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HomeMy WebLinkAboutScammon Bay Small Hydropower Study and Environmental Assessment 1982seA 002 Scammon Bay, Alaska I Small Hydropower Interim Feasibility Study arid Environmental Assessment US Army Corps of Engineers Alaska District -..--~ MARCH 1982 .- SUMMARY Scammon Bay, an isolated Eskimo village in the Yukon-Kuskokwim Delta region of southwestern Alaska, has been subjected to large increases in electrical generation costs. Diesel fired electrical generation costs have more than doubled, from 21.9 cents/kWh in 1975 to 48.3 cents/kWh in lQ81. With the prospect of ever increasing fuel costs, village electrical generation costs will continue to increase. This study considered various alternatives that could either supple- ment or replace diesel generation. Two alternatives were identified that could have a significant impact on electrical generation, wind generation and hydropower, neither of which could totally eliminate the use of diesel. Hydropower generation, the selected plan, would displace an estimated 229,000 kilowatt-hours (kWh) during 1984, the first year of operation. This is estimated to increase to 278,000 and 314,000 by 1990 and 1995, respectively. The hydropower system would consist of a small dam, 3500-foot penstock, and a powerhouse with a 100-kilowatt (kW) turbine- generator unit. The estimated first cost in October 19B2 dollars is $1,483,000, with operation and maintenance estimated at $22,000 annually. This system could produce an estimated 409,000 kWh from April through October. Approximately 56 percent is estimated to be usable during 1984, the first year of operation. Wind generation appears to have good potential during the winter months when high winds of long duration occur; however, wind potential during the summer months appears relatively poor. The exact extent of Scammon Bay's wind resource has never been assessed, making detailed evaluation difficult. Even if this infonnation were available, the state- of-the-art in wind generation is such that no units are currently commercially available that could meet the village's need for oO-cycle alternating current unless they utilized induction generators. These could only meet a very small portion of the energy needs at anyone time (approximately 15-25 percent). If a commercially viable wind system becomes available that could function as an integral part of the Scal1l11on Bay systeM, it appears that it could complement the hydropower system. Wind potential is greatest during the winter \'Ihen the hydrosystem would be shut down and least in the summer when hydropower potential is greatest. i R: 8/A2 SCAMMON BAY PERTINENT DATA SHEET SCAMMON BAY GENERAL DATA Project Installed Capacity Number of Units Type of Turbine Average Annual Energy Estimated Usable Energy (1984) Estimated Usable Energy (1990) Dependable Capacity Penstock length Penstock diameter Gross Head Design Head ECONOMIC DATA Project First Cost Project Annual Cost Project Annual Benefit Net Annual Benefit Benefit-Cost Ratio iii 100 kW 1 Impulse 409,000 kWh 229,000 kWh 278,000 kWh o 3,500 ft. 12 in. 488 ft. 430 ft. $1,483,000 $145,000 $170,000 $25,000 1.2 to 1 R: 8/82 TABLE OF CONTENTS II·JTRODUCTIOt~ •••••••••••••••••••••••••••••••••••••••••••••••••••••• 1 1.1 AUTHORITY •••••••..•••••••••••••••••••.•.••••••.••••••••• 1 1.2 SCOPE OF THE STUDY •.•..•.........•..•.•.•...••.•••••••.• 1 1.3 STUDY PARTICIPANTS ....•..•.•••.••.••.••••••....•..••••.. 2 1.4 STUDIES BY OTHERS •....••.•.....••••.••.•...••••...••••.• 2 EXISTHJG CONDITIONS ............................................... 3 2.1 COMMUNITY PROFILE .....•....•.••••••••.••..••.••.•..••.•• 3 2.2 NATURAL SETTING ••••••••• It ••••••••••••••••••••••••••••••• 7 2.3 ELECTRICITY USE .....••....•.......••••..••••.....•••... 10 PROBLEMS, ~EEDS, AND STUDY OBJECTIVES •....•...•..•....•...••••••• 15 3.1 POWER SLlPPL Y AND FUTURE DEHAND ......................... 15 FORMULATION AND EVALUATION OF ALTERNATIVES •..•••...••••••.•••.... 20 4.1 ALTERNATIVES ..•.••......•••••..••.••..••..••••...•.•.•• 20 4.2 SUHMARY OF BEST ALTERI~ATIVES (SOA) •.••.•••...•..•••.••. 28 4.3 NED PLAN •..•......•....•.....••...••......••.••••.••••. 32 4.4 EQ PLAN .•..•••...•.••••..••••.•.••.•.•...•.••.••.•••••. 32 4.5 SELECTED PLAN .•...•....••.••..•...•.•.•..•.•...•••.•••• 32 CONCLUSIONS AND RECOMMENDATIONS .•....•.••...••••...••....•.•....• 33 5.1 cotJCLUSIONS •••••••••••••••••••••••••••••••••••••••••••• 33 5.2 RECOMMENDAT I ON •••••••.••••••••••••••••••••••••.•.•• -•••• 33 TECHNICAL ANALySIS •••••.•.•.••..•.•••.••..••..••••••.••.•••••..•• 35 T.l GENERAL •..••....••.•.......••••...••.••.•.••....•..•••• 35 T.2 HyDROLOGy ••.....••..••....••.••.•••••••....•••••.•••••• 35 T.3 GEOLOGY .•.••••••.•••.•••.•••..•••••••••••.••••••••••••• 51 T.4 DAM AND SPILLWAY, AND INTAKE .•.•••••..•..•..•...••.•.•• 51 T.5 PENSTOCK .•.•••••••..••..•••..••••••••••••••.•.•••••...• 54 T.6 POWERHOUSE .•.••..••.•.••..•••••••..•.••..•••.•.....••.. 54 T.7 TRANSMISSION SYSTEM ••.••••...••••••••.•.••••••••••••••• 56 T.8 ALTERNATIVE DESIGNS CONSIDERED ..•...•••......•..•••.•.• 57 T.9 CONSTRUCTION PROCEDURES ....•........•...•....••....•••• 58 T.l0 PROJECT OPERATION AND MAINTENANCE ••.....•••.•...•.••••. 5R T.ll PROJECT COST ••••....•.•.•••••••••••.••..•....••..•.•..• 61 T.12 PROJECT ECONOMICS ••.••.•..•••.•••..•••••.••....•••..••• 62 PLATES FINDING OF NO SIillJIFICANT IMPACT .•••.•••••.•••.•.•••••• yel1ow pages ENVIRONMENTAL ASSESSMENT ......••...•..•.••.••.••..••..• yellow pages FISH AND WILDLIFE COORDINATION ACT REPORT •••••••••••••.•• Appendix A PUBLIC VIEWS AND RESPONSES ..•.•..•.•.••...••••.•.••••...• Appendix B iv I NTRODUCT ION 1. 1 AUTHOR lTV The evaluation of small scale hydroelectric systems was authorized by a United States Senate Resolution dated 1 October 1976. That resolution directed the U.S. Army Corps of Engineers to determine the feasibility of installing small prepackaged hydroelectric units in isolated communities throughout Alaska. The full text of the resolution reads as follows: RESOLVED BY THE COMMITTEE ON PUBLIC WORKS OF THE UNITED STATES SENATE, that the Board of Engineers for Rivers and Harbors be, and is hereby requested to review the reports of the Chief of Engineers on Rivers and Harbors in Alaska, published as House Document Numbered 414, 83rd Congress, 2nd Session; Southeastern Alaska, published as House Document Numbered 501, 83rd Congress, 2nd Session; Cook Inlet and Tributaries, Alaska, published as House Document Numbered 34, 85th Congress, 1st Session; Copper River and Gulf Coast, Alaska, published as House Document Numbered 182, 83rd Congress, 1st Session; Tanana River Basin, Alaska, published as House Document Numbered 137, 84th Congress, 1st Session; Southwestern Alaska, published as House Document Numbered 390, 84th Congress, 2nd Session; Northwestern Alaska, published as House Document Numbered 99, 86th Congress, 1st Session; Yukon and Kuskokwim River Basins, Alaska, published as House Document Numbered 218, 88th Congress, 2nd Session; and other pertinent reports, with a view to determining the advisability of modifying the existing plans with particular reference to the feasibility of installing 5 MW or less prepackaged hydroelectric plants to service isolated communities. 1.2 SCOPE OF THE STUDY This interim study was undertaken to determine if economically and environmentally feasible alternatives exist that could meet or supplement the future electrical energy needs of Scammon Bay. Potentially feasible alternatives were evaluated in sufficient detail to allow expedited implementation. This study considered only electrical energy needs since total energy needs were evaluated in the Alaska Power Authority's (APA) energy study, recently completed by Northern Technical Services (NORTEC). A summary of findings for the Scammon Bay portion of the APA study is given under Section 1.4 STUDIES BY OTHERS. 1.3 STUDY PARTICIPANTS A multidisciplinary team composed of the following agencies assisted the Alaska District, Corps of Engineers in preparation of this report. -U.S. Fish and Wildlife Service -U.S. Public Health Service -U.S. Bureau of Indian Affairs -Alaska Power Administration (Federal) -Alaska Power Authority (State) -Alaska Village Electrical Cooperative -Northern Technical Services (NORTEC) The cooperation of the people of Scammon Bay is also gratefully acknowledged. 1.4 STUDIES BY OTHERS The United States Department of Energy, Alaska Power Administration, prepared the "Small Hydroelectric Inventory Of Villages Served By Alaska Village Electrical Cooperative" in December 1979. This study assessed the potential for hydroelectric development at over 40 villages in western Alaska. Scammon Bay was found to be the most likely village of those studied to have a feasible hydropower site. This preliminary investigation considered two potential development schemes, one with an installed capacity of 170 kW, the other with 285 kW. These preliminary estimates were based on an estimated average streamflow at the damsite of 9 cubic feet per second (cfs). Subsequent investigations and streamflow measurements by the Corps of Engineers indicated an average annual streamflOltJ of about 2.5 cfs, well below that assumed. NORTEC prepared a report for the Alaska Power Authority entitled Reconnaissance Study of Energy Requirements and Alternatives, Togiak, Goodnews Bay, Scammon Bay, and Grayling, February 1981. The NORTEC study addressed all energy needs on a reconnaissance level, including electrical, heating, cooking, and transportation. It projected future energy needs for electrical and heating purposes and evaluated numerous alternatives to meet these needs. Alternatives determined worthy of further consideration included energy conservation, direct waste heat capture, hydropower, and possibly wind generation. The first two alternatives, energy conservation and waste heat recovery, related primarily to the heating load. Hydropower and wind would provide electrical energy, with diesel providing backup in both cases. Other alternatives considered, but determined infeasible, included Rankine Cycle waste heat capture, fuel cells, geothermal, tidal. solar photovoltaic, steam, and gasification. 2 -NORTEC's projected energy demand for Scammon Bay took into account the recent addition of a 6,500-square-foot high school and the planned 1981-1982 addition of 24 housing units by U.S. Department of Housing and Urban Development (HUD). Above that, a conservative growth in energy demand of 0.9 percent was used beginning in 1982. The 0.9 percent estimated growth rate is well below the historical growth rate for Scammon Bay, but past increases were largely due to the initial acquisition of electrical appliances during electrification. NORTEC assumed that increasing costs, coupled with conservation would temper future growth; however, with the passage of the "Power Cost Assistance Program" by the Alaska Legislature in August 1981, power costs will be subsidized (in Scammon Bay) to a level below the 1975 consumer cost. In addition to this change, comments by HUD on the draft report indicate that 39, instead of 24, housing units will be constructed along with a new 7,200-square-foot recreation center. As a result, NORTEC's forecast must be considered low. EXISTING CONDITIONS 2.1 COMMUNITY PROFILE Scammon Bay is an Eskimo village located in the Yukon-Kuskokwim Delta region of southwestern Alaska. The village, originally named Mariak, was officially renamed Scammon Bay in honor of Captain Charles M. Scammon who served as marine chief of the Western Union Telegraph Expedition in Alaska from 1856 to 1867. 2.1.1 Population Data from the 1980 census indicate a population of 250 at Scammon Bay. This represents an average population increase of over 4 percent per year since the 1970 census. However, the actual yearly growth rate has varied considerably as can be seen below: Year 1940 1950 1960 1970 1975 1976 1977 1978 1979 1980 Table 2.1 HISTORIC POPULATION OF SCAMMON BAY 3 Population 88 103 115 166 165 192 225 193 232 250 2.1.2 Government and Services Scammon Bay was incorporated as a second class city in 1967. The seven-member city council selects the town mayor and administrator. In addition~ the city employs a clerk, secretary/treasurer, police, and maintenance personnel. Other employment sources include the Bureau of Indian Affairs School, the Rural Parent-Child Program, and seasonal fire fighting for the Bureau of Land Management. Scammon Bay's native population is represented by a five-member traditional council, which is the official tribal governing body for the village. The council is eligible to administer a variety of Federal programs, including local health care, employment assistance, college assistance, social services, etc. 2.1.3 Transportation and Communication Scammon Bay is accessible by air, water, and winter trail. Fuel and bulk supplies are barged to the community from June to September. The Kun River serves approximately 60 privately owned boats, providing transportation to fish and berry camps. A 2,800-foot gravel airstrip north of the city enables daily sched- uled commercial air service. Principal air carriers include Sea Airmo- tive and Wein. Scammon Bay has approximately 1 mile of gravel road for use by the few vehicles in town. Snowmachines, owned by nearly every household in the community, are the major form of transportation in winter. The community members have access to one telephone located in the community hall. Television is also available from the Alaska Statewide Satellite Communications network. 2.1.4 Economy Year-round employment in the city is available through local govern- ment and trade. In the trade sector, employers include the airport, four small stores, and the general store. Some residents also sell handmade grass baskets, ivory carved jewelry, and other handicrafts. In addition to the government, commercial fishing is the other primary source of income for Scammon Bay. As of 1979, the Yukon District had issued 40 gill net permits to Scammon Bay residents. Commercial species include salmon and to a lesser extent herring. Herring are anticipated to become a larger portion of the cash economy with the investment by the Alaska Renewable Resource Corporation in the construction of approximately 10 herring fishing boats at Scammon Bay. In addition to these commercial catches, noncash landings include whitefish, blackfish, needlefish, smelt, and tomcod. 4 Income from the aforementioned activities is supplefftented by subsis- tence hunting and gathering, and to some extent, assistance payments. In addition to fish. residents of the area hunt walrus. seal. geese, swans, cranes. ducks. loons, and ptarmigan. In the fall, various types of berries such as blueberries. cranberries, and salmonberries are har- vested. Table 2.2 indicates the overall employment distribution for Scammon Bay. Table 2.2 SCAMMON BAY 1979 EMPLOyt-'IENT BY I~STRY Part-Time Gill Netting 40 1/ BLM * City Airport BIA School Reta i 1 Parent-Child Program Handicrafts * TOTAL 40 Year-Round 11 1 92/ 8 2 31 Source: Alaska Department of Community and Regional Affairs 1/ Based on number of gill net permits only. Actual participation is greater. 1/ The new high school has added additional employment beginning in 1980. *Number Unknown 5 SCAMMON BAY HIGH SCHOOL ------ SCAMMON BAY FISHING FLEET :'~ 2.2 NATURAL SETTING 2.2.1 Climate The area has a maritime influence as indicated by its relatively moderate temperatures and precipitation. The Askinuk Mountains influence the climate at Scammon Bay, such that the various pressure systems approaching from the ocean or the Yukon-Kuskokwim Delta have a direct effect on the village. The nearest climatological station is located at Cape Romanzof Air Force Station approximately 15 air miles away. Although Cape Romanzof is at approximately the 435-foot elevation and has a southwest exposure, it represents the only nearby site for approximation of weather at Scammon Bay. Cape Romanzof data, obtained from National Oceanic and Atmospheric Administration (NOAA) records for the period 1953-1978, indicate that average temperature ranges during summer and winter are 34° F to 49° F and 9° F to 31° F, respectively, with recorded extremes of -26° F and 79° F. The average monthly precipitation ranges between 0.98 and 5.00 inches with an annual average of 25.45 inches. The maximum monthly precipita- tion for the period of record is 10.50 inches with the maximum 24-hour precipitation being 2.77 inches. Table 2.3 and 2.4 provide a monthly breakdown of precipitation, temperature, snow, and wind. 2.2.2 Regional Geology Scammon Bay is situated on the northern foot of the Askinuk Mountains in a region almost entirely composed of the flat, low-lying deltas of the Yukon and Kuskokwim Rivers, with an occasional rock hill rising several hundred to a couple of thousand feet above the delta plain. Ground moraines in the cirques and valleys indicate extensive glaciation, proba- bly of Wisconsin Age. Permafrost occurs sporadically throughout the region, but may not be evident in rock formations where the moisture content is low. 7 TABLE 2.3 CAPE ROMANZOF CLIMATOLOGICAL DATA 1/ PREC I P ITATION: 2/ JAN FER MAR APR ~1AY JUN JUL AUG SEP OCT NOV DEC ANNUAL AVERAGE 1.11 0.98 1.25 .97 1.28 2. 13 2.95 5.00 4.62 2.39 1.56 1. 21 25.45 MAX MONTH 4. 17 4.25 6.83 3.44 3.72 4.31 6.45 8.78 10.50 6.09 5.46 4. 14 10.50 MAX 24 HOUR 0.99 1. 15 1.20 0.90 0.74 1.88 1.95 2.77 2.09 1.34 1.97 1.30 2.77 TEMPERATURE: AVERAGE 12.9 9.7 13.5 20.7 34.4 43.3 49.2 49.2 43.7 31. 1 22.6 12.8 28.6 MAXIMUM 49 48 46 60 63 72 79 73 63 60 43 48 79 MINIMUM -23 -26 -26 -12 3 25 31 33 23 4 -7 -23 -26 SNOW PACK: 'i/ OJ AVERAGE 7.8 11.8 15.3 18.6 12.9 1.4 0.0 0.0 0.0 O. 1 2.9 5.9 STANDARD DEV IATION 6.8 9.7 14. 1 20.6 8.3 3.3 0.0 0.0 0.0 0.64 3.2 5.7 STATION INFORMATION: LATITUDE -61 0 46' LONGITUDE -166 0 03' ELEVATION -434' 1/ From Climatological Data 1953 through 1978 2/ "Rainfall in inches 3/ Snow pack (including snow and sleet) on the ground, in inches, on the first of each month. () () () () TABLE 2.4 CAPE ROMANZOF WIND DATA (Knots) SUBJECT JAN FEB MAR APR t~AY JUN JUL AUG SEP OCT NOV DEC ANNUAL Prevailing Wind, Mean Velocity lq.2 20.2 17.0 16.9 13.8 11.8 9.fi 11.8 11.8 14.3 16.8 17.8 15.6 Direction NE NE NE NE NE NE SSW SSW NE NE NE NE NE % Time 16.9 21.4 17. 1 15.2 18.0 12.6 14.7 13 .0 lfi.6 19.7 18.6 21.3 16.2 2.2.3 Biology The most important wildlife resources of the Yukon-Kuskokwim Delta in the vicinity of Scammon Bay are the various species of birds that use the coastal lowlands. Some of the highest density goose breeding areas in the world are found on the outer fringes of the Yukon-Kuskokwim Delta. The majority of the Yukon-Kuskokwim Delta is classified as wet tundra, which. primarily supports low stands of sedge and cottongrass with a few woody plants. With the lack of cover and absence of year-round food sources, the western Yukon-Kuskokwim Delta does not support large terrestrial mammals. Only on rare occassions have big game animals been observed near the project vicinity. Five species of Pacific salmon are indigenous to the Scammon Bay vicinity, although no salmon enter the freshwater streams near the project area. The bulk of the salmon found in the marine waters off Scammon Bay are headed for the Yukon River drainage. 2.2.4 Anthropology and Archeology According to the State Historic Preservation Office, no known sites are eligible for inclusion in the National Register of Historic Places in the Scammon Bay area. 2.3 ELECTRICITY USE 2.3.1 Historic Use Prior to joining the Alaska Village Electrical Cooperative (AVEC) in 1974, Scammon Bay's limited electrical needs were met with a few individual generators and a small windmill that supplied power for two homes. Since AVEC electrification, ~nergy demand has grown substantially. Table 2.5 shows peak demand in kW and annual energy generation for the years 1975 to 1980. Accurate records were not kept during the early years, resulting in missing data. * Unknown Table 2.5 SCAMMON BAY: (AVEC ANNUAL PEAK AND ENERGY GENERATION) Year 1975 1976 1977 1978 1979 1980 Peak kW * * * 54 78 78 10 Ener9.l MWh 159.2 185.0 203.5 214.5 269.3 310.0 2.3.2 Non-AVEC Generation In addition to AVEC generation, the local BIA elementary school and the newly constructed high school maintain three standby generators totaling 160 kW. Under normal conditions, both schools would purchase power from AVEC. However, with the additional load of the new high school, which opened in September 1980, the standby generators were used almost daily to meet the increased demand. Recent upgrading of the existing AVEC generators from 50 and 75 kW to 75 and 110 kW has rectified this situation. 2.3.3 Users In addition to the BIA school (three classrooms) and new high school (6,500 sq. ft.), the community has a variety of public and residential structures which comprise the electricity demand of Scammon Bay. Public buildings include the community center, the traditional council building, armory, clinic, post office, Luther Aguchak Memorial Building, and two churches. Four stores, several warehouses, a movie theater, and the AVEC building are also located in the city. Approximately 45 single family dwellings are in Scammon Bay, mostly of wood-frame construction. Of these, 15 were built in 1970 by the Alaska State Housing Authority. In all, about 60 structures are served by AVEC. Of the 269,300 kWh gener- ated by AVEC in 1979, 107,500 kWh were for residential consumption and 94,800 kWh went to government and school use, with the remaining used by the utility or lost due to distribution system inefficiency. End use data from 1975-1979 for Scammon Bay is shown below: Table 2.6 END USE ELECTRICAL ENERGY 1975-1979 AVERAGE Vi 11 age Residential Commerical Scammon Bay 35% 5% *Includes schools and other public facilities. -Northern Technical Services 1980 2.3.4 Total Energy Use Other* 60% Scammon Bay is currently dependent upon fuel oil for space and water heating and electrical generation. Propane is used in the village primarily for cooking. Gasoline is used for snowmobiles and fishing boats. There is limited use of driftwood and the local willow brush for horne heating. Table 2.7 describes the end use of all energy forms utilized in Scammon Bay during 1979. The amount of fuel oil used for home heating, divided by the number of households, indicates a per household consumption of 680 gallons annually. This figure is low relative to comparable villages. 11 END USE ENERGY FORM Conversion to Elec- tricity Residential and small commerical space and water heating (nontransportation) Municipal and other public (nontransportation) Military (nontransportation) Transportation BIA School (nontransportation) NOTES: Table 2.7 ENERGY INPUT AND END USE FOR SC~~MON BAY Numbers in parentheses () are (10 6 Btu) 01 ESE L/ #1 01 L Gallons 31,0001 (4185.0) 34,700 (4684.5) 6,000 (810.0) 2,300 (310.5) 200 (27.0) 29,000 (3915.0) GASOLINE/ AVGAS Ga 11 ons 28,000 (3500.0) PROPANE Pounds 10,000 3 (216.7} ELECTR I C ITV Kilowatt Hours 67,100 2 (229.0) 107,500 4 (366.7} 15,400 4 (52.6) 900 4 (3. 1 ) 78,500 4 (267.9) Gross generation from 31,000 gallons fuel oil was 269,300 kWh for a conversion efficiency of 22.0 percent. 2 Power consumed by the utility for station service (lights, fuel pumping, etc.) and system distribution losses. 3 Propane is used solely for cooking. 4 Net utility electrical sales in 1979 were 269,300 kWh. Source: Northern Technical Services o 0 - .- 2.3.5 Rate Structures Before the Power Production Cost Assistance Program (PPCA Program) went into effect in November 1980, electric bills were claiming an increasing proportion of the village's cash economy. That proportion stood at approximately 10 percent of annual cash income in 1979. The Power Production Cost Assistance Program dropped the effective kWh cost of electricity from 40.8¢ to 26.6¢ for late 1980 and early 1981. On 4 August 1981, the Power Production Cost Assistance Program was repealed by the Alaska Legislature and replaced with the Power Cost Assistance Program (PCA Program). This new program, effective January 1982, will subsidize 95 percent of electrical energy costs (except return on equity) greater than 12¢ and less than 45¢/kWh during its initial year. This will drop the consumer cost of electricity at Scammon Bay to approximately 21.3¢/kWh from the actual utility cost of 48.3¢/kWh. The utility rates since AVEC power was introduced in Scammon Bay are presented in Table 2.8. The single rate schedule shown is applied to all 48 AVEC villages and is designed to recoup the costs of the entire system. Costs attributable to any single village are difficult to ascertain. Year 1975 1976 1977 1978 1979 1980 1981 2.3.6 Fuel Costs Table 2.8 AVEC RESIDENTIAL RATE 1975-1981 (75 kWh) Rate (¢ per kWh) 21. 9 22.8 29.0 34.2 36.7 40.8 48.3 Consumer Cost (¢ per kWh) 21. 9 22.9 29.0 34.2 36.7 26.6 (PPCA Program) 21.3 (PCA Program after 1 Jan 82) For electrical generation, fuel prices have been the principal source of rising costs. The average cost of diesel fuel delivered to AVEC villages since 1973 is shown below: Table 2.9 AVERAGE COST OF DELIVERED FUEL TO AVEC VILLAGES 1973-81 Year 1973 1974 13 Cost ($/ga 1 ) 0.35 0.52 Table 2.9 Con't AVERAGE COST OF DELIVERED FUEL TO AVEC VILLAGES 1973-81 Year 1975 1976 1977 1978 1979 1980 1981 1982 (est.) Cost ($/gal) 0.58 0.65 0.72 0.78 0.97 1.33 1.62 1.68 Based on data provided by NORTEC, AVEC's ScaJll110n Bay generators produced an average of 8.7 kWh/gal from January 1979 to September 1980. In 1981, this output reached 9.2 kWh/gallon. As of March 1982, the fuel efficiency of the existing generators is 7 kWh/gallon because they were altered to increase peak capacity. This fuel efficiency is expected to prevail until 1994, when the useful life of the generators expires and they are replaced. In 1995, fuel efficiency is expected to be 9 kWh/gallon. R: 8/82 14 -PROBLEMS, NEEDS, AND STUDY OBJECTIVES Based upon Scammon Bay's initial study request and subsequent informa- tion gathered during four site visits, it became apparent that a plan needed to be formulated that would reduce the cost of power to the local residents. With the establishment of the Power Cost Assistance Program by the State of Alaska, the basic ohjective of reducing cost to the consumer was met, at least for the short term. However, this program is only a subsidy, doing nothing to reduce the real cost of power production. Therefore, the study objectives were reestablished as follows: 1. Reduce the real cost of energy generation. 2. Maintain the existing environment. In addition to the above study objectives, the national objectives of National Economic Development (NED) and Environmental Quality (EQ) must be considered. NED is obtained by increasing the level of output or economic efficiency of the nation and the EQ objective is obtained by preserving, maintaining, or enhancing the cultural and natural resources of the study area. 3. 