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Gartina Creek Project A Reconnaissance Report 1979
4, October 1979 G J AS i a | a id OS PROJECT A Recomnaissance Report Prepared for the SIATE OF ALASKA ALASKA POWER AUTHORITY Anchorage, Alaska By HARZA Engineering Company Chicago, Illinois GARTINA CREEK PROJECT A Reconnaissance Report Prepared for the State of Alaska Alaska Power Authority Anchorage, Alaska by Harza Engineering Company Chicago, Illinois October, 1979 LIAR ZA ENGINEERING COMPANY CONSULTING ENGINEERS October 15, 1979 Alaska Power Authority Suite 31 333 West 4th Avenue, Anchorage, Alaska 99501 Attention: Mr. Eric P. Yould Executive Director Subject: Gartina Creek Project Summary Letter Gentlemen: We present the results of our reconnaissance study of the Gar- tina Creek Project. The study includes technical, economic and environmental evaluation 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 Gartina Creek Project. The following paragraphs briefly describe the Project and the studies which were made. The Gartina Creek Project The Gartina Creek Project is located at a falls on the creek of the same name, about 3 miles southeast of the town of Hoonah on Chichagof Island in Southeast Alaska. The Project would have an installed capacity of 450 kW and at full production level would produce about 2,170 MWh in an average year. The Table of Significant Data at the end of this letter con- tains pertinant data on the Project. A plan and sections of 150 SOUTH WACKER DRIVE CHICAGO, ILLINOIS GO606 TEL. (312) 855-7000 CABLE: HARZENG CHICAGO TELEX 25-3540 Alaska Power Authority October 15, 1979 Page Two the Project are shown on Exhibit G-2 of the report. The Project will consist of a dam, spillway, intake, penstock, powerstation and transmission line. The dam will be a low concrete gravity structure containing an uncontrolled spillway. Maximum dam height will be about 27 feet. Water will pass through a 4.75 foot diameter steel penstock 190 feet long. A powerstation will be constructed near the base on the falls. The powerhouse will be a prefabricated metal building con- taining two vertical shaft fixed blade propeller turbines. Each turbine will be directly coupled to a generator rated at 225 kW. Power from the Project will be transmitted to Hoonah over a 4-mile long, 12.5-kV transmission line. A preliminary identification of the potential environmental impact of the Project shows that there do not appear to be any adverse environmental impacts of sufficient magnitude to pre- clude project development. Anadromous fish spawn below the falls, but construction and operating procedures can be adopted that will reduce the impact of the project. 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 $4.9 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 show that the Project has a benefit-cost ratio of about one at an interest rate of 5 percent assuming differential fuel cost escalation of 2 percent. Alaska Power Authority October 15, 1979 Page Three The average cost of energy over the 50-year life of the Pro- ject, at September, 1979, price level, would be 23.7 cents/kWh. This compares with 23.0 cents/kWh for the diesel alternative. However, if inflation is considered the cost of energy from the Project would be less than that from the diesel alternative after 1995,as shown on Exhibit G-5 of the report. 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 Gartina Creek Project to be attractive if financing 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 Hoonah. The study should include an evaluation of both direct combustion and biomass conversion. A decision can then be made whether to implement the Gartina Creek Project, based on the availability of suitable financing and viable alternative projects. We would be pleased to provide you any assistance you may re- quire in these matters. Very truly yours, LES LLL Arthur E. Allen Project Director TABLE OF SIGNIFICANT DATA Gartina Creek RESERVOIR Water Surface Elevation, ft msl Normal Maximum Minimun Tailwater Elevation, ft msl Surface Area at Normal Max. El.,ac Estimated Useable Storage, ac-ft Type of Regulation HYDROLOGY Drainage Area, sq mi Avg. Annual Runoff, cfs/mi2 Streamflow, cfs Maximum Monthly Average Annual Minimum Monthly DAM Type Height, ft Top Elevation, ft msl Dam Volume, cy SPILLWAY Type Crest Elevation, ft msl Width, ft Design Discharge, cfs PENSTOCK Diameter, ft Length, ft Type Shell Thickness, in 217 212 15 36 None Li5)9) Wil, 29 Conc. Gravity 27), 225 1585 Conc Ogee 217 55 6200 475 210 Steel 0525 TABLE OF SIGNIFICANT DATA (Cont'd) Gartina Creek POWERSTATION Number of Units (Initial) 2 Turbine Type Propeller Rated Net Head, ft 65 Generator Unit Rating, kW 225 POWER AND ENERGY Installed Capacity, kW 450 Firm Capacity, kW 47 Avg. Annual Energy Generation, MWh 2170 Avg. Plant Factor, % 58 COSTS AND ECONOMICS Construction Cost, $x106 4.9 Unit Cost, $/kW inst 10,890 B/C Ratio @5% with 2% fuel escalation 0.94 Average Cost of Energy, cents/kWh 2S, GARTINA CREEK DETAILED TABLE OF CONTENTS - G Chapter Summary Letter Table of Significant Data Table of Contents Foreword Purpose and Scope of Report Background and Previous Studies Authorization Acknowledgements I. Project Setting Location and Access Population and Economy Electric Power System Utilities Existing Facilities Power Market Forecast Topography Geology Hydrology Ecology II. The Gartina Creek Project General Description Introduction Project Arrangement Project Functional Design Hydroelectric Power Production Geology, Foundations and Construction Materials General Dam, Spillway and Penstock Intake Description of Project Facilities Dam and Spillway Power Intake Penstock 1 myn ty my 1 NN HE 1 I H ' e 1 HHH ' Pree aaa GGG) Qa AAAA 1 HHH 1 NRE CG GG HHHH 1 Www Ww Q | H H | Be Iil. IV. DETAILED TABLE OF CONTENTS (Cont'd) Powerstation Switchyard and Transmission Access Roads Reservoir Spoil Disposal Environmental Aspects Project Constuction First Year Second Year Project Costs Construction Cost Operation and Maintenance Cost Project Selection and Operation Stream Regulation Characteristics Type, Number and Capacity of Generating Units Power and Energy Production Economic Analysis Methodology 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 Recommendations Organizational Framework and Financing Pre-Construction Activities Implementation Schedule -ii- PRG) AG) DAU PWNHE vaAWwPY EXHIBITS General Location Map General Plan and Sections Detailed Cost Estimate Project Selection Cost of Energy Implementation Schedule APPENDICES Geology Hydrology Environment References elon FOREWORD (G) Purpose and Scope of Report This report is to document the results of a reconnaissance level study of the Gartina Creek Project near Hoonah on Chichagof 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. The study also included an evaluation of energy alternatives in the Hoonah area. The scope of the study included the following work items: Gs Size installation and estimated project power and energy production in relation to system loads. 2. Prepare reconnaissance level analyses, preliminary design, geologic maps and layouts of appurtenant structures, Se Perform an environmental reconnaissance to identify the potential environmental impacts of the project. 4. Make a preliminary assessment of the safety hazard if any, caused or introduced by the project. Bre Estimate the construction, operation and main- tenance costs and service life of the project. 6. Evaluate energy alternatives and prepare an economic analysis of the project. lke Prepare a final report documenting the studies. Background and Previous Studies The town of Hoonah reportedly applied to the U.S. Forest Service for a permit in 1927 to build a hydro project ata site on Gartina (also called Gart-Hee-Ne) Creek. Construction of a timber crib dam was started but the project was never completed. Studies of hydroelectric power development in the Hoonah area have focused around the development of Gartina Creek, since studies completed by the Federal Power Commission in 1947 [1]—. An inventory study [2] prepared for the Alaska Power Authority (APA) in 1977 also selected Gartina Creek as the site for power development. The present studies are a direct result of the earlier report. 1/7 Reference listed in Appendix D. G-F-1 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 Chapter G-I PROJECT SETTING Location and Access The Gartina Creek Project is located at latitude 58° 04'N and longitude 135° 23"W, near the town of Hoonah on Chichagof Island in Southeast Alaska. See Exhibit G-l. The Project develops the head between the top and the bottom of a falls on Gartina Creek at a point about 3.5 miles upstream from Hoonah Harbor. Hoonah Harbor is on Port Frederick, a bay flowing into Ice Strait. The damsite and the powerstation site are accessible by foot or by helicopter from Hoonah. Population and Economy The Project would serve the town of Hoonah. The majority of the inhabitants of the project area are Alaskan Natives, predominantly Tlingit Indians. The population of the area is about 900, accounting for about three-quarters of the population of Chichagof Island. The major commercial activities of the project area are fishing and forestry. There is a seafood processing plant and a cold storage plant in Hoonah. Electric Power System Utilities Hoonah is served by the Tlingit and Haida Regional Elec- trical Authority (THREA), a rural electric cooperative with offices in Juneau, Alaska, which serves 5 towns in Southeast Alaska. Existing Facilities All power in the project area is generated by small diesel- electric units located in Hoonah. The power is distributed from the powerstation; there are no transmission lines interconnecting the town with other areas. Table G-I-l lists the generating units serving the area. All units are owned by THREA. G-I-1 Table G-I-1l HOONAH ELECTRIC SYSTEM EXISTING DIESEL GENERATING FACILIITES Nameplate Capacity, kW 1/ Unit No. Unit Total Firm — 1 500 2 600 3 600 1700 1100 I7 Largest unit out of service. Power Market Forecast The forecast of future electric power needs is based ona current forecast prepared for the utility (THREA), and on dis- cussions with the large private industries in the area (Hoonah Seafoods and the cold storage plant, both of which are served by THREA). A forecast of the power and energy generation require- ments in the project area is shown on Table G-I-2. Future requirements for THREA in Hoonah 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 recent rate increases have curtailed increases in per capital consump- tion. Over the ten-year forecast period the REA predicted per capita consumption to remain constant with load growth coming from new connections. The combined load served by THREA is forecast to increase at 2.9 percent per year, over the long term. Table G-I-2 POWER AND ENERGY GENERATION REQUIREMENTS (THREA IN HOONAH) Peak Energy Year Demand, kW Generation, MWh/yr 1978 (actual) 610 2400 1983 730 2880 1988 840 3330 1993 980 3850 The local industries have no plans for expansion. G-I-2 Topography Chichagof Island has rolling rugged mountainous terrain rising to 3400 feet near the Project. The unnamed falls at the project site is about 50 feet high with the base of the falls at about El. 150. Hillside slopes upstream of the falls are moderate and downstream of the falls are steep. Geology The falls was apparently developed by the headward deepen- ing of the stream after the rebound of the area following melt- ing of a glacier. Rock in the area of the project structures is part of the Devonian-Freshwater Bay Formation and consists of hard andesite. Earthquakes are common in the project area and the Project could be subject to severe shaking. More infor- mation on project geology is presented in Appendix G-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 O°F in the winter to highs close to 90°F in the summer. Pre- cipitation varies greatly with elevation and location. In coastal areas near Hoonah the mean annual precipitation is about 65 inches. Gartina Creek at the damsite has a drainage area of 10.3 square miles and an average annual inflow of 77 cfs or 7.5 cfs/mi2. December through March, July, and August are low flow months, with average flows below 60 cfs. High flow months are May, June and October, with average flows greater than 130 Gtss More detailed information on project hydrology is pre- sented in Appendix G-B. Hydrologic information relating to project operation is presented in Chapter G-III. Ecology Vegetation in the project area is typical of hemlock-spruce coastal forest with considerable muskeg areas. The area has not been logged but survey crews are now laying out logging roads. Wildlife in the project area include brown bear and deer, as well as many of the 200 bird species common to South- east Alaska. Gartina Creek is a catalogued anadromous fish G-I-3 stream and reportedly supports spawning runs of pink, chum, and coho salmon. More information on ecology is presented in Appendix G-C. Project impacts are discussed in Chapter G-II. G-I-4 Chapter G-II THE GARTINA CREEK PROJECT General Description Introduction The Gartina Creek Project will provide energy to meet part of the Hoonah system requirements and thereby replace some energy need that would have to be provided by diesel generators. The falls provides an opportunity to develop a net head of about 65 feet without the need for large structures. The site does not allow for economic development of reservoir storage. The plant can provide some depéndable capacity but will be primarily a source of energy when water is available. This chapter gives a description of the Project, the function- tional and preliminary design of the major project elements, the schedule for the construction of the project and the estimated project costs. Project Arranagement The Gartina Creek Project will consist of the following principal elements. a. A low concrete gravity dam across the river, just upstream of the existing falls, founded on sound rock with an uncontrolled spillway over the highest part of the dam in the present river channel. b. An intake and emergency closure gate for the power conduit and a temporary diversion conduit located through the dam on one side of the spillway. ce A power conduit approximatley 150 feet long from the dam to a wye branch, and two branches each 20 feet long from the wye to the powerstation. d. A powerhouse containing two turbines, generators, electrical switchgear, and an adjacent switchyard to contain the transformer and transmission pull-off structures. e. Other facilities including access road(s) and the transmission line. G=rr=i: Exhibits G-2 shows a plan of the project general arrangement and sections through the major structures, including the dam and spillway, the penstock and penstock anchors and the power- station. 