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HomeMy WebLinkAboutCathedral Falls Project, A Reconnaissance Report 1979CIIPf /JbV -~ 001 October 1979 CITHIDRIL FILLS PRDJICT A Reconnaissance Report ALASKA POWER AUTHORITY LIBRARY COPY PLEASE DO NOT REMOVE FROM OFFICE~ , STATE OF ALASKA ALASKA POVVER AUTHORITY Anchorage, Alaska By HARZA Engineering Company Chicago, Illinois ... - - .... ... CATHEDRAL FALLS PROJECT A Reconnaissance Report Prepared for the State of Alaska Alaska Power Authority Anchorage, Alaska by Harza Engineering Company Chicago, Illinois October, 1979 .... ... ... .. , .. ~ ENGINEERING COMPANY CONSULTING ENGINEERS Alaska Power Authority Suite 31 333 West 4th Avenue, Anchorage, Alaska 99501 Attention: Subject: Gentlemen: Mr. Eric P. Yould Executive Director Cathedral Falls Project Summary Letter October 18, 1979 We present the results of our reconnaissance study of the Cathedral Falls Project. The study includes technical, eco- nomic and environmental evaluations of the Project. We recommend that a feasibility study leading to an FERC license application be made of the Project, if financing at an interest rate equal to or less than 5 percent can be obtained and if a reconnaissance study of wood-fired electricity generation and the availablility of wood fuel resources does not show that type of project to be more attractive than the Cathedral Falls Project. The following paragraphs briefly describe the Project and the studies which were made. The Cathedral Falls Project The Cathedral Falls Project is located at the falls, on the creek of the same name, about 10 miles southeast of the town of Kake on Kupreanof Island in Southeast Alaska. The Project would have an installed capacity of 750 kW and, at full produc- tion level, would produce about 3,680 MWh in an average year. The Table of Significant Data at the end of this letter con- tains pertinent data on the Project. A plan and sections of the Project are shown on Exhibits C-2 and C-3 of the report. The Project will consist of a dam, spillway, intake, penstock, powerstation and transmission line. The dam will be a low 150 SOUTH WACKER DRIVE CHICAGO, ILLINOIS 606oS TEL. (312) 855-7000 CABLE: HARZENG CHICAGO TELEX 25-3540 ... ' ... ... '. ... - ,"" Alaska Power Authority October 18, 1979 Page Two concrete gravity structure containing an uncontrolled spillway. Maximum dam height will be about 27 feet. Water will pass through a 6.5 foot diameter steel penstock 470 feet long. The penstock will pass through a 9.0 foot diameter tunnel for 360 feet of its length. A powerstation will be constructed near the base of the falls. The powerhouse will be a prefabricated metal building containing two vertical shaft, fixed blade propeller turbines. Each turbine will be directly coupled to a generator rated at 375 kW. Power from the Project will be transmitted to Kake over a 9-mile long, 12.5-kV transmission 1 ine. Identification of the potential environmental impacts of the Project shows that there do not appear to be any adverse environmental impacts of a magnitude which would preclude project development. Anadromous fish spawn below the falls, but construction and operating procedures can be adopted to reduce this impact. Costs The construction cost of the Project includes the direct cost of civil works, contractor's overhead and profit, purchase and installation of equipment, contingencies, engineering and owner's administration, but excludes price escalation beyond the date of the estimate and interest during construction. The estimated construction cost of the Project, at September, 1979 price level is $7.1 million. Operation and maintenance cost for the Project is estimated at $40,000 per year at September, 1979 price level. Economics A comparison of benefits produced by the Project, as measured by the cost of alternative diesel generation, with the cost of the Project shows that the Project has a benefit-cost ratio of about one at an interest rate of 5 percent, assuming a differ- ential fuel cost escalation of 2 percent. · .. '" ... .. ... .. ... .. ' .. .. .... .... .... Alaska Power Authority October 18, 1979 Page Three The average cost of energy over the 50-year life of the Pro- ject, at September, 1979, price level, would be 20.8 cents/kWh for the Project. This compares with 24.3 cents/kWh for the diesel alternative. Schedule The Project could enter service by the beginning of 1984, if an organization framework is developed, financial feasibility is established, and feasibility studies are started in the fourth quarter of 1979. Conclusion We find the Cathedral Falls Project to be attractive if financ- ing can be obtained at an interest rate of 5 percent or less • We recommend that financing alternatives be investigated as soon as possible. Concurrently, a reconnaissance level study should be made of the use of wood as a fuel to supply Rake. The study should include an evaluation of both direct combustion and biomass conversion. Also, a brief reconnaissance level study should be made of an interconnection to Petersburg. A decision can then be made whether to implement the Cathedral Falls Project, based on the availability of suitable financing and viable alternative projects • We would be pleased to provide you any assistance you may require in these matters. Very truly yours, Arthur E. Allen Project Director ... "II .. .. ... ... TABLE OF SIGNIFICANT DATA RESERVOIR Water Surface Elevation, ft msl Normal Maximum Minimum Tailwater Elevation, ft msl Surface Area at Normal Max. El.,ac Estimated Useable Storage, ac-ft Type of Regulation HYDROLOGY DAM Drainage Area, sq mi Avg. Annual Runoff, cfs/mi 2 Streamflow, cfs Maximum Monthly Average Annual Mi nimum Monthly Type Height, ft Top Elevation, ft msl Dam Volume, cy SPILLWAY Type Crest Elevation, ft msl Width, ft Design Discharge, cfs TUNNEL Diameter, ft Length, ft PENSTOCK Type Diameter, ft Length, ft Shell Thickness, in 115 110 26 6.5 30 None 27.2 3.8 180 103 38.3 Conc. Gravity 27 125 13,000 Conc Ogee 115 70 8600 9 360 Steel 6.5 470 0.25 ... ... .. TABLE OF SIGNIFICANT DATA (Cont'd) POiJERSTATION Number of Units (Initial) Turbine Type Rated Net Head, ft Generator Unit Rating, kW Full Load Discharge, one unit, cfs POWER AND ENERGY Installed Capacity, kW Firm Capacity, kW Avg. Annual Energy Genera tion,MI.vh Avg. Plant Factor, % COSTS AND ECONOMICS Construction Cost, $xl0 6 Unit Cost, $/kW inst B/C Ratio @5% with 2% fuel escalation Average Cost of Energy, cents/kWh 2 Propeller 84 375 62 750 120 3450 53 7.1 9470 1/ 0.94=- 20.8 !! Without cold storage (1.04 with cold storage). .11 ,,' .. .,. .", CATHEDRAL FALLS DETAILED TABLE OF CONTENTS - C Chapter I. II. Summary Letter Table of Significant Data Table of Contents Foreword Purpose and Scope Background and Previous Studies Authorization Acknowledgements Project Setting Location and Access Population and Economy Electric Power System Utilities Existing Facilities Power Market Forecast Topography Geology Hydrology Ecology The Cathedral Falls Project General Description I ntroduc tion Project Arrangement Project Functional Design Hydroelectric Power Production Geology, Foundations and Construction Materials Description of Project Facilities Dam and Spillway Power Intake Penstock and Power Tunnel -i- -i- C-F-l C-F-l C-F-l C-F-2 C-F-2 C-I-l C-I-l C-I-l C-I-l C-I-l C-I...,l C-I-2 C-I-3 C-I-3 C-I-3 C-I-4 C-II-l C-II-l C-II-l C-II-l C-II-2 C-II-2 C-II-2 C-II-4 C-II-4 C-II-5 C-II-5 .. ... ... DETAILED TABLE OF CONTENTS (Cont'd) Powerplant Switchyard and Transmission Access Roads Reservoir Spoil Disposal Envirorunental Aspects Project Constuction First Year Second Year Proj ect Costs Cons truc t ion Operation and Maintenance III. Project Selection and Operation Stream Regulation Characteristics Type, Number and Capacity of Generating Units Power and Energy Production IV. Economic Analysis ~ Methodology V. ," Alternative Sources of Power Wind and Solar Load Management and Energy Conservation Interconnection Other Hydro Wood Diesel Economic Criteria Economic Comparison Cost of Energy Recommendations and Implementation Recomme nda t ions Organizational Framework and Financing Pre-Construction Activities Implementation Schedule -ii- C-II-6 C-II-7 C-II-7 C-II-8 C-II-8 C-II-8 C-II-9 C-II-9 C-II-ll C-II-ll C-II-ll C-II-l3 C-III-l C-III-l C-III-l C-III-3 C-IV-l C-IV-l C-IV-l C-IV-l C-IV-2 C-IV-2 C-IV-3 c-rV-5 C-IV-6 C-IV-7 C-IV-7 C-IV-8 C-V-l C-V-l C-V-l C-V-2 C-V-3 ,,' ,,. .. .. '. ,oM C-l C-2 C-3 C-4 C-S C-6 C-7 A B C D EXHIBITS General Location Map General Plan Proj ect Sections Detailed Cost Estimate Project Selection Cost of Energy Implementation Schedule Geology Hydrology Environment References APPENDICES -iii- FOREWORD (C) Purpose and Scope of ReP9rt This report is to document the results of a reconnaissance level study of the Cathedral Falls Project near Kake on Kupreanof Island in Southeast Alaska. The objective of the study is to determine if an application for license to the Federal Energy Regulatory Commission (FERC) should be made. An evaluation of energy generation alternatives for Kake was also made. The scope of the study includes the following work items: I . 2. 3. 4 • Size installation and estimate project power and energy production in relation to system loads. Prepare reconnaissance level analyses, preliminary design, geologic maps and layouts of appurtenant structures. Identify the potential environmental impacts of the project. Make a preliminary assessment of the safety hazard if any, caused or introduced by the project. 5. Estimate the construction, operation and main- tenance costs and service life of the project. 6. Evaluate energy alternatives and prepare an economic analysis of project. 7. Prepare a final report documenting the studies. Background and Previous Studies Studies of hydroelectric power development in the Kake area have focused around the development of Gunnuk Creek, a stream which passes through Kake, sinf7 studies completed by the Federal Power Commision in 1947 [1]-. An inventory study [2] prepared for the Alaska Power Authority (APA) in 1977 also selected Gunnuk Creek as the site for power development. That study mentioned Cathedral Falls as an alternative site for development; however the site was deferred for development in favor of Gunnuk Creek because the Gunnuk Creek Project was planned for seasonal regulation, whereas the Cathedral Falls Project would be run-of-river. II Reference listed in Appendix D. C-F-l .. Field investigation of the Gunnuk Creek Project, discussed later in this report, revealed that seasonal regulation would not be practical. Cost comparisons showed that a run-of-river project could be developed more economically at Cathedral Falls. Therefore that site was selected for the present study. Authorization The work was carried out under a contract between the APA and Harza Engineering Company, effective as of June 1, 1979. Funds for the study were provided by the State of Alaska. Acknowledgements Harza acknowledges and appreciates the valuable assistance and advice offered by the staffs of the following agencies: Alaska Power Authority Alaska Power Administration Tlingit & Haida Regional Electrical Authority U.S. Forest Service, Tongass National Forest U.S. Geological Survey Alaska Department of Fish and Game C-F-2 Chapter C-I PROJECT SETTING Location and Access The Cathedral Falls project is located at latitude 56 0 54'N and longitude 133 0 43'W, near the town of Kake on Kupreanof Island in Southeast Alaska. See Exhibit C-l. The Project develops the head between the top and the bottom of a falls on Cathedral Falls Creek at a point about 0.5 miles upstream from Hamilton Bay. Hamilton Bay is an arm of Keku Strait. Access to the damsite and the powerstation site is gained by all-weather logging roads. Population ~ Economy The Project would serve the town of Kake and the Clear Creek Logging Company (CCLC) at nearby Portage Bay. The majority of the inhabitants of the project area are Alaskan Natives, predominatly Tlingit Indians. The population of the area is about 700 and accounts for almost all the population of Kupreanof Island. The major commercial activities of the project area are fishing and forestry. A cold storage plant is currently under construction in Kake. Electric Power System Utilities Kake is served by the Tlingit and Haida Regional Elec- trical Authority (THREA), a rural electric utility with offices in Juneau, Alaska, which serves 5 towns in Southeast Alaska. CCLC is supplied by the Kake System. Existing Facilities All power in the project area is generated by small diesel-electric units located in Kake. The power is distributed from the powerstation and there are no transmission lines interconnecting the town with other areas. Table C-I-l lists the generating units serving the area. all units are owned by THREA. C-I-l Table C-I-l KAKE ELECTRIC SYSTEM EXISTING DIESEL GENERATING FACILI'rIES Unit No. -r- Nameplate Unit Capacity, kW 1/ Total Firm- 2 3 4 500 500 300 300 !! Largest unit out of service. Power Market Forecast 1600 1100 The forecast of future electric power needs is based on a current forecast prepared for the utility(THREA), and on discussions with the large private industries in the area (CCLC and the cold storage plant). A forecast of the power and energy generation requirements in the project area is shown on Table C-I-2. Table C-I-2 PCWER AND ENERGY GENERATION REQUIREMENTS 1978 1983 1988 1993 (a ctual) Peak Dema nd, kW THREA 430 560 680 820 Cold Storage 370 370 530 Enersy Generation, MWh/yr THREA 1690 2220 2670 3220 Cold Storage 1170 1170 1680 Future requirements for THREA in Kake have been estimated by a Rural Electrification Administration (REA) team [3] in cooperation with THREA. The current forecast, made in May 1979, is substantially lower than previous forecasts, basically because the previous forecasts were overly optimistic and re- cent rate increases have curtailed increases in per capita consumption. Over the ten-year forecast period the REA pre- dicted per capita consumption to remain constant with load growth coming from new connections. The combined load served by THREA is forecast to increase at 3.8 percent per year. C-I-2 CCLC has no plans for any major increase in power consump- tion. The cold storage plant is being built by the Kake Tribal Corperation, the local native village corporation. The Corpo- ration plans to install its own generating units, according to present plans. The Cathedral Falls Project will therefore be analyzed with and without that load. Topography Kupreanof Island has rolling, rugged mountainous terrain rising to 3800 feet at Portage Mountain, near Petersburg. Elongated hills, rising to El. 500, muskegs, and shallow lakes characterize the project area. Cathedral Falls is about 75 . feet high with the base of the falls near tidewater at El. 24. Hillside slopes above the falls are moderate and below the falls are steep. Geology The falls was apparently developed by the headward deepen- ing of the stream after rebound of the area following melting of a glacier. Rock in the area of project structures is part of the Permian-pybus and Triassic-Hamilton Island Formations and consists of fairly hard limestone. Earthquakes are common in the project area and the Project could be subject to severe shaking. More information on project geology is presented in Appendix C-A. Hydrology The climate of the project area is largely maritime with occasional incursions of continental air masses. The climate is mild and humid with much precipitation. Average annual temperature is 40-45°F with lows ranging from slightly below OOF in the winter to highs close to 90°F in the summer. Pre- cipitation varies greatly with elevation and location. At Kake mean annual precipitation is about 55 inches. Cathedral Falls Creek has a drainage area of 27 square miles and an average annual inflow of 103 cfs or 3.8 cfs/mi2. June, July, and August are low flow months with average flows below 60 cfs. High flow months are October and November, with average flows of 160 cfs or greater. More detailed information on project hydrology is presented in Appendix C-B. Hydrologic information relating to project operation is presented in Chapter C-III. C-I-3 Ecology Vegetation in the project area is typical of hemlock-spruce coastal forest with considerable muskeg areas. The area has been logged. Wildlife in the project area includes black bear, deer, moose, and wolf as well as many of the 200 bird species common to Southeast Alaska. Cathedral Falls Creek is catalogued as an anadromous fish stream and reportedly supports spawning runs of pink, churn and coho salmon. More information on ecology is presented in Appendix C-C. Project impacts are discussed in Chapter C-II. C-I-4 Chapter C-II THE CATHEDRAL FALLS PROJECT General Description Introduction The Cathedral Falls Project will provide energy to meet a part of the Kake system requirements and thereby replace some of the energy demand that would have to be provided by diesel generators. The falls provides an opportunity to develop a net head of about 87 feet without the need for excessive structures. The site does not allow for the economic development of reser- voir storage. The plant can provide some dependable capacity but will be primarily a source of energy when water is avail- able. This Chapter gives a description of the Project, the functional preliminary design of the major project elements, the schedule for the construction of the project, and the estimated project costs. Project Arrangement The Cathedral Falls Project will consist of the following principal elements: a. A low concrete gravity dam across the river, founded on rock, with an uncontrolled spillway over the highest part of the dam in the river section. b. An intake and an emergency closure gate for the power conduit and a temporary diversion conduit located through the dam at one side of the spillway. c. A power conduit 470 feet long (including 360 feet in the tunnel and 110 feet of exposed steel penstock) to convey water down to a powerhouse located near the base of the present waterfall. d. A powerhouse containing two turbines, generators and electrical switchgear and an adjacent switchyard to contain transformers and transmission pull-off structures. e. Other facilities including an access road and trans- mission line. C-II-l Exhibit C-2 shows a plan of the project general arrange- ment. Exhibit C-3 shows sections through the major structures including the dam and spillway, the penstock and power tunnel and the powerstation. A summary of significant data relating to the project is shown on the table at the end of the summary letter. Project Functional Design The Project will be designed to provide energy to the town of Kake and its environs in proportion to the flow available in the river. The plant will operate essentially as a run-of- river plant. The proposed reservoir will provide only minimum pondage, which can be used to regulate flows on an hourly basis provided there are no adverse effects on anadromous fish. Hydroelectric Power Production The powerplant will have two generators rated at 375 kW each, powered by fixed blade propeller turbines of 527 Hp each. The total installed generating capacity will be 750 kW. At full utilization the Project will produce 3680 MWh in an average year. Gross operating head will vary from 90 feet to 85 feet using 5 feet of drawdown available for pondage when inflow is less than turbine discharge capacity. Geology, Foundations, and Construction Materials A detailed description of the site geology is presented in Appendix C-A. Formations at the site are limestone, which is a relatively soluble rock. There is some minor evidence of solution of the limestone, such as widening of joints at the falls and pitting of the cliff at the falls. However, no evidence of widespread or deep solutioning of the limestone was seen. The geologic history of the area, which is of rebound following glaciation, suggests that solutioning would be shallow and localized. It is not anticipated that solution would have a significant impact on the Project, although this should be investigated during the feasibility study. Two geologic formations form the bedrock in the vicinity of the Project. The Permian-Pybus Formation consists of a series of thick beds of light grey to tan dolomitic, finely to C-II-2 .... medium crystalline, hard limestone with irregular nodules of limey chert or cherty limestone. The Triassic-Hamilton Island Limestone formation outcrops at the end of the falls and upstream where it is in fault con- tact with the Pybus Formation. The formation consists of thinly bedded ( 1/4" to 2"), laminated, dark grey to black, hard argillaceous limestone; interbedded with dark grey to black, thinly bedded chert and