1 POWER SUPPLY AND FUTURE DEMAND This section provides a summary of the generating capabilities of Scru~on Bay and an estimation of the future energy needs that must be met by any alternative. 3.1.1 Generating Facil ities The generating capabilities of Alaska Village Electrical Cooperative's Scammon Bay generators are shown below. Besides those shown, a 105-kW generator is scheduled for installation during early 1982. -75 kW, 1,800 rpm, KATO (1971), 120/240, 10, -110 kW, 1,800 rpm, KATO (1971), 120/240, 10, 75 kW 110 kW 185 kW In addition to AVEC's generators, the standby generating capacity of the new high school and BIA school totals 160 kW. The high school generator is new while the BIA units are between 10 and 15 years old. These are shown below: High School 1 -100 kW, Newage -Stamford, 120/240, BIA School 1 -35 kW, Kohler 120/240, 1 -25 kW, Kohler 120/240, 1 5 10, 100 kW 10, 35 kW 10, 25 kW 160 kW 3.1.2 Generation and Transmission Efficiency In 1979, AVECls gross generation from 31,000 gallons of fuel oil was 269,300 kWh for a conversion efficiency of 22.3 percent. Station service and distribution losses amounted to 67,100 kWh or approximately 25 per- cent of the gross power generated. AVECls records indicate a total system distribution loss of 47,600 kWh or 18 percent. This is considered typical of a single phase distribution system. 3.1.3 Future Activity And Energy Needs It is difficult to accurately predict the future electricity ~emand in rural villages because it is difficult to predict the economic growth of an individual community. Economic growth depends on the development opportunities exercised under the Alaska Native Claims Settlement Act, the general economic development of the State and region, and the availability of electricity to the community. In addition, each village is a small isolated unit. A change in the habits of a few households or the local school can have a dramatic effect on the total level or composition of electricity demand in a community. More importantly, the level of demand in any bush village largely depends on government decisions made outside the control of the community. The electric needs of AVEC villages are mainly determined by the demand generated by the following installations: a. State Schools b . B I A Sc hoo 1 s c. Public Health Services d. Housing Authorities e. Federal Aviation Administration f. Satellite Communications Recent construction activities in Scammon Bay include the previously mentioned high school and a water supply distribution system installed by the Public Health Service in the mid 1970 1s. Construction of 39 n.ew single family homes is scheduled for completion by June of 1982. These new housing structures are expected to vary from 860 to 1,100 square feet. A combination recreation center and gymnasium is also scheduled for construction in 1982 or 1983. This facility would be approximately 7,200 square feet. 3.1.4 Long Term Outlook Looking beyond the 1980 1s, Scammon Bay presents potential for various growth possibilities. Probably the largest single contributing factor to the future outlook of Scammon Bay and other isolated Alaskan Villages is Alaska1s oil wealth. How the State ultimately spends its oil revenues will greatly influence the future growth of remote villages. Any expansion in the Scammon Bay economy besides government positions will probably be in the fishing industry. This influence has already 16 - been felt by the previously mentioned investment in herring fishing boats by the Alaska Renewable Resources Corporation. However, expansion in the foreseeable future will most likely continue on a relatively small scale. 3.1.5 Load Forecasts Any forecasts of future energy demand for Scammon Bay are speculative. Beyond the existing demand and the future demand of the new housing units and recreation center, energy forecasts are extremely uncertain. Once new construction is complete, the demand may stabilize, at least until additional unforeseen capital improvements take place. However, with the passage of the PCA Program, which will drop rates to pre 1975 levels, the likelihood of the demand stabilizing substantially appears to be remote. The most recent energy demand forecast was developed by NORTEC for the Alaska Power Authority prior to the PCA Program. Their forecast included the effects of the new high school in 1980 and the 1981-1982 addition of 24 homes. Above that, a conservative growth rate of approximately 0.9 percent was used. This is substantially less than the actual increase over the past five years, but they assumed that the relatively rapid electrification of individual homes that has taken place since joining AVEC would stabilize. Future increases due to added appliances were assumed to be offset by conservation and more efficient appliances. This energy forecast (Figure 3.1) is now considered to be the low growth scenario due to the decreased cost to the consumer provided through the PCA program. Also shown on Figure 3.1 are growth projections of 14.3 percent, 11 percent and 4.5 percent. The 14.3 percent figure represents an extrapo- lation of the electrical growth rate between 1975 and 1980 at Scammon Bay. The 11 percent figure corresponds to the 1970 to 1980 growth rate at Bethel, Alaska. Neither of these are considered to be indicative of future growth at Scammon Bay. The first figure represents a very short period of record during the time of initial electrification at Scammon Bay, the latter, which has a longer period of record, represents a larger community with a broader economic base. The R.W. Retherford Division of International Engineering Company, Inc., completed a study of energy requirements and alternatives for 13 villages in west and northwest Alaska. Based on their energy demand analyses, an electrical growth rate of 4.5 percent was found to be the most reasonable for these villages, many of which are similar in size and economy to Scammon Bay. Because of their similarity to Scammon Bay and the previously mentioned effect of the PCA Program, the 4.5 percent growth forecast has been adopted for this study. Figure 3.2 shows the estimated monthly distribution of energy gener- ation for 1984 and 1990. The percentages were based on 1979 usage patterns. The combination of information presented in these two figures was used to provide the basis for evaluating alternative energy plans. 17 en 0::: ~ o ::z:: () PROJECTED GENERATION PROJECTION BASED ON HISTORICAL.....;......-w INCREASES (14.3%) PROJECTION BASED ON BETHEL HISTORICAL INCREASES (11%) R. W. RETHERFORD ASSOC. PROJECTION ADOPTED FOR THIS STUDY (4.5%) . NQRTEC PROJECTION PRIOR TO PCA PROGRAM (0.9%) ADJUSTED FOR ADDITIONAL HOUSING AND RECREATION FACILITY ,,~:::=:=~~~- PLANNED REC CENTER/GYM -73 MWH FOR PLANNED HUD HOUSING FIGURE 3.1 66 MWH FOR NEW HIGH SCHOOL SCAMMO~ BAY, ALASKA HISTORICAL 8 PROJECTED ENERGY GENERATION ALASKA DISTRICT, CORPS OF ENGINEERS FEBRUARY 1982 n 78 79 10 • 82 83 84 85 86 .., • 81 90 9t 92 9394 ge YEARS o - C/) 40 a::: ::::> o :I: O~"~~~~"~~~+-~+-~~~~--~~~~~~~ JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC esaJ 1990 o 1984 MONTH FIGURE 3.2 SCAMMON BAY) ALASKA ESTIMATED MONTHLY ENERGY DEMAND ALASKA DISTRICT" CORPS OF ENGINEERS FEBRUARY 1982 19 FORMULATION AND EVALUATION OF ALTERNATIVES 4.1 ALTERNATIVES Under section 1.4, STUDIES OF OTHERS, the work done for the Alaska Power Authority by NORTEC was summarized. NORTEC's conclusion was that energy conservation (insulation and weatherization), continued use of oil, waste heat recovery, hydropower, and poss"ibly wind generation were the best alternatives for Scammon Bay. These were the only five alternatives that met both requirements of being technically feasible and constructibl e in the study area. Other al ternati ves such as geothennal or tidal power are not technically feasible at Scammon Bay due to natural constrai nts. 4.1.1 Diesel This alternative is effectively the existing condition. Under this scenario, diesel generation would continue to be used to meet all electrical requirements at Scammon Bay. With the addition of the new 105-kW generator, AVEC should have sufficient capacity to meet village demands until the early 1990's. Impact Assessment The primary impact associated with this alternative is economic. Although the PCA program will lower diesel prices to their 1975 price levels, the cost of diesel fuel will eventually rise again as shortages occur and demand exceeds supply. By continuing to use diesel, the village is leaving itself exposed to possible shortages in the future if supplies are interrupted due to physical or economic constraints. Evaluation Since diesel has been established as the base case by which other alternatives are to be evaluated, it is necessary to estimate the actual generation cost at Scammon Bay for comparison. The Alaska Village Electrical Cooperative 1981 cost is 48.3¢/kWh. This system wide cost includes not only fuel and operation and maintenance, but also taxes, insurance, interest, depreciation, and administration. Of this kWh cost, not all can be considered as a savings or a benefit if an alternative is implemented. Only fuel and operation and maintenance costs (O&M) can be claimed as benefits, unless an alternative can be implemented that is reliable enough to prevent the need for acquiring additional diesel generators to meet peak loads; then it can be credited for the firm capacity it provides. This is called the capacity benefit. The two parts of the energy benefit, fuel and operation and maintenance, were detennined from infonnation provided by AVEC. AVEC's 1982 diesel cost of $1.68/gallon, coupled with Scammon Bay's generating efficiency, which is 7 kWh/gallon, provides a fuel cost of 24.Q¢/kWh. R: 8/82 20 This, coupled with AVEC's operation and maintenance cost of 6.85¢/kWh, renders a cost of diesel generation of 30.85¢/kWh for 1982. When comparing this cost to another alternative, consideration must be given to how the fuel cost portion may change in the future. With total fuel price increases at Scammon Bay of 212 percent, from 1974 to 1981, it is easy to see that energy costs have far outstripped inflationary increases over the same time period. To account for this escalation r.elative to the general inflation rate, a fuel cost escalation rate must be established for project evaluation. Various fuel cost escalation rates over varying periods of time have been used in the past to estimate future fuel costs. Most of those proposed in the past have fallen short of what the actual escalation rate turned out to be. According to the Bureau of Labor's statistics for Anchorage (none are available for Scammon Bay), the inflationary increase from 1974 to 1980 was 67 percent compared to fuel cost increases of 156 percent. Based on these data, the annual fuel cost escalation rate (above inflation) was over 11 percent. Although there is little chance that this high of a rate will continue, it does demonstrate the difficulty of estimating fuel cost escalation. For the purpose of this study, the national fuel cost escalation rate developed by the U.S. Department of Energy (DOE) for the 1981 Annual Report to Congress has been adopted. The proposed escalation rate is shown bel 0\'/: YEAR 1980-1984 1985-1989 1990-1995 1996-201 0 ANNUAL ESCALATION RATE 1.9 percent R.O percent 6.2 percent 1.4 percent These increases would result in the following fuel costs at Scammon Bay: 4.1.2 Conservation Descri pti on 1985 1990 1995 2000 $1.88/gal $2.72/gal $3.5l/ga1 $3. 76/gal This alternative requires the implementation of various methods that would reduce or restrict the use of energy. Adding additional insulation, installing storm windows, weather stripping, upgrading the distribution system etc., are the primary methods of implementing this alternative. Some form of load management may also be possible. R: 8/82 21 Impact assessment This alternative has virtually no adverse environmental impacts while having very positive economic and social impacts. If implemented, significant savings in heating costs could be realized by the villages. The impact on electrical use would be slight however, because very little~ if any, electricity is used for heating and the overall village electrical energy use is minimal when compared to larger communities. The cost of electricity is so high that minimizing its use has become a way of life. Conversion of the distribution system from single phase to three phase could reduce the 18 percent distribution loss. However, according to AVEC, the relatively small increase in efficiency, coupled with the small size of system, does not warrant the expense of converting the system. Evaluation Energy conservation is probably the simplest method to reduce overall energy consumption in the village. Although its implementation would have minimal effect on electrical consumption, the benefits from reduced heating costs would be great. Execution of this alternative should be pursued at the earliest possible time. Implementation Responsibility The basic responsibility for implementing this alternative lies with the local residents. To aid in this responsibility and to lessen the burden, various State and Federal programs are available. The State offers energy auditing services, conservation grants, and low interest loans, and the Federal government offers income tax credits. These opportunities should be pursued to the maximum extent possible by the community. 4.1.3 Waste Heat Recovery Description Two forms of potential energy recovery from existing diesel generators are possible. The first is direct waste heat recovery for heating purposes. This is accomplished with the use of heat exchangers which transfer waste heat from the water jacket and exhaust of the diesel generators to another fluid that can be used for hot water or building heating. Direct waste heat recovery requires that the generators be close to the building or water supply being heated, otherwise heat is lost to the atmosphere. The second form is by use of the Rankine Cycle. This system vaporizes a fluid such as freon with the waste heat from the diesels. The freon, which is under high pressure, is then used to drive a turbine which will produce shaft horsepower to turn the generator for additional electrical power. 22 Impact Assessment The primary negative impact associated with waste heat recovery at Scammon Bay would be the relocation of the AVEC diesel generators because their present location is too far from any major building or water supply. Although relocation is possible, it is doubtful that it could be economically justified. even at current fuel costs. Evaluation As mentioned in the previous section, the present location of AVEC's power plant in Scammon Bay is not suitable for direct waste heat recovery. The high school has a 100-kW standby generator that could be used for waste heat recovery for the school, but Alaska State law requires that all sChools purchase their power from existing utilities if present. The Rankine Cycle energy recovery systems are now in the development stage. When they do become commercially available, it will probably only be for units above 1000 kW. Implementation Implementation of a waste heat recovery system would be the responsibility of the village of Scammon Bay in conjunction with AVEC with possible aid from the State of Alaska. 4.1.4 Wind Generation Descr-iption The possib-ility of developing a feasible wind system at Scammon Bay appears relatively good. Although no wind data has ever been gathered at Scammon Bay. it is known that high winds of long duration are common during the winter months. If a wind system were developed it would probably consist of a number of units in the lO-kW range. Based upon Cape Romanzof data, mean yearly wind velocities average 15.6 mph. The wind is predominantly from the northeast during winter months when velocities are the greatest. Although Cape Romanzof data should not be used directly for Scammon Bay due to its higher elevation (434 feet), the mountains in between it and Scammon Bay, and its southwest orientation, it represents the only data source for the area. The general trends in wind speed and duration should tend to apply to Scammon Bay. According to various sources, an economical wind installation is possible when the mean wind velocity ranges between about 12 and 16 mph depending on the size and type of unit, and the degree of sophistica- tion. Simple systems consisting of direct current generators can operate 23 economically at lower wind speeds if the user is willing to use the electricity strictly for d.c. lighting and resistance space or hot water heating. At Scammon Bay, where an electrical system that uses alternating current already exists, it would be necessary to install a wind system that would be compatible with the existing diesel generators. This could be done on a smaller scale with the use of a synchron'ous inverter, which would depend on the existing utility system to control the voltage. One problem with this system is that the total wind generation c~pacity that could be used would be limited to a small portion of the uti1ity 's total output. If too large of a proportion (more than about 25 percent) was produced by the wind system, the utility could no longer control the voltage. A wind generation system that would be fully compatible with the existing diesel generation system and that could operate as the prime power source for the utility, may double or even triple the cost of the cheaper units. No systems of this type are currently functioning in Alaska and their ability to function in the Scammon Bay climate is unknown. Evaluation To prove feasible, a wind generation system of the type needed for total compatibility with the existing generation system would probably need mean monthly wind velocities in excess of 15 mph. Using Cape Romanzof data, mean velocities in excess of 15 mph occur from October through April. Although diesel generation could not be totally displaced by wind generation because of the need for standby generation during periods of calm, it appears that it could displace a significant amount of diesel fuel, particularly in the winter months,. However, until wind data is acquired at Scammon Bay, it is impossible to accurately assess the actual potential or attempt to optimize a wind system design. Implementation Responsibility Implementation of this alternative would be the responsibility of Scammon Bay in conjunction with AVEC, with possible aid from the State of Alaska or the Department of Energy (DOE). According to comments provided by the U.S. Department of Housing and Urban Development (HUD) on the draft report, pre-application for six 2-kWh wind generators have been received. However, subsequent conversations with HUD indicate that funding is unlikely. 4.1.5 Hydroelectric Description This alternative consists of a rockfil1ed gabion dam with a top elevation of 600 feet, 3,500 feet of 12-inch steel penstock, and a 10x1l-foot powerhouse containing one 100-kW impulse turbine. Based on 24 avail abl e streamflow data, the estimated annual energy output from the system is approximately 409,000 kWh, of which 229,000 kWh (56 percent) is estimated to be usable in 1984, the first year of operation. The other 44 percent is produced during the summer and would exceed the cOlJlllunity's current demand. Diesel generation would be required as a supplement when inadequate flows exist to meet demands. A detailed discussion of the plant sizing is included under the section TECHNICAL ANALYSIS. Impact Assessment Adverse environmental impacts associated with this project are relatively minor in nature. No fish utilize the small stream where the project would be located. Minor disruption of nesting and rearing shore birds may occur during project construction. Special care would be necessary during project construction to confine work to nonpermafrost areas. Social impacts would be positive over the life of the project because a capital intensive hydropower project would tend to hold down electricity costs in the long run, although initially they may be more expensive, depending on the ultimate means of financing. Evaluation A summary of the associated costs and benefits for the hydroelectric system are shown in Table 4.1. The analysis is based on October 1982 price levels, a discount rate of 7-7/8 percent and a 50-year project life. The benefits are based on the direct displacement of energy that would have to be produced by diesel fuel to meet estimated demands. Figure 4.1 shows the relationship of available hydroelectric energy versus estimated demand. The benefits provided by the hydroelectric system at Scammon Bay were determined strictly by the displacement of fuel and the savings in operation and maintenance on the diesel generator. No credit was given for displacement of diesel capacity since the hydropower system would not operate during the peak demand months. The savings in diesel fuel was computed from a 1982 cost of $1.68/gallon, that was escalated until 2010, according to DOE's estimate. Credit was also given to the project based on its ability to meet the estimated 4.5 percent yearly increase in demand. Savings in Operati on and r~ai ntenance was credi ted at the rate of 6. Sst/kWh. R: 8/82 25 100 90 80 en 70 0:: ::) ~60 I r-50-....-_ ~ ~40 C!) w ~30 20 10 O~J~A-N~F~E~B~M-A-R~A~P~R~M~A~Y .. JU-N~MJ-U~L~AU-G~-SE~P~OC~T~N-O~V~~DE~C~ MONTH FC\Hd HYDROPOWER OUTPUT ~ ENERGY DEMAND FIGURE 4.1 SCAMMON BAY, ALASKA ESTIMATED MONTHLY ENERGY DEMAND AND HYDROPOWER OUTPUT (100 k W) FOR 1984 ALASKA DISTRICT, CORPS OF ENGINEERS FEBRUARY 1982 - Table 4.1 Project Costs And Benefits :<: \'l1iitJ, / Annual costs f\} L-b' First Cost Interest and Amortization (7-7/8% @ 50-yrs) Interest During Construction Operation and Maintenance Total Annual Cost Annual Benefits Diesel Displacement Benefit Fuel Escalation Benefit Operation and Maintenance Benefit Employment Total Annual Benefits Net Annual Benefits Benefit-Cost Ratio Implementation Responsibility $1,483,000 120,000 3,000 22,000 $ 145,000 $ 70,000 52,000 23,000 25,000 $ 170, 000 $ 25,000 1. 2 to 1 i~,(1tV Various options are possible for the implementation of this alternative. Under all scenarios it is anticipated that the local utility would be responsible for the operation of the plant. The options available are listed below: 1. Construction by the Corps of Engineers with Federal funding. 2. Construction by the Corps of Engineers with State or local funding. 3. Construction by a private firm with State or local funding. R: 8/82 27 4.2 SUMMARY OF ALTERNATIVE PLANS 1 • Plan Descri~tion Without Condition Al ternati ve A Alternative B Total diesel elec-Hydroelectric plus Wine:! plus trical generation diesel generation diesel genera- tion 2. Im~act Assessment A. Economic Impacts Total Benefits/yr. None $170,000 Insufficient infonnation exists to assess the economics of of a system that could functi on wi th N the Scal1l11on Bay Q:) uti 1 ity. No simil ar system currently exists in Al aska. Total Cost/yr. $145,000 Benefit/Cost Ratio N/A 1.2 Property Val ues No Change No Change No Change Tax Revenue N/A N/A N/A Regf ona 1 Growth No Change No Change No Change Employment No Change There wOlJlrl be a few Same as Al ter- short term jobs during native A constructi on. Business Activity No Change Temporary increase due Same as Al ter- to construction activity. native A Displacement Homes, etc. N/A All construction would be Same as Al ter- () in areas devoid of housing. nati ve A () B. Environmental Impacts Archeological Water Quality Water Quant ity Air Pollution Natural Resources 4.2 SUMMARY OF ALTERNATIVE PLANS CON'T Without Condition No Impact No Change No Change No Change Continued consump- tion of fossil fuel for total electrical generation need. A lternat i ve A No archeological sites have been identified in project area. Temporary increase in turbidity during construction. Reduction at point of village withdrawal, but operation should not affect village water supply. An increase in particulates would occur during con- struction, no long term effects would occur. Construction activities would temporarily in- crease the use of fossil fuels. The project would reduce fossil fuel dependence. Alternative B Same as A lter- native A No Change N/A . Same as A lter- native A Same as A lter- native A w o Lands Habitat C. Social Impacts Noise Displacement of People Esthetics Community Growth and Cohesion () 4.2 SUMMARY OF ALTERNATIVE PLANS CON'T Without Condition No Chiinge No Change No Change No Change No Change No Change A lternat i ve A Construction to take place within the imme- diate vicinity of the stream to minimize permafrost damage. Minor temporary dis- turbance of certain birds during construc- tion. Slight increase during construction followed by a decrease once project is on-line. No Change No adverse visual effects in town, minor adverse visual effects at site. No Change Alternative B Care must be taken to avoid permafrost damage during construction. Same as A lter- native A Same as A lter- native A except wind generators may continue to produce noise. No Change Definite ad- verse visual effects at town site. No Change w ...... () 3. Plan Evaluation 4.2 SUMMARY OF ALTERNATIVE PLANS CON'T Without Condition Under existing con- ditions, Scammon Bay residents will con- tinue to use fossil fuels for total electrical genera- tion. This will cause increasing electrical genera- tion costs as well as a dependence on imported petroleum products. Alternative A Hydroelectric generation along with diesel fired generators complement one another. During hydroelectric genera- tion fossil fuel depen- dence would be reduced. Hydroelectric generation is seasonal depending on streamflows. Alternative B Assuming favorable wind conditions, wind generation is capable of lessening foss; 1 fuel de- pendence parti- cularly during the winter months. Lack of wind data make this a lternat i ve questionable; however, it appears to warrant further investigation and data gathering. (') 4.3 tJED PLAN Federal water resource development policy requires that the alternative providing the greatest amount of net benefits be designated the National Economic Development Plan (NED). For Scammon Bay, the NED Plan is hydroelectric. It would provide net benefits of $25,000 annually. 