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HomeMy WebLinkAboutFeasibility Study for Old Harbor Hydroelectric Project 1982y Volume C DRAFf REPORT Feasibility Study for OLD HARBOR HYDROELECTRIC PROJECT Submitted by DOWL ENGINEERS ANCHORAGE, ALASKA In Association with TUDOR ENGINEERING COMPANY SAN FRANCISCO, CALIFORNIA DRYDEN & LARUE ANCHORAGE, ALASKA --~-~-.:::--::-::::~::;;--;;;;---· MARCH 1982 Volume C DRAFT REPORT Feasibility Study for R E ( .: I .: D Mftt. (~ l~8iw~ ~IAWA'6Jal'M tzt\J~ijfl}) OLD HARBOR HYDROELECTRIC PROJECT Submitted by DOWL ENGINEERS ANCHORAGE, ALASKA In Association with TUDOR ENGINEERING COMPANY SAN FRANCISCO, CALIFOR NIA DRYDEN & LARUE ANCHORAGE, ALASKA MARCH 1982 ~.....---ALASKA POWER AUTHORITY __ ___. Section FOREWORD OLD HARBOR CONTENTS I. SUMMARY A. B. c. D. E. F. G. H. General Area Description Power Planning Description of Recommended Hydroelectric Project Base Case Plan Economic Analysis Environmental and Social Impacts Conclusions and Recommendations I I. INTRODUCTION UI. A. B. c. D. E. F. G. H. STUDY A. B. c. D. General Purpose Project Area Description Authority Scope of Study Study Participants Report Format Acknowledgments METHODOLOGY General Pre-Reconnaissance Field Study Phase Office Study Phase Phase Nhi-427-9524-tc ii Page v I-1 I-1 I-2 I-3 I-4 I-4 I-5 I-6 II-1 Il-l II-2 II-3 II-4 II-7 II-3 II-8 III-1 III-1 III-1 III-2 IV. '' v • BASIC DATA A. General B. Hydrology c. Geology and Geotechnics D. Surveys and Mapping E. Land Status F. Previous Reports ALTERNATIVES CONSIDERED A. B. c. General Alternative Projects Description and Evaluation VI. RECOMMENDED HYDROELECTRIC PROJECT A. B. c. D. E. F. General Recommended ProJect DescriptioL Turbine-Generator Selection Field Constructibility ProJect Energy Production Project Operation Scheme and Controls VII. PROJECT ENERGY PLANNING A. B. c. D. E. General Projection Considerations Energy Demana Projections Base Case Plan Recommended Project Plan VIII. PROJECT COSTS A. B. c. D. General Cost Estimating Basis Base Case Plan ftecommended Project Costs NBI-427-9524-tc iii IV-1 lV-1 IV-3 IV-6 IV-7 IV-b V-1 V-1 V-2 VI-1 VI-1 VI-4 VI-10 'II-12 VI-13 VII-1 VII-1 VI£-4 V II-8 VII-9 VIII-1 VIII-1 VI II -2 VII l-2 IX. ECONOMIC ANALYSIS A. B. c. 0. E. General Project Analysis Parameters Base Case Economic Analysis Reco~nended Hydroelectric Project Economic Analysis Economic Comparison of Projects X. ENVIRONMENTAL AND SOCIAL EFFECTS A. B. c. General Environmental Effects Socioeconomic Effects XI. PROJECT IMPLEMENTATION A. General B. Project Licenses, Permits and Institutional Considerations c. Project Development Schedule XII. CONCLUSIONS AND RECOMMENDATIONS A. Conclusions B. Recommendations BIBLIOGRAPHY APPENDIX A. B. c. D. E. F. Project Drawings Hydrology Geology and Geotechnics Detailed Cost Estimate Environmental Report Letters and Minutes NBI-427-9524-tc iv IX-1 IX-l IX-3 IX-5 IX-7 X-1 X-2 X-5 XI-1 XI-1 XI-3 XII-1 XII-1 FOREWORD This volume, Volume C, presents the findings and recommendations of a study intended to fully assess the economic, technical, environmental, and social viability of a hydropower project for the village of Old Harbor. Volumes b, D and E present feasibility studies for hydropower projects for the villages of King Cove and Larsen Bay and a reconnaissance study for Togiak, respectively. Volume A is a summary repon: incorporating the findings, conclusions, and recommendations or the other four volumes. NBI-419-9524-FO v A. GENERAL SECTION I SUMMARY Several prior studies of alternative means of supplying Old Harbor with electrical energy had recommended a hydroelectric project as the best source. As a direct result of these prior studies and recommendations, the Alaska Power Authority authorized a feasibility study to investigate in detail the hydropower potential in the vicinity of Old Harbor. This report summarizes the activities conducted for the feasibility study. These activities included projections of energy needs, formulation of a hydroelectric project and an alternative base case to meet the electrical energy needs of Old Harbor, detailed analyses of economic feasibility, and preparation of an environmental assessment of the effects of the project. The results of the study indicate that a 340 kilowatt (kW) hydroelectric project can be constructed at Old Harbor, that the project is considerably more economical than the base case alternative, and that the environmental effects of the project are minor. The total cost of the proposed Old Harbor hydroelectric project is $3,082,300 in January 1982 dollars. The project could be implemented and on-line by January 1, 1985, if a decision to proceed with the project is made by December 1982. During an average water year, the proposed project would be capable of supplying more than 85 percent of the electrical needs and about 11 percent of the space heating needs in the project area. The equivalent savings in diesel fuel in the year 2001 would be about '::J7 ,000 gallons for direct electrical demand and 19,000 gallons for space heating. NBI-419-9524-I I-1 B. AREA DESCRIPTION Old Harbor is a small village located on the southeast coast of Kodiak Island, 50 miles southwest of the city of Kodiak. The selected hydroelectric development site for Old Harbor is located on Midway Creek across Midway Bay from the village. C. POWER PLANNING Power planning for the Old Harbor Project was conducted using standards set forth by the Alaska Power Autnority. Previously recommended potential hydroelectric sites were investigated and the project area was surveyed to evaluate potential new sites. After detailed study, a project was selected and then compared with a base case plan. The base case plan consisted of a continuation of the present diesel generation system, enlarged as necessary to meet future growth. Present energy demands for Old Harbor for direct electrical uses and space heating were estimated and future uses in these same categories were projected. The projections were based on forecasts of increases in the number of customers and increased usage rates. Population growth and employment, legislation and other political influences, life style changes, and other factors can influence future energy demands but they were not explicitly treated. The period of economic evaluation used was 53 years, which starts in January 1982 and extends for the 60-year life of the hydroelectric project after the estimated on-line date of January 1985. The energy demands for Old Harbor were increased for 20 years starting in January 1982 and extending to January 2001. The demands were then held level over the remainder of the economic evaluation period. NBI-419-9524-I I-2 For the proposed hydroelectric projectJ it was assumed that the first priority of use for the energy produced would be for the direct electrical needs of Old Harbor, and any remaining energy would be used for space heating. D. DESCRIPTION OF RECOMMENDED HYDROELECTRIC PROJECT Hydroelectric power plants transform the energy of falling water (head) into electrical energy. Generally, a hydroelec- tric power project consists of a dam to produce the head or to divert stream flows so that they can be passed through a turbine-generator system to produce electric power. In the case of the recommended Old Harbor Hydroelectric Project, a low weir will act as a dam to divert water from Midway Creek through an inlet structure. and into a penstock (conveyance pipe). The penstock will be 24 inches in diameter and will earry the water about 2200 feet to the powerhouse, where it will be passed through the turbine-generator system to produce electric energy. The powerhouse will have the capacity to produce 340 kW of electrical power. A transmission line will be constructed to transmit the power generated at the plant to Old Harbor. Access to the powerhouse facilities will be provided by building a new road from Midway Bay to the facilities and by building a dock at the bay. The dock will be reached by boat j:rom Old Harbor. The transmission line will be constructed from the powerhouse across the upper end of Midway Bay to Old Harbor. The general plan and features of the proposed project are presented on Plates I through VI of Appendix A. Photographs of the project area appear in Exhibits VI-1 through VI-4 at the end of Section VI and in the Environmental ReportJ Appendix E. NBI-419-9524-I I-3 Under the recommended plan, energy generated by the hydro- electric plant will have to be supplemented by diesel genera- tion. The entire existing diesel capacity will be required as standby and backup power. The hydroelectric generation will be adequate to meet the direct electrical needs of Old Harbor during most of the year; however, during periods from the end of November to the first of April it wi 11 be necessary to supplement the hydroelectric generation with diesel power. In all, during an average water year the proposed hydro- electric project will be capable over the project life of supplying an average of more than 90 percent of the electrical needs of Old Har bar and approximately 15 percent of the space heating requirements. Average annual energy production from the hydroelectric plant will be 1.31 million kilowatt-hours (kWh) and the average annual plant factor will be about 44 percent, which means that the plant is expected to generate about 44 percent of tne energy that it could produce if the turbine-generator unit was operated continuously at full capacity. E. BASE CASE PLAN The base case plan formulated to meet the projected energy demands of Old Harbor assumed that the existing diesel system would continue to be used as the sole source of electric power. Because there are no significant heating loads near the plant, it was assumed that the system would not incorporate waste heat recovery that would be used for space heating. The existing diesel plant's capacity was judged to be adequate to meet peak demands on the Old Harbor system throughout the period of study. NBI-419-9524-1 I-4 F. ECONOMIC ANALYSIS The economic analysis was based on the Alaska Power Authority criteria that compare the net present worth of the base case costs to the net present worth of the proposed nydro- electric project costs using specified real price escalation and discount rates. Net present worth is the present value of the costs that would be incurred over a comparable economic evaluation period of 53 years for both projects. The present worth of the total costs of the base case plan is $8,183,000 (rounded). For the proposed hydroelectric project, the present worth of the costs, not considering space heating credits, is $6,397,361. Whe~ this figure is reduced by the. space heating credit of $1,239,000, the final net present worth of the hydroelectric project costs is $5,158,361. A comparison of these net present costs with the base case net present costs indicates that the recommended hydroelectric project is consid- erably more economical than the alternative base case. An additional measure of project feasi bi li ty is the bene- fit/ cost (B/C) ratio. The B/C ratio is the present worth of the project benefits divided by the net present worth of the project costs. For this project, the calculated B/C ratio is 1. 44 when the hydroelectric energy used only for the direct electrical needs of Old Harbor is considered and 1.74 when the nydroelectric energy used for space heating is also included. These B/C ratios indicate that the proposed hydroelectric project is highly feasible. G. ENVIRONMENTAL AND SOCIAL EFFECTS The study results indicate that the adverse environmental effects of the project will be minor due to the limited scope ~BI-419-9524-I I-o of project activities, the limited nature of the fishery resources in Midway Creek, and the availability of measures to mitigate the potential effects from the construction ana operation of the facilities. Implementation of the project should bring some socioeconomic benefits to Old Harbor. The local payroll will be expanded during construction and some employment should be provided for local residents both for construction and maintenance of the facilities. The project should also bring a dependable and cheaper supply of electric power to the local residents. H. CONCLUSIONS AND RECOMMENDATIONS The studies conducted for this report indicate that the proposed 340 kW hydroelectric project is feasible and that the energy demands of Old Harbor are sufficient to utilize the hydroelectric plant's planned capacity. The proposed project is a more economic means of meeting the area's future electric needs than the base case diesel alternative. Environmental effects of the proposed project are minor. In view of these findings, it is recommended that actions be initiated to implement the project. NBI-419-9524-I I-6 SECTION II INTRODUCTION A. GENERAL Old Harbor is a small village located on the southeast coast of Kodiak Island 50 miles southwest of the city of Kodiak. The village currently relies upon a city-owned diesel generation plant for its electrical energy. Diesel systems for electrical generation have several seri- ous drawbacks, especially in remote locations--availability and cost of diesel fuel, expected shortages and increased expense of fuel in the future, potential mai~tenance problems, and the cost and availability of parts or even whole systems. The installation of hydroelectric generating capacity would potentially alleviate the major problems inherent in the diesel systems and provide dependable generating capacity over a long time span. This section describes the purpose and scope of the study, the physical and economic characteristics of the project area, and the organizational makeup of the participants in the study. 13. PURPOSE The primary purposes of this feasibility study were to prepare a recommendation on the best configuration for develop- ing a dependable source of hydroelectric energy supply for Old Harbor and to determine the engineering, environmental, and economic feasibility of the project. NBI-419-9524-II II-1 The recommended hydroelectric project was compared with a base case plan, defined as a continuation of the present diesel generating units, supplemented with additional future units as necessary to accommodate growth. Earlier studies had deter- mined that these two alternatives were the most promising sources of electrical energy for Old Harbor. However, during the course of this study the Alaska Power Authority requested that a wind power case also be evaluated based primarily on a study by another consultant that was to become available in January 1982. At the time this draft report was completed in mid-February, this information was still pending. A supplement to this draft report wi 11 be incorporated in to the final re- port. C. PROJECT AREA DESCRIPTION Old Harbor is a community with a year-round population of about 350 located on an alluvial plain by Sitkalidak Strait on the southern coast of Kodiak Island. Tbe surrounding mountains rise to a height of 1940 feet, and the village itself is lo- cated in the transition zone between high brush vegetation and alpine tundra. The local sea coast is marked by deep, narrow scoured straits and fjords and steep, rocky sea bluffs. Old Harbor is only accessible by air and water. There are no roads connecting the town with the other villages on Kodiak Island. Old Harbor is served by two flights daily, Monday through Friday, by Kodiak Western Airlines. Charter companies are also available for flights to and from Kodiak, and docking facilities are available in the harbor. Many of Old Harbor's residents are commercial fishermen. More than 30 fishing boats stay in Old Harbor year-round and up to 100 are present during fishing season. The principal catch is salmon, but halibut, crab, and herring are also caught in quantity. Average income per household is $7,242 and the cost NBI-419-9524-II II-2 of living is extremely high. Consequently, 42 percent of the households are estimated to live below the federal poverty level. Most of the residents depend on subsistence activities for certain foods such as duck, seal, deer, rabbit, bear, and berries. The proposed hydroelectric project site is on Midway Creek, which flows into Midway Bay from the northeast about two miles north of Old Harbor. The stream flows through a steep canyon and disgorges on the plain from the nearby mountains. The stream is about 20 feet wide at the water surface at the diver- sion site. The left abutment is visible bedrock. The right abutment consists of glacial drift. Soils along the coastal plain are shallow, and poorly drained soils and high water tables are common. The general plan and drawings of Appendix A show the location and features of the proposed project. The climate of Kodiak Island is dominated by a strong marine influence. The area is characterized by moderately heavy precipitation and cool temperatures. High clouds and fog occur frequently but the area has little or no freezing weather. The humidity is generally high and temperature varia- tion is small. The mean maximum temperature varies from 240F co 60oF. Average rainfall is 60 inches per year. Winds of 50 1:o 75 knots are frequent, with 120 mph winds estimated for a 100-year storm. Icing is an important climatological feature. D. AUTHORITY The Alaska Power Authority (APA) has authorized studies to prepare the "Detailed Feasibility Analyses of Hydroelectric Projects at King Cove, Larsen Bay, Old Harbor and Togiak." This particular report, Volume C, summarizes the studies con- ducted for Old Harbor. APA is an agency of the Department of Commerce and Economic Development, State of Alaska. NBI-419-9524-II II-3 E. SCOPE OF STUDY In general the scope of the study consists of an analysis of the the costs and benefits of a hydroelectric project, a comparison of these costs and benefits with those for the base case plan for the vi 11 age, and an environmental assessment of the effects of the project. To accomplish these goals, the following activities were necessary. 1. Data Accumulation Data collected included existing flow records, topographi- cal mapping, present and future demands for power, applicable laws and regulations, existing reports, and other applicable information that was available. 2. Site Reconnaissance The purposes of the site reconnaissance were to supplement and verify the data gathered, to collect topographical, hydro- logical, environmental, and geotechnical data, and to determine the accessibility of the site. The conceptual design of pro- ject features was established in the field. 3. Site Surveys A topographic survey was conducted at the site of the diversion, penstock, powerhouse, and transmission line in suf- ficient detail for use in final design. 4. Hydrology Hydrologic data were developed from the limited available data. A sui table method was established to prepare a stream- flow table, a flow duration curve, and the seasonal distribu- tion of the flow duration curve. Diversion and flooding problems were also considered. NBI-419-9524-II II-4 5. Geotechnical Investigations Geotechnical investigations were conducted to determine material sources, slope stabilities, and load-bearing charac- teristics of the foundations for all structures in the project. 6. Base Case Plan A base case plan was analyzed that assumed a continuation of the existing diesel generation system and least-cost addi- tions for future generators. Included in this analysis was an assessment of current energy usage and a forecast for the life of the project. The cost of continuing the use of the base case plan provided a basis for determining the value of power at the site. 7. Power Studies Several different types of turbines and a range of instal- led capacities were evaluated to determine the optimal confi- guration. 8. Environmental Overview The environmental investigation was conducted to identify any environmental constraints that might prohibit project development. 9. Design A layout of the project was designed and sizes and capaci- ties of water-carrying, structural, and control components were determined. All features of the project were designed in suf- ficient detail for use in preparing a cost estimate. NBI-419-9524-II II-5 10. Cost Estimates Cost estimates, including direct and indirect costs, were prepared using a present cost base escalated to the anticipated time of construction. 11. Economic Analysis The project was analyzed using the economic criteria of the Alaska Power Authority. The general methodology employed was to compute the present net worth of the costs of the proposed hydroelectric project over a 50-year project life and to com- pare this value to the present net worth of the costs of the base case plan over the same 50-year project life. 12. Environmental Assessment A detailed environmental analysis was conducted based upon the final design and layout of the project. 13. Conclusions ana Recommendations The report presents findings project and recommends a future course of action to followed. 14. Public Meetings Public meetings were conducted in Old Harbor at the begin- ning of the project studies to obtain comments from local citi- zens. Another public meeting will be held in Old Harbor after the Alaska Power Authority has reviewed the preliminary report. The purpose of the meeting wi 11 again be to sol ic i. t public inputs. NBI-419-9524-II II-6 15. Report A draft report was submitted to the APA in February 1982, and the final report incorporating all comments will be submit- ted on April 1, 1982. F. STUDY PARTICIPANTS DOWL Engineers, of Anchorage, Alaska, was the primary con- tractor for the study. DOWL was assisted by two subcon- tractors--Tudor Engineering Company of San Francisco, Cali- fornia, and Dryden & LaRue of Anchorage, Alaska. The primary role played by each of the participants is covered below. 1. DOWL Engineers DOWL Engineers, an Alaskan partnership, performed the pro- ject management function and provided the primary contact with the Alaska Power Authority. DOWL collected basic data, parti- cipated in the hydrology studies, and had the prime responsi- bility for the local coordination activities, geology and geo- technics, and the environmental, ground survey, stream gaging, and wind velocity aspects of the investigation. 2. Tudor Engineering Company Tudor, as principal subcontractor, supplied all hydro- electric expertise for the project. They directed data eollection and conceptual design of facilities; assisted with public meetings; assisted and provided direction in evaluating the base case plan and power values, formulating cost esti- mates, and making the financial and economic evaluation; ana furnished advice on the aspects of the environmental problems that are unique to hydroelectric projects. Tudor prepared the initial draft of the project report. NBI-419-9524-II II-7 3. Dryden & LaRue (D&L) The partners in D&L are electrical engineers registereu in Alaska. Much of the electrical work was accomplished in close cooperation with this firm. Transmission lines ana backup diesel generation facilities were involved as well as questions related to reliability and integrated operation of the proposed system with existing village systems. D&L and Tudor estab- lished the value of power and the present and projected power demands. D&L provided the feasibility designs and cost estimates for the transmission lines and appurtenant electric features. G. REPORT FORMAT Pages, tables, figures, and exhibits in this report are numbered within the secti-ons in which they appear. Within sections, the tables, figures, and exhibits are placed at tne end of the text. References noted in the text are 1 is ted in the Bibliography. H. ACKNOWLEDGMENTS The cooperation ot the many federal, state, and local agen- cies and local residents contacted during the course of the study is gratefully acknowledged. This list includes, but is not limited to, the Alaska Power Administration, the Alaska Department of Fish and Game, the Alaska Department of Trans- portation, the Alaska Department of Natural Resources, the U.~. Army Corps of Engineers, the U.S. Geological Survey, and the U.S. Fish and Wildlife Service. The assistance of the RocKford Corporation and the Locher Construction Company, a subsidiary of Anglo Energy Company, is also acknowledged. Individuals who were especially helpful include Don Baxter of APA, Roger ~mith of ADF&G, and Sven Haakanson and Walter Erickson of vld Harbor. NBI-419-9524-II II-8 SECTION II I STUDY METHODOLOGY A. GENERAL This section describes the general methodologies employed and steps taken to complete the project studies and analyses. In general, the study proceeded in three phases--pre- reconnaissance, field studies, and office studies. Each project phase is described briefly below and the results are covered in detail in the following sections of the report and the appendices. B. PRE-RECONNAISSANCE PHASE This phase consisted of initial data collection and analyses, obtaining access permits, coordination with resource agencies, and evaluation of the existing material and reports. ~ brief 24-hour visit spanning two days was made to Old Harbor by the project team to hold the initial public meeting to inform the residents of project investigation activities. The initial field evaluation of available alternative hydroelectric sites was also made along with preliminary environmental ~~valuations of all sites. Office studies of alternative sites and environmental conditions had preceded the initial field IVOrk. The project team on this initial visit consisted of individuals with geologic, geotechnical, hydrological, environmental, and electrical ~ndividuals participated in evaluating the conducting the field investigations. C. FIELD STUDY PH~SE hydroelectric, expertise. All alternatives and The field studies were conducted several weeks after initial pre-reconnaissance activities, mobilization, and field NBI-427-9524-III III-1 planning were completed. Detailed site investigations spanning several days were made by the hydroelectric engineers to define the location of the project features. They were aidea in this work by the geology and geotechnic team, which also made a detailed investigation of geology and soil conditions following final selection of the feature locations. Field environmental and hydrologic investigations were also conducted in parallel as the field conceptual design work was completed. The field survey team immediately followed the hydro- electric and geotechnical teams to the field to conduct detailed surveys. A stream gage was also established by the hydrology group. Data were gathered from Old Harbor regarding the present and planned generating conditions of the city s~stem. D. OFFICE STUDY PHASE The final and most extensive phase of the study was the office study phase where all data gathered trom the field and all accumulated data and information were analyzed and addi- tional investigations were conducted to complete the project activities. Separate reports were produced for the hydrology, geology and geotechnical, and environmental activities. They are included with this report as Appendices B, C and E, respec- tively. The environmental appendix also includes information on permitting requirements, social impacts, and land status. Project energy planning studies were conducted to define the year-by-year electrical and heating demands of Old Harbor. To meet the requirements, various were analyzed to determine the optimal NBI-427-9524-III I II-2 installed capacities project size and the conceptual design of the hydroelectric project. These tasks were completed with the aid of the maps prepared from the field activities. Detailed cost estimates were then prepared based on the final size of 340 kW and the completed project layouts. The economic analysis was then conducted to complete the project analysis activities, and this draft report was prepared. Following a preliminary review of the report by the Alaska Power Authority, an additional meeting will be held in Old Harbor to solicit public comments. This draft will be circulated to all concerned state and federal agencies. After receipt and consideration of comments, the final report will be compiled. NBI-427-9524-111 II1-3 SECTION IV BASIC DATA A. GENERAL This section describes in general the basic data used in the preparation of the Old Harbor report. Included are hydrol- ogic, geologic and geotechnical data, surveys and mapping, land ownership status, and previous reports. B. HYDROLOGY The primary thrust of the hydrologic studies for the Old Harbor Hydroelectric Project concerned the development of a flow duration curve, an annual hydrograph, and a flood fre- quency curve for Midway Creek. A complete report of the steps taken to achieve those items is covered in the hydrology report included with this report as Appendix B. No streamflow data were available for Midway Creek except for a few sporadic point discharge measurements made in connec- tion with this study. An automatic stream stage recorder has now been installed. The general methodology employed to develop the Midway Creek flow duration and hydrograph was to :f.irst develop an estimated value for the Midway Creek mean annual flow. Dimensionless flow duration curves and hydro- graphs were then developed from the records of a long-term stream gaging station, Myrtle Creek on Kodiak Island. Applying the Midway Creek mean annual flow to the dimensionless curves then yielded a specific flow duration and hydrograph for Midway Creek. NBI-389-9524-IV IV-1 1. Mean Annual Flow The mean annual flow was developed using three different estimating techniques--the modified rational formula, regional analysis, and the channel geomorphology method. The three methods yielded similar values and the Midway Creek mean annual flow was taken as 10.5 cfs. 2. Flow Duration Curve The closest gaged stream with an adequate length of record is Myrtle Creek on Kodiak Island (No. 15297200), 40 miles north of Old Harbor. A comparison of dimensionless curves from three basins on Kodiak Island showed considerable similarity. On this basis, the Myrtle Creek curve developed from 17 years of daily record was adopted as the type of curve for small, mountainous maritime basins in southwest and south-central Alaska. The Midway Creek flow duration curve presented as Figure IV-1 is based on Myrtle Creek scaled to the ratio of its respective mean annual flows. 