argillite. Upstream of the falls, the Hamilton Island Limestone is folded into a sharp southwesterly trending syncline. Cathedral Falls Creek is located east of the Chatham Strait Fault in an area that is locally inactive seismically. No active faults have been recognized in the area. However, as all of Southeast Alaska has been seismically active, provisions for strong acceleration forces will be incorporated into pro- ject design. Although the powerplant for Cathedral Falls Creek will be located near tidewater, the site is considered to be safe from tsunamis. This consideration is based on the protection afford- ed by Baranof and Kuiu Islands from tsunamis originating on the Fairweather Fault and by Kuiu Island from tsunamis that could originate on the Chatham Strait Fault. Stripping for the dam should remove organic matter, soil, and loose rock to permit examination of the bedrock surface. Stripping is estimated to be about 2 feet in the channel and 5 feet on the abutments. Zones of weak rock should be excavated and cleaned with a water jet and backfilled with concrete. Open joints should also be jetted clean and slush grouted. It is estimated that grout holes for the proposed grout curtain should be drilled about 10 feet deep. This curtain, which should be an exploratory type, should have holes angled at 45° to provide a greater incidence of interception of steeply dipping joints. Penstock support and bend anchors should not require any special provisions for anchoring. The small tunnel envisioned for the penstock should gen- erally require only nominal support, consisting of rock bolts with wire mesh in the crown. Provis ions however, should be made for greater support in the event fault zones are encountered. C-II-3 The powerplant, which will be located near the cliff bordering the upstream or northeast side of the pool formed by the Falls should be founded on bedrock, assumed to be at a shallow depth below the pool surface. Slopes behind the powerplant should be scaled of loose rock and then stabilized with rock bolts and wire mesh. Large trees that could be blown down and cause damage to the powerhouse should be cut and removed. Concrete aggregates for the dam, penstock supports and powerhouse substructure will be obtained from a quarry along the existing forestry road passing the project site. Potential quarry sites can be developed within one mile of the dam site. Description of the Project Facilities ~ and Spillway The dam will be a concrete gravity dam with an uncontrolled ogee crest spillway over the deeper, river section. The crest of the spillway is set at elevation 115.0 and the top of the dam at elevation 125.0. The dam, with a backslope of 0.7h:lv, will have a maximum height of 27 feet in the river section. The spillway is dimensioned to pass 70 percent, or 8600 cfs of the peak instantaneous inflow from the probable maximum flood with the reservoir surcharged to the top of the dam. This results in a spillway slightly narrower than the existing river channel and confines discharge to the existing channel. No storage effect is considered available to attenuate the peak inflow. When passing the probable maximium flood, the top of the dam will be surcharged by 1.5 feet of water. The dam will be stable under this head and little damage to the abutments would be expected. A grout curtain will be provided along the entire length of the concrete dam near the upstream face of the dam. The entire foundation of the dam and spillway will be stripped to sound rock. The dam and spillway are estimated to require about 1500 cubic yards of concrete. A timber buttress dam and spillway was considered as an alternative to the structure described above. The timber dam and spillway was found to be more costly than the selected structure because concrete would be required for footings, and the timber itself would have to be imported from Seattle, Washington, the nearest location where it could be pressure treated. C-II-4 Power Intake The power intake will be located at the left side of the existing river channel, between the spillway training wall and the south river abutments. The power intake will have two bell mouthed entrances divided by a center pier and be provided with guides and seal plates on the upsteam face of the dam for inter- chang ing trashracks wi th bulk head ga tes \oJhich can be lowered from a hoist at the top of the dam. Water passing through the trashracks will have an average velocity of 3 fps through the net area at the maximum expected discharge. The intake water passages will have slots for emergency closure gates operated from hoists at the top of the dam. Downstream of the gate section a transition section will transform two rectangular conduits to one circular conduit. The intake will be set low enough to permit about a 5 foot drawdown of the reservoir from elevation 115.0 (the spillway crest level). Given the character of the stream, once the reservoir is created, it is unlikely that stones would be carried along to the area of the intake, permitting the intake to be set fairly low, close to the bed of the river. Siltation also does not appear to be a problem. Penstock and Power Tunnel A combined exposed penstock and steel lined tunnel, with a total length of 470 feet, will connect the intake to the power- station. The exposed penstock would be provided with a con- tinuous anchored concrete support sill to protect the penstock from erosion and floatation during large spillway flood discharges. The penstock is sized to allow for a possible future installation of two additional units to bring the total instal- lation to four generating units, with a corresponding discharge of 4x62=248 cfs, and a total power output of 1,500 kW. The tunnel will carry the power conduit down on a straight line from the head of the falls to the escarpment behind the the powerhouse. Economy and ease of construction normally dictate that tunnels have a minimum diameter such that the tunnel can be easily mucked out with rubber tired or crawler type front end loaders. Contractor preference has demonstrated that a tunnel which requires both steel support and a ventila- tion conduit would then have height and width of about 9 to 10.5 C-II-5 feet. Tunnel height and width of 9 feet appears to be adequate and are selected for this study. A steel liner is provided through the power tunnel as a continuation of the steel penstock. Concrete backfill will be placed behind the steel liner through the tunnel. Fiberglass reinforced plastic pipe was also considered for the liner but was rejected because of its lower strength than steel and because of the low temperature operating conditions at the site. Between the powerhouse and the tunnel outlet portal a pen- stock bifurcation will be provided to divide the penstock from 6.50-feet diameter to two 4.65-foot diameter pipes, one of which would receive a hemispherical bulkhead cover, thus permitting two additional units to be installed in the future. The other would be bifurcated again to feed the two generating units now proposed. The penstock manifolds would be supported on a rock back- fill between the tunnel portal and the powerstation and would be encased in concrete. The escarpment face over the tunnel outlet portal will be cleared of possible rock spalls and be stabilized with rock bolts and wire mesh. Powerplant The powerhouse will have a reinforced concrete substructure with a prefabricated metal superstructure above the generator room floor. Unit width would be approximately 9 feet. The turbines would be mounted in formed pits 6 feet square above the draft tubes. The overall dimension of the powerplant superstructure containing two units and an erection area will be 32 feet long by 12 feet wide by 20 feet high. The two turbines will be vertically set fixed blade propeller type, available as standard inventory "package" models, rated to produce at least 527 horsepower at a net head of 87 feet at 1200 rpm. At the rated output and head, each turbine will discharge 62 cfs. Inspection of the present outlet channel below the existing falls indicates that the streambed would be unlikely to degrade below its present level. C-II-6 The generators and turbines will be connected by a vertical drive shaft. The generator will be rated at 468.74 kVA, at 60° C temperature rise, 0.8 powerfactor and 60 Hertz. Each generator will have a continuous overload rating of IS percent. Switchyard and Transmission Circuit breakers will be of the air magnetic, or vacuum interruptor type as appropriate. They will be rated to inter- rupt the maximum expected fault current and will be used to put the unit on-line during the normal start-up sequence and to take the unit off line. Station service power will be supplied at 480-V through 3-phase dry-type transformers and 480-V circuit breakers. All protective relays and all control devices for complete manual and automatic operation of the generating units will be provided. Supervisory control equipment will be provided to permit remote control, indication, and communication of powerhouse generating data to a remote central control room located at Kake. This feature could be optional. The generators will be connected to a power transformer located in a small yard on the upstream side of the powerhouse. The transformer will be rated at 1078 kVa. The transformer will be connnected to the Kake substation by a single 12.S-kV circuit about 9 miles long. The powerhouse will be provided with a single light bridge crane, supported on separate columns and support beams to un- load and erect equipment during construction and to facilitate servicing. Accessory electrical equipment for the control and protect- ion of the powerplant and miscellaneous mechanical equipment will be provided in the powerhouse. Access Hoads An all-weather Forest Service road presently used for logging operations passes very close to either side of the darn site, crossing the creek about a half mile upstream of the darn site on a steel girder bridge. C-II-7 Access to the darn site can be easily obtained by extending short roads to one or both sides of the proposed darn site. Moderate gradients could be maintained. Access to the powerstation below could be developed by extending some secondary forestry roads, requiring new construc- tion of 0.6 miles of road to arrive at the powerhouse. Reservoir The reservoir created by the uncontrolled spillway crest level of elevation 115.0 will be about 0.7 miles long and will create a normal ponded depth of 5 feet at the existing bridge site. The reservoir will be surcharged above elevation 115.0 when floods are discharging through the spillway. However the probable maximum flood can be passed without submerging the bottom of the bridge girders. Clearing of the reservoir should be carried out in the small areas between the stream bed and EI. 115 on both sides of the stream. Spoil Disposal Overburden containing organic matter and decomposed rock removed from required excavations at the damsite will be tem- porarily stockpiled and then placed into the quarry excava- tion in compacted layers finished off with stable slopes and seeded. Environmental Aspects The potential environmental effects of the Project were identified and recommendations made for possible mitigating actions. Details of this study are presented in Appendix C-C. The damming of Cathedral Falls Creek above the falls would not affect the passage of anadromous fish since the falls serves as a natural barrier. The construction of the Project may cause some disruption to the stream's migratory salmonid populations below the falls. At the present level of study there do not appear to be any adverse environmental impacts of the Project of a magnitude which would prohibit its construction or greatly restrict its operation. C-II-8 ... Project Construction Project construction will be carried out by separate sup- ply and civil works contracts. A single civil works contractor will be engaged to build the project. The contractor will be required to construct access to the dam site and to the powerstation site, clear and prepare stag- ing areas near the dam site and the powerhouse site, and pro- vide for his power requirements during construction. Actual construction can be completed in a period of two years. The contractor will use the first spring season to build access to the site, occupy the site, establish his shops and working areas especially in the tunnel portal areas and mobilize his equipment and work force. First Year Before the contractor has completed his mobilization and finished assembling his shops and maintenance facilities, he will begin opening up his quarry for concrete aggregate and stripping the foundation areas for the dam and powerhouse of brush, overburden, and weathered rock. By the time the quarry has been opened up and the founda- tion prepared for pouring concrete, the contractor should have his crushing and batching plants erected and be ready for operation. Diversion would be effected in July of the first year by building a rock and earth cofferdam upstream of the dam and diverting the river though a 4 foot diameter, corrugated metal pipe along the north side of the Cathedral Falls Creek channel which would extend to the falls. The metal pipe would be set on a concrete bedding on sound rock through the dam foundation area such that it could be incorporated into the dam concrete structure as construction proceeds. It would be provided with a slide gate in a vertical set metal frame operated with a hand wheel. A concrete head wall 8 feet high would be provided to improve entrance conditions and provide rigidity and an anchorage and containment for the slide gate frame. When the dam is completed the slide gate would be closed in the month of July, normally the lowest flow month, the pipe extension to the falls downstream of the dam would be removed and the pipe plugged with concrete through the dam. After river diversion is effected, the contractor will begin work on the dam and should also be ready to begin work on the power tunnel and powerhouse below the falls. C-II-9 .. .. The total concrete to be poured in the dam is 1500 cubic yards. Assuming 20 foot wide monoliths and 5 foot high lifts, the largest pour the contractor will have to make in a 10 hour shift is in the order of 70 cubic yards. A 1.5 cubic yard capacity batching and mixing plant would be ample for the charging, mixing and unloading cycles to provide concrete as necessary. Concrete could be transported in 1 cubic yard buckets on flat bed or dump trucks and placed in the lifts by a 15-ton truck-mounted hydraulic crane. A construction access road could be maintained along the upstream face of the dam for that purpose, using approximately 6 feet of temporary fill through the river channel section, to carry the access road over the diversion conduit. The temporary fill would be removed when the dam is completed. Some turbidity would be created by the filling and removal, but the amount would be small and the duration brief. Excavation and support of the power tunnel should be carried out as early as possible in the first summer. Pre- liminary information indicates that a tunnel gradient of about 18 percent will be necessary. This slope can be negotiated by either rubber tired or crawler mounted construction equipment. The contractor should work up grade from the lower heading to facilitate drainage. Working one 10 hour shift per day and averaging 25 days per month, he should be able to complete the tunnel in two months. Access to the downstream tunnel portal would be gained by the powerstation access road. Penstock assembly must begin at the end of June in the first year so that sections to be embedded in the dam will be available when needed and the erection of the penstock including the portion passing through the tunnel can proceed to comple- tion in the fall of the first year. During the first year the transmission line will be cleared and pole erection initiated. It is expected that work will be significantly curtailed through the winter months of December, January, February and March due to snow, Im>l temperatures and limited hours of day- 1 ight. If winter conditions are not too severe, or should the con- tractor need to make up lost time, it would be possible to con- tinue on the powerhouse and transmission line er~ction and finish placing the tunnel liner during the winter season. Work would be expected to be less productive and would not be neces- sarily under normal conditions • C-II-IO Second Year Early in the spring of the second year the contractor will complete the erection of the powerhouse prefabricated metal superstructure and installation of auxiliary electrical and mechanical equipment. He will then commence installation of the turbine, genera- tors and power transformer. Four months are available for the installation of this equipment. The transmission line pole erection will be completed and the conductors strung. All remaining concrete pours on the dam and spillway will be completed such that final closure of the diversion conduit can be made in July, as previously described. By the end of August in the second year the contractor can begin testing the units and make the necesssary adjustments and corrections to bring the units on line on or before the end of November. Clean up and restoration of all construction areas at the dam site and around the powerhouse will go on simultan- eously with testing of the units. The contractor will remove his equipment and materials from the site during October and November. The construction schedule is indicated on Exhibit C-7. Project Costs The construction and operation and maintenance costs of the Project are estimated as discussed below. The costs are estimated at September 1979 price level. Construction Cost The construction cost of the Project is summarized on Table C-II-l and a detailed estimate is shown as Exhibit C-S. The construction cost includes the direct cost of civil works, contractor's overhead and profit, purchase and instal- lation of equipment, contingencies, engineering, and owner's administration, but excludes price escalation beyond September, 1979, and interest during constructio~. Detailed estimates of quantities are calculated from the project plans, and unit prices or lump sum costs are estimated for each item of work. C-II-ll Table C-II-l CONSTRUCTION COST OF PROJECT (In Thousand Dollars at September 1979 Price Level) Item Mobilization Land and Land Rights Reservoir Clearing Diversion and Care of Water Dam, Spillway and Intake Waterconductor Powerhouse Mechanical and Electric Equip. Roads and Bridges Transmission Subtotal Direct Cost Contingencies (25% +) Total Direct Costs Engineering and Administration (20% +) Total Construction Cost Cost 500 17 38 195 1,028 1,539 126 402 444 497 4,786 1,197 5,983 1,117 7,100 The items within each project feature are estimated either as part of a general construction contract or an equipment purchase contract. The unit costs of labor and locally avail- able construction materials were obtained from local sources. Construction equipment unit costs are developed from lower U.S. hourly rates adjusted to local conditions. unit prices were verified by checking recent bids on the Green Lake Project located near Sitka and by experience of the Corps of Engineers in Alaska. Unit costs for the principal items of work are based on a construction plan designed to implement the Project in accordance with the schedule as shown on Exhibit C-7. The direct cost estimated for the permanent equipment includes purchase, delivery, and installation. The major equipment items include the turbine and governor, generator and exciter, transformer and terminal equipment, switchgear, and powerstation crane. The price of major equipment items are estimated based on recent experience with similar equipment and, when possible, on preliminary quotations from manufacturers. C-II-12 To allow for unforeseen construction problems, changes in design, and errors or omissions in estimating, a contingency allowance of 25% is added on all costs. Based on data obtained from other hydroelectric projects, an allowance of 20% for engineering and owner's overhead expenses is added to the total of the preceding costs. This consists of 17% for engineering and supervision of construction and 3% for owner's overhead costs to be charged against project construction. Operation and Maintenance Cost The Project would be equipped for remote control operation from Kake. Routine operation and maintenance expenses are estimated at $40,000 per year based on FERC data adjusted for automatic operation and conditions in Alaska. C-II-13 .. Chapter C-III PROJECT SELECTION AND OPERATION This chapter describes the selection of the stream regula- tion characteristics for the Cathedral Falls Project and the type, number, and capacity of generating units. The selection of the Cathedral Falls Project from among other possible sources of generation is discussed in Chapter C-IV. The operation of the Project in relation to power system loads is also discussed in this chapter. Stream Regulation Characteristics The Cathedral Falls Project will be a run-of-river hydro plant with pondage available for hourly regulation when stream- flow is less than turbine discharge capacity. The area-volume curve for the Cathedral Falls reservoir is shown on Exhibit C-5, Sheet 1 of 4. To regulate the average annual flow in the creek a volume of about 10,000 acre feet would be required. This volume is far beyond the capacity available. Therefore the project will have to operate as run-of-river. Daily pondage, however, could be provided. The volume required for daily pondage depends on the total installed capacity of the Project. This is discussed in the following section. Type, Number and Capacity of Generating Units As an initial trial, the total hydraulic capacity of the Project was assumed to be equal to the average flow in the river (103 cfs) divided by the power system capacity factor (0.45) or 229 cfs. The head on the project was established by assuming a reasonable height of dam which could be developed at the site. A 35-ft high structure could pond water to El. 125 and develop an average net head of 94 feet. The total capacity available from the Project, assuming an efficiency of 85 per- cent would be as computed by the following formula: kW available= 229 cfs x 94 ft x 0.85 11.8 = 1550 C-III-l .. Assuming some overload capacity in the units, the in~ stalled capacity was set at 1500 kW, which is also the maximum installed capacity for a minor project under current FERC regulations. To provide daily regulation of 1500 kW a storage volume of about 110 ac-ft would be required. This volume could be provided with a drawdown of 10 feet from El. 125. If one half the capacity (750 kW) were installed the maximum reservoir level would be at El. 120 to provide daily regulation. If no regu~ lation were required, the maximum reservoir level could be set at El. 115. Each lowering of reservoir level would lower the dam height and reduce project costs. An economic comparison was made of the benefits gained from flow regulation with the costs of providing the regulation. Regulation is the ability of the project to control inflow so as to meet, hourly, daily or seasonal loads placed on the plant. To determine the benefits gained from flow regulations, the energy from the Project, which would replace diesel energy, was computed for the following four cas es: 1. 