, lies on lands of the Chugach National Forest (Forest). Within these forest lands, however, much of the proposed project area lies on lands patented from the Forest to the Chugach Alaska Regional Native Corporation (Chugach Corporation). The main project features near Silver Lake (dam/intake, power conduits, powerhouses, switchyards, docks and access roads) are either on Chugach Corporation lands or on lands patented to the Tatitlek Village Corporation (Tatitlek Corporation). Much of the land crossed by the proposed overland transmission line route is managed directly by Forest. Lands crossed by the proposed Tatitlek transmission line are variously owned or managed by the Forest, Chugach Corporation, or the Tatitlek Corporation. Ownership of project-affected lands near the city of Valdez and Tatitlek is complex. In these areas, there are numerous private holdings and parcels patented to individuals, industries, the City of Valdez and the Tatitlek Corporation. SLH will conduct detailed land-ownership surveys for these areas depending upon which Project and Transmission line Alternatives are selected. 15 MARKET FOR POWER GENERATED Small Project The proposed market for the power from the small project is the community of Tatitlek. These villages are currently supplied by diesel generators with a combined installed capacity of 425 kW. The proposed small project would replace this diesel generation entirely. The cost of power from the small project would depend a great deal on the amount of federal or state contribution. Large Project The proposed market for the power from the large project is comprised of three potential components: 1) the Tatitlek load as described above, 2) the Copper Valley Electric Association, Inc. which serves Valdez, Glennallen and its contiguous areas, and 3) the Petro Star refinery in Valdez. Presently, CVEA power is supplied in the summer by the Solomon Gulch Hydroelectric Plant in Valdez, and, in the winter, by the Solomon Gulch Hydroelectric Plant and by diesel power plants in Glennallen and Valdez. SLH expects to replace the present diesel generation with the output of the large project. SLH will also investigate the potential for supplying power directly to the Petro Star refinery, which would provide a summer market for the potential power produced by the project instream flow releases. ENVIRONMENTAL RESOURCES AND ISSUES In the following sections we describe the environmental resources potentially affected by the Project. Our current state of knowledge of these resources and issues is based on existing information. SLH will conduct formal study planning after receiving comment on this document and subsequent public meetings, and will develop plans for studies, some of which may involve field surveys. In all further sections concerning environmental resources, the text references resources potentially affected by the Large Project proposal, with an overland transmission line to Tatitlek, or the combination of features with the most extensive potential for environmental effect. AFFECTED ENVIRONMENT Information Sources and Previous Studies Information on resources and issues in this document is derived from previously- conducted studies and surveys, which include the following: 1) In 1980-1981 United States Army Corps of Engineers (COE) conducted a power assessment of Silver Lake. (United States Army Corps of Engineers, 1981). 16 2) A study was completed by R. W. Rutherford Associates for the Alaska Power Authority (APA) and the City of Cordova. (R. W. Rutherford Associates, 1981). In this study, Silver Lake was identified as one of the alternative small hydroelectric sites. The study presented load forecasts and a preliminary feasibility evaluation. 3) In 1981-1982 Stone & Webster Engineering Corporation, under contract to APA prepared, an assessment of the Silver Lake project and area (Stone and Webster Engineering, 1982). This study involved the following: e Agency coordination and public participation e Electric energy forecasts e Preliminary hydroelectric conceptual design and analysis e Intertie conceptual design and analysis e Preliminary environmental analysis e Hydrologic investigation e Air quality and meteorological tests e Cost estimates e Socio-economic investigations 4) In 1982 Dowl Engineering Corp., under contract to Stone and Webster Engineering Corp., conducted environmental and geologic field investigations in the project area (Stone and Webster, 1983). The report addressed a broad variety of resource and contained extensive data collection results on: e Stream gaging stations at the mouth of Silver Lake and the mouth of the Duck River above tide water. e Surface and ground water temperature and water quality recording stations. e Topographic mapping and survey. e Water quality studies of the lake, stream and lagoon. e Avian and terrestrial species in the project area and the extent of utilization of the area by the species. e Mapping and classification of vegetation and wildlife habitat in the project area. e A fisheries field program related primarily to anadromous fish in the lower Duck River and the Lagoon coordinated with the Alaska Department of Fish and Game in anticipation of future instream flow assessment. e A sampling program for invertebrates (both fresh water and intertidal) in Silver Lake, the Duck River, the Lagoon and Galena Bay. 