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 city of Hoonah and its environs in proportion to the flow available in the river. The plant will operate essentially as a run-of- river plant. The reservoir as it is to be developed will provide only minimum pondage which can be used to regulate flows on an hourly basis provided there are no adverse effects on andromous fish. Hydroelectric Power Production The powerplant will have two generators rated at 225 kW each, powered by fixed blade propellor turbines of 316 horse- power each. At full utilization, the project will produce 2170 MWh in an average year. The gross operating head will vary from 66 feet to 61 feet using 5 feet of drawdown available for pondage when inflow is less than turbine discharge capacity. Geology, Foundation, and Construction Materials General A detailed description of the site geology is presented in Appendix G-A. During Late Pleistocene the low lying part of Chichagof Island, including the lower parts of the Gartina Creek drainage area appear to have been covered by ice fields, and tide water glaciers. Within this area drainage systems are poorly defined. Following melting of the ice field and removal of the ice field loads, the area, at least locally, tended to rebound with the result that streams commenced eroding their courses headward. Such action appears to occur on Gartina Creek. The falls is located in an area of hard, nearly vertically dropping, andesite beds or layers. G-II-2 Rock at the falls and at the damsite, which is approximately 120 feet upstream of the falls, consists of andesites and welded tuffs belonging to the Devonian-Freshwater Bay Formation. At the site in the area of the falls, the rock is a lay- ered or bedded dark grey, finely crystalline, hard andesite. Layers are generally about 1 foot to 3 feet thick. Downstream (approximately 100 feet) from the falls, dark grey welded tuffs are found. At the falls and the site, layers strike N80W to N70E and dip 70°S to 90° respectively. Downstream of the falls the dip flattens to about 45°S. Prominent joints, apparently stress relief joints related to removal of glacial loads occur near the base of the falls. These strike N70E and dip 15° to 25°S. The location of the site on Chichagof Island, which is be- tween the Chatham Strait Fault and the Fairweather Fault, indicates that the area is seismically very active. In addition to these major faults, numerous faults, gener- ally paralleling the Fairweather Fault, pass through Chichagof Island. One of these faults, the Freshwater Bay fault is considered to cross Gartina Creek approximately one mile downstream of the falls. The project elements will be designed appropriately to consider strong acceleration forces simultaneously in both the horizontal and vertical directions. Dam, Spillway and Penstock Intake Stripping for the dam should remove all soil and all weathered and loose rock. The bed of the channel is in part alluvial sands and gravels and in part rock outcrops. It is estimated that average stripping for the dam would be 3 feet in this area. A thick (approx. 10 feet) vertical ledge of andesite out- crops to a height of 20 feet on the east side of the channel. Minimal stripping (approximately 3 feet) should be sufficient for this part of the abutment. Above the area of outcrop of this ledge, it is recommended that stripping on this abutment be 5 feet. G-II-3 No outcrops were observed on the west abutment, however, it appears (from the irregularities of the abutment topography) that bedrock occurs at a shallow depth. For cost estimating it is recommended that a depth of 5 feet be assumed for stripping. Open joints and zones of severely broken and weathered rock and/or clay should be removed, the foundation cleaned, and voids backfilled with concrete. The grout curtain recommended consists of placing vertical holes to 10 feet depth extending up both abutments to the reservoir normal water level (spillway crest). Penstock supports will be founded on sound rock. Bend anchors at concave bends will be securely anchored into bedrock. It is recommended that these anchors be 25 foot post-tensioned tendon type anchors. The powerplant will be located on the edge of an old pool formed by the waterfall to one side of the waterfall. Bedrock in this area is shallow and little difficulty should be encountered in founding the plant on bedrock. Protection of the plant from raveling of steep slopes will be incorporated into project design. The protection will consist of scaling the slopes and then installing rock bolts and wire mesh. Large trees that could be blown down causing damage to the power house should be cut and removed. The total quantity of concrete aggregates for the low con- crete qravity dam, the penstock supports and the powerhouse substructure and adjacent training walls is relatively small. Total concrete is estimated to amount to 1865 cubic yards. The contractor could develop a quarry in appropriate andesite outcroppings near the dam site and convenient to the proposed forestry road system that will pass the project area. Alternatively, he could develop and work a quarry in the Hoonah environs. Such a quarry could be left open and used in the future as a source of rock for road surfacing, rip-rap for small breakwater structures, or protective works in the harbor area. The haul distance from Hoonah to the site is short and permits either option without cost penalty. A quarry opened in the forest area would have to be carefully restored to an ecologically acceptable condition upon completion of the project. The restoration would involve appropriate cost increase. G-II-4 Description of the Project Facilities Dam and Spillway The dam will be a concrete gravity dam with an uncontrolled ogee crest spillway over the river section where the dam is highest. The crest of the spillway is at elevation 217.0 and the top of the dam at elevation 225.0. 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 6200 cfs, of the peak instantaneous infow from the probable maximum flood with the reservoir surcharged to the top of the dam. This results in a spillway slightly less wide than the existing river channel and confines discharge to the existing channel. No storage effect is considered available to attenuate the peak inflow. In passing the probable maximum flood peak discharge, estimated to be 7850 cfs, the top of the dam will be surcharged by 1.5 feet of water. However, the dam will be stable under this load and the abutments are of rock strong enough to resist undersirable erosion. 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 1570 cubic yards of concrete. A timber buttress dam and spillway was considered as an alternative to the concrete dam. The timber dam and spillway was found to be more costly than the concrete structure. In the timber dam, concrete would still be required for footings and the timber would have to be imported from Seattle, Washing-— ton, the nearest location where it could be pressure treated to make it impermeable to water and prolong its life as a struc- tural material. Location and cost of the spillway on the east abutment would also be a problem. Power Intake The power intake will be located at the left side of the existing river channel, between the spillway training wall and the west river abutment. The power intake will have two bell mouthed entrances divided by a center pier. The intake will be provided with guides and seal plates on the upstream face of the dam for interchanging trashracks with bulk head gates; G-II-5 either of which can be lowered from a hoist at the top of the dam. Water passing 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 5 feet of drawdown of the reservoir elevation 217.0 (the spillway crest level) which can be used when advantageous for daily pondage. Inspection of Gartina Creek above the falls showed that during the larger yearly floods a considerable amount of pebbles and stones are transported along the bed of the stream. To protect the turbines against damage by stones, a pit should be excavated in front of the intake. The pit should be cleaned out annually. The dimensions of the pit will have to be deve- loped during detailed design. To reduce the cost of the concrete dam, the dam was kept as low as possible while still providing that the invert of the penstock be 5 feet above the foundation level of the dam. In addition, two 5 foot high rock sills, of rip-rap size rock, will be constructed across the approach channel to form catchments at intervals of 200 and 400 feet upstream of the dam. A drag line can be used to remove material from the catchment basins. Annual cleaning and inspection of the rock sills should be scheduled until it is established that less frequent maintenance is adequate. Penstock An exposed steel penstock with a total length of 190 feet will connect the intake to the powerstation. The exposed penstock above the falls will be provided with a continuous anchored concrete support sill and partial concrete encasement to proteck the penstock from erosion and floatation during large spillway flood discharges. The encasement concrete on the spillway side of the penstock will act to confine spillway discharges to the existing channel and keep them away from the powerhouse. The penstock has been sized for the installation of four units with a discharge of 4x50=200 cfs, and a total power output of 900 kW. Initial installation should be 2 units. A reinforced concrete anchor block will be provided both above and below the falls to take the thrust of forces involved in turning the flow and to support the free spanning penstock. G-II-6 The penstock with its supports and anchor blocks will be designed to resist a simultaneous vertical and horizontal acceleration force to provide adequate resistance to earth- quake damage. Between the powerstation and the anchor block at the base of the falls, a wye branch will be provided to divide the penstock from 4.75 feet diameter to two 3.00 foot diameter pipes. One of the 3.00 foot diameter pipes is blocked off, the other branches into two pipes which are connected to the units to be initially installed. The penstock manifolds will be supported on a rock back- fill between the lower anchor block and the powerstation and will be encased in concrete. The escarpment face of the falls behind the penstock and the powerhouse yard will be cleared of possible rock spalls and be stabilized with rock bolts and wire mesh. Powerstation The powerstation will have a reinforced concrete substruct-— ure with a prefabricated metal type superstructure above the generator room floor. Unit width would be approximately 12 feet. The turbines would be mounted in formed pits 8 feet square above the draft tubes. The overall dimension of the inital powerplant super- structure containing two units and an erection area will bea building 42 feet long by 15 feet wide by 24 feet high. The two turbines will be vertically set fixed blade pro- pellor type, available as standard inventory "package" models rated to produce at least 316 horsepower at a net head of 65 feet at 1200 rpm. At the rated output and head, each turbine will discharge 50 cfs. The generators and turbines will be directly connected by a vertical drive shaft. The generator will be rated at 281.25 kVA at a 60°C temperature rise, 0.8 powerfactor and 60 Hertz. Each generator will have a continuous overload rating of 15 percent. G-II-7 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 curcuit 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 generation from a remote central control room located at Hoonah. 