1500 kW installed with regulation. 2. 1500 kW installed without regulation. 3. 750 kW installed with regulation. 4. 750 kW installed without regulation The hydro energy which could be absorbed by the system in each year of project operation was computed for the four cases by comparing the output of the hydro project as obtained from the duration curve of daily flows (see Exhibit C-5 Sheet 2 of 4) with the annual system energy requirements as obtained from the system load-energy curve (see Exhibit C-5, Sheet 3 of 4). The first year of project operation would be 1984 and the Project would have a life of 50 years. Exhibit C-5, Sheet 4 of 4, shows the average hydro energy produced in each year of the project's life. In some years energy production will be less than average and in some years more. Detailed analysis should be made at the feasibility level to determine the ranqe of e nercJY ou tpu t. 'l'he benef it-cos t analy s is showed tha t addi ng dai ly regu- 1ation and installing 1500 kW was only justified at interest rates below 2 percent assuming no fuel price escalation or 4 percent assuming 2 percent differential fuel price escalation. Therefore an installation of 750 kW was investigated and is selected as the installed capacity of the project. No daily C-III-2 regulation was provided; however a minimal amount (about 30 ac-ft) of storage would be available to regulate unit flow during low flow periods. A two unit installation was selected for the Project to provide some reliability and to allow the units to operate at a higher efficiency under minimum flows. Each of the units could be of a "package-type" including a fixed blade propeller turbine. This type of unit was selected because of the suitable head on the Project and the low cost of this type of unit. In the feasibility study more detailed analysis, will be required to determine the most economical expansion program for the Project. Power and Energy Production The Project would provide replacement energy in the system. The Project would also be able to produce about 120 kW of power, 90 percent of the time. Some drawdown might increase this amount slightly. At the time when the water supply permits (about 25 percent of the time) the project could produce 750 kW. This capacity could be totally absorbed in the THREA system by 1991. In the Project's initial year of operation it will supply 1810 MWh of energy, under average flow conditions, or about 80 percent of the system's requirements. The Project will be totally absorbed by the system in 2016, in which year it will produce 3680 MWh, or about 45 percent of the system energy requirements in that year. C-III-3 Chapter C-IV ECONOMIC ANALYSIS Methodology An evaluation at the reconnaissance level indicates the economic attractiveness of the Project. The costs of producing the same power and energy as by an alternative source of generation is taken as the benefit accruable to the Project. The benefits and costs of the Project are compared under various economic assumptions to determine benefit-cost (B/C) ratios. As an additional indication of economic attractiveness, the annual cost of energy produced by the Project was compared with the annual cost of generation from alternative sources over the Project's life. Alternative Sources of Power The various types of projects available to serve the pro- ject area were screened to determine the most likely alternative source of generation. Costs were estimated for that alternative. The following types of alternatives have been suggested: diesel, other hydro, wood waste, wind, solar, interconnection with other systems, and energy conservation. Of these alterna- tives, the first three offer the most promise for the project area and are discussed in more detail at the end of this sec- tion. The others are not as attractive for the reasons pre- sented in the following paragraphs. Wind and Solar Wind is a form of solar energy. Both the use of wind to drive a generator directly and the use of solar energy for heating or for conversion to electricity are not practical alternatives for Southeast Alaska in the near and intermediate term. A wind demonstration project sponsored by the State of Alaska is currently underway in the Aleutians. The project is small, will require an energy storage system to provide continuous energy, and present economics do not justify the installation of such units on even a small scale commerical basis. Direct use of solar energy has found increasing application in areas of the U.S. with abundant sunshine which is not the case in Southeast Alaska. C-IV-I Load Management and Energy Conservation Load management and energy conservation could be used to reduce power and energy requirements to limit growth in demand. These measures have been tried experimentally in large market areas and have met with questionable success. In this project, the primary function is to supply energy to replace existing diesel generation. By applying load management and conserva- tion measures, existing loads could probably not be signific- cantly reduced. Any slowdown in growth rate effected by these measures would only delay the date by which the Project would be fully absorbed by the system and would not significantly affect project economics. Interconnection The nearest large load center to the project area is Petersburg. There is presently no surplus power available in Petersburg, but the Tyee Lake Hydroelectric Project, which is currently under study, could be utilized to meet the energy needs of Kake. That project is presently designed to serve Wrangell and Petesburg. APA's consultant for the Tyee Lake Project, Robert W. Retherford and Associates, estimated the cost of a 115-kV transmission line for that project in a roadless area to be $130,000 per mile. A 69-kV line would be required to supply Kake from Petersburg. The line would include an overhead section, 52 miles long, and two submarine cable crossings with a combined length of one mile. Assuming that a 69-kV line would cost 70 percent of the 115-kV line, and that a submarine cable crossing would be twice the cost per mile of a surface line, the Petersburg-Kake line would have a direct cost of about $4.9 million. In order to be consistent with the estimate for the Cathedral Falls Project, contingencies (25%) and engineering and administration (20%) are added to the $4.9 million to ob- tain a total construction cost of about $7.4 million. This value is for the transmission line from Petersburg to Kake and does not include the cost of of upgrading the Wrangell-Peters- burg circuit from th presently planned 34.5-kV to 69-kV or 115-kV which would be required to transmit power to Kake. Also not included in the this value is the cost of additional genera- ting capacity at the Tyee Lake Project. The construction cost of the transmission line is about the same as the cost of the Cathedral Falls Project. Assuming that the operating characteristics of the Tyee Lake Project are such that firm energy and dependable power can be provided to C-IV-2 Kake, the interconnection would generate greater benefits than the Cathedral Falls Project. With 2 percent differential fuel escalation, the interconnection could generate benefits suffi- cient to cover construction costs of $12.5, $7.8, $6.0, and $4.6 million assuming interest rates of 2,5,7, and 9 percent respec- t ively. Thus, interconnection might prove to be slightly better than the Cathedral Falls Project, however, the decision should be based on a more detailed reconnaissance-level evaluation. The evaluation should include an estimate of all costs associat- ed with the interconnection such as the cost of upgrading the Wrangell-Petersburg circuit and the cost of incremental capacity at Tyee Lake, as well as the cost of the Petersburg-Kake line itself. Operation studies should be made of the combined Wrangell-Petersburg-Kake system to determine the amount and reliability of power and energy supplied to Kake. Other Hydro The earliest published evaluation of hydroelectric power sites in Sotheast Alaska was completed by the Federal Power Commission and the U.S. Forest Service in 1947 [1]. That study identified one site, Gunnuk Creek, on Kupreanof Island. In the mid-1960's the Alaska Power Administration made an inventory study of hydro-electric sites in the State of Alaska. As a result of that study one additional site, Towers Creek, was identified on Kupreanof Island. In 1977, Robert W. Retherford and Associates [2] completed an inventory study which identified the Cathedral Falls site in addition to the Gunnuk Creek site. The Towers Creek site was apparently rejected because the river is an anadromous fish stream and is far from Kake. Of the two sites, Gunnuk Creek and Cathedral Falls, the Retherford study selected Gunnuk Creek because it is closest to the load center and offers seasonal regulation. The original scope of work for the present study called for an investigation at the Gunnuk Creek Project. The project concept for Gunnuk Creek as developed by Retherford would include two dams built for storage approximately 3 miles upstream of an existing timber buttress darn which is being used by Kake for a municipal water supply. That darn is about 0.5 miles from the mouth of Gunnuk Creek at Kake (see Exhibit C-l). A 2800 foot long penstock would be built from the existing dam to a powerstation located at tidewater. The project would have an installed capacity of 1800 kW. The storage reservoirs would form a pool to El. 500 C-IV-3 and provide 14,500 ac-ft of storage, which would regulate a flow of 75 cfs according to the Retherford study. A field reconnaissance was made for that project. The results of the reconnaissance were as follows: a. The storage reservoir area below El. 500 has not been cleared and about 600 acres would have to be cleared. The cost of land purchase and clearing would be about $8 million. b. Field elevation measurements made by altimeter at the storage sites showed the stream-bed elevations to be lower than shown on the U.S.G.S. 1:63.360 scale map. c. Surveyed stream cross-sections at the storage sites showed the abutments to be flatter than might be inferred from the U.S.G.S. map. A layout was made for the storage dams. It was found that the dams would have a maximum height of about 80 feet on the west fork and 110 feet on the east fork to create a reservoir with a water surface at El. 500 as selected by Retherford. The total volume of the dams would be about 500,000 cubic yards. The estimated cost for the rockfill for these dam would be $14 million. Adding the required spillway, the down- stream power dam, 2800 foot penstock and powerstation would obviously make the project prohibitively expensive. A run-of-river project located at the existing timber dam would not develop the head as economically as could be devel- oped at Cathedral Falls, even taking into account the longer transmission distance from Cathedral Falls to Kake. There are also several environmental factors, discussed in Appendix C-C, which make the Gunnuk Creek site not as desire- able as Cathedral Falls. The most significant are: (1) Water quality in the Gunnuk Creek storage reservoir could deteriorate over the long term, even if the inundated area were cleared, which could affect municipal water supply and the stream's migratory salmonid population; and (2) A powerplant located at tidewater would reduce or eliminate streamflow in the reach of the stream below the timber dam, which supports salmon spawning activity. The Cathedral Falls site was selected over the Gunnuk Creek site for the above reasons. A brief map study was made C-IV-4 of other potential hydro projects near the project area. The study did not find any site more attractive than Cathedral Falls. Wood A wood-waste fired plant could be used for generation in the project area. Recent information available on a 10-MW wood- waste plant to be constructed in Northern Michigan indicates that the construction cost of the plant, which uses new equipment, would be about $1500 per kilowatt at September 1979 price levels. Adjusting the unit capacity down to 2-MW (the capacity which could serve the project area in the next 20 years), and adjust- ing for construction conditions in Alaska, would, conservatively, double this cost to $3000 per kilowatt. At this capital cost, fuel (40% moisture) would have to be available at the wood-fired plant at a cost of less than $19 per ton and the rate of interest could not exceed 9%, in order for the project to be more economi- cal than diesel generation. Another promising source of wood-fired generation, in the 500 kW unit capacity range uses a gasifier to convert solid fuels containing carbon into a gaseous fuel by means of a thermo-chemical reactor. The gaseous fuel would then be burned in specially equipped conventional diesel units. Such a plant could also use coal or peat as a fuel. Alaska Village Electric Cooperative (AVEC) is currently sponsoring a demonstration pro- ject using biomass conversion. The biomass conversion unit and the equipment required to burn the gas in the existing diesel engine is estimated to cost about $700/kW at September 1979 price levels, including con- tingencies and engineering. This cost would apply to the equip- ment required to supply a 500 kW unit. The unit would have to operate on dual fuel (10% diesel oil, 90% gas) and the fuel moisture content could not be more than 30%. At this capital cost, waste-wood fuel (30% moisture) would have to be available at a cost less than $58 per ton in order for the project to be more economical than diesel generation. Those costs assumed: existing diesel units will be used: the interest rate could not exceed 9 percent; and there is no differential fuel escala- tion. The capital cost of the biomass gas fired plant assumes the use of existing diesel engines and does not include the cost of the engine-generator set. The cost of wood in Kake is difficult to estimate, since there is no local wood processing facility in this town. The Alaska Timber Corporation in Klawock sells dry wood chips for $65 per 2400 pound unit, FOB Klawock. Adjusting this cost to C-IV-5 an equivalent moisture content (30 to 40 percent) and heat value, equivalent unit weight and adding transportation and handling costs gives a cost of about $55 per ton delivered in Kake. In the lower 48 states, wood fuel is generally available to wood-fired plants located in forest areas at a cost of about $15 per ton (40% moisture). Assuming this cost to double for Alaskan conditions, wood fuel should cost $30 per ton if it were available in Kake. Thus, wood for power generation might cost from $30 to $55 per ton. At this price, the wood fuel might also be suitable for use in biomass conversion units. The wood fuel costs presented in this analysis are to the appraisal level. These costs are sufficiently attractive that a reconnaissance level study should be made of the viability of developing a wood-waste fired plant to serve Kake. Diesel At present, the entire load in the project area is met by diesel oil-fired electric generating sets. This is presently the most viable alternative source of generation in the project area. Recent offers received by the THREA for 400-kW diesel electric units averaged about $235 per kilowatt, FOB Seattle, at September 1979 price levels. Including transportation, erection, contingencies, and engineering the cost of a unit installed in the project area is about $600 per kilowatt. Annual operation and maintenance cost exclusive of fuel is estimated to be about $120,000 per year for a plant in the pro- ject area. At present (July 1979), diesel fuel in the project area costs about $0.65 per gallon, delivered. This price is expected to increase over the next several months in line with trends in price increases experienced with gasoline. The price of $0.65 per gallon does not reflect the recent 24 percent incease in the reference price of Arabian light crude announced by OPEC in July. To reflect the short term upward pressure on the price of petroleum fuels, a price of $0.80 per gallon is used as the base price of diesel oil in the present economic analyses. Fuel consumption in the project area averages 8.4 kWh/gal, which gives a fuel cost of $0.095/ kWh. C-IV-6 Economic Criteria Certain basic criteria are established for the economic analysis. These criteria define interest rates, fuel esca- lation rates, project life, and period of analysis. Four inter- est rates, 2,5,7, and 9 percent, are used in the analysis. Differential fuel escalation rates of 0,2, and 5 percent are assumed for diesel fuel. Differential fuel price escalation is the rate at which fuel prices are assumed to escalate over and above the normal inflation rate. The average physical and economic life of the hydroelectric project is assumed to be 50 years and that of the diesel units to be 20 years. The period of study for comparison is taken to be equal to the life of the hydro project: 50 years. Economic Comparison The economic comparison of the project is made using life cycle costing. By this method estimates of costs and benefits are made in the year in which they occur and are then discounted to a common date at a given interest rate. The period of analysis is 50 years. In the analysis costs and benefits are discounted to Jan. 1, 1980. Analysis is performed to determine the benefit-cost ratio including and not including the cold storage plant to see if project economics would be improved by adding that load. The results of the analysis for this are shown on Table C~~. Without Cold Storage Fuel Escalation, With Cold Storage Fuel Escalation, Table C-V-l CATHEDRAL FALLS PROJECT Benefit-Cost Ratios Interest 2 5 % 0 0.99 0.68 2 1.48 0.94 5 3.34 1.81 % 0 1.07 0.75 2 1.60 1.04 5 3.54 1.98 C-IV-7 Rate% 7 9 0.54 0.44 0.71 0.56 1.25 0.89 0.60 0.49 0.79 0.62 1.38 1.01 The benefit-cost ratios given on Table C-V-l show that the Project is economically attractive at an interest rate of 2 percent assuming no fuel escalation. For the purpose of evaluating