17 e An inventory of recreation and subsistence use of the resources within the project area. e A reconnaissance level survey of cultural, historical and archaeological resources within the project area. e A geological and geotechnical survey that included regional geologic mapping, site-specific geology (including soil series), core drilling, identification of geologic hazards and an assessment of available construction materials. Following is a summary of existing environmental resources in the project area. The information is preliminary and subject to revision based on additional information and studies conducted by SLH. _ Readers are encouraged to provide additional information or sources of information on these resources in written or oral comments. Aquatic Resources Silver Lake. A fish survey conducted by ADF&G in 1972 produced only Dolly Varden and sculpin from Silver Lake. Indications from the survey were that there was only light fishing pressure at the outlet area by Valdez area sport fishers. Dowl Engineers (1983a) surveyed Silver Lake and its tributaries in 1982 and found only Dolly Varden and sculpin. Duck River. The Duck River is listed in ADF&G anadromous fish Catalogue (ADF&G, 1993a and b) as offering habitat for both pink and chum salmon from tidewater to the barrier falls approximately 3,500 ft. upstream. Duck River is one of the more productive salmon streams in Prince William Sound. Phil Sharp of ADF&G, in a recent communication within that agency, described the Duck River as the most important pink salmon spawning area in eastern district of Prince William Sound. Duck River averages between 4% and 6% of the entire Prince William Sound escapement for pink and chum salmon respectively. The Duck River is an aerial index area, meaning that ADF&G counts fish in the area from aircraft on a weekly basis during the migration and spawning seasons. These aerial index results have been collected by ADF&G from 1960 to the present. From 1960 to 1996, the estimated pink salmon escapement averaged 51,000 and ranged from a high of 124, 000 in 1976, to a low-of 7,000 in 1965. During that same time period, chum salmon escapement averaged 13,000 with a high of 30,000 in 1973 and a low of 2,000 in 1975 and 1979. Over the period of observation, pink salmon index counts have remained stable or risen slightly in recent years while chum salmon counts have decreased in the past five years. Silver salmon are also present in Duck River but the abundance is unknown and estimated to be low. Dowl Engineers (1983a) studied the Duck River and the Lagoon and found the areas most utilized by both pink and chum salmon. They also reported on the periodicity of pink and 18 chum salmon life history phases including spawning, incubation, rearing, outmigration and inmigration. Salmon spawning in the Duck River/Lagoon area occurs intertidally and in the lower reaches of the Duck River. The river flows through a rock gorge from Silver Lake to about 2 mile above mean low water. It is believed that this gorge forms a velocity barrier for fish passage. Downstream of this barrier, Duck River has a more moderate gradient and smaller and more suitable substrate size. Elsewhere in the Project area, the Alaska anadromous fish Catalogue (ADF&G 1993 a and b) lists anadromous fish only in Millard Creek which empties into Galena Bay. No anadromous fish are listed for Reverse Creek. The Lagoon/Galena Bay. The Lagoon was studied in detail in 1982-83 by Alaska Biological Consultants (1983). They found several species of typical intertidal organisms in the Lagoon, both free-living and in the substrate. The intertidal community was described having lower diversity than usual, perhaps because of the amount of fresh water from the various stream inputs. The researchers found no organisms which would be on the Threatened or Endangered species lists today, but the study was conducted long enough ago that it may not represent the current list of organisms in the Lagoon. The authors cautioned against project operations which might alter the salinity and temperature regimes in the lagoon. Pacific herring spawn along the north shore of Galena Bay near Valdez Arm. The project area also supports shellfish populations throughout Valdez Arm, Port Valdez and Galena Bay. Terrestrial Resources The area surrounding Silver Lake has a good population of mountain goats, with 291 goats counted on a 1981 ADF&G survey between Jack Bay and Port Fidalgo. Silver Lake is one of the most popular goat hunting areas in Prince William Sound, and in 1980 sustained the fourth highest harvest in the area (10 animals, 5 males and 5 females). The area is subject to periodic aerial surveys conducted by ADF&G which indicate use of the area as winter and summer habitat and for kidding. Recent ADF&G surveys indicate that goat populations in the area have declined in the past 20 years (Nowlin, 1996, Hicks, 1994, Abbot, 1992). These reports generally show a population of goats in the Game Management subunit which contains Silver Lake, to range from 100 to 200 goats, relative to an estimated 3,000 goats in all of Game Management Unit 6, which extends includes all of Prince William Sound and the Alaska coast to as far south as Cape Yakataga. Black bear habitat is good to excellent in this portion of Prince William Sound and the Duck River-Silver Lake area has a good population of black bears. Black bear utilize the slopes behind the lake for spring feeding on vegetation and feed along the lower slopes of Duck River when salmon are present (Stone and Webster, 1983). 