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 1294 kVA. The transformer will be connected to the Hoonah substation by a single 12.5 kV cir- cuit about 4 miles long. The powerhouse will be provided with a light bridge crane, supported on separate column and support beams for purposes of unloading and erection of equipment during construction and maintenance. Accessory electrical equipment for the control and protect- ion of the powerplant and miscellancous mechanical equipment will be provided in the powerhouse. Access Roads An all-weather U.S. Forest Service road to be used for logging operations will pass very close to the dam site, and is scheduled to be completed by 1980. Access to the dam site can be easily obtained by extending a short surfaced road to the proposed dam site from the forest service road. Moderate gradients can be maintained. Access to the powerstation (at a lower elevation) could be developed by cutting a descending bench into the side of the G-II-8 existing canyon slope on the west side of the river down to the powerhouse site. Approximately 0.6 miles of access road will be required for the project. Reservoir The reservoir created by the uncontrolled spillway crest (elevation 217.0) will extend only a short distance laterally due to the height of the existing river banks and, essentially, will be confined to the existing river channel. The reservoir will extend about 0.5 miles upstream due to the very gradual gradient on the river upstream of the falls. Since economy dictates that this project be operated as a run-of-the-river plant, pondage is provided primarily to insure adequate submergence of the power intakes. The pondage could be used to increase on-peak generation daily at times of low streamflow. Seasonal storage would be available only at prohi- bitive cost, and, therefore, is not provided. The reservoir will be surcharged above elevation 217.0 when floods are discharging through the spillway. Reservoir clearing is required in the small areas between the stream bed and elevation 217.0 on both side of the stream. Spoil Disposal Overburden containing organic matter and decomposed rock removed from required excavations at the damsite probably will be temporarily stockpiled. Ultimately, the material will be placed into either the quarry excavation in compacted layers and finished off with stable slopes or transported the short distance to abandoned river meanders near the existing Hoonah landing strip. Where the abandoned river channels lie above normal high tide level they could be used for waste disposal providing that a proper wet lands disposal permit is obtained from the U.S. Corps of Engineers. The waste would be compacted and graded to facilitate drainage. Environmental Aspects A preliminary assessment of the impact of the Project on the environment is furnished. Details of this investigation are in Appendix G-C. The damming of Gartina Creek above the falls would not affect the passage of anadromous fish since the falls serves G=T1T-9 as a natural barrier. The construction of the Project may cause some disruption on the migratory and resident salmonid populations below the falls. At the present level of study there do not appear to be any major adverse environmental impacts of the Project which would prohibit its construction or greatly restrict its oper- ation. Project Construction The project construction should be carried out by separate supply and civil works contracts. A single general contractor specializing in civil works should be engaged to build the project. The general contractor should be required to construct access to the dam site and to the powerstation site, clear and prepare storage areas near the damsite and the powerhouse site, and provide 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, and mobilize his equipment and work force. First Year Before the contractor has completed “move in" and finish- ed assembling shops ‘and maintenance facilities, he will begin opening up the quarry for concrete aggregate, and strip- ping the foundation areas for the dam and powerhouse of brush, overburden, and weathered rock. By the time the quarry has been opened and the foundation prepared for pouring concrete, the contractor should have his crushing and batching plants erected and be ready for oper- ation. Diversion will 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 east side of the Gartina Creek channel which will extend to the falls. The metal pipe will be set ona concrete bedding on sound rock through the dam foundation area such that it could be incorporated into the dam concrete struc- ture as construction proceeds. It will be provided with a slide gate in a vertically set metal frame operated with a hand wheel. A concrete head wall 8 feet high will be provided to improve entrance conditions and provide rigidity, anchorage, and containment for the slide gate frame. When the dam is completed the slide gate will be closed in the next August, G=rr—-10 normally the lowest flow month, the pipe extension to the falls downstream of the dam will be removed and the pipe plugged with concrete through the dam. After river diversion is completed, the contractor will begin work on the dam and should also be ready to begin work on the powerhouse below the falls. The total concrete to be poured in the dam is 1585 cy. Assuming 10 foot wide monoliths and 5 foot high lifts, the lar- gest 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 charging, mixing and unloading cycle 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 platform over the diversion conduit. The temporary fill will be removed when the dam is completed. Some turbidity will be created by the filling and removal but the amounts will be small and the duration short. 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 with its supports and anchor blocks can proceed to completion 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 and February and possibly March due to snow, low temperatures and limited hours of daylight. If winter conditions are not too severe, or should the contractor need to make up lost time, it would be possible to continue on the powerhouse and the transmission line erection. Work would be expected to be less productive and should not be necessary under normal conditions. Second Year Early in the spring of the second year the contractor will complete erection of the powerhouse prefabricated metal super- G=IT-11 structure and installation of auxiliary electrical and mechan- ical equipment. He will then commence installation of the turbine, generators and power transformer. Four months are available for the installation of this equipment. Also, the transmission line pole erection will be completed and the con- ductors 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 August, as previously described. By the end of September in the second year the contractor can begin testing the units and making the necessary adjustments and corrections to bring the units on line by the end of November. Clean up and restoration of all construction areas at the dam site and around the powerhouse will go on simultaneously 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 G-6. 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 G-II-l and a detailed estimate is shown as Exhibit G-3. 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 construction. Detailed estimates of quantities are calculated from the project plans, and unit prices or lump sum costs are estimated for each item of work. The items within each project feature are estimated either as part of a general construction contract or of 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 G-II-12 Table G-II-1l CONSTRUCTION COST OF PROJECT (In Thousand Dollars at September 1979 Price Level) Item Cost Mobilization 500 Land and Land Rights 36 Reservoir Clearing 150 Diversion and Care of Water 170 Dam, Spillway and Intake 827 Waterconductor 332 Powerhouse 174 Mechanical and Electrical Equip. 402 Roads 444 Transmission 221 Subtotal Direct Cost 3256 Contingencies (25% +) 814 Total Direct Costs 4070 Engineering and Administration (20% +) 830 Total Construction Cost 4900 U.S. hourly rates adjusted to local conditions. Unit prices for the principal items of work are based on a construction plant designed to implement the Project in accordance with the schedule shown on Exhibit G-6. The direct cost estimated for the permanent equipment includes purchase, delivery and installation. The major equip- ment items include the turbines and governors, generators and exciters, 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 manufactures. To allow for unforeseen construction problems, changes in design, and errors or omissions in estimating, a contingency allowance of 25% is added to all costs. Based on data obtained from other hydroelectric projects an allowance 20% for engineering and owner's overhead expenses G=It-13 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 construc- tion. Operation and Maintenance Cost The Project would be equipped for remote control operation from Hoonah., Routine operation and maintenance expenses are estimated at $40,000 per year based on FERC data adjusted for automatic operation and conditions in Alaska. G-II-14 Chapter G-III PROJECT SELECTION AND OPERATION This chapter describes the selection of the stream regula- tion characteristics for the Gartina Creek Project and the type, number, and capacity of generating units. The selection of the Gartina Creek Project from among other possible sources of generation is discussed in Chapter G-IV. The operation of the Project in relation to power system loads is discussed in this chapter. Stream Regulation Characteristics The Gartina Creek plant will be a run-of-river hydroplant with pondage available for hourly regulation when streamflow is less than turbine discharge capacity. The area-volume curve for the Gartina Creek reservoir is shown on Exhibit G-4, 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 avail- able. 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 (77 cfs) divided by the power system capacity factor (0.45) or 171 cfs. The head on the project is calculated by assuming a reasonable height of dam which could be developed at the site. A 37-f£t high structure could pond water to El. 227 and develop an average net head of 72 feet. The total capacity available from the Project, assuming an efficiency of 85 percent would be as computed by the following formula: kW available = LT ote 72 Ses _0.8 ey, = 887 The number was rounded to 900 kW. G-III-1 To provide daily regulation of 900 kW, a storage volume of about 90 ac-ft would be required. This volume could be pro- vided with a drawdown of 7 feet from El. 227. If one half the capacity (450 kW) were installed, the maximum reservoir level should be at El. 222 to provide daily regulation. If no regulation were required, the maximum reservoir level could be set at El. 217. 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 a project to control inflow to meet hourly, daily, weekly or seasonal loads placed on the project. To determine the benefits gained from flow regulation, the energy from the Project, which would replace diesel energy, was computed for the following four cases: als 900 kW installed with regulation. 2. 900 kW installed without regulation. or 450 kW installed with regulation. 4. 450 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 G-4 Sheet 2 of 4) with the annual system energy requirements as obtained from the system load-energy curve (see Exhibit G-4, Sheet 3 of 4). The first year of project operation would be 1984 and the project would have a life of 50 years. Exhibit G-4, 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 analyses should be made at the feasibility level to determine the range of energy Output. The benefit cost analysis showed that adding daily regu- lation and installing 900 kW was justified only 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 450 kW was investigated and is selected as the installed capacity of the project. No daily regulation is provided; however a minimal amount (about 36 ac-ft) of storage will be available to regulate unit flow during low flow periods. G=Tik—2 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 than with a single unit. Each of the units will be of a "package-type" including a fixed blade propeller turbine. This type of unit is selected because of the suitable head on the Project and the low cost of this type of unit. In the feasibility study, more detailed analyses will be required to determine the most economical expansion program for the Project. Power and Energy Production The Project will provide replacement energy in the system. The Project will also be able to produce about 56 kW of power, 90 percent of the time. At the times when the water supply permits (about 25 percent of the time) the project will produce 450 kw. In the Project's initial year of operation it will supply 1850 MWh of energy, under average flow conditions, or about 60 percent of the system's requirements. The Project will be totally absorbed by the system in 1998, in which year it will produce 2170 MWh, or about 50 percent of the system energy requirements in that year. G-III-3 Chapter G-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 produced by this Project as by an alternative source of generation is