the Project, a fuel escalation rate of 2 percent is recommended as being representative of future trends. At that rate, the Project would be economically viable at an interest rate of about 5 percent. The addition of the cold storage load improves project economics slightly. Cost of Energy The cost of energy from the Project and the alternative is calculated year by year over the life of each. The calculations are made assuming a cost of money of 2,5,7, and 9 percent and assuming a differential fuel escalation rate of 2 percent. Normal inflation is assumed at 4 percent per year over the life of the project. The computations are made assuming the cold storage, would not be interconnected. The annual cost of energy includes 'allowances for amortization, interest, operation, maintenance, administration general expen- ses and insurance. Taxes are not included since it is assumed that tax exempt financing will be obtained. The cumulative total cost of energy and the cumulative present worth of the cost of energy are also determined. A discount rate of 8 per- cent is used for present worth calculations. The results are shown graphically and in tabular form on Exhibit C-6. As can be seen from the exhibit, the cost of energy from the Project is less than that from the alternative after 1988. C-IV-8 Chapter c-v RECOMMENDATIONS AND IMPLEMENTATION Recommendations The economic analysis, presented in the previous chapter shows that the Project is economical at interest rates of 5 percent or less, assuming differential fuel escalation of 2 percent. Recommendation for future study of the Project is therefore contingent on financing. An organizational framework should be developed as soon as possible to investigate financ- ing alternatives. A feasibility study should be made of the Project and either a Declaration of Intention or Application for License should be filed with the FERC if acceptable financing can be obtained. A reconnaissance-level study should be made for use of wood either as a fuel for direct combustion in a boiler to drive a stearn turbine or by conversion to low-Btu gas which can be burned in an internal combustion engine. The study should include site specific studies for Kake and might also include a general study of the use of wood as a fuel for electricity generation on a regional and statewide basis. Also, a brief reconnaissance-level study should be made of the feasibility of interconnection with Petesburg. Organizational Framework and Financing THREA should be the implementing agency for the Project. THREA is the agency charged with power generation and distribution in Kake and most of the rural area of Southeast Alaska. THREA also has the possibility of obtaining low in- terest federal financing for the Project. The Alaska Power Authority might want to serve as an advisor to THREA to provide impetus and guidance during project implementation and to represent the State of Alaska's interest in regional power development. THREA, with APA support, should make contact with the REA to determine if the Project would qualify for low interest financing. At the same time any possibilities the State or THREA might have for obtaining low interest financing from other sources should be explored. If low interest financing is not available or if wood- fired generation is more attractive than the Project, future studies of the Project should be deferred. If acceptable C-V-l . " .. financing is available and wood-fired generation is not economically attractive, the Project should be implemented as described below. Preconstruction Activities A feasibility study of the Project should be started as soon as possible. The scope of the feasibility should be aimed at satisfying the requirements for a FERC license application, whether or not one will eventually be required. The study should be prepared in close cooperation with state and federal agencies • The exact scope of the study, particularly in relation to environmental studies, will depend on the requirements of the agency under whose jurisdiction most of the affected resources would fall. In this case anadromous fish would be the resource most affected and the Alaska Department of Fish and Games (ADFG) the responsible agency. Also the U.S. Forest Service (USFS) should be included in project planning. Contacts should be made with ADFG and USFS at the time the scope of work is developed and then maintained throughout the study. The time schedule for the feasibility study will depend on the baseline data requirements of ADFG. A feasibility study with limited baseline data could be completed in one year. At that time a tentative decision on project feasibility could be made and financing and permitting arrangements could be initiated. At the same time environmental studies could continue to satisfy ADFG requirements. At the completion of these studies and before award of construction and equipment contracts, an addendum could be issued which would make a final recommendation on project feasibility, and final financing arrangements could be concluded. There has been some comment on the part of the USFS and the Kake Tribal Corporation, discussed in Appendix C-C, that it might be desirable for the Corporation to select, under the Alaska Native Claims Settlement Act, the lands upon which the Project would be built. The project lands are now part of the Tongass National Forest. If the Project were located on Corporation land, the Project would probably not require an FERC license. A Declaration of Intention would have to be filed with the FERC to determine if the FERC would have jurisdiction over the Project • The Project would be classified as minor (less than 1500 kw) under current FERC regulations. The licensing process C-V-2 ' .. ... .. .. could be completed in about one year. The review of a Delara- tion of Intention would take similar time. Therefore, there is no time advantage gained by the Corporation selecting the land. Unless there are other reasons for the selection, unknown at present, there does not appear to be any reason for the selec- tion to be made, except to avoid applying for a USFS Special Use Permit. Discussions should be held with the Corporation to see if there is an advantage for them in selecting the land and with the USFS to see if obtaining a Special Use Permit, which could require a USFS Environmental Impact Statement, would increase Project implementation time. If there is no reason for Corporation selection, an FERC application should be filed upon completion of the feasibility study by rearranging the material in the feasibility study into license application forma t. For the purpose of developing an implementation schedule and for the other analyses contained in this report, the case in which a FERC license application would be required is used. Design and permits other than FERC could be completed during the licensing period to insure that construction and equipment supply contracts could be awarded as soon as possible after the license is granted. Implementation Schedule An implementation schedule for the Project is shown on Exhibit B-7. If organizational arrangements and the feasi- bility study are begun in the fourth quarter of 1979, the project could be in commercial operation by the beginning of 1984, assuming an FERC license is required • C-V-3 'I 36 .. ,J , .. BA~., .. ,' ..··i~" ....••••• } '1 ., " ''I •• ~ \a ~ 4 Pow~rholJ.se -...., &-..I.LS.R.ZA ENGINEERING COMPANY AUGUST '979 ~ ~ I e"9~ or Esc8/"l'm."f ~ .... C'fl I ~ .... (\I I Remove Rocks 1:15 In'ic3f~d fo Improve Sp/llway(Falls) Outlet '--· ...... f~cf Ft1ce wifh Rock /Jolf.$ ~11" Wir~ Mesh. ~ ~ I ~/ / "'-----Pe n~ tocl< TU"nel enfrance e I1C/03e.r/ in Co"cref~ / II/eroSion {)uri"1 COI1$frucfiofl EXHIBIT C-Z \ "" \ ~. Recommended W. s. EI. lIS Normal H. W. £/. /26.5 ! ~PMF ~LH. W. EI.I15 _ Nofe: For 5ecfiol1:5 8-/J ~ c-c ~t!t! Exhiblf C-,3. Dam SECTION A-A PROFILE. ALONq PENSTOCK. 100 I 200 reef I ALASKA POWER AUTHORITY CATHEDRAL FALLS PROJECT qENERAL PLAN 1 , • 160 15"0 140 130 120 110 100 125 120 1/5 /10 IDS 100 95 Ori.l1iwl ~round 1 1 1 1 1 1 ~ , .0 \ ...... ~ .. .. ' ' .. ,. j." .,' .. fl'" , .' \ \ \ a7 ~ \ ~ p.o. T. Cresf EI. /IS is,oil/way SECTION OF [JAM LOOI<IN'I UPSTREAM !fcale 0 20 40 F .. 8t LI ----1_il __ -.J1 £1. 110 OrtjiNlI CirouM £1. 100 ..... ; ... . SECTION THROU(jH !SPILLWAY Scald 0 4 B Feet 1...1 _L---,-I __ --"I Confinuous Co"c:ret. Em""d",,,,.,t and fSul'l"'rt EI. 1Ir------~Il__-I"? Anchor /3l1rs 6.0' Into ROCK .f 10.0' &C A 10"9 I'en$toc I<. SECTION 8-8 Se./e () 4-e Foet 1...1 ~'--...JI,--_----,I ~ ENGINEERING COf,/FANV . AUGUST 1979 Tun""ISupporf.s 6 'IF 25 ~ 4.0' OC. COnGr .. fll /3ac: I<. Nil '3.0' SECTION c-c 5cal .. 0 1 4- 1 8 Feet 1 I' " Rock ~olt5 4.0' Long tI 4.0' ()C Ala,,! T u""81 (jen~rafor {3 75 /(MI) 30" ? 8uft~rfly V..,/v~ I POWERHOUSE TRAN5VER5E SECTION f -r. rr- 8Fc~t 1 EXHIBIT C-3 5tesl Colu",,, SUI'I'0rt for Crans Pref'"bricat~d fSul'e,.,fruc rur. (12' ~50'x20' Hlfh) Fixed 8lad .. Prop4lltJr TurbirN (527 HI') Possible Future ExpanSion~ 1------- til 0 ~ ~ f-f-r-f-- f-f-t-t"-I ~ ,~-l"'Z£r"ction 84,/ z...t +-t+ 1 / t~ 1'-.1-/ \ I \ I l--' \ 1 I 01 1 ~ I ~ ~ I I I I -L-__ L _____ _ 1 1 i I IH 'iI.0' ~.O' /3.0' 31.5' POWERHOUSE. ,.LAN VIEW 5clllt! 0 4 !J Fnd LI _-'-----1I __ ----'J ALASKA POWER AUTHORITY CATHEDRAL FALLS PROJECT PROJECT 5ECTIONS AND PLAN -M - - ESTIMATE HARZA ENGINEERING COMPANY CHICA.GO. ILLINOIS EXJ1IBIT C-4 P'ojo<' Cathedr at fa lIs II rod r6 Do'. 5ee 1'17 q Po.. I of 4 Po ... Structure Svrt1ooaC:V-J Ccnc~ am PreJ'ec, i Estimated bytfa~d'gha" Checked by ltI!Jn hm I I ITEM QuantIty Unit PrIce Amount No. !~ 1 MOBILlztmOtV ~ 1/7 Z. LAtJD 4 lA~D 'R'Gf..ITS Doo 3 t:ES fJ2. \j 01 R. CLEAk\lJGr ~ 000 4 Dp/f.RSIOtJ 4-cA12c:. OF WATE£. i/Qs 1000 e:; ~~ ~'Tr;~AY J ItJTAkt!. / iD~~ COc 0 J l5'3<1 OOl) r 2C tJ ! CT()~" ,---'=- '7 :po :J1EP. H 0 U SF IZ.~ ~.~ g H fc).·UH) leA L J £1 rc.:-tk":J1 ell 1 F(~UIP 4lJZ 000 q 1(011.D5 AND RKtD&ES 444 O~ 10 TPlWs /--1 ISS/ ON ~9? IroJ -- .s~ }ETDTI+L DI£E6" CDsT 4 17€lP DOC ~TI l)6,EWC! r:: ~ 2~q;. -+ i::..'::';:' ,'!'! -I Iq7 000 1- TDTAl-VI F.F.GT ""'OcT 'I..f ') 5 ~ IDO ~ ENb(UEERI ,J(~ i ADHtU, 2D% ~ ( lit 7 Doc: .f--- ThTf+' Cnt-..}STl2( I r:TI o~J Ct'l...ST 7 I/Oa 000 -, -+- I .j I t -,- I---- I----f--~ ~ I ... ... ESTIMATE HARZA ENGINEERING COMPA.NY CHICA.GO. ILLINOIS £':</-1/811 C-4 --- ') , i Page 2 of -4 Pages StructurelJeia,'Ied P~im Esf _ • R. /'oil I Sft-i Ci7c Dam PrOf Estimated by DaiJadgha V Checked by Allen " I ~I - Unit PrIce I No. ITEM QuaMIty Amount ~-- I M&1LI2ItT! On) J...S blo~~ I--L I ~ ----~--,---------i ~_~+L4N-D_lil'tUDJ;.~1 (yHT:5 -iLRC::&::fYDi r , b Arc ISoc -~ __ L~'F6~e~<;p .d (.amp C; f'fe 3 Ac /000 =jJcm ..... . .., .3 ~r·c",dlr:i.J.J .«-+, L ' I l-e lOOO I I '000 __ .,_~_ ~ "",t:..-L. __ ::...!....,J i I \...e<' < 'A ""-, . _4 Ac J 000 4 tJ~(j ---l-L1~,;-~a d .-.;: -=r=-'------.5 'J~"fuT3; J1 ~ ---- - ~ i?E5E12iP t R CLfPF~ /J)G-5 lie 7500 51 90 - ---r-- Dl'lff~SI QtJ J CAKE -4 of ~ATEE .. L5 (9S Ocu ----_. -- .--- ~j~~ILI..\lJIl'i 41NTAk:F _ .1,-1.-~/;;.. E~c?JlLafj'on 2Ro cy 48 13 44( --j'z. Comm on Exc?Jva"fi"n GaD CY 7 I 1 ,.so _, __ ,3 DrilUr1~.t6to~t;nq ~Q~odatiQn 150 Lf" .3~ I~ aJo 1 + '..f ' 1-4 so Cy goo ~s 1000 '--.-i~ (O'v-:r~~~ . 7tS~ I-J"' ~oncrE Ie; s rr\)~+\J r a I 35 Cy 35"0 Il 250 ,.,," ____ ·f2_~Nen t 5goocvr 14./0 81 ~ RI '+' r-~ f l7.b50 LBS LllQ .J9.. .ill !-__ _7 __ .s~t:::L~~ln~ ::;_~e .. ' __ , __ +~.br.alrL3~ 0 lei 5 '2 '2S LF s4 I, ~ 1---t q fu~k 6-:a-E EyYlbed. Fa,.1! LS ~oo Q9Q ,~. , j.t. • 3000 CY IZ~ ~ _.,, __ J9._'~Xk:;)nne{ EACdV~1i on ~ L ~brO-rriJ I Ol~ Iq~ ~----~-\ ----.... -~....--..-.. --, L \ -I ---'---~'---"--- ----t---.... - I -----+-_._----_._------ L---t------------ ESTIMATE BARZA ENGINEERING COMPANY CHICAGO. ILLINOIS ~ ~-."'Ioct Cafhedrol Fa ! ~ ~ Hyd~() Dot. Sc p 19 7 q R ,:,ag• 3 01 ~ Pag., Structure Detat led lteflm. [51 (CO(1C Dan1 ) Estimated byDabadghai/checked by,iJtJn ... - ,.., ... .... ' .. hm No. ITEM Unit PrIce 1--~-------------------------4----------1-----1--------6 I WATEK/";OAlfJ U c TOR Ex c av 8 t/on _________ -1--__ -=-1..:....;0 O~G L-'---I __ ..w..= eS--l ___ I_""'-'-F ~g;~\)C CDii c rete ISO cy ~25" '/2'31S0 I b I?einforc,'no Steel R4() L~ 30 11425 LBS B,Eo I--~-------------------------~-------r----·r---I·--~ 7 POWfRHou.s£ .1 Rock fxcavait'on 7(; Cy 4~ t 5 Cemen t } ISfo CvJT 14.10 Z Z.()~ __ b Kel'n+nrcin.o .:s-fee.T 20()o LBs 1,/0 2 ZOt II 7 str()cturljfJSt~el 1000 SJ=:. 10 IOlJOO . e Pre:fabr--t'ca.ted pJdo J2'X50' =w~sr= 0Do 51= 25" J5 COc SL)b1b+a J r/ZSI3~!: --'~~~~~----------r--------+-----r-~~~l I--~------------------------~-------+----T---I--~ :=-~+-j -=-.-----~--.----~-------------~--~--I-+-----------~-+-------t-I~-_t-I--I - ... - ' .... " ESTIMATE BAUZA ENGINEERING COMPANY CHIC ..... GO. ILLINOIS ExHIEIT c-4 p'oJo<t_Cdherirai Falls ro 0-Sep /q79 Pag •• 4 of 4 .. Pogo, StructureDefaded H:e/lrn,st(Conc Dartl) Estimated byr!o~ljdifbav Checked by i!1en } ...,; - hen ITEM QVCIftIIty UnftPrfce Amount No. . _1_ ~ IMFC~N(cf+,LJ-E.UEC1T2IC~L. EQUIP. ,I Turbinp Governor ~ \ -.2 6ene.~'fos [xci fe,... - )0. 2Unit.s /bOJJOc l320 DDr:. L3 Tt 'AOe, hr-n ;Qr' ,4 ) ... Usc: l:let:.r £~J uip. J , S' c 't' . \'" --L. ~\J1.Llc ri a e ~ r . ~ ~ ._ Lob 'Bu \~r-hhiJ t;e Cr?-)ne 7tSrD(} LCS -1 ~tal ktD2 Ooc -,---1-----f--- q 1(oAbS ANlJ Bf?I15r;£s :tLJ~n:2-b 2J n I!flj en'T P t"lB d Ot~ MI i74fJ.l)(j 0 'Md ~OO ---I --",---~ /0 ~ANSMISSjDIJ Cf !AT 55200 4q~ I Sec I'" :-X I rill., ~'" Slno{e C1rcut'f , J -:. I ~.' . f~ CQQ.c..( ;, ~ 1= f---'J _._,--«--.--.-~,--. .. -~.......,.~-..--.. I--- _ .. -,----. "' __ " ___ .~'_«-"U_"""""~._~_.~ _ ,----,~ ,.-----,-~-- f------1----' -I--- - -,""'.. ---.. .. ----.,.,.--~,-I --+ - i I--- f--- ----i---,-" r--- , .. , ' .. ... . ., .... _. ... .... ,,.; .... EXHIBIT C-'5 ~1uH! + 30fi :<1 ,..,. EX#Ii3lr C-5 ~) ee.f 4 of' 4. r t-- :z ,.. r,j . Iii , t1LCf ~ I 0 ,Cl (> I , + - , I I I I t -++-+-+--t-1--+-1c--1 ++++-++-++-++--t----+t-t--t-+-++-t--- c---H-+-+++-t--t f--t-+-+--+-+-+-+-+-+--+-+-+-+ ~ i i t .i l :; CAYr~F"DRAL FALLS PROJECT HYDRO cnST OF ~C~EY= .020 !NFLATI0N RATE: .OIJO FuEL ESCALATIOl'< f.lA TE:; .. 020 OISCOUNT RATE= .OBO REFERE"ICF.: DATE = J HIllARY IQ50 ALL COSTS PJ S 1000 FIXED tJ + " F'UEL EI'<ERGY COST OF CUMULATIvE PRESENT CUMULATIVE ~E::I.R COSTS COSTS COST r~TAL GEI'<ER A TED E"'ERGY TOTAL 1oo0l<TI1 p,W. HwH C E " T S / K W 11 \91>./j 268. 273. 'S II \ • Pd5. 2'1.8 5111, 368. !loR. , cpu:; 265. 28.3. S 51. 1872. 2'1,5 1092. 3117, 715, lGSb 26< 2<:;<;. <.;63. l Q 32. 29. 1 1655. 328, 10 1l/ol, \q~7 2b8. 301. s7S, 1993. <' p,. 8 2?2Q. 310, 13SLA, lQ~~ 208. 3\'1. Sil7. 2057. 2'.5 28!6. 2'1<.1, 1648. 1'1l>.q 203. 332. 6 0 0. 2122. 28.3 3416. 278. lQ25. 19C10 2/'111. 3:15. b t 3 • 21 9 0, 28.0 4029. 263, 2188, 1 qQ I 209. 3,'1. 6 2 7, 2260. 27.7 4655. 2U9, 2IJ 37, 1'1'12 26'3. 373. b /J 1 • 2332. 27.5 5296. 236. 2073, 19'13 208. 31''1, 1,'56. 2 .. 06. 27.3 5952. 223. 2a96. 1 '19 u 2t>Fl. 403. 6 7 1 • 2!1iJ3. 27.0 ob23, 212, 3108, tq~5 20'3. u20. h 8 8. 2527, 27.2 7 .s 11 • 201 , 3308, 1996 2"~, (;3b. 7°4. 2573 • 27.IJ bOt5. 1 <11) • 3(!QQ, 19n 268. 1I5/J, 722, 2619. 27.1, 8737. 1 d 1 • 3679, !t)91\ 268. /J72. 7a O, 2b69. 27.7 9477. ! 7 1 • 38 ~ 1 • \'")Qq 2 b 8'. UClt. 7 5 <1. 2714. 28,0 10~36. Ib3, ,,01" • ZArlO 268. 510. 7 7 8. 27b/J, 28.2 1 I 0 1 !j • ISS, tJlbS. ?OOl 2n8. 531. ,qq. 21313. 28.U 11813. 1 (j 7, IJ315. 20~2 208, 552. p20, 28b~. 28.6 12633. 1 a 0 • 41 .. 55. 2n03 268. 574. RaZ, 2"116, 28.9 1347'~. 1 .5 3. lIses. ?1'I0Q 26B. SQ7. pbS, 2Q68. 29.1 1i.J3!.l\, 126, "71 a • ('00S 268, 62\ • I\i3Q, 3021. 2'1.4 1"230. 120, 4831.1. 2:)G6 265. 6 1J 6. q III • 3076. 29.7 lo1u3, 1 I <I , "9IJ9. 20n7 208, 672. Q4 0. 3132. 30.0 17083. 109. 5058. 21'108 268. 09Q, Q07. 3188. 30.3 10050. 10/J , 5101 • 20n9 268. 721. '1 9 5. 32/J6. 30.& IQO/J4. qq, ':1200. 2010 201l~ 7'56. In24. 330a, 31 ,0 200b8. qIJ. 535a. 20 It 268. 7!lb. 11'15". 336/J. 31,3 21122, 90. 5/J!llJ. 2,1 \ 2 2bo. 8: 7. 10 8 5. 3424. 31 .7 22207. 86. 5530. n13 2oe. 8S0. I \ ! fl • 3lJ86, 32. I 23325. 82, 5611 • 2 J 11: 206, 88U, ItS.?, 35LJc;. 32.5 2/J~77, 78, 568q. 21'1S 268. <l1'1. 1,87. 3612. 32.'1 25664. 7tJ. 576/J. 2016 208. 956. 1;>2iJ. 3678 • 33.3 26888. 71 • 5835. <'017 268. '1QU. 1;.62, 3678. 34.3 211150. b8. 5902. 2\"'1 t ~ 20S: 10';4. I~02, 3h78, 35.1J 2'11.152. 65, 5'167. ~ ~ 2 \' 1 <;i 208, 10 7'5. 13":;' 3078. 31).5 307'16, b2. 6rJ2Q. 2~?O 268. IlP. 1 ~ til:> • 3678. 37.7 32182, 59, 6088. ('Dill 2b8. l1b3. lu31. 3678. 38.9 33614, 5&. 6145. ~ ~ 2C ?2 268. I 2 \ 0 • 1 ~ 7 1\ • 3678. '10.2 350QI, 54. b199, rb ;> PI 21,11. 1<'<;8. 10;26. 307~. Iq .5 36bl1, 52, b250, "\.. t\), 2)?(J 268. 13(15. 1<;7(" 3676. 112,q 381'1/J, (j"l, b30C. ""'" ?(12~ ?bfi. ! 30 j • 1..,2<;. 1078. 44.3 39823. U1, 63a7. t\) 'i 2!')?6 208. Ill! S. 16 8 3. 3071\ • 1.:5.8 IJ150b. U5, 03'12. 20n 2b8: 1 /.j 72. 17 Ii 0, 3678. 47.3 1.132/J5. 1.13. b435. ~ C) 202"1 268. t '5 H. l,qQ, 3b18, CJ8.'1 UC,OLlU Q 1.11 • b/J77. ~ I 20?"I 26&, 15'12. IpoO, 3678. 50.b /Joq"lJ. (JO. 6516. ~ '2 (I -;.) 268. 16'56. ! '124. 3078. 52.3 1.1852'>. 38. b5S4. \J) 2031 208, \ 722. 1990, 3b78, 5<.1.1 SOt17, 36, b5'11 • 2032 268, 17'11. 20 5 "1. 36 78. 5b,O 5287b~ 35, bb2b. 2:J:q 260. 18!>2. 2\30, 3&78, 57.'1 5500b. 33, b65'1, l--tARZA fNGINEERING COMPANY CA1~fURAL FALLS p~OJECT HVDRO cnST OF MnNEv: .050 INFLATION RATE~ .040 FUEL ESCALATIO~ RATE: REFERE~cr rATE ~ J'~UAPV }QR0 IQAlJ 1'.;; 5 . ; 9"6 \Q~7 Igo.1~ IQA'l t~qo I qq I Iqq2 \qq, \ q q 'i 1'<0" 1'10,., t'lel? \~qp. Iq'lq ?on'\ 2;>!l! 2002 201'13 2,J (1 /.j 2~05 2n06 2!JCl7 20"'''' 200'l 2010 2:J \ I 2012 2013 20\1.1 2015 2:lJ6 2 'J I 7 2018 20\" 2n?1) 2('21 2022 2Cl23 2 ')211 2(125 2026 2027 ?n?11 2'12'l 2030 2031 2032 2033 ryx[!) Cusr~ /J6B. 4b8, .:Jb8. LI. ~ r~_ l.l " ~ • 4nB. lJ"d. t;b8. /,;106. /Jon. .. cd. 1.16i1. 1Jt>~. /;6B. 468. /Jbl',. 1,10 Il • t;!>o, llod. ,,-,,6. ""fl. 1J6B. 468, 1.160. 408. /Jo8. 1.165. '/Jb8. AbB. lI63. lI68~ 4~R: /;bl\. 468. 4/)8, <.168. 1;68. Llb8. (J6B. 468. 468. /JoB. 408. 4b8~ 468. /168. Lib8. .:Jb8. ll08. 465. COSTS COST TnTAL 273. 283. 2'1S • 3,1 -, • 31 q. 332. 31<'5. 3SQ, 373. 36~. 4"3. I< 2 ,J • /131,. L1SIJ. ll72, II C; I • 510. 531 • 552. 574. 5q7. b 2 I • 6/16. 672. 69q. 727. 150. 786. 8 I 1. 850. 884. Q 1'1. '156. q'lLi. 1034. 1(1115. I 111' • 1 16.3. 121 0 • 1258. 1308. 1361. 1415. 11.172 • 1531 • 15 q 2. 16'50. 1122 • l1Q I. 18b2. 71.11 • 751. 703. .,75. ,H7. flOO. I'd:; • R27. I' iJ 1 • 1<56. p, 7 1 • 1\88. <:lOll. .. 22. qilO. C/5'l. q78. qqq. 1('l20. 1{\42. In65. 1(18'l. I I \ (j • 11 40 • 1 167. 11 9 5. 1?21J. 17 5 1.1. J2 8 5. 1,1fI. 1:\ 52.' 13 8 7. 142£1. 14 6 2. 15 0 2. 15 4 3. 1<;86. 1 h 31 • 1,,78. 11 2 6. 1776. lp2C/. lA1l3. 1"11.10. I'lCiQ. 2n60. 21 2 /1. 2\90. Z25~. 2130. ALL COSTS I~ $ 1000 EN~RGy CUST OF GE~ERATED ~NERGV M.H C~NTS/KWH I " ! 5 , 1872. 11132. 1'1<)3. 2057. 2122. 2190. 2200. 2332. 2 1l 00. 21.1e3. 2'527. 2573 • 261C/. 2bb9. 2114. 2761.1. 2813. 2il6U. 2 'l 16. 2'h,8. :; 0 2 I. 3076. 3132. 31138. 32'l0. 3304. 3304. 31.12U. 3486. 35l19. 3612. 3678. 3618. 3678. 3018. 3078. 3678. 3b18. 3678. H 18. 3678. 3618. 3678. 3678. 3b 78. 3678. 3678. 3678. 3078. 40.B 4 C. I 39.5 3il.q 38.3 37.7 37.1 36.6 36.1 3'lt6 3';.1 35.1 35.1 35.2 35.2 35.3 35.1.1 35.'5 35.6 35.1 35.'l 5:'.0 3b.2 36,1.1 36.6 36.8 37.0 37.3 37.5 37.8 38.1 38.4 38.7 3q.8 1.10.8 1.12.0 1.13.1 41.1.3 1.15.6 U6.'l 1.18.3 4'l.7 51.2 52.7 '51.1.3 56.0 57.1 59.5 61.4 b3.U CUHuLATIvE TOTAL 141 • 14'12. 2255. 302'<, 38\6. 4616. 5<.12'1, 1.>255, iC96. 79':J2. 5b23. 9711. 10615. 11537. 12417. 134510. 1,,41'1. 15411. 16433. l1Ll75. 105Ul. 1 9 b30. 2071.13. 21!J83. 23050. 2421<4. 25(;68. 2b122. 2£\007. 2'1325. 30b71. 32064. 33488. 34'150. 361.152. 31QQo. 39')112. /I 1 2 1 /I • 428'11. 1I4617. /l63C/U. 1I8223. 5010b. 52045. 5U044. 50104. 58226. 60417. 62611:1. 65006. DISCOUNT R.T~= .080 ~f~ESE~H ... ORTH SOil. 47<1. Ll1<5. " \ 13 • 394. 370. 3(;9. 328, 30 q • 2 q 1. 275. 25'1. 2iJ4. 231. 21e. 20/). 1'1 t.I • 1 e 1.1 • 11 u • 16(1. ISb. I!; 7 • 13Q • 132. 125. 11'1. 113. 107. to 1. C/b. 91 • 87. 83. 1'1. 75. 71. 08. 01.1. 01 • 58. 56. 53. 51. '18. 1I6. 4U. 42. 1.10. 38. H. SOU. ~78. !~23. 1 !' 1.1 1 • 2235. 2605. 2'l5/,j. 3252. 3591 • 3633. 41'=>7. U"16. I<b61. 48'11 • 510'1. ~ 315. ~'>O'l. 56'13. 5807. 6031. b187. 633(1. 6413. 0605, 613h b64q. 0962. 106'l. 1110, 72&&. 7358. 7iJ1I5. 7527. 7606. 7680. 7752. 781'1. 7884. 7Q1l5. 8003. 805q. 8112. 8162. 821t. 8257. 830 1. 631.13. 8383. 8421. 8'151. ENGINEER I";" COMPANY I CATi-'fDRAL FALLS PROJECT H"DRO crST OF Mo"E"= .1170 tNFLATION RA 1[= .0'10 FIJEL ESCALATION RATE: .020 DISCOUNT RA Tf:.: .080 REFERENCF DATE = JA"LJAR'I 1<)80 ALL COSTS IN $ 1000 FpEr'l 0+'" FUEL E"ERGY COST OF CUMULA T 1 VE PRESENT CUI'IULHlvE 'IEAQ COSTS COSTS COST TnTAL GENf-RATED E f; ERG Y TOTAL WORTH p.w. M ... H CENTS/KI'IH IQI'(J b2b. 273. 