3. Annual Hydrograph Based on the same data and reasoning that went into deter- mining the mean annual flow and the flow duration curve, an annual hydrograph was developed based on monthly flows at Midway Creek. The resulting annual hydrograph is presented in Figure IV-2. 4. Flood Frequency Curve Estimates of flood discharges are based entirely on regional analyses. Regression equations obtained through regional analyses were first applied to the gaged stream to NBI-389-9524-IV IV-2 test their applicability. The basin and climatological characteristics of the ungaged Midway Creek were then entered to obtain the following flood frequency values. QlO = 250 cfs Q25 = 300 cfs Q50 = 340 cfs Qtoo= 400 cfs These data are plotted on a frequency curve and presented as Figure IV-3. 5. Potential River Ice Problems A brief evaluation of potential icing at the diversion weir and penstock intake point indicates that potential problems may result from sheet ice and frazil ice formation. Since few data are available, an in-depth study of the extent of the problems and measures to avoid or mitigate them will be necessary during the design phase of this project. C. GEOLOGY AND GEOTECHNICS The purpose of the geologic and geotechnical studies con- ducted for this report was to assess the geologic hazards, establish appropriate design criteria, explore material borrow sites, and provide background information for environmental studies. A complete Geology and Geotechnics Report covering these i terns in detail is included as Appendix C. A summary of the report is included below. 1. Site Topography Old Harbor is located in the south-central portion of K.odiak Island, Alaska, along the shores of Si tkalidak Strait. Si tkalidak Strait is a major feature that opens up to the NBI-389-9524-IV IV-3 Pacific Ocean at both ends. Old Harbor is situated near Sitkalidak Passage, a narrow arm of the Strait separating Kodiak Island from the smaller SitkalidaK Island. Sitkalidak Strait and many of its tributary bays were once filled with ice. As the glaciers retreated and the sea level rose, these former glacial valleys filled with water. They can be classified as fjords. Because multiple glacial advances have brought ice to tnis entire area, the hills are generally smooth and rounded, hanging valleys are common, and valleys tend to have a parabolic cross section. Elevations in the immediate area range to approximately 2000 feet. The proposed stream diversion site is on a creek that is a tributary to Midway Bay and has been named Midway Creek for the purposes of this report. Midway Bay is a small bay that is part of Sitkalidak Strait near Old Harbor and Sitkalidak Passage. 2. Regional Geology Ocean trenches are viewed in geologic theory as sites of large-scale underthrusting of oceanic crustal materials. The sediments that fill these trenches are scraped from the down- going plate and accreted to the overlying plate as this under- thrusting continues. Southwestern Alaska has a long history of being a zone of accretion for deep-sea deposits. The Kodiak Formation that constitutes the bedrock underly- ing the Old Harbor site has been interpreted as a deep-sea trench deposit of Late Cretaceous Age that has been accreted to the continent. Glaciation on Kodiak Island has probably extended from Miocene time to the present. The glacial deposits at Old NBI-389-9524-IV IV-4 Harbor date from Late Pleistocene time. Both till and glacial outwash deposits are present. 3. Site Geology The Kodiak formation that constitutes the bedrock underly- ing the Old Harbor site has been interpreted as a deep-sea trench deposit of Late Cretaceous Age that has been accreted to the continent. These rocks, for the most part, are marine turbidites and range from well-li thified siltstones to fine- grained sandstones. Both till and glacial outwash deposits are present. Midway Creek flows in a narrow gorge through rocks of tne Kodiak Formation, glacial deposits, and colluvium onto an alluvial fan composed of sandy gravel. The bedrocK consists of well-lithified, competent siltstones and very fine sandstones. The proposed east dam abutment is situated in rocks of the Kodiak Formation. The rock is jointed but appears to be compe- tent. Some loose rock must be removed. No major blocks susceptible to sliding were observed. The proposed west abutment is in boulders of granitic rock brought in by glacial activity. The boulders range in size up to 10 feet and can serve as abutment material. There may be a slope stability ooulders. problem caused by erosion around the The route of the road follows an alluvial fan for about 3000 feet, then climbs to a bench in the topography and follows the bench for 1500 feet. Only clearing of vegetation would be necessary for a truck trail on the fan. To reach the bench, extensive cut and fill would be necessary for approximately 75 yards. The terrace is composed of colluvium and boulder till. On the bench, grading would be required, then about 18 NBI-389-9524-IV IV-5 inches of fill should be placed using material brought in from the fan. 4. Construction Materials Gravel is available from the alluvial fan. Less than six inches of overburden will need to be stripped to reach that usable gravel. Boulders of competent, relatively unweatnered granitic rocks are available from the glacial deposits. Tnese rocks are suitable for virtually all types of construction uses. 5. Seismic Hazards The proposed dam site at Old Harbor is in a seismically active area. Strong ground motion is the principal seismic hazard. Recommended design criteria should be based upon a 50- year life of the structure and a base acceleration of 40 to 50 percent of the acceleration due to gravity. Surface faulting or major ground failure is not expected at the dam site. D. SURVEY AND MAPPING A detailed ground survey based on the project configuration marked in the field by hydroelectric engineers was made of tne Midway Creek site between November 2 and 6, 1981. The survey and the drawings produced from it included ground control, penstock traverse (1 inch = 100 feet norizontal, 10 feet vertical) and cross sections, and topographic mapping (1 inch = 20 feet, 2-foot contour interval) and cross sections in the vicinity of the diversion dam and the powerhouse sites. Elevation datum was assumed. Prior high altitude stereo aerial photography of the area was available. This was used to produce a general topography NBI-389-9524-IV IV-6 map (1 inch = 700 feet, 20-foot contour interval, assumed control) of the Midway Creek drainage basin. Old Harbor and the project site are located on the USGS Kodiak A-4 and A-5 15 minute Quadrangle Maps ( 1:63,360; 100- foot contour interval, 1952). Mapping of the recent North Village development was obtained from the Old Harbor Community Map. E. LAND STATUS A map showing the land status in Old Harbor and the project area is presented in Figure IV-4. The diversion weir, penstock and powerhouse locations of the proposed hydroelectric project are entirely within lands of interim conveyance to Koniag, Incorporated, as provi~ed for in the Alaska Native Claims Settlement Act of December 1971 (ANCSA), Public Law 92-203. This interim conveyance includes both surface and subsurface estates. Interim conveyance is used in this case to convey unsurveyed lands. Patent will follow interim conveyance once the lands are identified by survey. The proposed construction of a barge landing in Midway Bay near the mouth of Big Creek and the road construction from the landing to the powerhouse are also located on lands with an interim conveyance classification to Koniag, Incorporated. The r;ransmission route from the powerhouse across Big Creek delta to the townsite of Old Harbor, U.S.S. 4793, is also similarly elassified. The patent on the townsite was issued to the Bureau of Land Management Townsite Trustee. The Trustee has deeded occupied parcels to the residents and some vacant sub- dividea lots to the city of Old Harbor. Other subdivided property remains with the Trustee. A permit would be required for the transmission line and it could be issued by the u.s. Department of Interior after an affirmative resolution by the c:ity council. The extent of the impacts and the easements NBI-389-9524-IV IV-7 required on these lands are dependent upon the final transmis- sion route within U.S.S. 4793. All of the interim-conveyed lands identified above are also part of the Kodiak National Wildlife Refuge as classified and withdrawn by Public Land Orders 1634, 5183, and 5184. All lands that were part of a National Wildlife Refuge before the passage of ANCSA and have since been selected and conveyed to a Native corporation will remain subject to the laws and regula- tions governing the use and development of such refuges. F. PREVIOUS REPORTS Studies of potential power projects for the Old Harbor area are described below. 1. "Water-Resources Reconnaissance of the Old Harbor Area, Kodiak Island, Alaska," by John B. Weeks, 1970. Prepared in cooperation with the Alaska Department of Natural Resources. The purpose of this report was to find a water supply source for Old Harbor village. At the time, 1970, the economy was dependent on the summer salmon fishing season. During the winter, most of the villagers had no employment even though the area was in the heart of the shrimp-fishing grounds. The shrimp were processed in the city of Kodiak, where a high- quality adequate water supply was available. Two potential streams were identified as possible sources of water supply, one of which was Ohiouzuk Creek. The stuay focused on the amount and quality of the water that would be available. 2. "Hydroelectric Power Potential for Larsen Bay and Old Harbor, Kodiak Island, Alaska--Appraisal Evaluation, May 1978 1 " NBI-389-9524-IV IV-8 by United States Department of Energy, Alaska Power Administra- tion. This report presents rough appraisals of potential hydro- electric projects to serve the villages of Larsen Bay and Old Harbor on Kodiak Island. The potential hydroelectric generation plan consists of diverting water from an unnamed stream located about three miles northwest of Old Harbor and dropping it through a pen- stock into a power plant utilizing a net head of 340 feet. The installed capacity would be 600 kW at a cost of $3.4 mill ion. Such a plant would generate an average 1.8 million kWh of usable energy annually. The cost per kW would be $5,700 and the unit cost would be 16 cents per kWh. The study concluded that the project at Old Harbor has potential only as a run-of-stream plant. The plant cannot meet power demands during the winter or during dry periods in the summer. It would have to be operated in conjunction with a diesel plant, and the value of the hydro would be based on the fuel oil saved. The approximate value of diesel-generated power using $1.00 per gallon oil at 11 kWh per gallon is 9.1 cents per kWh. With a demand of 2 million kWh/year, the cost ' of hydro power would be 16 cents per kWh. With a larger demand, it would be 11 cents per kWh. The Old Harbor project ls, therefore, of doubtful feasibility according to this study. 3. "Report of Geologic Investigation--Old Harbor, Larsen Bay and Port Lions--Kodiak Island, Alaska," 1978, by Robert M. Retherford. At the request of the Alaska Power Administration, this geologic study was. made of the hydropower site proposed in the Alaska Power Administration report listed as report number 2 above. NBI-389-9524-IV IV-9 The report covered general geology of the Old Harbor area and site geology for the powerhouse, penstock route and dam site. It also made recommendations for future geologic explor- ations. 4. "Small Hydroelectric Inventory and Villages Served by Alaska Village Electric Cooperative," prepared for United States Department of Energy, Alaska Power Administration, by AVEC Engineers, December 1979. The report identified two potential sites. Site 1 was evaluated and considered to be infeasible at that time. Site ~ was still under investigation. Site 1 was the same site studied in the May 1978 APA report, located three miles north- west of Old Harbor. The plan was based on a 600 kW power plant producing 1.8 million kWh of usable energy annually. Site 2 uti 1 ized a site six miles north of Old Harbor. If the results of the appraisal were favorable, it was proposed to carry out feasibility studies. The site is located in the Kodiak National Wildlife Refuge. 5. "Regional Inventory and Reconnaissance Study for Small Hydropower Projects--Aleutian Islands, Alaska Peninsula, Kodiak Island, Alaska," by Department of the Army, Alaska District, Corps of Engineers. Prepared under con tract by Ebasco Ser- vices, Incorporated, July ·1980 draft--October 1980 final. The purpose of this study was to provide a reconnaissance- grade report outlining the potential for hydro power develop- ment at each of 36 isolated communi ties stretched over 1500 miles in the Aleutian Islands, the Alaska Peninsula, and Kodiak Island. At Old Harbor, three potential power sites were analyzed. Site 1 is located on an unnamed stream eight miles north of Old NBI-389-9524-IV IV-10 Harbor. Site 2 is located on an unnamed stream four miles north-northeast of Old Harbor. Site 3 is located on an unnamed stream three and one-half miles northeast of Old Harbor. The report presents a listing of the existing energy source, demographic characteristics, economic characteristics, land ownership, and environmental concerns. Conclusions reached were shown in the following table: Site No. 1 2 3 1 2 3 Installed Capacity 2280 680 340 2280 680 340 Plant Factor Percent 67 67 67 42 42 42 Total Project Cost $6,685,000 2,896,000 2' 356", 000 6,685,000 2,896,000 2,356,000 Annual Cost kWh 0.151 0.076 0.075 0.154 0.154 0.094 Benefit/Cost Ratio 1.38 2.69 2.73 1. 33 2.44 2.25 6. "Reconnaissance Study of Energy Requirements and !\.1 terna ti ves for Akhiok, King Cove, Larsen Bay, Old Harbor, Ouzinkie and Sand Point, 11 prepared for Alaska Power Authority by CH2M HILL, May 1981. The purpose of the study was to identify and assess the present and future power needs of each community and to assess the power project alternatives available to each community. It served as a basis for recommending more aetailed data collec- tion activities, resource assessments, or detailed feasibility studies of one or more specific power project alternatives. The study reported that Alaska Village Electric Coopera- ·:ive, Inc. (AVEC), records show that 274,000 kWh was generated 1n 1979, with a peak demand of 105 kW. The load factor was 30 NBI-389-9524-IV IV-11 percent. During the next 20 years, a 70 percent increase in generation requirements is projected. The AVEC Generation system consists o-r two 155 kW, 1, 800- rpm Caterpillar SR4 units. Although the system is only three years old, outages are common. Ohiouzuk Creek was selected as the preferred hydro power project because it would create few significant environmental impacts, is close to the community, and is approximately equal in cost to the other hydroelectric power projects. The project would have an installed capacity of 296 kW and produce an average annual energy amounting to 1,280,000 kWh, assuming a 50 percent plant factor. Total cost of the project would be $2,340,000, or a unit cost of $7,905 per kW. 7. "Summary-Reconnaissance Study of Energy Requirements and Alternatives for Old Harbor,'' prepared for Alaska Power Authority by CH2M HILL, July 1981. This study presents the results of the study listed as No. 6 evaluating energy requirements and alternative electricity sources for the community of Old Harbor. The recommended project was the Obiouzuk Creek project describea unaer report number 6. NBI-389-9524-IV IV-12 l 56 I 48 I I 40 \ I 32 24 \ I I .~ I I I I I 16 i\ I I ~ I I \ -a U) -0 - I " MEAN ANNUAL FLOW 10.5 cfs l "-J. I I l I I I" I ! I l ~ I I I ! I ~ 0 ...J 0 IJ.. 0 I 1 ............... I I I l I I I ~ 20 40 80 100 60 PERCENT { 0/o) OF TIME FLOW EXCEEDED MIDWAY CREEK FIGURE FLOW DURATION CURVE N-1 -en -u - 35 ,....---.,..---~-,--.---.,.-_ .... ·-.·.·.·.·.·.-r·.·.· ---rl--rl---rl---rl---rl-1 llflllf)tf\.,..-ESTIMATEO RANGE OF AVERAGE 1 ~fft<>~ MONTHLY FLOWS 7 OUT OF 10 I :r: i!ii YEIARS I I 30~~~~~~~-4~~~~r-~--~r-~----r-~---- 111llllillllllil!i~!!lli •••••••••••••••••••••.•••••••••••••••••••••. •· rt ••··•··••·••·:•:.•••••! 1, •••••••••••••••••• :.,.,. 0~--~--~--~--~~~--~~----~~----~~--~ JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MONTH MIDWAY CREEK AVERAGE MONTHLY FLOWS FIGURE Bl-2 EXCEEDANCE PROBABILITY 90 80 70 60 50 40 30 20 10 5 2 I 0.5 0 .1 '.~-~--0 '''7:· >"'' ,, .:-:n-::om'<, v::x~ i' ,:_co ''t c\:' j . :';::: _: ';.i'''"·' i "··---··:±::· f·-·-··+·-·-·· ---...... -. i ........ ,:::::;::.:: ~ : .. : ... ;.::~ .. -::-::: ~;==,.-:-..... =r-· . 1·.. '-·-+··-.. :.. I " ....... : ..... , ......... j ..... 1.::__ . ·--,;..;• J ..... ........ ' ' t ·-····-. r·-- --· ,__ --1-· .•. , .... f •. ' ' ~-~--i ···+--l~~~~·-+·~--~~~-+7~~~~~-+~~"-~-.. ··-~1---·-~--f ··-';,_ --t .. ·--+c ---+~-r -~~~~~~~4 ; ' ' ;c AVERAGE RETURN PERIOD IN YEARS MIDWAY CREEK FIGURE PEAK FLOW FREQUENCY CURVE 1:2:-3 / 5 I D A K r K A L. PROJECT PLAN -----. SHEEP ISLAND \ ~ \ \ \ \ ~ ...r / 0 2. 4 I.L 4 1i MILES Z •NATIVE CORPORATION INTERIM CONVEYED OR PATENTED--~ {INTERIM CONVEYANCE IS USED FOR CONVEYED UNSURVEYED LANDS PATENT WILL FOLLOW I. C. ONCE THE LANDS ARE IDENTIFIED BY SURVEY) I ---~ATIVE CORPORATION SELECTION n UNENCUMBERED U.S. F. AND W. S. LANDS L _ _J m:Jm PRIVATE LANDS {GENERAL AREA) STATE OWNED D ~ITY AND TRUSTEE LANDS ON DECEMBER 6, 1980, OLD HARBOR NATIVE CORPORATION A {VILLAGE CORPORATION) MERGED WITH THE REGIONAL CORPORATION, KONIAG INC THE MERGED CORPORATION OWNS THE SURFACE AND SUB-SURFACE RIGHTS TO THE LAND THAT WAS CONVEYED TO THE VILLAGE CORPORATION. 0 OLD HARBOR HAS A FEDERAL TOWNSITE, USS 4793, WITH PATENT ISSUED TO THE BLM TOWNSITE TRUSTEE THE TRUSTEE HAS DEEDED OCCUPIED PARCELS TO RESIDENTS AND SOME VACANT SUB-DIVIDED LOTS TO THE CITY. OTHER SUB-DIVIDED PROPERTY REMAINS WITH THE TRUSTEE. A PERMIT TO CROSS TRUSTEE LAND MAY BE ISSUED BY THE U.S. DEPT OF INTERIOR, BUREAU OF LAND MANAGEMENT AFTER AN AFFIRMATIVE RESOLUTION BY THE CITY COUNCIL STATE OF ALASKA ALASKA POWER AUTHORITY ANCHORAGE, ALASKA OLD HARBOR HYDROELECTRIC PROJECT DOWL ENGINEERS ANCHORAGE, ALASKA LAND STATUS MAP TUDOR ENGINEERING COMPANY SAN FR ANQSCO, CALIFORNIA FIGURE -4 SECTION V ALTERNATIVES CONSIDERED A. GENERAL The original request for proposals for this project specified a site on Ohiouzuk Creek, as recommended by previous studies, to be assessed for hydroelectric feasibility. How- ever, during this initial phase of the work, the Alaska Power Authority also requested that other alternative sites in the general vicinity of Old Harbor be evaluated at a reconnaissance level to confirm, prior to more detailed study, that Ohiouzuk Creek was actually the optimal site for development. This section summarizes the alternatives considered during this phase of the work and presents the reasoning that led to the conclusion that development of the recommended Ohiouzuk Creek project was not practical and that the best available alterna- tive was a site on Midway Creek, four miles northeast of Old Harbor. B. ALTERNATIVE PROJECTS Locating a physically and economically viable hydroelectric power project in the vicinity of Old Harbor presents certain difficulties. Adequate head is readily available in two streams near the town, but geologic conditions and small drainage areas make the sites undesirable. Larger high-head basins with fewer geologic drawbacks can be found farther north and east, but transmission and access costs are high. Four sites in addition to the Ohiouzuk site were consid- ered. All five sites had been proposed in prior studies. Map and office studies eliminated three sites and two sites were subject to detailed ground reconnaissance before the Midway NBI-389-9524-V V-1 Creek site was selected. Table V-1 lists all the sites consid- ered and their characteristics, and the site locations are shown on Figure V-1. For comparison, the power output estimates from Table V-1 are based on the average annual flow developed in this study, which corresponds to the 30 percent flow duration or availabil- ity and on gross head less penstock losses. The values there- fore may differ from installed capacities suggested in the prior reports. Transmission lines are assumed to terminate at the existing diesel power plant located 0.6 mile northeast of the old town. C. DESCRIPTION AND EVALUATION Preliminary evaluation of the sites was made on the basis of prior reports and map and stereo air photo interpretation. Final evaluation and the selection of the Midway Creek site (Site 2) as the best alternative was made by the field team while they were in Old Harbor. The selection was based on information similar to the data in Table V -1. tie ad, flow, and penstock length were measured in the field at both Sites 1 and 2 before a selection was made. Primary consideration was given to the ability of the alternative projects to meet Old Harbor's projected power needs versus the relative constructibility and cost of the required structures. Geotechnical problems, relia- bility of the water supply, length of the penstock and the access road and the transmission line, and environmental ef fee ts were major considerations. The following discussions highlight that evaluation. Site 1 was described in the request for proposals for this feasibility study and was recommended in the CH2M HILL recon- naissance study (1981). The site is located on Ohiouzuk Creek, which enters the Sitkalidak Strait one mile south of the edge of town. Direct, easy access along a narrow coastal terrace NBI-389-9524-V V-2 a.nd good bead potential made this site initially very attrac- tive. Tbe Obiouzuk canyon bad not been visited during previous reconnaissance activities for tbe prior studies. Detailed reconnaissance over tbe length of tbe proposed project revealed major geotechnical problems. Tbe 50-to 150- foot-deep canyon is cut through weathered siltstones at slopes of 1: 1 wi tb occasional vertical eli ffs. Numerous landslides, particularly in tbe upper reach, extend into tbe narrow stream- bed. Tbis upper reach (Site 1a) was considered unconstructible at acceptable costs by all members of tbe field team. A lower diversion dam site (Site lb) would provide a di ff icul t but constructible penstock route at tbe cost of losing 40 percent of the available hydraulic head. An additional disadvantage of tbe Obiouzuk site is its very small drainage area and the attendant reduction of flow reliability. Site 2 is located on tbe opposite side of Old Harbor near the bead of Midway Bay. Tbe site is mentioned in both the Ebasco ( 1980) and CH2M HILL ( 1981) reports as Unnamed Creek Site 3. In cant rast to Obiouzuk, tbe penstock can easily be constructed on a series of open terraces tbat lead directly to the power plant location. Tbe diversion dam site also provides tbe option of constructing a moderate-sized detention reservoir at some future date, if one is needed. Wi tb the exception of tbe transmission and access length, tbe Midway Creek site appears to be the most efficient and constructible site found among the four associated feasibility studies. Access would be from the sea (three miles from the village boat harbor), thus eliminating the expense of a 150-foot bridge across the tidal mouth of Big Creek and a road along the transmission line route. This site was selected for detailed feasibility analysis. Site 3 is located two to three miles northwest of the landing strip. It was originally proposed by the Alaska Power NBI-389-9524-V V-3 Administration as Plan 1 (1978). It derives its water supply from a transbasin diversion eastward from two high mountain basins that drain westward into Barling Bay. In order to intercept both streams, the penstock must be placed in a deep cut through the divide or a pair of conduits must extend a considerably greater distance up each stream. The report concluded that the cut would have to be at least 50 feet deep and that it would result in excessive construction costs. Site 4 was proposed by Ebasco (1980). The site is located in the upper Big Creek basin, seven miles north of the town. From the power standpoint, this excellent site is capable of supplying eight times Old Harbor's projected demand. It should be reconsidered in the future should Old Harbor's power demand increase greatly beyond present expectations. However, under present power projections, it is improbable that the cost of the long access road and transmission line could be economi- cally justified. Site 5, also considered in the Ebasco report, is located two miles northwest of the Midway Creek site on the same escarpment. It has the classic hydropower configuration of a lake outflow descending a steep face. A comparison of water supply potential, construction difficulty, and distance from Old Harbor made it less attractive than Midway Creek. NBI-389-9524-V V-4 Drainage Area No. Steam (sq mi) la Ohiouzuk Creek 1.7 1b Ohiouzuk Creek 1.8 2 Midway Creek 2.2 3 Barling Bay Tributary 4.6 4 Big Creek, upper 5.4 5 Big Creek Tributary 0.4 NBI-389-9524-V-1 TABLE V-1 ALTERNATIVE PROJECTS OLD HARBOR AREA Average Gross Penstock Flow Head Length (cfs) (ft) (ft) 8.1 250 3900 8.6 155 3000 10.5 295 2200 26.0 340 5200 54.0 410 4500 2.4 820 2400 Transmission Power Line Remarks (mi) (kW) 0.9 125 Difficult site 0.9 80 3.0 340 Selected 1.6 490 Trans- basin 6.2 1400 3.3 130 OLD HARBOR FIGURE AL TERNAT!VE PROJECTS :ll:-1 SECTION VI RECOMMENDED HYDROELECTRIC PROJECT .