taken as the benefit accru- able 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 as produced by the Project is 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 single 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 sytems, 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 section. The others are not as attractive for the reasons presented 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, requires 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 for relatively low tempera- ture heat has found increasing application in areas of the U.S. with abundant sunshine, which is not available in Southeast Alaska. G-IV-1 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 the case of the project under study in this report, its primary function is to supply energy to replace existing diesel generation. By applying load management and conservation measures existing loads could probably not be significantly reduced. Any slow- down 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 Juneau. Interconnection with that system would be impractical at pre- sent levels of technology due to the long transmission distance (about 36 miles), an ocean cable crossing, and the low level of consumption in the project area. Other Hydro The earliest published evaluation of hydroelectric power sites in Southeast Alaska was completed by the Federal Power Commision and the U.S. Forest Service in 1947 [1]. That study identified 16 sites on Chichagof Island. One of the sites was Gartina Creek. In 1977, Robert W. Retherford and Associates [2] completed an inventory study which identified the Game Creek site in addition to the Gartina Creek site. The Game Creek site was rejected because the river is an important andromous fish stream. The Retherford study selected Gartina Creek as being the most attractive project to serve Hoonah. Other creeks on Chichagof Island were studied briefly for this report, but were rejected either because of potentially significant adverse impact on salmon spawning or because of longer transmission distances to Hoonah. 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 equip- ment, would be about $1500 per kilowatt at September 1979 price levels. Adjusting the unit capacity down to 4-MW (the capacity which could serve the project area in the next 20 years), and adjusting for construction conditions in Alaska, would, conserva- G-IV-2 tively, double this cost to $3000 per kilowatt. At this capital cost, fuel (40% mosture) would have to be available at the wood- fired plant at cost of less than $19 per ton, and the interest rate could not exceed 9%, in order for the project to be more economical 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 speci- ally 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 project 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 contingencies and engineering. This cost would apply to the equipment 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 escalation. The capital cost of the biomass gas fired plant assumes the use of existing diésel engines and does not include the cost of the engine-generator set. The cost of wood in Hoonah 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 an equivalent moisture content (30 to 40 percent) and heat value, equivalent unit weight and adding transportation and handling cost gives a cost of about $55 per ton delivered in Hoonah. 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 Hoonah. 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. G-IV-3 The wood fuel costs presented in this analysis are at 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 Hoonah, partic-—- ularly since the town is contemplating a wood processing facility. 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 project 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 by gasoline. The price of $0.65 per gallon does not reflect the recent 24 percent increase in the reference price of Arabian light crude announced by OPEC in July. To reflect the short term upward pressure on the price of petro- leum fuels, a price of $0.80 per gallon is used as the base price of diesel oil in the present economic analysis. Fuel consumption in the project area averages 10.0 kWh/gal. which gives a fuel cost of $0.080/kWh. Economic Criteria Certain basic criteria are established for the economic analysis. These criteria define interest rates, fuel escala- tion 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. G-Iv-4 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 analy- sis is 50 years. In the analysis, costs and benefits are dis- counted to Jan. 1, 1980. The results of the analysis for this are shown on Table G-IV-1. For the purpose of evaluating the Project, a fuel escalation rate of 2 percent is recommended as being representa- tive of future trends. The benefit-cost ratios given on Table G-IV-l1 show that the Project is economically attractive at an interest rate of about 5 percent assuming 2 percent fuel escala- tion. Table G-IV-1 GARTINA CREEK PROJECT Benefit-Cost Ratios Interest Rate% 2 2 a 19. Fuel Escalation, % 0 0.89 0.67 0.56 0.47 2 Aer) 0.94 0.68 0.56 5 reels) aid, 1.08 0.83 Cost of Energy The cost of energy from the Project and the alternative is calculated year by year over the life of each project. The calculations are made assuming a cost of money of 2,5,7 and 9 percent and assuming differential fuel escalation of 2 percent. Normal inflation is assumed at 4 percent per year over the life of both projects. The annual cost of energy includes allowances for amortization, interest, operation maintenance, administra- tion, general expenses and insurance. Taxes were 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 tabulated, using a discount rate of 8 percent for present worth calculations. The results are shown graphically in tabular form on Exhibit G-5. As can be seen from the exhibit, the cost of energy from the Project is less than that from the alternative after 1988. G=-IV-5 Chapter G-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 frame- work should be developed as soon as possible to investigate financing alternatives. A feasibility study should be made of the Project and an Application for License should be filed with the FERC if acceptable financing can be obtained. A reconnaissance-level study should be made of use of wood either as fuel for direct combustion in a boiler to drive a steam 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 Hoonah and might also include a general study of the use of wood as a fuel for electricity generation on a regional and statewide basis. Organizational Framework and Financing THREA should be the implementing agency for the Project. THREA is the agency charged with power generation and distrib-— tion in Hoonah and most of the rural area of Southeast Alaska. THREA also has the possibility of obtaining low interest federal financing for the Project. The Alaska Power Authority might want to sé.ve 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 financing is available and wood-fired generation is not economically attrac- tive, the Project should be implemented as described below. G-v-1 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 an FERC license application. 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 deve- loped and 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 ecological data could be completed in one year's time. At that time a tentative decision on project feasibility could be made and financing and permitting arrange- ments 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. The Project would be classified as minor (less than 1500 kw) under current FERC regulations. The licensing process could be completed in about one year's time. Concurrent with the completion of the feasibility study an FERC application should be filed by re-arranging the material in the feasibil- ity study into license application format. 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 G-6. If organizational arrangments and the feasibility 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. G-V-2 \e Walibut Rack Inner Point sophia Re Hoonah Point/ VA WIARZA enaineenina COMPANY AUGUST 1678 ) Topesed by US, , Cx Service ) SN : in Axis ALASKA POWER AUTHORITY GARTINA CREEK PROJECT GENERAL LOCATION MAP EXHIBIT G-2. Max. Normal Foo! Top of bem Original Ground: el, eee Sound Rock SECTION OF DAM LOOKING UPSTREAM Scale O 20 40 Feet Se Li L. Concrete Powerhouse peed) Retaining Wall Crane 7.5 Ton Capacity we 10 el ee . { } Stee/ Column aa Support for Crane Generator Prefabricated (225KW) Superstructure GENERAL PLAN El. 225) 36" ¢ Scek O 20 40 Feet Butterfly Valve Fixed Blade Propeller ——— ‘ Turbine (3/6 Hp) Norma! H.W. é/. 2 Stee/ Pansteck— ra Fey Training Wall Creek Bottom Free Span Between PoP CCLRC "p 9p 3] 7.W. E/. (57 t ‘ WwW. . Anchor Blocks eee 3. poe B \ i werhouse a al £1157 ay W. EL /5/ SECTION THROUGH SPILLWAY Continuous Concrete Si// Support S ee Scale % é if Feet ~ POWERHOUSE TRANSVERSE Stiffener Ring Rock Backfill SECTION PROFILE ALONG PENSTOCK Temporary Scale O 4 Feet Stee/ Support Scak O 20 40 Feet [ER es aE El. 2028. — Original E/. 200% LW Ground’ 9 Aa Ne ee ene Original Ground: Retaining Wa// Cut is Ealga on fo Dip 1" $ Anchor Bars Tailrace| Planes so should not ] Reguiere Rock Bolts 6.0' Into Rock or 10.0" a ‘Along Penstock, Access Road y if Cut Back to OSH:1V 20 ALASKA POWER AUTHORITY GARTINA CREEK PROJECT SECTION B -B SECTION C-C SECTION A-A Scak 0 20 40 Feet Scale 20 40 Feet Scale © 4 ui nee e 2 eee GENERAL PLAN ¢ SECTIONS VAARZA erencenna commany avauet wre EXxH/BIT G-3 ESTIMATE HARZA ENGINEERING COMPANY CHICAGO, ILLINOIS _ tee Gartina Cresk Hydro ow Sepleniber [17 Tembe poge_L ot “J rages strucwre SUMMAry Estimated ovDdabracdghav creed ryoM Allen oo ITEM Quantity Unit Price Amount MOB ATIow | 00/000) 2 |LAND AND RIGHTS | % 00 R VOIR ARING c /S0|c00 4d \O/VERSIONS # CARE OF WATER [70|000 S |DAM, SPILLWAY 4 INTA | R27 J00 6 |WATERCONDUCTOR 332/000 MOWE P t (4 \600 op A f LECTEICH 0 UIP, 40 fo 4 |KOAD {441000 Ob | TRANSAUSE/OA | 22/000) ee | SUBTOTAL DIPECT CosT | | laselaod |_| bo GOO FOO 000 EXHIBIT @-3 ESTIMATE HARZA ENGINEERING COMPANY CHICAGO, ILLINOIS Project. Garth 14 Cr eek Hydre Date. - er 2 47 Page. 2 of 4 Pages structure Detailed Est. (Cone Dani Fo; } estimated by Checked pions — ITEM Quantity Unit Price Amount MOBILIZATIDID # CONST. SHHE Ls Oo} 09 2 (LAND 4 LAND LIGATS b = = keseryvorr = 20 Ac | [S00 3o| 680 bewerhouse $ Gons7. cite A 1006 DOO 13 Water-canducto; — 4 41 Co c | (~ G ROS — : 3Z3He / Subtets |= | 4 VO Nj hn G O —~ aN Gs INS G 4 4X oO Cc Cn (9 F E E ; el TET | Ni eB. CLEC N oO IO > |= a {2 af Ly DS O nh © C) a Se PR) Oy MIO Co cle 7 ON S~ =| SRB 2 20 4 Concrete Mass [SS0_CY| 300] Hes S Concreté Structural 3S cy | 350 2\25c 6 Ceme 6 260 cwrl_/4,10 88/266 7 keinforcing Ste 18 656 Les | ldo rola 6 Drai of leo 54 21640 00d ESTIMATE HARZA ENGINEERING COMPANY EXHIBIT G-3 CHICAGO, ILLINOIS Project Satfinn Ct ee ah ton Be CO epee ae a 4 = | smenre Detailed Est (Conc Dan Frey') Estimated by. hem | ITEM Quantity Unit Price Amount No. | © ATER CONDUCTOR | Stee! Fen lock x 35,006 LES Aso Supports ( £ 3 SREBRBIBG Le EXHIBIT 6-3 ESTIMATE HARZA ENGINEERING COMPANY CHICAGO, ILLINOIS hem ITEM Quantity Unit Price Amount i SHEN TRKANSHM/SS/04A 4 MM So42SO beg Mood Pole Frame 12.5 AE ST SA A, ve ie ie | a Ee URIS YELL cia (i | CT TE 00 iia iii ititiGa SattamMmi ete TM aM ee rc Ee TT AS RN in Sh A Me EAE oe ga NOT MAMMA AAA Me EXHIBIT G-4 IIT es elec ieee a Ti. ip E. THORL PROVES 7Ri CURVES. Raat ree 1 } ve ’ z t AW. WER EK SERVOIF ER -VOt ORE REA- 4 | eesteers 1, q ene fail { } 1 a. $<. eho ir ¥ eet { $ li _ Reserva Bag te. Aug WOlPNA/ ZT Ai iscbeebche h ORE a ieee farses tenes Scere peed is 4 peel one saad att to ate. ta +=. + } 4 fisiat + i poe f eats 1 Lae ' WORLaS Ry 1 feo POZA. ie Reg : : : i W Reg | eve 00 KW, t | 4 1 900 0 Ae eee j Ae ; 1 i L- afoot i i } poe ee { Seal i oa ray oe peers : Ee thet ts 3.0f 4_ EXHI/B/IT G -4 3 zi ro. Ep ergy Absorbed by Syste kdl pee aie | Ay v t es. Brees Bia Past ees bet $ jo % f99YS 2-9 LIGVINXZ te a eh sO algeien TLS ward? t ‘7. eat ye a ‘ beat ‘ eAalad pa rites tied espe joe faxr owe lof 9 EXHIBIT G-5 Sheet i i Ft fe ++ += os pf H4 au Bah tt _{ Ceeer tti4 Tr Se tt $4444 ++i T “phe toe “tf p+ a4 + tI ee 4 TI +4 I at +. COST CF MGNEVS REFERENCE DATE FIXED casts YEAR 1944 98s 19%6 1987 1988 1989 1990 HIS 1992 1993 1994 1995 1996 1997 1998 1999 2090 2001 2002 2003 2cou 2995 2906 anny 2008 2009 2010 2o't 2012 2013 20a 2015 2016 2017 2018 2019 2020 oat 2022 2023 2024 2025 2026 2027 2028 2029 2030 2¢31 2032 2033 145, 165, 185, 165. 185, 185, 185, 1AaS, 185, 185, 48S, 185, 145, 185, 185, 185, 185, 185, 185, 145, 185, 185, 145, 185, 18S. 185. 185, 185, 165, 18s, 185, 165, 185, 185, 185, vAS. 165, 145, 185, 185, 185, 145. 185, 165, 1865, 165, 165, 185, 165, 185. Oem costs USA 283, 295. 307, So. 332. 345, 3959/5 S736 3Aa, aos, 429, 43o, 4as4, 472, 491, Sio, 531. S52. 57a, $97, 621, 646, 072, 699, 727. 156. 786. Bi 7. a50, Sau, 919, 956, 994, 1034, 1075. 11968, LTS 1210, 1258, 1308, 1361. 1415, 1472, LSS tre AS9ere 1656, 1722. 79 1662, INFLATION RATES JANUARY 1980 GARTINA CREEK PROJECT 2040 TOTAL USBe UbBe ule as2e 504. Sl7e 530. So4e SoBe S73. 538. 695. 