4.4 EQ PLAN Federal water resource development policy also requires the designation of an Enviromental Quality Plan (EQ). This should be the plan that makes a net positive contribution to the environmental quality of the area. In the case of Scammon Bay, no plan has any significant environmental impacts; however, neither does any plan make a net positive contribution to the environment. Therefore, no EQ plan can be designated. In this case it is necessary to establish an LED Plan (Least Environmentally Damaging). Although the diesel system produces exhaust and noise, it is already in existence and no additional construction would be required, therefore it is designated as the LED Plan. 4.5 SELECTED PLAN The Selected Plan should be the plan that is the best overall scheme to meet national and local objectives. For Scammon Bay, the hydro- electric system is designated as the Selected Plan. This plan is capable of producing approximately 409,000 kWh per year on the average, of which 229,000 kWh is estimated to be usable the first year of operation. R: 8/82 32 CONCLUSIONS AND RECOMMENDATIONS 5.1 CONCLUSIONS Based on the analysis contained in this report, hydropower provides the best alternative for electrical generation at Scammon Bay. In addition to providing net benefits of $25,000 annually, other benefits, which were not quantified in this study include, 1) reducing the quantity of diesel fuel shipped to Scammon Bay (this may reduce the number of shipments, and consequently reduce the handling problems and cost), and 2) providing a buffer to allow for late or insufficient fuel shipments due to either physical or economic constraints. A detailed analysis of the hydropower al ternati ve is i ncl uded under Secti on T, TECHtHCAL ANALYSIS. Wind power appears to hold promise, particularly in the winter months when stronger winds of longer duration occur. Based upon the wind data from Cape Romanzof and an assumption that the general trends hold true for Scammon Bay, wind could prove to complement the hydropower system. During the summer months when hydropower is at its peak, wind generation potential is poor. During the winter, when hydropower potential is poor, wind potential is high. However, before a more accurate determination of exact potential can be made, a continuous recording anemometer should be installed. The State Division of Energy and Power Development may be able to provide assistance to Scammon Bay through their anemometer loan program. Weatherizing through insulation, storm windows, and weather stripping could provide significant savings to the community in the area of home heating. Any effect on electrical demand would be small. This option should be pursued to the maximum extent possible by the village. Upgrading of the distribution system does not appear to be feasible .. at this time. However, if Scammon Bay should show unexpected growth and fuel costs continue to escalate at a rate similar to the past few years, the incremental reduction in distribution losses may warrant conversion to a three phase system. 5.2 RECOMMENDATION I recommend that the Scammon Bay Hydroelectric Project be authorized for construction \'/ith such modifications that may be advisable made at discre- tion of the Chief of Engineers. Design and Construction t4anagement would be the responsibility of the Corps of Engineers with an estimated first cost of $1,483,000, which is subject to cost-sharing and financing arrangements satisfactory to the President and Congress. Authorization of this project for Federal implementation should not preclude the development of hydroelectr'lCnfaciJitjes at---.this-..stte.by a qualified nonferleral interest. ;:) £7./ ;---- ~ f~/t/----_ LEE R. NUNN Colonel, Corps of Engineers District Engineer 33 R: 8/82 - ,- NPDPL-PF (31 March 1982) 1st Ind SUBJECT: Small Hydropower Interim Feasibility Study, Scammon Bay, Alaska DA, North Pacific Division, Corps of Engineers, P.O. Box 2870, Portland, OR 97208 27 May 1982 TO: Chief of Engineers I concur in the conclusions and recommendations of the District Engineer. ~~~~~~~~~~~ MES W. VAN LO N SELS riqadier General, USA Commanding 34 T.1 GENERAL SECTION T TECHNICAL ANALYSIS The selected plan for hydropower development at Scammon Bay is a run-of-the-river diversion project which has a capacity of 100 kW. The project consists of a 50-foot-wide rockfi11ed gabion dam with its crest at 600 feet elevation, 3,500 feet of 12-inch buried steel penstock, and a 10x11-foot powerhouse with one 100-kW rated impulse turbine unit. This system would provide most of Scammon Bay's current energy needs for approximately 7 months of the year. In late fall it would be necessary to supplement it with diesel. For approximately 5 months of the year it would be shut down due to inadequate streamflow. The system could generate an average of approximately 409,000 kWh of an electricity annually at an estimated first cost of $1,483,000, with total annual benefits estimated at $170,000. A detailed description of the design considerations and parameters follows. T.2 HYDROLOGY T.2.1 Basin Description The three-quarter-square-mi1e drainage basin varies in elevation from 600 feet at the damsite to almost 1,300 feet at the highest point. Upstream of the damsite, the basin is covered with wet, spongy tundra, which has a tendency to retain water and release it over a period of time. T.2.2 Streamf10ws The village has historically acquired its water supply from the creek which flows from the Askinuk Mountains. In 1976, the Public Health Service (PHS) built a community water system that treated the water with chlorine and fluoride. Although the village utilizes a portion of the creek for water supply, there are no records of the amount of streamflow which has actually occurred. During July 1980, a water measurement structure (Parshall Flume) was installed to collect data during the upcoming year and to verify the assumed streamflow values. The flume was installed downstream of the PHS water supply intake and consequently does not include water diverted for domestic use. The measured flow at the flume was correlated with the streamflow at the proposed damsite by measuring the flow at the damsite and determining a correlation coefficient. R: 8/82 35 Table T.l shows the computed ,damsite discharges based on flows measured at the flume between July 1980 and July 1981. Table T.l COMPUTED DAMSITE DISCHARGES (July 1980 -August 1981) Based on discharge measurements at the flume downstream of the dams ite. Di scharge Month (cfs) 1980 Jill 2.0 Aug 2.0 Sep 1.4 Oct 1.5 Nov 0.9 Dec 0.6 1981 Jan 0.6 Feb 1.1 Mar 1.2 Apr 5.0 May 10.0 Jun 6.0 Jul no available data Aug 2.0 Based on precipitation data for Cape Romanzof, which is located approximately 15 air miles west of Scammon Bay, it appears that the data for streamflow at Scammon Bay reflects a period of low precipitation for the area. Table T.2 compares average and actual temperature and average and actual precipitation for the period in question. 36 ~ -' rn l- i o -' :.:: 140 40 20 AG-FPP 1479-82 20 rn l- I-« :.: 0 -' :.:: 40 120 APRIL ESTIMATED FROM MAY 1981 DATA HYDROPOWER OUTPUT -------------------125kW MAY HYDROPOWER OUTPUT --------------------125 kW I~,.....-'\-~----------------100kW 100 I+--~-----------------100kW 80 60 40 2 20 JULY 60 80 40 60 80 PERCENTAGE OF TIME HYDROPOWER OUTPUT 100 rn I-- I-- ~ 9 :.: 60 40 2 75 kW 50 kW 40 2 100 20 AUGUST INTERPOLATED FROM JULY 1981 AND SEPTEMBER 1981 DATA 20 HYDROPOWER OUTPUT --------IOO,125l~, 100 75 kW 40 PERCENTAGE OF TI ME SEPTEMBER 40 20 20 PERCENTAGE OF TIME 40 60 80 PERCENTAGE OF TIME 40 60 80 PERCENTAGE OF TIME rn I-- I-- <[ ~ 9 :.: 40 20 JUNE INTERPOLATED FROM MAY 1981 AND JULY 1981 DATA _______________________ 125 kW rn I-- ~ o -' :.: ---------------.------100 kW "'"-.~_-----------------75 kW 20 o 40 60 80 PERCENTAGE OF TIME OCTOBER 40 PERCENTAGE 100 FIGURE T.I SCAMMON BA~ ALASKA ESTIMATED LOAD DURATION CURVES AND HYDROPOWER OUTPUT ALASKA DISTRICT, CORPS OF ENGINEERS MARCH 19B2 -'-' Month 1980 Jul Aug Sep Oct Nov Dec 1981 Jan Feb Mar Apr May Jun Jul Aug Average Temperature 48.2 49.2 43.7 31.1 22.6 12.8 12.9 9.7 13.5 20.7 34.4 43.3 48.2 49.2 Table T.2 CAPE ROMANZOF MONTHLY RAINFALL AND TEMPERATURE July 1980 -August 1981 Actual Temperature 50.0 47.2 44.2 33.7 25.0 8.9 19.8 12.0 25. 1 27.7 42. 1 47.2 48.4 48.8 Average Precipation 2.95 5.00 4.62 2.39 1. 56 1. 21 1.11 0.98 1. 25 0.97 1. 28 2. 13 2.95 5.00 Actual Precipation 4.79 2.27 3.60 1. 50 0.50 0.86 1. 33 1. 70 0.72 1. 27 1. 32 2.01 1. 81 3.85 Table T.2 indicates that the average air temperature is below freezing during the months November through April. Precipitation that falls during this time interval will generally accumulate on the ground as snow or ice and not enter the system for hydrologic power generation until April or May. Instream flows during November through March are largely due to groundwater with some periodic melting. During late April, May, and June, the runoff is relatively high due to melting snow and surface runoff. ~ased on the prevailing temperatures, it appears that the primary ground water recharge will take place between May and September. A statistical analysis of the Cape Romanzof precipitation data for 1981 indicates lower than average precipitation. However, the measured streamflow at Scammon Bay for the correspondin9 summer months in 1980 and 1981 was quite similar. This would indicate a stabilizing effect of the ground water runoff for this basin. Based on the Cape Romanzof precipitation data it appears the low precipitation experienced during the study period will have a return interval of approximately 15 years. During the 23 years of record the recorded precipitation at Cape Romanzof has twice been lower than was recorded during the summer data gathering periods. 37 Difference from Avq +1.84 -2.73 -0.98 -0.85 -1.06 -0.35 +0.22 +0.72 -0.53 +0.30 +0.04 -0.13 -0.75 -1. 15 The measured discharge for Scammon Bay shows an increase beginning in February 1981. It is more typical for Alaskan streams to show an increase in melt season discharge in April or May. This increased discharge may be a reflection of the above average temperatures which the area experi enced between January and June 1981. Scammon Bay di scharge measurements should be continued to establish the typical monthly flow regime used for design purposes. The proposed hydropower plant at Scammon Bay would operate during the months when the average flow is above 1 cfs. This would provide sufficient flow for water supply at the downstream infiltration gallery. Based on the actual correlated streamflow for 1980-1981, a 100-kWh plant could produce the following output: Table T.3 Potential Hydropower Output -Actual Correlated Flows (1980-1981) Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Di scharge (cfs) 0.6 1.1 1.2 5.0 10.0 6.0 2.0 2.0 2.0 1.5 0.9 0.6 Energy MWh -0- 24.2 29.0 72.0 74.4 72.0 46.9 46.9 32.4 35.7 -0- -0- Total 433.5 Due to the increased flows in February and March, which were probably caused by the warmer weather and the lower than normal precipitation, the recorded flows were not considered to be indicative of the average. Therefore, some adjustment was considered necessary to obtain a more realistic base for project evaluation. 38 ~ ,I .......,~;,,'li Table T.4 shows the adjusted discharge and energy figures that were used for project evaluation. Table T.4 Potential Hydropower Output -Adjusted Discharge Energy Month (cfs) MWh Jan 0.6 -0- Feb 0.6 -0- Mar 0.9 -0- Apr 5.0 72.0 May 10.0 74.4 Jun 6.0 72.0 Jul 2.0 46.9 Aug 2.4 55.8 Sep 2.0 45.4 Oct 1.8 42.4 Nov 0.9 -0- Dec 0.6 -0- Total 408.9 The adjustments eliminated any generation from November through March. Although some generation may be possible during these months, it would not be considered typical. Additional adjustments were made to the discharge and energy figures for August, September, and October. These adjustments represent an average increase of slightly over 0.4 cfs for the 3-month period. The adjustments were made to reflect the lower than average precipitation recorded during this period. The actual post project flows could be greater once intergravel flows are cut off by the dam; however, thi sis imposs i b 1 e to quantify at thi s time. T.2.3 Sedimentation No sediment transport studies were done at Scammon Bay. The discharge during the majority of the year is very clear. The only known time when the water has any sediment entrained is during the spring runoff. The particle size is probably fairly large and therefore drops out of suspension quickly as the velocity decreases. Some minor maintenance would be needed at the damsite on a yearly basis. T.2.4 Snow And Ice Problems During the winter months, windblown snow is deposited in the ravine through which the stream flows. In places, the windpacked snow reaches depths in excess of 10 feet by the end of winter. 39 A site visit during January 1981 found that the snow had a tendency to drift from the left side to the right, looking downstream. This trend made the left side somewhat barren while the right side had deep windpacked snow. In the middle of the ravine there was in excess of 100 inches of snow, while on the left side there was about 36 inches. The bank on the left side had places where the tundra was visible. Three snow samples were taken slightly upstream of the village and another three samples taken below the proposed damsite. The average water content was 35 percent. The deep snow along the stream acts as insulation allowing the stream to flow (on a restricted basis) when other streams of similar size are long since frozen. This same dense snow that provides insulation also is subject to creep. Because of the creep potential and the fact that access to the penstock would be restricted for nearly half a year due to snow, a buried penstock is preferred to one located above ground. Special design considerations are necessary to account for low winter flows, frazil ice and potential penstock icing problems. These are considered in more detail later in the report. T.2.5 Power Potent i a 1 Table T-5 provides a summary of the average power potential of 50, 75, 100, and 125-kW units. The smallest unit would not meet peak demands even during the first year of operation. On the other hand, the largest unit would not function efficiently during minimum demand periods. The possibility of installing two units was considered during earlier studies; however the extra cost could not be justified. One unit in the range of 100 kW was found to meet most minimum and maximum demands at significantly lesser cost. Table T.5 Average Capacity and Energy Production 50-kW Unit 75-kW Unit 100-kW Unit 125-kW Unit Month kW kWh kW kWh kW kWh kW kWh Oct 50 37,200 57 42,400 57 42,400 57 42,400 Nov ------------------------ Dec ------------------------ Jan ------------------------ Feb ------------ ------ ------ Mar ------------ ------ ------ Apr 50 36,000 75 54,000 100 72,000 125 90,000 May 50 37,200 75 55,800 100 74,400 125 93,000 Jun 50 36,000 75 54,000 100 72,000 125 90,000 Jul 50 37,200 63 46,900 63 46,900 63 46,900 Aug 50 37,200 75 55,800 75 55,800 75 55,800 Sep 50 36,000 63 45,400 63 45,400 63 45,500 Total 256,800 354,300 408,900 463,600 40 ~ ~ . - To optimize the turbine size, the information in Table T.5 was compared with the energy demand for the months of April through October, shown of Figure T.l. These load duration curves were developed with the aid of information supplied by AVEC for 1981. The actual load duration curves may vary from year to year, but this approximation is the best available using existing data. The estoimated usable energy is stated in tabular form in Table T.6. Note that during the first few years the 125 kW unit actually displaces slightly less energy than the 100-kW unit. This is due to the larger units inability to operate efficiently at the minimum loads projected. Table T.6 Estimated Yearly Usable Energy Unit 1984 1985 1990 1995 2000 2010 50-kW 202,000 206,000 225,000 234,000 244,000 244,000 75-kW 226,000 234,000 272,000 302,000 329,000 329,000 100-kW 229,000 236,000 278,000 314,000 342,000 342,000 1 25-k1J 226,000 234,000 279,000 321,000 359,000 359,000 Diesel displacement benefits were claimed for the portion of the curve in Figure T.1 that is under the average output of the respective hydropower systems. Al though the hydropower output \'1oul d vary over the month, the limited data precludes a more rigorous analysis. The value of the diesel energy that was determined to be displaced by the hydropower system was calculated in accordance with the analysis outlined in section 4.1.1 of the main report. That is, the base 1982 diesel cost of 1.68/gallon was escalated at the presribed DOE escalation rates. These new values, plus the operation and maintenance benefits, were then applied to the energy that the hydropower unit would displace. These annual figures were then present worthed to the power-on-line date using the Federal discount rate of 7-7/8 percent over 50 years. This present worth figure was then converted to an annual cost by applying the same discount rate over 50 years. This represents the average annual cost of the diesel that would be displaced by the hydropower system. The total cost of the hydropower system was then determi ned by taki ng the total first cost and applying 7-7/8 percent discount rate over 50 years to determine the average annual cost on a comparable basis with the diesel being displaced. An .additional figure of $22,000 was added to account for operation and maintenance on the hydropower system. The cost for the hydropower system was then compared to the cost of the energy from the diesel system. The costs from the diesel system become benefits if the hydropower system is installed. A summary of these costs and benefits is shown in Table T.7. Em~lOyment Benefits. NED employment benefits would occur due to construc- tion 0 the Scammon Bay Hydropower Project. Based on data provided by the Alaska Department of Labor and the eligibility criteria described on page 44 of the WRC Reference Handbook for FY 1982, the Wade Hampton census division (in which Scammon Bay is located) does qualify as an area of IIsubstantial and persistent ll emp10yment, as demonstrated below • R: 8/82 41 Criteria 1 -To meet this criteria, the current calendar years' unemp10y-.~ ment must exceed 6 percent. The 1981 annual stati sti cs for Wade Hampton '...., revealed a 10.2 percent unemployment rate. Therefore, Wade Hampton meets this c riteri a. Criteria 2 -To meet this criteria, the unemployment rates must exceed 150 percent of the national average for three of the last four calendar years. Unemployment rates for Wade Hampton for the four preceding calendar years are: 11.1% for 1978,9.0% for 1979,10.7% for 1980, and 10.2% for 1981. Unemployment rates which are 150 percent of the national average are: 9.0% for 1'978, 8.7% for 1979, 10.65% for 1980, and 11.25% for 1981. The actual Wade Hampton unemployment rates exceed these in three of the last four calendar years (1978, 1979, and 1980), therefore it is an leligib1e" area. The Public Works Impact Program (PWIP) allows 43 percent of the amount earned by local skilled labor and 58 percent of the amount earned by local unskilled labor to be used in the NED employment benefit calculation. These percentages are allowable in the case of Scammon Bay due to the existence of a State local hire law #3610 and the hiring practices of the Regional Native Corporati on as di rected by Federal Executi ve Order 1124, U. S. Department of Labor. The census area population of Wage Hampton is 4,665 and had a labor force (insured) of 1, 1?4 and an unemployment rate of 17 percent for the quarter ending r~arch 1982. Unemployment among native groups in general is much higher, suggesting that some of the skilled labor required by the project and some of the unskilled lahor can come from the villages of western Alaska. It is estimated that 60 percent of the project costs would go to labor which would be 35 percent skilled and 65 percent unskilled. Employment benefits for the Scammon Bay project are based on the fo11 owi ng assumpti ons: a. '1ost the skil1erl labor \l/ou1d be imported by the contractor. b. Unski 11 ed 1 abor l'Iou1 d be transported from several western Al aska villages to \'/ork on the Scammon Bay project. c. The unskilled labor requirement would be supplied by area workers. Labor analysis procedures are taken, from guidelines given in Section 713.1207 of the WRC planners manual. Project construction would take advan- tage of the high unemployment condition experienced among native groups. With the policy of local hire in force the higher percentages can be used for deter- mining the amount of local earnings that can be claimed as an tJED employment benefit. The following table shows the derivation of employment benefits for the project. Employment Benefits Scammon Bay Construction Costs Amount to Labor (60%) 42 $1,278,700 767,000 R: 8/82 . ..- ,;' '-' Tab 1 e T. 7 provides a breakdown of costs and benefits for the various opt i on s. Table T.7 Estimated Costs and Benefits 50-kW 75-kW 100-kW 125-kW First Cost ($) 1,079,000 1,112,000 1,136,000 1,169,000 Annua 1 Cost 50 yrs. @ 7-5/8% ($) 84,400 87,000 88,800 91,500 Operation and Main-20,000 20,000 20,000 20,000 tenance ($) Total Annual Costs ($) 104,400 107,000 108,800 111,500 Annual Benefits Fuel Displacement ($) 44,800 56,400 58,700 59,700 Fuel Escalation ($) 30,100 39,600 42,100 43,400 Operation and Main-15,500 19,500 20,300 20,600 tenance ($) Tota 1 Annual Benefits ($) 90,400 115,500 121,100 123,700 Net Benefits ($) -14,000 + 8,500 +12,300 +12,200 Based on this analysis, the net benefits for the 100 and l25-kW units are approximately the same, although the 100-kW unit appears to have a slight edge. If the estimated load growth falls short or exceeds that anticipated, or if the streamflows vary significantly from the estimates, the optimum unit size could either increase or decrease. For the purposes of this report, a 100-kW unit was chosen for the selected plan because of its ability to pick up minimum loads more efficiently than the 125 KW unit and its availability as a standardized unit. Additional streamflow information may alter this selection slightly during post authorization design work. However, any change would only affect the turbine-generator sizing; the intake and penstock are sized to accommodate units between 50 and 150 kW. T.2.6 Water Supply The Public Health Service (PHS) intake for the village's water supply is located a substantial distance below the proposed damsite. The PHS recommended a minimum flow of 28 gallons per minute (GPr~ or 0.06 CFS) as required for the water supply. This would provide approximately 200 gallons per day per capita which is in excess of the normal requirements of an urban area. The PHS indicated that they believe the actual utilization of the system to be between 50-70 gallons per day per capita. This difference in system capability and actual uti.lization would provide a margin for development within the community. 43 The drainage area between the damsite and the water supply intake is 0.5 square miles which is two-thirds the size of the tributary area to the damsite. By correlating this lower area with the upper drainage basin an approximation of the water available for domestic use can be made as ~hown in Table T.8. 1.8 Water Available for Domes tic Use Available Water Total Water Available Water Available Water From Lower 'Available For I~onth At Damsite Less Hydropower Basin Domestic Use Oct 1.8 0 1.2 Nov 0.9 0.9 0.6 Dec 0.6 0.6 0.4 Jan 0.6 0.6 0.4 Feb 0.6 0.6 0.4 Mar 0.9 0.9 0.6 Apr 5.0 1.6 3.3 May 10.0 6.6 6.7 Jun 6.0 2.6 4.0 Jul 2.0 0 1.3 Aug 2.4 0 1.6 Sep 2.0 0 1.3 Based on the above analysis, adequate water would be available year-around to supply the community's domestic needs. Due to the limited operation of the hydropower system, i.e. April through October, the available water during the critical months of winter is unaffected. If, for some unforeseen reason, the water supply demand did exceed the supply, the planned diversion works are capable of diverting up to 1.2 cfs thrdugh the dam on a controlled basis and could be used to supprement the village's water supply if necessary. During winter shut-down due to low flows, the diversion works would divert all flow through the dam to supplement the village water supply and prevent ice-up of the reservoir. A detailed explanation of the winter diversion scheme is included later in the report. 44 1.2 1.5 1.0 1.0 1.0 1.5 4.9 13.3 6.6 1.3 1.6 1.3 Amount by category Local contribution Earned by locals Claimed as NED benefits Total by category Combined Total Skilled (35%) $ 268,527 20% 53,705 .43 23,093 $312,335 Annual Benefit -312,335 x .0806 = $25,174 Rd = $25,000 Unsk ill ed (65%) $ 498,693 100% 498,693 .58 289,242 Table T.7 provides a breakdown of costs and benefits for the various options. First Cost ($) Annual Cost 50 yrs. @ 7-5/8% ($) Operation and Main- tenance ($) Interest During Construction Total Annual Costs ($) Annua 1 Benefi ts Fuel Displacement ($) Fuel Escalation ($) Operation and Main- tenance ($) Employment Table T.7 Estimated Costs and Benefits 50-kW 1,412,000 114~000 22,000 3,000 139,000 54,000 38,000 . 17,000 24,000 75-kW 1,453,000 117,000 22,000 3,000 142,000 68,000 49,000 22,000 25,000 100-kW 1 ,483,000 120,000 22,000 3,000 145,000 70,000 52,000 23,000 25,000 1 25-kW 1 ,524,000 123,000 22,000 3,000 148,000 71,000 53,000 23,000 Total Annual Benefits ($)133,000 164,000 +22,000 170,000 +25,000 26,000 173,000 +25,000 Net Benefits ($) -6,000 Surplus Energy. During the summer, the project's capacity I'lould exceed Scammon Bay's needs. This surplus energy is estimated to be in excess of 4,200 MWh over the life of the project. If all of this energy were used by a facility such as a cold storage building or for hot water heating, the fuel displacement and escalation benefits would be substantial. Although this type of use is likely in the future, it is difficult to document definite plans for use of surplus energy at this time. Based on this analysis, the net benefits for the 100 and 125-kW units are approximately the same~ If the estimated load growth falls short or exceeds that anticipated, or if the streamflows vary significantly from the estimates, R: 8/82 45 the optimum unit size could either increase or decrease. For the purposes of ~ this report, a 100-kW unit was chosen for the selected plan because of its ~ ability to pick up minimum loads more efficiently than the 125 KW unit and its availability as a standardized unit. Additional streamflow infonnation may alter this selection slightly during post authorization design work. Hm'lever, any change would only affect the turbine-generator sizing; the intake and penstock are sized to accommodate units between 50 and 150 kW. T.2.6 Water Supply The Public Health Service (PHS) intake for the village's water supply is located a substantial distance below the proposed damsite. The PHS recommended a minimum flow of 28 gallons per minute (GPM or 0.06 CFS) as required for the water supply. This would provide approximately 200 gallons per day per capita whi ch is in excess of the nonnal requi rements of an urban area. The PHS indicated that they believe the actual utilization of the system to be between 50-70 gallons per day per capita. This difference in system capability and actual utilization would provide a margin for development within the community. The drainage area between the damsite and the water supply intake is 0.5 square miles which is two-thirds the size of the tributary area to the damsite. By correlating this lower area with the upper drainage basin an approximation of the water available for domestic use can be made as shown in Table T.8. T.8 Water Available for Domestic Use Available \~ater Total Water Available Water Available Water From Lower Available For Month At Damsite Less Hydro~ower Basin Domestic Use Oct 1.8 0 1.2 1.2 Nov 0.9 0.9 0.6 1.5 Dec 0.6 0.6 0.4 1.0 Jan 0.6 0.6 0.4 1.0 Feb 0.6 0.6 0.4 1.0 Mar 0.9 0.9 0.6 1.5 Apr 5.0 1.6 3.3 4.9 May 10.0 6.6 6.7 13.3 Jun 6.0 2.6 4.0 6.