19 Brown bears are uncommon in the Silver Lake area, although recent ADF&G reports (Nowlin, 1994) indicate that brown bear populations in the Game Management subunit containing Silver Lake are “moderate”. No brown bears were noted in the 1982 environmental surveys by Dowl Engineers in the Project area (Stone and Webster, 1983). Although sitka black-tailed deer are common in Prince William Sound and areas further south, they tend to be most abundant on the islands and not on the mainland. No deer were noted in the studies reported in Stone and Webster, 1983. Moose are not present in this area of Prince William Sound. At least one family of river otters is using Duck River (spring observation ’82). Limited use of the shallow lagoon is made by marine mammals, principally by sea otters, and there are established populations of sea otters throughout the nearshore areas of Valdez Arm, Port Valdez, and Galena Bay. Stone and Webster (1983) provided an extensive list of birds in the Project area. According to recent communications from ADF&G, information on birds in the Project area is not complete. In their letter to SLH dated October 20, 1995, ADF&G stated that a small Arctic tern colony is located on the east shore of Valdez Arm at the entrance to Galena Bay. Ducks and geese are thought to be generally distributed throughout the area, but specific information on nesting, molting and staging areas is not available. Bald eagle nesting has been documented around Galena Bay and The Lagoon. Water Use and Quality The Duck River does not currently have a streamflow gage installed, nor is there a monitoring device at Silver Lake. Dowl Engineering Corp. (1983) reported on approximately 5 months of stream gaging and lake level measurements, but did not establish long-term monitoring stations on either the Duck River or Silver Lake. The streamflow measurements were made by Dowl Engineers were used in a synthesis of Duck River streamflow using data from Power Creek, near Cordova, Alaska, (Dowl Engineers 1983), (Figure 6). Low flows, present from mid-December through mid-April of most years, range from 50 to 100 cubic feet per second (cfs). During April and May flows increase due to snowmelt and increased rainfall, and reach monthly averages greater than 650 cfs throughout June, July and August, falling again in September as precipitation slows and temperature declines. Other than the studies performed by Dowl Engineers in 1982, there have been no formal studies of water quality in either the Duck River or in Silver Lake. The Dowl studies showed the water quality in the Duck River to be good, as would be expected for a stream in an uninhabited area with no industrial, residential or other pollution sources. Geology and Soils Geologic data in the Project area are extensive. Dowl Engineers (1982, draft report) developed detailed soil series for the entire project area including the areas around Silver 20 Lake. Subsurface geology was studied by Dowl Engineers in 1982 as part of the geotechnical feasibility studies for that project. Four drill-logs are available in the Dowl report from the areas which would be utilized by the SLH project alternative designs. Recreation No formal recreation surveys have been conducted in the area. The ADF&G fisheries studies at Silver Lake conducted in 1972 indicated that there was light use of Silver Lake by sport fishers from the Valdez and perhaps Anchorage areas. There is known to be some float plane traffic in and out of Silver Lake, but the usage has not been quantified. As mentioned in the terrestrial resources section, the slopes above Silver Lake are used for hunting of mountain goats and black bears, and the area is one of the more popular areas for hunting these species in Prince William Sound, perhaps because of the proximity to Valdez and the relative abundance of these game species in the area. In the summer of 1996, the US Forest Service Cordova Ranger District developed a foot- trail from the lagoon area to Silver Lake and beyond for access through Village and Native Corporation lands to the Chugach National Forest Lands east of Silver Lake. This trail substantially increases recreational access within the Project area, relative to the situation prior to its construction. Cultural Resources The Dowl Engineers studies (Dow! Engineers, 1983) found two potential cultural resources sites near the damsite/intake location. No other cultural or historic sites are known to exist in the project area. Visual/Aesthetic Resources The area surrounding Silver Lake and the Lagoon is currently undisturbed and offers very high-value visual resources. No current data is available which quantify these resources, but the US Forest Service has offered the highest possible level of protection for the recreational, scenic and aesthetic resources of the areas they manage in their most recent Forest Plan. EXPECTED RESOURCE ISSUES, PROJECT EFFECTS AND MITIGATION Aquatic Resources The primary Project effects would result from changes in streamflow and effects on fish (particularly pink and chum salmon) spawning habitat in the Duck River, its delta and The Lagoon. SLH will consult with fish and