8 9 Q. 1815. 49.5 899. b12. b12. I Q;I S b20. 283. qOq. 1872. 48.b 1803. 573. 1185. 1986 b2b. 295. Q21. lq3?. '17.7 2729. 537. 1722. I (HI 7 b2b. 307. 1)33. 1993. Llo.s 3601. 50'1. 222b. IQIIIl b21>. 31Q. q U5. 2057. u5.Q 6400b. '173. 20911. lqi'\Q 020. B2. 958. 2122. 45.1 550'1. uua. 31u2. IQCiO b2b. 3£15. Q71. 2190. UU.3 0535. alb. 3558. 1 9Q I 626. 3C;Q. Q65. 2260. u3.b 7519. 391. 394Q. I'1Q2 #>21:>. 373. 9 4 q. 2332. U2.B 8518. 3b7. 64317. I QQ 3 b20. 368. 1 n 1 tl • 2 UOb. u2.1 '1532. 3u5. Ubb2. IQ9u 02b. Ll03. In2Q. 2 Un 3. tl 1 .5 105bl. 325. U'18b. 10q<; b2b. /J20. In"o. 2527. tl1.4 lle07. 305. S?92. IqQb 02b. /J3b. IOb2. 2<;73 • Lll • 3 12bb9. 287. 5579. 19Q7 621t. /J5u. 1 n 80. 2b19. u 1 .2 137£19, 270. 5eu9. 199B b20. 412. 10 Q A. 2009. tl I 'i 1 l U8£;7. 25'1. bl03. IQ<1<1 020. £I <1 \ • 1 \ 1 7 • 271U. Ul.~ 15'<b£l. 2uO. 0343. 21?t"IO b2O. 510. 11 36. 2704. 41.1 17100. 22b. b 5 b 9._ 2001 ('2b. 531. 11 5'T • 2813. 4 r. 1 18257. 213. b781. 2e02 020. 5132. 11 7 8. 28blJ. 'I t • 1 19U 35. 201. b982. 2(103 b2()~ 571J. 12 0 0. 2qlb. 41 .2 20e35. 189. 7171. 200!! b2b. 5"17. 12':3. 2 9b 8. Lll .2 21059. 1 7'1. 7350. 2 (1I~ 5 b2b. b21. 1;?/J7. 3021. iI \ .3 2310b. 169. 7519. 20116 620. bue. 1('72. 30 7b. 64 1 .:3 2 u 377. 159. 7b78. 2007 o2b. 072. 12 9 8. 3132. a 1 .4 251:75. 150. 7828. 2008 02b. oQq. 13 2 '5. 3188. U 1.5 27000. l U2. 7Ho. 2009 620. 727. 13 5 3. 32 U &. .. 1 .7 28352. 13u. 1l105. 20ln &20: 756. 13 8 2. 330tl. U 1.8 2 9 734. 127. 8232. 201 1 62b. 78b. 1/J12. 33b4. 112.0 31146. 120. 8352. 2012 b2b. 817. IlJtl3. 342U. U2.2 32589. 11 4 • 8ubb. 2013 02b. 850. I1J76. 31l8&. 1;2.3 3 1J 065. 108. 8S7a. 20ltl 626~ 881J. 1'5 1 0 • 35<19. £:2.5 35':)75. 102. 8b7&. ?a1S 62/). q19. l"u5. 3b12. 42.8 37120. 97. 8773. 201b b20. qS6. 15 8 2. 3b78. 43.0 36702. q2. 8804. 201'7 02b. QQ4. 16 2 0. 3078. /J/J.l 40322. 87. 8951. 20lR 620: 103a. Ib o O. 3e78. tl5.1 1J1982. 83. 9011.1. ~f1l 2019 020. 1075. 1701 • 3b78. 4b.3 1l3084. 78. 9112. 2020 b20. 111 f!.. 17 U a • 3078. tl7,tJ uSLl2R. 711. 9187. 2021 b2b. Ilb3. 1'8Q. 3b78. 48.0 11721/1. 71 • 9257. ~~ 2022 b2b. I 2 I 0 • 1/136. 3b78. 4'1.9 11'1053. b7. 93211. 2023 020: 12'5/l. lp81J. 3078. 51 .2 50937. bU. Q38/l. ~, 21'124 020. 1308. \Q3u. 3078. 52.6 S2872. bl. 91J1J9. Ol ?C?5 b2b. 136 I • 1<187. ", b 78. 511.0 5'<858. 58. 9500. ~ ........ 2r· ;?b b2b. 1 q S. 2n u l. 3078. . 5S. 5 5b900. 55. 9501. '" ?r,27 62b. 1412. 2oqP.. 3078. 57.0 58997. 52. 9613. ~() 20211 020. 153\ • 2\57. 3078. 58.b 011SIJ. SO. 9b03. ~I 2n2Q o2/). ls 0 2. 2(,18. 3678. bO.3 &3372. 47. tH 1 O. 2030 02/)~ lb~6. 22 8 2. 3b78. 02.0 b56511. 1l5. 9755. \.0 ~ 2('131 020. 1722. 23'18. 3078. b3.8 b8001. il3. 97 9 8. 2032 026. 17 q I. 2/J17. 3078. b5.7 70 4 18. III • QaH. 20 'B b20. 1862. 21188. 3678. 67.7 72900. 39. 9a78, l-IARZA ENGINEERING COMPANY , CATHEDRAL FALLS PROJE.CT HYDRO COST OF '~(1"F.:v: .0'10 I"FLATlON RATE= .0'10 FUEL ESC:'LATION RATC.: .020 DISCOUNT RATt.: ,080 >lEF"ERENCE r")ATE : JA.,UARV lQBO ALL COSTS IN :0 1000 FIXE.r' 0 ..... FuEL E"E.RGY COST OF CUMULATIvE PRESENT CUMULATIvE YE AR COSTS COSTS C,OST TOTAL GE."'E~A'T'ED E"'ERGY TOTAL ... ORTf-i p.' \lot • /'."H CE"TS/K ... H !qf\/J 797. 273. 1 n 70. I 6 ! 5. 58.'1 1070. 728. 728. 1'/ II 5 7Q7. 2'3:3. 1(,80. 1872. 57.7 2150. 081 • 1140'1. IQ"6 7 9 7. 2'1'5. In '1 2. 1'132. 50.5 32142. 037. 20 4 0. I'H\7 H7. 307. 1 I 014 • 199 3. 55.14 1.13145. 590. 20142. IClIlA 797. 31 ~. 1 I 1 Q • 2057. 5'1.2 51.1~d • 558. 3200. 19PQ 7'17. 332. 1 ,2 q. 2122. 53.2 6590. 523. 37 2:S. 19'10 7'17. 3115. 1 , 14 2. 21'10. 52.1 77:s2. 1490. 4211. I Q'1, 7'17. 35Q. 11 5 6. 2200. 51 • 1 8887. '15'1. '1672. 1'1'1" 7'H. 173. 1 I 70 • 2332. 50.2 10057. '1:)0. 5102. I'1 Q 3 797. 3t\8. I 185. 2(100. 1.1'1.2 112IJ2. '103. 5505. IqQ~ 7 q 7. 4rl3. 1?00. 2'183. '18.3 12"'12. 378. 588u. IqQS 7'17. '120. 1 ? 17. 2527 • IJ 8.1 13b59. 355. b23'1. IqQb 7Q7. 1130. 1231 • 2573 • '17.'1 1'18 9 2. 333. 0572. IQQ7 7'17. 1.151J. I? 51 • 20 1,!il. '1 1.8 1b1'13. 313. 088S. 10 '18 797. '172. l?b'1. 206'1. 'I • ') 17412. 2'1'1. 71H. 10Qq 7'17. 14 91 • 12 s e. 271'1, 147.5 18700. 270. 71.155. 2 (\(\ 0 797. 510. 1 J 07. 27t>1J-. 47.3 20007. 2bO. 771S. 2001 7 Q7. 531. 1328. 261.3. '~ '17.2 21335. 2'1". 7QS9. It_ 2002 797. 552. 11'19. 2804. '17.1 22081.1. 230. 8189. 21ln'3 7q7~ 57'1. 1 '3 7 I • 2 9 1&. '17.0 2'1055. 210. 8'10S. <,onIJ 7 q 7. 5 Q7. 13 9 '1. 2 9 08. '17.0 251.150. 20'1. 8609. 2005 7Q7. 621. III 1 8. 3021 • '10.9 26868. 192. 8801. 2006 7Q7. 6 t.b. 11.1 '13 • 3076. '10.9 28310. 181 • 8'181. 2n r17 7'17. b72. Il.Ib9. 3132. 'Ib.q 2'nH. 170. '1152. <'CIlA 797. 699. 11196. 3188. '10.9 31275. 1 b 1 • 9312. 201lQ 7q7. ;27. 1<;2'1. 324b. I.Ib.'1 32798. 151 • 9 11 03. .?~IO 797. ;'5b. lc;5:S. 3301J • 147.0 311351. l1J3. 960b. 21) 1 I 7Q7. 7Rb. 1<;83. 336'1. '17 • 1 35 9 3(1. 135. 97'11. 2C 12 7Q7, 8 I 7 • 1 II IIJ • 3'12'1. 47. 1 37541\. 127. 9809. 2013 7 Q7, 850. I b 14 7. 3'18b. '17.2 3'11Q5. 120. 9<;89. 2011J 797, Si\q. 1;,81. '35 4 9. '17.'1 '10876. 11'1 • 10102. 2010; 797, Q19. 17 I 6. 3b12. '17.5 1J25q2. 107. 10210. ;>Olb '(Q7. 956. 17 5 3. 3b78. /J7.7 1.11.131.15. 102. 10312. 2017 797. 99'1. 17 9 1. 3b78. lIB,7 1.10130. 90. 101l08. 2011'1 7<l7. 1034. 1A31. 3678. '19.8 1I79b7. 91 • 101J9'1. (J)~ ;>019 7Q7. 1075. 11\72. 3678. 50.9 '198 /.0. 86. 10'385. 2020 797. 111 R. I Q 15. 3678. 52.1 51755. 82. 10&07. ~~ 2(121 797, l1b3. lqoO. 3078. 53.3 5371&. 77. 107'la. ~ ~ 20;12 7Q7. 1210. 2n07. 3078. 5'1.& 55722. 13. 10811. 2:)'? '3 7Q"t. 12S~. 2055. 3678. 55.9 57777. 70. 10887. 'i--tb 20<''1 7'17. 130" • 21°5. 3t78. 57.2 5<1883. bo. !OQ53. ....... 2025 7<:/7. 130 I • 21 5 8. to HI. 58.7 020'10. 03. 11015. e.,. "i 2:)2b 7Q7~ III , '5 • 2;112. 3&76. &0.1 b IJ 253. 59. 11075. 2027 7q7. IIH2. 22 0 9. 3078, 01.7 00521. 5&. 11131. ~ <) <'O;lA 797. 15:3 I • 23 28 • 3b78. -&3.3 b88'1'1. 5'1, 11185. ~ ?:) 29 7<:/7. l:.q2. 23 89 • 3b78. b5.0 712H. 51 • 11236. I 20~O 797. 1056. 21453. 3078. 60.7 730'11. a8. 1128'1. \..0 ~ 2e31 7'17. 1122. 2519. 3&78. &8.S 70209. /Jo. 11 Ho. 20'32 797. 1791 • 25 8 8. 3678. 70.U 787Q7. lJa, 1137a. 2/jH 797. 18b2. 26 59 • 3078. 72.3 811156. '12. 11'116, I-IARZA ENGINHIlING COMPANY i. t 1 t , i. l i-t l 1 , l i l i CATf.'FDRAL ~ALL5 PROJECT nIEStL At..HR,',ATIItE CeST OF "O',EY;: .(120 y"FLATlnN R"H::: .0LlO FuEL ESCALATIOr-. RATE:; .02Q DlSCCUNT RA TE= .OBO REO:ERENCE rHE = J'~UARV !'IBO ALL COSTS PI $ 1 000 f'" !XEo a ... j..~ flJ E L ENERGy COST SF CUHLJL!<lIV£ PR£SE"T CUMULH!VE 'reAR tOSTS COSTS rosr Yo'fAL GE I,!:. R A TEO EI;fRGY TOTAL "'ORTH FleW. ~"'H t:ENTS/i(",H 19"'1.1 0, 204. ~31. 1l35. 1815. 2i.l.O 1l3S. 290, 296. 1 'HIS " v. 2 \.~, ?5? , /.)1:15. \872. 2l!.8 900. 293. 58q. i'll'/> O. 22\ , '76. IJ Q7. 1932, 25.7 1397. 2qO. 87G, 19?7 o~ 230. ~O~, 5~2, jQ93. 26.7 :'12<1. 2e7, 116b, 1<1;>'8 O. 23<:), "30. 5 6q • 2057, 27.7 2~98. 28'5. llJ 5 1 , Iq~<:) O. 2iJ9. <'6 ! , f) 10 • 2122. 28.7 :3 I 08. 282. 1734, ,<lQa O. 25~. ~j q5. b5IJ, 2! '10, 29.8 3761. 280, 2 (j 1 ~ , lQClI O. 269. 1J32, "7 a 1 • 22~O. 3 I ,0 ilIJb2, 278. 22<12, IqCl2 O. 280. jJ 73, .,52. 2332. 32.3 5215. 277. 2509, lqQ3 O. 2Cl \ • t; ! 7. (\JfI. 21.l0b. :53,b b022, 275. 284£1. II"lQa O. 303. <;1>5. p.op., 241:13 • 35,0 08ClO. 27IJ. 31 17, Iqqs O. 31S. 1'\ 0, '125, 2~27, 3b.!;> 7815, 270. 3387, 14<:b q~ 327. 1:-56 , q</~, 2'573 , 38,6 8809. 269. 365b. IQCl7 9. 3 1l 1). 71 0, I (j b 0, 2b19. (1).5 9869. 265, 3921, I()<;B 9. 354, '67, 11 30. 2bb9. 42,3 IOQ99. 262. 418) • IQQCl 9. 36B, 1127, 12 0 4. 2714. 4L1,4 12203, 256. 44111. 2"1'10 Q. 3e3. IIQ3. ! ,f) 4. 27b4, 40,S 13487, 255. Llb'17. 2('1(11 q: 398. 963. 13 7 0, 2813. 48,7 14857. 252. Lllf41:1. 2no:? Q. 4 1 ~ , 11\31:1, 11J02. 28b4. 51.1 1032~. 2(JI:I. 5198, 2003 9. 4310 1122, 15 b 1 , 21:11b, 53,5 17881. 21l6. 5(j4L1. 2004 1:1: 4a8. 1;>10. 16 6 7, 21:1b8. Sb,2 1 9 <;'48. 2L13. 5b87, 200C; Q. lib/:). t'Ob. 17 B 0, 3021 • 58.1:1 21328. 241. 51:128. :? O!16 q. 41\4, tU09, 19°3, 3076. 61, q 232 ~ I. 238, 6166, ?I)07 9. SOL:. 1 C; 21. 21")3L1. 313;>. 6 a ,9 2':1265. 236. b1l02. 20118 9. 521J. 1 ,.. 41 , 21 7a • 3188. 68,2 27IJ39, 233, 6635, 2COQ Cl. 545. 1771. 2325. 324b, 71 .6 2'076L1. 231. 6866. 201 () 9. 567, I q I I • 2lJ87. 330Ll, 75.3 32250, 229. 7095, ? 0 I t 9. 58G, 2n62, 2/,61. 33/;>4. 79,1 34911. 227. 732~. 2012 9. e 13. 2;:>25. ZA U7, 31J2a. 83,1 :37758. 225. 7546. 2013 <1~ 1'>37. 2lJ O! , 30"8, :S~8b, 87.1l 40800, 223. 77b'-l. 2'1111 q. otl3. 2<; <1 I, 3<>03. 35:J9. 92.0 IJ1l0bl:l. 221. 7<1'10. 2015 Q. 61\<1, 27'10, 3119". 3012. 91,.7 107503, 219, 8208. 2016 I 1 : 717, 3 n 18 , 37 1l 6. 3b 78, 101. A 51309. 217. elJ2b. ZOi7 11 : 71J /:,. 31<1<1, 3955, 36 1 8, 107.5 552b41. 212. 8b38. 201~ I 1 • 77/:,. 3:; 91 • IJ 177, 3078. 113.b 5<1 4a l. 208. 88'16. 2;) 1 q 1 1 • 807. 3C;Q4, 11412. 3078. 111:1.1:1 b3853, 203, 9041:1, 2!'J 2') 1 1 • 83<:, 31110, /J6 5 9. 3678. 126.7 08':112. 199, <12'17. ~~ 20'1 1 1 ~ B72. IJn313, IJq22. :s078. 133,8 73L134. lClIJ. 911L12. 20;12 I I • 1:107, 1J2 80, 51'lQ, 3078. l L1 1.3 78632, 190, '1632. ~ ~. ~O23 1 I • 944, LI<;37 , '51J<12. 3078, ILl9.3 84121l, leb, 9P, I 7, Z:J2!J I I ! Cl 81 • IJAnCl. 51\02, 31:78, 157,7 8 9 926. 182, 91:19<1. 'i..tl) ~ 'l2S 1 l • 1021. 5<,98, 0\30. 3b78, lbo,7 9605b. 178. ,0177. "'-;>"~ ?6 1 1 • ! 001 • 5/10 C • 6a 7 6, 3b78. 176,1 102532. 174. 103'>1. Q\ 'i 2027 1 I • 1 I () 4 , 57;?S. 61\43. 3678. 186.1 10 9 375, 170. lJ521. 2025 t I ! lilia, 6!)72. 7231 • 3678, lqb.o 110bOb. 107. IOb88. Of) 2(12Cl It. I I q I •• 0036. 7b 4 1, 3678. 207.8 12 L1 247, 103. 10850. ~, 2030 I I • 12:.J2. 61>22, 81\75. 3b78. 219.5 132322. 159. 11010. 20:;1 1 I • 12Ql, 7'32. 8<;311. 3678. 232.0 IlJoeSb, 150. 1116b. \0 0\ 2032 1 I • 13£1.3 • 7,..66, q1)20. 3&78, 21.jS.2 14 9 07b, 153. IlliG, 2~H 11 : IH7. "126. 9s33. 3678. 251f.? 159409. 1,,9. 111l611, I-IARZA eNGINEERING COMPANY 1 , :l Ii i l • 6. i J i i. .. Ii I I .. i t. CATHEDRAL FALLS P>lOJE.CT oIESEL ALTEi<",ArIItE CC'lST OF "'oNEY: .0'50 l"FLAytON FlA TE= .040 ~ UEL ESCALATIO~ RATE: .020 OISCOU~n RATE: .0110 RE~ERENCE OATE : JANUARY 1980 ALL COSTS IN $ 1000 FIXEI'l 0+ ~ FliEL ENERGY COST OF CUMULATIVE PREHNT CUMULATIVE YE AR COSTS COSTS r05T TnTAL GENERA TEO HIE RG 'I' TOTAL WORTH p.W. M ..... CENTS/K .. H l'1lCIlJ a ~ 201J: ;)31. /J3C;. 1815. 2'1.0 435. 2Qo. 296. \'160; O. 213. ,52. 4b5. 1872. 2i1.S QOO. 2<n. 58'1. IQ~6 O. 221. ;>7b. /j97, ICl32. 25.7 1 H7. 2C10. 879. 1Q37 0, 230. ~o2. ,;32. l C1 Q3. 2b.7 192'1. 287, 11 (,b. 1'188 O. 2H. '00. .:;6'1. 2057. 27.7 24'18. 265, 1451 • 19~q O. 21.;'1, '6t. 6 10. 2122. 28.7 3t08. 2ez. 1 73i1. 19C10 O. 215'1. ,95. b 511 • 2190. 2Q.8 3761. 280. 201tl. I CI CI 1 O. 269. 432. 7 0 1. 22bO. 31.0 4t1b2. 278. 22C12. 1'1'12 O. 260. l) 7:5. 752. 2B2. 32.3 5215. 271. 2509. IQCl3 O. 2'1 I • "i \ 1 , pOB. 2400. 33.6 b022. 27S. 28'11J. !9QiJ C. 303. "ib5. e613. 2t183. 35.0 0890. 2il<. 3117. ''1<15 O. 31S. /. \ 0 • '1c5. 2527. 31:>.b 1815. 270. 338'7. lqQI:> I 2 • 327. ,.5 A • qQ7. 2573. 38.8 8812. 270. 3b51. 1:)'11 12. 3UO. 11 I). 11\03. 2b1Cl. I.jO.6 '1875. 266, H23. 19'18 12. 3'5!J. 707. 1133. 26b9. U2.5 11001'1. 2b3. (j\B'5. IQ<lq 12. 308. 821. 12 0 7. 27L I.j. '1a.s \22\S. 25<1. 4/j1l/.l. 2000 12: 383. 8<13. 12 8 7. 27bl.j. 41:1 •• 13502. 256. u700. 20111 12. 3'18. ..3. IJ 7 3. 2813. 1.j8.8 14875. 253. tl9'53. 2002 12. 1.1 1 ij • 103'1. I/Jb,. 28bll. S 1.2 ,oHI. 250. 5202. 2003 12. 431. 1,22. IS6u. 2'1\6. 53.6 1790'5. 2t17. SUUq. 20Cu 12: IIU8. I ;:ll n. 16 70. 2<108. 50.3 1<1575. 2U4. 5693. 200'5 12. IJ61:). l~n6. 17 8 3. ~ 021 • 5'1.0 21358. 2 0 1, SCi.3o. 200b 12. UB!.!. llJo<l. 1q06. 3076. 62.0 2321:>/J. 23<1. 6172. 20117 12. SOti. 1'i21. 21l37. 3132. 65.0 25301. 2.30. 01.1013. 200/\ 12. 524. 1 /, £l \ • 2\17. 3188. 08.3 271.178. 23U. 6btl2. 21)0<1 12. StiS. 17 71. 2328. 324b. 71 .7 2~806. 2.31. to'l7!. 2 ~ I 0 12. Sb7. 1 Q II • 2LlC/0. 3301.j. 7S./j 32295, 22<1. 710.3 • 2011 12. 5a<l. 21lb2. 2b 0 4. 3361.j. '7C1.2 3 4 '15'1. 227. 732<1. 2,' 12 12: 6 t 3-2;:0;>5. 2p50. 3 U2tl. 83.2 3 7 809. 225. 7S5a, 2013 12. 637. 2LlOI. 30'51. 3U86. 87.5 £108bO. 223. 7777. ?014 12. 663-2,,<11. 32 b 6. 354C1. '12.0 ,"0121:>. 221. 79QA. 2015 12. 61\9. 27<1b. 3tlQ'7. 3012. C/6.6 47623. 219. 8217. 2016 27: 717. :3 niB. 3762. 3078. 102.3 51385. 218. 8435. 2(')17 27: 7 1J 6. 3,</</. 3</7\. 3678. 108.0 55351,. 213. 86a8. 20\8 27. 77&. 3~ql. U1C/3. 3678. 11 4 .0 S'1Su9. 208. 8851. 201<1 21. 807. .3'l<lu. 'lilCS. 3678. 120.(1 bH71. 204. '1061. 2020 27. 8H. .3 A I O. "6 7 5. 3678. 127,1 0 8 1:>52. lC1q. '1200 • ~f'rl 2021 27: 872. 41\38. 0938. 3678. 1 H.2 73590. 1<15. Q455. 20n 27. <107. 4;1110. 52 15. 3678. 1 4 1.8 788011. I'll • <l6 U5. ~~ 2023 27. qU4. UC;37. 50;08. 3678. 14Q.8 8 4 312. 18b. '1632. 2!1?11 27. 981. IIAOQ. 5R18. 3678. 158.2 ClODO. 182. 1001a. 't--tb 2);>5 27~ 1021. SnQ8. bl 4 b. 3b78. 167.1 1<6276 • 176. 10192. 2!"6 27. 1061. 5uOU. 6/J"'2. 3678. 170.5 102708. 17u. 10367. ...... ........ 2·127 27. 11 04 • 572B. 6A5Q, 3678, 18b.5 10<1627. 171. 10'337. ~ ""I ?12R 21: II U ~. 6n72. '2 4 7. 3678. 197.0 11/)8711. 1&'7. 101011. ~0.?q 27. 11 q ~ • 61J3b. 76 5 7. }b78. 20'3.2 12u~31. 163. 10867. ~C) 2:. >0 21. 121.12. tlA22. B n91 • '!O78. 220.0 132022. 160. 11027. '-D~ 2031 21. 1291. 7-'32. 8'5 5 0. 3678. 232.5 lt1l!7? 156. 11183. 2·)32 27: 131<3. 7t-6b • 90lo. 3078. 2<l5.7. 150208. 153. 11330. 2033 2'7: 1397. 5,26. <lS4Q. 3&78. 2SQ.o lSQ7S7. 150. 111180. I-IARZA ENGINEERING COMPANY ~ l II. ~ i t ,\ .. , t Ii. , , I it. • j. • CA P''f:DFlAL FALLS P~QJECT I'lIfS£L At,. TE: ",.A T I vI:. erST OF ~(j"EY: .(;70 f'.;FLATlO,", RATE: .040 F lJ1: i,.. ESCALATION RATE= .020 DISCOUNT RATE· .080 l'lE"EilE"JC£ I") A TE. :: J A "I..JA i'ol V 19.;0 ALL COSTS 1"1 l 1000 FIXE(I Oi' " FL'EL ENfi<G'Y COST OF CUt-lUL4Tl\lE P;(~SENT CUMULAT!IIE VEAR COSTS COSTS rOST TOTAL GENERATED ENERGV TOTAL ",a,PH p • .,. 104 ... ", CfcNTS/t<;",H Iq~1J O. 20U. ;)31, u'5'5. 1131 S. 2'1.0 1435. 2<1&. 29b, 1~1I."I o • 21.;' ;)52, £leS. 1872. 2£1.8 /fOOt 293. 58q. lql'\+> o. Z21. ~76, u9 7. 1<132. 25.7 1 ~q7. 2<10. 879. jge'7 o. • no. 102. 532 • 1993. 2b.7 1929. 287. 11 co. I'~ A8 O. 2H. ,30, s09. 20S7. 27.7 2U98. 285. l u Sl. 19!'1q O. 209. "'li • 610. 2122. 28.7 31 08. 282. 17]1.1, jQ9() O. 2Sq. ,Q5. ,,5£1. 2190. 29.1'1 3701. zeo. 2011.1, lQql o. 2&9, 1.132, 701. 2201). 31.0 "'4e2. :78. 22<12. r9 C1 2 o. eAO. 1173. 752. 2B2. 32.! 5215. 277. 25e'1. IQ93 0: 2<11. <;17. 11°8. 2'100. ,B.e 0('122. 275. 28/111. 1<, q IJ O. JO!. "oS. I\b8. 246!. 35.0 6890. 271.1. 3117. 19<15 O. 315. I'd (I. '125. 2527, .s6.b 7615. 270 • 3387. 19qb til! !27. ~58. <:199. 2573. 38.8 881U. 270. 36"7. lQCl7 1 II. 3<.10. 710. 11)05. 2619. 40.6 987'1. 2be. :3<1211. 19qil 1 j,j • 351.1. 767. It 35. 2009. 42,S 1 ! (; 1 II • 203. U1B7. 1<;199 1 /l • 3611, P27. 12° Q. 27\4. 41.1.5 122i?1. 25<1. 1111'10. 2000 14. H3. $19'5. 1?8<1. 276 4 • /le.7 13512. 250. 11702. 2001 11.1 • 3'18. <:Ib3. 1,)75. 2813. 48.9 l<1bB7. 2'53, 11'155. 21j1l~ 1" • 111 II • I1'l39. lu67. 2801.1. S! .2 11l355. 2S'l. '5205. 2003 14. ill!. 1 i 22. tsob. 2916. 53.7 1 H21. 21.17. '51152. cQlllj tt.: 4118. 1 ~ 10, 1,,72. altoS. se.3 l tt !;9!. 2ul.I. 5&ge. 20o'S 1 II: t.:bb. l'Oe, \785. ,!'l21. 59.1 21378. 21.11. 5938. 200(' 1 /,j • /,jail. I~09. 1901\. 30 7b. 62.0 23280. 239. e 1 77. 21)07 I 1,1 • S('U. 1<;21. 2039. 3132. oS.1 25:)25. 236. bllil. 20011 1 (j • 5?~. 1/,1.11. 21 7Q. 31 ~8. oB.3 27504. 2311 • obl.l7. .?00Q 1 ;j • 51:5. 177 I. 23 3 0. 321.16. 71 .8 2<;1!lJ4. 232. cB711. 2010 I 4. 567. 1 () 1 t • 21192. 330/,j. 75.u 32325. 229. 71011. 2011 HI. seq. 2"62. ChCe. ,30IJ. 79.2 31.19<:;1. 2i!7. 7335. ('ot2 11.1 : e13. 2;125. 211.'52. 31.12/i. 83.3 378U3. 225. 7560. 20 tJ HI : o:n. 2qOl. 30S}. 3 IJ 8b. 87.e U0890. 223.' 778l. 20llJ 1 u. 6~J. 21:)91. 32 0 8. 351J9. 92.1 ..1.116ll. 221. 800u. 2(115 Il.1 • 689. 219&. 3u Q 'h 3b12. '16.9 1.170e3. 219. 8223, 1016 32. 717. 3n!8. 37°7. 3e78. 102.11 51£130. 218. 8~ U I • 201'7 32. 740. 3199. Jo7b. lb7B. 108.1 551100. 213. 8055. 2018 12. 77b. 3,91. 1.11 9 8. 3&78. I 11.1 • 1 S<lbO/j. 209. 8803, ~ 2019 32. llO7. 3<;94. I.IIJ3J. 3678. 120.S 64037. 201.1. 90b7. "l) 2020 32. 839. 3AtO. 1.16 8 0. 3078. 127.3 b8717. 199. 92b 7. x: 20(>1 32. S '12. i.I~3A. 4Q1.I3. 3678. 13u.u 73l:>bO. 195, 9llo2. fb zon 32. 907. 4?80. 5;>20. 3618. 1(11.9 7f}679. 191. '16':)3. (b ~ 2023 32. QIJ Ij. II':;!]. 5<;13. )b78. 1119.Q 811392. 187. 9839. "f... 202IJ 32: 981. /.IRO<l. S~2!. 3678. 158.3 90215. 182. 10022. ~ 2()2S 32. 1021 • 5~q8. /) 1 5 1. 3&78. Ib7.2 9036&. 17B. 10200. (b ,"i 202b 32. 1061. SaOll. &ll'H. 3678. 17e.7 1021:163. 175. 10375. 21)27 32. I Ill!.!. 572 8 • e!'\6/.1. 3678. ISb.b 109727. 171 • 105~5, ~ () 2028 32~ 1 1 48. 6i17 2. 72 5 2. 3078, lQ7.2 110979. 11:17. 10712. ~ ~Oi?q 32: 11<11,1. 01.131.1. 7b o 2. 3e78. 208.3 121.1e1.l1. lb3. 1087b • I 2:)30 32. 1?1I2. bIl22. 80 9 6. 3678. 220,1 132737 • toO. 11030;. '-0 0\ 20'1 32. 1291. 7?32. 80;'S5. 3e78. 232.b l'H2Q2. 1St.. 11192. <?C32 32 : 13/.13. 7"eb. 9(\<11. 3076. 21l5.S I:'03lJ. 153. l!3l.1S. 2')33 32. 1197. 8i2b. Q0;51.1. lb78. 259.8 ISQb87. 150. 111.1Q5. I-tARZA ENGINHRING COM?ANY ~"~--"-'-' -~-------- .. II. t .. " 1. " & .. • i & .. , .. Ie C.ul-<FDRAL FALL5 P~OJECT "IESEL AlTEk'~ATIH COST OF ~O'JEY= :0<:;0 !NFLAT!O'J RATE: .040 FUEL ESCAlATION RATE: .020 DISCOuNT RATE: .OllO REF"ERENCE O~TE : JH,UARy 19/10 AlL COSTS IN s 1000 FIxED O+M fUEL ENERGY COST OF CUMUlATIvE PREstNT CUMULATIVE YEAR COSTS COSTS rOST T(1TAL GEkERATEO ENERGY TOTAL IOiORTH p.w. ~>lH CE.NTS/KI'fH 19Su O. 204. ~31. 1l35. 1815. 2'1.0 '135. 2(Hl. 29b. 19~5 O. 213. '52. /lbS. 1872. 2'1.8 qOO. 293. 5e9. 1Qllb O. 221. ~7b • iJ97. 1932. 25.7 1397. 290. ~79. 1'11\7 O. 2V'l. ~02. ,,32. 1993. 20.7 1929. 287. Ilbb. I Q IlI-i O. 2H. 'no. C;b9. 2057. 27.7 2498. 285. lU~I. ICJ>lQ O. 2'19. '61. ~,1 O. 2122. 28.7 3108. 21\2. 173'1. 19C;0 O. 259. ,'l5. b 5lJ • 211i0. 2'1.8 3761. 2AO. 201U. 1991 O. 2b9. iJ32. 7 0 1 • 2260. 31 ,0 U"b2. 276. 2292. 1992 o • 280. 073. 7'S2. 2332. 32.3 5215. 277. 2Sb9. 1993 o. 2C) 1. 1:;17. 1\08. 2UCb. 33,0 b022. 275. 28uu. IQ9 .. O. Jr.3. C;hS. 1\61'. 2 0 E3. 35,0 0890. 27'1. 3111. lQ Q5 O. 315. ~IO. Q25. ?'527. 3b .b 7815. 270. 3387. l'1 9 b 1 b. 3il7. ,.,58. 1(101. 2573. 38.'1 8816. 271. H58. 1997 1 b. 300. 710. 10b7. 2619. '10.7 91;83. 2b7. 3925. !Q'18 10. 354. 767. 1 t 37. 2009. 42.6 11020. 203. 11188. I'19Q 10. 3bil. 1\27. I? 11 • 2714. OU.6 12231. 2bO. U448. 2000 16~ 31',.3 • 1193. 12 9 1. 27btJ. 46.7 13';,22. 257. a705. 20('\1 16. 3'1>\. (lo3. 1377. 2813. Uq.o 1469'1. 253. U958. 2002 16. 410. 11'13 9 • lLJo9. Z8bU. 51.3 1636'1. 250. 52011. 2003 16. U 31 • 1'22. lc:;68. 2916. 53.8 17937. 2'17. 545b. 2004 16. U41i. 1'10. 16 70 • 2 9 68. 56.U 19611. 244. 5700. 201'15 16. 466. I~Oo. 17 8 7. '021. 59.2 21398. 242. 5942. 20(\6 1 " • OAI.I. 1 /J o'l. 1 'l I 0 • 3076. 62.1 23308. 239. 6 181. 2:)(17 lb. 500. lC:;21. 2r,41. 3132. b5.2 2';,31.19. 237. 6U17. 2008 16 ! S2U. II, /J I • 2 t 8 I • 3188. 06.4 27530. 234. 6651. 200Q 10. 5lJ5. 1771 • 2332. '3246. 71.8 29862. 232. &883. 2010 16. 5117. 1 Q 11 • 2a 9 u. 3304. 75.S 32355. 229. 7113 • 2011 lb. 56Q. 2(162. 26 6 e. 336U. 79.3 35023. 227. 7340. 2012 lb. 613. 2,,,5. 211'54, 3 4 2a. 83.4 37877. 225. 7565. 201 '3 16. 637. 21101. 3(,)55. 3<':00. 87.6 '10932. 223. 7788. 2010 16. 603. 2<;91. 32 7 0. 35/J9. 92.1 44202. 221. 8009. 201'; lb. 689. 2796. 3<;01. 3612. 96.9 U7703. 219, 6229. 2016 35. 717. 3';18. 37 7 0. 3678. 102.5 514 n. 219. 84U7. 2017 3S~ 7!J6. 3199. 3q7'1. 3678. IC8.2 55U52. 214. 81,,61. 20PI 35. 776. 3HI. U 20 I. 367A. 11 0 • 2 59653. 209. 1;870. 2019 35. B07. 3594. 4!. 3 6 • 3678. 120.6 01.1089. 20U. 9074. 2020 35. 83Q. 31\10. 4683. 3678. 127.3 68772. 200, 9273 • 20?1 35: 872. ut'\38. Uq 0 6. 3678. 13u.S 73718. 195. 9ab9. lntt, 2022 35. '107. 4280. 52 2 3. 3678. l U2.0 789 4 0. 1 q 1 • 9659. ~~ 20:>3 35.1. QOIl. LJc:; 37. 50;11". 3678. 150.0 8(1(156. 187. Q8Ub. 2024 35. Q~ 1. /Jlln9. 5'12(;. 3678. 158.0 90282. lIn. 10029. 2020; 35. 1021. 5n98. 6t 5 1.1. 3678. lb7.3 'l6U36. 179, 10207. ~ni 2020 35. 1061 • SLJOLI. 6<;00. 3678. 17&.7 102936. 175. 10382. 2021 35. 11 OU. 572 8 • 6'167. 3678. 18b.7 109803. 171. 10S';2. , 2028 35~ 11 L18. 6n 72. 7255. ]078. 1 9 7.3 117058. 167. 10719. \O"'t 2029 35. 11 qa. 6036. 766'5. 3678. 208.4 124723. 163. 10883. ~f) 2030 35. 12'12. 6A22. 80 9 '1. 3678. 220.2 132822. 1 b 0 • 11043. 2031 35. 1291. 7232. 8558. 367a • 232.7 141380. 151". 111 99. \j)~ 2032 35. 13(13. 7~66. 9(')44. 3678. 245.9 :50"24. 153. 11352. 2"33 35. 1397. 8;26. 9557, 3078. 259.8 lS 99 81. 150. 11502. l-tARZA ENC;NEE~ING COMPANY ! .. L ~ U U I I Year Ite.m ((uarf~r Preconsfrucfion Activifies OrgDnijation) Land Selecfion dha Alf~rni1five 5fucly Declaration of Infenflon (If' Re~.) F~a5ipility stll"Y Prov/~/on~1 Fln.1 Environmenfal F£R.C Lic.I1Ss Aff'lica fion Preparation Review Ofher Permits F/nfincin9 Oe5'9n)Confr~cf Oocllmsnf.s (Award Con5frucfion Mobil(Jaflon Quarry a"d Sfripl'l"g Oiv.r~ion Tunl1t!1 [).m P~n'stocl<. PoW.rhou4. Turh/l1tIs .nd t:; en~raft:)r .. Tran.