(; Jul 2.0 0 1.3 1.3 Aug 2.4 0 1.6 1.6 Sep 2.0 0 1.3 1.3 Based on the above analysis, adequate water would be available year-around to supply thecommunity's domestic needs. Due to the limited operation of the hydropower system, i.e. April through October, the available water during the critical months of winter is unaffected. If, for some unforeseen reason, th,e water supply demand did exceed the supply, the planned diversion works are capable of diverting up to 1.2 cfs through the dam on a controlled basis and could be used to supplement the village's waterSIJpp1y if necessary. During winter shut-down due to low f1m'ls, the diversion works would divert all flow ~ through the dam to supplement the village water supply and prevent ice-up of ~ the reservoir. A detailed explanation of the winter diversion scheme is included later in the report. 46 PUBLIC HEALTH SERVICE WATER SUPPLY ABOVE SCAMMON BAY PROPOSED SITE FOR HYDROELECTRIC INTAKE STRUCTURE 80-82 - T.2.7 Potential Floods An analysis of data from Moody Creek at Aleknegik (STA. 15-3029-00) was utilized to estimate potential floods. The drainage area above the damsite at Scammon Bay is approximately 0.75 square miles while the drainage area at Moody Creek is 1.28 square miles. Although Moody Creek does not have the same coastal influence that Scammon Bay does, it was believed that Moody Creek was the b~st station in the area to use. Its frequency curve is ill ustrated in Fi gure 5.1 The Scammon Bay di scharges for various frequencies are illustrated below in Table T.9. These discharges were determined by a comparison of the drainage areas between Scammon Bay and Moody Creek. T.2.8 Dam Safety Table T.9 SCAMt101~ BAY DISCHARGE FREQUENCIES Return Internal (yrs) 200 100 50 25 10 5 2 Di scharge Q (cfs) 135 104 82 65 49 39 27 The "Recommended Guidelines for Safety Inspection of Dams," provides general criteria for evaluating the safety of dams. Since the actual storage is less than 50-acre-feet and the height of the dam is less than 25 feet, the site classification would be considered "small." The fail ure of the dam would not be expected to cause any "loss of 1 ife" or cause any "economic loss," by flooding. These conclusions result in a hazard potential classification of "low." In actuality, the reservoir storage capacity is so small (approxi- mately 1/10 acre-foot) that any dam failure would not significantly change the downstream flow. Any adverse effects on the dam itself due to flooding \'/ould probably be limited to siltation requiring additional maintenance. The blo classifications of small size and low hazard potential result in a recommendation by the guidelines for a Spillway Design Flood (SDF) of between a 50 to 100-year frequency. A 100-year discharge (104 cfs) was used. No damage would be anticipated at the powerhouse due to location above the 100-year floodplain. However, damage to the village water supply could be expected where it crosses the stream below the powerhouse 49 site. Two existing culverts pass the streamflow through the road embankment that supports the water lines. These culverts are inadequate to pass the design flow. 50 - T.3 GEOLOGY T.3.1 Project Site Geology Local rock is a granodiorite intrusive of probable Tertiary Age. Deep weathering, jOinting, exfoliation and/or frost spa11ing have produced surface bou1 der fi e1 ds and thi n si 1 ty soi 1. Unsorted gl aci a1 overburden overlies the granodiorite bedrock in the project area. The overburden represents ground moraine with interdispersed water-lain deposit. The glacial overburden consists of gravel and sand containing numerous cobbles and boulders. Composition of the gravel, cobbles, and boulders is primarily granitic. The granodiorite bedrock and granitic glacial overburden weathers quite rapidly due to the climate and mineral- ogical composition. The glacial overburden varies in thickness through- out the area due to the undulating granitic bedrock surface. In the vicinity of the damsite at the 600-foot elevation, the overburden is approximately 8 to 10 feet thick. Near the powerhouse site, overburden varies between 6 and 20 feet. Overburden thicknesses were determined using refraction seismology. Permafrost is absent to sporadic w.ithin the immediate project areas. The perennial spring-fed stream and the predictable thick insulation blanket of drifted winter snow within the stream gully results in a thaw zone beneath and adjacent to the stream. Outside of the gully, the surrounding area is underlain by continuous permafrost. Bank erosion is prevalent on streambank slopes between the village and its water supply intake. This is probably due t~ summer thaw of the active layer. The west bank of the stream, between the village and water supply intake, has a low profile due to subdued erosion. This condition probably causes thinner winter snow drifts to accumulate in the area, hence more exposure to prolonged below freezing temperatures. The powerhouse site is located in an area above the stream where solifluction does not appear to be a problem. T.3.2 Material Sources The borrow area, located on the east edge of Scammon Bay, was sampled and tested for quality of concrete aggregate. Analysis of the test results indicated that the fine and coarse aggregates are of relatively poor quality and will not meet Corps' standards for approval. The exposed granodiorite outcrop near the site could possibly produce quality aggregate, however, more testing is needed. T.4 DAt1, SPILLWAY, AND INTAKE T. 4.1 Descri pti on The dam would be constructed of rockfilled gabions arranged around a cutoff wall that extends into bedrock. This cutoff wall would be 51 constructed of sackcrete and extend approximately 9 feet below the eXisting ground surface and about 4 feet below the gabions. Layouts of the dam, intake, penstock and powerhouse are shown on Plates 2 through 5. The dam would have a crest length of 50 feet and a maximum height from bedrock of 15 feet. The height above existing ground would be approxojmate1y 7 to 8 feet. The nonoverf10w secti on of thi s gravity structure would have a top elevation of 600 feet. The ungated weir overflow section would have a total length of 13.5 feet at elevation 598. Overflow from the weir would enter the existing streambed. The dam would consist of one row of standard manufactured galvanized steel gabions on the upstream side of the cutoff wall and two rows on the downstream side. These would be set down into the existing streambed. The gabions would be filled with rocks taken from the reservoir excavation and the nearby area. The intake structure would be a square, metal dropbox set vertically on the right bank. A french drain system would run from the left side of the intake to the left abutment. The french drain would consist of clean gravel which would allow flows to enter a perforated pipe in the drain and be carried through the dam via a metal pipe. A blind flange would be mounted on the drain pipe inside the intake structure to allow access for maintenance and entrance of low flows to supplement power production. A gate valve would be mounted on the drain pipe inside the intake structure to allow regulation of flow through the dam. A 2 X 2.5-foot trashrack would he mounted in the side of the intake structure below the elevation of the overflow section. A movable bulkhead would be mounted above the trashrack intake. This would be lowered to dewater the intake or to shutoff the intake during winter shutdown. The grating of the trashrack would be coated with a hydrophobic fluorocarbon to reduce icing. A USGS-style gage house would be placed on top of the intake structure to keep it free of snow and to allow access during periods of deep snow. A ladder would be installed inside the structure to allow access to the valves and instrumentation that would be located inside the structure. T.4.2 Flushing System The oj ntake structure wou1 d not have a f1 ushi ng system because of its small size. The reservoir bottom would be sloped away from the intake toward the center of the small excavated reservoir to prevent rocks and other debris from accumulating around the intake. If excessive material does build up in the channel, the reservoir could be drawn down and the material removed by hand or with a small tractor. T.4.3 Hydraulic Design The weir overflow section in the rock gabion dam is designed to pass the 100-year flow. The overflow section is 2 feet high and 13.5 feet long. 52 The intake structure is designed to operate year-round regardless of flow. During the warmer months when flows are capable of exceeding the power requirements, the water would flow through the trashrack and into the penstock with excess flow being passed over the weir. When the system is shut down in the winter, all flows would be diverted through the dam via the french drain, perforated CMP and drain pipe. This drain pipe would terminate in another french drain downstream of the dam to prevent freezing. During winter operations much of the intake would be covered with snow; however, to what extent is unknown. Anchor ice could form on the penstock, diversion pipe and valves. When the hydropower system is shutdown, the penstock would be drained to prevent failure caused by freezing. T.4.4 Operation Automatic shutoff of the system at a power output of less than 15 kW would be designed into the turbine/generator unit. It would also be designed into the manual operation of the plant. When streamflow drops below 0.63 cfs, the minimum needle valve setting for the turbine, any further drop in streamflow would result in a decrease in head. When net head becomes low enough, power output would drop below 15 kW and the system would shut down automatically; first the jet deflector would divert the flow away from the turbine runner, then the needle valve would close slowly (25 seconds). System shutdown (15 kW output) would occur when gross head reaches about 430 feet and discharge about 0.54 cfs. Since the turbine control mechanism has no way of knowing when the streamflow is high or low, a manual setting of the nozzle for an output of 0.63 cfs with a gross head of 488 feet must be built into the system and must be activated by the operator when streamflow is in the 0.6 to 0.7 cfs range. The same type of manual control must be built in for moderate and high flows since regulation of inflow by load demand alone could cause the penstock to drain unnecessarily. A fail-safe mechanism should also be incorporated into the turbine-generator system to prevent penstock drainage in case of operator error or negligence. T.4.5 Dewatering of Intake Structure The intake structure woul d be dewatered to the penstock invert by lowering the bulkhead and releasing water through the penstock. Minor maintenance could be done at this time and complete dewatering by pumping or other means would allow any major maintenance work. 53 T.5 PENSTOCK T.5.1 Description The penstock would be buried throughout its length. It would run within the confines of the ravine through which the stream flows. The streambed is generally a composition of gravel, cobbles, and boulders that varies from 6 to 20 feet in depth with some outcrops of bedrock. The groundline along the stream bottom has an average slop~ of 13.5 percent. The penstock would cross from the right bank to the left bank of the stream about 550 feet downstream of the dam. The vegetation' cover in the streambed is minimal. The' penstock would be a 12-inch inside diameter steel pipe extending 3,500 feet from the intake invert at the at 589-foot elevation 11 feet below the top of the dam to the powerhouse at 110 feet. The project gross head is 488 feet. A 12-inch diameter manually operated gate valve in, the intake structure would allow the penstock to be drained during winter low-flow conditions and during maintenance. A 1-7/8-inch diameter air vent would extend from the penstock immediately downstream of the gate valve up through the gatehouse to the open atmosphere. A screen would cover the upstream end of the gate valve to insure that no small objects are drawn into the penstock. The penstock would be designed for a minimum working pressure of 440 psi with a minimum wall thickness of 0.188 inches. The penstock would be completely encased in select bedding material to insure against point loading that could develop with boulders and bedrock. In periods of cold weather when frazil ice begins to form in the stream, the downstream valve at the powerhouse would remain open until the penstock was completely drained. Penstock drainage would be accomplished by closing the upstream valve to the penstock and allowing the \'Iater to drai n by defl ecti ng the water away from the buckets of the impulse turbine. This was determined to be the safest and most cost effective method to avoid penstock freezing. Insulation of the penstock was considered, but would only delay the freeze-up for a few hours at a significantly greater cost. T.6 POWERHOUSE T.6.1 Description The lOO-kW unit would have all equipment housed in a 10xll-foot prefabricated, insulated, weather tight, steel structure, built on a 12-inch concrete slab. The powerhouse would be located at elevation 110; the finished floor elevation would be least 3 feet above the maximum tailwater level. An open channel tai'lrace would be excavated below the powerhouse. R: 8/82 54 . ..-Ventilation would be provided by a wall mounted fan. Two fire "~ exti ngui shers wou1 d provi de fi re protecti on to the bui 1 di ng; none wou1 d be provided for the generator. A weather tight, roll-up door would allow access for equipment installation. A 5-ton underhung crane would be .- i nsta 11 ed for equi pment hand1 i ng. A 1 ayout of the proposed powerhouse is shown on Plate 5. T.6.2 Turbine, Generators, and Electrical Description The hydroelectric power generation equipment would be procured as a package unit. It would consist of one impulse turbine, a synchronous generator, governor system, voltage regulator, and protective and control devices. Units of this type are readily available from industry, either as pre-engineered standard or custom designs, covering a wide range of heads and flows, connected loads, and operating conditions. In addition to bei ng economical and simpl ifyi n9 install ati on, package unit procurement reduces the number of supply contracts from three or four to only one. The lOO-kW turbi ne woul d be a "standardi zed" hori zontal axi s impul se or Turgo impulse turbine with one or two adjustable nozzles. The nozzles \-iould be actuated by servomotors controlled by the governor. Jet deflectors would be used for diversion of water from the runner for rapid load change, load rejection, or penstock draining. A cylinder actuated butterfly valve in the penstock would be provided for shutoff of the water. The unit would be specified to produce power over a range of 15 to 100 kW when operating at 430 feet net head. The expected discharge from the turbine at maximum power is estimated to be 3.4 cfs, and 0.63 cfs at mimimum power (l5 kW). A flywheel would be provided, if necessary, to limit speed excursions during load changes. The turbine would drive a generator through V-Belts and a parallel shaft gearbox, or through a direct connection to the generator. The choice of the operating speed and power transmission system would be left to the manufacturer. If the gearbox or V-Belt drives were used however, a 4 percent efficiency loss would be charged to the turbine in the determination of its guaranteed performance characteristic. The governor system would be furnished as an integral part of the turbine-generator package unit. The governor system would be composed of electronic speed sensitive elements (frequency transducer, controller, and amplifier), a servo system consisting of either electric motor and gears or hydraulic pump and electric motor, and the necessary controls. Responding to fluctuations in power demand, the governor would actuate the needle valve in the water supply line, control the amount of water supplied to the turbine and regulate the speed of the unit. The governor size and characteristics (capacity and speed regulation) would be determined by the manufacturer, based on head, WR2, speed, and power of the unit • 55 The synchronous generator would be provided as part of the package unit. The generator, which should be provided with special bearing and lubricants suitable for operation in extended low temperatures, would be rated single phase, 60 Hz, 100 kW {125 kVA @ 0.8 pf}, 120/240 volts with full Class F thermal capacity (Class B temperature rise) and be capable of cont·j nuous operati on at 110 percent overload and + 5 percent of rated voltage. The generator would be equipped with a brush1ess, full wave rotating rectifier excitation system and a saturable transformer type automatic voltage regulator with a response time of 200 milliseconds, capable of regulation of one percent from no-load to full-load. The generator would also be furnished with a control and protection equipment group. This consists of a circuit breaker (with shunt-coil type, under-and-over voltage relays, overcurrrent relay, stator thermal relay, instantaneous ground relay, rec10sing relay, and lockout device), an ammeter, watt-hour meter, watt-meter, volt-meter, frequency meters, and indicator lights for manual synchronization. In order to prevent moisture build-up, it may be necessary to partially energize the system during winter shut-down. The generator bus would be tapped beb/een the generator circuit breaker and the step-up transformer to provide three-wire, single phase 120/240 volts to a lighting distribution panel for service station lighting, convenience outlets, a ventilating fan, and other miscellaneous loads. The main power transformer would be single phase, 120/240 volt primary, 12,470/7200 volt secondary, 15 kV class, dry type, and ventilated. It would be floor mounted in the powerhouse. The generator, excitation, breaker, and turbine controls would be mounted on the governor equipment cabinet. Controls would be included to manually synchronize the excited unit to the line. Metering would be provided for volts, amps, vars and watts. The generators would be provided with voltage restraint overcurrent and overvo1tage relays. Underfrequency and overfrequency protection of customer equipment would be provided with speed switches and some form of automatic time error control would be considered. T.7 TRANSMISSION SYSTEM The electrical connection to the existing distribution system would be by 15 kV, No.2 AWG aluminum conductor on wood poles from the \'/a11-mounted weatherhead fitting at the powerhouse to the existing 7.2 kV primary capable in the surface-mounted duct bank. Rigid steel conduit would be used to run the cable from the terminal pole to a pad mounted terminal cabinet installed in the duct bank. 56 T.8 ALTERNATIVE DESIGNS CONSIDERED T. 8. 1 Dam Various types of dams were considered, but due to remoteness, lack of material sources, and cost they were ruled out. Alternatives considered included concrete (good aggregate source unavailable), earthfill (access difficulties and limited borrow material), and timber (no local source and potential snow creep problems). The chosen alternative, rock filled gabions is suitable for the small size of the dam. Also the availability of suitable sized rock in the project area is good. A sackcrete cutoff to bedrock was used for estimating purposes; however this may be changed to a membrane cutoff during final design. T.8.2 Penstock Alternatives An above ground penstock was considered in addition to the recommended buried penstock. The buried scheme was selected because it would present less long term problems. It would be less susceptable to vandalism, snow creep, freezing and stream activity. The following pipe materials or combinations of pipe materials were considered for both above and underground installation: 1. Schedule 40 steel entire length 2. 0.188 inch steel entire length 3. High density polyethylene + Schedule 40 4. High density polyethYlene + 0.188 inch steel 5. Reinforced plastic mortar pipe entire length Underground installation of 0.188 steel penstock and reinforced plastic mortar (RPM) pipe were found to be the least costly alterna- tives •. The steel penstock was chosen because it presents less unknowns regarding installation and bedding. The remoteness of the location, potential difficulties in bedding, high working pressures and general durability were factors considered in pipe selection. T.8.3 Powerhouse Due to the limited flow and high head, the only suitable turbine type is an impulse turbine. Various sized turbines of 50, 75, 100, and 125 kW were considered. In addition, two 50-kW units were previously considered, but were found to be 1 ess cost effecti ve than one 1 OO-k\~ uni t. The 100-kW unit was found to be the optimun choice based of the parameters of flow, energy demand and cost. R: 8/82 57 T.9 CO~STRUCTION PROCEDURES Due to the delicate nature of the permafrost areas near the project, speci al care \'Ioul d be necessary to assure that these areas are not distul"'bed unnecessarily. Tracked vehicles brought in by the State of Alaska to construct the runway in the early 1970's crossed the permafrost above town when it was unfrozen. This disruption of the vegetative cover reduced its insulating capabilities resulting in the melting of the permafrost. This melting has caused additional loss of vegetation and further melting, resulting in the erosion of gullies nearly 6 feet deep. For construction of the hydroproject, access would be limited to the confines of the ravines through which the stream flows. This area is underlain by a thawbulb in the permafrost. Access over permafrost areas may be allowed for staging materials and equipment if it were done during winter when acceptable conditions of frozen ground and adequate snow cover exist. An equipment access plan would be incorporated into the contract documents. This plan would delineate construction corridors for both summer and winter access. T.10 PROJECT OPERATION AND MAINTENANCE Once constructed the project would probably be turned over to the local utility for operation and maintenance in conjunction with the existing diesel generators. It would be the responsibility of the utility for all maintenance associated with the intake works, penstock, powerhouse and distribution system. In addition, spring startup and winter shutdown including penstock drainage would be required. The unit would be capable of matching the necessary load during the time of year when flows equal or exceed the demand. During those low flow times when energy demand exceeds the capabilities of the system, the hydropower unit would operate in a base load mode while the diesel would be utilized for peaking. 58 PERMAFROST EROSION DURING AIRPORT CONSTRUCTION ~ T.11 PROJECT COST i~ ITEM DESCRIPTION QUANTITY UNIT UNIT PRICE TOTAL MOB & PREP WORK 1 LS $300,000 LANDS & DAMAGES Administrative Costs 1 LS $1,000 Lands 1 LS 4,000 $5,000 DAM, SILL, & RESERVIOR Excavation 230 CY 20 $ 4,600 Sac kc rete 54 CY 600 32,400 Reinforcement 2,700 LB 1.50 4,050 Gabion 216 EA 40 8,640 Rock 144 CY 160 23,040 Backfi 11 18 CY 10 180 Drain pipe 12" II' 90 EF 25 2,250 French Drai n 30 CY 50 1,500 $76,660 INTAKE STRUCTURE Steel Intake 1,224 LB 5.00 $ 6,120 Bulkhead Gate LS 10,000 Trashrack 100 LB 5.00 500 Transducer 1,200 Manometer 600 Gate Valves 12" II' 2 EA 7,900 15,800 Insulated Structure 1 EA 6,400 $40,620 PENSTOCK Steel (12" II' 88,270 LB 2.70 $238,329 0.188" thick) Concrete Anchor 30 CY 600 18,000 and Thrust Blocks Excavation 3,000 CY 20 60,000 Backfill 3,000 CY 30 90,000 $406,329 61 ITEM DESCRIPTION POWERHOUSE Structure Turbines & Generators Auxiliary Systems Switchyard and Distribution System Connection TAILRACE Excavation Riprap SUBTOTAL 20 Percent Contingencies CONTRACT COST QUANTITY LS LS LS LS 45 15 Engineering and Design Supervision and Administration TOTAL PROJECT COST T.12 PROJECT ECONOMICS T.12.1 Federal Criteria UNIT 1 1 CY CY lINIT PRICE 25 120 TOTAL $ 43,000 145,000 18,000 28,000 $234,000 $1 ,125 1,800 $2,925 $1,065,534 213,166 $1,278,700 $ 102,000 102,300 $1,483,000 Under criteria established for Federal water resource projects, the Selected Plan is feasible •. Factors influencing the feasibility have been presented in appropriate sections of the report. The results are presented below: ANUUAL COSTS AND BENEFITS Interest and Amortization (7-7/8% @ 50 yrs) Operation and Maintenance Interest During Construction Total Annual Cost Annual Benefits Fuel Displacement Benefit Fuel Cost Escalation Benefit Operation and Maintenance Benefit Employment Benefit Total Annual Benefit Net Annual Benefit Benefit-Cost Ratio 62 R: $ 120,000 22,000 3,000 $ , 45, 000 $ 70,000 52,000 23,000 25,000 $ , 70, 000 $ 25,000 1 • 2 to 1 8/82 ~ -,' """ ' """ " .. .....:1(111'1": ... ",. r·;·IIP' "iii iCI{,,¥#."-!~OR¥S OF ENGINEERS . t':f ...------------------.,....------------- I CAPE ROMANZOF BAY . \ \ (~OUNTAINS ~ VICINITY MAP SCALE' I" it I MILt ASKINUK MO UN T A INS CLARENCE RHODE NATIONAL WILDLIFE RANGE c J LOCA TION MAP ALASKA DISTRICT CORPS OF ENGINEERS ANCHORAGE, ALASKA SCAMMON BAY, ALASKA 1-.... ...... --1 HYDROELECTRIC PROJECT LOCATION a VICINITY MAP SHEET I INV. NO. DACW85- U. S. ARMY CORPS OF ENGINEERS () \.) -lWii -< m ~ CORPS OF ENGINEERS ANCHORAGE, .ALASKA SCAMMON BAY. ALASKA /-",~_::------t HYDROELECTRIC PROJECT GENERAL PLAN INV. NO. DACW85- U. S. ARMY ~ORPS OF ENGINEERS \ u ) \ \ I T-~ ----. \, ... ~\ ~. ,'>~~S'" ~.~~ . --··~~:s~ DAM LOCATION -Pl...~~--=-~ a;r.;l7O.0 -GoATCHOU5E. '~--_'.""-~ UPSTREAM eL-EVATION ; ! I · i SCA.lE IN rEET / /' _/ / ...------+_ ~L.INc> Fl..o*J(;IO [?ETAIL ® r I ! /' /' /' SCALE I N FEET / /' /' / / ~ / ---- ALASKA DISlRICT CORPS 0,. DlGINDRS ANCHORA ..... ALASKA SCAMMON BAY, ALASKA tm __ ~"""" HYDROELECTRIC PROJECT I"m_~'"""'t DAM AND INTAKE STRUCTURE PLAN. ELEVATION. a DETAIL !CALEo AS SHOWN .. '" ... - INV. NO. DACW85- U. S. ARMY n u CORPS OF ENGINEERS HOI.J'5E----- F'E:,*,T~ \l6l..V~ CONTItOL. PlVEI1<;IOIJ PIPE! VAl-Ye COI'ITlrOL... ~I( 1l'9" PiA. All< VENT----HI-----' VAl-VE 9TlSMS ------II't-- ~u::~----~II ~.5'n.O neo..SH~ ---~-t-H l.X>P~-----_I±f-- EI--594.0 I-------i .•. '. 1-----+------1 l-----i " -1 - .' -e~~~~~~EE~~·o.o:::::d <OCREOliI-J ---/ 12' ; ~ .... re. V-"/..VIO 12" ¢ ~FORATEt>--+""",~J PIP!! TYPICAL "'SPILLWAY "SEcTION o 1 '1 :J 4 ~ u----____ St-.LE IN r[ ET o SECTION EB J SCALE Iii FEET <:LA%lFIIW ---~-/ e.