\. GENERAL Hydroelectric power plants transform tbe energy of falling water (head) into electrical energy. In general, a hydro- electric power project consists of a dam to produce the head or to divert stream flows; an intake and penstock or flume to :onvey the water to the hydraulic turbine; the turbine itself, which is coupled to a generator to produce electrical energy; accessory electrical equipment; and a transmission system to transmit the energy to a distribution system or user. This section describes these features as they are specifi- cally adapted for the Old Harbor Hydroelectric Project and the methodologies used in selecting the type of turbine and generator, the size and number of units and the configuration of the penstock and power plant. Field constructibility, project energy production, and project operations are also discussed. B. RECOMMENDED PROJECT DESCRIPTION In general, the features of the recommended project consist of diversion facilities that include a low weir and an inlet structure that will be located on Midway Creek, which enters Midway Bay three miles northeast of the airstrip and two miles from the North Village development. The diversion weir will divert water into a 24-inch-diameter penstock at a narrow point in Midway Creek. The penstock will descend 2200 feet to a powerhouse with installed capacity of 340 kW. From the powerhouse a transmission line will extend about three miles to the village of Old Harbor. Access to the powerhouse and other NBI-389-9524-VI VI-1 facilities will be provided by builaing a road about one-half mile in length to Midway Bay and a dock so that necessary support for operations and maintenance can be furnished by boat from Old Harbor. This alternative was chosen to avoid building a three-or four-mile road directly to Old Harbor. Such a road would have to incorporate an expensive bridge crossing in the area where Big Creek and Midway Creek enter Midway Bay. These features are presented on Plates II through VI in Appendix A and are described more specifically below. Exhibits VI-1 through VI-4 show photographs of the project area and the proposed locations of project features. The diversion weir will consist of a prefabricated steel module that wi 11 be bolted to a concrete apron. The attitude of the upstream face of the gate will be about 45 degrees from vertical and the gate wi 11 be fit ted with back supports. The steel weir module will be connected by a pin at the base and the upper section will be supported by steel struts. A neo- prene flap will provide the necessary water tightness at the connection of the weir diaphram to the apron. A prefabricated steel inlet structure will be located at the left of the weir. The 24-inch-diameter penstock will be about 2200 feet in length and will consist of both steel and fiberglass sections constructed along the left bank of the creek from the diversion weir to the powerhouse. The penstock will consist of buried fiberglass pipe whenever possible to eliminate the need for anchor blocks. Steel pipe will be used where rock foundation material is encountered or where other reasons dictate above- ground installation. Typical penstock access road sections are shown on Plate III of Appendix A. The power plant at the terminus of the penstock will have an installed capacity of 340 kW and it will utilize an impulse- type turbine and a synchronous-type generator. NBI-389-9524-Vl VI-2 The operating head will be 273 feet, with a design dis- charge of 19.4 cubic feet per second (cfs). The 340 kW rating ls based on assuming a nominal turbine efficiency of 83 percent. It is possible that a turbine manufacturer may guar- ;:Lntee a higher turbine efficiency; if so, this wi 11 increase the turbine-generator rating proportionally. With reasonable turbine efficiency the turbine-generator will perform satisfac- torily on turbine discharges as low as 10 percent of rating. Turbine discharges as high as 48 cfs will not cause a problem ·Jr create excessive maintenance costs for the turbine-generator llni t. (A detailed explanation of the turbine-generator selec- tion process is included in the following subsection.) The turbine-generator and all other equipment except the power transformer will be placed indoors at the powerhouse site. The turbine, speed increaser, flywheel, and generator will be shipped preinstalled on fabricated skids and no field assembly or alignment of those components will be necessary. The powerhouse construction will utilize a reinforced- concrete floor slab and a prefabricated metal building about 30 feet by 34 feet to house the equipment. Permanent lifting facilities will not be provided; however, an oversized equip- ment door will permit portable lifting facilities to be used if they are required for a major overhaul. Since equipment of the type being used is very rugged, the normal annual overhaul functions should not require the lifting of heavy equipment sections. The three-phase power transformer will be mounted on a pad and placed outdoors adjacent to the powerhouse structure. A chain link fence with a barbed guard at the top will encompass the transformer and form the switchyard enclosure. The generator breaker will be inside the powerhouse. NBI-389-9524-VI VI-3 The transmission line from the powerhouse switchyard to the village of Old Harbor will utilize a transmission voltage of 12.47 kV. The configuration of the line will be single pole with singlw cross arms. Poles will be located at 350-foot intervals with the lines running along the centers of the cross arms. A sketch showing the detailed configuration is included in Appendix A as Plate VI. C. TURBINE-GENERATOR SELECTION In the selection process, the type of turbine and type of generator were first tives and the installed incremental cost/benefit selected from the available al terna- capaci ty was then determined by an economic analysis. This selection process is described below. 1. Description of Available Turbines Conventional turbine equipment that is commercially avail- able is classified either as impulse or reaction turbine equipment. An impulse turbine is one having one or more free jets discharging into an aerated space and impinging on the buckets of the runner. The jet size increases as the head on the tur- bine decreases. For low-head applications the cost of the impulse turbines is generally not competitive with the reaction type. The impulse turbine can, however, be operated economically on heads as low as 150 feet. For the 273-foot operating head of this development, there are two sui table types of impulse turbines, Pel ton and Turgo. In the Pelton type the jet impinges the runner near its extremity and in the plane of the runner. In the Turgo type the jet impinges the runner from the side about mid-runner. For the same hydraulic conditions, the Turgo type will operate NBI-389-9524-VI VI-4 at about twice the speed of the Pel ton type. There is very little difference between the two types in either efficiency or methods of control. A Francis turbine is one having a runner with a large :1umber of fixed blades attached to a crown (top) and a band (bottom). The dimensional configuration of the runner is designed to suit the head conditions of the application. Designs are commercially available to suit head conditions ranging from 15 to 1500 feet. In general the Francis turbine is not competitive with the propeller type below a head of about 60 feet. A propeller turbine is one having a runner resembling a propeller with a small number of blades, usually four, five or six, to which water is supplied in an axial direction. The blades are attached to the hub of the runner. The blade angle is adjusted to suit the head conditions of the application. Runners are available in either fixed-blade or adjustable-blade designs. The suitable head range of propeller turbines is from 15 to 110 feet. The 273-foot head of the Old Harbor Project is beyond the head range of the propeller turbine. Accordingly, this type of turbine was not included in the study. In addition to the impulse and reaction turbine, a proprie- tary design called the Ossberger turbine is available for head ranges from 15 to 500 feet. The runner design is classified as a cross flow that derives energy from both impulse and reaction turbine principles. Water is forced through a rectangular cross section and guide vane system and then through the hori- zontal runner blades. This flow pattern has the unique advan- tage of working out refuse such as grass and leaves and melting snow and ice that may be forced between the blades of the runner as the water enters. Any quantity of water from 16 percent to 100 percent of the design flow is usable with optimum efficiency. NBI-389-9524-VI VI-5 2. Description of Available Generators Generators can be of the synchronous or induction type. Induction generators are often considered more practical for the smaller turbine-generator installations because they cost less and require less maintenance. They require no excitation and need only a squirrel-cage rotor that uses no wire windings or brushes. Furthermore, they do not run at exact synchronous speed and complex equipment is not needed to bring them on line. They cannot be used to establish frequency, however, and must be connected to a system with synchronous generators because they take their excitation from system current. The generators produce electric energy with a high degree of efficiency. Synchronous generators are usually three-phase star or Y- connected machines with one end of each winding connected together in common and the other ends used as line terminals. The alternating-current synchronous delivers its induced alternating generator, or alternator, current directly to the external circuit. It is used where transmission is to be sent over long lines. The alternating current can be transformed to the desired transmission voltage. For this development the synchronous generator is used because it is necessary to establish frequency. 3. Selection of Turbine Type As previously discussed, the 273 feet of head available for the Old Harbor Hydroelectric Project is suitable for operating either a reaction turbine (Francis) or impulse turbine (Pelton or Turgo). For the size of this unit, the costs of equipment delivered at the job site are about equal. Installation costs are generally lower for the impulse types since few imbedded parts are necessary. NBI-389-9524-VI VI-6 Any change in the rate of penstock flow will set up a pressure wave that increases the penstock pressure when the flow rate is decreased and lowers the penstock pressure when the flow rate is increased. Destructive pressure risks, known ~s water hammer, are possible if the flow is suddenly stopped. This water problem can be limited by building a surge <:!hamber near the power plant, by installing a bypass valve (known as a pressure-relief valve) at the power plant, or by a combination of both methods. The penstock gradient is fairly uniform from the penstock intake to the power plant. A surge chamber, to be effective, would have to be near the power plant and more than 200 feet high--not a very practical solution. A bypass valve would have to be capable of discharging the same amount of water as the turbine and in addition would have to be able to dissipate the same hydraulic power as the turbine. A valve of this type can be constructed for a modest cost, 10 percent of the turbine cost. On a Francis turbine, the penstock flow is controlled by the opening and closing of the turbine wicket gates. An electrical load rejection will cause the wicket gates to close as fast as is permitted by the turbine governor. Too slow a closing allows the turbine-generator speed to rise to destruc- tive velocities. Too fast a closing results in high penstock water hammer pressures. The use of a turbine bypass valve and proper governor setting can hold the rise in both the speed and water hammer pressure within reasonable limits. A sudden decrease in electrical load initiates signals from the turbine governor that cause the bypass valve to open enough to maintain a near-constant penstock flow. The bypass valve then slowly closes under controlled conditions and the rise in water hammer pressure is negligible. NBI-389-9524-VI VI-7 Impulse turbines are equipped with a jet deflector. The jet deflector intercepts and deflects a portion of the jet or, in the case of a load rejection, the entire jet away from the runner. Under this condition, the rate of flow in the penstock is constant until the needle valve closes, under control of the governor, at a rate slow enough to keep the water hammer pres- sure from materially increasing the penstock pressure. The guide vanes of an Ossberger turbine serve the same function as the wicket gates in the Francis turbine. Both turbines have hydraulically similar relationships to the pen- stock. The previous discussion for the Francis turbine is applicable to the Ossberger turbine. Using a Francis (reaction) turbine on this development would require the use of a bypass valve. The bypass valve and its controls increase the overall power plant costs more than installing an impulse turbine. On this basis, the impulse turbine was selected. 4. Selection of Number of Units Every turbine is most efficient within a range of flows, with decreasing efficiency occurring beyond this range. Consequently, more power can usually be generated if two or more small turbines are selected rather than one large unit. For example, two turbines, each rated at 50 percent of design flow, will produce more energy turbine rated at 100 percent of turbines will generally cost 30 the single turbine. The extra the two units must therefore using two units. over the flow range than one design flow. However, the two percent to 70 percent more than value of the energy produced by make up for the extra cost of In the specific case of Old Harbor, the impulse unit to be usea is very efficient over the anticipated range of flows; the NBI-389-9524-VI VI-8 relatively small extra energy that would result from the use of two units would not justify the extra expense. A single unit was therefore indicated. 5. Selection of Size of Unit The selection of turbine-generator size is primarily a :natter of economics. The larger the turbine size, the larger the flow that can be accommodated and the more energy that can be generated; however, the cost is higher. Comparisons were therefore made of the incremental costs and benefits associated with increments in size. As long as the incremental benefits exceeded the incremental costs, it was economically justified to install the larger capacity. Five turbine sizes in all were investigated for the Old Harbor Project. The sizing was based on turbine-generator capacities based on flows corresponding to the 35 percent to 15 percent range of exceedance values on the Midway Creek flow duration curve, Figure IV-1. A value of 273 feet of hydraulic head (gross head minus losses) was used in all cases. The average annual energy production for each size was calculated using the Midway Creek flow duration curve. For a given hydraulic head, the area under such a curve within the generation limits of the particular size and type of turbine under analysis represents the available energy. The result of the analysis is presented in Table VI-1. As shown, the range of flows investigated is from 9.7 cfs (at 35 percent exceedance) to 19.4 cfs (at 15 percent exceedance) with installed capacities of 175 kW to 340 kW and corresponding average annual energy values of 0.97 million kWh to 1.31 million kWh. NBI-389-9524-VI VI-9 The incremental benefits for the sizes analyzed were com- puted using the differences between the 50-year present worth of the energy for each additional increment and the data and assumptions presented in Section VII, Project Energy Planning, and Section IX, Economic Analysis. The incremental costs were based on the differential costs of the installed unit. The results of the analysis are presented in Table Vl-2. The incremental benefits far exceeded the incremental costs for all size increases up to and including the largest size reviewed, 340 kW at the 15 percent exceedance point, which indicates that this is the optimal size studied. Judgment was the deciding factor not to size the unit for flows in excess of the 15 percent exceedance value. Increasing the turbine dis- charge somewhat beyond this point would probably be economical but it would decrease the energy available on the low-flow portion of the flow duration curve and would not materially increase the annual energy generation. The recommended 340 kW selection would make available all the energy represented by the flow duration curve between the 15 and 87 percent time exceeded. D. FIELD CONSTRUCTIBILITY For the recommended project, various prefabrication opera- tions and field procedures would be utilized that would mini- mize field construction time and also minimize the use of highly specialized construction skills. The diversion weir module and the inlet structure wculd be shop-fabricated welded-steel structures with shop-applied protective coatings. After fabrication in Anchorage or Seattle, they would be shipped wholly assembled to the field. The field installation of these structures would consist of simply bolting the weir and inlet structure into place on the concrete apron. NBI-389-9524-VI VI-10 The 24-inch-diameter penstock would consist of either steel or fiberglass, depending on the geologic and topographic condi- tions encountered. The penstock would be steel where rock was encountered and where the penstock would be elevated. All other sections would utilize fiberglass pipe. The steel portions would be placed above ground with steel collars resting on either concrete pads or prefabricated steel. The steel collars would be shop-welded to the pipe during the fabricating process. The pipe sections would be connected with flexible bolted couplings and no field welded connections would be required. The fiberglass sections of the penstock would be buried to eliminate the need for anchor blocks at vertical and horizontal bends. Bell and spigot joints with rubber gaskets would be utilized to permit rapid field installation and the use of relatively unskilled labor. The powerhouse would consist of a prefabricated metal building erected on a concrete base slab. A standardized unit approximately 30 feet by 34 feet would be utilized. Field assembly of the building would be rapid and unskilled labor could be utilized. The turbine-generator, the speed increaser, and the flywheel will be shipped skid mounted, fully assembled and interconnected to the field. The en tire assembly will be bolted in place on the powerhouse slab, the penstock will be connected, the electrical wiring will be finished, and the installation will be completed. In summary, the maximum use of prefabricated and preas- sembled components is envisioned. The use of concrete in general and formed concrete in particular has been minimized and all major features can be constructed expeditiously using relatively unskilled labor. NBI-389-9524-VI VI-11 E. PROJECT ENERGY PRODUCTION As mentioned in subsection C-5 above and as shown in Table VI-2, the average annual energy production for the recommended 340 kW installation at Old Harbor is 1.31 million kWh. This value was derived using the flow duration curve rather than the average monthly hydrograph since the data used in deriving the flow duration curve were daily values rather than monthly averages as shown on the hydrograph. However, the hydrograph values have been used to compute the available peak power generation that could be expected per month. Where the hydro- graph values exceeded the maximum turbine design flow t the turbine flow was used for the calculation. The "available peak power" values were then used on a monthly percentage basis to distribute the average annual energy value of 1.31 million kWh to monthly energy values. The results of these compilations are presented on Table VI-3. The monthly power and energy production values are shown on Figure VI-1. These monthly hydroelectric energy values will be used in Section VII, Project Energy Planning, to meet the projected present and future energy demands of Old Harbor. The plant factor, the ratio of energy that could be pro- duced by the turbine-generator if continuously operated at its rating to the annual energy actually produced, is 44 percent for Old Harbor. F. PROJECT OPERATION SCHEME AND CONTROLS 1. Turbine-Generator Controls for the turbine-generator unit will load the unit in response to the connected system demand. A turbine governor will control the turbine needle valve setting that controls the turbine discharge and thus matches the turbine-generator NBI-389-9524-VI VI-12 nlectrical output with the connected system load. A small decrease in the system load will cause the governor to actuate ·:;he jet deflector and a quantity of water will be deflected :·:rom the runner to maintain a constant runner speed. If the .ower load continues, the turbine governor will cause the needle valve to move to a position where the turbine discharge Ls of the correct value and the jet deflector will move out of the jet stream to allow the full jet to impinge on the runner. As long as the connected load does not exceed the ~apacity of the turbine-generator, the electrical frequency can ~e held within approximately plus or minus one-tenth of a ::ycle. The turbine-generator is being operated on an isolated system; that is it is not electrically connected into a grid with other operating generating units. Any overload in the unit will gradually decrease the unit's speed and result in a corresponding lowering of both line voltage and frequency. Minor overloading, probably up to about ten percent, can be tolerated. But an excessive overload can, if continued, cause protective devices to trip the unit. It is feasible to have a hydraulic turbine-generator unit operate in parallel with diesel generating units now being used on the city's electrical system. The hydraulic turbine can be operated as a base load unit and regulate the system frequency. By proper setting of the diesel unit governors, the diesel units can be brought on line and operated during unusual system demands. The turbine-genera tor will be manually started. A manual start implies that operating personnel are present during startup. The operating personnel should physically check the unit. This check will include opening the turbine shut-off valve (if closed) and seeing that water is against the needle valve and all supporting systems are operable. Operating NBI-389-9524-VI VI-13 personnel wi 11 then actuate a single control switch and the turbine-generator will automati.cally start up. When the unit reaches synchronous speed, it automatically goes on line. The provision of enough sophisticated equipment and controls to allow the unit to be started up from a remote location is not proposed. Protective devices on the equipment will be capable of shutting the generating unit down automatically, which would require a manual startup. the equipment will sense The automatic protective devices on the internal temperature of the generator, most bearing temperatures, and critical oil levels. High temperatures and low oil levels can trip the turbine-generator off the line. An alarm will be given before any control device shuts down the generating unit. A pressure sensor will be installed at the penstock intake to function in concert with the turbine governor to protect the turbine during periods when there is not sufficient water to meet the turbine discharge requirements. One of two control sequences will be followed to protect the equipment: 1. The lowering water level at the intake will bring the governor control into a mode where it will match the available water quantity with the turbine discharge. If this reduced turbine discharge will not permit the turbine-generator to produce sufficient power to meet the load demand, then the turbine-generator wi 11 be operating in an overloaded condition as discussed above. 2. If the water level falls to a level where the penstock will not be running full, then the control will take the turbine-generator off the line. NBI-389-9524-VI VI-14 In both cases an alarm will be given prior to shutdown. Routine schedule. maintenance will be performed on a weekly The power generated by the turbine-generator need not be reduced during this maintenance period. The maintenance will include routine checks to verify that (1) all equipment is operating in a normal condition, (2) none of the equipment is being operated at a temperature above normal limits, (3) all lubrication requirements are being met, and ( 4) no discontin- uity exists in electrical wiring, relays, or controls. Overhaul maintenance will be performed on an annual basis and it will be scheduled during the minimum average river flow, usually in March. The turbine-generator will have to be removed from the line and electrical power required by the City System will be provided by the existing diesel generating units. This annual maintenance period will not normally exceed a week. This type of maintenance will include the following items: 1. Areas of wear on the turbine-generator unit will be reviewed and corrective measures will be initiated in cases where wear beyond the allowable limits set by the manufacturer has occurred. 2. Electrical insulation checks will be made. 3. Relubrication will be required under facturer's recommendations. the manu- 4. Verification will be made that all relays and controls are properly set. NBI-389-9524-VI VI-15 2. Diversion Facilities The design of the steel diversion weir provides a hinge at the base of the weir at the connection with the concrete apron. This design allows for periodic lowering of the weir to remove accumulated sediment. The frequency of such a main- tenance procedure would depend on the rate of sediment deposi- tion and the interference of the deposits with the diverted flows. If cleaning is necessary at all, the frequency is not expected to be more than once a year. NBI-389-9524-VI Vl-16 Perc,ent Times TABLE VI-1 TURBINE-GENERATOR SIZING OLD HARBOR Turbine Unit Penstock Exceedance Discharge Head Size I. D. (Percent) (cfs) (feet)_ (kW) (Inches) 15 19.4 273 340 24 20 15.4 273 270 22 25 13.2 269 225 20 30 11.4 274 200 20 35 9.7 279 175 20 NBl-389-9524-VI-1 Annual Energy Generated (million kWh) 1. 31 1.20 1.12 1.06 0.97 Plant Rating (kW) 175 200 225 270 340 TABLE VI-2 PLANT SIZE AND INCREMENTAL COST AND BENEFIT OLD HARBOR Incremental Jan. 1, 1982 Material Net Benefit Incremental Cost with Heating Benefit -----------dollars in thousands---------- 5,496 2.5 191 5,687 2.4 149 5,836 27.2 149 5,985 31.9 228 6,213 Incremental B/C Ratio 76.4 62.1 5.5 7.1 NBI-389-9524-VI-2 Average Month Flow (cfs) --- Jan 6.4 Feb 5.5 Ma::· 3.9 Ap:i~ 8.0 May 22.1 JU'J.e 19.3 July 7.7 Aug 8.6 Sept 14.8 Oct 13.7 Nov 10.3 DEC 6.1 TABLE VI-3 AVERAGE MONTHLY PEAK POWER OUTPUT AND ENERGY GENERATION -340 kW UNIT OLD HARBOR Flow Utilized for Available Energy Head Design Peak Monthly Generation Loss Head Power Energy (thousand (cfs) (feet) (feet) (kW) (kWh) 6.4 1. 