$mission T.~tin~ ana Commis~ionin, I--IAR.ZA ENGINEERING COMPANY· AUGUST 1979 1979 /~80 .3 4 I Z :3 4 - -.. 1981 1982 I 2 3 4 I 2 3 4 • • • - I -----= -- EXI-/IBIT c-7 1983 2 3 4- • - • • - .A.LA.~I<.A Pf:)WEI( AUTHORITY CATH~D~AL FALLS PRo,",eCT IMPLEMENTATION SCHEDULE Appendix C-A GEOLOGY Regional Geology General Formations of Southeast Alaska vary from Lower Ordovician volcanics (in some places deposited in marine environments) and cherts to poorly consolidated recent glacial (fluvio- glacial and glacio-marine) clastics. The older (Tertiary and older) beds are often intricately folded and faulted. Folding and faulting apparently occurred in several different episodes in the past, and, judging from current seismic activity and apparent differential uplift of opposite sides of the Chatham Strait, continue in the present. Stratigraphy In general, the older (pre-Tertiary) sedimentary rocks are marine as evidenced by black shales, cherts and limestone, or their metamorphic equivalents, e.g. slates and marbles. Volcanism, which is still present, has occurred inter- mittently since the early Paleozoic. This is evidenced by basalt or andesite volcanic flow rocks, or welded tuffs in unmetamorphosed areas and by greenstones in metamorphic sequences. Plutonic activity has occurred during at least four geo- periods -the Silurian, Jurassic, Lower Cretaceous and Lower Tertiary. Plutonic rocks vary from granites to gabbros. In places, rock sequences have been subjected to low grade regional metamorphism which has produced schists, green- stones, slates and marbles. Bedding is often difficult to differentiate from foliation in many of these sequences. In addition to the regional metamorphism, aureoles, or zones of contact metamorphic rocks, surround many of the plutonic rocks. Structure Southeast Alaska is a part of the Coast Range of the west coast that extends from California northward to the Alaskan Peninsula. As such, it is a broad belt of interconnected ranges that has been subjected to several episodes of folding and faulting and plutonic intrusions. C-A-I ... ... ... • to .. ,"" .. ... The several episodes of folding, and faulting, and plutonic intrusions have resulted in extremely complex geology. This geology is additionally complicated by a system of strike-slip faults where horizontal movement has been large enough to bring different facies of contemporanous strata into juxtaposition. These faults generally trend northwestward in conformity with the structural grain of the area and often have large vertical movements. Some are apparently active. Seismicity Orogenic Earthquakes. The seismic history of Southeast Alaska, while short, shows a high level of activity. A large amount of this appears to be related to the seismic activity of the circum-Pacific orogenic belt (or "ring of fire"). This belt is characterized by a deep oceanic trench (the Aleutian Trench) a principal tectonic lin~ with epicenters of shallow earthquakes and active or recently extinct volcanos (the Aleutian Islands) with epicenters of earthquakes originating at depths near 100 km. This Pacific orogenic belt is the classi- cal concept of thrust faulting extending to substantial depths. Earthquakes foci increase in depth as distance from the oceanic trench increase • Master faults, primarily strike-slip in character, account for much of the seismic activity of Southeast Alaska. These faults, shown on Exhibit C-A-l, occupying and bounding the Coast Range orogenic belt, can in places be identified to pass through the area. Major seismic activity attributed to these faults is described below. The map of epicenters, generally shows a correlation between faulting and seismic activity. (a) The Fairweather-St. Elias-Chugach Fault is the largest and most active in coastal Alaska. Activity associated with this fault resulted in the Lituya Bay earthquake of July la, 1959. This movement was at least 70 feet lateral and 21.5 feet vertical. Other large earthquakes, including the Prince William Sound, Alaska, earthquake of 1964, and the Yakutat Bay earthquake of September 10, 1899, may also have originated on this faul t. (b) A second major fault, the Denali-Chatham Strait Fault passes through the Alexander Archipelago along Chatham Strait, joining the Fairweather Fault west of Prince of Wales Island. The northern end of this fault is considered to be active and this activity is believed to have formed scarps along the Alaska Range. There is no reported evidence of movement of the fault; however, the Denali-Chatham Strait Fault is long and C-A-2 it should not be assumed that it is inactive. Some severe earthquakes appear to have originated on the northern part of the fault. Many other faults appear to be related to the Chatham Strait -Fairweather Fault system. Within the area of Southeast Alaska, these faults, in general, are considered to be inactive or dead faults, in that they have not moved during the Holocene. Earthquakes in the area often cannot be related to known surface faults and may be presumed to be indigenous to the area. Design for such earthquakes should be on a zonal basis. It should be noted that seismic activity is largely concentrated between the Chatham Strait and Fairweather Faults and along and to the west of the Fairweather Fault. Sites significantly east of the Chatham Fault should be expected to experience a lower level of activity. Volcanic Earthquakes. Several large earthquakes have been attributed to volcanic eruptions on the Aleutian Islands. These have resulted in tsunamis. Tsunamis or Tidal Waves. One of the effects of earth- quakes can be the formation of seismic sea waves or tsunamis. Generally these are generated by submarine earthquakes; however, earthquakes with epicenters on land can also cause tsunamis. Within the area of Southeast Alaska, tsunamis can generally be expected to be generated in the Aleutian Trench, along the Fairweather Fault, or in the Japan Trench. Several have been reported that can be attributed to movement along the Fair- weather Fault. Potential tsunami generation could also occur in Southeast Alaska by earthquakes on the Chatham Strait Fault; and one reported in 1899 in Lynn Canal may have originated on this fault. Powerplant sites on or very near the coast could be damaged by tsunamis. Physiography The overriding factor in the formation of the present terrain of Southeast Alaska has been Wisconsinian glaciation. Glaciers apparently originated from ice caps on the larger islands, and then spread into the lower areas as valley and tidewater glaciers. In some areas, local mountain glaciers resulted in the formation of cirques and hanging valleys. Retreat of glaciers occurred approximately 10,000 years ago, a short period of time from a geological standpoint. C-A-3 Removal of glacial ice loads resulted in substantial rebound of land masses at some places (approximately 700 ft. for Douglas Island as reckoned from present sea level). Because of the short period of time since glaciation, drainage systems are often poorly integrated. Streams are immature, flowing through valleys with oversteepened sides and with steep gradients in places, and through shallow isolated lakes and muskegs in other places. The rebound phenomena apparently are not present in all islands. Furthermore, the phenomena have been complicated by rising sea levels following melting of glacial ice and possibly differential movement along major faults, such as the Chatham Strait Fault. The results of these factors with reference to project area are that: (1) The upper parts of Cathedral Falls Creek and Gunnuk Creek drainages are poorly integrated, apparently in part formed by ablation moraines and in part rock drumlins; (2) Some uplift resulting from rebound has resulted in both; and creeks forming sharply incised valleys near their mouths. (3) Courses of both creeks are, in places, controlled by linements in bed- rock. Debris Avalanches and Landslides A major consideration of some sites and reservoirs in valleys with oversteepened sides could be debris avalanches of soils and of weathered and broken and glacier deposits which could fill the reservoir and damage project facilities. The literature of the area reports instances of destructive debris avalanches and other mass wasteage phenomena. Many scars are found on aerial photographs, observed from planes, or found on the ground attesting to commonness of these phenomena. Bent tree trunks on some slopes indicate creep movement and potential instability. In general, debris avalanches occur on overly steep slopes, i.e. slopes exceeding 36°. This is slightly steeper than the commonly accepted 33° angle of repose for talus deposits. Commonly the debris avalanche involves relatively thin cohesionless soils and thin surficial layers of broken and weathered rock. In some cases the layering of broken and weathered rock results from stress relief joints which are generally parallel to the surface and which appear to have been formed as a result of relief of stress following melting of glaciers. C-A-4 '" ... ... .W ,41 .. ... " .. Triggering mechanisms can be a large increase of soil moisture due to rain or disruption of drainage due to construc- tion activites, logging, or other activities that remove vegetation. Earthquakes also can trigger debris avalanches. Rock falls from cliffs are one of the mass wasteage phenomena. Good engineering practice will eliminate hazards to projects from this source. Other types of landslides of either rock or soil probably occur in Southeast Alaska. These do not appear to be factors in the area of these projects. Cathedral Falls Geology Physiography The elongated hills, marshes, and shallow lakes in the vicinity of Cathedral Falls are considered to be topographic forms developed by glaciation, possibly an extensive tidewater glacier. Cathedral Falls Creek near its outfall is a meander- ing, subsequent stream which apparently is joint or fault con- trolled. The falls is apparently due to headward deepening of the stream following the rebound of the area after melting of the glacier ice cap. Slopes of valley sides below the falls are steep and tree covered. At places, deposits of talus have formed. These slopes may be unstable in places. Potentially unstable material, however, generally is only the shallow cover of soil and broken rock. Slides or debris avalanches should not present an operational problem. The stream valley above the falls has gentle slopes. These slopes are heavily forested although some areas above the Project have been logged. Formations at the site are limestone, which is a relatively soluble rock. There is some minor evidence of solution of the limestone such as widening of joints at the falls and pitting of the cliff at the falls. However, no evidence of widespread or deep solution of the limestone was seen. Design stage exploration should be made adequate to positively define the extent of solution. The geologic history of the area, which is of rebound following glaciation, suggests that solution, if a factor, would be shallow and localized. It is not anticipated that solution would have a significant impact on the Project. C-A-5 .". ... Seismicity Cathedral Falls is located east of the Chatham Strait Fault in an area that is relatively inactive seismically. No active faults have been recognized in the area. However, as all of Southeast Alaska has been demonstrated to be seismically active, provisions for strong shaking should be incorporated into designs. While the powerplant for Cathedral Falls would be located near tidewater, the site is considered to be safe from tsunamis. This consideration is based upon the protection afforded by Baranof and Kuiu Islands from tsunamis originating on the Fairweather Fault and by Kuiu Island from tsunamis that could originate on the Chatham Strait Fault. Investiga tions Geological mapping of the project area by the USGS is reported in USGS Bulletin 1241-C, Stratigraphy of the Keku Islets and Neighboring Parts of Kuiu and Kupreanof Islands Southeastern Alaska, by L.J.P. Muffler (1967). The stratigra- phic nomenclature established by this report is used in this present report. General interpretations of geologic structure were also reported. These interpretations were confirmed and augmented by Harza personnel. Harza personnel visited the site in June 1979. The results of this visit are presented in this report. Site Geology Stratigraphy. Two geologic formations form the bedrock in the vicinity of the Project. These formations as described from the oldest to the youngest are: Permian-Pybus Formation: This formation consists of a series of thick beds of light grey to tan siliceous, finely to medium crystalline, hard limestone. Irregular nodules of limey chert or cherty limestone occur in these beds. Triassic-Hamilton Island Limestone: This formation outcrops at the head of the falls and upstream where it is in fault contact with the Pybus Formation. In the project area rocks of this formation consist of thinly bedded (1/4" to 2"), laminated, dark grey to black, hard argillaceous limestone; interbedded with dark grey to black, thinly bedded chert and argillite. The results of petrographic analysis of rock samples taken from the site is given in Exhibit C-A-2. C-A-6 Structure. In addition to the fault boundary between the Hamilton Island and Pybus Formations at the head of the falls, a relatively large fault believed to trend about N 10° W passes to the west of the site and separates both formations from the older Permian Cannery Formation. This fault, which is generally concealed by forest cover, passes approximately 300 feet to the west of the falls. Upstream of the falls, the Hamilton Island Limestone is folded into a sharp southwesterly trending syncline. In addition to bedding plane partings, the Hamilton Island Limestone is intersected by a series of sheared joints trending N-S to N 35° E and dipping vertically or 80° W. Below the falls the Pybus Formation dips moderately to the south. In this area, the formation is intersected by a series of strong joints or small faults striking N 70° E and dipping vertically. Zones of breccia paralleling these small faults are found in this area. Rock of the formation at the falls is also intersected by a strong joint or sheared joint subparallel to bedding. This joint is considered to be a stress relief joint formed as a result of removal of the load of glacial ice from the area. Engineering Geology Dam, Spillway, and Penstock Intake. Stripping for the dam should remove organic matter, soil and loose rock to permit examination of the bedrock surface. Stripping is estimated to be about 2 feet in the channel and 5 feet on the abutments. A key way, grout trench about 2 feet deep and 4 feet wide should also be excavated. Zones of weak rock should be excavated and cleaned by jet and backfilled with concrete. Open joints should also be jetted clean and slush grouted. It is estimated that grout holes for the proposed grout curtain should be drilled about 10 feet deep. This curtain, which should be an exploratory type, should have holes angled at 45° to provide a greater incidence of interception of steeply dipping joints. Penstock. Penstock supports and bend anchors should be founded on bedrock but should not require any special provisions for anchoring. Penstock Tunnel. The small tunnel envisioned for the penstock should generally require only nominal support. This would consist of rock bolts with wire mesh in the crown. C-A-7 .. .. .. . ., ... Provisions, however, should be made for greater support in the event fault zones are encountered. Powerplant. The powerplant, which would be located near the cliff bordering the upstream or northeast side of the pool formed by the falls should be founded on bedrock. This is assumed to be at a shallow depth below the pool's surface. Slopes behind the powerplant should be scaled of loose rock and then stabilized with rock bolts and wire mesh. Large trees that could be blown down causing damage to the powerhouse should be cut. Proposed Design Exploration Dam, Spillway, Penstock, and Intake. Exploratory drill holes proposed for the exploration of these features is esti- mated to total 450 feet. These should be to: 1. Define stripping depths 2 • Determine structural conditions of bedrock 3. Determine if solution of bedrock has occurred. Penstock Tunnel. Two holes totaling 150 feet are needed for the tunnel. One should be drilled near the tunnel portal. A second should be drilled near the cliff to determine if open joints are present near the cliff face. Powerplant. One drill hole should be drilled at the pQl.V'er- plant site to determine depth to bedrock and condition of bed- rock. The hole would be about 30 feet deep • C-A-8 \. EXHllJlT C-A --I l' \ o 811e/c 8ttlr LI/(' ® GlII1l1ul( Cr'~ k ' . .... ., •••••• , I .. ,... I .... I ". . ,. .. .. ' .. ... 1 '. . ' . .... -(~ _........... -, ~ .... ~""'I"-W .,z.. .......... • . .. ..... ...,........ . -.. -:!, '. ' . ........ , J ...... I ' .. . " '. '-Eq~N/): ./ ~pic.~"f.' tlf tJI'f"9IM~1 "limN' of I~!rh -----Fllult~ doff~tI wh.,~ CDnC ... tllIr ,",.".d. NOTE,: 0"" 6flrth9v.~ of ;J.O + m~"itud. or N .,. ,itf."$ify .rl $hown. '. ® ("fll,tlr41 rtills Cr,,1c ~ G.rllilt1 CrIll< @ Thly#r Crt,/r @ Ji/llJ C rtlle ALASKA "OW~1f A.UTHO"'TY LOCATIONS OF FAULTS AAlO EARTHQUAKE EPICENTERS .... ,,.. Exhibit C-A-2 PETROGRAPHIC INVESTIGATION OF SAMPLES FROM THE ALEXANDER ARCHIPELAGO, S.E. ALASKA. A.F.Koster van Groos ... Cathedral Falls'l:reek, 200 feet upstream of falls M~croscopic: dense black fine-grained rock, fine layering. sedimentary origin. Microscopic: fine layered very fine-grained d 9 rk brown material with large number of small globules of chert-like material, 0.1-0.3 mm in size Conclusion: Thin-bedded argillite with microscopic chert globules. The dark material is too fine to identify. Probably Hamilton Island formation USGS l24l-C Cathedra'l FaIls Creek, downst ream from falls Macroscopic: white chert with numerous small fossils, light grey-brown, fine grained dolomite present Microscopic: Chert, richly fossiliferous. Dolomite in rhombs, 0.5-1 nun in size Conclusion: Chert and dolomite from the Pybus formation USGS l24l-C Conclusions: All the samples from the Alexander Archipelago seem to be rather normal. The only exception is the sample from Thayer CreeK, at the lower downstream site. The degree of weathering of all samples is slight. Most fractures are healed with either chert-like deposits, quartz, or calcite. The degree of alteration is often substancial, e~pecially when the original rock is of volcanic origin .. - - ,,,.. ' .... .. ' .... Appendix C-B HYDROLOGY Clima te The climate of the project area is largely maritime with occasional incursions of continental air masses. Therefore, the climate is mild and humid with much precipitation. The primary factor influencing the climate is the Aleutian low pressure area, which is semi-permanent in the fall and winter but tends to migrate in the spring and summer. Tempera tures The maritime influences cause temperatures to be mild and uniform. The occasional incursions of continental air cause considerably colder temperatures for short periods. Exhibit C-B-l shows average and extreme temperature for a climatological station in the project area. Precipitation The normal cyclonic wind pattern of the low pressure area, aided by high mainland mountains to the northeast, results in a high percentage of the winds being from the southeast quadrant. In addition, these southeasterly winds bring rain a far greater percentage of the time than do winds from other quadrants. Therefore, southeastern exposure is an important factor in the precipitation pattern, and hence runoff, of the project area. In latitudes south of the project area, the cyclonic circulation results in the prevailing winds being from the southwest. Therefore, moisture from warmer seas is carried in a generally northward direction, passing over cooler water thereby lowering the air temperature. This, along with cyclonic convergence and local orographic effects, produces copious rainfall but with large variations over short distances. Precipitation, however, varies less from year to year, and from season to season, than in most places. The moderate temporal variation in rainfall is highly favorable to hydroelectric power but the geographical variations make the computation of power potential from ungaged basins somewhat uncertain. This problem is discussed later under "streamflow" . C-B-l .. - -... OIl - Storms tend to be general and for extended periods. In- tense precipitation of the thunderstorm type is very rare, and is never as intense as in warmer climates. This leads to very much smaller