6ele 6359 6576 b7be 6956 T1b. 7376 7996 7825 A0bs a3te 8576 abuse 912. 9416 971e 19026 19356 1909. 11046 11416 1179s 12196 12606 1303, 13486 13956 1u436 1493. 15466 16006 1657.6 17166 17776 1a4dte 1907. 10766 20476 HYDRO FUEL ESCALATION RATES 2020 ALL COSTS IN $ 16606 ENERGY GENERATED Meld 1650, 1668, 1890, 1511, 193576 19555 1977, 2000, 20c2, 2045, 2059, 2092, ello, 2t4o, 2io4, 2179, 2170, 2170, 2170, 2170, 2170, 2170, é170, 2170, 2170, 2170, 2170. 2170, 2170, 2179, 2170. 2170, 2170. 2170, 2170, 2170. 2170, 2170, 2170, 2170, 2170, 2179, 2170, 2170, 21706, 2170, 2170, 2t70. 2170, 2170, cr CENTS/KWH 24,7 es, 25,4 25,7 2o,t 26,4 26,6 27,2 27,6 26,0 26,4 26,9 29,4 29,8 30,4 Suet 32,0 33,0 34,0 35,0 36,0 37,1 38,3 39.5 40,7 42,0 43,3 44,7 46,2 47,7 49,3 50.9 52.6 54,3 56,2 58,1 60,1 62,1 O43 66,5 68,8 71,2 T3387, 76,4 7941 €1,9 84,8 87,9 91,0 94,3 CUMULATIVE TOTAL 45é, 926. 1406, 1897, e4cl, 2916. 3448, 3991, 4549, 5Si22. S710, 6315, 6956, 7575.6 8232, e908, 9003, 10319, 11056, it81s, 12598, 13404, 14234, 15091, 15975, 16846, 17827, 18798, 19800, 20635, 21904, 23008, 241a9, 25328, 2oSu7, 27808, 29. 30460, 31654, 33297, 34791, 36337, 37937, 39593, 41309, 43086, 44927, 46833, 46809, 50856, PRESENT wKORTH 3il. 2956 289.4 2666 ence 239, 2276 216, 208, 1S) 185. 176, 106, 16906 S25 1456 138, 132, 1256 129, 1i4, 109, 104, 99, ose Gle 87, 63, 79, 76. Te. 69, 66. os, ol, 54, 56, 53, Sle 49, a7, aS, 43, ui, a0, 38, 36, 354 33, 32, OISCOUNT RATES ,060 CUMULATIVE Par, Site 607, BB, V1526 140d, 1643. 18716 26876 22926 QUT, 25726 2e49, 30176 31766 3329, 3u7a, 3ol2. 3744, 3809, 3989, 4103, 42126 U31b6 Gals, 45106 46016 OBIT, 47708 4649, 4925, 4997. S066. S132. S196. S2566 S3id, S370. 5423, SuTd, 5523. SS70e Solus Ses7e 565%. $738. S776. S812. S647, SQ61, 5913, 6 fo 2 4904S S-2 LIWHXI HARZA ENGINEERING COMPANY COSY OF ¥ONEY= REFERENCE DATE YEAR 1984 1985 1926 19387 194R 1989 1990 1994 1992 1963 1994 1995 1996 1997 1998 1959 2096 2004 2762 2053 200g 29495 21%6 2007 2008 2009 2nto 2o1t 202 2913 201g 2015 2016 2017 2018 2019 2020 2cey 2022 2ces 2024 2025 2026 2027 2028 2029 2036 20st 2032 2033 FIXED casts 322, 322, 322, 322, 322, 322, 322, 322, 32%, 322, bees See. 322, 322. 322, Scie 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, S222 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, 322, JaAnUARY Oe COSTS 273, 263, 255, 307, 319, 332, 345, 559. 373. Bea, 403, den, Uso, usa, 472, agi, Sia, S31. 552, S7a, 597, 621, ol, 672, 699, 727. 756, 78e. B17, aso, BRU, 919, 956, 904, 1034, 1075. 1118, 1163, 1210, 1258, 1308, 1361, 1415, 1472, 1531, 1992, 1656, 1722, 1791, 1862, INFLATION RATES RTI 2040 TOTAL 5956 6°56 617. 6296 o4te bSue 6576 6816 6956 Tlie 7256 W426 71586 7766 79ke alde 8326 A536 ATUe RVb6e 9196 G4de SOBs 9946 1o2te 10496 1078. 11086 1139.6 11726 12066 1241. 1278s 13tbe 13560 13976 14406 14856 15326 15606 14306 16836 17376 17946 1AS3. 1old. 19786 204d. 21136 2186 FEE mYDRO FUEL ESCALATION RATES ALL COSTS IN $ 1000 Cost OF ENERGY CENTS/Kwk ENERGY GENERATED Mad 1850, 1808, 1890, 1911, 1933, 1955, 1977, 2090, 2ce2, 20465, 2069, ecg2, allie, ei4o, erou, 2170, 2170, 2170, 2170. 2170, 21706 2170, Zi70, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 2170, 2170, 2176, 2170, 2170, 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2370, 2170, 2170, 32,1 32,4 32,6 32.9 23,2 33,4 33.7 34,0 34,4 3a,7 35,1 35,4 35,8 36,3 36.7 37,5 38,4 39,3 40,3 41,3 42,4 43,5 4G,6 45,8 47,0 48,3 49,7 Stef 52,5 54,0 55,6 57.2 58,9 00,7 62.5 64,4 66,4 63,4 70.6 72,8 7541 77,5 8041 82,7 85,4 88,2 914d 94,2 97,4 100,7 0020 CUMULATIVE TOTAL 595, 1290, 1617, 2cus, 3086, 3740, auo7, $087, S7B2, 6492, T2176 7959, 8717. 9493, 10287, 1i100, 11932, 12785, 13659, 14555, 19475, 1o41a, 17385, 16379, 19400, 20448, 21526, 22634, 23773. 24945, 2615i. 27392, 25670, 29985, 31342, 32740, 34160, 35066. 37197, 38777, G040B, 42091, 43628, useai, 47474, 493388, Sisee, 53409, 55522, 57706. OISCOUNT RATES PRESENT WORTH G05, 382, 360, 340, Bele 303, 28b, 270, 256, 242, 229, eld. 20S, 194, 184, 174, 105, 157, 169, 141, 134, 127. late 115. 110, 104, 99, 94, 90. 56, 82, 78.6 74, The 67. ou, ol. 59, So, 53, Si. 49, uy, 4S, 43, Ble 39, 37. 36, 34, 2080 CUMULATIVE Pow, GOS, 1866 Li4oe 1486, 18066 21095 2395, eceSe 29216 3162. 33916 3608. Bald. 4007. S191. 43cS. 45306 46387. UbSbe 4577, Sil2. 5239, 53006 S47be SSE5. S689, S788, 5883. SG73. 6058.6 O1406 62186 62926 6362. 64306 O49u, 65556 6614, 06706 O724.6 O77S6 68236 68704 0915.6 69576 6998, 70376 7075. T1106 T1456 6 YE £aayS 6-9 LIGIHX 7 HARZA ENGINEERING COMPANY COST OF MONEYS REFERENCE DATE = JANUARY YEAR 1984 IG 1946 1987 1998 1939 1999 1994 1992 19955 1996 1995 1996 1997 1998 12999 20%0 anny 20%2 2903 2004 2005 20% 2097 2908 2009 ec1o Pott 22 2013 2014 2015 2016 2017 2018 219 2029 ney 2022 2023 2024 2025 2524 2027 2028 2029 2036 2931 2032 2033 FIXED costs v3}, aS (35 Oem costs 273, 263. 25s, 307, 319, S326 365, 3S9i6 373. 3438, 4c3, ban, 43o, osu, 472, aot, 510, Sire 552. Sia. 597, 621, 646, 672, 699, 727. 7S6. Tin, Bi7. 850. Bau, 919, 956, 994, 1034, 1075, 1118, i163, 1210. 1258, 130A, {3o1. 1415, 1472, 15315. 1592, 1656, 1722. USS 1862, INFLATION RATES 2040 TOTAL 79N6 Tide T2660 7586 WSC. 7636 77be 7900 ROU. RIGs 3G eSt6 BOT. A8Se 903. g226 9416 9626 9836 1005 19286 10526 1nTTe 11936 11306 11586 1187.6 1ai7e 1r4He 12516 13156 13506 1387.6 14256 L46Se 15066 1549. 1594. Leste 16896 17396 17926 R466 1503. 19626 20236 2nb?e 21536 22226 22936 Seairicine aia ce 240 FUEL ESCALATION RKATE= 020 ALL COSTS Is 3 1000 ENERGY GENERATED Mak 1850, 1005, 1890, 1911, 1933, 1955, 1977, acco, 2n2e, 2045, 2069, 2c%e2, allo, 2140, 2164, 2170, 2179, 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 2170, 2170, 2170, 2170. 2170. 2170, 2170, 2179, 21706 2170, 217c, 2176, 2170, 2170, 2170, 2170, 2176, 2170, 2176, Cost OF ENERGY CENYS/KaK 60,6 62,2 63.9 65,7 67,5 69,4 71,4 73,5 75,6 77,8 80,2 82,6 e541 67,7 90,4 93.2 96.2 99,2 102,4 105,7 CUMULATIVE TOTAL 7WC4, tdi6, ayaa, 2481. Se3i, 4394, $170. $959, 6763, 7582, 6416, G2o7, 10134, 11019, 11922, 12644, 13785, 16747, 15730, 16735, 17764, 18816, 19892, 20995, 22125, 23282, 24469, 25686, 25934, 28215, 29530, 30880, 32267, 33692, 35157. 35664, 36213, 39806, 4iuuée, 43137, uus77, 46669, 48515, 50417, 52379, 54402, 50489, Sboul, 60863, 63156, PRESET nORTH 52. Ble 4S, 43. Gi, 39, 38, 36. CISCOUNT RATES ,080 CUMULATIVE Par, 679. eS eg 1353, 17516 2lebs 2u79, 25126 3120. 34216 37006 3903, G2l1e Uibbs UbOT, YETo. S074, S261. $438, Sedb. S7Tou, S91l4.6 O0Sb. C196 6319. 6440, 65558 6665.6 6768, Cb67, 69606 7049, 713d. 7T21d6 72916 7364, 7433, 74995 75626 76226 7679. T7336 17856 7835. 7862. 71927. 79716 60126 8051.6 6069. 6125. 640 & 4224S G-D 11A/HXTF HARZA ENGINEERING COMPANY COST OF 4ONEYS REFERENCE DATE YEAR 19Rq 19A5 1986 1987 1988 1989 1990 1994 1992 1993 19948 1995 1996 1997 1998 1999 2999 2004 2002 2003 2004 2095 2006 2007 2008 2009 2010 20it 2012 2013 2014 2015 2036 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2034 2032 2033 FIXED costs 548, 548, 548, 546, 548, S48, 548, 548, S46, 548, 58, 548, 548, sue, S48, 548, $46, 548, Sue, 548, 543, 548, 548, 546, 546, 548, 548, 546, $48, 548, 546, 548, 548, 546, 548, 548, 548, 548, 548, 548, 548, 548, 548, sue, S48, 548, 5468, 546, 546, 548, Om costs 273, 2a3, 295, 397, 319, 332, 345, 359, 373, 3B8, acs, 420, 436, 4Sa, 472, aot, S10. 531. 552. S74, 597, o2l. 646, 672, 699, 727. 756. 736, 817. 850, 8Bu, 919, 954, 994, 1034, 1075, 1116, 1163, 1210, 1258, 1308, 1361, 1415, 1472, 1531, 1592, 1656, 1722, 179%, 1862, INFLATION RATES JANUARY 14980 GARTINA CREEK PROJECT 2040 ToTaL Bele a3ie RUB. ASSe ROT. R806 A93e 907.6 9216 O3be OS16 SOBs. 984. 10026 10206 10596 10586 10796 1400. 1y22e 11456 14696 1194. 12206 1247. 12756 13046 13346 13656 13986 1u326 1uo7. 1504, 15426 1582. 1623. 166be 17lLe 17586 1806. 1ASb. 19096 19636 20208 20796 21406 2204. 22706 23396 24106 HYDRO FUEL ESCALATION RATES 020 ALL COSTS IN $ 1000 ENERGY GENERATED Man 1850, 18605, 4890, TS) 1933\5 1955, 1977s 2000, 2022, 2045, 2669, 2092, 2i16, 2140, 2164, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 2170, Cost OF ENERGY CENTS/KWH 44,4 44,5 44,6 44,7 44,8 45,0 45,2 45,3 45.5 45,8 46,0 46,2 46,5 46.8 OTe 47,9 45,8 49,7 50.7 SUT 52,8 53,9 55,0 56,2 57,4 58.7 60,1 61,5 62,9 64.4 66,0 67,6 69,3 Theol 72,9 74,8 76,8 78,9 81,0 83,2 85,5 88.0 90,5 93,1 95,8 98,6 101,5 104,6 107,8 DEP CUMULATIVE TOTAL 821, 1652, 24095, 3349, 4216, 5096, 5989, 6695, 7816, 8752, 9703, 10671, 11655, 12657, 136077, 14716, 15774, 16653, 17953, 19075, 20221, 21390, 22583, 23803, 25050. 26324, 27628, 28962, 30327, 31725, 33157. 34624, 36128, 37670. 39252, 40876, 42542, 4u2esa, coolt, 47817, 49e74, 51583. 535u6, 55565. 57644, 59784, 61968, 64257, 60596, 69006, PRESENT WORTH 556, S24, 492, 462, aya, 407. 383, 360, 339, 319, 300, 282, 2606 251. 236, 223, 210, 198, 187, 177, 167. 158, 149, 141, 134, 127.6 120, 114, 108, 102, 97. 92. 687. B3. 19. 156 The 68, 64, ol. 56. SS. 53. 50. 48, do, 44, ai. 40, 38, DISCOUNT RATES ,080 CUMULATIVE Paw, 558, 1082. 1574, 2036. 246%% 28776 3260. 3620. 3958, 4277. 4577. 4859, 51256 S376. Sola. S835. 6046.6 6244, Oust. 6608, O7T7Tbs 6934. 7083. 72256 7358. 7485, 76056 TT19. 7826. 7928, 8025. 8117. 8204, 8287. 83666 6441, 65125 85794 6643, 8704, 87036 BB18. 8871. 8921. 8969, FOU, 90584 90996 9139. 9177. 6 fo ¢ f274S GS-32 LIGHXZ HARZA ENGINEERING COMPANY COST OF MONEYS REFERENCE DATE FIXED YEAR costs 19AG 0. 1985 0. 1986 0. 1987 0. 1988 o. 19R9 0. 1990 Oo. 1994 0. 19990 oO. 1993 on 1994 0. 1995 ox 1996 OF 1997 on 199A 0. 1999 BA 2000 ae 2001 se 2002 Se 2003 5. 20048 Se 2005 Se 2006 OF 2007 5. 2008 5. 2009 Se 2010 S. 2011 5. 2012 S 2013 5. 2014 s. 2015 Ss 216 Se 2017 5. 2018 5. 2019 10. 2020 10. 2021 10. 2022 10. 2023 10, 2024 102 2025 10, 2026 10, 2027 10, 2028 10, 2029 10, 2030 10. 2031 10, 2032 10. 2033 10. 020 INFL JANUARY 1980 Oem ccsTs 204, 213, eet. 230, 239, 249, 259, 269, 280. 2Ft, 363, 315. B21. 340, 354, 365, 383. 398, aia, 431. wus, bo, oeu, Soa, Seu, 545, S67. 589, 613. 637, 663, 689, Vids 746, 176. 807, 639, 872. 907, Guu, 981. 1921, 1061. 1104, 1148, 1194, 1242, 1291, 1343, 1397, ATION FUEL cost 798, ales 227, pau, Pol, 2A, 300, %22, 05, 370, 397, 425, uS6, “ao, S24, 557. 590, 626, 663. 703, 745, 790, Aa37, B87, oul, 997, 1057, 1120, 1188, 1259, 1334, tai4, 1099, 1589, 1685, 1786, 1293, 2006, 2127, 2754, 2%90, 2533, 2685, 2A46, 3017, 3198, 3390, 3593, 3009, 4037, GARTINA CREEK PROJECT OIESEL RATE= 2040 TOTAL u02e UeSe U4Be utue 5006 529. 559. S916 6256 eole 699s 7406 783. R296 A7Be 9306 9786 10296 19826 143%. 11{98e 12016 13276 13966 14706 1547.6 16296 17156 180Se 1901. 20026 2109, 22216 23400 21656 25026 27426 28896 3n4de 3208. 3xb 16 35636 375be 39606 41756 Gu02e 4o4te UpBId. S1620 Sudde ALTERNATIVE FUEL ESCALATION RATE 020 ALL COSTS IN $ 1000 ENERGY GENE ATED Man 1850, 1868, 1890, 1911, 1933, 1955, 1977, 2000, 2022, 2045, 2ce9, 2092, 2ile, 2140, 2164, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 21706 2170. 2170. 2170. 2170.6 2170, 2170. 2170, 2170, 2170. 2170, 2170, 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 2170, 2470, 2170, 2170, 2170, 2170, 2170, Cost OF ENERGY CENTS/KAH 21,8 eee eS 24,8 25.9 27,0 28,3 29,5 30,9 32,3 33,8 S504) 37,0 38,7 40,6 42,9 45,1 47,4 49,9 $2.5 35,2 58,1 61,1 64,3 67,7 143 75,0 79,0 83,2 87,6 92,3 97.2 102,4 107,8 113,6 119,9 126,3 asso 140,3 147,68 155,8 164,2 L7Sai 182,5 192,4 202.8 213,9 225.5 237,9 250,9 CUMULATIVE TOTAL 402. 827, 1275, 1749, 2249, 2778, 3337, 3928, 4553, Sera, HOSS 6653, 7436, 8265, 9142, 10072, 11050, 12079, 13161. 14309, 15498, 16758, 18085, 19481, 20950, 22497, 24126, 25641, 27646, 29547, 31550, 33658, 35660, 36220, 40685. 43287, 40028, 48917, S1961, $5169, 58550. 62113, 65869, 69829, 74004, 76406, 83047, 679481, 93103, 98547, OISCOUNT RATES ,080 PRESENT WORTH 274, 268, 262, 256, 2506 245, 240. 235, 230, 225.5 220, 216, 2126 207, 203, 200, 194, 189, 184, 180, 175. 170, 166, 162, 158, 154, 150, 146, ide, 139, 135, 132, 129, 126, 123, 120, 117, 114, M11. 109, 106, 103, 101, 98, 96, 94, 92, a9, 87. 85, CUMULATIVE Par, 274, Set. 803, 1059, 1309, 1554.5 1794, 20295 2258.6 2483, 2704, 2920. 3idte 3339, 3542. 3742, 3936. 4125. 43096 4UB9, Ubbu, 4asa, 5000. Sie62. 53206 Suva, So2u, S770¢ S912. 60516 6186, 6318.6 Ou47, 6573. 6695. 6815S. 69326 10466 T1S7. 7206. 7372. 74U75. 7S76. T7674. T7710 7864, 79566 80464 6133, 8216. 6 40.9 fe7YS S-5 LIGVIHXF HARZA ENGINEERING COMPANY COST OF MONEYS .050 INFLATION REFERENCE NATE = JANUARY 1980 FIXED Oem FUEL YEAR COSTS costs cost 1984 Cc. 2n4, 198, 1985 0. 213, ale, 1984 0, eel. 227, 1987 0. esc. pau, 1988 On 239, aol, 1989 Oo. 249, 280, 1990 o. 259. 300, 1994 0. 269, 322, 1992 oO. 280, yas, 1993 0. 21. y70, 1994 0. 303, 397, 1955 On 315, “25, 1496 0. Selle 4S, 1997 0, 340, 669, 1998 o, 354, Sed, 1999 6. 36A, 557, 2000 6. 383, S90, anny eo. 398, 426, 2002 6. a 463, 2003 6. a3i, 703.4 2004 OB 44B, 745, 2005 &. 466, 790, 2066 6. 46a, 837, 20c7 &, So4. Ral, 200R 6. Sea. out, 2009 6. 545. 997, 2010 Gis 567. 1057, 2011 6. 589, 1120, 2012 6, 613. 1186, 2013 6. 637, 1259), 201g o. 663, 1334, 2015 eo. 669, tura, 2016 6. iis 1499, 2017 6. 746. 1589, 2018 6. 776. 1685, 2019 155 807, 1786, 2020 ise 839. 1R93, 20A1 13. 872. 200, 2022 13. 997, 2127, 2023 13, 94d, 254, 2024 15S 5 98, 2390, 2025 13. 1021, 2533, 2026 13. 