>o:'FIL-L-~J;% COHPACTION 'SECTION d f SCALE 'N FEET AU'.SKA DISTRICT CORPS OF ENGINEERS ANCHORAGE. ALASKA SCAMMON BAY. ALASKA "----~ HYDROELECTRIC PROJECT ,-_.,...::.ptz.'"IDAM AND INTAKE STRUCTURE SECTIONS INV. NO. DACW85- SCAUo AS SHOWN .... '" RLI! NU ..... SH&T4 0.:5 U. S. ARMY ~ORPS OF ENGINEERS o '- I 2 3 ! I ; SC .... LE IN n: [T 4 ! I' TAILP.A<% DeTAl1h TO q,UIT '?I"TE 11~O' . of G!l!IJI!IV<10,.. 100 f',Y./ IZO/Z40 VN:., ,",0101&, l¢.i PLAt-J 1-100 KW U~IT r ! f i U. S. ARMY PO~l"WQJ, fO'<1l~ -tpo ):<; W. HaAD -~ 1"1". ALASKA DISTRICT CORPS OF ENGINEDte ANCHORAGE. Al.A8KA SCAMMON BAY! ALASKA .... __ ---; HYORC£LECTRIC PROJECT "-_ ....... '"-1 SCAMMON BAY POWERHOUSE TRANSVERSE SECTION AND PLAN INV. NO. DACW85· SCALE.AS SHOWN DATE: .... ,.,- ...... 5 OF 5 FINDING OF NO SIGNIFICANT IMPACTS In accordance with the National Environmental Pol icy Act of 1969, as amended, the Alaska District, Corps of Engineers, has assessed the environmental impacts of the following action: SMALL HYDROELECTRIC PROJECT SCAMMON BAY, ALASKA Hydroelectric po~r would be developed from the stream which originates south of Scammon Bay and flows through the village. The stream flows from approximately elevation 800 to elevation 50 where it merges with the main channel of the Kun River. A small reservoir (less than one-tenth of an acre-foot of storage) would be excavated upstream of a rock-filled gabion dam which \\()u1d be constructed with a crest elevation of 600 feet. A penstock \\()uld run 3500 feet from the intake structure of the dam to an aboveground powerhouse with an installed capacity of 100 kilowatts located near the village's school. An open channel tailrace approximately 50 feet in length \\()uld be excavated from the powerhouse to the main stream channel. The estimated flows at the damsite display a high discharge of 10 cubic feet per second in May with a low of 0.3 cubic feet per second during January. These flows could develop about 372,000 kilowatt-hours of electricity annually, of which 275,000 kilowatt-hours is estimated to be us ab 1 e. Scammon Bay is totally dependent upon fuel oi 1 for space and water heating and electrical generation. Increases in fuel prices have been the principal source of the rising costs of electrical power. The average cost of diesel fuel delivered to Scammon Bay has increased almost four fold since 1973. Future demand and scarcity of petrochemical products will cause continued price increases. The Environmental Assessment indicates no significant adverse impacts would occur dur,ing the construction or the operation and maintenance of the proposed project. A letter of intent to prepare a Finding Of No Si gni fi c ant Impact (FONS!) for the proposed project was dis tri buted to the resource agencies for their review and comment. None of the agencies indicated any objection to the preparation of a FONS!. The Environmental Protection Agency and the U.S. Fish and Wildlife Service stated the magnitude of the project and the low levels of wildlife resources in the project area eliminated the need of an environmental impact statement. The environmental review process has indicated to me that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment. Therefore, an environmental impact statement will not be prepared for the small hydroelectric project at Scammon Bay. Alaska. Also, the proposed action does not appear to confl ict with the approved Alaska Coastal Management Program or any other appropriate regulation or program. The Environmental Assessment \tkIich has addressed the proposed action is available from the District Office upon request. DATE fl1 ~t?d--.-It( ///drvh 118',2. LEE R. NUNN' Colonel, Corps of Engineers District Engineer 2 ENVIRONMENTAL ASSESSMENT ~ NEED FOR THE PROPOSED ACTION The Corps of Engineers was authorized by Congress to conduct feasibility studies for the development of small hydroelectric power facilities at i so 1 ated vi 11 ages throughout Alaska. The v'l 11 age of Scammon Bay requested that the Alaska District study the hydropower potential of a small, unnamed spring-fed stream that runs through their village. Scammon Bay, a member of the Alaska Village Electric Cooperative, Inc. (AVEC), is totally dependent upon diesel generation for electric power. Because of the escalating cost of diesel fuel and concern over its availability, alternative power sources, such as hydroelectric power, could be more economical and reduce the use of nonrenewable resources. COORDINATION AND PUBLIC INPUT The following agencies, interest groups, and individuals were consulted during the feas'ibi 1 ity study for the Scammon Bay hydroelectric project: U.S. Fish and Wildlife Service; Alaska Department of Fish and Game; Alaska Power Authority: Public Health Service; Bureau of Indian Affairs; Nothern Technical Services (NORTEC); AVEC: Homer Hunter, Mayor of Scammon Bay; and residents of Scammon Bay. RELATIONSHIP TO ENVIRONMENTAL REQUIREMENTS This document was prepared under the guidelines of the National Environmental Policy Act established by the Counsel on Environmental Quality. The document is in full compliance with Federal and State of Alaska regulations, with the exception of the Coastal Zone Management Act which will be met upon completion of the final document review. Although the Scammon Bay area does not have an approved Coastal Management Plan, this project, as stated, is consistent with the overall Alaska Coastal Management Plan. The U.S. Fish and Wildlife Service provided a Coordination Act Report as per the Fish and Wildlife Coordination Act of 1958. A copy of the Coordination Act Report and Corps of Engineers responses is contained in Appendix A. ALTERNATIVES • The Corps of Engineers is authorized to study the feasibility of hydroelectric alternatives and, if warranted, recommend them to Congress for construction authorization. Nonhydroelectric alternatives are also assessed; however, the Corps of Engineers is not involved in their design or construction. 3 Hi nd Generati on Conti nuous \1i nd recordi ngs are avail ab1 e fron Cape Rortanzof, approxinate1y 14 niles \'lest of Scamon Bay on the south side of the Askinuk r10untains. \~ind direction varies, but "lind from the northeast is the most comon. Because of the northeasterly \'Ii nds, Scallll10n Bay may experience a higher Hind reoime than Cape Romanzof due to its geographic location on the north side of the mountain range. Although no wind data have been collected at the village, residents state that they experience high Hinds for long durations, particularly during the Hinter. Before they joined AVEC, \lind generation \"las used by tHO households. Based on the interpretation of Cape Romanzof ''lind data, it appears that there is sufficient wind, of both magnitude and duration, to supply Scannon Ray \'lith a portion of their electrical energy needs during the \-/inter. The feasibility of uind generation during the sumer is questionable because of the lo\'1er average \lind velocities at that time. Existing Conditions (Diesel) Scamon Ray presently derives electrical po\'1er from diesel-fired generation. The system provides year-round dependable power and meets the needs of the comunity. The econonic feasihi1ity of continued diesel use is questionable because of increasing prices and possibly declining availability. The future costs of producing electrical pO"ler fron diesel in rural Alaska nay become prohibitive. Other alternative energy sources include solar, Haste heat recovery, geothema1, coal, peat, tinber, municipal sol id \taste, and tidal. Of these a1tenatives, geothe~a1, coal, peat, and timber are not feasible due to the lack of these resources in the immediate area. Scanmon Ray's location on the north side of the mountains nakes solar energy infeasible for nost of the year. Recoverable waste heat from AVEC's diesel generation could produce 2,090 million Btu's per year. This alternative ",ou1d require the continued use of diesel generation and the design of an adequate transmission system. If diesel generation continues, this alternative may be a viable ener9Y source for space heating. r1unicipa1 solid waste could produce up to 626 ni11ion Rtu's per year and provide 5 percent of the comunity' s present fuel input requi rement. Effecti ve generation from tidal pO\'ler requires a minimum head of approximately 10 feet. Daily tides at the project area are about 6 to 7 feet. Coupled "lith the lack of mininum head and the icing conditions of Scamon Bay, this alternative does not appear to be feasible. Hydroe1~ctric (Selected Alternative) Hydroelectric pOHer ''Iou1d be developed from a spring-fed stream 1 ocated south of the to\'m of Scamon Bay. The stream f10\'/s from approxinate1y elevation 000 to elevation 50, \/here it merges \.,ith the nain channel of the Kun River. A sna11 reservoir would be excavated upstream of a rock-filled gabion dan, \'Ihich \'/ou1d be constructed at elevation fi96 (existing ground), about 3,500 feet from the town proper. A penstock \'Iou1d run from the intake structure of the dam to an aboveground pO\'rerhouse, \'Ihich wou1 d be located across the strean from the village's Bureau of Indian Affairs school. 4 An open channel tail race approximately 50 feet in length ''Iould be ,_ excavated from the powerhouse to the mai n strean channel. Several ''wr alternatives for the installation of the penstock and for the type of pipe are presented here. A dar:l \'/i th a maximum hei ght of 9 feet Houl d be constructed froM standard manufactured gal vani zed steel gabi ons fill ed \'1ith rocks taken from the reservoir excavation and the stream itself. A sackcrete or membrane cut-off \'/all extendi ng to bedrock ''1ould be constructed at the center of the dam. Thi s cut-off ''IOU 1 d extend approximately 9 feet below the existing ground surface; its top \'Iould be flush with the top of the dam at elevation 600. The dan \'1ould extend about 50 feet across the stream gully and ,,/ould include a spilh/ay with a 13.5-foot-long \'1eir, 2 feet 10\'1er than the top of the dar:l. THO alternatives \"ere studied for the installation of the 12-inch-dianeter penstock. For both alternatives, the invert of the penstock at the intake structure is set at elevation 589, 11 feet belo\'1 the top of dan at elevation 600. A sluice gate would be installed to regul ate the flow through the penstock and for emergency operati on. The penstock would run cim'lnstream at an average slope of 13.5 percent. Under the proposed plan, the penstock \\Iould be entirely buried about 2 feet helou the existing grade. A trench ''1ould be excavated and backfilled as required. The penstock would be anchored and supported as required. A steel penstock was found to be more suitable than other materials for installation because it is more durable against natural diaster or vandalisM. The penstock would cross the stream at a location approximately 550 feet downstream of the dam. The penstock would connect to a valve upstream of the turbine. The powerhouse \'1ould be located at elevation 110 and be built on a concrete slab. The finished floor elevation of the slab \'/ould be about 4 feet above the mainstream "later level. Three different sites for the pm.,erhouse were consi dered, but geol ogi cal fi ndi ngs proved that two of the sites \'Iere not suitable due to potential flooding and unsuitable so11 conditions. The equipment \'/ould be hOlJsed in a small 10xll-foot structure. The project pm'fer would be transmitted through the existing local di stri buti on system. One or tHO ,,,ooden pol es may be requi red for the connection. No cleari ng of any vegetation \'1ould be necessary. ENvmotJr1ENTAL SETTING The village of Scanmon Bay is located on the Kun River, approximately 150 niles north\lest of Bethel, Alaska. The areas to the north and east of the village are 10\'11and tundra, \'/hich is typical of the Yukon-Kuskoh/iM Delta, \'Iith nUMerous lakes, slow meandering streans, and little relief. To the west is ScaMMon Bay and the Bering Sea. Inmediately south of the village are the Askinuk t10untains, a small isolated range that is an atypical feature of the delta. 5 B~ginning at Cape Ronanzof on the Bering Sea, the nountains generally run east ilnd \lest, terni nati n9 approxinate1y 35 ni 1 es i n1 and. The mountai n range averages less than 6 niles in width. Several peaks south of the vi11aqe exceed 1,000 feet in elevation. The lowland tundra area supports the vegetative types associated \'Iith ",et t'mdra, prinari1y a sedge and cottongrass r:1at \'lith a fe\" \1I)0dy plants \there the terrace rai ses them above standi ng \'/ater. The Aski nuk r10untains have t\lO distinct vegetative types. r10ist tundra, \"Ihich extends frolil the foothill s throughout the 10\'ler portion of the range, supports uniforn stands of cottongrass tussocks, sedges, and dwarf shrubs. Alpine tundra, found at the higher elevations of the Askinuk 11ountians, supports lo\'l-gro\'ling nats of herbaceous and shrubby plants. Although the nountain range is relatively steep, the vegetative r:1at conhi ned ~"li th peYT.lafrost ho1 ds the Hater to nake the slopes noi st duri ng the nonfrozen season. 11ilbi tats of the project area are predomi nate1y noi st tundra. The only dry areas are rock outcrops and individual boulders. ~~i1dlife resources are mai n1y bi rds and small rodents with only a rare vi sit of 1 arger nama1 s. Because of the 1 ack of she1 ter and year-round food sources, the Hestern Yukon-I~uskok\lin Del ta is almost devoi rI of 1 arge nannal s. r1any species of birrls use the area near the project. Nesting HaterfO\/l and shore hi rds are abundant north of the vill age in the ",et tflndra habi tat. Thev contri bute to the Yukon-Kuskob'/in Oe1 ta IS 1. 5 nillion breeding duc'ks per year and fall migration of about 3 million ducks. The noist and alpine tundra areas south of the village in the Aski nllk r10untai ns support nesti ng and reari n9 habi tats for an abundance of shore birds. Although no actual population estinates Here nade, visual observations indicate that this is a favorable bird-use envi ronnent. /\n acti ve rough-1 egged haHk nest \'/aS located at the top of the nountains directly south of the village. SnottY Ot/ls and long-tailed jaegers a1 so use the area for hunti n9 snall nanmal s and hi rose An unnamed strean originates near the Askinuk rlountain range sUnrlit and is fed by suhsurface f101"/ throughout its 1 ength. The stream has penetrated the pennafrost and forr:Jed a re1 ati ve1y \"li de streaMbed channel. The rise in streanbed elevation is very steep and the strean is nost1y a continuous torrent of cascading \'later. In several places, the strean has cut to bedrock, but A to 10 feet of unconsolidated material i nterni xed \lith houl ders is present at the proposed dansi te and 15 to 20 feet of the sane naterial is present at the pO\'Ierhol.Jse site. The portion of the strean fron its source to near the village has a very stable strean channel, considering the steep slope and resultant high water vel oci ty. No areas of streanbank eros; on are evi dent and the amount of fines observerl in the streanbed appear 10v. . Historically, the strean supported a very snall run of pink sa1non near its nouth t~ere it enpties into the Kun niver. Several small \/aterfa11s, and one over 6 feet, e1ininate any novenent of fish fron the Kun niver in front of the village into the upper section of the unnamed strean. Even if no \/aterfall s were present, the strear.1 velocity is such that suitah1e fish hahitat is generally nonexistant ahove the village. 6 -The pink salnon run no longer exists in the strean and, accord'ing to the Alaska Oepartment of Fish and Game, no salmon now ente~ the Kun River. The portion of the stream from the village to the Kun River is a meandering tidal slough. The 10l"/er end of the stream is used as a protective nooring and beaching area for snall skiffs. The stream is used by the village residents as their drinking \"later source. The Public Health Service established an infiltration gallery, hol di ng tank, and pumphouse for the \i'/ater supply system. The infiltration gallery is located several hundred yards upstream of the tmin and I'loul d be beb/een the dam and pO\"lerhouse si te of the proposed project. The Publ ic Health Service has recomnended a ni ninun flow of 27.8 gallons per minute, which is equivalent to 0.06 cfs. This ,.,ould provide approxinately 200 gallons per day per capita, Ithich is well above the present consuMption of between 50-70 gallons per day per capita. The holding tank stores approxinately 30,000 gallons, which is sufficient to supply the village Hater requirements for 2 days. There is no approved Coastal Zone r1anageMent Pl an for the Scamon Bay area. The Alaska Coastal Policy Councils Standards of the Alaska Coastal 11anagenent Progran (6AA80. 070) establ i shes cri teri a for energy faci li ti es within the coastal zone. The proposed hydroelectric project is consistant \'lith the suitable site deternination outlined by the standards. CULTURAL RESOURCES In earlier tines, the village located at Scammon Ray \'las known by the Eskimo nane "Hariak." The village I-las later renamed after the nearby bay that honors Captain Charles f1. Scamon, "ho served \'lith the Hestern Telegraph Expedition from 1856-1967. The nane Scammon Bay became corll1only applied to the village in 1951 \'then a post office of that nane was estabished. Other names that have been applied to this locality are Kutnillt, rlallagniut, r1ariakmiut, and r1ariak. The name Kutmiut Has first Mentioned by Oall in 1870 for an Eskimo village located 2.7 miles east of the present village (Orth 1967). The people in this area are of the Mageniut subdivision or tribe of Yupik-speaking Eskir:lOS. The r1agemiut numbered around 400 people at the tine of European contact (Osl1al t 1968: 8) and were essenti ally an i nl and oriented people centered between the Yukon and Kuskokl"liM River about 20 miles south of r10untain Village (Os\'lalt 1967:6, Zagoskin 1967:210.) The 11agemiut Here noted for their war-like behavior. This factor, conbinerl \'lith their renote location, neant that the t1ager.!iut "/ere not exposed to intensive European/Al"1erican contact until recent years. Few ethnographic studies have been done on the area so it is difficult to reconstruct aboriginal subsistence patterns. Present day villagers are involved \lith connericial fishing for salmon and herring; it is likely that these I"lere harvested in the past along with inland resources such as cari bOll and HaterfO\,tl. 7 Good archeological sequences have been "/orked out for coastal areas north of Norton Sound and south of Bristol Ray, hut fe\'l studies have been done for the Yukon-Kuskokvin Delta area. The National Register of Historic Places has been consulted and no eligihle properties are in or near the project area. The State Historic Preservation Office advised that no adverse 'inpacts "/oul d he 1 i kely to occur to cultural resources as a resfJl t of thi s project. Hydroelectric (Selected Alternative) Background infor~ation and field investigations performed for the hydroelectric alternative indicate that little fish and wildlife activity occurs '-/ithin the influence of the project area. There are no fishery resources in the unnaned strean uith the possible exception of the area north of the village near the Kun River. A run-of-river project, as the one proposed for Scannon Bay, does not include 'tater storage. All or a portion of the existing streamflo\'l above the proposed diversion structure \'1ould be utilized for pO\'ler generation and the '-later 'tould be returned to the strean above the area of possi bl e fi shery acti vity without changes in "later cheni stry, tenperature, or flO\'/. The stream het\"leen the proposed di versi on structure and pmterhouse woul d lose sone or most of the flo\'l. The porti on of the strean bet\'teen the pov/erhouse and di versi on structure is above several velocity barriers and 'taterfalls that inhibit fish migration. Because of the existing stream velocity in the area, suitable fish habitat is generally absent. The proposed hydroelectric project would have insignificant impacts on usable strean hahitiit and possible fi shery resources. The pl aceJ:1ent of the di versi on structure, penstock alinenent, and tailrace configuration ",ould cause a teJ:1porary increase in suspended sol ids; hO\tever, thi s nay he mi nor and short temed because of the light load of fines and other snall-grained naterial. To assure that the dri nki ng \later standards for the vi 11 age I s 'tater supply are net, construction of the rliversion structure and penstock nay have to occur in stages. Close coordination ''lith the Public Health Service to detenn1ne that acceptable drinking \-/ater can be stored and distributed would be continuous until project cOJ:1pletion. r1i nor di srupti on of nesti ng and reari ng of shorebi rds may occur during project construction if the activity is rluring the summer months. Although nesting densities are high in the ScanJ:1on Bay area, hird utilization in the area of project influence is 10\1. I~aterfowl nesting north of the village, shorehird activity in the noist and alpine tundra, and pasteri ne bi rd nesti ng \'lest of the vill age are far enough reMoved and the J:1agnitude of the proposed action is snall enough so that only minor di srupti ons are expected duri ng constructi on. Ouri ng actual project operation, the disruption to the hird population should be ninimal or nonexistent. r1aJ:1nal activity in the project area is extrenely 10\'1, possihly with the exception of lemmings and voles. The J:1agnitude of the project ,.,ould cause only short-tern ni nor di stlJrbances of mamnal s. 8 -Construction of the reservoir \'Iould require the excavation of approxinately 170 cubic yards (cy) of naterial. The area of excavation ''1ould be \"Iithin the streambed. The najority of this material ,~ould be used for the construction of the dan and an additional 30 cy of rock r.1aterial frolil the surrounding area \"ould be necessary for the conpletion of the structure. There is enough surface rock nateri al close to the proposed di versi on dam so that a quarry site ,~oul d not be requi red. The excavation of the naterial for the reservoir and the collection of surface rock for the conpletion of the dan '-/ould occur in an area of little biological productivity and no impacts on the biological cor.n:lUnity or physical danage to the environment are expected. Penstock al i nenent \loul d occur wi thi n the strean channel in an area not underlain with permafrost. If the buried penstock alternative is constructen, approxinately 3,950 cy of nateri al \'IOU 1 d be excavated. The penstock t/oul d be pl aced in the excavated area and all the materi al ''1oul d be ~ackfilled. This operation "ould cause short-tern adverse impacts to Hater quality; hOHever, the stream should return to preproject conditions shortly after construction. The placement of the pO\,/erhouse is outside the lOO-year flood plain ina sui tabl e foundati on area. Inpacts associ ated ''lith excavation for a lOxll-foot concrete sl ah and pO'terhouse are mi ninal. Interti e with the existing po\'Ier facilities nay require the placement of one wooden pole in an area that has heen disturbed. The greatest ir.lpact of project constructi on coul d be erosi on caused by liIechanized equipnent on the steep slopes. Geological surveys indicate that pemafrost is present on all slopes ''1ithin the project area with the exception of the stream channel and flood plain. Removal of the thin vegetative nat could allO\·f pemafrost to tha\'I, resulting in ground subsi dence and subsequent creation of deep gull ies from erosi on. Danage caused by tracked vehicles operati ng on tundra underl ai n by pemafrost has been well documented. The construction of the diversion structure, penstock al i nenent, and pm·terhouse facil i ti es, and the transportati on of materials \'/Ould require the use of a small-tracked vehicle that could avoid erosion-prone rernafrost areas. Nornally, vehicular movelilent is not recoQmended in strear.1 channels hecause of "later qual ity degradation and its effect on fi shery resources. Ho\'fever, the strealil channel is of sufficient ''1idth to alloh! the operation of a SMall-tracked vehicle with little or no instrean novenent and sti 11 avoi d pennafrost areas. Water qual ity degradati on \loul d he ni nor and no inpacts are expected to the possi bl e fi shery resources at the mouth of the stream. If project construction comences during the lIinter nonths, naterials and equipment could he ferried IIhen the ground is snO\'/ covered \'1i thout di sturbi ng the vegetati ve nat. Pl ans for \linter and sllmer nobilization have been fomulated and are included in Section T.9 of the nain report. 9 W IUD ClENEr.ATIotJ Although the Corps of Engineers has not designed any plans for the \'lind generation alternative, the facility ",ould probably be located tm'fard the top of the r.lOuntain range several niles south of the village. The major impact associated with the construction of wind generation would be erosion. In order to service the \lind pO\'fer facilities and install the pm'/er pol es, a road \'Ioul d probably be requi red. The constructi on of a road or even a IIjeep trai 111 over areas underl ai n \'lith pemafrost \'foul d cause seri ous erosion. Pemafrost 1 imits the rooti ng depths of pl ants, prevents i nfil trati on of \'fater doum'lard through surficial materials, and so increases surface runoff. Surface \'1ater accur:1ul ates in depressi ons where peaty nateri al s fom, creati ng a continuously \'1et environnent conducive to marsh and tundra development. The vegetative blanket insulates the pernafrost layer, increasing its freezing depth. Disruption of the vegetative cover destroys the fragile thernal balance, resulting in tha\'1, subsidence, and erosion. To construct any type of road in the mOllntai ns behi nd Scanr.1on Bay without causing erosion, an insulating gravel pad \'(ould he needed. Even if a road \Ii th thi s type of i nsul ati ng factor \'Iere constructed, erosion along the edges of the road still nay occur. The construction of \,/ind generation facilities anY\'/here but within the village proper \'Iould probably cause irreversible adverse environr.1ental inpacts. 