wildlife agencies to develop and conduct studies to quantify effects of various alternative flow regimes on instream habitat and to optimize 21 project operation relative to these effects. Mitigation would generally be in the form of flow regime changes to minimize habitat losses. In certain cases, fisheries mitigation may be in the form of off- or on-site habitat improvements for the affected or other relevant resources. Water Use and Quality Water use effects would be those on existing uses and quantities of water in the Duck River, Silver Lake and other affected waterways. The project operation would have to comply with existing Alaska state water allocation priorities, including instream flow and lake level requirements from ADNR and ADF&G. Water quality could be affected during construction through excavation, fill, spoils disposal and road and water conduit route construction. During long-term operation, water quality, including temperature in Silver Lake and the Lagoon and sediment concentrations in the Duck River, could be affected by reservoir operation and instream flow. SLH would develop, through consultation with resource agencies, an Erosion and Sediment Control Plan (ESCP) which would specify both construction and long-term practices to minimize effects of erosion and sedimentation. Terrestrial Resources Wildlife or vegetation effects would relate to 1.) construction activities, including noise associated with blasting and equipment operation, human activity and encounters and 2.) long-term existence and operation of the project, including habitat losses due to land clearing and inundation and effects on migration and feeding routes. After study review and agency consultation, construction practices would be proposed to minimize wildlife disturbance. Project facilities locations would be evaluated with respect to wildlife habitat and may be changed or redesigned to minimize impacts. The Project, particularly inundation related to a rise in Silver Lake elevation, would affect certain areas which might be classified as wetlands. SLH would consult with the appropriate agencies to determine which areas exist and measures which might mitigate for wetland losses. Cultural Resources Cultural resource impacts are not expected to be great. The 1982-1983 studies conducted by Dowl Engineers indicated that there were two potential cultural resource sites near the dam site. No formal surveys for cultural resources have been conducted near the other proposed project features such as access roads, transmissions lines, powerhouses or impoundments. The primary method to address cultural impacts would be avoidance, if possible. For any significant cultural or archaeological features encountered which could not be avoided, SLH would consult ADNR to determine appropriate methods of retrieving or otherwise protecting artifacts or sites. 22 Recreation Recreation in project area could be affected by both construction and long-term operation of the project. Certain access restrictions might be placed on construction zones for safety purposes. The access roads might facilitate public accessibility to areas which are currently quite primitive because of access difficulty. Presence of project features might reduce the recreation experience on or near Silver Lake, as might the rise in reservoir elevation and inundation of shoreline wetlands areas. Visual/Aesthetics Resources The presence of the project features, depending on which alternative is selected, might have moderate impacts on the visual quality of the project area. Geology and Soils Resources Most project-related effects for these resources would be on soils which might be disturbed due to project construction. Soil effects would be addressed in part through the ESCP and its associated construction practice directives, and in part through project design which would avoid sensitive or unstable soils areas. ENVIRONMENTAL STUDIES SLH intends to conduct studies relative to several resources to determine the engineering, economic and environmental feasibility of the project. The FERC regulations require that State and Federal resource agencies be consulted prior to conducting environmental studies. Further input on studies may result from comments received on this document and the various other documents and public meetings required prior to licensing. Following are general descriptions of studies which might be conducted in the various resource areas, but do not represent formal proposals for study: Aquatic Resources Aquatic resources are typically studied through research of existing literature and, when necessary, by field surveys of the fish, invertebrates and vegetation of the lakes and streams potentially affected by the project. Generally, SLH will utilize the survey results from the 1982-83 work done by Dowl Engineers and any more recent survey results which may have been conducted by Alaska Department of Fish and Game (ADF&G), including aerial fish escapement surveys and/or foot surveys. Other study results may be obtained from surveys conducted after the Exxon Valdez oil spill. Based on input from the resource agencies, SLH will decide whether to conduct further field studies of fisheries in the Duck River, its tributaries, the Lagoon and in Silver Lake. 23 Another important aquatic resources issue could be instream flow, or the effects of