70 287 118 67.8 5.5 1.25 287 101 58.2 3.9 0.63 288 72 41.2 8.0 2.65 286 147 84.7 19.4 15.58 273 340 205.5 18.3 15.42 273 338 204.4 7.7 2.45 286 141 81.5 8.6 3.06 285 157 91.1 14.8 9.07 279 265 150.8 13.7 2.27 281 247 145.1 10.3 4.39 284 188 109.2 6.1 1.54 287 112 64.6 Total 1310.1 Nbl-389-9524-VI-3 Percent of Total Annual Energy 5.2 4.4 3.1 6.5 15.7 15.6 6.2 7.0 12.0 11.1 8.3 4.9 100.0 200 150 100 -I 0 0 50 0 .. - lC .t:. ~ ,11£ -> C) cr I.IJ z I.IJ 0 J F M A MONTH MONTHLY ENERGY PRODUCTION .,AVERAGE AI'IINUAL ENERGY 1,310,100 kWh I 400 300 200 I J J ENERGY 100 -:l .Jtt: - Q: I.IJ :a 0 A s 0 N 0 Q. 0 J F M A M MONTH OLD HARBOR HYDROELECTRIC PROJECT MONTHLY HYDROELECTRJC ENERGY AND POWER GENERATION J MONTHLY PEAK GENERATION J INSTALLED CAPACITY 34 0 kW A s 0 POWER N I.J FIGURE JZI-1 MIDWAY CREEK OLD HARBOR SOUTH VILLAGE AND ROAD TO NEWLY CONSTRUCTED NORTH VILLAGE. THE MIDWAY CREEK SITE IS IN THE UPPER RIGHT . EXHIRIT VT-1 DIVERSION WEIR POWERHOUSE PANORAMAS OF PROJECT SITE, LOOKING SOUTHEAST, DIVERSION WEIR EXHIBIT Vl-2 DIVERSION WEIR SITE, LOOKING DOWNSTREAM. POWERHOUSE SITE (FAR BANK) AND STREAM GAGING STATION EXHIBIT VI-3 OLD HARBOR TRANSMISSION LINE ROUTE TO OLD HARROR AERIAL VIEW OF MIDWAY CREEK POWER SITE DIVERSION WEIR POWERHOUSE EXHIBIT VT-'t SECTION VII PROJECT ENERGY PLANNING A. GENERAL This section presents the projected energy usage for Old Harbor over the study period and two alternative means of meeting these projected demands--the base case plan and the recommended hydroelectric project. The potential future demand for power and energy at Old Harbor was estimated during this study in order to establish the electrical requirements that the alternatives could meet. This information was used to size both alternatives and was also used for the overall economic analysis of the project, which is presented in Section IX. B. PROJECTION CONSIDERATIONS The future demand for power and energy at Old Harbor is a function of a number of variables that are difficult to forecast and quantify. These factors include the appliance saturation rate; the effects of cultural factors and tradi- tional life styles on energy consumption; the rate of modernization of the Native life style; the amount of employment in the fish processing industry; the natural variability of the fishery; the amount of new housing built in the area; and numerous political factors such as the 1981 legislation relating to energy projects and programs of tne APA. The installation of the much cheaper hydroelectric alternative will almost certainly alter the pattern of energy and power demand; therefore the forecast presented here is probably conservative. NBISF-419-9524-VII VII-1 1. Appliance Saturation Rate The number and type of appliances owned by each househola, as well as the extent to which these appliances are used, may have a significant effect on the amount of power used in the village. A definite relationship between appliances within a household ana electrical use characteristics is difficult to establish. The actual use of energy is more dependent on the number of people within a given residence--their age, habits, and financial condition. For example, one could predict the annual use of a refrigerator or freezer because this is almost independent of activity and habits. Electric lights, small appliances, and television are Water heaters, washers, dryers, primarily subject to the number very and and susceptible to habits. dish washers vary in use age of the users. For example, hot water use among families with small children or babies is very high. One method of measuring potential future growth and use of appliances is through a concept known as the appliance saturation rate. The estimated present percentages of homes having various types of appliances in Anchorage, the Kenai-Cook Inlet area, and Old Harbor are presented in Table VII-1. This information for Old Harbor is very approximate and was obtained through several interviews with village residents. The residents of Old Harbor report that the Department of Housing and Urban Development intends to build 15 new homes in the village. Since these new homes will be built with the knowledge that the cost of power is going to be reduced, it is very likely that they will include a greater number of appliances than the existing housing. The purpose of presenting the Anchorage and Kenai-Cook Inlet data in Table VII-1 is to provide a comparison with largely urbanized areas that have much greater unit consumption of electrical energy. Appliance saturation rates (and sizes of appliances) for rural Alaskan villages such as Old Harbor can NBISF-419-9524-VII VII-2 be expected to increase in the future. While they may never equal the urban rates of electrical usage, Old Harbor appliance saturation rates indicate that ample room for growth does exist. The base year 1980 rate per residential customer was about 2300 kWh, as discussed subsequently. This apparently reflects a v·ery low electric appliance use. This use was assumed to increase to approximately 4, 150 kWh by the year 2001. The Ebasco (1980) regional inventory assumed that households would increase energy consumption to 6000 kWh per year by the year 1995, exclusive of electric space heating. The new policies permitting opportunities for reductions in price, discussed in the next section, indicate that this projected 4150 kWh annual residential use rate is on the conservative side. 2. The Influence of Price on the Demand for Power The 1981 legislation relating to the projects and programs of the APA will reduce the cost of power to this village by more than one-half. This decrease in power cost can be expected to be accompanied by an increase in use. Data from the Alaska Power Administration have been developed to show the 1980 individual customer use of elec- tricity versus cost for all towns, cities, and villages for which information was available in Alaska. This information is summarized in tabular form in Table VI I-2 and graphically in Figure VII-1. While the data on Figure VII-1 are somewhat scattered, the trend is evident that low power costs result in higher usage and high power costs result in lower usage. In economic terminology, this relationship of price to quantity consumed is referred to as "elasticity" of demand. As indicated by Figure VII-2, unit energy costs of less than 100 mills per kilowatt-hour are generally accompanied by NBISF-419-9524-VII VII-3 high use rates, in excess of 7000 kilowatt-hours per customer per year. As the unit price of power increases, the per customer use tends to decrease, with the 48 Arctic Northwest Villages having energy costs in excess of 400 mills per kilowatt-hour and annual per customer demands of about 2000 kilowatt-hours. The two different utilities listed for Fairbanks provide an even clearer example of the elasticity of the demand for electrical energy; in this case where the cost of energy was 75 .1 mills/kWh the annual demand was 10,519 kWh per customer and where the cost of energy was 122.2 mills/kWh the demand was 5501 kWh per customer. The general conclusion is that in the higher ranges of price there is significant elasticity in demand. costs result in higher energy usage and this Lower energy can also be expected to occur in Old Harbor with the advent of lower prices. The actual amount of higher usage, however, is very difficult to quantify. For purposes of this study no attempt has therefore been made to predict the higher usage other than to incorporate a moderate increase in per customer use of energy in projections covered below. probably on the low side. C. ENERGY DEMAND PROJECTIONS These project ions are For the economic evaluation, a period of 50 years after the proposed date for the hydroelectric project to come on-line was considered. As requested by APA, the period of study was started in January 1982. The demand for power was assumed to increase for 20 years from the beginning of the period of study and was then held at a constant value for the remainder of the period of evaluation. The planning period is the 20-year period during which increases in the demand for energy were recognized, from January 1982 to December 2001. The economic evaluation period extends past the planning period to 2034, 50 NBISF-419-9524-VII VII-4 ...... years after the on-line date for the hydroelectric alternative. The overall energy demand for Old Harbor for purposes of •:tnergy planning has been broken into two primary categories-- direct electrical demand, which includes residential, small ·~ommercial, and school; and space heating demand. Projections for both of these categories and the combined requirements are presented below. No large commercial users such as a cannery exist in Old Harbor. 1. Direct Electrical Demand The general approach followed in estimating direct elec- trical demand was to break down the direct city system demand into general types of customers normally identified by utilities in projecting electrical use in small villages. These include residential, small commercial, and school customers. Residential use represents the largest proportion of usage, and for Old Harbor it amounted to about 45 percent of the total electrical demand. The present and projected demands for power and energy at Old Harbor were taken from the Alaska Village Electric Cooperative (AVEC) Power Requirements Study. Projections beyond 1980 were not directly tied to estimated growth in population. Because of significant changes occurring in the number of residential customers as a result of additional housing units provided through public programs, it was found that residential demand was more closely correlated to the number of housing units than to population growth. This was substantiated by AVEC records of similar communities. Growth in demand from 1980 to 19~5 was heavily influenced by current plans regarding new housing, furnished by government agencies, with an assumed growth rate of 7. 8 percent for that period. Between 1985 and 1990 the growth rate was assumed to be four percent; the annual growth rate was assumed to be three NBISF-419-9524-VII VII-5 percent from 1990 to 2000 and 2.5 percent thereafter. The CH2M HILL study (1981) for Old Harbor assumed a population growth rate of one percent annually but it also recognized the faster growth in housing units. To recognize this differential, CH2M HILL projected an annual increase in electrical demand of 15 percent annually for the city for 1980 and 1981 and two percent from 1981 to 2000. Peak demands were calculated by applying typical load factors for each type of consumer group. Load factor data were derived from AVEC historical data as well as data from other typical utilities. Historically, the load factor tends to improve as the load increases. This improvement is explained by added street lighting, refrigeration, and other loads that tend to diversify the power demand. Projected total annual demands over the planning period to 2001 are shown in Table VII-3. No data were available on the monthly energy demands for Old Harbor. The only source of data found during the course of tne study for monthly demands for small rural villages such as Old Harbor was the 1979 AVEC records for Togiak. Using these data, the monthly percentages of the total annual energy demand were computed. These values are presented in Table VII-4 and they were used in Tables VII-8A to VII-80 to compute the projected monthly energy demands from 1980 to 2001. While the total amount of energy will vary considerably, it was assumed that the monthly use pattern would be fairly similar for rural villages throughout the state; the Togiak values were therefore assumed to be applicable to Old Harbor. At any rate, any error resulting from this assumption is expected to be small. 2. Space Heating Demand The fuel oil rate of use for Old Harbor for 1980 was obtained from the CH2M HILL report ( 1981) on energy NBISF-419-9524-VII VII-6 a.l ternati ves. This report also gave estimated values for 1990 and 2000. These values were then used with interpolated and extrapolated values for 1985 and 2001 to compute the annual heating requirements for Old Harbor in terms of equivalent kilowatt-hours of electrical energy. These values are presented in Table VII-5. Note that the total potential demand was far greater than the expected output of the hydroelectric project and thus it did not constitute a constraint on the economic analysis. The monthly heating demands over the study period were computed using the number of heating degree days per month from the Old Harbor Community Profile and applying the calculated monthly percentages to the annual heat demand values from Table VI I-5. The resulting projected monthly heating demands for 1980 to 2001 are presented in Table VII-6. Because of the daily variation of heating demand, the actual amount of usable waste heat may vary from the total amount computed from monthly values; however, for ease of computation, the variations between the totals and the actual usable amounts were not considered. The estimates of space heating demand as presented herein are conservative. 3. Total Energy Demands The projected annual energy values for direct electrical and heating demands are presented in Table VII-7. The pro- jected monthly energy demands for these same categories are presented in Tables VII-8A to VII-8D. Also shown in the tables are the total electrical demand and the total combined demand (direct electrical and heating demand). The annual energy projections from Table VI I-7 are pre- sented in graphical form in Figure VI I-2, which is a plot of the energy demands for each year of the study period. Also NBISF-419-9524-VII VII-7 shown is the annual hydroelectric energy production for the sizes studied (280 kW to 575 kW). Figure VII-2 presents two separate graphs of the same information--overall data and detailed data. The overall data graph illustrates that a very large proportion of the combined energy demand is heating demand. The detail data graph presents in more detail the relative values of the various demands and available generation values. The monthly energy projections from Tables VII-8A to VII-~D are presented in Figure VII-3, again as overall data graphs ana detailed data graphs. These graphs show the relationship on a monthly basis between the energy demands and the hydroelectric energy available over tne study perioa. The graphs illusrrate the general periods where the hydroelectric energy would have to be supplemented by diesel generation to meet the village needs and when excess energy would be available for space heating. As shown, during an average water year the hydroelectric plant would be sufficient to meet more rhan 90 percent of the village direct electrical needs. D. BASE CASE PLAN The base case plan to meet the projected energy demands presented above was developed assuming that the existing diesel system would continue to be used as the sole source of electric power. The possibility of modifying the existing system to include waste heat recovery was considered; however, since there are no significant heating loads near the plant, waste heat recovery was determined to be impractical. NBISF-419-9524-VII VII-8 The existing diesel plant includes two 155 kW units (155 kW firm capacity) .J.) This firm capacity should be adequate to meet projected demands through the year 1990; however, the capacity will not be adequate by the year 2000. Therefore, it was assumed that the plant capacity would be increased by 150 kW in ten years, increasing the firm capacity to 305 kW. The entire plant would be replaced in the year 2001, and every 20 years thereafter for the entire period of economic evaluation. The 155 kW units would be replaced with 200 kW units, which would increase the firm capacity to 350 kW. This study assumes that existing fuel-storage facilities will be adequate over the 1 ife of the project. Old Harbor receives fuel shipments four times a year, and long-term storage facilities are not a critical factor. The diesel generation system at Old Harbor currently con- sumes about 47,000 gallons of fuel oil per year; this rate can be expected to increase over the next 20 years to more than 96,000 gallons per year. E. RECOMMENDED PROJECT PLAN The recommended project plan for Old Harbor would consist of a 340 kW hydroelectric power plant supplemented by diesel generation. The hydroelectric power plant would become functional in late 1984. An on-line date of January 1, 1985, was assumed for this study. The annual average energy generation is shown on Figure VII-2. The entire existing diesel capacity ( 155 kW of firm capa- city being expanded to 305 kW in ten years) would be required J.J In figuring firm capacity, the largest unit is omitted. NBISF-419-9524-VII VII-9 as standby and backup power. The hydroelectric generation would be adequate to meet the direct electrical demand during most of the year; however, during periods between the end of November and the first of April it would be necessary to sup- plement the hydroelectric generation with diesel in order to meet the direct electrical demand. The full capacity of diesel generation required to meet the direct electrical demand would still be necessary for emergency use. Since the diesel engines would not operate as much under this plan as they would under the base case plan, it was assumed that they would not need to be replaced for at least 30 years. The average annual energy production for the hydroelectric power plant would be 1.310 million kWh, compared to a projected direct electrical demand for electricity of 0.518 million kWh in 1985 and 0. 847 mi 11 ion kWh for the year 2000. The average annual plant factor would be about 44 percent. Diesel genera- tion would be required to meet the direct electrical demand for a small part of the time due to the lack of coincidence between electrical demand and hydroelectric generation. Hydroelectric energy not needed to meet the direct electrical demand would be used for space heating. Using the above criteria, the amount of hydroelectric energy that is available over the study period to meet the direct electrical demands and the heating demands were computed on a monthly basis. The results are presented in Tables VII-9A through VII-90. The resulting net values of hydroelectric energy used for the direct electrical and heating demands will be used in Section IX, Economic Analysis. Note that the "energy accounting" described above and pre- sented in Tables VII-9A through 9D assumes that 100 percent usage can be made of the hydroelectric energy available. This usage level may not be wholly attainable in practice because of the unavailability or breakdown of end-use equipment and dis- NBISF-419-9524-VII VII-10 ...... tribution lines. Also, a system making use of all of the ex- cess hydroelectric energy for heat would not be 100 percent efficient. However, any error resulting from the assumption oi a 100 percent usage rate would likely be small and would be counterbalanced because both the projected demand and the hydroelectric energy output estimates are conservative. NBISF-419-9524-VII VII-11 TABLE VII-1 ELECTRICAL APPLIANCE SATURATION RATES OLD HARBOR Consumption Kenai- per House-Cook Old ~.iance Household 1/ Anchorage l/ Inlet l/ Harbor 2 1 (kWh) ------percentage of total households----- Lights 1,000 100 100 Small Appliances 1,010 100 100 Refrigerator 1,250 100 100 Freezer 1,350 42 56 Water Heater 3,475 100 94 Television 400 156 100+ Video Tape Recorder ~ ~ ~ Washer 70 50 85 (Water) (1 '050) Dryer 1,000 71 76 Dishwasher 230 50 31 (Water) (700) JJ Values are for 1978 from "Electric Power Consumption for the Rail belt: A Projection of Requirements, 11 Technical Appendices, Institute of Social and Economic Resources, May 23' 1980. ~ The percentage of residences having the listed appliances is based on estimates from several Old Harbor residents usage rate data are not available nor is the mode split between electrical and other sources of energy known. ~ Not available. NBISF-419-9524-VII-1 100 100 99 100 90 100 50 90 50 5 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 2 8. 29. 1./ TABLE VII-2 UNIT COST AND ENERGY DEMANnli ALASKA Cost Location (mills/kWh) 5 Villages (Southeast) 298.7 Haines 144.3 Juneau~/ 45.7 Juneatdf 92.2 Ketchikan 58.4 Metlakatla 31.5 Petersburg 123.5 Sitka 49.8 Skagway 133.9 Wrangell 156.3 Yakutat 152.7 Anchorag4~ 37.5 AnchoragSf; 33.6 Anchorag~ 45.8 Glenallen, Valdez 131.5 Homer 35.9 Kodiak 149.3 Seward 54.0 Fairbankst~ 122.2 Fairbanks.=-: 75.1 Fort Yukon 245.3 Tanana 269.9 48 Villages (Arctic Northwest) 422. 1 Barrow 129.8 Kotzebue 199.7 Bethel 177.4 Dillingham 151.9 McGrath 233.5 Naknek 174.5 Data obtained from "Alaska Electric Power 1980," Sixth Edition, August 1981, United of Energy, Alaska Power Administration. table on page 40, "Energy Sales, Revenue, were used to develop this table. Demand (kWh/Customer) 3,996 5,680 7,775 7,775 8,528 17,981 6,355 8,483 5, 879 4,689 7,170 9,124 11' 982 14,800 5,890 12,644 5,871 6,694 5,501 10,519 1,669 5,992 2, 044 4, 395 5,290 4, 590 5,000 1, 735 5,524 Statistics, 1960- States Department Values from the Customers--1980," ~/ Juneau, Anchorage and Fairbanks are served by more than one utility. Each listing is for a separate utility. NBISF-419-9524-VII-2 TABLE VII-3 PROJECTED ANNUAL ENERGY DEMAND OLD HARBOR Year 1980 1985 1990 2000 2001 Type of !.; ~umber of 1/2 / Consumer Residential Small Commercial Public & School Total System Residential Small Commercial Public & School Total System Residential Small Commercial Public & School Total System Total System Total System Customers 71 4 7 82 90 4 7 101 95 5 8 108 110 112 --------------- JJ A'ilEC Power Requirements Study Annual Energy }j Demand (kWh) 164,000 19,000 172 1 000 355,000 290,000 28,000 200 1 000 518,000 338,400 41,600 250 1 000 630,000 847,000 870,700 Annual Energy Demand Growth 1./ Rate (%) 7.8 4.0 3.0 2.5 2.5 Peak Load Demand Factor (kW) • 44 93 .50 118 • 50 144 . 50 193 .50 199 1/ The Community Profile indicates that there are 93 residences in Old Harbor. The figure of 7:, residential customers is taken from the AVEC Power Requirements Study; this indicates tbat in some cases more than one house is on one meter. NB !SF -389-9524-VI I-3 TABLE VI I -4 MONTHLY LOAD CHARACTER IST IcsJJ Monthly Percentage \ionthly Demand Monthly of Annual Percentage of Month (kW) (kWh) Peak Demand Annual Demand January 165 y 56,361 100.0 9.4 February 151 50,610 91.5 8.4 March 127 74,446 77.0 12.4 April 1::39 52,501 84.2 8.7 May 127 50,055 77.0 8.3 June 115 21,040 69.7 3.5 July 131 3 5' 188 79.4 5.8 August 144 44,893 87. 3 7.5 September 137 55,513 83.0 9.2 October 163 47,758 98. 8 7.9 November 163 52,465 98.8 8.7 December 163 61,648 98. 8 10.2 Based on 1979 AVEC data for Togiak. _!_/ y This value was changed from 192 kW to 165 kW because it seemed abnormally high compared to other years. This gives a 41.7 percent annual load factor. NBISF-419-9524-VII-4 TABLE VI I-5 ANNUAL HEATING DEMAND OLD HARBOR Year 1980 1985 1990 2000 2001 -- Annual Fuel Oil (BBL. )1:./ 1, 910 2, 268 2,625 3, 200 3,258 Annual Requiremen~ ( 1000 kWh) 2,973 3,530 4,086 4,981 5,071 1./ The 1980, 1990, and 2000 values were taken from the CH2M HILL report (1981). Other values were extrapolated. - 2;' Based on 55 Gal/BBL, 138,000 BTU/Gal, 70% efficiency, and 3413 BTU /kWh. NBI-419-9524-VII-5 Heating Month Degre~/ Days - January 845 February 1067 March 860 April 635 May 595 June 370 July 200 August 240 September 370 October 650 November 800 December 1200 TABLE VI I -6 MONTHLY HEATING DEMANDsl./ OLD HARBOR Percentage of Annual Heating De~ree Days 1980 1985 -----------1000 10. 80 321.2 375.9 13.62 405.1 47 4.1 1 o. 98 326.5 382.2 8. 11 241.2 282.3 7.60 226.0 264. 6 4.72 140.4 164.3 2.56 76. 1 89. 1 3.06 91.0 106.5 4.72 140.4 164. 3 8. 30 246.8 288.9 10.21 303.6 355.4 15. 32 455.6 533.3 1990 2000 2001 kWh------===--------- 441.4 538. 1 549.9 556.6 678.5 693.4 448.8 547.0 559.0 331.5 404.0 412. 8 310.6 378.6 386.9 192.9 235.2 240.3 104.6 127.5 130.3 12 5. 1 152.4 155.7 192. 9 235.2 240.3 339.2 413.5 422.6 417.3 508.7 519.8 626.1 763.2 779.9 ~/ Based on the number of heating degree days indicated in the Old Harbor Community Profile multiplied by the Annual Heating Demands from Table VII-6. ~ From the Old Harbor Community Profile. NBI-419-9524-VII-6 TABLE VII-7 ANNUAL ENERGY DEMAND OLD HARBOR Direct Total Electrical Heating Combined Demand .JJ Demand Demand --------------------1000 kWh------------------------- 1B80 355 2,973 3,328 Hl85 518 3,530 4,048 Hl90 630 4,086 4,716 2000 847 4,981 5,828 2001 871 5,071 5,942 2034 871 5,071 5,942 1} From Table VII-3. NBI-419-9524-VII-7 TABLE VII-8A 1980 MONTHLY ENERGY DEMAND OLD HARBOR Percentage of Annual Direct Direct Electrical Heat Month Demand Demand 1/ Demand 2/ -------1000 kWh --- ---- January 9.4 33.5 321.2 February 8.4 29.9 405.1 March 12.4 44.1 326.5 April 8.7 31.0 241.2 May 8.3 29.5 226.0 June 3.5 12.5 140.4 July 5.8 20.6 76.1 August 7.5 26.7 91.0 September 9.2 32.8 140.4 October 7.9 28.1 246.8 November 8.7 31.0 303.6 December 10.2 36.3 455.6 Based on Annual Direct Demand of 355,000 kWh from Table VII-3. From Table VII-7. NBI-419-9524-7-8A Total Demand --- 354.7 435.0 370.6 272.2 255.5 152.9 96.7 117.7 17 3. 2 274.9 334.6 491.9 TABLE VII-8B 1985 MONTHLY ENERGY DEMAND OLD HARBOR Percentage of Annual Direct Direct Electrical Heat Total Month Demand Demand 1./ Demand y Demand --- --1,000 kWh -------- Ja.nuary 9.4 48.7 375.9 February 8.4 43.5 474.1 Mc.rch 12.4 64.2 382.2 April 8.7 45.1 282.3 May 8.3 43.0 264.6 June 3.5 18.1 164.3 July 5.8 30.0 89.1 August 7.5 38.9 106.5 SHptember 9.2 47.7 164.3 Oetober 7.9 40.9 288.9 November 8.7 45.1 355.4 D~,~cember 10.2 52.8 533.3 l/ Based on Annual Direct Demand of 578,000 kWh from Table VII-3. -2_/ From Table VII-7. NBI-419-9524-7-8B --- 424.6 517.6 446.4 327.4 307.6 182.4 119.1 145.4 212.0 329.8 400.5 586.1 TABLE VII-8C 1990 MONTHLY ENERGY DEMAND OLD HARBOR Percentage of Annual Direct Direct Electrical Heat Total Month Demand Demand 1f Demand ~/ Demand -------------------1000 kWh ---------------------- January 9.4 59.2 441.4 February 8.4 52.9 556.6 March 12.4 78.1 448.8 April 8.7 54.8 331.5 May 8.3 52.3 310.6 June 3.5 2 2. 1 192.9 July 5.8 36.5 104.6 August 7.5 47.3 12 5. 1 September 9.2 58.0 192.9 October 7.9 49.8 339.2 November 8.7 54.8 417.3 December 10.2 64.3 626.1 l/ Based on Annual Direct Demand of 630,000 kWh from Table VII-3. 1_1 From Table VII-7. NBI-419-9524-7-8C 500.6 609.5 526.9 386.3 362.9 215.0 141. 1 172.4 250.9 389.0 472. 1 690.4 TABLE VII-8D 2001 MONTHLY ENERGY DEMAND OLD HARBOR Percentage of Annual Direct Direct Elect rica} Heat Total Month Demand Demand 1.. Demand y Demand -·--- --- ---1000 kWh ------------ January 9.4 81.8 549.9 631.7 February 8.4 73.1 693.4 766.5 March 12.4 107.9 559.0 666.9 April 8.7 75.8 412.8 488.6 May 8.3 72.3 453.2 525.5 Jtcne 3.5 30.4 240.3 270.7 July 5.8 50.5 130.3 180.8 August 7.5 65.3 155.7 221.0 September 9.2 80.1 240.3 320.4 Oetober 7.9 68.8 422.6 491.4 November 8.7 75.8 519.8 595.6 Df~cember 10.2 88.8 779.9 868.7 1} Based on Annual Direct Demand of 847,000 kWh from Table VII-3. From Table VII-7. NBI-419-9524-7-8D Direct_!_/ Electrical Demand TARLE VII-9A 1980 ENERGY GENERATION, DEMAND, AND USAGF OLD HARBOR Hydro~/ Direct Use Remaining Energy J.!ydro _.Ene rg¥_ H~dro Energ~ -----·-----.--------------------------1000 kWh------------- Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Totals 33.5 29.9 44.1 31.0 29.5 12.5 20.6 26.7 32.8 28. l 31.0 36.3 356.0 From Table VII-8A. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ilea t;..!_/ Hydro Used Demand F ------------ 321.2 0 405.1 0 326.5 0 241.2 0 226.0 0 140.4 0 76.1 0 91.0 0 140.4 0 246.8 0 303.6 0 455.6 0 2,973 0 1 '!:_/ The! proposed hydroelectric pro,iect wilt not f':O on-1 ine until late 1984 or early 1985. For purposes of the projections 1 an on line date of January 1985 has been assumed. NBISF-419-9524-7-9A Di rec.J./ Electrical Month Demand TABLE VII-9B 1985 ENERGY GENERATION, DEMAND, AND USAGE OLD HARBOR Hydra'!:../ Direct Use Remaining Energy Hy:dro Energy: Hy:dro Energy Heat-!-/ Hydro Used Demand For Heat -------------------------------------1000 kWh------------------------------------ .Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Totals 48.7 43.5 64.2 45.1 43.0 18. 1 30.0 38.9 47.7 40.9 45.1 52.8 518.0 1 From Table VII-8R ~/ See Section VI NRTSF-419-9524-7-9B 67.8 48.7 58.2 43.5 41.2 41.2 84.7 45.1 205.5 43.0 204.4 18.1 81.5 30.0 91. 1 38.9 156.8 47.7 145.1 40.9 109.2 45.1 64.6 52.8 1310.1 495.0 19. 1 375.9 19.1 14.7 474.1 14.7 0 382.2 0 39.6 282.3 39.6 162.5 264.6 162.5 186.3 164.3 164.3 51.5 89.1 51.5 52.2 106.5 52.5 109.1 164.3 109. 1 104.2 288.9 104.2 64.1 355.4 64.1 11.8 533.3 11.8 815.1 3530.0 815.1 Directl/ Elect rica] Month Demand TABLE VII-9C 1990 ENERGY GENERATION, DEMAND, AND USAGE OLD HARBOR HydroY Direct Use Remaining Energy Hydro Energl'_ H~dro Energy Heat..!_/ Demand ----------------~-------------------1000 kWh----------------------- Jan 59.2 Feb 52.9 Mar 78.1 Apr 54.8 May 52.3 June 22.1 July 36.5 Aug 47.3 Sep 58.0 Oct 49.8 Nov 54.8 Dec 64.3 Totals 630.0 1 ~I From Table VII-8C See ction V 67.8 59.2 8.6 441.4 58.2 52.9 5.3 556.6 41.2 41.2 0 448.8 84.7 54.8 29.9 331.5 205.5 52.3 153.2 310.6 204.4 22.1 182.3 192.9 81.5 36.5 45.0 104.6 91. 1 47.3 43.8 125.1 156.8 58.0 98.8 192.9 145. 1 49.8 95.3 339.2 109.2 54.8 54.4 417.3 64.6 64.3 0.3 G26.1 1310.1 593.2 716.9 4086.0 Hydro Used For Heat ---------- 8.6 5.3 0 29.9 153.2 182.3 45.0 43.8 98.8 95.3 54.4 0.3 716.9 Direct.!./ Elect rica 1 Month Demand TABLE VII-9D 2001 ENERGY GENERATION, DEMAND, AND USAGE OLD HARBOR Hydro'!) Direct Use Remaininp; Energy Hydro Energy Hydro Energy Heat.Y Hydro Used Demand For Heat ------------------------------------1000 kWh----------------------------------- Jan 81.8 Feb 73.1 Mar 108.0 Apr 75.8 May 72.3 June 30.5 July 50.5 Aug 65.3 Sep 80.1 Oct 68.8 Nov 75.8 Dec 88.8 'fotals 870.7 1 :Y From Table VII-8D See Section V NBISF-419-9524-7-9D 67.8 58.2 41.2 84.7 205.5 204.4 81.5 91.1 156.8 145.1 109.2 64.6 1310.1 ' 67.8 0 549.7 67.8 58.2 0 693.4 58.2 41.2 0 614.0 41.2 75.8 8.9 412.8 75.8 72.3 133.2 386.9 72.3 30.5 173.9 240.3 30.5 50.5 31.0 130.3 50.5 65.3 25.8 155.7 65.3 80.1 76.7 240.3 80.1 68.8 76.3 422.6 68.8 75.8 33.4 519.8 75.8 64.6 0 779.9 64.6 749.7 560.4 5071 560.4 20 \\\\\\\\\\\\\, -,o a: L&J -~ ...... 0 0 0 .. - )( s:. ~ 5 ..¥ - 0 z <t ~ L&J 0 ..J <t :J z z <t () 300 400 0 100 200 UNIT COST (MILLS I kWh) COST AND DEMAND FIGURE ELECTRICAL ENERGY IN ALASKA Jm-1 2.0 -···· 1.5 ----~-- I. 0 ~ ~' ----------------------~--------------------~-- -0 0 0 ... :TOTAL ELECTRICAL DEMAND ~·--- l( NOT INCLUDING HEATING t DEMAND) _ _ _ _ _ j ,.--------:..t.. / /OIESEL ENERGY REQUIRED TO . - MEET ENERGY DEMAND (NOT 0 o0.5; ~ . . HYDROELECTRIC ENERGY USED. . . TO MEET ENERGY DEMAND (NOT .. INCLUDING H.E.ATING DEMANOJ !NSTALLE CAPACITY: 340 kW) -- c.: l - - ~ 0 E--~---__________________ __..._ 1980 1990 2000 2010 2020 2030 YEAR DETAIL DATA I 0.0 •·--···········-······· -0 0 0 ... 0 0 0 ... - )( s::::. ~ .X - >-(!) a: UJ z LIJ ·-------- ----------·------------------~ ···-----· ----- t-----------------~. ---·---·-···--------··-----------------·-------~-----·---· ------·------------· I E~~~~=-=-----~~~~-~~~~~~-~~~Q _ _, _____ _ ! l 5.0- I r ! ~-- 1 ! t 0 L .••• 1980 YEAR 1990 ANNUAL HYDRO ENERGY GENERATION' 340 kW¥ _ . .... _ _ .. . .. . . _ .! 7 5 _kW= _______ [)IRECT_EL~GTRICAL DEMAND -----=---- (NOT INCLUDING HEATING DEMAND 2000 2010 2020 2030 OVERALL DATA OLD HARBOR HYDROELECTRIC PROJECT PROJECTED ANNUAL ENERGY GENERATION, DEMAND, AND USAGE FIGURE m-2 -0 0 0 .. > ~ L&J z L&J 220- 200 180 160 DIRECT ELECTRICAL 140 (NOT INCLUDING HEATING ~MAND) 120 100 ""' 80 20 0 J REQUIRED DIESEL GENERATION F M A MONTH HYDROELECTRIC ENERGY AVAILABLE TO MEET HEATING DEMAND HYDROELECTRIC POTENTIAL J J AS 0 N D DETAIL DATA - 1000 --- 900· f\ . -~ \ 8oo ---~~ ~ //'"\~TOTAL COMBINED DEMAND ./ 700 '\ I \ I ,, ~ \ I I 6oo \ /"' \ I I \ \ \ I If\. \j ' \ 200 I" I I I \ soo \ /', \ '..j I 1 1 \1 \ \ 19JO\ I // I 4oo \\ \ II I \' \ I / 0 300 0 \.1985_~ \ I I / ---~\ II \\\ / 1/ 0 .. ~ \ I // TOTAL JC ---=-' / / ELECTRICAL .c: 200 HYDROELECTRIC -' / '/_ DEMAND) ~ POTENTIAL _, / ~ / 2001)1: > 100_ /""""', -:.;:~ - C) ---"' ~........ -....... ...,.,. ...,.,. ..,.. 0::: -_.....---'-.,.,. --L&J ----......... -~ ,_ "!'!!""".-.::::.---::tiJj.-....... -:;..-=:::.