10 ( 1 ( ) EFFECTS OF THE RECOMMENDED PLAN ON RESOURCES OF PRINCIPAL NATIONAL RECOGNITION Types of Resources Ai r qu a 1 ity Areas of particular concern within the Coastal Zone. End angered and threatened species critical habitat Fish and wildlife habitat Floodplains Historic and cultural properties Prime & unique farmland Water quality Wetlands Wild and Scenic Rivers Principal Sources of National Recognition Clean Air Act as ammended Coastal Zone Management Act of 1972, as amended Endangered Species Act of 1973 as amended Fish and Wildlife Coordination Act Executive Order 11,988 Floodplain Management National Historic Preservation Act of 1966 as ammended CEQ memorandum of August 1, 1980. Analysis of Impacts on Prime or Unique Agricultural Lands in Implementing the National Environmental Policy Act Clean Water Act of 1977 Executive Order 11,990, Protection of Wetlands Clean Water Act of 1977 Wild and Scenic Rivers Act as ammended Measurement of Effects ~'iO effect .r~o effect No effect Temporary disruption during construction; no long term losses No effect No effect Not present in planning area Increase in turbidity during construction, no long term impacts anticipated No effect Not present in planning area Relationship to Environmental Requirements Federal Policies Archaeological and Historic Preservation Act Clean Air Act Clean Water Act Coastal Zone Management Act of 1972 Endangered Species Act of 1973 Estuary Protection Act Federal Water Project Recreation Act Fish and Wildlife Coordination Act Land and Water Conservation Fund Act of 1965 Marine Protection. Research and Sanctuaries Act of 1972 National Environmental Policy Act of 1969 National Historic Preservation Act of 1966 River and Harbors Appropriation Action of 1899 Watershed Protection and Flood Prevention Act Water Resource Planning Act of 1966 Wild and Scenic Rivers Act Flood Plain Management E.O. 11988 Protection of Wetlands E.O. 11990 Preferred Alternative Full Compliance Full Compliance Full Compliance Partial Compliance Full Compliance Full Compliance Full Comp 1 i ance Full Compliance Full Compliance Not Applicable Full Compliance Full Compliance Full Compliance Not Applicable Fu 11 Comp 1 i ance Not Applicable Full Compliance Full Compliance 12 State Policies Preferred Alternative Alaska Coastal Management Program Partial Compliance Anadromous Fish Protection Permit Full Compliance Required Federal Entitlements None Required. Note: The compliance categories used in this table were assigned based on the following definitions: a. Full compliance --all requirements of the policy and related regulations have been met. b. Partial compliance some requirements of the policy and related regulations remain to be met. c. Noncompliance --none of the requirements of the policy and related regulations have been met. 13 APPENDIX A United States Department of the Interior IN I1Ft'1 Y IlrfHI HJ r;.) 1 011<'1 Lct' R. Nunn District Engineer A 1 ;1 s b Iii s t rj c t Corps or i'~ngin('ers Anchoragp, ,\ Laska 99510 I'ISH AND WILDLIFE SERVICE 1011 F. TUDOR RD, ANt'l1( )RA(iI:. ALASKA 1)1)501 (IX)?) 27fdXOO 1 9 DEC i'JfD AU;)clieri is the riml1 Coordination Act (CA) Report which was prepared in accordance with the Fish and Wildlife Coordination Act (48 Stat. 401, as amE'ndl'd; 1f) lISC 661 et seq.). The report provides an analysis of biological information to be used by the Corps of Engineers (CE) in planning and constructing it small hydroelectric project at Scammon Bay, Alaska. The u.s. Fish and Wildlife Service (FWS) began participating in the project in April 1980. Till' n'IH)rt was pre'pared to s;1tisfy requirements specified in the Scope of Work f"r the Small I!y(lropower, Scammon Bay project. Information provided is h;]~,L'd on field inv:'stigation, a literature review, and coordination with [l,·rsonnel from the Alaska Department of Fish and Game, the CE, the Alaska Power I\dmini~tr;1tion. and National Marine Fisheries Service. Should Y(lU have ailY questions, please contact our Western Alaska Ecological Servin's office. Sincerely, ~~".//;){~ . -/1- ,.--~ ~ --~ l .~". , 7 /,' .,. -,I l\.<;oIRtant Area Director l"C: A()I',S, WAI':S }\DFf..C, NHFS, Anl~C, OeM, Juneau III)!-'&<:, N~1FS, AI)f~C, EPA, Anchorage -- Scammon Bay Small Hydropower Scammon Bay, Alaska Final Coordination Act Report Submitted to Alaska District U.S. Army Corps of Engineers Anchorage, Alaska Pn~par,·d by: Paul Hanna, M.L. Nation Approved by: Robert G. Bowker, Field Supervisor Wcst0rn Alaska Ecological Services Field Office U.S. Fish and Wildlife Service Anchorage, Alaska November 1980 -..... -. Table of Contents Page TlltrC)(luct.i()n •••••••••••••••••••••••••••••••••••••••••••••••• 1 Project .Description ............••........•.•.•.......•..•.•. 1 rh·sc t"; rt ion or l{esollrceR ...........•...••...•...•........... 5 Physical Inventory •••••••••• Binlogic;l1 I.nventory ••••••• Scammon Ray Vicinity. Project Vicinity •• 5 6 6 . ... 10 Ma.jnr Potential Tmpacts ••••••••••••••••••••••••••••••••••••• 14 IJi sCl,ssion ...................................••.............. 15 Rc comme nda t ions .....••........••.•...•••••.•••.•.•.•••••..•• 17 IJit("rl.ltllre Ci.ted •••••••••••••••••••••••••••••••••••••••••••• 18 Ar>pend ices ••.•.•••••.•.••••••••••••••••••••••••••••••••••••• 19 - - List of Figures Page Flgure 1. Location ,~nd Vicinity Map ••.••••••••••••.•••••••••• 2 I,'igure 2. Project L~atures in relation to Scammon Bay ........ 3 I'Lgll n' 3. I)nPl. and upper penstock ............................... 4 Figurl> 4. Powerhouse and tailrace ... iloilo. iloilo •••••••••••••••••••• 6 Fi gil T(' 5. View of Scamnmn Bay in relation to the unnamed stream running through the village ••••••••••••••••• ll Figure n. Typical cross-section of the unnamed stream n0ar the lower end of the project area ••••••••••••• ll Figure 7. One of several velocity chutes preventing fish from ascending the unnamed stream •••••••••••••••••• 13 Figure 8. Erosion from the thawing of permafrost in the mountains behind Scammon Bay caused by moving heavy equipment across the tundra ••••••••••••••••• 13 Appendix T. List of Appendices Sci.entific names of vegetation, birds, Mammals, fish, and marine invertebrates Page appparin~~ in the text ............•......•..•...• 19 Apppn(l Lx T r. IHros ol:curring in habitats in the vicinity of Scammon Hay, Alaska •••••••••••••••••••••••••• 23 /\1'1"'11\1 ix I [I. ~';P'c'c ies of whales recorded in the Hering Sea •••• 25 -1- INTRO!)UCT ION The village of Scammon Bay is located in western Alaska on the Bering Sea near the confluence of the Kun River with Scammon Bay (Figure 1). The area is remote, lying 140 miles northwest of Bethel. Access is by air- plClne or, seasonally, by boat or snowmachine. The village economy is based primari1y on subsistence hunting and fishing. Currently the village depends on diesel generators for electricity provided by the Alaska Village Electric Cooperative (AVEC). Costs of diesel delivered to !WEC villages during the summer of 1979 reached $2.50 per gallon (U.S. Department of Energy, 1979). This cost of fuel plus service has resl.lted in power costs to individuals in excess of 40¢ per kilowatt hour with additional price increases likely. Local interests contacted the Corps of Engineers (CE) in the spring of 1979 requesting inclusion of Scammon Bay in the CE small hydroelectric investigation program. The purpose of this study by the CE is to in- vestigate the potential of small hydropower (5 megawatts or less) devel- opment for Scammon Bay to reduce the village's dependence on high-priced fuel oil. Since the Alaska Power Administration (APA) had studies sched- uled for Scammmon Bay as part of a hydropower inventory for the AVEC, the CF. asked the APA to look at Scammon Bay's power potential as part of a cooperative activity, According to the APA, Scammon Bay has the best potenti.ql of any of the AVEC villages (U.S. Department of Energy, 1979). On January 8, 1980, the AVEC filed a declaration of intention with the Federal Energy Regulatory Commission to construct and operate a hydro- electric facility on an unnamed stream near the village of Scammon Bay. PROJECT DESCRIPTION Two hydropower project alternatives are being considered by the CEo Basically, both plans involve a small diversion, a penstock of l2-inch pipe, and a powerhouse capable of generating 150 kilowatts of power (Figure 2). An 8-foot-high dam will be constructed from steel gabions filled with rocks from the stream Clnd reservoir excavation. The dam will extend 50 feet across the stre:lm ch:lnnel and will include a spillway with a 10-foot- widE' weir. A rirnp box intake structure at elevation 576 will be covered by a steel grating trClshrack. Reservoir excavation behind the dam will be limited to elevation 598, with 3 to 1 slopes on all sides (Figure 3). TWt) .11ternatives for penstock installation are being examined. Alterna- tive olle involves burying the entire penstock approximately 2 feet below the existing grade. A trench would be excavated and backfilled over the pipe. Alternative two involves partially burying the pipe for about 100 fpet near the dam. and supporting the remainder of the penstock on piles .,,_ above ground, anchoring it as needed. The exposed portion of the penstock '-" wOllld he insuLlted for thermal protection. On both alternatives, the pens tock wi 11 cn,ss the stream approximately 550 feet below the dam. Figure 1. .. () Location and vicinity map. I I I I I KIIII~I PII\j[UrtJelt I ''5~ ~'C"Je' .He.::l~ :;P:km!llt~i .• : Scale OQuinhagak ,,~ .. 2b Q "· -.../ .. ' " .. ., . .~ I , 3 1" 0: 40 miles. c \ \ I' , \ I \ I I , :~ \ "; J " • ." i ." i -j- J ~, 1," ,. Figure 2. Project features in relation to Scanunon Bay. "~I . -l • I ~ • I " 1/ '. '-, 7 , C.atle Hili", I .. ' , I I I I , , I ; , I' ~. . j t :,l~:', ;,n., .: . ,!::., ... , "';' , ~" , " ,I' ' j ,le. I I ; ,I, , ' ' --. .. ~ ...... -. :: : .: . ~ . ~ .... - ... t,· i .. .,' -: ~ :-~ -.--=:-:- -.--.----:. --.~. j , " '--: :--:---._::- -~:;:: :, -:+0£)--;--~r'~ -5- Three options for the type of penstock pipe to be used are being con- sidered: (1) st.<Indard weld steel pipe; (2) spiral weld lockseam pipe; and 0) reinforced plastic mortar pipe. TIle powerhouse will be built on a l2-foot by l2-foot by I-foot concrete siah at an eh'vation of 100 feet (Figure 4). The floor of the slab will be ahout 4 feet above the main stream level. An open channel tailrace 50 feet long will he excavated downstream from the powerhouse; discharge will take place in a riprapped section of the stream channel approximately 50 feet below the powerhouse and 100 feet above the village. An energy 'dissipator cons1sting of additional riprap will be placed in the channel. Project power will be transmitted through the local system. No trans- mission line is required; however, there will be a short tie-in line from the switchyard to the transformer. The project installed capacity will be 150 kw and the tie-in line will be 15 kv. No permanent access roads or maintenance facilities will be required for the project. DESCRIPTION OF aESOURCES Physical Inventory The village of Scammon Bay is located in the Alaskan Bering Shelf physio- graphic province (Wahrhaftig, 1965). The Yukon-Kuskokwim coastal lowland section of this physiographic province is a thaw-lake dotted marsh of which more than a third is water surface. Nearly all the coastal areas are in lowland tundra. The lowland tundra is a vast treeless plain, covered with intermittent stands of brush, blind sloughs, and bogs. Uniformity of the delta is broken by an intri- cate pattern of meandering streams and abandoned cut-offs, interconnected sloughs, and countless lakes indicative of a low gradient and poor drainage overlaying permafrost. Elevations as high as 10 to 15 feet above sea level are unusual. The Askinuk Mountains, a small isolated range, lie immediately south of Scammon Bay and are an obvious exception to the relatively flat lowland tundr<l of the Yukon-Kuskokwim Delta. Beginning at Cape Romanzof on the Bering Sea, the mountains generally run east and west, terminating approxi- mate 1)' 3') rni les inland. TIle mountains are relatively narrow, averaging less that 6 miles wide. Several peaks s6uth of the village rise to over 1,000 feet in elevation. Scammon Bay's climate is more maritime than continental. Winters are eold and often windy along the coast. Summers are cool, with onshore wincis,fog, or overcast skies causing even lower temperatures much of the seasoll. Daily maximum summer temperatures are usually below 70° F and of tell below 60° F. Temperatures rarely reach the extreme lows and highs encollntl'rpd in the Interior. Annual precipitation rarely exceeds 15 inches, but because of frozen soils and the flatness of the tundra, runoff is slow. Open water occurs from breakup in early June to free7.c-lIp in early October. Northeasterly storms blowing off the Bering SC;l occur ,Ill year. , . r .: \ J : : i I ,1 . ! ; ~ . ~ . ; t' :{ , i ,I i; . i ' I ; ! if / i -'.':' /! \ \ ; J f !;' ; ;; '\' ; , f i ','.;' I ': i \.: J / ,;. t ;! ! !" ; \ } i ~ . : " .. ;:-. iCfOG!:l~-..L r-{""'/C I " = ~DDI -7- Recent CE suhsurface investigations established that the project is sited on soils composed of unsorted sand and gravel. Excavation pits on the stre'am banks yielded glacial drift mixed with glacial-fluvial gravels. Approximately 25 percent of the drift contained boulders larger than 1.0 foot in diameter; the remainder of the glacial-fluvial deposits consisted of fine to coarse gravel and cobbles with some sand. Permafrost was net encountered in excavation pits dug at the three possible powerhouse siter. and at the penstock site (elevation 600 feet). It was estahlished that a permafrost thaw bulb exists beneath the spring-fed stream; however, permafrost is present everywhere on the slopes adjacent to the stream channel. Biological Inventory Scammon Bay Vicinity Biological resources near Scammon Bay are representative of species associated with coastal lowland tundra of the Yukon-Kuskokwim Delta and alpine tundra in the Askinuk Mountains. Scientific names of vegetation, birds, mammals, fish, and marine invertebrates discussed are listed in Appendix 1. Vegetation in t 11e vicinity of Scammon Bay is characteristic of the coastal lowland tundra associated with the Yukon-Kuskokwim Delta. Viereck and Lit tle (1972) classify this lowland vegetation type as wet tundra. Many shallow lakes, little topographic relief, standing water, and permafrost close to the surface are characteristics of wet tundra. Microrelief is provided by peat ridges and polygonal features related to frost action and ice wedges. Vegetation is primarily a sedge and cottongrass mat, usually not formed into tussocks. A few woody plants (willow and alder) occur on the driest sites where the microrelief raises them above the standing water table. There are no trees. The prf~sence of the Askinuk Mountains immediately south of Scammon Bay adds two additional tundra vegetation types normally not associated with the coastal lowlands of the Yukon-Kuskokwim Delta -moist tundra and <11pine tundra (Viereck and Little, 1972). Moist tundra occupies the foothills and lower elevations of the Askinuk Mountains. This vegetative type vClries from almost continuous and uniformly developed cottongrass tussocks with sparse growth of other sedges and dwarf shrubs to stands where tllssocks are scarce and dwarf shrubs tend to dominate. Alpine ttJndra occupies the higher elevations, ridges, and peaks of the Askinuk ~1()1lI1t.1ins. Much of this type consists of barren rocks and rubble inter- sperseo with low growing mats of herbaceous and shrubby plants. Dominant plilIlts ill this type are low mats of mountain avens which may cover entire ridr,es and slopes along with many mat fonning herbs, such as moss campion, black oxytrope, arctic sandwort, and several grasses and sedges. The most important wildlife resource of the Yukon-Kuskokwim Delta in the vicinity of Scammon Ray is the avifauna utilizing the coastal lowlands. -The tremendous array of lakes, streams, tidal flats, and bars interspersed .~ with tundra and sedge flats make the delta one of North America's outstand- ing w,lterfowl and shorebird areas. Approximately 2.8 million acres of tlw western Yukon-Kuskokwim Delta south of Scammon Bay is administered by ----------------------------"'-~-.. --.. -.. ---.-.. - -8- till' FHS CIS th(· C1arp nc(' Rhode National Wildlife Refuge. Future additions Wfll/ ttl enr.ompass the entire delta in the proposed Yukon Natiunal Wildlife Rl' fug!'. Nt ne ty-s ix speci.es of birds (Appendix II) have been documented on tltp r.larenc(' Rhod£' refuge and most likely represent the avifauna of th(' project vicini.ty. However, the extent to which waterfowl, shorebird, ;/11.1 P'/;;··'I'rill(, ;;p('ci('s IItilizc habitats near Scammon Bay is not well (',\"1111)('11 t,·ll. Aquatic hahit;]tn of the western portion of the delta are generally less fl'rt-ill' than more productive wetlands farther inland (Alaska Department of 1'1:;11 and Came (ADF&G), 1973). Annual aquatic heat budgets are lower, r('slllting in gellcrally lower productivity. However, lower fertility and productivity arc offset somewhat by a greater number of lakes per square tnt h' in thf' wt'st!'n~ delta. Shallow and partially drained lake basins and narrow COClstcll. fringes of tideland similar to habitats near Scammon Bay appear to he tile most productive. 'TIlC' Yukon-Kuskokwim Delta is the largest of the western tundra waterfowl h;dd tflts in Alaska (ADF&G, 1973). Some of the highest breeding goose dens iUes in the world are found on the outer fringes of the delta. Most of the black brant and emperor geese, and nearly all of the cackling Canadn geese and white-fronted geese in North America breed on the delta (ADF&(;, 1971). Tidal habitats on the Clarence Rhode refuge support densities of over 200 black brant' and geese per square mile. Most of the whistling swans in the Pacific Flyway breed on the delta also. The ADF&G (1973) estimates an average of 1.5 million breeding ducks use the delta which provides a fall flight of about 3 million birds. The most common species are: greater scaup, pintail, oldsquaw, American wigeon, green-winged teal, black scoter, and common, spectacled, and Steller's eiders. Shon'hirds, also common in the rq;ion, include bar-tailed godwit, semi- palmated plover, American golden plover, common snipe, whimbrel, bristle- thiglH'd curlew, spotted. least, semipalmated, and western sandpipers, gn'11 tel" and lesser ye llot\1legs, dunlin, long-billed dowitcher, sandhill cr;tne. loons, "nd grenes. Thl' i\f)F&C (197 l1a) i nclicates that the most common raptors on the delta are t\rl' n,)l/gh-lq~ged hClWk, gyrfalcon, and snowy owl. Sowls et. al. (1978) lravl' <incllnlf'nt('d only one seabird colony along the shores of Scammon Bay. At CdPl' r~()Pl<lnzof. i-I few cormorants and horned puffins nest in the cliffs. I'ela,dc connorards ilud tufted puffins are also probably present. Glaucous, 1\1('1.', ;llld Sabine's gulls, and arctic terns are abundant on the coastal 100.,olal1d tundra; they nest as solitary pairs or in small colonies of up to r)o p;1i rs or lIl()rC'. l't·w big gamc' mammals occur near Scammon Bay. Although the delta is a rich hahitilt fnr bied::;, it is not preferred habitat for most large tl'l-n'striaJ sppcjes (ADF&G, 1973). A year-round food supply and adequate s1t('ltl'l aT<.' Iwt ilv.1jlahle. Trees are absent on the delta aud willow and ;lIdl'rs an' sparse ne;lr the coast. According to the ADF&G (1973), moose, hr<l\"Il/)~ri7.7. Ly hhlr. wol f. wolverine, and lynx are rarely seen on the -9- western portion of the delta. Harren ground caribou were present through- out the delta in the mid-1800's. By the late 1870's, the herd had appar- ently shifted to new ranges and essentially disappeared from the area by 18g,). Caribou have not returned to the delta since that time (ADF&G, 1973). Small mammals present on the delta include: arctic fox, red fox, marten, mink, river otter, short-tailed weasel, beaver, muskrat, porcupine, snowshoe hare, arctic hare, red squirrel, and arctic ground squirrel (ADF&G, 1978a; Jonrowe, 1979). Beaver are abundant in the delta and are expanding into areas of the tundra that appear to be marginal habitat (Jonrowe, 1979). Arctic fox are presently abundant along the coastal fringe, but red fox tend to inhabit the area about 60 to 100 miles inland from the coast (Jonrowe, 1979). High densities of muskrat, mink, and weasel generally occur in the coastal lowlands (ADF&G, 1978a). Arctic hares occur along a 60-mile band on the coast and are locally abundant wherever willow and alder patches are present (Jonrowe, 1979). Populations of marten, porcupine, snowshoe hare, ced squirrel, and arctic ground squirrel either do not occur or occur only occasionally in the lowland tundra near the coast (ADF&G, 1978a; Jonrmve, 1979). Other small game species on the delta include: rock ptarmigan, willow ptarmigan, spruce grouse, and ruffed grouse (ADF&G, 1978a; Jonrowe, 1979). Willow ptarmigan are distributed throughout the delta wherever suitable brush patches exist. Rock ptarmigan are found near Scammon Bay in the Askinuk Mountains. Spruce grouse and ruffed grouse are normally not found in wet tundra habitats similiar to those near Scammon Bay. Marine mammal abundance is not well documented for the coastal area near Scammon Bay. According to the ADF&G (1973), polar bear, 7 species of pinnipeds, and 16 species of whales (Appendix III) have been recorded in the Bering Sea bordering Scammon Bay. Sea ice conditions and the result- ing distribution of marine ~~mmals along the western coast during any given year depend upon a variety of factors, including weather, winds, and water currents. In some years, the sea ice pack extends south far enough to bring polar bear; bearded, harbor, ribbon, and ringed seals; and walrus close to the shores of the Yukon-Kuskokwim Delta during the ,,,inter ;lnd early spring months. No hauling grounds or rookeries for walrus or seals have been documented by the ADF&G (1973) in or near SC;llllfTlOl1 Bay. ThL' occurrence of whales off the coast of the Scammon Bay area is also depl'lldcnt upon tIl(> seasonal advance and retreat of sea ice. Beluga and minke whales are prohably the most common whales close to shore as they frequently feed in nearshore bays and inlets. All five species of Pacific salmon are indigenous to the Scammon Bay vid ni ty. Chum salmon are the mos t abundant. Chinook salmon rank second in abundance, followed in order by coho, pink, and sockeye salmon. Pink and sockeye salmon are present in limited numbers only. The Kun River enters Scammon Iby approximately 0.25 miles north of the village of -10- ~;c;]mmon Ilay. According to the ADF&G (l978b), no salmon enter the Kun River. Till' hlllk of Ul(~ sellmon found in the marine waters off Scammon Bay ;Ire' headinr'. for the Yukon River draillage (ADF&G, 1978b). I'aci f i_c TH [ring, ;~s well a!; several species of smelt, including capelin, <-ln' prl'~;ent in the Scammon Bay area also. The ADF&G (l978b) indicates tha t Pacif ic herring spawn along the flOUth shore of Scammon Bay and are the Dilly fish species in the area utilized by commericial fishermen. :;cvt'r;l1 shellfish species, including king crab, tanner crab, and several species of shrimp, are present in the marine waters; however, these shellfish resollcces are limited in ahundance and not currently exploited (AOF&G, 1978b). The abundance of these shellfish species in the Bering SC':J ClrC'a north of latitude 60° N is low (ADF&G, 1978b). According to the ADF&C (1978c), the following fish species are present in t1w Kiln Riv(~r <lnd fresh waters of the delta near Scammon Bay: northern pike, burho t, Dolly Varden, and several species of whitefish. Residents of coastal villages where large concentrations of salmon are not common, sllch <l!, Scammon Bay, rely more he<lvily on the aforementioned species or trilvel to other areas to eatch salmon. The presence of lhreatened or endangered wildlife species near Scammon Hay is not well documented. Eight species of whales listed as endangered by the U. S. lJepartment of the Interior (1979) occur in the Bering Sea. These 8 species are: sperm, bowhead, gray, sei, fin, hump-backed, right, and hlue whales. The extent of the distribution or relative abundance of t1wse endangered species in or close to Scammon Bay is unknown. TIle peregrine falcon is included in the list of birds occurring on the Clarence Rhode Uational Wildlife Refuge as an occassional migrant (Appendix 11). Three subspecies of the peregrine falcon are found in Alaska - Allleriean, Clrcti-::, and Peale's. Both the American and arctic subspecies are listed as endangered by the U.s. Department of the Interior (1979). 'I1w American peregrine falcon br('eds along the lower Yukon and Kuskokwim JUvcrs. l1owever, the fla t lowland coastal areas are not preferred nesting hahiLlt and no evidence exists that the American peregrine is found near Scnmmon B(lY. Based on limi ted da ta, the western coast of Alaska has no historv of h.1vi,lg supported more than widely scattered pairs of peregrines (Fyre ct. a1., 1976). The cliffs at Cape Romanzof may offer potential IlC~;t ing h:d)i LIt hl!t data are lacking. \o/ide separation of relatively i imi tt'd bn'l'di ng sites along the western coast may account for apparent sporadic nesting (Fyf!' Pt. a1., 1976). A FllIall sprill),,-fed, unnamed stream originates in the Askinuk Mountains tli ]-l'Ct 1 Y sOllth of Scammon Hay. This stream flows through the village and pre'spntly serves as a SLlurce of domestic water (Figure 5). Water from a pill!' hurieci in the stream is collected in a storage tank and then distributed to 10c:11 residl'T1ces. The stream is very clear and biologists visually ('S t i Hid u'd it was f lowi ng less than 10 cubic feet per second (cfs) during r LvI" i.nvestigations on July 12 and 13, 1980. The rise in streambed (·Il'vatlollis very steep and the stream for the most part is a continuous torrent of Cilsciidinr. water (Figure 5). Several small waterfalls, and one ,)V('r (, feet (Iiigllrc' O. eliminate any movement of fish from the Kun River in front (If the village into the upper section of the unnamed stream. -. " -_r.. --- I • Fi~lIr£' • View or SC,'1l1l110n Iby in n-lation to the unnamed sLrC';}lll running throu)!,h llw villn)!,C'. Photo by Paul Hanna. Figlll"e . Typi,";l1 (O"oss-section (,f til£' lInrwm('d c;tream near till' lowI'r PIHI of the project ,1rca. Photo by Paul Hanna. The portioJJ ld til,-' sln'am thilt flows through Scammon Bay rLlpidly loses ('\f"J;lt ion :lnd prior to f'nt('ring the Kiln River becomes a meanJering tidal slough. The I{)wl'r pod of the str.eam is used as a protective mooring and fH';l(:h i ng ;I n':1 rl)r silla 11 skiffs. According to one local resident, the strcnJ1l m;l'd to Lave il pink salmon run but it has disappeared; this is prnb:lb1y .1 H'stdt of overfishing. Th<lt port ion of the stream from its source in the Askinuk Mountains to tilt' vicinity of the village has a very stable stream channel in spite of tIll' steep ,c;lope apd resultant high water velocity (Figure 7). No areas of str":1rnbank f~rosion were evident, and the amount of fines observed in the streambed appear to he very low. II;lh i. tats of the project area are predominately moist tundra. Even though th(' mOllntillns behind Scammon Ray are quite steep, the tundra is soggy and spongy und.'r[oot. The only dry areas are rock outcrops and individual h0\11ders sticking out of the ground. Regardless of the wet conditions closlJ to the surface, the tight absorbent mat of sedges, mosses, lichens, grilSSf'S, anel low ShPlhs prevents rapid overland flow of surface water. Pl<mt species identified in the project area were: Labrador tea, crow- berry, h!'arherry, roseroot, horsetail, shooting star, bunchberry, louse- wort, moss c~mrion, violet, and wild celery. lvi lell i Fe' n'SOllrces of thf.