1061, 2685, 2027 13) 1104, 246, 2028 13/5 1146, 3017, 2029 1S ie 1194, 3198, 2030 13, 1262, 3399, 2o3t 13, L293. 3593, 2032 13. 1343, 3A09, 2033 13. 1397, 4037, RATES GARTINA CREEK PROJECT olesel 2040 TaTal L022. U2Se UdBe ure S906 529. S596 5916 6256 bole 6596 746. 7436 ROGe BTA.s 9316 O796 10306 1083-6 14400 14994 12626 13286 13976 1u7%6 1548. 16306 17166 1R0b66 19402. 2003. 21106 2222s 234. 2ubbe 26056 27456 2RI26 30476 Balie 33846 35000 37596 39036 G,7Be 4u0Se GE4ue “RIT. 51656 Suste ALTERNATIVE FUEL ESCALATION RATES .020 ALL COSTS IN $ 1000 ENERGY GENERATED Mar 18S0, 1AoA, 1890, LT. 1933, 1955, 4977. 20006, 2022, 2045, 2069, 2092. elie, 2140, 2154, 2170. 2170, 2170, 2170. 2170. 2170, 2170. c170, 2170, 2170, 2170, 2170, 2170, 2170, 2179, 2170. 2170, 2176, 2170, 2170, 2170, 2176. 2170, 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2370, 2170, Cos? OF ENERGY CENTS/KaH 21.8 eer Cua 24,8 25.9 27,0 28,3 29.5 30.9 Sees) 33,6 35,8 S760) 38,7 40,6 42,9 45.1 47,5 “9,9 S25 5543 38.1 61,2 64,4 67,8 7163 7Set Tt 83,2 87,7 92,3 97.2 102,4 107,9 113,6 120,1 126,5 133,3 140,48 146,0 15S,9 164,4 V73c2 182,6 192,5 293,0 214,90 2e5,7 238.0 251,0 CUMULATIVE TOTAL 402, B27. 1275, 1749, 2249, 2776, 53376 3926, 4553. Seta, 5913, cosh, 7&3, 6265, 9142, 10073, 11952, 12062, 13165, 14305, 15504, 16765, 16093, 19490, 20966, 22508, 241368, 25854, 27060, 295625 31506, 35675, 35898, 38239, GO705, 43516. 4o0sd, USsIbb, 51993, 95204, 56588, o21sa, 65913. 69676, 74054, 78459, 23103. E5900, 93105, 98ol2, CISCOUNT RATES ,080 PRESENT wORTH 274, 266, 2625 256, 250, 245, 240, 235. 230, 225, 220, 216, 212, 207, 203, 200, 194, 189, 164, 160, 175, 17%. 166. 162, 155, 154. 150, 146, 143, 139, 135. 1S2ie 129, 126, 123, 120, 117. 114, tile 109, 106. 103, 101. 99. 96, 94, 92. 90. 87, 85, CUMULATIVE Pan, 27U, SU. 603. 1059, 1309. 1554, 1794, 20295 225B, 2483, 2704, 29206 Sissi 3339. 3542, 3742, 393be 4126. U3106 4490. 46656 4836, 5002, Siou, 55220 S475. 5625. S771. SOLU, 60536 6188, C3216 6449, 65756 6696.6 OB1B, 69356 7104S, 7160. 7209, 7375. TUTB. 7579. 76786 77746 7868. 7959, 8049, Bi 36, 6222, 6 Yo 2 faayS c-5 1/1FIHXI7 HARZA ENGINEERING COMPANY | } | | | | | | \ } | } GARTINA CREEK PROJECT nIESEL ALTERNATIVE COST OF MONEYS 4070 INFLATION RATES 2040 FUEL ESCALATION RATES 4020 CISCOUNT RATES ,080 REFERENCE DATE = JANUARY 4980 ALL COSTS In & 1000 FIXED Gem FUEL ENERGY Cost OF CUMULATIVE PRESENT CUMULATIVE YEAR costs costs cast TOTAL GEXEXATED ENERGY TOTAL nORTH Paw, Man CENTS/KWK 1984 G. 204, 196, 02s 1850, 21,8 402, 274, 274, 1985 0. ait, aia, u25e 1608, 22,7 827, 265, Sute 1634 0. 22t, 227, u4Be 1890, 23,7 1275, 262, B03. 1987 Oo. 230, pu, u7ue 1914, 24,8 1749, 256, 10996 1988 0. 239, Pol, 5006 1933, 25,9 2249, 250, 1309. 1989 oO. e4ua, 2B0, S29. 1955, 27,0 2778, 245, 1554. 1990 oO. 259, 300, 559. 1977, 28,3 3337, 240, 1794, 1994 oO. eho, 322, S916 2070, 29,5 3925, 235. 2629. 1992 0. 280. x45, 6256 2022, 30,9 4553, 230, 2255, 1993 0. 251, 370, bole 2055, 52,3 S214, a7, 2663, 1994 O. 303, 397, 6996 2069, 33,8 5913, 220, 270U.6 1995 0. 315, nas, 7406 2092, 35,4 6653, 2166 29206 1996 Oo. 327, uso, 7530 2116, 37,0 T4364 2126 31316 1997 O. za, 489, R296 2140, 38,7 8265, 2c. 3339, 1998 on 354, 524, R7Be alec, 40,6 9142, 203, 3542, 1999 Te Bea, 557, 9326 2170, 42,9 10074, 2006 3742, 2000 Te 38 3.. 690, 9806 2170, 45,2 110S4, 195, 3937.6 2001 7. 393, 626, Lo3te 2170, 47,5 12085, 190, W126. 2092 7, aia, 663, 1nBue 2176, $0,0 13169, 185, U3i16 2093 7, 443i, m3, 114.6 2170, 52.6 14310, 180, UU9t, 2004 Ts 4ua, 74s, 12906 2170. 55,3 15510, 175. U666, 2005 ita 4bb, 790, 12036 2170, 58,2 160772, 171. WE3T. 2006 7. 48a, az7, 13296 2.706 61.2 14101, 166, 5003. 2007 7. 504, a87, 13986 2170, o4,u 19499, 162, 5165. 2008 7. Sea, out, 1u72e 2170. 67,8 20970, 158, 5323, 2009 ite Sus, 997, 15496 2170, 71,4 22519, 156, SUTT. 2016 Te 567, 1957, Lodte 2170, 75,1 24150, 150, S627. 2011 7. 589, 1120, 1717. 2170, 79,1 25867, 1466, S773.4 2012 7. o13, 1188, 1807. 2170, 63,3 27674, 143, S91be 20t3 is 63), 1259, 1903.6 2170. 87,7 29577, 139, 60556 eota is 663, 1334, 2en04e 2170. 92,4 31582, 136, 6190. 2915 Ts 6339, tuid, 2116 2170, 97,3 33692, 132. o3236 2016 7. 717. 1499, 22236 2170, 162.5 39916, 129, 6452. 2017 7, 745, 1589, 2342. 2176, 107,9 362558, 126, 65776 2018 7. 77b. 1685, 2ue7. 2170, 113,7 40725, 123, 67006 2019 16, 807, 1786, 24086 2170, 120,2 43333, 120, 6F206 U) my 2920 Hy 839, 1293, 274B. 2170, 126.6 46080, 117. 6937, > < 2021 16, 872, endo, 2RIS6 2170, 133,46 48975, $14, 70546 % 2022 16, 907. 2427, 30556 2170, 140.6 52025, Yil. 7163.6 % x= 2023 16, gua, 2254, 32hue 2170, 148,41 55239, 109, 72726 “RK b&b 2024 16, 981, 2390, 3876 2170, 156.1 58626, 10%. T37Ay = 2025 16, 1021, 2533, 3569. 2170, 164,5 62195, 104, TUBS. Oo NY 2026 le, 1061, 2685, 37626 2170, 173,4 65957, 10l. 7562, 2027 16. 1104, 2Rub, 39666 2170, 162,8 69923, 99, 76816 9 L) 2028 16, 1148, 3n17, WyBte 2170, 192,7 75104, 96, T7776 2029 16, t1a, 3198, 4408. 2170, 20341 78542, 94, TEs | 2030 16. 1242, 3390, “eure 2170, 44,2 83159, 92. 79636 \o 2031 to, 1291, 3593, 4900. 2179, 225.8 88059, 90. 8052. 2032 1o, 1343, 3R09, 5168. 2170, 238,1 93227. 87, 8140, 2033 16 . 1397, 4037, Su50. 2170. 25i,t GO677, &3S, 82256 HARJFA ENGINEERING COMPANY COST OF MONEYS REFERENCE DATE FIXED YEAR costs 1964 1985 1984 1987 1928 1989 1999 1994 1992 1993 1994 1995 1996 1997 1998 1999 ann 2051 2002 2003 2004 2905 20%6 20907 2008 2009 aoto 2041 2012 2013 2ota 2015 2016 2017 2018 2019 a. 2020 172 2001 17. 2022 i. 2023 17, 2024 17. 2025 17, 2026 17. 2027 173 2028 17. 2029 17. 2030 17. 2031 17, 2032 17. 2033 17. MOBOBMBBMHBMMHGAHSHBBBBHDOOCDTC®FDDDDDFD9DDO00 090 JANUARY Oe costs 204, 213. 22. 230. 239, 249, 259, 269, 280, 21. 393, 315. 327, 340, 354, 364, 33, 398, 414, 431. aaa, dob, 4b4, Soa, Sea, 545, 5e7, 569, 613, 637. 663, 69, 717, 746, 776, 807, 839, 872, 907, Qua, 9B1, 1021, 1061, 1104, 1146, 1194, 1242, 1291, 1343, 1397, INFLATION RATES 1980 FUEL cosT 198, P12, 227, pu, Pol, 2ao, 200, Bee, 345, X70, x97, G25 a5o, wad, S24, 557, 590, 626, 663, 703, 745, 790, R37, ART, gai, 997, 1057, 1120, 1184, 1259, 1334, tars, 1499, 1589, 1685, 1786, 1893, 2006, 2127, 2254, 2390, 2533, 2685, 2QRUb, Sate, 3198, 3390, 3593, 3RO9, 4037, GARTINA CREEK PROJECT nTESEL 2040 TnTal ul2e u2Se adBe ulus S008 5296 559. 5916 6256 O16 BIG. THO. 783. R296 RTBe 9336 Oates 10326 10856 11426 12916 1po4s 13306 13996 1uT3e 15506 16326 1718. LROB. 1904, 2005e 24126 22246 23436 2uS8. 299% 2749. 26960 3n516 32156 3388. 35706 37636 3967. 61826 “u09, GH4Be 4Q01e 51696 SuSte ALTERNATIVE FUEL ESCALATION RATES ,020 ALL COSTS In S&S 1000 ENERGY GENERATED Man 1656, 1868, 1899, 191%, 1933, 1955. 1977, 2000, 2022, 2045, 20a9, 2092, 2116, 2140, 2164, 2176. 2170, 2170, 2170. 2170, 2170, 2170, 1 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170. 2170, 2170, 2170, 2170, 2170, 2170, 2170, 2170, Cost OF ENERGY CENTS/KAH 21,8 22,7 23,7 24,8 25,9 27,0 28,3 29,5 30,9 32,3 33,8 35,4 37,0 36,7 40,6 43,90 45.2 47.5 50,9 52.6 55.3 58,2 61,3 64,5 67,9 71,4 75,2 79,2 83,3 87,8 92,4 97,3 102,5 108,0 113,7 120,2 126.7 133.4 140,6 148.1 15641 {64,5 173.4 182,8 192,7 203,2 214,2 225,9 238,2 251,2 CUMULATIVE TOTAL 402, 627, 1275, 1749, 2249, 2778, 3337, 3928, 4553, Seta, S915. 6653, T4360, 8265. 9142, 1007S, 11056, 12088, 13173, 14515, 15516, 16779, 16109, 19508, 20980, 22530, 24162, 258680, 27688, 29592, 31596, 33709, 35954, 38277, 40745, 43354, 46102, UB99B, $2049, 55264, 56o52,. 62222, 65985, 69952, 74134, 78543, 63191. 86092, 93261. S8712. OISCOUNT RATES ,080 PRESENT WORTH 276, 265, 262, 256, esc, 245, 260, 235. 239, 2256 2294 eto, 212, 207, 203, 265, 195. 190, 165, 180, 1756 17he Loe. 162, 158, 154, 150, 146, 143, 139, 136, 132, 129, 126, 123. 120. 117. 114, {1t. 109, 106, 104, 101. 99, 96, 94, 92, 90, 87, 85, CUMULATIVE Pay, 27k, S4t. B03. 1059, 1309. 1554, 1794, 2629, 2258.5 28%, 2704, 2520.6 Site 3339, 3542. 3742. 3937. 4127, G312. 4U92, U6O7. UB3B, S00u, S167, 5325. Su79. 5629. S775. S918. 6057. 61936 6325. 6USu, 65806 67026 6822. 6939, 7054, 71655 72746 7380. 7TUBu, 7585. 7083, 7780. 7874, 79656 8055S. 8143, 8228, 6 0 6 4204S g-£ LIGIHXF HARZA ENGINEERING COMPANY EXHIBIT G-6 Preconstruction Activities Organization, Land Selection and A/ternative Study Feasibility Study Provisional Final Environmental] FERC License Application Preparation Review Other Permits Fi inancing Design,Contract Documents & Award Construction Mobilization Quarry and Stripping Diversion Darn Penstock Powerhouse Turbines ahd Generators Transrission Testing and Commissioning ALASKA POWER AUTHORITY GARTINA CREEK PROJECT IMPLEMENTATION SCHEDULE WARZA EnsiINcERING ComPaNy - AUGUST 1979 Appendix G-A GEOLOGY Regional Geology General Formations of Southeast Alaska vary from Lower Ordovician volcanics (in some places depositied in marine environments) and cherts to poorly consolidated recent glacial (fluvioglacial 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 black shales, cherts and limestone, (or their metamorphic equivalents e.g. slates and marbles). Volcanism, which is still present, has occurred intermit- tently since the early Paleozoic. This is evidenced by basalt or andesite volcanic flow rocks, or welded tuffs in unmetamor- phosed 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, greenstones, slates and marbles. Bedding is often difficult to differenti- ate from foliation in many of these sequences. In addition to the regional metamorphism, aureoles, or zones of contact meta- morphic 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 Pennisula. As such, it is a broad belt of interconnected ranges that has been subjected to several episodes of folding and faulting and plutonic intrusions. G-A-1 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 line 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 classical concept of thrust faulting extending to substantial depths. Earthquake foci increase in depth as distance from the oceanic trench increases. Master faults, primarily strike-slip in character, account for much of the seismic activity of Southeast Alaska. These faults, shown on Exhibit G-A-l, occupying and bounding the Coast Range orogenic belt, can 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 10, 1959. This movement was at least 70 feet laterally and 21.5 feet vertically. 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 fault. (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 G-A-2 the fault; however, the Denali-Chatham Strait Fault is long and 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 earthquakes can be the formation of seismic sea waves or tsunamis. Generally these 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 overridding 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. G-A-3 Retreat of glaciers occurred approximately 10,000 years ago, a short period of time from a geological standpoint. 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 part of Gartina Creek apparently fol- lows the valley formed by a valley glacier; and (2) The lower part is in an area of poorly integrated drainage systems which are apparently composed of rock and till drumlins and in places covered by ablation moraines. 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, thus attesting to the commonness of these pheno- mena. Bent thee trunks on some slopes indicate creep movement and potential instability. In general, debris avalanches occur on oversteepened 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 G-A-4 generally parallel to the surface and which appear to have been formed as a result of relief of stress following melting of glaciers. Triggering mechanisms can be large increases of soil mois- ture due to rain or disruption of drainage due to construction activities, logging, or other activities that remove vegetation. Earthquakes also can trigger debris avalanches. Rock falls from cliffs are one of the mass wasteage pheno- mena. Good engineering practice will eliminate hazards to pro- jects 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. Gartina Creek Geology Physiography During Late Pleistocene the low lying parts of Chichagof Island, including the lower parts of the Gartina Creek drainage area appear to have been carried by ice fields, and tide water glaciers. Within this area drainage systems are poorly defined. Higher parts of the island, including, the upper parts of the Gartina Creek drainage area appear to have protruded through the ice field. Valleys in this area have the typical "U" shape depicting their glacial origin. Following melting of ice fields and removal of their loads, the local area tended to rebound with the result that streams (Gartina Creek) commenced eroding their courses headward. The falls on Gartina Creek is one of the manifestations of this headward erosion. The falls is located in an area of hard nearly vertically dropping andesite beds or layers. Downstream of the falls, the creek has eroded a shallow gorge with steep sides. Upstream of the falls the valley appears to be wider, with more gentle slopes. The entire area is heavily forested. Seismicity The location of the site on Chichagof Island, which is be- tween the Chatham Strait Fault and the Fairweather Fault, indi- cates that the area is seismically very active. G-A-5 In addition to these major faults, numerous faults, gene- rally paralleling the Fairweather Fault, pass through Chichagof Island. These faults, referred to in the literature as the Tenakee Fault system, are generally considered to have not had a strong effect on the present day overall geologic situation. One of these faults, the Freshwater Bay Fault is considered to cross Gartina Creek approximately one mile downstream of the falls. Geological Investigations Work by the USGS is reported on in Professional Paper 792, Reconnaissance Geology of Chichagof, Baranof and Kruzof Islands, Southeastern Alaska, by R.A. Loney, D.A. Brew, L.J.P. Muffler, and J.S. Pomeroy (1975). The nomenclature established in this Professional Paper is used in this report. ‘The area was visited by Harza personnel in July 1979. Site Geology Rock at the falls and at the damsite which is approximately 120 feet upstream of the falls, consists of basalts and welded tuffs belonging to the Devonian-Freshwater Bay Formation. At the Project site and the falls, the rock is a layered or bedded, dark grey, finely crystalline, hard andesite. Layers are generally about 1 foot to 3 feet thick. Downstream (approx- imately 100 feet) from the falls, dark grey welded tuffs are found. The results of petrographic analysis of rock samples from the site is given in Exhibit G-A-2. At the falls and the site layers strike N80W to N70E and dip 70° to 90° respectively. Downstream of the falls the dip flattens to about 45°S. Prominent joints, apparently stress relief joints related to removal of glacial loads occur near the base of the falls. These strike N70E and dip 15° to 25°S. Engineering Geology Dam, Spillway, and Penstock Intake. Stripping of the dam should remove all soil and loose rock. The bed of the channel is in part alluvial sands and gravels and in part rock outcrops. It is estimated that average strip- ping for the dam would be 3 feet in this area. G-A-6 A thick (approx. 