--z ~-1985_/ L&J 0 J F M AM J J AS 0 N 0 MONTH OVERALL DATA OLD HARBOR HYDROELECTRIC PROJECT PROJECTED MONTHLY ENERGY GENERATION, DEMAND, AND USAGE FIGURE lll[-3 SECTION VI II PROJECT COSTS A. GENERAL The basic assumptions and methodology used to analyze the total project cost of the Old Harbor Hydroelectric Project and a summarized cost estimate are presented in this section. A more detailed breakdown of the cost estimate methodology is contained in Appendix D, Detailed Cost Estimate. The appendix contains the backup data, including the project construction schedule and manpower projection. B. COST ESTIMATING BASIS Several alternative methods of preparing cost estimates were considered. The heavy construction estimating method was determined to be more realistic in this case because of the nature and location of the project. The approach taken to prepare the construction cost estimate was to determine the cost of the required permanent materials and equipment, construction equipment, and labor. Due to the location of the project site, it was determined that all material and equipment would be transported by barge. For the purposes of this estimate, the material prices at Seattle, Washington, were determined. Shipping costs by barge from Seattle to Old Harbor were used. Material prices were based on estimating quotes by various manufacturers; commercial barge transportation companies, based at Seattle, provided shipping rate quotations for the appropriate commodity classifications. The skilled labor force was assumed to be brought in by the contractor. Current wages, based on union scale, including NBI-419-9524-VIII VI Il-l benefits and premium rates for overtime were used. The con- struction personnel will be housed in a construction camp set up specifically for this project. Commercial firms that pro- vide these services in Alaska were contacted for quotes on the cost of this service. The costs used are based on a cost per person-day. They are January 1982 prices that include setup and demobilization. Alaskan contractors were contacted for construction equip- ment costs, which are current costs based on ownership, opera- tion, and maintenance. This estimate also assumes that the equipment will be barged in from Seattle. As support to the project, commercial air charter firms provided current costs for various sized airplanes suitable for transporting personnel and supplies. A construction schedule was prepared to allocate manpower, material, and equipment costs to each major construction cate- gory. Allowances were made for associated miscellaneous activities required for completion of each item. The direct construction cost was determined from the various costs men- tioned above. Along with the various backup information, these costs are presented in the Summary of Costs, Table D-6 of Appendix D. C. BASE CASE PLAN Detailed costs were not estimated for the base case plan because that degree of refinement was not necessary. Costs of major items are presented in Section IX, Economic Analysis. D. RECOMMENDED PROJECT COSTS A rigorous method of cost estimating, known as the heavy- construction estimating method, was employed to define all NBI-419-9524-VIII VIII-2 project tasks and then determine the time, materials, quanti- ties, equipment, and skilled personnel required for each task. Using up-to-date Alaskan data for skilled craft wages, equipment ownership and use rates, and material and machinery costs FOB Seattle, the major direct costs for the project -- project mobilization and transportation of materials, equipment and labor, permanent material, and construction camp costs -- were determined. The remote nature of the site will require that construc- tion materials and equipment be barged from Seattle at the outset and be returned to Seattle by the same means after proj.ect completion. Barge costs are based on weight and type of commodity. Personnel and supplies will be transported by air. It was assumed that the crew will be housed in a catered construction camp for the duration of the project. Camp costs were based on a fixed unit cost per man-day of accommodation. The camp will be large enough to accommodate necessary fluctua- tions in the size of the work force. Subcontracted items included in the estimate are for con- struction of the transmission line, moving the turbine/ generator assembly into place in the powerhouse, and erection of the prefabricated powerhouse superstructure. A 15 percent contingency factor was applied to direct construction costs, including the subcontractors, except for the transmission line subcontract, which includes a 10 percent contingency. A 10 percent markup by the prime contractor for handling and over- head was applied to the transmission line subcontract and was applied to all construction costs except the transmission line subcontract. The prime contractor's profit was assumed to be 15 percent. Engineers' fees for surveying, right-of-way, geo- logy, design, and construction management were included. The NBI-419-9524-VIII VIII-3 legal and administrative costs borne by APA were set at three percent of the direct plus indirect costs. Total capital cost of the Old Harbor Hydroelectric Project is estimated to be $3,082,300 at January 1982 prices. Prices for the major components of the construction work and the in- direct costs are presented in Table VIII-1. NBI-419-9524-VIII VIII-4 Item Mobilization and Demob. Diversion Dam Steel Structures Concrete Reinforcement Intake Offtake Structure Sediment Structure Concrete Reinforcement Penstock Steel 24 inch dia. TABLE VI II-1 OLD HARBOR CONSTRUCTION COST Quantity Unit LS 1,120 LB 10 CY 1,133 LB 3,500 LB 8,000 LB 9 CY 1,035 LB 1,000 LF Fiberglass 24 inch dia. 1,200 LF Concrete Pads 8 CY Excavation 1,050 CY Backfill 945 CY Powerhouse Prefab Building LS Turbine and Generator LS Auxiliary Systems LS Concrete 98 CY Reinforcing Steel 11,105 LB Access Road Excavation, Common 8,400 CY Backfill 987 CY Culvert 100 LF Excavation, Rock 7,500 CY Construct Dock LS NBI-419-9524-8-1 Unit Price Amount ($) ($) $275,230 3.58 4,010 1254 12,540 1. 73 1,950 $ 18,500 3.58 12,540 3.58 28,620 1251 11,260 1. 73 1,780 $ 54,200 98 98,180 93 111,190 1449 11,590 17 18,110 9 8,690 $247,760 46,560 352,270 116 '330 1254 122,840 1. 73 19,160 ~657,160 17 146,450 23 22,750 64 6,420 29 218,430 $349,050 $18,430 Transmission Line (Subcontract) Contingencies -15% TABLE VIII-1 (Concluded) (Excluding Subcontract Portion) of Transmission Line) Contract Cost Engineering Right-of-Way and Geology Design Construction Management Owner's Legal and Administrative TOTAL PROJECT COST * January 1982. NBI-419-9524-8-1 Amount $ 632,500 262,180 $2,642,500 $ 50,000 175,000 125,000 89,800 $3,082,300 * SECTION IX ECONOMIC ANALYSIS A. GENERAL The economic parameters and methodology used to analyze the economic feasibility of the Old Harbor Power Project and the results of the analysis are presented in this section. The methodology and criteria used for this analysis are in accordance with the standards set forth by APA. The present worth of the total costs of the base case as developed in Section VII is compared to the present worth of the total costs of the proposed hydroelectric project in order to determine the more advantageous scheme for development. Based on this analysis, the proposed hydroelectric project is the more favorable alternative and it appears to be feasible. B. PROJECT ANALYSIS PARAMETERS The assumptions that form the basis for this analysis are founded to as great an extent as possible on the APA standard criteria. Wherever necessary, additional assumptions were based on the best available information and on experience. The data previously developed in Section VII, Project Energy Planning, and Section VIII, Project Costs, are used extensively in this analysis. The planning period and the economic evaluation period both begin with January 1982. The hydroelectric project is assumed to be on-line by January 1985, and the analysis extends 50 years beyond this time. Thus the last year of the analysis is 2034 and the length of the evaluation period is 53 years. The NBI-389-9524-IX IX-1 planning period for meeting future demands assumes a leveling of growth in 20 years, and it includes the year 2001. For purposes of this analysis, a no-inflation environment was assumed. The values of diesel fuel and l ubr ica t ing oil were escalated at 2.6 percent annually to account for the escalation of oil prices at a rate greater than inflation. The values were escalated for the duration of the planning period, with the last escalation occurring in the year 2001. The costs were held constant at the 2001 value for the remainder of the period of economic evaluation through 2034. The interest rate for all amortization and sinking funds was assumed to be three percent. This and the above assump- tions are in accordance with the APA criteria. Annual cash flows were discounted to January 1982 at three percent interest. The discount rate for assumed to be three percent. to January 1982. the present worth analysis was All annual costs were discounted The economic life of the hydroelectric project was assumed to be 50 years. The economic project life for diesels was assumed to be 20 years for the base case and 30 years for the hydroelectric alternative; the diesels were given a longer life for the hydroelectric alternative because they would operate significantly less than they would for the base case. Operation and maintenance costs were assigned to the year during which they would occur. Capital costs were assigned to the year in which they would occur. They were assumed to be equal to the total investment cost because the construction periods for all items included in the analysis were less than one year. Thus no interest during NBI-389-9524-IX IX-2 construction was included. The first amortization payment was shown in the year following the capital cost. Amortization costs, operation and maintenance costs, and benefits were assumed to occur at the end of the year and were shown in the year that they actually occurred. Replacement costs were handled by the use of a sinking fund. Replacement sinking funds were assumed to occur in perpetuity. All costs that were common to both plans, such as local distribution costs, were excluded. Waste heat recovery is not practical at this site due to a lack of significant heating loads in the proximity of the powerhouse. The benefit for space heating for the hydro- electric alternative was treated separately and applied as a reduction in cost C. BASE CASE ECONOMIC ANALYSIS The base case plan was analyzed to determine the present worth of the total cost of the base case plan over the entire period of analysis. The cost of the base case plan would be the sum of the costs of replacing and expanding the existing diesel generation system, insurance, operation and maintenance, lubrication oil, and fuel oil. These costs were all assigned to the year of their occurrence, and the total annual cost of the existing system was calculated for each year of the period of economic evaluation. These annual costs were then discounted at three percent interest to January 1982. They were then summed to find the total present worth of the base case alternative. NBI-389-9524-IX IX-3 The costs of replacing and expanding the existing diesel plant consist of adding an additional 150 kW unit to the plant in 10 years, at a cost of $200,000, and replacing the remainder of the plant in 20 years, at a cost of $600,000. The plant would be replaced every 20 years thereafter at a cost of $800,000. The existing 155 kW engines would be replaced with 200 kW engines at the 20-year replacement. The replacement cost was assumed as $500,000 for the first ten years; $700,000 for years 11 through 20; and $800,000 thereafter. The cost of insuring the power plant was assumed to be $0.83 per $100 of replacement value. This rate represents current insurance rates for Alaska. The existing plant was assumed to have a replacement value of $500,000 and it was treated as a sunk cost in both cases. If it were desired to develop average unit costs representative of total costs in earlier years, an assumption with regard to expenditures needed to meet other fixed charges on the existing plant would need to be made. The costs of operation and maintenance reflect experience and they were assumed to be the sum of the maintenance cost, calculated as $17 per megawatt-hour of energy produced, and the cost of an operator, which was taken as $60,000 per year. The total cost of lubrication oil was calculated from the unit cost of lubrication oil and the amount of lubrication oil required. The lubrication oil rate of use was assumed to be 0.60 gallons per megawatt-hour and the cost of lubrication oil was assumed to be $3.95 per gallon for January 1982. The cost of lubrication oil was also escalated at 2.6 percent for the duration of the planning period to be consistent with treatment of all petroleum products. The total cost of fuel oil was calculated from the cost per gallon of fuel oil and the anticipated rate of fuel oil con- NBI-389-9524-IX IX-4 sumption. The average energy value of fuel oil was taken as 138,000 Btu/ gallon and the average overall efficiency of the diesel generators was assumed to be 22 percent; using these criteria, one gallon of oil will produce 9.0 kilowatt-hours of electricity. The fuel oil cost for Old Harbor was established at $1.70 per gallon for January 1982 and escalated according to the previously mentioned criteria for real price changes. The annual costs over the project economic study period of the base case diesel generation for operations and maintenance, lubrication oil, and fuel oil are presented in Tables IX-1, IX- 2 and IX-3, respectively, and combined in Table IX-4 to show the annual cost for the base case for each year of economic evaluation. The annual base case diesel generation costs and present worth of these costs are presented in Table IX-5. As shown, the total January 1982 present worth of the costs of the base case would be $8,183,433. D. RECOMMENDED HYDROELECTRIC PROJECT ECONOMIC ANALYSIS The recommended hydroelectric project plan was analyzed to determine the present worth of the total cost of the recom- mended project over the period of economic evaluation. The cost of the recommended project would include the costs of building, replacing, operating and maintaining the new hydro- electric development and the costs associated with replacing and expanding the existing diesel system, insurance, operation and maintenance, lubrication oil, and fuel oil for the diesel system. It would be necessary to maintain sufficient diesel capacity to meet projected power demands in the event of an outage of the hydroelectric plant. This has been previously discussed in Section VII and it is illustrated in Table IX-9. The diesel capacity would also be required at times when the NBI-389-9524-IX IX-5 demand on the system is greater than can be met by the hydroelectric generation. The cost of the diesel supplement to hydroelectric genera- tion was calculated in the same manner as for the base case, with the following differences: the diesels supplied only the demand that could not be met by the hydroelectric plant; the plant would be replaced after 30 years instead of 20 years; and only one-half of the operator's salary would be assigned to the cost of the diesel, the other half being assigned to the hydro- electric project. The annual costs over the project economic study period of the supplemental diesel system for the recommended hydro- electric project for operation and maintenance, lubrication oil and fuel oil are presented in Tables IX-6, IX-7, IX-8, respec- tively. Those costs are combined in Table IX-9 to present the annual cost for the supplemental diesel generation for each year of the economic evaluation. The capital cost of $3,082,300 for the hydroelectric power plant was amortized at three percent over a period of 50 years from the on-line date of the power project. The cost of the operation and maintenance was taken as 1.5 percent of the direct construction cost plus contingencies; this is based on U.S. Bureau of Reclamation practice. Two replacement costs were considered for the hydroelectric power plant: the cost of replacing the turbine runner after 25 years of operation, and the cost of replacing the transmission line that would tie the plant to the village distribution system every 30 years. The cost of replacing the runner was estimated as $55,000, and the cost of replacing the lines was estimated as $632,500. Sinking funds were established to meet these costs. NBI-389-9524-IX IX-6 The annual costs of the hydroelectric portion of the recommended hydroelectric project are presented in Table IX-10. This table includes the amortization, operation and main- tenance, and replacement costs. These costs are then combined with the annual costs for the supplemental diesel system from Table IX-9 and presented as the combined diesel and hydro- electric costs in Table IX-11. The proposed hydroelectric power plant would also generate power in excess of the village's direct demand during certain times of the year. The hydroelectric energy that would be available in excess of the village's direct electrical demand could be used to replace generation at the cannery. Any excess hydroelectric energy could be used for space heating in the village. The distribution of hydroelectric generation is addressed in Chapter VII. The space heating energy available from hydroelectric generation would be equivalent to one gallon of oil for every 29 kilowatt-hours of available electricity. The values used are from Tables Vll-9A to VII-9D. The cost of installing electric space heaters was estimated at $40 for a 500-watt heater, installed. The annual savings for the hydroelectric energy used for space heating are presented in Table IX-12. This table indicates the annual hydroelectric energy available for the heat demand, the equivalent amount and cost of the fuel oil displaced, annual cost of the electric space heating, and the resulting net annual savings. The present worth of the recommended hydroelectric project cost is presented in the Table IX-13 summary as $6,397,361. This table also shows that the present worth of the savings in fuel from the hydroelectric energy used to meet space heating demand would be $1,239,000. NBI-389-9524-IX IX-7 E. ECONOMIC COMPARISON OF PROJECTS The economic comparison of the base case plan and the recommended hydroelectric project can be analyzed in two different ways. The first is a comparison of the present worth costs of each plan and the second is a comparison of the recom- mended hydroelectric costs only with net avoided costs (bene- fits) measured as the costs of the diesel alternative adjusted for the diesel costs associated with the hydroelectric proj- ect. This is similar to the conventional B/C ratio, which identifies only the water project investment on the cost side of the equation and compares these costs to the net beneficial effects. 1. Comparison of Present Worth Costs This method of comparison is the one specified by the Alaska Power Authority. The comparison is summarized in Table IX-14. As shown, the present worth of the base case costs is $8,183,433. The gross present worth of the recommended hydroelectric project before credit for supplying electricity for space heating is $6,397, 361. Subtracting the present worth of the savings in space heating and cannery credits of $1,239,000 then yields a net present worth of the recommended hydroelectric project of $5,158,361. 2. Comparison of Net Avoided Costs (Benefits) and Hydroelectric Project Costs The conventional benefit/cost ratio normally compares the water project costs only with the most likely thermal alterna- tive. The values are adjusted so that the outputs are compar- able. Nonhydroelectric project costs associated with the hydroelectric plant, for example standby diesel costs, would NBI-389-9524-IX IX-8 represent a reduction in avoided costs, or benefits, attribut- able to the hydroelectric project. Derivation of benefit/cost ratios to reflect the various levels of demand, including savings in space heating, are summarized on Table IX-15. The benefit/cost ratio for the recommended hydroelectric project is 1.44 when the direct electrical needs only are considered and 1. 74 when the space heating benefits are also included. NBI-389-9524-IX IX-9 TABLE IX-1 BASE CASE DIESEL OPERATION AND MAINTENANCE COSTS OLD HARBOR Year 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002- 2034 Annual Energy 1./ Production (1000 kWh) 420.8 453.2 485.6 518.0 540.4 562.8 585.2 607 0 6 630.0 651.7 673.4 695.1 716.8 738.5 760.2 781.9 803.6 825.3 847.0 870.7 870.7 ll From Table VII-3. Maintenance ~I ($) 7' 153 7,704 8,255 8,810 9,200 9, 570 9,950 1 o, 330 10,710 11' 080 11,450 11' 820 12,180 12' 550 12,920 13' 290 13,660 14,030 14,400 14,800 14,800 ~I $17 per megawatt-hour. ~I Salary for one operator NBI-389-9524-IX-1 Operation ~I ($) 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 60,000 60' 000 Annual Cost ($) 67,150 6 7' 700 68,250 68,800 69,200 69,570 69,950 70,330 70' 710 71 '0 80 71,450 71,820 72' 180 72,550 72' 920 73,290 73' 660 74,030 74' 400 74,800 74' 800 TABLE IX-2 BASE CASE DIESEL LUBRICATION OIL COSTS OLD HARBOR Annual JJ Lubrication ~/ Energy Lubrication Production Oil Oil Cost Year (1000 kWh) (gallons) US/gallon) -- 1982 420.8 252 3.95 1983 453.2 272 4.05 1984 485.6 291 4.16 1985 518.0 311 4.27 1986 540.4 324 4. 38 1987 562.8 338 4.49 1988 585.2 351 4.61 1989 607.6 365 4.73 1990 630.0 378 4.85 1991 651. 7 391 4. 98 1992 673.4 404 5.11 1993 695. 1 417 5.24 1994 716.8 430 5.37 1995 738.5 443 5.51 1996 760.2 456 5.66 1997 781.9 469 5.81 1998 803.6 482 5.96 1999 825.3 495 6. 11 2000 847.0 510 6.27 2001 870.7 522 6.43 2002- 2034 1 ~I 870.7 522 From Table VII-3. 0.6 gallons per megawatt-hour. NBI-389-9524-IX-2 6.43 Luhr ication Oil Cost ($) 1,000 1,100 1,210 1,330 1, 420 1' 520 1' 620 1' 720 1, 830 1' 950 2, 060 2' 180 2,310 2, 440 2, 580 2,725 2,870 3,025 3' 190 3,360 3' 360 TABLE IX-3 BASE CASE DIESEL FUEL OIL COSTS OLD HARBOR Annual 1.! Energy Equivalent 1) Fuel Fuel Production Oil Oil Cost Oil Cost Year (1000 kWh) (gallons) ($/~allon) ($) 1982 420.8 46,750 1. 70 79,475 1983 453.2 50,350 1. 74 87,610 1984 485.6 53,950 1. 79 96,570 1985 518.0 57,550 1.84 105,890 1986 540.4 60,040 1.88 112,870 ·-1987 562.8 62,530 1.93 120,680 1988 585.2 65,020 1.98 128,730 1989 607.6 67,500 2.03 137,030 1990 630.0 60,990 2.09 146,285 ... 1991 651.7 72,400 2.14 154,940 1992 673.4 74,810 2.20 164,590 1993 695.1 77,220 2.25 173,760 1994 716.8 79,640 2.31 183,960 1995 738.5 82,050 2.37 194,250 1996 760.2 84,460 2.44 206,080 1997 781.9 86,870 2.50 217,170 ·-1998 803.6 89,280 2.56 228,560 1999 825.3 91,690 2.63 241,150 2000 847.0 94,100 2.70 254,080 2001 870.7 96,730 2.77 267,950 2002-·-2034 870.7 96,730 2.77 267,950 1.! From Table VII-3. 1./ 111.1 gallons per megawatt-hour. NBI-389-9524-IX-3 TARLE IK-4 BASE CASE OI ESEL COSTS OLD flARROR Operation Firm Schedule of Replacement Insurance .. !./ and Lubrication Fuel Capacity Investments Amortization Maintenance Oil Oil Cost Year ~->-($) ($) ($) ($) ($) ($) 1982 155 4, 150 67,150 1,000 79,475 1983 155 4,150 67' 700 1' 100 87,610 1984 155 4,150 68,250 1, 210 96. 570 1985 155 4,150 68,800 1,330 105,890 1986 155 4,150 69,200 1' 420 112, 870 1987 155 4,150 69,570 1,520 120,680 1988 155 4,150 69,950 1, 620 128,730 1989 155 4,150 70,330 1,720 137,030 1990 155 2oo:oooY 4, 150 70,710 1' 830 146,285 1991 155 4,150 71,080 1,950 154,940 1992 305 13,400 5,810 71' 450 2,060 164,590 1993 305 13,400 5,810 71' 820 2,180 173,760 1994 305 13,400 5,810 72' 180 2,310 183' 960 1995 305 13,400 5,810 72,550 2,440 194,250 1996 305 13,400 5,810 73,920 2,580 206,080 1997 305 l3' 400 5,810 73,290 2,725 217,170 1998 305 13,400 5,810 73' 660 2,870 228,560 1999 305 13' 400 5,810 74,030 3,025 241,150 2000 305 13,400 5,810 74,400 3,190 254,080 2001 350 600,000..;!__/ 13,400 5,810 74,800 3,360 267,950 2002-11 350 80o,ooo .. Y 53,770 6, 640 74,800 3,360 267,950 2012-21 350 40,330 6,640 74,800 3,360 267,950 2022-34 350 53,770 6,640 74' 800 3,360 267' 950 1 I 2/ 3/ 41 Replaeement value is $500,000 throug-h 1991; $700,000 throujl;h ?.001; and $800,000 thereafter. Adct 150 kW unit. Replace existing 150 kW units with 200 kW units. ¥Rep] n?'<'~ ent; ~~ ,rlapt i ·!i\ 20?1 Annual Diesel Cost 151,775 160,560 170, 180 180,170 187. 640 195,920 204' 450 213,230 222,980 232,120 257,310 266,970 277' 660 288,450 301,790 312,395 324' 300 337,415 350,880 365,320 406,520 393,080 406,520 TABLE IX-5 BASE CASE PLAN SUMMARY OLD HARBOR Annuall/ AnnualY Present.:?/ Energy Diesel Demand Cost Worth Year (1 000 kWh) ($) ($) 1982 420.8 151,775 147' 354 1983 453.2 160,560 151,343 1984 485.6 170,180 155,739 1985 518.0 180,170 160,079 1986 540.4 187,640 161,860 1987 562. 8 195,920 164,080 1988 585.2 204,450 166,237 1989 607.6 213,230 168,326 1990 630.0 222,980 170,896 1991 651.7 232,120 172,719 1992 673.4 257,310 185,886 1993 695.1 266,970 187,247 1994 716.8 277,660 189,073 ""~ 1995 738.5 288,450 190,699 1996 760.2 301,790 193,708 1997 781.9 312,395 194' 674 1998 803.6 324,300 196,207 1999 825.3 337,415 198' 196 2000 847.0 350,880 200,102 2001 870.7 365,320 202,269 2002-11 870.7 406' 520 1,919,980 2012-21 870.7 393,080 1,381,413 2022-34 870.7 406,520 1,325,345 TOTAL 8,183,433 ll Table VII-3 ~I Table IX-4 ~I January 1982 NBI-389-9524-IX-5 TABLE IX-6 RECOMMENDED H YDROELECT IC PROJECT DIESEL OPERATION AND ~AINTENANCE COSTS OLD HARBOR Annual JJ Energy Maintenanc~ Operatior2/ Annual Production Cost Year (1000 kWh) ($) ($) ($) 1982 420.8 7,154 30,000 3 7' 154 1983 453.2 7,704 30,000 37' 704 1984 485.6 8,255 30,000 38,255 1985 23.0 391 30,000 30,391 1986 25.8 439 3 0' 000 30,439 1987 28.5 485 30,000 30,485 1988 31.3 532 30,000 30, 532 1989 34. 0 578 30,000 30,578 1990 36.8 626 3 0' 000 30,626 1991 44.2 751 30,000 30' 751 1992 51.5 876 3 0' 000 30,876 1993 58.9 1,001 30,000 31' 001 1994 66.3 1' 127 30,000 31,127 1995 73.6 1' 251 30,000 31,251 1996 81.0 1, 377 30,000 31' 377 1997 88.4 1,503 30,000 31,S03 1998 95.8 1, 629 30,000 31' 629 1999 103. 1 1' 753 30,000 31' 753 2000 110.5 1, 879 30,000 31' 879 2001 121. 0 2,057 30,000 32,057 2002- 2034 121. 0 2,057 30,000 32,057 lJ From Table VII-9. Difference between direct electrical demand and hydro used for direct demand. ~I $17 per megawatt-hour. ~I One-half of operator's salary. NBI-389-9524-IX-6 ,_, ·- Year 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002- 2034 TABLE IX-7 RECOMMENDED HYDROELECTRIC PROJECT DIESEL LUBRICATION OIL COSTS OLD HARBOR Annual 1.1 Energy Lubrication y Lubrication Production Oil Oil Cost (1000 kWh) (gallons) ($/gallon) 420.8 252 3.95 453.2 272 4.05 485.6 291 4.16 23.0 14 4.27 25.8 15 4.38 28.5 17 4.49 31.3 19 4.61 34.0 20 4.73 36.8 22 4.85 44.2 27 4.98 57.5 31 5.11 58.9 35 5.24 66.3 40 5.37 73.6 44 5.51 81.0 49 5.66 88.4 53 5.81 95.8 57 5.96 103.1 62 6.11 110.5 66 6.27 121.0 73 6.43 121.0 73 6.43 Lubrication Oil Cost ($) 997 1,101 1,212 59 68 77 87 96 107 132 158 185 214 243 275 308 343 378 416 467 467 1} From Table VII-9. Difference between direct electrical demand and hydropower used for direct demand. y 0.6 gallons per megawatt-hour NBI-389-9524-IX-7 TABLE IX-8 RECOMMENDED HYDROELECTRIC P~OJECT DIESEL FUEL OIL COST Annual 1/ Energy- Production Year (1000 kWh) 1982 420.8 1983 453.2 1984 485.6 1985 23.0 1986 25.8 1987 28.5 1998 31.3 1989 34.0 1990 36.8 1991 44.2 1992 51.5 1993 58.9 1994 66.3 1995 73.6 1996 81.0 1997 88.4 1998 95.8 1999 103. 1 2000 110.5 2001 121.0 2002- 2034 121.0 OLD HARBOR Equivalent 2/ Oil - (gallons) 46,756 50,356 539,56 2,556 2,867 3' 167 3,478 3,778 4,089 4,911 4,722 6,544 7,367 8,178 9,000 9,822 10,644 11 '456 12,278 13,444 13,444 Fuel Oil Cost ($/gallon) 1. 70 1. 74 1. 79 1.84 1.88 1.93 1.98 2.03 2.09 2.14 2.20 2.45 2.31 2.37 2.44 2.50 2.56 2.63 2.70 2.77 2.77 Fuel Oil Cost ($) 79,476 87,610 96,571 4,702 5,389 6,111 6,885 7,668 8,545 10,509 12,588 14,724 17,015 19,379 21,958 24,553 27,247 30,125 33,147 37,237 37,~37 lJ From Table VII-3; difference between direct electrical demand and hydropower used for direct demand. 2/ 111.1 gallons per megawatt-hour. NBI-389-9524-IX-8 TABLE lX-9 RECOMMENDED HYDROELECTRIC PROJECT DIESEL COSTS OLD HARBOR Operation Firm Schedule of Annual Insurance~/ and Lubrication Fuel Annual Diesel Capacity Investment Cost Maintenance Oil Oil Cost Year (kW) ($) ($) ($) ($) ($) J.!L ($) 1982 155 4,150 37' 154 997 79,476 121,777 1983 155 4,150 37,704 1, 101 87,610 130,565 1984 155 4,150 38,255 1, 212 00,571 140, 188 1985 155 4,150 30,391 59 4,702 39,302 1986 155 4,150 30,439 68 5,389 40,046 1987 155 4,150 30,485 77 6,111 40,823 1988 155 4,150 30,532 87 6,885 41' 654 1989 155 4,150 30,578 96 7,668 42,492 1990 155 $200,000!