~ project arca are predominately birds and small rodents. The variety ilnd abundance of the avian resources of the Scammon Bay area arc impressive. Although the density of nesting birds per square milc' is unknown, it mllst be very high. The interspersion of mountainous terrain, coastal lowlands, and American green alder thickets provides habitat for a great variety of birds within a very short distance of tIl(' vi] Lrtge. Shorehi rds were abundant in the moist tundra and alpine tundra habitats hell ind S,.~amm()n Ba~1. Although onl y a few nests and juvenile birds were St'I'TI, most of the adult ~.;h()rebirds displayed nesting behavior. The shorehirds inclllded lO's of we~>tern sandpipers, least sandpipers, dun- lins, and rock sandpipers, and a few American golden plovers. Passerine hirds wen' scarce in the moist and alpine tundra habitats. Several 1<1;l]il11d ] OTl}',Spurs, snow buntings, and one water pipit were observed. Ten S,IIJ,Jll ill ('ram's wert' feeding at the I,OOO-foot-level. Approximately five Pdl"<lsi t Ie .iaegcrs were hunting the area at all times. A snowy owl was ;)1;.;0 Il\JS(:I-verl perched on a small knoll. A rough-legged hawk nest was h1und a f tlw tOT' of the ridge behind the village at 1,100 feeto The IJ;l\vk's IH'S t, cs tah 1i3hed on the ledge of a large rock about 12-15 feet fro1n ground If'vel on the lee side from the prevailing winds, was 2 feet in ciiamctl'f, shallow, and constructed mainly of sticks. The nest was '1n;)ccuric'd, but numerous fur balls, primary feathers, and down were below tilt' nest indicating recent use. lmlned iil tf'l Y Wl'st of the project area at the 100-foot-level are extensive til ickL'ts of Amprican green alder. Passerine birds were very numerous. AI I of" the follOwing species observed were abundant and many juveniles V'('(' pn'st'nt -lapland lOO,f;::;pHr, common redpoll, white-crowned sparrow, y" I low \v!l)'. r d i l, 1-/i1:c ;t)n' S \vd rb Ie r, ye llow wa rb ler, savannah sparrow, 1',r;lv-clJ('l'ked tllrllsh, cHId golden-crowned sparrow. ,.-., -13- Figurp . One of several velocity chul'es pl"evpnting fish from ascending the-unnamcd stTcam. Photo hy Paul lIanna. Figllre En)~,ion from the thawing of permafrost caused by moving hp:lvy eqllipment across the tundra in the mountains Iwld nd Scamillon Bay. Photo hy Paul Hanna. -14- ~lHrsh ann pond areas ot the wet tundra habitat characteristic of the lowlands nurth af Scammon Bay support the greatest density and variety of birds of any habit .. t near the village. Biologists surveyed about 10, <teres which consisted mainly of small shallow ponds separated by strips of drier ground. Slwrebirds were the most abundant of the avian species representC'd by lOa's of least sandpipers, 10's of western sandpipers, black turnstones, northern phalaropes, rock sandpipers, and dun1ins, and several long-billed dowitchers. A few waterfowl attempt to nest in the area, but are subjected to continual hunting pressure from the village tC'2nage hoys. Green-winged teal were the most abundant duck, with fewer white-winged scoters, scaup, mallards, and pintai1s occurring. One pair l)f whis tl ing swans was nesting across the Kun River from the village and three sandhill cranes were seen flying overhead. Other birds included 10's of glaucous gulls, arctic loons, tree swallows, bank swallows, and savannah sparrows, and lesser numbers of glaucous-winged gulls, herring gulls, mew gulls, arctic terns, parasitic jaegers, common snipe, and lap land longspurs. Tllnnels, burrows, and runways made by lemmings and voles were the only evidence of mammals present in the project area. Two species of lemmings and two species cf voles are most likely found in moist and alpine tundra habitats near Scammon Ray. These species are: collared lemming, brown ler.lming, northern red-backed vole, and tundra vole. There are no fish in the stream above the village. ~le to the stream velocity, suitable fish habitat is generally absent. Several velocity chutes prevent fiEh species present in the Kun River and adjacent tidal sloughs from ascending the unnamed stream behind the village (Figure 7). The lower porticn of the st.ream eventually loses elevation and meanders through a narrow band of wet tundra and tidal flats before entering the Kun River. Ni' •. rOK PIWJI'CT I.MPACTS Potential adverse iml1acts on fi-.'1 and wildlife resources associated with a small. hydro project on the stream running through Scammon Bay should be insignificant. The greatest impact of the project could be erosion cilused by r~:echanized equipment moving on the steep slopes. Removal of tht' thin protective vegetative layer could allow permafrost to thaw, IL'sult.tnp, in ground subsidence and subsequent creation of deep gullies fn-'m erosion. A minor amount of moist tundra habitat available to nesting birds and I'I'den 1.1 \.; J 1] be lost from excavating rock and soil for a diversion, positioning the penstock, and installing a powerhouse. Birds nesting in the immed ia tc pl"oximity of any of the project features will be disturbed JlIr-Ing cDnstruction of the presence of human activity and mechanized (~qllipment. Any short-term loss in production from these impacts would be imperct~p tib Ie in cOJ:lparison with the total number of birds and rodents \Jsing [:;01 st t'll1dra habitats near Scammon Bay. There <1rp no fish in the stream above the village and none of the project Fe;l tures :-;houi d ~1aV,~ [lny impact on the lower portion of the drainage or tllL' Kun Ri.ver. Like\orise. there are no waterfowl nesting in the foothills - -J.J- immediately behind the village. None of the-project features should have any effect on the wet tundra of the coastal lowlands where most of the waterfowl nesting occurs. Due to the stpep terrain and the inherent problems associated with moving heavy equipment on the tundra, erosion is a definite hazard. Evidence of "cat" tracks can easily be seen on the slopes behind town very close to the project ares. In several places near the top of the mountain, severe erosion from the thawing of permafrost has created gullies 3 to 4 feet deep (Figure 8). Because both penstock alternatives involve some excava- tion, there is a possibility of thermal erosion if pockets of discontinuous permafrost are encountered. Since the diversion, penstock, and possibly the powerhouse could all be located above the village's domestic water intake, any erosion could easily enter the water supply unless proper precautions were taken. DISCUSSION The FWS has concluded that few adverse impacts on fish and wildlife resources from the project are anticipated. Those that may occur are judged to be imperceptible provided that methods to minimize erosion are implemented. Erosion from th~ thawing of permafrost has been identified as the major environmental impact. Any construction requiring heavy equipment working on the steep tundra slopes must be done to eliminate or minimize removal of the thin vegetative cover. Figure 7 illustrates the consequences of ignoring the impacts of heavy-tracked equipment on alpine tundra south of Scammon Bay. The widespread occurrence of permafrost in Alaska poses special engineering problems in design, construction, and maintenance of all types of structures and facilities. Permafrost limits the rooting depths of plants, prevents infiltration of water downward through surficial materials, and so increases surface runoff. Surface water accumulates in depressions where peaty materials form, creating a continuously wet environment conducive to marsh and tundra development. The vegetative mat insulates the permafrost layer, increasi~g its freezing depth. Disruption of the vegetative cover destroys the fragile thermal balance, resulting in thaw, subsidence, and erosion. According to the A=ctic Environmental Information and Data Center (1976), there are three engineering approaches to permafrost: 1. Avoid it. In areas where permafrost is discontinuous, location of improvemen~s can be directed to areas free of permafrost. 2. Destroy it. Where permafrost is shallow, it can be thawed by stripping the surface of its vegetative cover. In some areas, soils can be excavated and the area refilled with coarser materials. 3. Preserve it. Structures can be developed on gravel or artificial pads to prevent summer thaw after vegetation is removed. It is also ----------------------------,----,--------- feasible to build structures on piles, thereby preventing thermal heat from fl_owing into the ground and destroying the solid, perma- frost base. Refrigeration units buried in the ground might also be used to maJntain cold ground temperatures. Since the (;E is seill exploring alternatives for the penstock at this time, recommendations concerning minimizing potential impacts from erosion are general and no! necessarily site-specific. Construction of a diversion will require excavating material and will probably necessitate the use of a tracked vehicle with a blade or bucket. Excavation work in or close to the stream capable of adding sediment and turbidity to the watercourse, such as building the diversion, must be coordinated with the appropriate governmental agency responsible for the Scammon Bay water supply system to insure that drinking water is not contaminated. Pecause no access road is avai.lable for transportation of equipment to the diversion, we recommend that the diversion be built after the tundra i11l8 frozen in the fall. Impacts from tracked vehicles on the thin layer of tundra vegetation are considerably less when the ground is frozen. No diversion should be built where there is any chance of exposing permafrost close to the surface. Continual slumping of the streambed will occur if the permafrost melts. Where the diversion is built, some type of protective mat should be placed over the exposed soil to prevent erosion from rain and snowmelt and the area seeded with grass at the beginning of the next growing season. If the CE decides not to construct the diversion when the tundra is frozen, access to the diversion site becomes more of a problem. In many places, the high water stream channel (bank to bank) is wide enough to allow a small "cat" to move up the drainage parallel to the stream avoiding traversing the tundra or negotiating the steep banks adjacent to the stream. Through time, the stream has cut down to bedrock, or close to it, aml left a very stable substrate of rock and small boulders capable of withstanding the weight of a small "cat" without damaging the stream channel or stream banks. Although moving equipment close to a stream 1s not normally re~ommended, in this instance it would be preferable to constructing a "road" on the tundra. For reasons previously stated concerning permafrost, we recommend that the penstock be elevated and not buried. Furthermore, there appear to be adequate room and suitable foundation support in the thaw zone along the stream. Placement of the penstock parallel to the stream will make it unnecessary to lay pipe and foundation supports on the tundra. Penstock pipe arId other equipment c,gpable of being easily transported by helicopter :,hould be flown, to the area and not moved by heavy equipment. If it is necessary to level an area for the powerhouse, we recommend it also be done wlH~n the tundra is frozen, and a thick protective gravel pad be placed ever t~e exposed soil to provide insulation. In all instances, any fuel, oil, or lubricants should be stored and handled in such a manner so as to preclude their entering any watercourse. -17- Under provisions of the Alaska Native Claims Settlement Act (ANCSA), the village of Scammon Bay has selected all lands encompassing the project area. However, conv~yance of those lands has not yet taken place. Once the boundaries cf the proposed Yukon Delta National Wildlife Refuge are established, use of conveyed lands will still be subject to refuge rules and regulations under Section 22(g) of the ANCSA. At this time, the FWS does not foresee any problems associated with a small hydro project in this area on future refuge management or administration. RECOMMENDATIONS " . The following recommendations are provided to minimize the potential environmental impacts of constructing a small hydro project at Scammon Bay: 1. that the use of tracked vehicles to construct the diversion take place when the tundra is frozen; 2. that the movement of tracked vehicles used to construct the diver~ion be restricted to closely paralleling the rocky stream- bed should the diversion be built when the tundra has thawed; 3. that the CE coordinate all activities in or near the stream with the appropriate governmental agency responsible for the Scammon Bay water supply system; 4. that all areas of exposed soil be covered with a protective mat material or other suitable means and seeded with grasses at the beginning of the next growing season to prevent surface erosion; 5. that the penstock be elevated and closely parallel the existing stream channel; 6. that renstock pipe and other equipment easily transported by helicopter be flown to the construction site and not moved by heavy equipment;. 7. that any leveling for the powerhouse site be done when the tundra is frozen, and a thick gravel pad be placed over the exposed area to provide an insulation layer; and 8. that any fuel, oil, or lubricants be stored and handled in such a manner to insure they do not enter any watercourse. ","--"----"----'---------------------------- -1.1 t('rlltllYC' C (ted :\I:1n ":;1 !'I'f:;:rt.;.~t.t (If Flt>h antI C:"~110. 1971. Al~ukn'~ wildlIfe and 1!lnn4n. 143 I'P. and ltuh 1 t :1l. }-:(11 ted by !I,. I.er-eRe-ho tlwi :". S(] ~"'l~' I' L!~; 1:.1 !',c t ,~t n",'I' rt t of rJ.!; h R nd r.am". 197 8a. .Ill .111;'.1J 's ,.,lld Uf e and !,''It:lt. Ve']II.",' TI. (o):p11,'<.\ by I:. ~:11nkl'art. 7 /• PP. llnd 521 flllpa. '\::,'" "ep:IT't 'I·:,t (,r {'Ish nnci (:w('. 1':,7::11>. "1(1;'\:11''; flllhC'rie6 .. nIall, ;),. 1'1 nl') • It:) r;l. "nil 357 V/"h:,',·!. C:" p.Llt·" by 1.. l'e1..,:.'1!". ;:r.1I K. • ,I;:!I".': ;:'T:ll'!: (,·Il!. \,,·1,:, .• ;r. l,;f FIc!, mil' Gnrw. tr'7I'1c. Al'!:;!",l'f', fl~h!'rlca Iltlas • ('(";";Ic~ by p. ~:cl,(1l1l and 1-'.. :'o.:itdll·V. 43 pre and 269 '., .. J i! t: • l!'(,tic l1;\·lrl,:,II""t.":l Infl'rrl~tl(1\l .'1nd r..'lttl CI~!1t~r. 1')7( •• Aio(1ka r" j,"].' 1 1\(;[,:1('5, \'ohnw ITI. ;;()lltIJIH~f>t Pt';'!on. E:11ted by !.ldL~ ",,'lkn':;·c',. J1,\ rp. FvfC', ;) •• ~:. '.lef,;-.le. :to,] T. Cl'ldc. 1976. The 1<)7~ tlorth American I"'rl':r!r"~ f;droll ;':unll:'Y. Ctll111<lhn J71dd-1.1'.turl'll1nt 90(3)2 22(l-213 • .Ior:n),,-(·, j"l. 1~:79. Sllrv<,y-Invcntory progn~tls report. Furb\larers :.Ind I'P":>ll :,t.;:·C. C1ill 1~· -Yll\<on-~:usb,bdll1 Deltll. 1977-78. ttl: .\T'I'IU:ll t't'I'ort of bllrv~y-lnvr.ntory Ilctlvltl~l'I. pllrt II. Yuri;'8areT9, \10If. ~~c·l\it·rlnl'. j,:"I111 ;~DI:'(.~. Fe(\'l lliri .in \/11dllfo I'eotoration. '.'(11.1:-:, !'ro,1. Q-17-1G. Editl'.:! <lnJ c(lnp.l.lct! by r~. Hlnr:1ltn. /,lAo1<a r1.'!WrtLf.'r,t pf r l:il. Clnd Gn:"c, Jl.lflC!I1U. 192 PI'. ::,,'1;]1;, II •• ~" lilitel-,. 'll\~ C. L .. ,!.b!nl:. 1")7:;. (;ltIl10), of ,\lllokan seabIrd (:olnnJ.'r.. ,:1,,1".',1(':' l ;,c!'vicl'tl ['ro;';T .. -1. Ftl"h :In." I:lldllfc" ServIce, l.'.~~. :'('l'drt;C1,t of thl' Ir:tu·lnr. 32 P:'. ;H:J ::'01) ri1pn lind tabl~s. tI.!:. lil.~.lrt; Cl,t r,f ;,1'·('1'/v. 1 )70. ~':',,11 hy(irr.elcctric lnv(~'llory of ~, . ~ .. vJ J L\!~c!1 ~('n'(:(~ by AI;,;:!:;! '.'illa~o t':10<.:t r lc l~o"";lI'riltlv~~. Al;,IR~,n !'o· .. ·'·r .',1" !;~l,'t1":'tf.()n. ,1111'1(",11, i\[,l",',rl. 1:~'1 ;','. ',"ltll t~r"l('nrJI(:efJ. !',·;'>.1rt:,('·q of r!'.,· Int<'Ller. 1')7'!. I t·,t nf" '::l':;,";"!Z"L';' and thl'cut.:tH,d \;/1,:111., :'" 1,l.oIl!" ~~~~E_~~~~_:~~:~.'~ 1",(1;): ill(-'~,.)/, • . \1 n .l:~" t l'J,.,f ~-, ,:.~ hl-· r'I"~. "I'"C1r.O!tt f'e: J V f Ct'. u. ;:. nl"r:tr (I'.t n t ,. f /.:, I Ie ,.d ~ ,l"i.', ,\'~ ric til ttl re "" n" h C).:\: :' I, 1 (. • :' (': i' ~ • ~',.hr!.l:ft ll~. c. lrh~). rl1VI·io,~rnphlc cJivlElnr~ of AJn~ka. Gco1of,lcal : : (. r \' {' Y [. r' !'. i. , ! • (. r !,." ~ • I: • s. C. t' V 't l'r 1 n tIn ~~ II f f J c (: • I; tI B h 1 n ,; ton. !i.C. :).',r.', 1,r,. ,-l.1'Pfi:DIX T. ::clf:ntlfic Ol'lrJes j.lf vCf,',etntlon, hirds, r,:t'rlr..ah, tJ.llh, and lI'dl· Illf· J l\V'~ rt, l. TO" (~n lIP!'I(':1r .1nr, 1 n t h~ t c.'}( t. '': 1 J J O'oJ .~""'r('r lelln (;r(lcn ,\ 1 de. r Cotton Gr.Jse r:C>IHI Carr J 011 ~\ln~\.: O:<ytrnpr Aretlr Sandwort !':O\l:H:~ In AvenM lHbra(Ior ,"l'a CrowhQrr,:, Bf·tJrherry r.., ~ E' rl'tl t Hors"'[1l11 ::hoot Inp, Star !:unchberry LOllt:t-vort Violet \H 1 d Cd f'ry i~ IDck flrllnt !::~r·cror GOOSl! CnckllnE Cnnafa r~D~C p. 1 tl!-frontcc ''';U1lti(' \'hlstllnE f,ll.:ln Crc;.It('r SCUlIP Plnt"l1 (; 1,1!'lI:l1H\1 A;.t'r Ie:;n \.'li:enl) Cr,,'cn-vl n!:t~d T('.'"! 1 "i,1I:1, !ic(I(I'r r:O::I:lon I:ldt.'T ;';1'1'(: t:\C'lcd l:l"I'r !;tt'll('r'!l l~ld( .. r n~r-tdlled CD~vlt ~~l' :,1 t I'll I r,lll t c.-I"! P! C\'(' r :,, :{~r !L;;ql (:.,II't:r, p Ipv,~r (ty:'~'nn ~'nl!H.' I':d!';l'rd I~r lHt 1 ('-thl,~hfd C\IT 1('\,1 ~: i'() t l 1.,,1 ~:'l~ n,'" 1 pe r Lva:1 t ~:ilnclpll't!r ~.p," I i ';1 !: ';1 t ('(1 0':1 rl(! p II' t' T' \;'·',\.\'1'11 SHn(~pll'l..'r i'[vI1I'"t' Y<,,·llf""!.~l'n ~)<; J 1·~ flpr. Ti;;-;r:-.£ r 1 ~\ r a T:: rIC' r; ~, 0 nil' n p p • f,ll(!ne IIc)'111s c")'t rople n 1 £ rNJc.r.ns '11IlIl,1 r t 1!l l\ rc. t Iell Dryns lnt~~rlfolla U!du~ pdu!ltre ,t:L'PC t r1ll~ nl;:;rul!I Arcto8ttlphylotl alp1na ~t:(llIr,1 r08('.1 !':t;u!l'I.ctUl'll "pp. T1odecI1 thean f r ls1<"ar'! Cornua c~na~en81. Pedleulariu spp. nob bLf loru Anse ilea lucid' flrantn t-f!rnlcla Phlla;t~ cnnneicn l~rRntl! clu'!ddf'nsiH !!!!!.~ A1"sr.r nlhlfrons (Hor ('.,llP',:donlls -'-A'~y t hi!:' :.:: r U!l /llhlR nCHt.l 7.Tii"fll jt7in't. 'r PI'! n 11 ~ AnilS lC(!r lr:atl.ll ~ "creCCit ~;n Tt~-;' I~r" ~nnnterld nnll19nl~a Sn-l,H('rla fltlcht"r1 1'0 Lyn t lctllAtellC!rl LJr~o"" Ippron lea (htl r.1l1! r lur. serdrlll"otu8 £ tHV 1.1110 d0r.11nlea C~pcllA gal11n8go ll\l~ ('nlun ph"t'npua !'n~('n Illt: 1:.1"1 tlena1. A~tjt!R ~nC"14r1a Ca)l" rLR 1':11 nut Uta r.d It.rh pl1flllln (1\11111" l!'l r·;'ur.1 ';'rlnl~ :'.It'J!lnolcuc. I l , , 1.f'S8t!r Yo l1ovh'~!1 T:ouollo Lon~-h1l1ed r.owltchcl" ~,lndh 111 Crilo(l :~o\J rh-l~p, ged lID...,\; ( ;',rfll!con !':1l0WY (h,,1 I'I~ J n~'j c Co["t"I()rRT;t P('rncd ('uff In 'iut fe'd Puff In cl:'ucot!s Cull ~'l:I{ Cull :'~iih 1 JI(~' s CuJ 1 /"rrt Ie Tern !'r)ck Ptcn:l;:.l'In I.: 1110\1 Pt,1T:~l :'(111 ;~PT\I(:f~ Cn)IU,l' ~:\ll fc'! CrOUt:\;' t.· ;.'r ':'C;11; I'l'rl'!~r Int· !'£l.icnn !lctlc l'cfl"'rlrH' l',l1r.r.1 r~31r'B rcrc~rln~ ¥nlcon t<,ck ~:;llldplr{'T tllr 1.ll\d LOI~\,t'ipur !:!IOW Pllf:t 11::- !,.':'ter Pipit P;l r ... f.' 1 t. 1 c .. J {l(' .".l!T Cl)r·.r~('tI r.'.'-!.Ijloll \f,ltl.·-crr'\JIIl'C ~parr()\1 y '_~ 1 l,y,.' '.';~,: t;~ 11 I:ll"r:n' ;'.1rbl(!r 'I I.e 11 (.11; .. ! " r b Il' r ~':'v"ltrwh ~~I'lIrro'.l rr;l'l-d~l.'l'l·(~d TllrtJSh i ~·ll.·( 1,-err,I,II'-,! SI.;~rrO\l J'.l.'1ck T',rnr.t'Oll'· ,l)rt ~','~rtl I] .:1 Ij1r'.,~,(· ( : J'( :l t l'r ';":. \1 F 'tl L: rt~ ' .. ,\, I f .~-\J1l1j',hj ';(;,)t("r 'j' (' t [c 1./10\1 ':1" l' ':'.,11,1(1': 1 • : ~ \ I •. I !, 'I ' ,; 1.,.('('11:;-\.'[ lI:ed Gll] 1 I r t,,,: ':11 J I F T()\m ler i z :': 1 Y :',(:11 T 1'0 I ( lif·lvcrlne !.."IIX 1.:, .• rr<'l1 C['oulid CArlLou /(ctlc Fo:; F,('d l'ox Trlne:'! flovlp~1I Cal1rlrh Iliplna (,1 "mod romuf!. .co lopaceu. Gr"", cftnOI!t\tHI1. ~CI la8(\£ua ~'JJ lee) rue t leo 1 til' ?:yctcn IICl'Indlftc:l Phal"croc0r~x £r.LftflcUO Fru.t(~rctll" (',nrnlcnlllta tund" elrrhftta La rlts hyp.' rhorpu9 r.~rll~ Coiln1l!! ::P", ,1 "ill;;T ~t~rn~ pRrndlsBc4 L"'Gl~ T'!\J ttlft Lrti(OPUS l~;"opu~ C[Jnllchlt!!~< cat1l1rlcmlls ;~ Oll>,:;'\ II r .:)f~ t 1m; T~r~~R Bn,ltlJ~l i'tllr.o rerl'er 1 n~ tundr lUM "'£lleo l~t:nTrlnus Eealel Gallrlr18 rtiin~ncnl~ C"lcarlus I11pponlcufJ ~c:tr(lplH~nllx nlvalla Anth\18 IIplTwletta StC!TC:I)r:lr1.uH pllrtllllticuo (;,rduel!!> fJAD11"'oCU };nl1ot r lchln lcu~'ophrYR "otHc.l1le flava ~: 11 ~(ln ill 11;11;111 a lj(~n(!r_~ rr.tcchl11 ra;.: ~:t' r(.;l! lllil Allndttlchcnals; ._--.. - Catl .. 1TlI!1 ·-Lnl::-.t!!'I ~~1·1.;i :i.tr lCllP lll.l I\f"I:-, r L'':'' _ ~::..L1nN~~ i"llll;ln)[)~"~ Job:!!'!!1 ~'~~~I~Jln --.-,~--A;j:·,~·, pl.:.t ·.'~.·!ri'ncl!og -----------"'-'-,--: 'e L~ ,,[ t f "'t·:· Irq·,a ---_ .. _-. --. (::1.,.):': 'rrf If'/t lrLl,,,Jrp(':' I'Le"lor ----, .. _--_.,--,_ .. 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HoJ\.,'hcHO h'llale Crny 1.111.l1c ~e J ~!l-'1I1 t" FIn I!half' ElH"p-I;B('k(~i.1 ',:tUl J e !:ll.ht \·,1wl<:' !', I ue 111\.11 (~ i'rn; (!;.,rt !:.'ll~',()n ell In();~i. ~;n 1',11,'11 :'L11: :;"lncn "ockl'),c S~\ll~ol\ )':1(:1f11' !!l~r'Cltl": err'l·tio ':l'r PI(' rn r lI~t~ 11.1 'H;i::I h 1 :l C k f 1 ~ h \'~I ltd 1sh r'll r 1, fl t r'("l) 1 y ":ln1~n :lar tr.n "rwrlcana l'!ur. te· 18 y 1 !'Ion "Lut Cli cnnndenols ; '1\9 t (\ J 11 C' rnJ nOA Cuptor CAnn~cn~J8 r~c':1 t rn z11,(' t h lcu. r. n: l " 1 t.c n ell, r ~l\tUtl 1.(':)'16 a:"'criC':wIls L~T'"5 II rc t L ('.tJ~ T:tt" i:, -'!r.1.L: n :1; 'It1C,~On lclJS !~~lpf\ ~.I i.'~: r..L\rryll ~~.:~ tor(1llatu9 I.f)I\"I!>; ~; II; I r iellt! Cldl,rl.)n,:...l.L!. rutllus :~lcr(\t\l~' 1,(COnO:"lU8 UrSUH .. lilt J t lraus T'r !l!rl8thm. barbatu8 I'hncll vltul1no Phoca fltlfchta }hoc.:1 h hi' Idts Odobc,nus rosnarua fJel,rhln.;lpterul lQUCt18 DnlnennptcrH acutorootratB Physetet cnto(lotl f\" lsl<'nn E'L~J tlcotua l:fl('hr J cli f, f II~ rohuGtll1) !!:ll.'lelloptPfl'l borenl,b i',;p 1 M'nn!, t" t"n £hvn nlu!l l!eL:1p t(.'r:t nnVaNlnG liac, :\;lj.~ .L~.!.!!!. f\ it! :w r. r,p t '.'!.:!. .:.~: C II h "I ::cl":ltltI.' ; "-," C:r}(:(~Y"~ ·.'~:t·· .. t!.: ~~('t "~ __ p---.i, __ ., ___ ._ -r!C'(lr:.Yl:cl·lII: !~lS11td\ (:l\c\.lrhvncl ,\IS ,~orburichil Cn(:f1rhync!lur. ncrlw r; Illp~:~ .P.t! t 1/\ 1;1 1. ~:ill lntns \,UIOOIl8 I:"ox Il!cl~'!R !lalllH ~:torIlJJ" COl·C!f.0ntl~l 9pp. 1.0 t II lot 11 ~(.~:; l:lall'lll !: 1111' r:r,J!, T;m!'!er Cr.ilh SclentH Ie ~ra"Q ------- £'111'.1 1 I tilodt,'l cnr·tsch.tlc.a Chjunoec("t(·s spp. ,- ......... API'r.~",n: TT. Inl,~ occurrlnr In !1:,hltllt ... in r.h~ viclnity (of Scaamon r.l1Y. Alaska. ::TATUf,' Co:' : "ie"' 11 Lnt' n . u n -:~------Y til (:I'-b J 11 ('(. rJ'OI~ r r. llrc: tIc too.... 0 n r,:.:-tl,ro ... l\d Loedl ----1!C'n~l.·(1 Cr&.~bc -------r:"<!-!';I·C.t~t'f' Crl'·l...~ -----'7!:IbtJJIJF, ~V;III --,------C;~l:I·ll',;' C.'In,";,,' (; .• nne 'r,'I\'('('\'('r' :" c.·[".,~ .. 1 <:00(:1) I', .L ,: d~ l' r L~] t ---.•.. -----I'i"r'l~ ("or \ :e,()!;.' c- u U II :1 C C d :1hl'f .. -fn''1tld CO()"~, A r.('t;~l'r ~:!1(i' l:l~()b<" n :',dJilTd 1I r./,dlmll r i'in t.d 1 R t, i 'j r I (' In I I,ll (. ('ll n c ... _ .. _- ')f~rt!:,'rn ~:hn\'('l('r II C;,liv~I;I!Hd' u Cl'c;,~"r r';'WI' 8 Lf'~~~a'r :~C':JlJ? u ,\; ~t'[ I( ill! Gpll,:l"h!yt~ u ----!I'.ll'riol,'fl Coldl'n(!y',' " ----1~,!rfl,'!'C'Olri II OJ('~(~lliIH 1I !:, r 1 ,: ~i 111-;:;--r !',ll' ll(,r' ti~7~ u 1:,I['nn rl':('r n KJ.,.,;.~ ,Cider c ~',;) .. c. tile 1" r! " l (I ,', r --- n 1\ n n n n n n n n n " n M JI rl n m C'l n n J1 m n n \:'1, 1 t ,~-\ .. t n ;:',e:1 ~'r. ()' \' r _____ u r: !c',! r f :'. (' \J t (, r II TO ._------ :1 J , .. ;i· "('(I t. r (: r1 __ , _____ .4 __ _ (-(OJ' U"I ~~t·l:·:;n~·rr ___ ,_ •. _ r 1 l" ~ -1. t' c. I d b t ( . d , , r ;' ,:"1 II n •. r 1\ If )', r: \' t" f .. d (" ( 'n " r ;,' 1 ", r 1 n \. -j:;31~~--'----() . ----_. ('(~':"l! i,(·:troll C 1"(0: :,(1;' " .. ,Vff'! -.. -----U ---_._-- :: I .. d-c;'p["·,! Ch 1('1 !I,"'l' U n n 1'C r. n n \'1 ." ,\ r I Com :.dd!"l t) n ----- STATUS C-ft n U 11' it n u c a ?uc1dy Tunhltol\t C ~bck Tllrn;Jtnne n ----Co~~on ~nlpc c ~111r.,hr<: l -u nrlf1t Ip-·ti~ ll:.hN' CurleW' u !;l'ott,,~ S,lnrlplpf'r r c.;relltcr \'cl10l/1r::tI u Lp,q'er Y,'lln'.:lC'[',tl ____ U t.l!U5t Siuldpiper u tun 11" :--:~~~:--__ a l,('n~:--hTfI'e'7-i" !'oul tchpr c :;(,,'l~td;·,E1t(~d Sallliplp£r_ u iJ':f'tr.:rn ~;'Hld:>lpcr ____ D r,nr-t:ll1,'(\ Corlwlt II ---~ ;ll1(k: r I llH, ________ 0 J~t"d Pto.;~lnrorH' c -----~:ort'wtl\ P",:darope ___ u I'n: ',lI r j rH,' .1" l';:(' r 11 r~rdtlilic Jn~~er c Lt)f',':-t.,1. 1 ('d .r,'\,':·~·r Il ~;li\I\C('ll'; i:!I1. J n (;, oUC:tl1! :;-'.: lr~:~\'(! ld: 11 It !krril," ~,lIl1 0 • '[,\1 ell L 1 a n n n n n n m Itl n n n n n n to n n til n D n n n n ~/.·;hln(~"; (:::11 n n tI n --- rl'ort-l';lTf",1 ',M 1 V jn 1(! t-i'. n''':~ .. ,:,ill i.M Tr('C' ;'\/,1110'.,1 110 rn ::\f{\ Ito'" u n ll-C n C 11 U n c n u r: 1.1 f f ::;.o:111(l'.1 ___ u n n n n :)'lV~nn:lh :;:)orn! • .' __ II Trcn fr~rr~' n \,1dt~-cro\.~wd ::p:I['rml u n r.olc!en-crotmed ::p:lrrov-u n Fox fr~rrcw - c n f.3plnnt! l.nnt:~l'lIr a n ~:oary '~('dpoll_ u 0 wAh'r Uplt u n C J" in ~ f c '-(.' l'" 0\,':1. 't-~ ~:nTh.lf!r u n "ct.:'\y·s nuntinr c. In 'l"'l) n'.' ;'Brh h·t" u n SnO'.1 Runtinp, c n -._------,-- .';,'un:l:; C!HTcncf' Y·:hodf! l::.ticnnl \Hldl1fe l\eflJ~:e. l~ethelt Alatlka. c (:llr;r':'on II -tlllC()r";' •• )n (l ,.cent'd non 1 r n r.1 Tarn OT ocelrlcntal nestlnt: .dl'r<lnt (! .(~. non-:1··Slinr. Du~er rcn!dcntn) It rCRldl'nt nll 'It:.:lHn\'"l~' -~PI'Et!!nX rlI. ~FCclcti ..,r \1hlll~R r('corcied in the flering ~ ••• ;·,f·lu·'11 \l~~ d J (' flltc:,. ',!1;r)(' ;1,\ rbor \'(1 rpr..l '<t' ;:Pt.t'. J'·-1U)!)I.'(! I, t:J~](,­ '·tf:.j·H.r:;,!r'~ l.'l';'!·(!" \,~l;l!(' ~'I~l):.,·-~ f·.1~ t.'e! :.:~I~' I ... ,'-;d 1 ;·~;r·I,,:)l·:l·' t .~ i r·o.,ll! ;1 1 1',(I\.'I!I'lld I'IHJl(> ere; ',/h,de ;r-l \In.:ll,,· 'I n:'C \:h,., Ie j'ln ';Jh;! I.' ;' l'l f .! 1 "lie DISTRICT RESPONSES TO FISH AND WILDLIFE'S COORDINATION ACT REPORT RECOMMENDATIONS 1. That the use of tracked vehicles to construct the diversion take place when the tun~ra is frozen; Response: The use of tracked vehicles will occur only when the tundra is frozen or along the streambed where permafrost does not occur and the erosion potential is low. 2. that the movement of tracked vehicles used to construct the diversion be restricted to closely paralleling the rocky streambed should the diversion be built when the tundra has thawed; Response: Refer to number 1. 3. that the CE coordinate all activities in or near the stream with the appropriate governmental agency responsible for the Scammon Bay water supply system; Response: The Alaska District will continue close coordination with the PubllC Health Service and any instream work will be accomplished to minimize impacts on drinking water quality. 4. that all areas of exposed soil be covered with a protective mat material or other suitable means and seeded with grasses at the beginning of the next growing season to prevent surface erosion; Response: The construction should not impact the protective vegetative mat as it is designed. If any areas are disturbed, adequate measures to prevent erosion will be implemented. 5. that the penstock be elevated and closely parallel the existing stream channel; Response: The proposed penstock alignment will closely parallel the existing streambed, however, it will be buried. The buried scheme was selected because it would be less suscept'ib1e to vandalism, snow creep, freezing, and stream activity. The proposed alignment is not in an area of permafrost and erosion should not occur. 