changes in the streamflow regime in the Duck River as a result of project storage and release operations. Instream flow studies to quantify the effects of streamflow changes on aquatic life may be done using only existing or synthesized streamflow records, or through more sophisticated techniques which require intensive measurement of hydraulic and habitat features. SLH will decide, based on input from natural resource agencies, which instream flow technique(s) would be employed. Terrestrial Resources Terrestrial resources (typically categorized as either 1) wildlife or 2) botanical resources) are typically studied through review of existing literature and, if necessary, by field surveys of the plants and animals in the potentially-affected area. Wildlife resources may be studied in the field using aerial survey techniques and ground surveys which might include large and small mammals and birds. A survey for various rare, threatened and endangered species is often conducted if responsible agencies believe that they might occur in the project area. Botanical resources studies involve describing and classifying the vegetation in the project area, determining the presence of sensitive, rare, threatened or endangered plants, and determining the value of the potentially-affected vegetation as habitat for wildlife. In addition, SLH might be asked to conduct a determination of the occurrence of wetlands which might be affected by project construction or long-term operation. Cultural Resources Cultural Resources include prehistoric and historic artifacts in the affected area. Alaskan cultural resources usually include evidence of use by native American peoples and recognition of locations which might be important to those peoples. SLH will consult with the ADNR State Historic Preservation Officer (SHPO) and, based on that initial consultation, determine whether field surveys are necessary. If cultural resources studies are necessary they are typically done by a qualified cultural resources specialist using foot surveys and mapping techniques in the potentially affected areas. After a reconnaissance level survey, the SHPO may determine that more detailed surveys and mapping might be required. All survey reports would be reviewed by the SHPO who would make final recommendations regarding the significance of sites or artifacts found. Recreation Resources Recreation resources are often studied using literature review and, if found necessary during consultation, field surveys. Such field surveys involve stationing survey personnel at specific trailheads or known recreation areas. The surveyors may either distribute questionnaires or ask questions in addition to counting the numbers of people who pass the survey site or are seen in a pre-determined area. The recreational use of the Silver 24 Lake area appears to be light and SLH initially proposes to use existing data to characterize the type and level of use. Visual/Aesthetic Resources These resources are often studied using renderings of the project features both before and after the project is constructed. SLH, in the course of its engineering design for the project, will develop drawings of the project features, both in the pre- and the with-project conditions. Mitigation for aesthetic impacts is facilitated by use of computer-based depictions of various alternative ways of building, shaping and painting various project features. Geology and Soils Resources These resources include the surface features of both rock and soil in the project area, with interest in slope and structural stability, permeability, and the subsurface features which might affect structural stability, resistivity, and earthquake potential. These resources are typically studied by initial literature survey, and field work, including soils surveys and rock analysis. SLH will examine all previous studies on the Silver Lake Project area, including seismic work and the avalanche/slide potential in this area. We will examine the intake structure site, ground storage sites, building locations and power plant site. We do not currently plan to conduct drilling at the damsite. Instead, we will utilize the bore logs from the 1982- 83 studies conducted by Stone and Webster for the Alaska Power Authority. If information from those bore logs proves insufficient, we will inform the FERC and relevant Alaska agencies and land owners of our intention to conduct drilling and will provide maps of the proposed drilling sites. Drilling will be necessary in the area(s) of all tunnels, as they may relate to the selected Alternative. Water Use and Quality In this area, the important factors are 1.) water use (how water in the project area is currently allocated and how much water might be needed to serve the project purposes) and 2.) water quality (the quality or the water in potentially affected streams and lakes and how it might be changed by project construction and operation). Water quantity and quality studies are typically done using existing records, if available, or through installation of stream gages and water quality measuring instruments. Based on consultation with Alaska state and federal agencies, SLH will conduct studies to document existing water use and quality and to aid in predicting project-related effects on those resources. 