/ 4,150 30,626 107 8, 545 43,428 1991 155 4,150 30,751 132 10,509 45,542 1992 305 13,440 5,810 30,876 158 12,588 62.872 1993 305 13,440 5,810 31' 001 185 14,724 65,160 1994 305 13,440 5,810 31,127 214 17,015 67,606 1995 305 13,440 5,810 31,251 243 19,379 70,123 1996 305 13,440 5,810 31,377 275 21, 958 72,860 1997 305 13,440 5,810 31,503 308 24,553 75,614 1998 305 13,440 5,810 31,629 343 27,247 78,469 1999 305 13,440 5,810 31' 753 378 30, 125 81,506 2000 305 13,440 5,810 31,879 416 33,147 84,692 2001 305 13,440 5,810 32,057 467 37,237 89,011 2002 305 13,440 5,810 32,057 467 37,237 89,011 2003 305 13,440 5,810 32,057 467 37,237 89,011 2004 305 13,440 5,810 32,057 467 37,237 89,011 2005 305 13,440 5,810 32,057 467 37' 237 89,011 2006 305 13,440 5,810 32,057 467 37,237 89,011 2007 305 13,440 5,810 32,057 467 37,237 89,011 2008 305 13,440 5,810 32,057 467 37,237 89,011 2009 305 13,440 5,810 32,057 467 37,237 89,011 2010 305 800,oor&' 13,440 5,810 32,057 467 37,237 89,011 2011 305 13,440 5,810 32,057 467 37,237 89,011 2012-34 350 40,800 6, 640 32,057 467 37,237 117.201 1/ Add 150 kW unit. 2/ Replace entire plant. F.xpand capacity to 350 kW. II Replacement value $500,000 through 1991; $700,000 through 2011; and $800,000 thereafter. NBI-389-9524-IX-9 TABLE IX-10 RECOMMENDED HYDROELECTRIC PROJECT HYDROELECTRIC COSTS OLD HARBOR Operation Replacement 2:._/ Replacement Capital and Schedule of Sinking Costs Amortiza tionl./ Maintenance Investment H'und Year ($) ($) ($) ($) ($) 1982 0 0 1983 0 0 1984 3,082,300 0 0 1985 119, 901 39,638 14,790 1986 119, 901 39, 638 14,790 1987 119,901 39,638 14,790 1988 119,901 39,638 14,790 1989 119, 901 39,638 14,790 1990 119,901 39,638 14,790 1991 119,901 39,638 14,790 1992 119, 901 39,638 14, 790 1993 119,901 39, 638 14,790 1994 119,901 39,638 14,790 1995 119,901 39,638 14,790 1996 119,901 39,638 14,790 1997 119,901 39,638 14,790 1998 119,901 39,638 14,790 1999 119,901 39,638 14,790 2000 119,901 39,638 14,790 2001 119, 901 39,638 14,790 2002 119, 901 39,638 14,790 2003 119,901 39,638 14,790 2004 119,901 39,638 14, 790 2005 119, 901 39,638 14,790 2006 119,901 39,638 14,790 2007 119,901 39,638 14,790 2008 119,901 39,638 14,790 2009 119,901 39,638 55,000 14,790 2010 119, 901 39,638 14,790 2011 119,901 39,638 14,790 2012- 2034 119, 901 39,638 632,500 14,790 l/ 50 years at three percent. 2:._/ R 1 ep ace turbine runner in 2009; replace transmission lines in 2014. NBI-389-9524-IX-10 Annual Hydrc,1,. Cost ($) c ( 0 174, 32~ 174,32~ 174, 32~ 174,329 17 4, 32( 174' 32~ 174,329 174' 32~· 174,32~ 174,328 174, 329,... 174' 32~ 174,32~ 174' 329 174, 32~" 174,32~ 174,329 174' 32~" 17 4, 32~ 174,32S 174,329 174' 32~""- 174, 32t 174,329 174,32~ 174,32f 174,328 174,32 TABLE IX-11 RECOMM~NDED HYDROELECTRIC PROJEC'l' SUMMARY OLD HARBOR Annuall/ Annuali./ AnnuallY Total -----G2?eration Mix-----/ Hydro Diesel Annual Demand Hydr~ Diesel~ Cost Cost Cost ~ (1000 kWh) (1000 kWh) (1000 kWh) ($) ($) ($) 1982 420.8 0 420.8 174,329 121,777 121,777 1983 453.2 0 453.2 174,329 130,565 130,565 1984 485.6 0 485.6 174,329 140,188 140,188 1985 518.0 495.0 23.0 174,329 39,302 213,631 1986 540.4 574.6 25.8 174,329 40,046 214,375 1987 562.8 534.3 28.5 174,329 40,823 215,152 1988 585.2 553.9 31.3 174,329 41,654 215,983 1989 607.6 573.6 34.0 174,329 42,492 216,821 1990 630.0 593,2 36.8 174,329 43,428 217' 757 1991 651.7 607.5 44.2 174,3?.9 45,542 219,871 1992 673.4 621.9 57.5 174,329 62,872 237,201 1993 695.1 636.2 58.9 174,329 65,160 239,489 1994 716.8 650.5 66.3 174,329 67' 606 241 '935 1995 738.5 664.9 73.6 174,329 70,123 244,452 1996 760.2 679.2 81.0 174,329 72,860 247,189 1997 781.9 693.5 88.4 174,329 75,614 249,943 1998 803.6 701.8 95.8 174,329 78,469 252,789 1999 825.3 122.2 103. 1 174,329 81,506 255,835 2000 847.0 736.5 110.5 174' 329 84.692 259,021 2001 870.7 749.7 121.0 174,329 89,011 263,340 2002 870.7 749.7 121.0 174,329 891011 263,340 2003 870.7 149.1 121.0 174,329 89,011 263,340 2004 870.7 749.7 121.0 174,329 89,011 263,340 2005 870.7 749.7 121.0 174,329 89,011 263,340 2006 870.7 749.7 121.0 174' 329 89,011 263,340 2007 870.7 749.7 121.0 174,329 89,011 263,340 2008 870,7 749.7 121.0 174,329 89,011 263,340 2009 870.7 749.7 121.0 174,329 89,011 263,340 2010 870.7 749.7 121.0 174,329 89,011 263,340 2011 870.7 749.7 121.0 174,329 89,011 263,340 2012-34 870.7 749.7 121.0 174,329 117' 201 291,530 1 I Table VII -9. 2/ Table VI I-9. 3/ Table VII-9. 4/ Table IX-10. §j Table IX-9. NBI-389-9524-IX-11 TABLE IX-12 RECOMMENDED HYDROELECTRIC PROJECT SPACE HEATING CREDIT OLD HARBOR Energy_!_/ Oil_y Oil Unit Schedule ofl.J Amortization.~./ Net Annual Equivalent Cost Credit Investment Savings Year (100 kWh) (gal) ($/gal) ($) ($) ($) ($) 1982 0 0 1. 70 0 0 1983 0 0 1. 74 0 0 1984 0 0 1. 79 0 7,500 0 1985 815.1 28,107 1.84 51,717 290 51,427 1986 795.5 27,431 1.88 51,570 290 51,280 1987 775.8 26,752 1.93 51,631 290 51,340 1988 756.2 26,076 1.98 51,630 290 51,340 1989 736.5 25,397 2.03 51,555 290 51,265 1990 716.9 24,721 2.09 51,666 290 51,376 1991 702.6 24,228 2.14 51,847 290 51,560 1992 688.2 23,731 2.20 52,208 290 51,920 1993 673.9 23,238 2.25 52,285 290 52,000 1994 659.6 22,745 2.31 52,541 290 52,250 1995 645.2 22,248 2.37 52,728 290 52,440 1996 630.9 21,755 2.44 53,083 290 52,790 1997 616.6 21,262 2.50 53,155 290 52,870 1998 602.3 20,769 2.56 53,169 290 52,880 1999 587.9 20,272 2.63 53,316 290 53,000 2000 573.6 19,779 2.70 53,404 290 53,100 2001- 2034 560.4 19,324 2.77 53,528 290 53,240 1/ 2/ 3! 4! From Table VII-9; difference between demand. total hydro generation and hydro used for direct 29 kilowatt-hours per gallon. Electric space heaters. 50 years at 3 percent. NBI-419-9524-IX-12 -- ,_, TABLE IX-13 RECOMMENDED HYDROELECTRIC Pro.iectll Cost Year ($) 1982 121,777 :1.983 130,565 1984 140,188 t985 213,631 1986 214,375 1987 215,983 :L988 215,983 t989 216,821 1990 217,757 1991 219,871 l992 237,201 1993 239,489 1994 241,935 1995 244,452 1996 247,189 1997 249,943 1998 252,789 1999 255,835 2000 259,021 2001-11 263,340 2012-34 291,530 Totals 1/ 2! 3/ Table IX-11. Table IX-12. January 1982. NBI-419-9524-IX-13 SUMMARY OLD HARBOR Present Worth Pro,i ec t Cost ($) 118,230 123,070 128,292 189,808 184,922 180' 186 175,614 171' 160 166,893 163,605 171,359 167,973 164,746 161,612 158,661 155,756 152,947 150,276 147,716 1,389,551 4,422,377 6,397,361 PROJECT Space.V Presen21 Worth Heating Heatin!l Credit Credit ($) ($) 0 0 0 0 0 0 51,427 45,690 51' 280 44,234 51,340 43,000 51' 340 41,740 51' 265 40,470 51' 376 39,375 51,560 38,360 51,920 37,500 52,000 36,470 52,250 35,580 52,440 34,670 52,790 33,880 52,870 32' 940 52,880 32,000 53,000 31,150 53,100 30,290 53,240 53,240 1,239,000 A. BASE CASE TABLE IX-14 PRESENT WORTH COSTS OLD HARBOR NET PRESENT WORTH COSTS~/ B. RECOMMENDED HYDROELECTRIC PROJECT GROSS PRESENT WORTH COSTS LESS SPACE HEATING CREDIT NET PRESENT WORTH COSTS 1! No heat recovery at Old Harbor. NBI-419-9524-IX-14 $8,183,433 6,397,361 1,239,000 5,158,361 TABLE IX-15 COMPARISON OF HYDROELECTRIC COSTS AND BENEFITS OLD HARBOR EYDROELECTRIC PROJECT COSTS Capital Costsll Present Worth of Annual O&M ~ Present Worth Annual Replacement Costs ~/ Total Present Worth NET BENEFITS ASSOCIATED WITH HYDRO PROJECT Present Worth of Diesel Base Case Adjusted for Diesel Costs Associated with Base Case Including Hydro (Hydro plus Diesel Case, Less Present Worth of Hydro Costs Only) Net Present Worth Benefits Related to Hydro Project Costs Only Net Benefits Adjusted for Savings for Space Heating BENEFIT/COST RATIOS · B/C for Hydro Only B/C Including Space Heating Savin~s 1982 present worth $ 2,820,921 933,392 348,274 $ 4,102,287 $ 8,183,433 2,295,074 $ 5,888,359 $ 7,127,359 1. 44 1. 74 1/ 2/ Capitalized 50 Years (1985-2034) at three percent interest based on 1982 present worth NBI-409-9522-IX-15 SECTION X ENVIRONMENTAL AND SOCIAL EFFECTS A. GENERAL An environmental study of the Old Harbor Hydroelectric Project vicinity was conducted to survey the resources in the area, evaluate potential effects of the project, and formulate 1neasures to avoid or ameliorate adverse effects. Field investigations were made, relevant literature was reviewed, and representatives of the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service were consul ted along with local residents and a local big-game guide. The study results indicate that the adverse environmental effects of the project will be minor due to the limited scope of project activities, the limited nature of the fishery resources in Midway Creek, and the availability of measures to mitigate the potential effects from the construction and opera- tion of the facilities. Implementation of the project should bring some socioeconomic benefits to Old Harbor. The local payroll will be expanded during construction and some employ- ment should be provided for local residents both for construc- tion and maintenance of the facilities. The project should bring cheaper electric power to the local residents and a dependable supply. Old Harbor residents are used to influxes of workers, but precautions should still be taken to ensure that the imported project work force does not disrupt the traditional life style of the community. The areas considered in the study included fisheries, wild- life, vegetation, archaeological and historic sites, visual resources, recreation, air quality, and socioeconomic impacts. Land status, hydrology, and geology are addressed . in NBI-419-9524-X X-1 Section IV, Basic Data. The detailed report on the environmen- tal studies conducted is contained in Appendix E and a summary of the study is presented in this section. B. ENVIRONMENTAL EFFECTS 1. Fisheries The Alaska Fisheries Atlas published by the Alaska Depart- ment of Fish and Game (ADF&G) indicates that Dolly Varden char are the only fish present in Midway Creek. Local residents indicated that a few pink salmon usually ascend the stream a short distance. However, the lower port ion of the stream is normally dry in the winter, so if spawning does occur not many eggs are likely to survive the winter. No fishing occurs in Midway Creek. Seven Dolly Varden and one rainbow trout were caught in minnow traps in the lower part of Midway Creek during the field survey. No pink salmon were observed. that Midway Creek is a stream with resources. All evidence indicates very limited fishery Dewatering or reducing flows in Midway Creek between the weir and the powerhouse may prevent fish from using this reach. Construction activities will also increase erosion and sedimentation temporarily. Proper construction practices should be observed even though the fishery resources are limited. The design of the diversion weir will allow it to be collapsed temporarily should it prove to be necessary to flush out the spawning gravels below the weir. 2. Wildlife Information on wildlife in the Old Harbor area was obtained primarily through correspondence with ADF&G and conversations NBI-419-9524-X X-2 with the local big game guide, Larry Matfay. Big Creek, the stream to which Midway Creek is tributary, is used heavily by bears throughout the year. Denning probably occurs in the upper reaches of Midway Creek too, and bears feed along the slopes of the Midway Creek watershed in the spring. The lower elevations of Midway Creek are good deer wintering areas. And mountain goats have extended their range into the higher eleva- tions of the Big Creek drainage. Big Creek has a good beaver population as well as land otter in the tidally influenced area. The bird population includes eagles, sharp-shinned hawks, duck, goldeneyes, harle- quins, buffleheads, scoters, eiders and oldsquaws. Mammals and birds of the Kodiak Archipelago are listed in Appendix E. No endangered species occur on Kodiak Island, according to the U.S. Fish and Wildlife Service, although the Peales peregrine falcon, a nonendangered subspecies, does nest on the island. The annual harvest of deer by Old Harbor residents probably does not exceed 150. Red fox, beaver, and land otters are also trapped by a few local residents, and the Big Creek area is commonly used for duck hunting. Project construction will result in permanent habitat loss at the diversion weir, the powerhouse site, and the access road to the site of the weir. This loss should be minor because of the limited size of the project. Operation of heavy equipment and other construction activities will create considerable noise that will disturb wildlife and cause some species to abandon their normally used areas at least temporarily. However, all construction activity should be completed in six months or less. NBI-419-9524-X X-3 During project operation, alterations in the flow regime between the diversion weir and the powerhouse may force water- dependent animals such as the water ouzel to relocate. 3. Vegetation The stream delta is covered with cottonwood, with an alder, devils club and elderberry understory. Near saltwater and along the sides of the delta, the cottonwood community grades into a grass meadow. Along the stream valley, extensive alder, elderberry and salmonberry thickets intermix with a grass meadow containing cow parsnip, f ireweed and goa tsbeard. In higher elevations, the meadow community appears to dominate. 4. Archaeologic and Historic Sites An archaeological site has been located on the delta of Midway Creek, but the extent of the site is unknown. The Division of Parks may recommend that an archaeological survey be done in the project area before construction begins. 5. Visual Resources The transmission line is expected to be the only project feature to have a visual impact. 6. Recreation Little recreational use is currently made of the Midway Creek drainage. The present plan is to gain access to the project facilities by building a dock on Midway Bay rather than by building a road to the town of Old Harbor. Thus the proJeCt should have little effect on recreation, although the short access road from the dock to the project facilities will increase the use of surrounding areas. NBI-419-9524-X X-4 7. Air Quality During project construction, exhaust fumes from diesel equipment and dust generated by construction activity may diminish air quality. However, the project is more than one mile from the North Village portion of Old Harbor; winds are common in the area and should rapidly disperse any air pollutants. Electrical power for Old Harbor is currently provided with diesel generators. hydropower should pollutants. Replacement of diesel-generated power by lower the discharge of hydrocarbon C. SOCIOECONOMIC EFFECTS No major socioeconomic impacts are anticipated during the construction period for the proposed hydropower facility. The Old Harbor population normally increases by as many as 60 people during the commercial fishing season, so locals are accustomed to influxes of people. The construction force and support personnel are not expected to exceed 21 and they will average 16. If accommodations are not available locally, as is likely, trailers can be brought in and a work camp can be set up. In the year of construction, mobilization would probably begin about April 1, with actual work beginning about April 15. The project should be completed by September 31 of the same year. Working hours would be 10 hours a day, six or seven days a week until the project is completed. Thus the workers will have little time for recreation. Skilled craft labor will be required on the project work force and the policy should be to hire local people if they have appropi ate skills. Old Harbor residents may well resent imported labor unless they are given first consideration for jobs. However, construction will occur during the summer NBI-419-9524-X X-5 months, so many residents are likely to be busy with commercial fishing and not be available for hire. Even though Old Harbor residents are used to seasonal influxes of workers, the manager of the project construe t ion team will have to take precautions to ensure that the imported workers do not disrupt the traditional life style of the community. Some foresight accommodate the imported achieving this objective. in work setting force up a trailer camp should be helpful to in If the project is implemented, the hydroelectric power should provide a cheaper electric supply to the local resi- dents. The Old Harbor community will also benefit from the enlarged payroll during construction and from the employment of some local workers both for construction and maintenance activities. NBI-419-9524-X X-6 SECTION XI PROJECT IMPLEMENTATION A. GENERAL This chapter presents comments regarding the various licenses, permits, and institutional considerations that will be encountered during the implementation phase of the Old Harbor project. A project development schedule is also presented and discussed. B. PROJECT LICENSES, PERMITS, AND INSTITUTIONAL CONSIDERATIONS The following permits may be required for construction of the Midway Creek facility: 1. Under the authority of Section 404 of the Federal Water Pollution Control Act Amendments of 1972, the Army Corps of Engineers (COE) must authorize the discharge of dredged or fill materials into navigable waters, which includes adjacent wetlands, by all individuals, organizations, and federal, state and local commercial enterprises, agencies. A COE Section 404 Permit will therefore be required for the diversion weir on Delta Creek. 2. A Water Quality Certificate from the State of Alaska, Department of Environmental Conservation (DEC), is also required for any activity that may result in a discharge into the navigable waters of Alaska. Application for the certificate is made by submitting to DEC a letter requesting the certificate, accom- panied by a copy of the permit application being submitted to the Corps of Engineers. NBI-419-9524-XI XI-1 3. All public or private entities (except federal agencies) proposing to canst ruct or operate a hydro- electric power project must have a license trom the Federal Energy Regulatory Commission (FERC) it the proposed site is located on a navigable stream, or on U.S. lands, or if the project affects a lJ.S. govern- ment dam or interstate commerce. 4. A Permit to Construct or Modify a Dam is required from the Forest, Land and Water Management Division of the Alaska Department of Natural Resources for the con- struction, enlargement, alteration or repair of any dam in the State of Alaska that is ten feet or more in height or stores 50 acre-feet or more of water. 5. A Water Rights Permit is required from the Director of the Division of Forest, Land and Water Management, Alaska Department of Natural Resources, for any person who desires to appropriate waters of the State of Alaska. However, this does not secure rign ts to tne water. When the permit holder has commenced to use the appropriated water, he should notify the director, wno will issue a Certificate of Appropriation that secures the holder's rights to the water. 6. The proposed project area is located within the coastal zone. Under the Alaska Coastal Management Act of 1977, a determination of consistency wi tr1 Alaska Coastal Management Standards must be obtained from the Division of Policy Development and Planning in the off ice of the governor. This determination would be made during the COE 404 Permit review. 7. Any party wishing to use land or facilities of any National Wildlife Refuge for purposes other than those NBI-419-9524-XI XI-2 designated by the manager-in-charge and published in the Federal Register must obtain a Special Use Permit from the U.S. Fish and Wildlife Service. This permit may authorize such activities as rights-of-way; easements for pipelines, roads, utilities, structures, and research projects; and entry for geologic recon- naissance or similar projects, filming and so forth. Note that all Wildlife Refuge Native Claims lands that were part of before the passage of Settlement Act and have a National the Alaska since been selected and conveyed to a Native corporation will remain under the rules and regulations of the refuge. C. PROJECT DEVELOPMENT SCHEDULE A proposed project development schedule starting at the ':ime the initial draft is submitted is presented in Figure XI-1. The schedule is based on the assumption that two separate eontracts would be awarded for the project construction. The first would be for fabrication and delivery of the turbine- generator equipment to the Port of Seattle and later installation and the second would be for civil work construction and installation in cooperation manufacturer of the turbine-generator equipment. with the The controlling activities on the proposed schedule are the turbine-generator procurement and the construction period. 1. Turbine-Generator Procurement According to manufacturers' estimates, approximate! y one year fabrication NBI-419-9524-XI is (and necessary for turbine-generator delivery to the Port of Seattle) XI-3 starting from the time of contract award. In addi- t ion, prior to the award a two-month period must be allowed for aovertising, bid preparation, and bid evaluation. This in turn would be preceded by a three-month period to prepare specifications. 2. Construction Period The field construction period woula require two to three summer months of on-site activities, preceded by one to two months of shipping and mobilization time. Other critical tasks such as preparation of the civil plans and specifications, award of the civil contract, procurement of the necessary permits and license, and coordination of project- related activities with other affected agencies would be accomplished during the turbine-generator procurement phase; thus they are not directly controlling activities. As shown, the project construction would be completed about October 1, 1984. Following three months of commissioning and debugging time, the project would come on-line about January 1, 1985. NBI-419-9524-XI Xl-4 Activity 1. State of Alaska Decision 2. Secure Necessary Permits, Licenses 3. Turbine/Generator Contract a. Prepare Turbine/Generator Spec. b. Advertise & ~valuate Bids c. Fabricate Turbine/Generator d. Deliver Turbine/Generator to Seattle 4. Civil Contract a. Prepare Civil Plans & Specs. b. Advertise & Evaluate Bids 5. Construction Activities a. Mobilization Period b. Barge Shipment c. Site Mobilization d. Slte Construction 6. Power Plant Commissioning, Debugging Period 7, Plant On-Line NBI-410-9521-PDS FIGURE Xl-1 PROJECT DEVELOPMENT SCIIEDULE -~--~------··~---··--·-· 1982 1983 ------"-----,-- J F N A M J J A s 0 N D J F M A M J J A -- ----~-----------------, __ - ~-·--·~ 1984 ---... ----· s 0 N D J F M A M J J A s 0 N D • -..._ -- --, ____ -------~----' SECTION XII CONCLUSIONS AND RECOMMENDATIONS A. CONCLUSIONS On the basis of the studies completed for this report, the following conclusions can be drawn: 1. The energy demands of Old Harbor are sufficient to utilize the energy hydroelectric project. produced by the proposed 2. The Old Harbor Hydroelectric Project at the recommended capacity of 340 kW is a feasible project. 3. The proposed project is a more economic means of meeting the future electric needs of Old Harbor than the base case, or diesel, alternative. 4. The environmental effects of the proposed project are minor and will have no major temporary or long-term impacts. B. RECOMMENDATION In view of the conclusions enumerated above, it is recommended that actions be initiated to implement the project. Implementation can be accomplished along the general lines indicated in Section XI, Project Implementation. NBI-427-9524-XII XII-1 BIBLIOGRAPflY OLD HAH.BOR Alaska Department ot Fish & Game. Alaska's Fisheries Atlas, Volumes I and II, 1978. Alaska Department of Fish & Game. Alaska's Wildlife and ~abitat, Volumes I and II, 1973. Burk, C.A. Geology of the Alaska Peninsula -Island Arc and Continental Margin: Geological Society of America Memoir 99, 1965. CH2M HILL. Reconnaissance Study of Energy kequirements & Alternatives for Akhiok•King Cove•Larsen Bay•Old Harbor•Ouzinkie•Sand Point. For Alaska Power Authority, June 1981. Department of Commerce. ESSA -Environmental Data Service, Climatological Data Summary, Alaska. Ebasco Services, Inc., Regional Inventory and Reconnaissance Study for Small Hydropower Projects: Aleutian Islands, Alaska Peninsula, Kodiak Island, Alaska. Vols. 1 and 2, October 1~80. Ott Water Engineers. Water Resources Atlas for USDA Forest Service Region X, Juneau, Alaska. April 1979. Pewe, T.L. Quaternary Geology of Alaska: U.S. Geological Survey Professional Paper 835, 1975. U.S. Department of Energy, Alaska Power Administration. "Hydroelectric Power Potential for Larsen Bay and Old Harbor, Kodiak Island, Alaska." May 1978. NBI-419-9524-B U.S. Department of Energy, Alaska Power Administration. "::>mall Hydroelectric Inventory of Villages Served by Alaska Village Electric Cooperative," December 1979. U.S. Geological Survey. 11 Flood Characteristics of Alaskan Streams," Water Resources Investigation 78-129, R. D. Lamke. 1979. U.S. Geological Survey. "The Hydraulic Geometry of Some Alaskan Streams South of the Yukon River (Open File Report)," William E. Emmett, July 1972. U.S. Geological Survey. "Water-Resources Data for Alaska Water Year 1963 through Water Year 1980-1981." U.S. Geological Survey. "Water Resources of Alaska (Open File Report)"; A. J. Feulner, J. M. Childers, V. W. Norman; 1971. U.S. Geological Survey. 11 Water Resources of the Kodiak- Shilikof Subregion, South-Central Alaska," Atlas HA-612, S. H. Jones, et al., 1978. Woodward-Clyde Consultants. Valdez Flood Investigation Technical Report. February 1981. NBI-419-9524-B OLD HARBOR HYDROELECTRIC PROJECT FEASIBILITY STUDY APPENDIX A PROJECT DRAWINGS PLATE I PLATE II PLATE III PLATE IV PLATE V PLATE VI TABLE OF CONTENTS GENERAL PLAN INLET STRUCTURE AND ONE-LINE DIAGRAM PENSTOCK --PLAN, PROFILE, AND DETAILS DIVERSION FACILITIES --PLAN, ELEVATION, AND SECTIONS POWERHOUSE --PLANS AND SECTIONS TYPICAL CROSSARM CONSTRUCTION ASSEMBLY NBI-427-9524-TC ./ I ;F-' 1. ~- o_u) \ .. OLD EXISTING RCA8 A\JL T RAi\SMISSION 'LINE ) -----~ ~ ~-~ SHEEP ISLAND --~ \ 0> \ \ \ \ \._ ·DOCK / / ./ / / / \ \ / / / I i ]_ I I j__ 1l.. MILES 0 4 2 4 4 2 ~--~ LOCATION MAP NOT TO SCALE VICINITY MAP NOT TO SCALE / STATE OF ALASKA # ALASKA POWER AUTHORITY ANCHORAGE, ALASKA OLD HARBOR HYDROELECTRIC PROJECT GENERAL PLAN DOWL ENGINEERS ANCHORAGE, ALASKA TUDOR ENGINEERING COMPANY SAN FRANCISCO, CALIFORNIA PLATE I 1- UJ UJ "-z 362 350 ~~ ~ UJ ul 342 ···----... ···-----··· PLAN SCALE I" • 4' INLET STRUCTURE (GATES NOT SHOWN) ELEVATION SCALE o I" • 4' PENSTOCK MIDWAY CREEK 0 0 +I <D -.. LEL 356 0 PREFABRICATED STEEL WEIR SECTION A SCALE 1" • 2'-0 SYMM ABOUT i--.J GATE MODULE ~GATE NEOPRENE SEAL~ r STEEL FACE PLATE \ CROSS BRACE--------- SECTION 8 SCALE' 1" • 1'-0 SYMM ABOUT i GATE L 2 5 < 2 CONNECTION SUPPORT ' MAIN BRACE W 6 x g-------. ~ +' 1- t-l CROSS BRACE ST 2.5xJ ++ 1- ~ i :n: PIN SUPPORT lull I 3'-0 I I I 2'-o SECTION C SCALE' 1" • 1'-0 INLET STRUCTURE WALL 6" • ' ' + + + 16 ~ .. ~ INLET STRUCTURE WALL . ' .. Y STATE OF ALASKA ALASKA POWER AUTHORITY ANCHORAGE, ALASKA SCALE: I" • 1'-0 OLD HARBOR HYDROELECTRIC PROJECT 10 SCALE: I" 2'-o 20 SCALE: I" ; 4' 12 - 24 DIVERSION FACILITIES PLAN, ELEVATION AND SECTIONS OOWL ENGINEERS ANCHORAGE, ALASKA TUDOR ENGINEERING COMPANY SAN FRANCISCO, CAL I FORMA PLATE ll "' ::J f- <( 0 w f- "' f- w w "- z 0 >= <( > w --' w /DIVERSION FACILITIES 380 360 340 320 300 280 260 240 220 200 180 100..., 80 i 60 40j 20 EL 352 y u Lt z 0 0 0 '" + oc 0 w > <( _,f- OIUl TYPE I (ON TALUS) -DIVERSION FACILITIES I STATIO~ 'FEET NOTE ACTUAL ROADW MAINTAIN A GRAA; ALIGNMENT WILL E LESS THAN 10% PENSTOCK /ACCESS ROAD PLAN SCALE I"~ 100' PENSTOCK/ACCES< " ROAD TYPES ! ---1--TY p E li -1--- T 10 PENSTOCK I ACCESS 12 ROAD POWERHOUSE 21+80 -- 20 ~ 13 ~ 14 15 PROFILE OF SCALE "-, PENSTOCK /ACCESS ,-100 HORIZ __ R.=Oc::A..,D, -40' VERT TYPE Ill 16 0 L. ACCESS MIDWAY :~AD TO y DOCK I~ MILE I ~TRANSM TO OLD ~SSION LINE _ ARBOR ---1 ::: 340 320 300 280 120 (RING GIRDER \ g~5~E~ER . 12 __ _r--~~ 20 24 SCALE 1"~4 , -__r--, _ ____r----c_ 3-~0 ~ 120 160 SCALE 1"~40' _______r----,__ 500 600 ~~ 300 400 SCALE I"~ 100' _ ____r-----, - --24'~ STEEL PIPE --((RING GIRDER ~,,,~NATURAL GROUND ITAL .., ', SELECT ROADBED FILL US) BACKFILLED TRENCH A -12'- (TALUS) FIBERGLASS PIPE --3" SAND BEDDING 1'-o" EACH SIDE (TYP) TYPE II -LEVEL GROUND 12' SELECT ROADBEr .-ILL ' ~ BACKFILLED TRENCH 24" ~+=='--3" -FIBERGLASS PIPE ~-_j SAND BEDDING I O.D + 2'-o" ITYP) TYPE ill-SIDEHILL (SOIL) I ACCESS ROAD SCALE: 1"•4' STATE OF ALASKA ALASKA POWER ANCHORAGE AAUTHORITY • LASKA OLD HARBOR HYDROELECTRIC PROJECT PENSTOCK-P LAN , PROFILE, AND DETAILS TUDOR E SAN FR:~~~~i;lNG COMPANY 'CALIFORNIA ~~~~ ENGINEERS ORAGE' ALASKA PLATE GENERAL PLAN SCALE, 1", 20' TURBINE SPEED INCREASER . .-FLYWHEEL ,_ _j.lo PROFILE-SECTION A SCALE .1.", 1'-0 16 ./-GENERATOR EQUIPMENT MOUNTING SKID FENCE / FENCE ELECTRICAL SWITCHGEAR 24" ¢ PENSTOCK BEARING LUBRICATION SET TURBINE SHUTOFF VALVE PENSTOCK DRAIN PRESSURE ·TURBINE PROFILE SECTION B SCALE 1."~1'-0 16 0 0 4 20 SCALE 8 ·l ___ POWERHOUSE PLAN SCALE .!' ~ 1'-0 · .!', 1'-o 16 60 ~-L 16 24 ---, SCALE• 1", 20' PERSONNEL DOOR -EQUIPMENT MOUNTING SKID -GENERATOR ENTRANCE DOOR FLYWHEEL . --SPEED INCREASER GOVERNOR TURBINE ORIGINAL GROUND _,_- TAILRACE SECTION C SCALE ·I"~ 4' 8 _j STATE OF ALASKA ALASKA POWER AUTHORITY ANCHORAGE, ALASKA OLD HARBOR HYDROELECTRIC PROJECT POWERHOUSE-PLANS AND SECTIONS TUDOR ENGINEERING CQMR\NY SAN FRANCISCO, CAUFORN!A PLATE I[ : 0 -"' U) I 0 f'() ITEM NO. 0 3 b I c: 3 d 5 f 2 9 I ek 3' .. a" ___ a b Position of Guy when req1 d 1 d:7tt~, I 1 I ""'-bs I II f I ' • I r"~ • J Neutrol -~-~~~, -~---~- 1 I l I I I I ' I I lf;l ~-~ ek-d/1 ~~ ""-•• t~J lt.J Specify CIA for offset neutral assembly MATERIAL ITEM NQ Insulator, pin type eu 2 Pin, pole top, 20" i 2 Bolt, machine, ~a" a req d length j J Washer, 2 ~4" r2Y4" • ~.6. 1 ~tS hole bs I Pin,crossorm,stetl,5t8" x I03t4 • ee I Crossarm, 3''2" x 4 '12" a 8'-0" i 3 Locknuts MATERIAL Broce, wood, 28" Bolt, carriage, 3,8" a 4 }2' Screw, log, '12" x 4" ( Cl on!t_) Bolt single upset insuloted(CI only} Brocket_._offset...t.insuloted (CIA only) Screw, 109. 