6. that penstock pipe and other equipment easily transported by helicopter be flown to the construction site and not moved by heavy equipment; Response: Due to the size of the project, there will be no equipment classified as "heavy equipment". The penstock pipe and other construction materials will be moved either by helicopter or land vehicle during the frozen ground period, with little materials moved up the streambed during the summer months. 7. that any leveling for the powerhouse site be done when the tundra is frozen, and a thick gravel pad be placed over the exposed area to provide an insulation layer; and Response: The area for the proposed powerhouse is not in a permafrost area. 8. that any fuel, oil, or lubricants be stored and handled in such a manner to insure they do not enter any watercourse. Response: This will be included in the stipulations to the cont ractor. APPENDIX B ( ) l'nited State~ Department uf the Interior ALASr~ FIELD OPERATIO~S CENTER P.O. BOY. SSO J.~",,;. _ Ar 991\02 D16~rict Engineer . Alaska District, Corps of Engineers P.O. Box 7002 A~ch~rage, AX 99510 DEar 51 r: -:-ne draft interilt feasibility report and draft environmental assess- ment for Scammon Bay, Small Hydropower Study, Alaska (ER 81/2598), was re- viewed at the Bureau of Mines, Alaska Field Operations Center. 'The stream that will furnish power is one of sel/eral small streams that drain the Asklnuk Mountains, a prominent east-west trending ridge of undifferentiated granitic rocks riSing from the coastal plains. This ridge has no potential for oil or coal deposits. It was not considered favorab1e for gold placers and, consequently, it is not known to have been prospected for .etallic mineral deposits eitber recently or in historic times. If ecouoaic mineral deposits do exist, tbe relatively small devel- opment proposed would have no adverse impact. cc: Director, Division of Field Operations BOK, WasbiQgton, D C Sincerely, () Comment noted. '~.;,~\. , I, • \ DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 5~AnL£ R~"IONAc OFFICE ,j i II' , ' .... ARCADE nAZA BUILDING. 1321 SECOND AVENUE SEAnLE. WASO;INGTON 88101 ·10r. l. Colonel Lee R. Munn District Engineer Corps of Engineers Alaska District January 4, 1982 P.o. Box 7002 Anchorage, Alaska 99510 Dear Colonel Munn: Subject: Scammon Bay Small Hydropower Study iCC We have reviewed your Small Hydropower Study and Environmental Assessment submitted with your December 2, 1981 letter. There are some HUD funded projects in the area that are noted in the review conducted by our Anchorage Area Office. Their comments are attached. We concur with your finding of no significant neqative environmental impacts and find no objec- tion to the proposed project. Thank you for the opportunity to comment. Administrator cc: John Duffy, BUD Anchorage Area Office AREA OFFICES (.,.) Port ...... 0,...,.. , Se.,.Io, W .... I .... on • Anchor .... Alask. Comment Noted. See following page. TC FkOY SUDJECT: ( ') Robert C. Scalia, Re~iona1 Director CPD US DlPAI?TMlST OF HC't:~IV; A\'P UR[L~\, [l[\,[LUI'MEST December 31, 1981 I" REPLY IlEFER TO. I CJ. I S5 "e ... t.on Chase, Environmental Clearance Officer Scammon Bay Small Hydropower Study & Environmental Assessment Our office has reviewed the above-named study and ha5 had the foUm.-ing comments to make: w (I) Population data used evidently derives from the 1980 Pr~l1minary Cen- cus. The final Census shows one less person. (2) AAO currently has plans to build 39 ne ... housing units in the village in 1982. These are 24 new units and 15 Bartlett replacements. Only 24 units are indicated in the forecast on Page 16. (3) (4) AAO also has agreed to fund a Recreational Facility/Gymnasium, ($160,000.00) in the community. This project is listed only as a cur- rent need. 'AD agrees that this project should have no significant negative im- pact. However, it should be noted that failure of the dam at the proposed location could present a threat to residents down stream particularly to proposed HUD housing sites. Please note that AAO is currently in receipt of an Alaska Native CDBG Pre-application for 6 -2kw wind generators proposed by AVCP. Mevtoo Chase Enviraa.ental Clearance Officer PREVIOUS EDITIO" IS oa50L~TE HUO-96 (1-75) () 1. Com~ent incorporated into Final Report. 2. Comment noted. The text and the energy demand forcast have been revised to include the additional housing units and the recreational facility. 3. Due to the small size of the dam, its inherent stability, and the location of the reservoir, a dam failure would not present any significant danger to downstream people or structures, with the exception of two culverts where the Public Health Service water supply lines cross the stream. These culverts are often filled with rocks and as a result are not capable of paSSing high flows. This was evidenced by erosion caused by high spring runoff that was noted above the culverts during the Corps' field trips. 4. Comment noted. We believe that wind should be pursued to supplement energy needs; however, we understand that funding -.y not be available for these units. ER 81-2598 United States Department of the Interior BUREAU OF LANO MANAGEMENT Alaska State Office 701 C Street, Box 13 Anchorage, Alaska 99513 U.S. Army Corps of Engineers Alaska District Engineer P.O. Sox 7002 Anchorage, Alaska 99510 Dear Sir: •••• ~'I' aa'p 1'0 1790 (911) JAN 11 1982 We have reViewed the draft copy of "Small Hydropower Study and Environmental Statement for Scammon Bay, Alaska" (ER 81-2598) and have no commenL Please consider this a negative reply in accordance with the Code of Federal Re- gu1ations CFR 40 Part 1503.2 in that the document is satisfactory in regards to 8LH jurisdictions and interests. () S~l~~ .. .:;~~~ Chi:t?'Ca":nin:::? Environ- mental Coordination Staff corrment noted. ( ') United States Department of the Interior IN REPLY REFER TO, Lee R. Nunn FISH AND WILDLIFE SERVICE 1011 E. TliDOR RD. ANCHORAGE. ALASt.:A 99503 (907) 276-3800 11 JAN ~2 District Engineer, Alaska District Corps of Engineers P.O. Box 7002 Anchorage, AK. 99510 Dear Colonel Nunn; The U. s. nsh and Wildlife Service has reviewed the Scammon Ray Small Hydropower Study and Environmental Aasess~ent. We have no co~ents to offer. Thank yOu for the opportunity to revievand comment on this document. cc: REO DEC OEPR WAfS Sincerely, () COIIIIIent Noted United States Department of the Interior NATIONAL PARK SERVICE III "'PLY un .. TO: L76l9(ARo-P) Alaska A.u Office 540 We .. 'Fifth A .. ea~ Iloom 102 ADchoraae. Alaska 99501 Colonel Lee R. Nunn. District Engineer Department of the Army Alaska District Corps of Engineers P.O. Box 7002 Anchorage, Alaska 99510 Dear Colonel NUDD: 18 JAN 1982 We have reViewed the draft Interim Feaaibi1ity Report and draft EnVironmental Assessment for the Sc:aDIIIOn Bay Small Hydropower Study and have the following cODments •. Cultural resources appear not to have been appropriately considered. Federal agencies are responsible for affirmative action to identify properties that are on or eligible for listing on the National Register of Hiatoric Places. The atatement in Section 2.2.4 that there are aD known National Register--eligible aites in the project area and the opinion of the State Historic Preservation Officer in. the""Finding of Ro Significant Impacta" that DO adverse impact on Rational legister- eli a i b1e sites would be likely. are baaed on the absence of information rather than the demonstrated absence of aites required by Federal reautations. Although recreation resource impacts are not addressed by the document. there appear to be none. ' Thank you for the opportunity to comment. Sincerely, ~"~ ..-t"' ", I ( ~O-..-'-" Reaioaal Director Alaska Region cc: I I( l~~ _ baional Environmental Officer. Alaska WASO-1l5 The Issue of agenCies not pursuing further cultural 'resources studies after reviewing an opinion of no probable Impacts from the State HistoriC Preservation Office was discussed and resolved at an interagency meeting held after this particular environmental assessment was completed. The Corps realizes It must affirmatively pursue action to Identify and assess significant cultural properties and will perform field surveys when baCkground studies indicate they are warranted. In this case. it was determined that a field survey was unnecessary because major project impacts are confined to an area within the stream banks and ground disturbance will be _Inlmal. 80th factors Indicate a very low potential for impact to cultural resources. A professional archeologist. who visited the project area In the summer of 1981, performed a visual Inspection and gave the opinion that It was unlikely any significant cultural resources would be found at that location (Martland, personal communication). () Department Of Energy "'.;,,~f,(ll r·~ .. t:'f AdmlnlSlJlItlOn PO br .• :,0 junE~U .·~·.B 99802 Colonei lee Hunn District Engineer Alaska Oi strict Corps of Engineers P.O. Box 7002 Anchorage. AK 99510 Dear Colonel Nunn: January 19. 1982 ~:~ il::,;:-~cciate the opportunity to rf'vie~ the draft Small Hydropower Sturly and Environmental Assessment for Scammon Bay transmitted by your December 2 letter. The plan appears to be a workable one that will provide hydropower to the CQr.1l\uni ty. The hydro site at ScaJTll10n Bay was first examined by APA in 1979 during our inventory study of small hydro potentials near villages served by AVEC. During this field review it became readily apparent that innova- tive, scaled-down, minimal-level design and construction approaches to ~ development were the only viable means for justifying s~ll hydros such as this. Even though the assessment indicates feasibility. it seems to us that a simpler design philosophy would result in reduced construction costs. a less complex installation to operate and maintain. and still provide Scammon Bay with a project that would provide many years of benefits. Specific items we suggest might be considered are: Diversion Structure 1. Si~lified design of headworks and elimination of concrete cut-off and drain system. A sheetpile upstream face (with gabions downstream). crest overflow spillway. and slide gates on penstock .and bypass outlet (with hand-cleared trashrack). should Significantly reduce costs. Pipeline 2. Elevate on ti~rs or small freeze piles. with concrete thrust blocks. Possibly use pre-or post-insulated pipe if heat balance indicates. Possibly located on east slope to avoid snow creep. () 1. Due to the limited amount of flow available it is necessary to provide seepage cut-off to assure adequate water for turbine operation. This would require that the sheetpile be impervious. Also, due to the cobbles and boulders in the damsite area, sheetpile could not be driven. The area would have to be excavated, sheetpile would have to be placed and the area would have t~ be backf~lled. which would reduce cost savings.' Also, with a sheetp~l~ face, lce pressure ma~ be a problem causing bending of the sheetplllng a~d valve stems. Wlth no French drains or buried outlet, freezing of the diverslon pipe could become a problem, and the length of time the plant could be operated would probably decrease due to elimination of low flows and greater susceptibility to ice blockage. . 2. An above ground insulated penstock was considered at Scammon Bay; however. the cost of insulation made the above ground alternative Significantly more expensive than the proposed plan. 2 powerp'ant 3. Prepackaged belt-driven powerplant. Genera' ~. All construction accomplished by backhoe with loader ana vibrating or lmpact head. Backhoe would remain for project maintenance. ~e would be glad to discuss specific ideas if you wish. co () Sincerely. /2/ {t~L/r~ Robert J. Cross Admi n is tra tor 3. A prepaCkaged belt-driven generator is an option. See Section T.6.2. 4. A backhoe at the project would be aesirable for basin sediment removal at the dam. minor ice breakup. and other project malntenance. () lo-n,LH ( ) July 9, 1980 Re: 1130-2-1 Harlan E. Moore, Chief Engineering Div. Corps of Engineers Box 7002 Anchorage, Alaska 99510 DIVISION OF PARKS Subject: Scammon Bay Hydro Proposal Dear MI'. l·loore: JAY S. HAMMOND, GOVERNOR 619 Warehouse Dr .. Suite 210 Anchorage, Alaska 99501 274-4676 We have reviewed the subject proposal and would like to offer the following comments: STATE HISTORIC PRESERVATION OFFICER No probable impacts. we request that the project & contact us inmediately. STATE PARK PLANNING No probable or significant impact on existing, proposed or potential state park or other public recreation values. LWCF No cOlDlllent. ip Dennerlein Director CD:mb () Corrrnent notell. IIr t /lAMIIDIID. fOre .. " IlT.'~IEXT OF ~ATljll"L IU:SCU;UCES DlVfSlON OF" /.AM) Alii) WATER MANAGEfoIENT J!'~ (.~ ... p--,~~ ,,-. ..... " .. _., ,9f,7 I 1'.1.,§.1 January 19, 1982 Lee R. Nunn. Colonel District Engineer Department of the ArrI1Y Alaska District, Corps of Engineers P.O. Box 7002 Anchorage. Alaska 99510 Dear Hr. Nlmn: The ~ll Hydropower Study and Environmental Assessment, Scammon Bay, Alaska has been reviewed. The following comments are offered. 1. Since it is known that high winds of long duration are common during the winter months. this energy source Should be more seriously considered. It would seem to nicely complement sunmer hydroelectric generation. 2. Hydroelectric ...-o a. No stream name or location of the proposed project is given. b. It is reconaended that proponents of projects using water. file and Application for a Water Right with this division. This wfll ensure current unallocated water is available for the project in the future. c. It is stated that 551 of the annual energy output from the proposed project is estimated to be usable in 1983. Based on estimated future energy needs. when is 100% of the annual energy output from the proposed project to be usable? This can not be determined f~ Figure 3.1 •. since it is assumed this gives total annual demand. whereas the proposed hydroelectric project is for sUlllll!r generation only. d. Page 27 gives the benefit: cost ratio as 1.16 to 1. This is considered IIilrgina1. It would appear. therefore. that further studies are warranted to refine the estimates of both the benefits and costs before this can be considered a viable project. () 1. The Corps recommends that wind be pursued in more detail by the State or locals. The Corps does not have authority to design or construct wind systems. 2. liydroe 1 ectri c a. The stream does not have a name. The location is shown on Plate 1 • b. We will advise the ultimate owner of the project to file for an application for Water Right with your Division. c. This figure has been revised to 56 percent in 1984 which is now the estimated power-on-line date. Based on the estimated load growth in the report a maximum of 84 percent of the energy could be used in 1999. This was assumed to remain constant for the rest of the project life. This figure could be higher if a use for the excess energy could be found. such as hot water heating. etc. However. due to load uncertainties we prefer to remain conservat ive. d. Based on the information available the project is justified. We intend to install a streamgage at the damsite to monitor year around flows to determine if winter operation is justified. This would also eliminate the present requirement for periodic streamflow observations taken in town and correlating observed flows to flows at the dams1te. Any add;tional study exoenditures beyond streamgag1ng would not be cost effective due to the small size of the project. The chosen unit has been sized to handle the widest range of flows and energy demand consistent with economic efficiency and feasibility. (J ...... ...... ( ) ~ee ". Nunn -2-January 19, 1982 t. lhe projected power generation from tne proposed hydroelectr,c project 15 base~ on one year of streamflow measurements that. according to page 36. were taker. during a very atypical yea·r for tne area. Although details of the procedure are not eKplained, it appears ~s though this data was modified to represent! typical year.by using nearby rainfall and temperature data for a typical year. Since the validity of this procedure is qaestionable. the resulting estimate of'discharg~ in this stream during an average year must alse be questionable. or at best, very rough. Hence, the estimates of power production and the benefit: cost ratio must also be considered questionable, or at best, very rough. This reinforces the statement in item 2d above. f. According to 11AAC 93.160 and 11 AAC 93.165, an Application to·Construct or Modify a Dam must be submitted to this office prior to constructing a dam that (1) has. a height from the streambed at the downstream end of the dam to the dam crest of 10 feet or more, or (2) stores 50 acre-feet or more of water. Since only the dam height from bedrock to crest is given, it can not be determined if a permi t ; s requi red. Sincerely, J.W. SEDWICK Director BY: ( ) e. .e concur that the available information is limitea and we are continUIng our streamflo. measurements. we believe that we hdve chosen a unit that will operate over tne expected ranges. lntergravel flow in tne 8 to 10 feet of ove~burden at the dams~te was not ta~en Into account when estimating aval~able flow due to.lts unknown quantity. By providing the prop~sed cutoff, we wl11 be able to ut,llze the additional flow. The additional streamflow data being obtained will be considered before plans and specifications are pre;Jared. f. The dam would be less than 10 feet from the downstream end of the dam to the dam crest and it would impound about 1/10 acre-foot. ~~~~~ @~ ~~~~~~ .... a •• 'I1lB SOVBIIN •• DMSIOH OF POlICY DEVELOPMENT AHO PlANNING GOVERNMENTAL COORDINATION UN" Colonel Nunn U.S. Department of the Army Corps of Engineers P.O. 80x 7002 Anchorage. Alaska 99510 January 19. 1982 Subject: SCAMMON BAY SMALL HYDROPOWER STUDY EA-FONSI Dear Mr. Nunn: I'OIICH AW./fIII$, DI6S.1.. JUNEAU. ALASKA 9911" I'HONE: (!J(J7/4~ The Alaska State Clearinghouse (SCH) has completed reyiew of the refer- eced study. ~ The following comment was receiYed from the Alaska Power Authority: N 1. ·We have reviewed the aboye referenced study which was transmitted to us with your 'letter of December 15. 1981. We are in the process of reviewing the project's econoaic viability and of determining whether or not to provide funding for the Corps of Engineers to proceed with final design of the 5-.11 hydroelectric project at Sca~n Bay. A decision will be made on this matter during January. 1982. ·If a deciSion is made to proceed with final project design. State funding may be forthco~ing for construction and subsequent State ownership. operation and maintenance of the project.· The Department of Environmental Conservation (DEC) commented: 2. ·Scammon Bay Small Hydropower Study I Environmental Assessment: Based on avatlable investigations it would appear that the proposed Sca-.on Bay Hydroelectric facility will pose no significant environ- ment~l problell. The s~reamfl~ and gradient in the Yicinity of the proposed ~droelectric structure is suc~ that it does not provide a habitat for fish and wtldltfe. The only impacts which may occur as a consequence of the project relate to the COlll1lUnl ty water supply and air qual1ty in the community. The structure as proposed is above the Publtc Health Serylce water supply intake and any impacts' on water quality could effect the potable water supply. although no nega- tiYe effects are anticipated. Air quality may Improve somewhat due to the planned reduction in diesel generation. () 1. See Comment dated 1 February from the Alaska Power Authority. 2. Text has been expanded to Include additional potential i~acts on Sc~1 8ay's water svstea and plans to eliminate or less .. these I.,acts. Refer to page 6 of the Enyi ronmenta 1 Assessment. () • Colonel Nunn -2 January 19, 1982 3. "A Water Quality Certification under Section 401 of the Clean Water Act will be required before FERC licenses and Department of the Army Permits are issued for this project. Please contact the Department's Southcentral Regional Office, 437 "E" Street, Suite 200, Anchorage, Alaska 99501 for assistance with permits." 4. The SCH has no objection to this study provided State agency regulations regarding licenses and permits are adhered to. We would appreciate being kept advised of any further activity or studies relating to this project. Thank you for your cooperation with the review process. cc: Dan Wilkerson, DEC Robert A. Mohn, APA Sincerely, ;)4.t~/J,;lkf Dave Haas State-Federal Assistance Coordinator () 3 •. The unnamed stream at Scal1lJ1on Bay has a mean yearly flow of less than 5 cubIC feet per second and falls under the nationwide permit under Section 404 of the Clean Water Act. Through coordination witn the Alaska Department of Environmental Conservation, when a 404 (b) permit is not required by the Department of the Army, Water Qua Ii ty' Cert ificat ion under Section 401 of tne Clean Water Act is also not required. The Corps of Engineers is not required to obtain a FERC license for hydroelectric projects. 4. Conment Noted. ..... u. s. EN V I RON MEN TAL PRO TE C TI 0 NAG ENe Y :m:~ MIS 443 Colonel lee R. Nunn District Engineer REGION X 1200 SIXTH AVENUE SEATUE, WASHINGTON 98101 Alaska District, Corps of Engineers P. O. Box 7002 Anchorage, Alaska 99510 SUBJECT: Draft Report on the Small Hydropower Study and Environmental Assessment for Scammon Bay, Alaska Dear Colonel Nunn: Thank you for sending uS the above report. We have no objections to the project and the Finding of No Significant Impacts . ~ We support the proposed close coordination with the Public Health Service to ensure that acceptable drinking water supplies will be maintained. To this end, as recommended in the U.S. Fish and Wildlife Coordination Act Report, any fuel, oil, or lubricants should be stored and handled in such a manner to ensure that they will not enter any water course. We appreciate the opportunity to review this report. If you would like to discuss our comments, please call Dick Thiel, of my staff. He can be reached at (206) 442-1728 or (FTS) 399-1728. Sincerely, b. t.~ea~~tor Environmental Services Division () Corrment noted. () ( ) ALASKA POWER AUTHORITY 334 WEST 5th AVENUE· ANCHORAGE, ALASKA 99501 Colonel Lee R. Hunn U.S. A~ Corps of Engineers P.O. Box 7002 Anchorage. Alaska 99501 Dear Colonel Nunn: May 5. 1982 Phone: (907) 277·7641 (907) 276.()1J()1 We are presently reviewing the feasibility report for the small hydroelectriC project at Scammon Bay. If it is determined to be the best future source of power for the village. as I expect it will. I intend to recommend that the Power Authority seek the necessary design and construction funding for the project. The Alaska Power Authority is aware of the Reagan Administration's proposal that would require up front finanCing by the State. Our participation in the project would be dependent on legislative appropriation. Sincerely. ~.~ p. Eric P. Youl Executive 0 ctor ( ) We will continue to coordinate with you regarding possible financing for the project. APPENDIX C STATEMENT RECIPIENTS Federal Agencies Deputy Assistant. Secretary for the Environment. U.S. Dept. of Commerce Director. Office of Environmental Project Review. U.S. Dept. of Interior Director. Environmental Impact Division. Office of Environmental Programs Federal Energy Administration Office of the Chief bf Engineers. Civil Works Programs Environmental Protection Agency. Washington, D.C. Environmental Protection Agency, Region X Director. Alaska Operations Office. Environmental Protection Agency Director, Alaska Region. National Weather Service Regional Administrator, Department of Housing and Urban Development Commander/Director. U.S. Army CRREL, Hanover, New Hampshire Chief, Alaska Division, U.S. Army CRREL, Fairbanks, Alaska Office of Polar Programs, National Science Foundation National Park Service, Anchorage National Park Service, Juneau Waterways Experiment Station, Environmental Laboratory Director. Western Region, NOAA Soil Conservation Service Study Director, Water Resources Studies, U.S. Dept. of Interior, Anchorage Special Assistant to the Secretary, U.S. Dept. of Interior, Anchorage Area Director, U.S. Fish and Wildlife Service Field Supervisor, WAES, U.S. Fish and Wildlife Service Regional Forester, U.S. Forest Service National Marine Fisheries Service, Anchorage Regional Director, National Marine Fisheries Service, Juneau State Director, Bureau of Land Management Director, Anchorage Field Office, National Ocean Survey National Oceanographic Data Center, Environmental Data Service, NOAA Area Director, Bureau of Indian Affairs U.S.G.S., Waters Resources Division Alaska Resources Library U.S. Department of Energy, Alaska Power Administration Board of Engineers for Rivers and Harbors Advance Council on Historic Preservation Honorable Ted Stevens, United States Senate Honorable Frank Murkowski, United States Senate Honorable Don Young. House of Representatives State Agencies Executive Director, Alaska Power Authority Dept. of Commerce and Economic Development, Div. of Energy and Power Development Dept. of Community and Regional Affairs, Local Government Assistance Div. Dept. of Natural Resources, Southcentral District Director, Division of Land and Water Management Commissioner, Dept. of Natural Resources Director, Division of Communit.Y Planning Commissioner. Department of Community and Regional Affairs Commissioner, Department of Fish and Game, Juneau Department of Fish and Game, Anchorage Director. Division of Policy Development and Planning Coordinator, Office of Coastal Management State-Federal Coordinator, A-95 Clearinghouse Dept. of Environmental Conservation, Southcentral Regional Office Commissioner, Dept. of Environmental Conservation, Juneau COITIlli5sioner, Department of COIIITlerce and Economic Development Dept. of Natural Resources, Division of Parks Dept. of Natural Resources, State Historic Preservation Office Honorable Jay Hammond, Governor Alaska State Library Alaska Historical Library Honorable Vern Hurlbert, Alaska House of Representatives Organizations Executive Secretary, Alaska Conservation Society Anchorage AuduQon Society Trustees for Alaska Director; Institute of Marine Sciences, University of Alaska, FairbalJks Leader, Cooperative Wildlife Research, University of Alaska, Fairbanks Library, University of Alaska, Fairbanks Library, University of Alaska, Anchorage Z.J. Loussac Library Director~ Institute of Water Resources, University of Alaska, Fairbanks Arctic Information and Data Center Director, Nunam Kitlutsisti State Representative, Friends of the Earth Alaska Native Foundation Alaska Center for the Environment Marilyn Sigman, The Wildlife Society General Manager, Alaska Village Electric~l Cooperative Local Monroe Kaganak, Mayor of Scammon Bay