flood peaks in these small basins than are found in warmer humid areas. Flood volumes, however, can be large. Precipitation data are shown for a climatological station in the project area in Exhibit C-B-l . Streamflow Streamflow data are far more extensive in the project area than are precipitation data. Streamflow data integrates the conditions for the entire drainage basin about the gage. There- fore, streamflow records generally are far more valuable than precipitation records in estimating the water supply at the various sites. Elevation, orientation, and location affect both the amount and distribution of runoff. These three factors are discussed below: Effect of Elevation Studies were made by the Alaska Power Administration and its predecessor, the U.S. Bureau of Reclamation, of the effect of elevation on runoff in the Alaskan panhandle. (Takatz Creek Project, Alaska-Juneau, September 1967). The curves of Drawing 1113-906-21 of that report, shown here as Exhibit C-B-2, indicate that the average increase in unit runoff for the areas studied is about 0.0045 cfs per square mile for each additional foot of average basin elevation. The project areas covered herein generally have much lower precipitation and runoff per unit of drainage area than the areas studied in the above report. The project drainage basins in general also have higher elevations than the basins above the stream-gaging stations. Therefore, it is considered prudent to use an elevation adjustment two thirds as large as indicated above. Therefore, an increase in unit runoff of 0.003 cfs per square mile for each foot of additional average basin elevation is adopted. An independent check of this elevation adjustment factor was made by comparing the one year of simultaneous record at the upper and lower gages on Mahoney Creek near Ketchikan. The records of these stations confirmed the value of 0.003 cfs per square mile for each foot of elevation. The confirmation is only partial, however, because of the poor quality and short records of the Mahoney gages. Where the basin is small and where most of it is within the spillover area at the upwind basin divide, the average elevation of the upwind divide is substituted for the average basin eleva- tion and a partially subjective factor is applied to adjust for C-B-2 the effectiveness of the spillover. Mr. Robert Cross, Admini- strator of the Alaska Power Administration, who is highly experienced in Alaskan hydrology, pointed out instances where there is a noticeable dropoff in precipitation within two miles of the upwind divide. This phenomenon is considered in estima- ting the adjustment factor. Elevation not only affects the mean annual runoff but also the seasonal distribution of the runoff. Drawing 1113-906-20 of the Takatz report shows the seasonal effect for the Baranof Island area. This same effect was used in the project area. The drawing is shown on Exhibit C-B-2. Effect of Orientation Examination of precipitation and runoff records, discussions with meteorologists and hydrologists, and published reports all indicate that exposure to the southeast has a significant effect on precipitation and runoff. The "Climatic Atlas of the Outer Continental Shelf Water and Coastal Regions of Alaska -Volume I, Gulf of Alaska" by the Bureau of Land Management, 1977 indicates that the predomi- nant winds in the project area are from the southeast and that such winds are accompanied by significant rainfall a much greater percentage of the time than are other winds. Therefore, presence or lack of exposure to the southeast was given careful consideration in transposing runoff from gaging stations to project basins. Effect of Location The effect of location was taken into account by selecting as index stations gaging stations in the general vicinity of the project. Streamflow Records Since these are reconnaissance level studies, published data of the U.S. Geological Survey, along with computer analyses by the USGS, are used to define the streamflow at the gaging stations. Some of the streamflow records are very short. Annual variations in runoff, however, are very moderate in the project area. Therefore, average runoff records of five years or longer are used without adjustment. Records were available only for 1977 for several stations. Comparing the 1977 runoff with long term runoff for stations having long records indicates that 1977 was fairly representative of the long term average with C-B-3 some stations having somewhat greater than average runoff in 1977 and others somewhat less. Therefore, records for the single year 1977 are used without adjustment but with caution. All comparisons of runoff are made on the basis of cfs per square mile to eliminate the variable of basin size. Runoff based on these comparisons is subject to inaccuracies in the published data and to uncertainty in accounting for elevation, explosure, and location, ~s discussed earlier. Runoff Computation The runoff is estimated on the basis of drainage area, basin elevation, and exposure comparisons with gaged basins. Basin elevations also are computed for gaged basins used in the comparisons. Drainage areas are determined by planimetering 1:63,360 scale or 1:250,000 scale topographic maps. Basin elevations are determined by laying out grids over the basins and averaging the elevations of each grid over the basins and averaging the elevations at each grid intersection. Grid scales are selected for each basin such that they averaged about 40 grid intersections. There is a gaging station on Hamilton Creek, about 2 miles to the south of the Cathedral Falls, having fairly comparable runoff. The station has two years of record (1977 and 1978) and is rated "poor" to "fair". This station has an average adjusted runoff of 3.52 cfs per square mile. Using the grid system on a 1:250,000 scale map gives an average basin elevation of about 500 for Hamilton Creek. The Cathedral Falls Creek basin averages about 590 in elevation. Using 0.003 cfs/sq. mi. increase in runoff per foot of elevation gives 0.003 (590-500) or 0.27 cfs per square mile increase for the basin or a total of about 3.8 cfs per sq. mi For the drainage area of 27.2 sq. mi. the average flow is 103 cfs and the mean annual flow volume is 1236 cfs months. The average annual flow is then distributed over the year in accordance with the seasonal relationships shown on Exhibit C-B-2 to arrive at average monthly flows. Average monthly flows are shown on Table C-B-l. Flow-Duration Computations Computer printouts of daily flow were obtained from the U.S. Geological Survey for Big Creek near Point Baker on Prince C-B-4 .. ... - - ... .... ."" Table C-B-l AVERAGE MONTHLY INFLOW AT CATHEDRAL FALLS Month InfJ.ow, cfs January February March April May June July August September October November December Annual Average 79 116 92 123 99 56 38 59 113 180 160 120 103 of Wales Island. Big Creek has a drainage area of 11.2 sq. mi., an average basin elevation of 500 ft. and a unit runoff of 7.8 cfs/sq. mi. The printout includes flows for the station exceeded 95, 90, 75, 70, 50, 25 and 10 percent of the total days in the record, irrespective of season of occurrence of such flows. The flow duration values for this index station then are multiplied by the ratio of average flow at the project site to the average flow for the index station. The resultant flow duration curve for Cathedral Falls is shawn on Exhibit C-5 of the main report •• Probable Maximum Flood The probable maximum precipitation (PMP) falling in 24 hours on an area up to 10 square miles is derived from a provi- sional isohyetal map included with a report on probable maximum precipitation being prepared for later publication by the National Weather Service. Correction factors are given in a provisional curve prepared for that report. From these two curves, PMP quantities are derived for durations divisible by 6 hours from 6 hours to 72 hours. By substracting the PMP for consecutive durations, incre- mental precipitation is derived for each 6 hours for the 3-day storm period. These values are maximized sequentially (placing the 12 6-hour values in the most critical sequence). The high- C-B-5 - est increment is placed in the 7th period, the second highest in the 6th period, the third highest in the 8th period, the fourth highest in the 5th period, etc. Basin retention is taken as 0.05 inches per hour. No initial retention is used for the basin because the PMP probably will come in a very rainy season. unit hydrographs are estimated by the Snyder method. Six hour unit hydrographs are used to simplify manual computations. Flood peaks, flood volumes and Creager's "C" values for the peaks are given in Table C-B-2 and the PMP hydrograph is shown on Exhibit C-B-3. Table C-B-2 PROBABLE MAXIMUM FLOOD SUMMARY Drainage Area, sq. mi. Flood Peak, cfs Flood Volume, cfs Creager's "C" Other Hydrologic Factors 1.86 12,300 31,100 22 Other hydrologic factors that are briefly noted but not studied in detail were evaporation and sediment. Evaporation Evaporation losses are small and alreany reflected in the streamflow records of streams having natural storage. In the case of new storage, evaporation will be partially or wholly compensated because presently vegetated land areas will be flooded. Sediment Sediment observations in the panhandle area of Alaska indicate that suspended sediment will not be a significant problem in basins not containing active glaciers. It is probable that bed load will be more nearly normal than will suspended load. Projects having only small pondage may experience a gradual diminution of the pondage. For projects having active storage it is unlikely that sediment will be a problem. Downstream channel degradation should be allowed for in alluvial channels, but is unlikely to be a serious problem. C-B-6 JAN FEB MAR APR MAY JUN AVERAGE TEMPERATURE 31. 2 32.1 35.0 40.8 46.0 52.1 HIGHEST TEMPERATURE 51 52 55 70 74 88 LO\'[£ST TE~fP ERA TURE 1 3 5 22 28 36 AVERAGE PRECIPITATION 5.30 5.43 3.10 3.92 2.98 1. 99 AVERAGE SNOWFALL 13.2 12.1 5.7 1.6 0 0 Harza Engineering Co., August 1979 KAKE JUL AUG SEP OCT 54.5 55.9 50.1 43.6 76 75 73 65 39 41 31 16 2.55 4.15 4.97 7.51 0 0 0 1.2 NOV DEC ANNUAL 38.7 32.6 42.7 60 56 88 13 -4 -4 7.40 5.21 54.51 3.7 10.5 48.0 Alaska Power Authority Cathedral Fall s Hyd ro 1 og i c Do. ta () ! Exhibif C-B-2 ~ ________________ -____________ -______ -_________________________ 1 >~ llJ -.J ltJ llJ l,) -:x: t') ~ lJl c: u... TAKATZ CREEK PROJECT RUNOFF - and PRECIPITATIOiV DISTRIBUTIOiV I, To!Cotz L. Outlet CIl 2 Tol(o",-,t..::.z...;:C:.:...r'~--o---<o-____________________ --!J > w ..J ltJ 2 3. Borono' R. <t UJ Ct: <t UJ ~ ~ ~ 1< ~ ~ :c: <! 4. Deer_ -,L.,--_ .. ~ _______ -u_-o llJ '-.r -r..! a lI.J ..... -0: ~ -l.IJ :;; I<X'O- May B June \ \-Novomb.,a April P.,lod JulyS October V Period ,..~._8-"!.~~!i~r.E~iy~ ____ ----D------------o--__ , ~.~i!~"_C!~e.;ip~ __ _ o 110 2,'0 3 '0 4'0 5 10 6 '0 7 10 8'0 RUNOFF or PRECIPITf.TlON as P;:':RCENT of ANNUAL NOTE: 1-5 On east~id~ ~ 6-9 on \.,~sts;de of Island. o November-April o May-June C1 J u ly-Oc tob~r L APA DrvJo ~o • . ) 1113-905-20 ---~~ ., ... ,,. ,,. ," ,,.. Appendix C-<: ENVIRONMENT (Gunnuk Creek and Cathedral Falls Projects) Introduction and Summary The Cathedral Falls Project is the project selected in the main report. The selection of the Cathedral Falls Project over the Gunnuk Creek Project is based on several considerations, among which were the results of the environmental reconnaissance. Therefore, both projects are presented in about equal level of detail in this appendix. The potential environmental effects of the Cathedral Falls Project are identified and mitigating actions are recommended. Permit requirements are analyzed and requirements presented for additional data needs. The principal environmental review agencies for the Project would be the U.S. Forest Service Land Management Planning office and/or the Alaska Department of Fish and Game Habitat Protection Service. Based on the information presently available, these agencies do not perceive any critical environmental issues which would preclude project development. However, the potential for significant project impacts appears to be greater for the Gunnuk Creek development than for the Cathedral Falls site. Gunnuk Creek development would affect the quality of Kake's water supply and would probably have greater impact on downstream salmonid habitat. For these reasons, development of the Cathedral Falls site appears to be preferable from an environmental viewpoint at this level of study. Additional environmental data will be required, of course, and the projects would be subject to the federal, state, and local environmental review and-regulatory process. There are existing barriers to fish passage downstream of both sites, so that fish passage facilities would not be required at either site. Magnitude of Potential Impacts -Cathedral Falls Potential impacts on migratory salmonid populations due to slight changes in streamflow, temperature, and other parameters can probably be minimized by proper project design and operation. Dewatering of the falls would reportedly not be opposed by local residents. Loss of wildlife habitat and effects on C-C-I .. . ~. ... .,f visual esthetics due to access road and transmission line construction would be minimal • Blasting operations during construction would probably have to be scheduled to avoid the salmon spawning season because of the extreme sensitivity of eggs in the early stages of devel- opment. Hourly variations in stream discharges for power pro- duction would have to be studied and controlled so as not to interfere with spawning. Recommendations The U.S. Forest Service and Alaska Department of Fish and Game should be asked to assist in assembling the ecological data required to determine potenti~l project effects in greater detail. These agencies should also be kept advised of refine- ments in project concepts and desi9n so that their input can be included as planning proceeds. Other agencies with major review and/or regulatory responsibilities should also be contacted. These agencies are listed in the body of this appen~x. General Site Locations and Land Ownership Project works on Gunnuk Creek would include a power darn located in Section 26, T56S R 72E, Copper River Meridian, Alaska, and a relatively large upstream storage reservoir in Sections 16, 17, 18, 19, 20 and 21, T56S R 73E, formed by a darn across each of two branches of the stream. The power damsite is on land selected by the Kake Tribal Corporation and the storage reservoir and darns would be located on Sealaska Corporation overselection land (USFS no date). Sealaska may choose not to exercise its option to acqrfre this tract and it may revert to U.S. Forest Service (USFS)-management. The Cathedral Falls Creek project would be run-of-the- river and provide minimal forebay storage at a darn located in Section 26, T 57S R 74E, Copper River Meridian, Alaska. The site is located on USFS land in the Tongass National Forest, in Value Comparison Unit (VCU) 425 of Management Area Sll (USFS 1979). VCU 425 has been assigned a Land Use Designation (LUD) of IV in the Tongass Land Management Plan (USFS 1979). Water and power developments, utility corridors, and permanent roads are permitted on LUD IV lands in the Tongass (USFS 1975, 1979). l/ Acronyms are listed on Exhibit C-C-l. ~ C-C-2 "" .. ... ' .... ' .. .. Project Areas and Natural Resources Lakes and Streams. There are several small lakes in the Gunnuk Creek watershed, but muskeg areas are infrequent. Stream water quality is excellent and the creek is Kake's potable water source. The town maintains a Z}mber buttress diversion dam, impassable to anadromous fish,-just downstream of the proposed power damsite. The stream has an extensive intertidal area at its mouth (ADFG-DCF no date). Cathedral Falls Creek drains extensive muskeq areas and has a characteristic transparent brown color. The creek flows into Hamilton Bay through an extensive intertidal area. Tidal influ- ence extends nearly to the foot of Cathedral Falls, which is immediately downstream of the proposed damsite. The falls are impassable to anadromous fish . Vegetation. The vegeta~}on in the Gunnuk Creek watershed is typical of hemlock-spruce-coastal forest. The forest w~st and south of the proposed project storage resevoir was loggeo between 1973 and 1975 and pioneer vegetation in these areas is now well established. There are plans to log on other tracts west and northwest of the storage reservoir site in the next few years. The storage reservoir area itself has not been logged and there are no present plans to harvest timber there (USPS no date). The vegetation in the Cathedral Falls Creek watershed is typical of hemlock-spruce coastal forest, with considerable areas of muskeg. Much of the lower watershed has been logged, but only above probable reservoir level. Wildlife Resources. Wildlife in both project areas includes black bear, Sitka black-tailed deer, timber wolf, moose (occas- ional), and other smaller mammals (Kadake 1979). Birds are abundant in both areas. Bald eagles are very common along the shoreline near the tidal flats off Gunnuk Creek near Kake. They also frequent Cathedral Falls Creek downstream of the falls during the salmon spauning season (Kadake 1979). Fisheries Resources. Gunnuk Creek is catalogued as an anadromous fish stream (No. 109-42-004) (ADFG 1975) and is known to support spawning runs of pink and chum salmon (ADFG-DCF no date). Steelhead trout and coho salmon are also reported but the principal species are pink and summer chum ~/ Anadromous fish are those that spend some part of their life in salt water and return to fresh water to spawn. 