1/2"• 4" ( C lA only) 7.2112.5 KV., 3-PHASE CROSSARM CONSTRUCTION SINGLE PRIMARY SUPPORT AT o• )"0__5• ANGiE Jon I, 1962 Ct,CIA PLATE '2I OLD HARBOR HYDROELECTRIC PROJECT FEASIBILITY STUDY APPENDIX B HYDROLOGY TABLE OF CONTENTS A. GENERAL B. AREA DESCRIPTION c. DATA UTILIZED D. PROJECT STREAMFLOWS E. DIVERSION WEIR FLOOD FREQUENCY F. CONSIDERATION OF POTENTIAL RIVER ICE PROBLEMS NBI-427-9524-TC PAGE 1 1 4 5 11 14 A. GENERAL The following report provides the estimates, the method- ology, and the background data on stream flows near the village of Old Harbor, located on the Kodiak Island in soutn-central Alaska. Also included is a generalized write-up of potential ice problems in the vicinity of Old Harbor and elsewhere. Since the streamflows dictate the amount of energy that can be produced by a particular dam and power plant configuration, their accuracy critically affects the feasibility of the proj- ect. Although hydrologic information from the immediate vicinity of the project is very limited, information from other areas of Kodiak Island permit acceptable estimates to be made for the proposed Midway Creek power site. However, these estimates should be compared with the actual streamflows now being recorded at the site. This report describes the general characteristics of the Old Harbor region and the basin that feeds Midway Creek. The data used in the hydrologic analysis and streamflow and flood frequency data from Midway Creek are also presented. A list of references that are cited in the text is presented at the end of this appendix. B. AREA DESCRIPTION 1. Regional Setting Old Harbor is located on the southeast coast of Kodiak Island, 50 miles southwest of the City of Kodiak and 35 miles southeast of Larsen Bay, the site of another hydro feasibility study that was conducted at the same time as the Old Harbor study. Old Harbor shares with other regions of south Alaska the comparatively mild maritime climate controlled by the Japan Current that sweeps through the Gulf of Alaska. This current produces cool summers, mild winters, and moderate to heavy NBI-389-9524-B* 1 precipitation well distributed throughout the year. Most of the precipitation occurs when moist air from the ocean precipitates as rain or snow as it is uplifted along the 2000- to 4000-foot-high mountain range that extends southwest through the length of the island. The primary crest of the mount a in range is only eight miles inland from Old Harbor. Strong, continuous winds blow from the south as eastward-moving Aleutian lows pass through this region from December through March. Mean annual precipitation ranges from 40 inches in sheltered coastal locations to an estimated 1~0 inches on some mountain crests (Ott Water Engineers, 1979). The mean annual temperature of 410F at Kodiak ranges from a normal aaily mini- mum of 25oF in December and January to a normal daily maximum of 6ooF in August according to data from the Department of Commerce's Environmental Data Service. Mean annual runoff is typically eight cfs per square mile ( 109 inches) along the windward portion of the island. The mean annual low month produces only about one cfs per square mile of runoff (USGS, 1971). 2. Basin Description The preferred hydropower development site for Old Harbor is located on a creek that enters Midway Bay four miles northeast of the airstrip and two miles from the newer North Village development of Old Harbor. This previously unnamed creek enters Midway Bay near the mouth of Big Creek; thus the name "Midway Creek" was adopted for use in this stuay. At the site o! the proposed diversion dam, Midway Creek emerges from a hanging valley at 400 feet MSL and descends the glacial scarp of the wide Big Creek Valley steeply to a large, flat alluvial fan that the creek has built into Midway Bay. The 2.2-square- mile drainage basin above the diversion weir extends two miles NBI-389-9524-B* 2 to the northeast in a narrow valley flanked by 1200-to 2200- foot-high ridges. Vegetation is primarily grasses and alders. The stream gradient immediately upstream of the dam site is comparatively flat and it provides little potential for additional head gain by extending the penstock. This flatland could possibly be aaapted as an efficient storage site should a moderate-sized dam replace the proposed diversion weir. There are no lakes or glaciers in the basin. For 2200 feet below the weir, the stream descends steeply in an open valley through rapids and low falls constructed of large cobbles and boulders. At the 50-foot level adjacent to the proposed powerhouse, the stream enters a broad, flat alluvial fan and travels about one-half mile to its mouth. The fan is well forested and constructed of highly permeable silts, sands, and gravel. Surface flows infiltrate the fan alluviums and they have been observed to disappear completely for short reaches during periods of low flow. A limited amount of weather information for Old Harbor has been collected by the U.S. Department of Commerce 1 s Weather Service from 1968 to 1971. The precipitation records are complete only for the years 1969 and 1970; partial precipita- tion records exist for 1968 and 1971. The reported precipita- tion total of 26.60 inches for the year 1969 is only about half of the total prec ipi ta tion that fell in 1970 (58. 01 inches). The 1970 total is close to the long-term average precipitation of 56.71 inches for the city of Kodiak. A comparison of concurrent monthly precipitation at Old Harbor and Kodiak provides no direct correlation between the two areas of the island. The Kodiak precipitation totals for 1969 and 1970 are 69.71 and 55.06 inches respectively. Table B-1 lists monthly precipitation values at Kodiak and Old Harbor. The windward side of the orographic barriers with eleva- tions exceeding 2000 feet should receive more precipitation NBI-389-9524-B* 3 than the coastal areas. The relationship between mean annual precipitation and orographic barrier elevation was analyzed to improve the precipitation estimate for Midway creek. This analysis utilized sea-level precipitation records from exposed sites at the city of Kodiak and measured runoff from five nearby mountain basins subject to orographic precipitation. This analysis provided a value of 90 inches for the Midway Creek basin. This value was further reduced by 10 inches to compensate for the partial sheltering effect of Sitkalidak Island. Hence, the selected mean annual precipitation for Midway Creek was 80 inches. C. DATA UTILIZED Limited hydrology data exist in the Old Harbor area. A total of ten miscellaneous streamflow measurements were made by the USGS on four streams located north and west of Old Harbor during 1970, 1978, and 1979 (USGS, 1970, and USGS, 1981). Flow measurements were maoe for this study on Midway Creek at the powerhouse site on October 21, November 2, and December 28, 1981, and a stream stage recorder was installed on December 28. Measurements and stage records were also made on Ohiouzuk Creek in October before that power site was abandoned in favor of Midway Creek. USGS streamflow records from numerous gages on Kodiak Island were used to establish flow and orographic precipitation characteristics similar to those of Midway creek. Much of the data is summarized in the USGS Hydrologic Atlas for the Kodiak- Shilikof subregion (USGS, 1978). The 1963 to 1980 daily flow records of the Myrtle Creek gage (No. 15297200), located nine miles south of Kodiak, were also used extensively (U~li~, 1981). The short-term precipitation record from Old Harbor and long-term record from Kodiak were used indirectly. NBI-389-9524-B* 4 A report by Ebasco (1980) presented flow duration curves, regional estimating methods, and initial estimates of basin yield. The CH2M HILL report (1981) depended principally on the previously mentioned USGS statewide report (1971). D. PROJECT STREAMFLOWS Midway Creek at the site of the proposed diversion should be a perennial stream. The flow regime is seasonal, with higher flows occurring in May and June from spring snowmelt and in September and October from rainfall. A comparison of precipitation records from Old Harbor and Kodiak (Table B-1) indicates that the relative time distribu- tion of precipitation is similar at both stations. Old Harbor has a somewhat lower proportion of its annual precipitation during the summer. 1. Mean Annual Flow No streamflow data on Midway Creek exist except for a few sporadic point discharge measurements made during this stuay. As part of this study, a stream gaging station has been installed at the proposed powerhouse site. The paucity of data presently available dictated that the following estimating techniques be used to determine stream- flows within the region of interest: • modified rational formula • regional analysis • channel geomorphology Each one of these methods will be applied to the study area to determine values for mean annual flow. NBI-389-9524-B* 5 a. Modified Rational Formula Application of the modified rational formula is explained in detail in the Ebasco report (1980). Only the salient features of the method are provided below. The method requires that a gaged stream within the study area having similar weather patterns and groundcover to the ungaged stream be selected. A proportion is then set up, so that = Ag Aug where Qg and Qug refer respectively to gaged and ungaged streamflow in cubic feet per second and A is the drainage area. Factors to adjust precipitation and elevation data are incor- porated into this equation as follows: = (P) + (D.H)E Aug Ag P is the precipitation adjustment factor between the two water- sheds, t.H refers to elevation differential, and E is the elevation adjustment factor. In applying this procedure, Ebasco previously had paired the gaged stream Myrtle Creek near Kodiak with Midway Creek on the basis of the period of record and of basin and climatological simi 1 ari ty. Mean discharge records of Myrtle Creek area were analyzed in conjunction with long-term weather records at Kodiak to determine whether the observed values are "normal" or due to runoff from wet or dry series of years. A flow adjustment factor was derived by taking the ratio of the average annual rainfalls during the 16-year gaging record to that of long-term average rainfall during the period of weather records. The resulting factor of 0.86 was applied to the NBI-389-9524-B* 6 shorter term measured flow of 46 cfs. This analysis yields an adjusted mean annual runoff of 39.4 cfs or a unit runoff of 8.3 cfs per square mile (Qg/Ag in above equation) for Myrtle Creek. These values are lower than reported by Ebasco. They used a flow adjustment factor of 0.95. The precipitation adjustment factor (P) accounts for the precipitation difference between the area of gaged and ungaged stream. It is a ratio of long-term average precipita- tion between tne two basins. The precipitation adjustment factor between Midway and Myrtle Creek basins is similarly based on estimates of mean annual basin precipitations. The values used are 80 inches of precipitation for Midway Creek and 140 inches of precipitation for Myrtle Creek. This results in a precipitation adjustment factor of 0.57 between the two basins. The elevation adjustment factor is omitted. Standard planimeter procedures were used to calculate the drainage of 2.20 square miles that contributes runoff to the damsi te. Using the modified rational formula, the mean annual flow for Midway Creek is estimated to be 10.5 cfs. b. Regional Analysis The regional method described by Ott Engineers (1979) was first applied to the gaged stream Myrtle Creek to test its applicability. The maritime climate in the Old Harbor area is similar to that of the Chugach National Forest for which the method was developed; therefore, the regional method should provide reasonable estimates. This method yielded a mean annual flow of 43 cfs with 90 percent confidence limits of 35 and 52 cfs. This predicted value is within seven percent of tne measured flow of 46 cfs. The same method applied to the Midway Creek site with a mean NBI-389-9524-B* 7 annual precipitation of 80 inches gives a flow of 10.2 cfs. The 90 percent confidence limits are 9 and 12 cfs. c. Channel Morphology Channel geomorphology can be used to estimate both the mean annual flow and the mean annual flood by measuring channel dimensions that have been shaped by these streamf lows. The method is considered to give reliable estimates for some parts of the Oni ted States where estimating relations have already been defined. William Emmett (USGS, 1972) applied this method to bankfull stream geometry along the Trans-Alaska pipeline corridor with reasonable success. His data included four large streams in the Copper River basin that were potentially applicable to Kodiak Island. As part of the consultant's field work for the concur- reo t feasibility studies, four small streams on liod iak Is land were measured near stream gages. The combined data covered a range of 19 to 37,000 cfs mean annual flow and banKfull widths of 27 to 750 feet. Regression analysis of the data established a consistent relationship between gaged mean annual flows and the bankfull width of the channels within their vegetated floodplains. The resulting equation was Qma = .0083 w2.253 where coefficient of correlation = .995, and standard error of estimate= .12 log units (+32%, -24%). The average width of Midway Creek as measured in the field was 24 feet, which correlates with a mean annual flow of approximately 10.7 cfs with a standard error range of ~ to 14 cfs. NBI-389-9524-B* 8 d. Estimated Flow A mean annual flow of 10.5 cfs for the Midway Creek site is considered to be the best estimate based on available information and the confidence interval of the various esti- mates. The very close agreement of the three estimating methods lends considerable confidence to the value. The flow of 10.5 cfs is equivalent to 4. ~ cfs per square mile. The 4.8 cfs may be compared with the (1980) Ebasco estimate of 9.6 cfs (131 inches) on Midway Creek and CH2M HILL estimate of 8. 0 cfs ( 109 inches) on Ohiouzuk Creek. These other estimates appear to overestimate the available precipitation in this somewhat sheltered location. The 10.5 cfs value is also consistent with three current meter discharge measurements made at the site. Date October 21, 1981 November 2, 1981 December 28, 1981 Flow 31.0 8.6 11.5 The October 21 measurement followed two days of heavy rain. B. Flow Duration The flow duration curve for a potential hydroelectric site is the initial tool in sizing the turbine and estimating annual energy production. Where no continuous record is available at the site, the information must be transferred from gaged sites on the basis of their hydrogeological characteristics. NBI-389-9524-B* 9 The flow duration curve can be viewed as the time dis- tribution of flows about the mean annual flow; thus a dimen- sionless flow duration curve (the ratio uf the flow to the mean annual flow versus the percentage of time the flow is exceeded) can be developed for any gaged basin and directly compared wittl any other dimensionless curve. Within certain hydrogeologic regions, these curves often have remarkable similarity, particularly within the 15 to 80 percent exceedance interval. Thus regional curves can be developed. Curves from small, steep basins with bedrock near the surface and little ground- water contribution are typically steeper than those from larger basins that include swamps or lakes and a good aquifer. The Midway Creek basin belongs to the former group. A comparison of dimensionless curves from three basins on Kodiak Island 25 to 40 miles distant and one from Amchika Island 1200 miles to the southwest showed considerable similarity. On this bas is the Myrtle Creek curve developed from 17 years of daily record was adopted as the type of curve to use for small, mountainous maritime basins in southwest and south-central Alaska. The Midway Creek flow duration curve presented in Figure B-1 is based on Myrtle Creek with the flows scaled to the ratio of their respective mean annual flows in c (10.5/46). 3. Annual Hydrograph Based on the same data and reasoning that went into determining the mean annual flow and the flow duration curve, an annual hydrograph was developed based on monthly flows at Myrtle Creek. The Midway Creek annual hydrograph presented in Figure B-2 and Table B-2 was based primarily on the mean and standard deviations of the logs of the mean monthly flows recorded at Myrtle Creek during the 17 years of record. The data were scaled to the Midway Creek site by the ratio of mean annual flows. The range of monthly means shown in grey corresponds to NBI-389-9524-B* 10 roughly seven out of ten years. Thus the average monthly flow should lie below the indicated range at least one year in ten and above the indicated flow range at least one year in ten. E. DIVERSION WEIR FLOOD FREQUENCY Estimates of the magnitude and frequency of floods at remote sites such as the Midway Creek site must depend primarily on regional studies. These studies relate the calculated flood frequency of measured peak flows at gaging stations to their drainage basin characteristics such as area and precipitation by means of multiple regression analysis. The reasonableness of these estimates can be checked at the remote site by utilizing bank full channel geometry and high- water debris marks in the floodplain. This type of site evi- dence is used to make rough estimates of the mean annual flood and the five-to ten-year flood. Flood discharge at the site was estimated on the basis of three previous regional hydrology reports: USGS ( 1979), Ott Engineers ~979), and Woodward-Clyde Consultants. The USGS report employs the log-Pearson Type I II distri- bution to determine flood magnitude and frequency relations on the basis of data collected at 260 stations throughout Alaska. The details of the analysis are provided in the report. The Ott Engineers report was developed for the Chugach and Tongass National Forests on the Gulf of Alaska. The Chugach National Forest includes the east end of Kodiak Island and the prediction equations developed are considered applicable to the Old Harbor area. The Woodward-Clyde Consultants report ( 1981) was written for the City of Valdez and covers much of the same area of NBI-389-9524-B* 11 south-central Alaska as the Chugach National Forest equations developed by Ott Engineers. The three sets of flood predict ion equations were applied to botn the Midway Creek site and Myrtle Creek, the latter providing an approximate test for this region. BASIN PARAMETERS Site Area Precip. Temperature Percent of Area (sq. mi.) (in.) (Jan. mean min.) lake store. -forest Midway Cr. 2.20 80 240F 0 0 Myrtle Cr. 4.74 140 24oF 0 0 PREDICTED FLOOD FREQUENCY AT MIDWAY CREEK Method Peak Discharge for Recurrence Interval (years) 2 10 25 50 100 USGS (cfs) 370 540 560 670 740 (Standard error, %) 50 45 48 42 Ott (cfs) 140 250 300 340 400 Woodward-Clyde (cfs) -250 330 380 PREDICTED FLOOD FREQUENCY AT MYRTLE CREEK Method Peak Discharge for Recurrence Interval (years) 2 10 25 50 100 USGS (cfs) 930 1400 1510 1810 2000 Ott (cfs) 665 1110 1300 1480 1670 Woodward-Clyde (cfs) 1130 1470 1620 Based on Lamke's analysis of 14 years of measured flood peaks on Myrtle Creek, the 2-year and 10-year floods are 765 and 1020 cfs respectively. The maximum flood in that period, NBI-389-9524-B* 12 1, 110 cfs on September 14, 1969, has approximately a 10-year average recurrence interval. The mean annual precipitation used at Myrtle Creek is derived from the isohyetal map produced by Ott Engineers. It accounts for significant elevation and it is similar for Midway Creek. The increases in precipitation with to the basin precipitation derived USGS method produces much higher estimates with this precipitation value. However, if the mean annual precipitation of 80 inches derived from the earlier isohyetal map actually used by Lamke is substituted, the estimated 10-year flood is 1040 cfs. This appears to be a case where each method must be confined to the data on which the original regression analyses were based. With this limitation on precipitation estimates, there is good agreement among the three methods. Estimates of the two-year flood were also made based on field measurement of the bank full channel area and the channel geometry work of Emmett (USGS, 1972). Channel areas of 49 and 118 square feet correlated with two-year floods of 180 and 530 cfs at Midway Creek and Myrtle Creek respectively. The adopted flood frequency curve at the Midway Creek site based on the Ott Engineers equations is presented in Figure B-3. The 90 percent confidence limits adapted from the Ott Engineers analysis are also shown. The lines indicate that the true flood frequency would lie within these limits with a 90 percent level of confidence. The channel geometry analysis further increases the confidence in the adapted flood frequency. NBI-389-9524-B* 13 It should be recognized that in this environment the greatest depth and extent of flooding may not be due to peak discharges. Ice sheet and ice jam flooding are common. Uuring the normal winter freeze-thaw cycles, many layers of ice may accumulate and create temporary ponds that may release suddenly to inundate and jam the diversion weir. F. CONSIDERATION OF POTENTIAL RIVER ICE PROBLEMS 1. Formations of River Ice The occurrence and condition of the ice on rivers and reservoirs may require protection of water intake points from blockage. Several types of ice can form in natural rivers. One is called "sheet ice" and it occurs mostly on stagnant bodies of water and slowly flowing streams. This ice usually originates with plate or border ice and gradually propagates across the water surface until a continuous sheet is produced. Another type of river ice is called "frazil ice." by nucleation of slightly supercooled turbulent forms of frazi 1 ice are distinguished: active It is formed water. Two and passive forms. Passive frazil ice is not considered as detrimental as active, which sticks to any solid object at or below freezing temperature in the river. If the active frazi 1 ice adheres to the river bottom, it may contribute to the formation of anchor ice. One other form of river icing refers to a mass of surface ice formed by successive freezing of sheets of water that seep from a river. A river icing (to which the term auf eis is commonly restricted) is more particularly the mass of ice superimposed on the existing river ice cover. 2. Estimates of Ice Thickness The thickness a natural ice sheet can attain depenas upon the cooling potential of the atmosphere. In winter this is often expressed in freezing degree days, and the thickness NBI-389-9524-B* 14 reached at any time is expressed in terms of the square root of the degree days. Although several relationships have been developed to estimate ice thickness as a function of the cooling potential of the atmosphere, Stefan's simple equation ( 1889) is presented here to provide rough estimates of ice thickness. The Stefan equation in its original idealized form does not include the effects snow cover, wind, surface roughness, and other physical parameters. expression of Stefan's formula The following incorporates a coefficient a that presumably accounts for local effects such as snow cover and snow conditions. Values of a. are given in the following tabulation. FI is the freezing index and refers to the number of degree days below freezing for one year. Freezing degree days or freezing index values are obtained from NOAA climatological records. For the four small hydropower locations studied for this contract of which the Old Harbor Hydroelectric Project is a part, the following values of a. and FI have been chosen and the resulting river ice thicknesses are indicated. Site a. FI (°F-day) H (inches) --- Togiak 0.65 2225 30 King Cove 0.40 1400 15 Old Harbor 0.40 1500 16 Larsen Bay 0.40 1400 15 Estimates of river ice thickness are provided to aid the design of proper hydraulic structures and protect them from ice problems such as ice jams, icing, and improper placement of the intake. Note that these ice thicknesses are theoretical values NBI-389-9524-B* 15 and do not include the effects of wind, flowing water, and currents and snow cover. 3. Frazi 1 Ice More severe problems could potentially be experienced from frazil ice formation at the water intake point. Since very little is known about frazil ice formation, evolution, and subsequent disposition, rational design methods to avoid frazil-ice problems are lacking. Frazil ice formation has been observed at Midway Creek, Old Harbor, and Humpy Creek dam site in Larsen Bay. Particularly, Humpy Creek dam site appears to produce considerable frazil ice under natural flow conditions. Delta Creek dam site at King Cove may also experience similar ice problems. The Togiak Quigmy River project site has been observed to have floating ice blocks and ice jams that develop at naturally constricted channel locations. During the installation of a stream gage in December 1981, release of water from an ice-jammed reservoir upstream caused the stage to rise approximately three feet. Considerable quantities of floating ice blocks have oeen observed following the rise in stage. While little data are presently available, it is clear that the potential ice problem cited above must be considered in depth during the design phase of project implementation. These in-depth considerations should include an evaluation of condi- tions that cause ice problems, the extent of the problems to be encountered, and potential measures to alleviate or mitigate the problems. NBI-389-9524-B* 16 TABLE B-1 AVERAGE MONTHLY PRECIPITATION (inches) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Old Harbor 1968 N.A. N.A. . 55 5. 1 f) N.A . N.A. N.A. N.A. N.A. N.A. 7.20 1. 64 1969 1.48 2.82 0.88 1. 11 0.93 1. 61 T T 1.67 6.87 0.86 8.37 26.60 1970 2.25 18.81 3.86 2.74 3. 15 4.23 3.09 2.35 10.37 1. 35 3.23 2.58 58.01 1971 1.48 5. 24 3.74 5.02 6.46 8.28 N.A N. A. N. A. N. A. N.A. N. A. Kodiak 1968 1. 97 9.61 3.32 4.42 1. 97 2.07 7.60 3.68 5. 85 4.04 7.34 2.99 54.86 1969 .24 4. 13 3. 89 5. 46 3.30 7. 56 2.00 3.25 9.35 12.36 5.96 12. 19 69.71 1970 3.26 8.39 5. 96 1. 43 3.10 2.94 4.04 7.44 6.39 4.48 2.25 4.75 55.06 1971 6.74 8.82 4.28 4.31 11.89 8.50 7.96 4.86 6.59 4.70 4.52 2.30 75.47 Long term 5.01 4.89 3.85 3.61 4.35 4. 12 3.54 4.30 6. 11 6.29 5. 41 5.03 56.71 TABLE B-2 E:ST IMATED AVERAGE MONTHLY FLOWS AND DEVIATIONS (c fs) MIDWAY CREEK Jan Feb Mar AJ2r Ma~ ,Jun Jul Aug Se12 Oct Nov Dec Annual Average 13.7 10.3 6. 1 6.4 5.5 3.9 8.0 22. 1 19.3 7.7 8.6 14.8 10.5 High 22.7 18.4 15.9 19.6 18.2 11.9 16.7 31.2 34. 1 16.5 19.6 25.0 Low 8.3 5.7 2.3 2.0 1.7 1.1 3.7 15.6 10.8 3.7 3.7 8.8 NBI-389-9524-B-1 56 48 40 32 24 \ ~ \ ~ 16 ~ MEAN ~~NNUAL FLOW 10.5 cfs - 8 • .... 0 -~ ' I' ' .............. 9 u.. 0 0 20 40 60 I PERCENT ( 0/o} OF TIME FLOW EXCEEDED MIDWAY CREEK FLOW DURATION CURVE ....... -~ 80 100 FIGURE B-1 -.. -u - ESTIMATED RANGE OF AVERAGE MONTHLY FLOWS 7 OUT OF 10 YEARS I t I I I O JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MONTH -----------------------------------------------------------------MIDWAY CREEK AVERAGE MONTHLY FLOWS FIGURE, 8-~ .. EXCEEDANCE PROBABILITY 90 80 70 60 50 40 30 20 -... , ~ __:_·; ·~~~ --f -:-:~:J::::r-~·--:-r,-. -.. +-+-'-t~ ......., " + J • t ' · • ~ · j · · I ~ , -- 10 5 2 I 0.5 0.1 UJ 200 L90~~,CONF)DgN.CJ;_lftT~~:::t::=t:~~-i-t~~~-~--L.l~-.:.~-L_:_.. __ . ~ [ ESt.i+Eo1 Flcl:nk~ · ~Y----~ I _ : . . · 1 : 1. l . · 1 : ~ ~:1:~ r l . Q 100 :__ __ __.:.~ 1 : -I 2 5 10 20 50 100 1000 AVERAGE RETURN PERIOD IN YEARS MIDWAY CREEK FIGURE PEAK FLOW FREQUENCY CURVE 8-3 OLD HARBOR APPENDIX B References CH2M HILL, Reconnaissance Study of Energy Requirements & Alternatives for Akhiok•King Cove•Larsen Bay•Old Harhor•Ouzinkie•Sand Point. For Alaska Power Authority, June, 1981. Department of Commerce. ESSA -Environmental Data Service, Climatological Data Summary, Alaska. Ebasco Services, Inc •. Regional Inventory and Reconnaissance Study for Small Hydropower Projects: Aleutian Islands, Alaska Peninsula, Kodiak Island, Alaska. Vols. 1 and 2, October 1980. Grey, B.J. and D.K. MacKay, "Aufeis (overflow ice) in Rivers", Canadian Hydrology Symposium Proceedings: 79, Glaciology Division, Water Resources Branch, Inland Waters Directorate, Environment Canada, 1979. Michel, B., "Winter Regime of Rivers and Lakes", CRREL Monograph III-BIA, CRREL, Hanover, New Hampshire, 1971. Osterkamp, T. and Gosink, J.P., 'Letter written to Dept. of Commerce and Economic Development', January, 1~82. Ott Water Engineers. Water Resources Atlas for USDA Forest Service Region X, Juneau, Alaska. April 1979. Rhoads, E.M., "Ice Crossings", The Northern Engineer, Vol. 5, No. 1, pp. 19-24, 1974. NBI-389-9524-BR Stefan, J. "Uber Die Theorien Des Eisbildung in Polarmere", Wien Sitzunsber, Adad. Wiss., Ser. A, Vol. 42, Pt. 2, pp. ~65- 983' 1889. U.S. Geological Survey. "The Hydraulic Geometry of Some Alaskan Streams South of the Yukon River (Open File Report)," William E. Emmett, July 1972. U.S. Geological Survey. "Flood Characteristics of Alaskan Streams,11 Water Resources Investigation 78-129, R. D. Lamke. 