25 ENGINEERING STUDIES SLH will conduct engineering studies to evaluate the various project alternatives and select the most appropriate one to propose in the application for FERC license. The selection will consider environmental concerns as well as technical and economic criteria. The engineering studies will utilize and build upon the results of the previous studies of the project area as described previously. The engineering studies will include the following: Field Reconnaissance: SLH will conduct on-site examination of the locations of the various project features to obtain an understanding of the geotechnical, topographic, and vegetal conditions. Topographic Mapping: SLH has acquired detailed topographic mapping of the Silver Lake area developed in the early 1980’s. SLH will either convert that mapping to a digital format or will obtain new digital mapping to allow use in CAD development of the project preliminary designs. Geotechnical Explorations: SLH will conduct geotechnical explorations of the most promising power conduit arrangement. Sufficient explorations have already been conducted at the Silver Lake outlet to confirm the viability of a storage dam. Explorations for the power conduit may include mapping, seismic refraction surveys, and core boring. Hydrology Studies: SLH will review existing streamflow correlations and modify them as appropriate to develop a long-term daily streamflow data set. SLH will also develop a peak flow data set for use in sizing flood-dependent project features. Load Studies: SLH will obtain recent hourly or daily load data for the potential power markets to use in the operations studies and in selecting the final installed capacity. Operation Studies: SLH will refine its existing computer model of the Silver Lake Project to exactly model the proposed daily operation and to optimize the sizing of the project features. Alternative Arrangements: SLH will evaluate various sizes and layouts of the various project features and alternatives based on geotechnical, hydraulic, power output, and economic criteria to determine the most beneficial and cost-effective arrangement. Estimation of the construction and operating costs and benefits is inherent in this evaluation. 26 LICENSING SCHEDULE Following is the proposed licensing schedule for the project. This schedule is preliminary and subject to change as a result of study results and consultation and review timing. Event Approximate Timing Initial Consultation July, 1997 Environmental Study Planning July-October, 1997 1997 Field Studies August-October, 1997, continued, as required Scoping October-November, 1997 Draft License Application Submittal February, 1998 Draft License Application Review February-May, 1998 Continued Field Studies April-October, 1998 Final License Application November, 1998 FERC Draft Environmental Assessment March, 1999 Final EA and License Order September, 1999 27 REFERENCES Abbot, Susan M. (Ed.) (Report prepared by Roy Nowlin), 1992. Mountain Goat. Federal Aid in Wildlife Restoration, Survey Inventory Management Report, 1 July-30 June, 1991. ADF&G Division of Wildlife Conservation, Anchorage, AK. Alaska Biological Consultants, 1983. Benthic Ecology of the Duck River Lagoon and Proposed Galena Bay Dock Site. Prepared for Dowl Engineers, Anchorage, AK 63 pp. ADF&G. 1993a. Catalog of Waters Specified as Important for the Spawning, Rearing, or Migration of Anadromous Fishes. ADF&G Habitat and Restoration Division, Anchorage, AK. ADF&G. 1993b. Atlas to the Catalog of Waters Specified as Important for the Spawning, Rearing or Migration of Anadromous Fishes. ADF&G Habitat and Restoration Division, Anchorage AK. Dowl Engineers, undated (assumed to be 1983). Draft Geology and Geotechnics of the Proposed Silver Lake Hydropower Project. Prepared for Stone and Webster Engineering and Alaska Power Authority, Anchorage Alaska. 112 pp. Plus Appendices. Dowl Engineers, 1983. Draft Environmental Field “Study Plan” (1983-84), Silver Lake Alternative, Cordova Power Supply Feasibility Analysis, Phase II. Prepared for Alaska Power Authority, Anchorage AK, 44 pp. plus figures. Hicks, Mary V. (Ed.) (Report prepared by Roy Nowlin), 1994. Mountain Goat, Federal Aid in Wildlife Restoration Survey-Inventory Management Report, | July-30 June, 1993. ADF&G Division of Wildlife Conservation, Anchorage, AK. Nowlin Roy, 1994(?). Untitled. Draft report on brown bear surveys in ADF&G Game Management Unit 6, 1992-1994. ADF&G Division of Wildlife Management Conservation, Anchorage AK. Nowlin, Roy, 1995(?). Untitled. Draft report on mountain goat surveys in ADF&G Game Management Unit 6, 1993-1995. ADF&G Division of Wildlife Conservation, Anchorage, AK. Stone and Webster Engineering Corp., 1982. Cordova Power Supply, Interim Feasibility Assessment, Volumes 1 and 2. Report prepared for the Alaska Power Authority, Anchorage, AK. Stone and Webster Engineering Corp., 1983. Cordova Power Supply, Silver Lake Hydroelectric Site, Field Data Collection, Apr-Oct 1982. Report prepared by Dowl Engineering Corp. for the Alaska Power Authority, Anchorage, AK. United States Army Corps of Engineers, Alaska District, 1981. Electrical Power for Valdez and the Copper River Basin. Interim Feasibility Report and Final Environmental Impact Statement. 28 United States Department of the Interior Forest Service, 1972. Review Report, Powersite Withdrawal, Duck River, Silver Lake, Near Valdez, Alaska. 29