11 Scientific names of flora and fauna mentioned in the text are listed on Exhibit C-C-2. C-C-3 • salmon, with pinks in greatest abunda~7e (ADFG-DCF no date, Kadake 1979). Coho salmon escapement-is small, and fall chum are not reported (Kadake 1979). The fish spawn from the exten- sive intertidal zone upstream to the foot of the Kake water div- ersion dam (ADFG-DCF no date, Kadake 1979). Alaska Department of Fish and Game (ADFG) escapement data show a peak escapement during the last 20 years of 10,000 pink salmon in 1968 (ADFG-DCF no date). Escapement apparently declined in subsequent years (ADFG-DCF no date) but has improved recently, with the 1978 escapement reported as "very good" (Kadake 1979). Kadake (1979) reports that the spawning run (pinks and summer chum) usually peaks during the first two weeks of August and terminates by early September, and that the small steelhead run begins early in April. Kadake (1979) reports that students in the Kake Public Schools have operated a small pink salmon hatchery facility at the foot of the municipal dam for several years, and raise 200,000-300,000 pink salmon fry annually for release into Gunnuk Creek. The town and Kake Tribal Corporation will begin construction in 1980 of a larger hatchery facility near the mouth of the creek. This hatchery will be operated by pro- fessionally trained local personhel and will produce one million juvenile salmon annually, including king salmon. No information was obtained on resident fish in Gunnuk Creek above the water diversion dam. Cathedral Falls Creek is catalogued as an anadromous fish stream (No. 109-42-009) (ADFG 1975) and is reported by Kadake (1979) to support spawning runs of chum, pink, and coho salmon below the falls. Summer chum is the principal species using the stream, with the peak of the run occurring in August. Some coho use the stream, with the spawning run taking place mainly in September. Kadake (1979) reports resident trout in Goose Lake upstream of the Cathedral Falls site, but no other information on resident fish was available. Endangered and Threatened Species. The only fish or wildlife species listed by the U.S. Fish and Wildlife Service as endangered or threatened in Alaska are four migratory bird species: the Eskimo curlew, the American and Arctic peregrine falcons, and the Aleutian Canada goose (USFWS 1979). These birds would be expected to pass through the general project area only infrequently and the project should have no effect on them. il Number of adults returning to spawn. C-C-4 Potential Project Impacts and Mitigation Measures Access Roads and Transmission Lines. There are numerous logging roads in t~Gunnuk Creek project area with excellent access to the proposed storage reservoir site. The road leading to the Kake water diversion dam would have to be extended approximately one-half mile to provide access to the proposed power damsite and could be used for the transmission line route. Extension of the road could cause some erosion and runoff of sediment to the stream. Downstream deposition of sediment could be harmful to fish eggs and juveniles. Proper construction procedures would minimize erosion problems. A small amount of wildlife habitat would be eliminated by extending the road. The Cathedral Falls damsite also has excellent access by logging roads which pass within 1/4 mile of the site. Poten- tial impacts and mitigation measures for road extension are the same as those mentioned for the Gunnuk Creek site. Construction of Dams and Generating Facilities. Anadromous fish do not pass the municipal water diversion dam on Gunnuk Creek downstream of the project area. There are no known plans for constructing fish passage facilities at the existing dam, presumably because introduction of salmon runs to the upper watershed could cause deterioration in the quality of the Rake municipal water supply, since salmon die after spawning. Any project dams located above the existing municipal dam therefore would not require fish passage facilities. Construction activities in the stream could disturb substrate material and cause resuspension and downstream redeposition of fines, which could adversely affect fish eggs and young in the downstream spawning areas. Bank erosion could also occur during construction with the same result. Proper construction procedures and scheduling could reduce these impacts. Blasting and other noise may cause wildlife to temporarily abandon the construction area, but the animals should return to most parts of the area once construction is completed. Provisions would have to be made during dam construction to pass adequate stream flow so that downstream aquatic habitat is maintained, especially during the anadromous fish spawning and rearing season. Kake would also have to be assured an uninterrupted water supply. Clearing of approximately 600 acres of vegetation would probably be required in the storage reservoir area. Clearing C-C-5 and inundation would eliminate wildlife habitat at the storage reservoir site. Some clearing may also be required at the power damsite downstream. Cathedral Falls is a natural barrier to anadromous fish, so that a hydropower installation upstream of the falls would not require fish passage facilities. Potential impacts of instream construction activities and bank erosion would be the same as for Gunnuk Creek. Blasting operations at the Cathedral Falls site would probably have to be scheduled to avoid the salmon spawning season because of the proximity of the site to spawning areas. Eggs in the early stage of development are easily killed by even minor shocks (Logan 1979). Provisions for passage of adequate flow during construction would be necessary, especially during the salmon spawning and rearing seasons. Some clearing of vegetation at Cathedral Falls would probably be required but would not be extensive. Operation. Water quality in the proposed Gunnuk Creek storage reservoir might deteriorate over the long term, since water temperatures would be higher in the impoundment than they presently are in the free-flowing stream and since the reservoir would act as a nutrient trap. Such deterioration might event- ually affect the Kake municipal water supply, anadromous fish spawning habitat downstream, and the water supply for the new salmon hatchery. Assessment of the magnitude of such impacts would require data on stream water quality and watershed characteristics such as nutrient runoff rates. The Gunnuk Creek project, with the power outfall structure located just upstream of the existing municipal dam, would not dewater any part of the stream. A previous design concept would have placed the power outlet at tidewater and would have reduced or eliminated streamflow in the reach of the stream which supports salmon spawning activity. The principal potential concerns, if the Gunnuk Creek project were developed, would be the long-term effects on Kake's water supply and on downstream salmonid populations. These populations could be adversely affected by changes in discharge regime, water temperature, dissolved oxygen and other water quality parameters, and suspended sediment and bed load downstream of the project. The most critical of these parameters are discharge and water temperature, since even small variations from natural conditions can have significant adverse effects on anadromous fish eggs, juveniles, and adults. Adult salmon returning to fresh water to spawn will not or cannot enter a stream if water temperature is too high or discharge too low. After the eggs are deposited in the gravel, adequate discharge is required to aerate the eggs and carry away waste materials. C-C-6 Dissolved oxygen concentrations must also be high. These conditions must also be maintained after the eggs hatch and before the young fish (alevins) emerge from the gravel to become free-swimming fry. Deposition of fines over spawning bed gravels can cause suffocation of eggs and alevins by preventing percolation of water through the gravel. Excessive bed load movement can cover too deeply, crush, or expose eggs and alevins, resulting in high mortality. Juvenile fish in the free- swimming fry stage are also highly susceptible to changes in stream habi ta t. Water temperature, in addition to affecting the timing of stream entrance and spawning by adult fish, also determines the rate of development from egg through alevin to free- swimming fry. The rate of development is critical to the survival of juvenile fish. In particular, pink and chum salmon juveniles do not remain for long in the streams, but swim or are carried downstream to brackish or salt water upon reaching the free-swimming f~y stage after emergence from streambed gravels. If warmer than normal water temperatures have accelerated the intragravel stages of development, this downstream movement may occur before sufficient numbers of food organisms are available in the coastal feeding areas, and the young fish may suffer high mortality from starvation. Differences from natural stream temperatures of as little as 2 or 3°F during the egg-alevin development period can result in significant losses (Meehan 1974). Water temperatures which are too cold can retard deve- lopment, with similar consequences. If water quality problems develop in the proposed Gunnuk Creek storage reservoir, downstream dissolved oxygen concen- trations could be reduced and carbon dioxide concentrations might be increased, with detrimental effects on anadromous fish populations, especially with a low level discharge structure. The storage reservoir could also cause increased downstream water temperatures. The magnitude of possible changes would depend on reservoir thermal characteristics and the level of the reservoir from which water is withdrawn. The project would modify the natural stream discharge regime and could affect downstream fish habitat, migration, and development of egqs and juveniles. Further data on natural flow regimes will be required before more detailed assessment can be made of any project related flow changes. Project operation may have to be adjusted to provide adequate downstream flows during the salmon spawning and rearing seasons. The Cathedral Falls reservoir would have minimal storage so that effects on general water quality downstream would be ex- pected to be minor. Downstream water temperatures and dissolved oxygen concentrations might be slightly changed, depending on C-C-7 • the level of the reservoir from which water is discharged down- stream and on water retention time in the impoundment. Tempera- ture changes could be reduced or prevented by installation of a multi-level intake or perhaps by a properly placed conventional intake. The natural stream discharge regime would probably be only slightly modified, but project operation might have to be adjusted at times to provide adequate downstream flows for salmon. The falls would be dewatered part of the time, but this would not affect fish populations. According to Kadake (1979), local residents would not object to the esthetic impact of dewatering the falls .in connection with development of a more economical supply of electricity. Site Development Preference The potential for significant project impacts appears to be greater for the Gunnuk Creek development than for the Cathedral Falls site. Gunnuk Creek development might affect the quality of Kake's water supply, whereas no such constraint exists for Cathedral Falls Creek. In addition, long-term impacts on downstream salmonid habitat would probably be greater for Gunnuk Creek than for Cathedral Falls. For these reasons, development of the Cathedral Falls site appears to be preferable from an environmental viewpoint at this level of study. Regulatory Requirements and Reviews Federal. If the project is located even in part on Tongass National Forest lands, a USFS Special Use Permit must be obtained, which in turn might require a USFS Environmental Impact Statement. USFS would prefer to have hydroelectric developments located entirely on private or tribal corporation lands to avoid the necessity of processing a Special Use Permit application, and an exchange of National Forest and tribal land for such purposes would be looked upon favorably (Brannon 1979). The Kake Tribal Corporation has expressed some interest in acquiring land for a hydro site (Kadake 1979). The project would have to be licensed by the Federal Energy Regulatory Commission (FERC) if federal lands are in- volved. If the project is located entirely on tribal land, the FERC may not have jurisdiction. Such a determination would be made by the FERC itself, and may depend on additional factors, such as whether the affected stream is navigable or is deemed to affect interstate commerce. The FERC has authority to declare a stream to be navigable or that it affects the interests of interstate commerce (Gotschall 1977). The FERC would make its jurisdictional decision after receiving a "Declaration of Inten- tion" which fully describes the project, land ownership and the stream. C-C-8 .... ,.;t If the FERC determines that a license is required, the project would be in the minor project category (less than 1.5 MW installed capacity), and the application for license would have to include the following (FERC 1978): Exhibit K. Definition of project lands and boundaries. Exhibit L. Description of project structures and equipment. Copies of necessary federal, State of Alaska, and local permits, approvals, and certifications. Applicant's Environmental Report, including: 1 • Description of project and mode of operation, 2. Description of the environmental setting, 3 • 4. 5. Description of expected environmental impacts, and enhancement and mitigation measures, Description of project alternatives, including alternative sites and sources of energy, and Description of consultations with federal, State, and local agencies during preparation of the environmental report. The information required for this report should be commensurate with a preliminary environmental assessment to determine the need for an Environmental Impact Statement. Whether or not a USFS Special Use Permit and an FERC license are required, the following federal permits must be obtained: U.S. Army Corps of Engineers (USACE) -Section 404 Federal Water Pollution Control Act (FWPCA) permit for discharge of dredge and fill material into U.S. waters; Section 10 Rivers and Harbors Act permit if the stream is determined to be navigable. U.S. Environmental Protection Agency (USEPA) -Section 402 F~vPCA Na tional PoIlu tant Discharge El imi nation System (NPDES) permits for point source discharges. Construction phase and powerhouse sump pump discharge NPDES permits will be necessary, and depending on the outcome of a current suit to classify hydroelectric facilities as point source discharges, an NPDES permit for project operation could also be required. C-C-9 ... - Other federal agencies which would probably review an FERC license application and the applications for other federal permits include U.S. Fish and Wildlife Service, National Marine Fisheries Service, the Heritage Conservation and Recreation Service, the Alaska Power Administration, and the Bureau of Indian Affairs. The REA would also review the FERC license application if REA funding is to be used for the project. During the review of the FERC license application and the applications for permits from USFS, USACE, and USEPA, any of these federal agencies may determine that preparation of an Environmental Impact Statement is required. REA would also be empowered to make such a determination. State of Alaska. Permits and review concerning environ- mental aspects of the project which would be required from State agencies include (ADCED & ADEC 1978): 1. 2 • 3 • 4 • Department of Environmental Conservation -Certificate of Reasonable Assurance for Discharge into Navigable Waters (in compliance with Section 401 of the FWPCA)i Waste Water Disposal Permit (the Department may adopt the NPDES permit issued by USEPA as the required State permit) . Department of Fish and Game, Habitat Protection Service -Anadromous Fish Protection Permit -required of any hydraulic project located on a catalogued anadromous fish stream. This permit may impose stipulations on construction timing, project design and operation requirements, and other mitigation measures. Department of Natural Resources (ADNR), Division of Land and Water Management -Water Use Permit (authorizes darn construction and appropriation of water). Office of the Governor, Division of Policy Development and Planning, Office of Coastal Management -review of development projects in Alaska's coastal zone to insure compliance with coastal management guidelines and standards (AOCM & USOCZM 1979). Coordination. To assist those who must obtain permits from one or more federal, State of Alaska, or local agencies, the applicant may submit a single master application to the Alaska Department of Environmental Conservation (ADEC), who will then circulate the application to the other appropriate State agencies for comment and review (AOCM & USOCZM 1979). C-C-IO ... The State permits and review listed above are all included in this procedure which is not mandatory but rather intended to aid the appl icant. In addition, the Division of Policy Development and Planning (DPDP) of the Office of the Governor, through the A-95 Clearinghouse System, acts as lead agency in the coordination of the review of environmental reports, Environmental Impact Statements, federal assistance programs, and development projects (AOCM & USOCZM 1979). Although no explicit or procedural criteria are applied to these reviews, Alaska does employ A-95 as a major vehicle for solicitation and coordination of agency responses to proposed energy development activities. Satisfaction of FERC and Other Agency Requirements Consultation and cooperation with federal and State natural resources agencies during project planning is required by the FERC and is also necessary during the process of application for permits from these agencies. If project planning proceeds, the principal environmental review agencies would be the USFS Land Management Planning Office and/or the ADFG Habitat Protection Service (Brannon 1979, Reed 1979). Based on the information presently available, these agencies do not perceive any critical environmental issues which would preclude development of the project (Brannon 1979, Reed 1979). Additional environmental data will be required, of course, and the project will be subject to the federal, State, and local environmental review and regulatory process outlined previously. In the course of future project planning and development it ~ is recommended: 1. 2. That USFS and ADFG be asked to assist in assembling the ecological data required to determine in greater detail the magnitude of potential project effects on anadromous fish runs. The other poten- tial impacts outlined previously should also be discussed with these agencies. That USFS and ADFG be kept advised of refinements in project concepts and design and that their input be solicited and included as planning proceeds. C-C-ll 'CdIf ... ,;tI ... ,,.. 3. That other agencies with major review and or regula- tory responsibilities be contacted, including USACE, USEPA, ADNR, ADEC, and DPDP. ADEC and DPDP will be able to render assistance in the review and permitting process through their master permit application and Clearinghouse programs, respectively • C-C-12 References Alaska Dept. of Commerce and Economic Development and Alaska Dept. of Environmental Conservation (ADCED & ADEC) 1978. Directory of Permits, State of Alaska, March 1978. Juneau. Alaska Dept. of Fish and Game (ADFG), 1975. Catalog of Waters Important for Spawning and Migration of Anadromous Fishes, Region 1. Juneau, 97 p. Alaska Dept. of Fish and Game, Division of Commercial Fisheries (ADFG-DCF). No date. Stream Survey Report -Gunnuk Creek - 109-42-004. Juneau. Alaska Office of Coastal Management and U.S. Dept. of Commerce Office of Coastal Zone Management (AOCM & USOCZM), 1979. State of Alaska Coastal Management Program and Final Environmental Impact Statement. Juneau, Alaska, and Washington, D.C. May 3 0, 1 9 7 9 • 5 7 8 p. + rna p s • Brannon, Ed. 1979. Group Leader for Land Management Planning and Regional Environmental Coordinator, U.S. Forest Service, Juneau, Alaska. Personal communication. Federal Energy Regulatory Commission (FERC), 1978. Short Form Hydroelectric License. Federal Register, Vol. 43, No. 176 - Monday, September 11, 1978, pp. 40215-40219. Gotschall, Don, 1977. Memorandum: Phone conversation with Federal Power Commission on licensing procedures. U.S. Dept. of Energy, Alaska Power Administration, Juneau. Kadake, Marvin, 1979. Supervisor, Tlingit-Haida Regional Electrical Authority, and commercial fisherman, Kake, Alaska. Personal communication. Logan, Richard, 1979. Alaska Dept. of Fish and Game, Office of the Commissioner, Habitat Protection Service, Juneau. Personal communication. Meehan, W.R., 1974. The Forest Ecosystem of Southeast Alaska: 3. Fish Habitats. USDA Forest Service Gen. Tech. Report PNW-15. Pacific Northwest Forest and Range Experiment Station, Portland, Oregon, 41p. Reed, Richard, 1979. Alaska Dept. of Fish and Game, Habitat Protection Service, Regional Supervisor, Juneau. Personal commu nica t ion. C-C-13 ... '. ... • u.s. Fish and Wildlife Service (USFWS), 1979. Fish and Wildlife Service List of Endangered and Threatened Wildlife. 50 CFR 17.11; 43 FR 58031, Dec. 11, 1978; amended by 44 FR 29478 f May 21, 1979 • u.S. Forest Service (USFS), 1979. Tongass Land Management Plan Final Environmental Impact Statement (Two Parts). Alaska Region, Forest Service, u.S. Dept. of Agriculture, Juneau, Alaska, March 1979. u.S. Forest Service (USFS), 1975. Tongass National Forest Guide (1975 Draft). Alaska Region, Forest Service, u.S. Dept. of Agriculture, Juneau, Alaska, 253 p. + app. u.s. Forest Service (USFS), No date. Logging map, Kake-Portage off ice • C-C-14 .... ," .. .. .... ,,.. ADEC ADFG ADNR DPDP FERC FWPCA LUD NPDES REA USACE USEPA USFS USFWS VCU ACRONYMS Alaska Dept. of Environmental Conservation Alaska Dept. of Fish and Game Alaska Dept. of Natural Resources Exhibit C-C-l Division of Policy Development and Planning Federal Energy Regulatory Commission Federal Water Pollution Control Act Land Use Designation National Pollutant Discharge Elimination System Rural Electrification Administration U.S. Army Corps of Engineers U.S. Environmental Protection Agency U.S. Forest Service U.S. Fish and Wildlife Service Value Comparison Unit '''' ... SCIENTIFIC NAMES Common Name hemlock, mountain hemlock, western spruce, Sitka bear, black deer, Sitka black-tailed moose wolf eagle, bald curlew, Eskimo falcon, American peregrine falcon, Arctic peregine goose, Aleutian Canada salmon, chinook (king) salmon, churn (dog) salmon, coho (silver) salmon, pink (humpback) steelhead Trees Mammals Birds Fish Exhibit C-C-2 Scientific Name Tsuga mertensiana Tsuga heterophylla Picea sitchensis Ursus americanus Odocoileus hemionus sit- kensis Alces alces Canis lupus Haliaeetus leucocephalus Numenius borealis Falco peregrinus anatum Falco peregrinus tundrius Branta canadensis leuco- pareia Oncorhynchus tshawytscha Oncorhynchus keta Oncorhynchus kisutch Oncorhynchus gorbuscha Salmo gairdneri ... , .. ... 1 . 2. .. 3 • • - ",01 "., Appendix C-D REFERENCES Federal Power Commission and the Forest Service -U.S.D.A. "Water Power Southeast Alaska," Washington and Juneau, 1947. Robert W. Retherford Associates, Preliminary Appraisal Report, Hydroelectric Potential for Angoon, Craig, Hoonah, Hydaburg, Kake, Kasaan, Klawock, Klukwan, Pelican, Yakutat, Anchorage, 1977. u.S. Department of Agriculture, Rural Electrification Administration, "Alaska 28 THREA ~ Power Requiremments Study", May 1979 draft.