10 feet) vertical ledge of andesite out- crops to a height of 20 feet on the east side of the channel. Minimal stripping (approximately 3 feet) should be sufficient for this part of the abutment. About the area outcrop of this ledge, it is recommended that stripping on this abutment be 5 feet. No outcrops were observed on the west abutment; however, it is believed (from the irregularities of the abutment topography) that bedrock occurs at a shallow depth. For cost estimating it is recommended that a depth of 5 feet be assumed for stripping. Open joints and zones of severly broken weathered rock and/ or clay should be cleaned and backfilled with concrete. The grout curtain recommended requires vertical holes to 10 feet depth to extend up both abutments to the elevation of the reservoir normal water level. Penstock. Penstock supports should be founded on rock. Bend anchors at concave bends sould be securely anchored into bedrock. It is recommended that these anchors be 25 foot long posttensioned tendon type anchors. Powerstation. The powerstation should be located on the edge of a pool formed by the waterfall. Bedrock in this area is shallow and little difficulty shold be encountered in founding the plant on bedrock. Protection of the plant from raveling of steep slopes should be incorporated into design. This protection should consist of scaling the slopes and then installing rock bolts and wire mesh. Proposed Exploration Dam, Spillway and Penstock Intake. It is recommended that 5 drill holes totaling 250 feet be drilled. All should be in- clined 45°, two to cross beneath the channel with one hole dir- ected under the east abutment, and two drilled into the west abutment. Penstock. One inclined 50 foot drill hole should be drilled to the south near the anchor block for the concave penstock bend. Powerplant. One drill hole 10 feet deep should be drilled at the powerplant location. G-A-7 EXHIBIT G-A-/ Black Bear Lake Gunnuk Creek Q) Cathedral Falls Creek Gartina Creek Thayer Creek uims Creek LEGEND: \ of Epicenter of earthquake, number of events ——---Fau/t, dotted where concealed of interred. > » - * Were: LOCATIONS OF FAULTS =, wae AND WIARZA encineerinc company. AUGUST 1579 ALASKA POWER AUTHORITY Only earthguake of 3.0 + magnitude or I+ intensity are shown. EARTHQUAKE EPICENTERS Exhibit G-A-2 PETROGRAPHIC INVESTIGATION OF SAMPLES FROM THE ALEXANDER ARCHIPELAGO, S.E. ALASKA. A.F.Koster van Groos Gartina Creek, top of falls Macroscopic: green-grey fine-grained rock, calcite in fractures Microscopic: Rock is composed of chlorite, epidote and some quartz, the rim is leached. No chert seen the material is strongly altered. Conclusion: Possibly strongly weatherd basalt, Low temperature i metamorphism Gartina Creek, at damsite, 120 feet upstream Macroscopic: green, finegrained dense rock, some fractures filled with white material Microscopic: green chlorite, all layered. the chlorite crystals all have same orientation, chert and epidote in cracks Conclusion: Probably sedimentary origin, extremely chlorite “ich. Conclusions: All the samples from the Alexander Archipeléso secm 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, quarez,| or calcite. The degree of alteration is often substancial, eSpecially when the original rock is of volcanic origin Appendix G-B HYDROLOGY Climate 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. Temp eratures The maritime influences cause temperatures to be mild and uniform. The occasional incursions of continental air cause considerably colder temperatures for short periods. Exhibit G-B-l shows average and extreme temperatures for a climatolog- ical 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 qua- drant. In addition these southeasterly winds bring rain a far greater percentage of the time than do winds from other qua- drants. Therefore, southeastern exposure is an important factor in the precipitation pattern, and hence runoff, of a project area. (Gartina Creek is an exception to this general rule). In latitudes south of the project area, the cyclonic cir- culation results in the prevailing winds being from the south- west. Therefore, moisture from warmer seas is carried ina generally northward direction, passing over cooler water, there- by lowering the air temperature. This, along with cyclonic convergence and local orographic effects, produces copious rainfall with large variations over short distances. Precipi- tation, 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". Storms tend to be general and for extended periods. In- tense precipitation of the thunderstorm type is very rare, and is never nearly as intense as in warmer climates. This leads to very much smaller flood peaks in small basins than are found in warmer humid areas. Flood volumes, however, can be large. Precipitation data for a climatological station in the project area in Exhibit G-B-l. Streamflow Streamflow data are far more extensive in the project area than are precipitation data. Streamflow data integrate the conditions for the entire drainage basin about the gage. Therefore, 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 T-B-2, indi- cate 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 area covered herein generally has 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. The resultant rate of increase in unit runoff is 0.003 cfs per square mile for each foot of additional average basin eleva- tion. 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 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 G-B-2 elevation and a partially subjective factor is applied to adjust for the effectiveness of the spillover. Mr. Robert Cross, Administrator 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 is considered in estimating 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 G-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 predominant 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 lcation 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 is used without adjustment. Records were available only for 1977 for several stations. Comparing the 1977 runoff with long G-B-3 term runoff for stations having long records indicates that 1977 was fairly representative of the long term average with 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, as 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 computed by planimetering 1:63,360 scale or 1:250,000 scale topographic maps. Basin elevations are obtained 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 intersec- tions. There is a gaging station on Hasselborg Creek about 21 miles to the east of the Gartina Creek site having fairly comparable runoff. The station has 23 years of record (1956 to present). This station has an average runoff of 6.67 cfs per square mile. Using the grid system on a 1:250,000 scale map gives an average basin elevation of 980 for Hasselborg Creek. The Gartina Creek basin averages about 1260 in elevation. Using 0.003 cfs/sq. mi. increase in runoff per foot of elevation gives 0.003 (1260-980) or 0.84 cfs per square mile increase for the basin or a total of about 7.5 cfs per sq. mi. For the drainage area of 10.3 sq. mi. the average flow is 77 cfs and the mean annual flow volume is 929 cfs-months. The average annual flow is then distributed over the year in accordance with the seasonal relationships shown on Exhibit G-B-2 to arrive at average monthly flows. Average monthly flows are shown on Table G-B-l. G-B-4 Table G-B-l AVERAGE MONTHLY INFLOW AT GARTINA CREEK Month Inflow, cfs January 29 February 46 March 33 April 65 May 159 June 136 July 59 August 40 September 86 October L332 November 95 December 49 Annual Average 77 Flow-Duration Computations Computer printouts of daily flow were obtained from the U.S. Geological Survey for Hook Creek near Tenakee on Chichagof Island. Hook Creek has a drainage area of 4.5 sq. mi, an average basin elevation of 1240 ft. and a unit runoff of 6.2 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, irrespec- tive of season of occurence 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 Gartina Creek is shown on Exhibit G-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. G-B-5 By substracting the PMP for consecutive durations, incre- mental precipitation is derived for each 6 hours for the 3-day storm period. These are maximized sequentially (placing the 12 6-hour values in the most critical sequence). The highest increment was 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 ina 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 G-B-2 and the PMF hydrograph is shown on Exhibit G-B-3. Table G-B-2 PROBABLE MAXIMUM FLOOD SUMMARY Drainage Area, sq. mi. a (0) is) Flood Peak, cfs 7,850 Food Volume, cfs 130000 Creager's "C" 26 Other Hydrologic Factors Other hydrologic factors that are briefly noted but not studied in detail were evaporation and sediment. Evaporation Evaporation losses are small and already 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 inundated. 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 I7 Gartina Lake inflow, routed outflow is discussed in Chapter G-II. G-B-6 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. G-B-7 JAN FEB MAR APR MAY AVERAGE TEMPERATURE 26.5 28.3 32.5 39.2 46.3 HIGHEST TEMPERATURE 54 55 53 70 81 LOWEST TEMPERATURE -25 -16 -13 4 23 AVERAGE PRECIPITATION 4.65 2.99 2,91 2,52 2.84 AVERAGE SNOWFALL 16.6 12.2 11.0 1.1 0.3 . JAN FEB MAR APR MAY AVERAGE TEMPERATURE 29.2 31.0 34,8 40.0 47.9 HIGHEST TEMPERATURE 48 50 52 465 79 LOWEST TEMPERATURE -3 ‘4 13° 146 25 AVERAGE PRECIPITATION 5.07 3.87 4,32 3.29 AVERAGE SNOWFALL - Harza Engineering Co., Aug. 1979 2.72 GUSTAVUS JUN JUL AUG SEP OCT ‘NOV DEC ANNUAL 52.3 55.4 54.3 49.7 42.1 34.2 29.1 40.8 83 86 87 73 +65 57 56 87 29 33 25 23 13 -6 -17) (+25 2.28 4.00 4.10 6.84 8.96 6.70 4.96 53.75 0 0 0 T 0.7) 7.0 17.2 66.1 TENAKEE JUN JUL AUG SEP OCT NOV DEC ANNUAL 53.7 55.7 56.2 52.0 43.3 33.6 30.3 42.3 83 82 82 78 60 54 44 83 33 360—Cfsi37—'—i‘<i‘C2stiatié«iW 2. 2.48 5.87 63.20 4.71 4.66 7.75 11.28 7.18 Alaska Power Authority Gartina Creek Hydrologic Data L-d-9 FLqLYxXg TAKATZ CREEK PROJECT RUNOFF ~ ; and : PRECIPITATION DISTRIBUTION 8 \2 Tokotz Cr. 7 Green Ll. Outlet 6.Sowmill Cr, | 3. Boranof R. AN DRAINAGE AREA ELEV.& PREC.GAGE ELEY, FT. nN ' ° May& June WEIGATED M ie November @ April Period July& October 5. Baranof (Precip) oa O15 20 30 ao 50 60 70 0 RUNOFF or PRECIPITATION 5 PERCENT of ANNUAL NOTE: 1-5 On eastside, 6-9 on westside of Island. © November- April © May-June 8 July- October APA Dewo fo, 1113-905-20 EXHIBIT G-B-3 eee ee ech Peay ATE he Bi ! hop HORITY. EST "| REEK Prove oF ‘POWER A Appendix G-C ENVIRONMENT Summary The potential environmental effects of the Project are identified and mitigating actions are recommended. Permit requirements are analyzed and requirements presented for additional data. The principal environmental review agencies for the pro- ject will 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 avail- able, these agencies do not perceive any critical environmen- tal issues which would preclude project development. Addi- tional environmental data will be required, of course, and the project will be subject to the federal, state, and local environmental review and regulatory process. Immediately downstream of the project site there is a waterfall which is impassable to fish, so no fish passage facilities will be required. Magnitude of Potential Impacts Potential impacts on migratory salmonid populations down- stream of the project will probably be minimal and could be further reduced by proper project design and operation. Loss of wildlife habitat, effects on visual esthetics, and other impacts due to project access road and transmission line construction will be minimal if the proposed logging roads are used for project access and transmission routes. Reservoir clearing and inundation will eliminate some wildlife habitat. The principal impact of dewatering the falls will be on visual esthetics. Recommendations The U.S. Forest Service and Alaska Department of Fish and Game should be asked to assist in assembling the ecologi- cal data required to determine potential project effects in greater detail. These agencies should also be kept advised of refinements in project concepts and design so their input can be included as planning proceeds. Other agencies with major review and/or regulatory respon- sibilities should also be contacted. These agencies are listed in the main report. G-C-1 Environmental Reconnaissance Gartina Creek Site Location and Land Ownership The project will be run-of-the-stream and will provide forebay daily storage only at a dam located in Section 11, T44S R61E, Copper River Meridian, Alaska. The site is located on U.S. Forest Service (USFS) land in the Tongass National Forest in Value Comparison Unit (VCU) 205 of Manage- ment Area C31 (USFS 1979). VCU 205 has been assigned a Land Use Designation (LUD) of IV in the Tongass Land Management Plan (USFS 1979). Water and power developments, utility corri- dors, and permanent roads are permitted on LUD IV lands in the Tongass (USFS 1975, 1979). The tract of National Forest land on which the project would be located is bounded on the north, south, and west by land selected by native corporations, including Huna Totem, Inc. (USFS 1979) Project Area and Natural Resources Lakes and Steams. There are no lakes in the drainage basin. Garti aya ya Creek | passes over a waterfall impassable to anadromous fish approximately 2.5 miles above the intertidal zone. The proposed dam will be located about 100 feet upstream of the falls. The mouth of the creek is a wide alluvial fan with numerous sloughs and extensive intertidal zone (ADFG-DCF no date). Vegetation. 3yhe vegetation in the watershed is typical of spruce- =hemlock= coastal forest. There has been no logging in the project area, but survey crews are now laying out logging road routes. One of the roads will pass within 0.2 miles of the proposed damsite. Wildlife Resources. Wildlife in the project area is expect- ed to be generally representive of Chichagof Island species. Larger Chichagof mammals include brown bear and Sitka black- tailed deer (Clark and Lucas 1978). 1/ Acronyms are listed in Exhibit G-C-l 2/ Anadromous fish are those that spend some part of their life in salt water and return to fresh water to spawn. 3/ Scientific names of flora and fauna mentioned in the text are listed in Exhibit G-C-2. G-C-2 Most of the more than 200 bird species common to south- eastern Alaska are expected to occur on the Island (Clark and Lucas 1978). A duck tentatively identified as a harlequin duck was observed at the waterfall below the project site. Fisheries Resources. Gartina Creek is catalogued as an anadromous fish stream (No. 114-31-009) (ADFG 1975) and is known to support spawning runs of pink and chum salmon (ADFG-— DCF no date, Ingledue 1979) and coho salmon (USACE 1976). Alaska Department of Fish and Game (ADFG) escapement— counts show peak escapement during the last 20 years of 8,500 chum in 1964 and 1,500 pinks in 1971 (ADFG-DCF no date). The peak of the spawning run (early summer chum) usually occurs in July (Ingledue 1979). Pink and chum salmon spawn primarily near the mouth of the stream (ADGF-DCF no date) at least 1.5 miles downstream of the proposed project damsite. No information was obtained on resident fish. More in- formation needs to be obtained relative to spawning and fish movements. Endangered and Threatened Species. The only fish or wildlife species listed by the U.S. Fish and Wildlife Service 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 are expected to pass through the general project area only infrequently and the project should have no effect on them. Potential Project Impact and Mitigation Measures Access Roads and Transmission Lines. The site will be accessible by road from Hoonah once logging operations in the area are begun. The road could also serve as the transmission line route. A small amount of wildlife habitat may be lost by extending the road to the project site. Proper construction procedures will minimize runoff of sediment to the stream. Deposition of fine sediments can be harmful to fish eggs and juveniles. Construction of Dam and Generating Facilities. The waterfall immediately downstream of the damsite is impassable to fish, so no fish passage facilities will be required for the project. Proper precautions should be taken during construction to avoid runoff of large amounts of sediment to the stream. Blasting and other noise may cause wildlife to temporarily abandon the area, but the animals should return once construction is com- pleted. Provisions will have to be made to pass adequate 4/ Number of adult fish returning to spawn. G-C-3 stream flow during construction so that downstream aquatic habitat is maintained, particularly during the salmon spawning and rearing season. Some clearing will be required in the reservoir area. Clearing and inundation will eliminate some wildlife habitat. Operation. The reservoir will have daily storage capacity only, so that effects on general water quality downstream are expected to be minor. Downstream water temperatures and dissolved oxygen concentrations might be slightly changed, depending on the level of the reservoir from which water is withdrawn and on water retention time in the impoundment. Small changes in water temperature and dissolved oxygen at the project site will probably not significantly affect the prin- cipal salmon spawning and rearing areas in the intertidal area near the mouth of the stream. The natural stream discharge regime will probably be only slightly modified, but project operation might have to be adjusted at times to provide adequate downstream flows for salmon. The falls will be dewatered part of the time, but this will not affect fish populations. Harlequin ducks, if present, might be displaced since their feeding and nesting habitats are linked with waterfalls. The principal impact of dewatering will be on visual esthetics. 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. USFS would prefer to have hydroelectric developments located en- tirely on private or tribal corporation lands to avoid the neces- sity of processing a Special Use Permit application, and an ex- change of National Forest and tribal land for such purposes would be looked upon favorbably (Brannon 1979). This does not appear to be applicable to the Gartina Creek Project because there has been no interest expressed in acquiring the site by the local native corporation; Hunatotem, Inc. The project would then have to be licensed by the Federal Energy Regulatory Commission (FERC). The project will be in the minor project category (Less than 1.5 MW installed capacity), and the application for license will have to include the following (FERC 1978): Exhibit K. Definition of project lands and boundaries. Exhibit L. Description of project structures and equip- ment. Copies of necessary federal, State of Alaska, and local permits, approvals, and certifications. Applicant's Environmental Report, including: ‘Fe Description of project and mode of operation, ee Description of the environmental setting, SG Description of expected environmental impacts and enhancement and mitigation measures, 4. Description of project alternatives, including alternative sites and sources of energy, and Se Description of consultations with federal, State, and local agencies during preparation of the environmental report. The information required for this report should commensurate with a preliminary environmental assessment to determine the need for an Environmental Impact Statement. Whether or not a USFS Special Use Permit and a FERC license is required, the following federal permits must be obtained: aS 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. AG U.S. Environmental Protection Agency (USEPA) - Section 402 FWPCA National Pollutant Discharge Elimination System (NPDES) permits for point source discharges. Construction phase and powerhouse slump 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. Other federal agencies which would probably review a FERC license application and the applications for other federal permits include U.S. Fish and Wildlife Service, National Marine Fisheries Service, USFS, 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. G-c-5 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. Department of Environmental Conservation - Certifi- cate of Reasonable Assurance for Discharge into Navigable Waters (in compliance with Section 401 of the FWPCA); Waste Water Disposal Permit (the Department may adopt the NPDES permit issued by USEPA as the required State permit) 2. Department of Fish and Game, Habitat Protection Service - Anadromous Fish Protection Permit. Required of any any hydraulic project located ona catalogued anadromous fish stream, this permit may impose stipulations on construction timing, project design and operation requirements, and other mitigation measures. 36 Department of Natural Resources, Division of Land and Water Management - Water Use Permit (authorizes dam construction and appropriation of water). 4. Office of the Governor, Division of Policy Development and Planning, Office of Coastal Management - review of development profjects 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). The State permits and review listed above are all included in this process which is not mandatory but rather intended to aid the applicant. 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 & USOCZ2M 1979). Although no explicit or G-C-6 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 will be subject to the federal, State, and local environmental review and regulatory process outlined previously. In order to facilitate future project planning and development it is recommended: ts 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 potential impacts outlined previously should also be discussed with these agencies. 2. 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. 36 That other agencies with major review and or regulatory 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. 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-Thayer Creek - 112-117-050. 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 30, 1979. 578 p. + maps. Brannon, Ed. 1979. Group Leader for Land Management Planning and Regional Environmental Coordinator, U.S. Forest Service, Juneau, Alaska. Personal communication. Clark, Roger N. and Robert C. Lucas, 1978. The Forest Ecosystem of Southeast Alaska: 10. Outdoor Recreation and Scenic Resources. USDA Forest Service Gen. Tech. Report PNW-66. Pacific Northwest Forest and Range Experiment Station, Portland, Oregon. 116 p. 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 Adminstation, Juneau. Ingledue, Don, 1979. Alaska Dept. of Fish and Game, Division of Commercial Fisheries, Juneau. Personal communication. Reed, Richard, 1979. Alaska Dept. of Fish and Game, Habitat Protection Service, Regional Supervisor, Juneau. Personal communication. 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 44FR 29478, May, 1979. G-C-8 U.S. Army Corps of Engineers (USACE). 1976. Final Environmental Impact Statement for Proposed Small Boat Harbor, Hoonah, Alaska. Alaska District, USACE, Anchorage, January 1976. 54 p. + 3app. 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. G-C-9 Exhibit G-C-l ACRONYMS ADEC Alaska Dept. of Environmental Conservation ADFG Alaska Dept. of Fish and Game ADNR Alaska Dept. of Natural Resources DPDP Division of Policy Development and Planning FERC Federal Energy Regulatory Commission FWPCA Federal Water Pollution Control Act LUD Land Use Designation NPDES National Pollutant Discharge Elimination System REA Rural Electrification Administration USACE U.S. Army Corps of Engineers USEPA U.S. Environmental Protection Agency USFS U.S. Forest Service USFWS U.S. Fish and Wildlife Service VCU Value Comparison Unit SCIENTIFIC NAMES Common Name hemlock, mountain hemlock, western spruce, Sitka bear, brown deer, Sitka black-tailed salmon, chum (dog) salmon, coho (silver) salmon, pink (humpback) duck, harlequin curlew, Eskimo falcon, American peregrine falcon, Arctic peregrine goose, Aleutian Canada Trees Mammals Fish Birds Exhibit G-C-2 Scientific Name Tsuga mertensiana Tsuga heterophylla Picea sitchensis Ursus arctos Odocoileus hemionus sit- kensis Oncorhynchus keta Oncorhynchus kisutch Oncorhynchus gorbuscha Histrionicus histrionicus Numenius borealis Falco peregrinus anatum Falco peregrinus tundrius Branta canadensis leuco- pareia Appendix G-D REFERENCES Federal Power Commission and the Forest Service - U.S.D.A. "Water Powers 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 Requirements Study", May 1979 draft.