1979. U.S. Geological Survey, "Water-Resources Data for Alaska Water Year 1978 through Water Year 1980." 1981. U.S. Geological Survey. "Water Resources of Alaska (Open File Report);" A. J. Feulner, J. M. Childers, V. W. Norman; 1971. U.S. Geological Survey, "Water ftesources of the Kodiak-Shilikof Subregion, South-Central Alaska,11 Atlas HA-612, S. H. Jones, et al. , 1978. U.S. Geological Survey. "Water-Resources Reconnaissance of tt1e Old Harbor Area, Kodiak Island, Alaska," John B. Weeks, 1970. Wahanik, R.J., "Influence of Ice Formations in the Design of Intakes", Applied Techniques in Cold Environments, Vol. 1, pp. 582-597. 1978. Woodward-Clyde Consultants. Valdez Flood Investigation Technical Report. February 1981. Yould, P.E., and T. Osterkamp, "Cold Region Considerations Relative to Development of the Susitna Hydroelectric Project", Applied Techniques in Cold Environments, Vol. 2, pp. d87-895, 1978. NBI-389-9524-BR OLD HARBOR HYDROELECTRIC PROJECT FEASIBILITY STUDY APPENDIX C GEOLOGY AND GEOTECHNICS A. B. c. D. E. F. G. TABLE OF CONTENTS INTRODUCTION. TOPOGRAPHY ••• REGIONAL GEOLOGY .•.. ENGINEERING GEOLOGY. 1. 2. 3 • 4. Diversion Site Geology. Construction Materials. Road/Penstock/Powerhouse Location. Ohiouzuk Creek •.•..•..••..••.••..••. SEISMIC HAZARDS ••••. . ............................. . l-1-ECHANICAL ANALYSIS. . ............................. . REFERENCES CITED .•••••..•••••.••.•••••.•••.•••.••.• i 1 2 3 6 6 7 7 9 10 13 15 Fi re 1 2 3 4 5 LIST OF FIGURES Geologic Time Scale •.........•.............•.. Reconnaissance Geologic Nap .................. . Road Location Map •......•............•........ S e ism i c Risk ~Ia p • • • • • • • • • • • • • • • • • • . • • • • • • • . • .• Gradation-Alluvial Fan ...................•.. ii 5 8 ll 14 APPENDIX C Geology and Geotechnics for the Proposed Old Harbor Hydropower Project A. INTRODUCTION In siting a hydropower development, it is important to understand the regional as well as the site-specific geology and geotechnics. Regional inforrnat ion is necessary to: ( 1) assess the geologic hazards, (2) assure that appropriate design criteria are utilized, ( 3) discover construction material borrow sites, (4) provide background information for environmental studies. This report discusses regional geology and seisrnici ty and the specific darn site, penstock/road routes, and the powerhouse loca- tion. Because of subtantial geologic hazards at the original site on Ohiouzuk Creek, the project site was moved to Midway Creek. An explanation of the geologic problems at Ohiouzuk Creek is included in this report. In accordance with the Scope of Work for this project, the information is intended for use at the de- tailed feasibility study stage. Geologic and geotechnical field studies were conducted September 18, October 19-22, and November 5, 1981, by Dr. R.L. Burk, Project Geologist and Team Coordinator, and J. Finley, Project Geotechnical Engineer. -1- B. TOPOGRAPHY Old Harbor is located in the south-central portion of Kodiak Island, Alaska, along the shores of Sitkalidak Strait. Sitkalidak Strait is a major feature which opens up to the Pacific Ocean at both ends. Old Harbor is situated near Sitkalidak Passage, a narrow arm of the Strait separating Kodiak Island from the smaller Sitkalidak Island. Sitkalidak Strait and many of its tributary bays were once filled with ice. As the glaciers retreated and the sea level rose, these former glacial valleys filled with water; they are now classified as fjords. Because multiple glacial advances have brought ice to this entire area, the hills are generally smooth and rounded, hanging valleys are common, and valleys tend to have a parabolic cross section. Elevations in the immediate project area range to approximately 2000 feet. The proposed stream diversion site is on a creek which is a tributary to Midway Bay and has been named Midway Creek for the purposes of this report. Midway Bay is a small bay which is part of Sitkalidak Strait near Old Harbor and Sitkalidak Passage. -2- C. REGIONAL GEOLOGY Plate-tectonic theory provides the basic ideas necessary to synthesize and understand the geology of continental margins and plate boundaries. Ocean trenches are viewed as sites of large- scale underthrusting of oceanic crustal materials. The sediments that fill these trenches are scraped from the downgoing plate and accreted to the overlying plate as this underthrusting con- tinues. Southwestern Alaska has a long history of being a zone of accretion for deep-sea deposits. The Kodiak Formation which constitutes the bedrock under- lying the Old Harbor site has been interpreted as a deep-sea trench deposit of Late Cretaceous age (see Figure 1) which has been accreted to the continent (Connelly, 1978). These rocks are for the most part marine turbidites and range from well-lithified siltstones to fine sandstones. Glaciation on Kodiak Island has probably extended from Miocene time (Pewe, 1974) to the present. The glacial deposits at Old Harbor date from Late Pleistocene time (Coulter, eta!., 1965). Both till and glacial outwash deposits are present (see Geologic Map, Figure 2). -3- GEOLOGIC TIME SCALE Subdivisions of Geologic Time Radiometric Ages (mil lions of years Eras Periods Epochs before the present) (Recent) Quaternary Pleistocene 1 • 8 (.) Pliocene -6 0 N Miocene 0 z 22 LLI (.) Tertiary 0 I I gocene 36 Eocene 58 Paleocene 63 (.) Cretaceous -0 14 5 ---- N Jurassic 0 V'J 210 LLI ::£ Triassic 2 55 Permian 28 0 Pennsylvanian 320 (.) Mississippian - 0 360 --- N Devonian 0 LLI ....J 41 5 < Si lurlan IL 465 Ordovician 52 0 Cambrian 58 0 PRECAMBRIAN (No worldwide subdivisions) Birth of Planet Earth 4,650 Figure 1. Geologic Time Scale -4- EXPLANATION I Ou Quaternary deposits, undivided glacial 'deposits, colluvium, stream deposits DOWL Alluvial fan deposits Kodiak Formation-turbidites, siltstones fine sandstones ENGINEERS Reconnaissance Geologic Map Midway Creek FIGURE 2 D. ENGINEERING GEOLOGY 1. Diversion Site Geology Midway Creek flows in a narrow gorge through rocks of the Kodiak Formation, glacial deposits, and colluvium onto an alluvial fan composed of sandy gravel (see Geologic Map, Figure 2). The bedrock in this area consists of very well lithi- fied, competent siltstones and very fine sandstones characteris- tic of Late Cretaceous turbidite deposits in this part of Alaska. The proposed east diversion weir abutment is situated in rocks of the Kodiak Formation. The rock is jointed but appears competent for the intended use. Minor amounts of loose rock will need to be removed however, no major blocks where sliding is imminent were observed. The proposed west abutment is rock which have been brought in by boulders in this area are large (up to in boulders of granitic glacial activity. The 10 feet) and will easily serve as darn abutment material. However, there may be a problem with water flowing around the boulders and decreasing slope stability. A silt or other impervious curtain is recommended along the west side of the "reservoir" area. Excavations at the proposed site may show that such a curtain is unnecessary; how- ever, it should be included in the initial cost estimates. Possibly some of the boulders may actually represent subcrop. The lack of contact zone alteration makes that seem less likely, although not impossible. Boulders of the same -6- composition occur as erractics higher up on the slopes above the creek, so at least some of these granitic boulders have undergone glacial transport. Permafrost is not present in this area. No springs or unusual groundwater conditions were observed during the field work. 2. Construction Materials Gravel is available from the alluvial fan (see Mechanical Analysis Section Figure 5). Less than six inches of overburden will need to be stripped off to reach usable gravel. Boulders of competent, relatively unweathered granitic rocks are available from the glacial deposits. These rocks are suitable for virtually all types of construction uses. 3. Road se Locations There is some possibility that the State Department Transportation and Public Facilities may build an airport on the alluvial fan below the diversion site. If so, this agency would provide access from Old Harbor to the airport. vlhile direct access to town would be advantageous, it is not considered necessary and it does not significantly affect the economics of road building for this project. Boats can easily be beached on the alluvial fan (see Road Location Map, Figure 3) and a road can be built up the fan. -7- DOWL ENGINEERS o' IIIII ROAD LOCATION MAP MIDWAY CREEK FIGURE 3 Due to the highly permeable nature of the gravel, only clearing of vegetation would be necessary for a truck trail on the fan. Above the fan the proposed road ~ould climb onto a bench in the topography and proceed to the dam site on this bench. To get up on this terrace, extensive cutting and filling would be necessary for approximately 75 yards. The terrace is composed of colluvium and boulder till. On top of the bench a preliminary cut would need to be made in the topography; then 18 inches of fill ma- terial would need to be brought in from the fan. Approximately 3,000 feet of road would be on the fan and approximately 1,500 feet of road would be on the terrace. The powerhouse would be built on the fan and the sand and gravel substrate has excellent bearing capacity for this use. No special geotechnical problems are anticipated at this site. 4. Ohiouzuk Creek The original site for the detailed feas ibi 1 i ty study was Ohiouzuk Creek. On the basis of a preliminary reconnaissance visit and more detailed work, this site was rejected because of geologic hazards. Numerous slide areas were present surrounding the proposed dam site, penstock alignment, and road. Incompetent rock, springs and the high rainfall levels in this area are con- tributing factors to hillslope failure. The slopes in most cases could not be cut back without bringing down large portions of the hillsides. The geologic conditions in this area are similar in a number of respects to the major slide area near the town of Kodiak. Bedrock outcrops are very sparse because of natural sliding in the Ohiouzuk Creek basin. Any construction activities would accelerate this slide activity. -9- E. SEISMIC HAZARDS Southwestern Alaska is part of an intense seismic zone which circumscribes the Pacific Ocean. l-1ost of the more than 150,000 earthquakes that occur worldwide each year occur in this Circum- Pacific belt and in a somewhat smaller belt which extends through southern Asia and the Mediterranean. Past earthquake damage in the study area has been princi- pally manifested in five separate forms which can act indepen- dently or in combination. 0 0 Surface faulting major and minor faults are present in the Old Harbor area; however, the rock at the proposed dam sites does appear to have been subject to fault slip. Strong ground motion over a 50-year design period, the maximum rock acceleration is expected (probability of exceedance = 10%} to be between 40 and 50%g (see Figure 4). This figure was prepared using actual earthquake epicenter and magnitude data for Alaska. o Ground failure -minor landslides have occurred in 0 this area in the past; that would affect the expected. however, no major slides integrity of a dam are Seiches these are long-period oscillations of enclosed water bodies. Because no reservoir is proposed, no destructive seiches are expected. -10- DOWL ENGINEERS SEISMIC RISK MAP -Peak Rack Acceleration FIGURE 4 o Tsunami -seismic sea waves could affect coastal areas, including the town of Old Harbor but not the dam site. -12- F. MECHANICAL ANALYSIS -13- @Alaska Testlab 4040 "8" Slreel Anchorage, Alaska 99501 Phone (9071 2711-1551 Sheet _ _!_ of 1 w. o. No._ DJ-34 io-· Date JL4lftZ _____ _ Technician !;i,_.N.._ ____ _ Textural Class __ Sandy Grav:.aL .... Client _ .Alaska_ .Powe.r Authority ... .. IC w z ... .... "' w u " "' .. Frost Class __ _ Plastic Propert.ies _____ _ Date Reeeived ___ .lj.4/82 _ Unified Class __ _GW___ ·-__ Project .A __ Haffir.o_ ____ .. Sample Number .. 4131 Location .... Midway .. creek. Sample Taken By .... ..clien.t. ____ _ ·~···~ ---· Figure 5 .. -- ··-Alluvial 10 ----gradation ------- fan G. REFERENCES CITED Connelly, W. 1978, Uyak Complex, Kodiak Islands, Alaska: A Cretaceous subduction complex: Geological Society of America Bulletin, v. 89, p. 755-769. Caul ter, H. W. and the Alaska Glacial Map committee, 1962, !iap showing the extent of glaciations in Alaska: u.s. Geologi- cal Survey Map I-415. Pewe, T.L., 1975, Quaternary Geology of Alaska: u.s. Geological Survey Professional Paper 835, 145 p. -15- OLD HARBOR HYDROELECTRIC PROJECT .FEASIBILITY STUDY APPENDIX D DETAILED COST ESTIMATE TABLE OF CONTENTS PAGE A. GENERAL 1 B. METHODOLOGY 2 c. MOBILIZATION AND SUPPORT COSTS 3 D. UNIT PRICES 4 NBI-427-9524-TC APPENDIX D DETAILED COST ESTIMATE A. GENERAL This appendix presents the method, backup data, and assump- tions used to estimate the cost of the recommended hydroelec- tric project. Following the presentation of the methodology are tables showing a breakdown of major cost i terns such as mobilization, labor and transportation. At the outset of the cost estimating procedure for the Old Harbor Power Project, it was determined that the unit-cost estimating method for material placement and other construction activities would not provide sufficient accuracy and confi- dence. Development of construction cost estimates with this method uses unit prices developed from estimates and bid tabulations on similar projects under similar conditions, in terms of geo- graphic location, weather, accessibility and other factors that may affect the cost. When available unit prices are not simi- lar in these respects, they must be adjusted to reflect the actual cost of the canst ruction i terns under the speci fie con- ditions. For this project, it was felt that the available data base of unit prices was not sui table. Typically, unit prices on remote Alaskan construction projects vary widely and seem to depend heavily on a contractor's approach in scheduling crews, transportation, shipping, and work schedules. NBI-427-9524-AD 1 The cost estimate herein was prepared by using the heavy- canst ruction estimating method and January 1982 costs. This method treats the project as a separate entity. The construc- tion cost computations are based on the use of construction equipment units, labor rates, labor productivity, working con- ditions, work schedule and sequence, subcontract prices, perma- nent material and equipment prices, and special constraints and requirements. B. METHODOLOGY The preliminary design and layout of facilities was used to establish estimated quantities of permanent and consumable materials and other measurable items of work such as excavation and embankment quanti ties. A construction schedule was pre- pared for each major item of work, based on assumed production rates normally attainable under similar conditions. Considera- tion was given to the remote location, 60-hour work week, and short construction season. Construction equipment of appropri- ate size and type for each operation was selected with a view toward minimizing the number of pieces of equipment and using each piece to its optimum capacity. The manpower from the standpoint of crafts and the numbers of persons; hours of equipment operation; quantities of consum- able supplies and spare parts; subcontracted work; and the required permanent materials and equipment were estimated for each work i tern. The applicable rates and prices were applied to produce direct costs of labor, equipment, and materials. It was assumed that all skilled construction personnel will be brought to the site by the contractors since it is not known whether local labor will be available. Table D-1 lists the skilled personnel that will work on the project, and tabulates the number of man-weeks required for each craft. Also indi- cated is the weekly wage for each craft. The wages are based NBI-427-9524-AD 2 on union scale, including benefits, current as of January 1982. A work week (man-week) consisting of six ten-hour days is assumed. If the contractor chooses to increase the number of working hours per man-week, the weekly wage will increase, but the overall labor cost will not, since the duration of the construction period will decrease accordingly. Also included in the work force are subcontracted person- nel. A heavy equipment moving crew will transport the turbine/generator assembly from the barge unloading site to the project site and install it in the final position. An erection crew will assemble and install the prefabricated metal power- house building on the concrete foundation. The transmission line subcontract labor force is not included in Table D-1 and is excluded from the labor cost; however, the required camp cost to support this crew of eight is shown. A detailed breakdown of the transmission line subcontract is presented in Table D-8. The subcontract amount is based on January 1982 costs for power lines connecting the potential hydroelectric site to existing village power plants. Loads and distances can easily be handled with distribution voltages ( 12.47 kV). Therefore, popular REA-type assemblies and con- ductors were assumed. A typical crossarm construction assembly is shown on Plate VI, Appendix A. Equipment costs presented in Table D-2 are based on an hourly ownership rental for 21 weeks plus an hourly use rate for the actual hours used. The rates used are from actual costs of operating, owning, and maintaining equipment. They include fuel costs at Alaskan rates. Material costs are current costs for the items delivered to Seattle, Washington, at a barge departure point. They are shown in Table D-3. NBI-427-9524-AD 3 C. MOBILIZATION AND SUPPORT COSTS Due to the remote location of the site, essentially all of the equipment, vehicles, and supplies required to construct the project will be transported to and from the site by barge. Barges can operate from several points, including Seattle and Anchorage. The actual departure point would depend on the contractor's particular situation. This cost estimate is based on a barge departing Seattle in late April or early May, using material prices FOB Seattle and barge rates from Seattle to Old Harbor (see Table D-4.) Barge time to the project site is approximately two weeks. Table D-4 summarizes barge shipping costs both to and from Old Harbor. The construction workers and supervisory personnel will be housed in a construction camp set up specifically for this project. Table D-5 shows the overall cost, based on a unit cost per person-day assuming that each person-week of labor will require support for one person for seven days. The cost includes mobilization and demobilization of the camp and all other supportive costs. Air transportation support costs are shown in Table D-5. These costs cover the trips that would be required for a pro- ject of this nature and an anticipated personnel turnover rate of about 20 percent. Table D-6 is a summary of all direct costs associated with the construction of the Old Harbor project. A contingency of 15 percent and a markup of 15 percent for contracor overhead and profit are included. The cost of the transmission line is based on a subcontract cost that includes a contingency. As indica ted, it is marked up by 10 percent to cover the prime contractor's indirect expenses associated with scheduling and responsible supervision. Engineering and owner's legal and NBI-427-9524-AD 4 administrative costs are added to produce a total project cost. D. UNIT PRICES Figure D-1 is a construction schedule for the Old Harbor Power Project. Based on a detailed analysis of the construc- tion activities and the information presented in Tables D-1 through D-5, all of the direct costs were assigned to an appro- priate category that represents a major i tern of work. Unit prices were calculated and these are presented in Table D-7. They take into account the assumptions previously used for production rates, support equipment, and supervisory effort. Page 2 of Table D-7 details the content of the various cost headings and item descriptions. Finally, a detailed breakdown of unit prices, quanti ties, and total cost is presented in Table VIII-1. These are based on the average unit costs for major categories presented in Table D-7 and modified to take into account the quanti ties, scheduling, and locations of the specific items of work within the project area. Therefore some unit prices may vary for the same item used on different phases of the work. Note that the cost estimate prepared for this project was not based on the unit-cost method. The unit prices presented in this report are intended for use in presenting the general relationship and magnitude of the major construction items for this particular project. They should not be used out of con- text because they may not accurately represent the cost of performing similar work at other sites or under different cir- cumstances. NBI-427-9524-AD 5 TABLE D-1 OLD HARBOR LABOR BASED ON 60 HR. WEEK Labor Cost/ (Man Weeks) Week Total Cost General Superintendent 17 $1,986 $33,762 Superintendent (Crew A) 6 1,758 10,548 Operators (Crew A) 18 1,730 31,140 Oilers 10 1,575 15,750 Mechanics 10 1,730 17' 300 Laborers (Crew A) 29 1,571 45,559 Driller/Powderman 2 1,730 3,460 Superintendent (Crew B) 10 1,986 19,860 Electrician 5 1,850 9,250 Ironworkers 4 1,840 7,360 Carpenters 8 1,637 13' 096. Apprentice Carpenter 8 1,571 12,568 Operators (Crew B) 13 1,730 22,490 Millwrights 3 1,800 5,400 Finishers 4 1,571 6,284 Welders, Fitters 2 1,897 3,794 Laborers (Crew B) 32 1,571 50,272 Manufacturer's Rep 3 10,000 Line Crew (8) 64 Subcontract K.D. Bldg. Crew (3) 3 Subcontract 10,000 Heavy Equipment Moving Crew 3 Subcontract 25,000 TOTALS 254 Man-Weeks $349,450 NBI-419-9524-D-1 TABLE D-2 OLD HARBOH. EQUIPMENT COST Ownership Total Hourly Total Expense Operating Operating Operating Cost This (23 wks) Hours Cost Cost Project CAT-D8K $67,600 310 $103.22 :l;32,000 $ 99,600 Front End Loader 966D 18,800 250 30.06 7,515 26,300 Flatbed Truck 4,100 250 14.57 3,640 7,700 Dump Truck (10 yd) 8,350 250 16.87 4,220 12,600 Service/Fuel Truck 10,850 310 17.20 5,330 16,200 Airtrack/Compressor 25,350 100 27.00 2,700 28,050 Pickup Truck (2 ea) 3,250 ea 310 ea 12.69 ea 3,930 ea 14,400 Backhoe -CAT 225 24,900 310 20.37 6,320 31,200 Welder 1,100 70 5.51 390 1,500 Generator 510 620 .94 580 1,100 Generator Spare 510 80 .94 80 600 Hand Compactors (5 ea) 1,800 ea 180 ea 1.00 ea 180 ea 9,900 Cone. Mixer Trailer 2,000 70 2.50 180 2,200 Small Mixer (3 ea) 250 ea 30 ea 1.00 ea 30 ea 300 Screening Plant 9,300 220 23.75 5,230 14,500 3" \'Vater Pumps (3 ea) 500 ea 310 ea 1.00 ea 310 2,400 Fuel Tank, Bladder 5,000 5,000 Cutting Torch, Set 300 300 Misc. Equipment 2,000 2,000 Pole Setting Truck Costs contained in transmission subcontract Line Truck Office Trailer 3,000 620 1. 68 1,040 4,040 TOTAL :$279,900 NBI-419-9524-D-2 TABLE D-3 OLD HARBOR MATERIAL FOB SEATTLE Item Quantity Unit Unit Price Amount 1. 2. 3. 4. 5. 6. 7. Cement Type I Reinforcing Steel Fiberglass Pipe -24" Steel Pipe -24" 24" Dresser Couplings Welded Ring Girder Prefabricated Steel Units Steel Dam Modules Offtake Structure Sediment Basin 8. Turbine Generator Assy. Includes Switchgear 9. Electrical & Mechanical Accessory Equipment and Materials 10. Culvert Materials -100' 11. Blasting Powder 15. Steel Building Kit 16. Forming Materials 17. Misc. Structural Steel MATERIALS FOB SEATTLE DOCK NBI-419-9524-D-3 1,250 14,375 1,200 1,000 25 50 1,120 3,500 8,000 1 1 1,560 7,500 1 1 1,000 Bags Lbs Ft Ft Ea Ea Lbs Lbs Lbs $ 4.73 0.35 40 40 200 70 1.50 1. 50 1.50 $5,920 5,030 48,000 40,000 5,000 3,500 1,680 5,250 12,000 Ea 220,000 Lot 61,500 61,500 Lbs 1.00 1,560 Lbs 1.00 7,500 Ea 25,000 25,000 Lot 5,250 5,250 Lbs 0.30 300 $447,500 Haul Class A B c D E F G H I J I J TABLE D-4 OLD HARBOR BARGE SHIPPING COST Seattle To Old Harbor Weight Commodity (Typical) (lb) Structural Steel 31,741 Palletized Cement 117,500 Lumber 5,000 Poles 69' 300 KD Metal Bldg 15,000 Steel Pipe, Cuvert 61 '000 Misc. Wire, Hardware, etc. 50,780 Fiberglass Pipe 21' 120 Large Equipment, Machinery 390,500 Trailer 12,000 TOTAL ($/cwt) 8.24 6.93 8.00 8.00 12.50 8.24 24.32 16.48 12.00 25.00 Old Harbor to Seattle (Return) Large Equipment, Machinery Office Trailer TOTAL 333,000 12,000 12.00 25.00 NBI-419-9524-D-4 Cost (S) 2,620 8,150 400 5,550 1,880 5030 12,350 3,480 46,900 3,000 $133,400 40,000 3,000 $ 43,000 ESTIMATE OF CAMP COSTS 254 Man-Weeks TABLE D-5 OLD HARBOR Each week the men are supported for seven days 254 x 7 or 1778 days @ $135 per day CAMP COSTS TOTAL ESTIMATE OF AIR TRANSPORTATION COSTS Bring in crew and small tools -assume 6 men per flight and 24 men with a Beech King Air. 4 Trips Anchorage to Old Harbor and back @6 hrs/round trip 4 Trips @ $2500 Approximately 1500 lbs of freight via Reeve Aleutian and Air Taxi twice a week 3000 lbs @ $0.75/lb or $2250 per week 13 Weeks @ $2250 40 One Way Trips during construction for per- sonnel changes & supervisor visits 40 Trips @ $282 Misc. Supply Trips 4 Trips Queen Air Cargo Remove crews at job close AIR TRANSPORTATION TOTAL NBI-419-9524-D-5 $240,000 $10,000 29,250 11 '280 10,000 10,000 $71,000 Material FOB Seattle Labor TABLE D-6 OLD HARBOR SUMMARY SHEET Transportation -Barge to Site Transportation -Barge to Seattle Transportation -Air Camp Costs -Catered Equipment Cost Prime Contractor 15% Profit Contingency 15% Transmission Line -Electrical Labor & Materials Subcontract Prime Contractor 10% Markup Surveying, Right of Way & Geology Engineering Design Construction Management Owner's Legal & Admin. Costs 3% Subtotal Subtotal Subtotal Subtotal GRAND TOTAL NBI-419-9524-D-6 s 447,500 349,450 89,000 43,000 71' 000 240,000 279!900 1,519,850 228!000 1,747,850 262,180 575,000 57,500 2,642,500 50,000 175,000 125,000 350,000 89,800 $3,082,300 TABLE D-7 OLD HARBOO DEVELOPMENT OF AVERAGE UNIT PRICES FOO MAJOO ITEMS OF WORK 1/ Material Labor Equipment Contractor Total Unit Item-Cost Cost Cost Profit (15%) Amount Quantity Unit Price 2/ 1. Mobil/Demob. $166,710-$49,620 $23,000 35,900 $275,230 LS $ 2. Penstock -Steel 53,390 23,560 8,420 12,810 98,180 1,000 LF 98 3. Penstock -Fiberglass 49,740 27,210 43,050 18,000 138,000 1,200 LF 138 4. Rock Excavation 9,330 70,110 110,500 28,490 218,430 7,500 CY 29 5. Road Exc., Com. 0 46,700 80,650 19,100 146,450 8,400 CY 17 6. Culvert Pipe 1, 710 2,450 1,420 840 6,420 100 LF 64 7. Gravel Fill-Road 0 11,700 8,080 2,970 22,750 987 CY 23 8. Concrete 25,992 117,000 14,600 23,640 181,230 125 CY 1,450 9. Transmission Line 3/ 11 '250 60,480 0 10,760 82,490 LS 10. Prefab Steel Bldg 26,236 12,835 1,420 6,070 46,560 LS 11. Turbine & Generator 285,380 115,000 7,000 61 '110 468,490 LS 12. Prefab Steel Structures 19,980 14,500 4,800 5,890 45' 170 12,620 LB 3.58 13. Dock Constr. 1,000 5,040 9,990 2,410 18,430 lS TOTAL $228,000 $1,747,850 4/ 1/ These items are described on page 2 of this table. 7/ Includes Barge and Air Support Costs only. 3! Includes costs over and above subcontract amount only. 4/ Amount corresponds with second subtotal on Table D-6. NBI-419-9524-D-7 ITEM 1. Mobilization/Demob 2. Penstock, Steel 3. Penstock, Fiberglass 4. Rock Excavation 5. Road Exc., Common 6. Culverts 7. Gravel, Road 8. Concrete 9. Transmission Line 10. Prefab Steel Bldg. 11. Turbine & Generator 12. Prefab Steel Structures 13. Dock Construction COLUMNS Material Cost Labor Cost Equipment Cost NBI-419-9524-0-7 TABLE D-7 (Cont'd) Includes general superv1s1on, barge and air support costs, staging equipment, miscellaneous standby equipment, etc. Installed, including couplings, ring girders, excavation & backfill (unclassified). Installed, including bedding, excavation & backfill (unclassified). All, including road, penstock route and structural. Unclassified road excavation. Installed. Road fill, borrow, including haul. All, including equipment, material, cement, forming, miscellaneous structural excavation (unclassified) & reinforcing steel. Installed -Subcontract plus shipping and camp costs. Installed. Installed, including mechanical, electrical, and startup. Installed, including structural excavation for diversion dam. Installed. Material cost FOB Seattle plus shipping. Salary at 60 Hrs/week plus subsistence costs. Ownership rental plus use rental, based on six months. TABLE D-8 OLD HARBOR BREAKDOWN OF TRANSMISSION LINE SUBCONTRACT ITEM Poles Crossarms, insulators & guys Wire Subtotal, Overhead Transformers, Pads and Sectionalizing Equip. Subtotal Contingency: 25% Labor 10% Materials Subtotal Equipment Mobilization Misc. crew transportation and supervision Total SAY Material Cost $25,200 18,765 20,698 64,663 39,800 104,463 Labor1/ Cost- $107,100 64,549 110,880 282 '529 22,100 304,629 Total Cost .$132,300 83,314 131,578 347,192 61,900 409,092 76' 157 10,446 $495,695 50,000 28,800 $574,495 $575,000 Based on 75 $/man hour and 425 $/crew hour for a 5 man crew, including: 1 backhoe, 1 line truck with digger, 1 crew cab pickup, and wire stringing equipment. NBI-419-9524-D-8 FIGURE D-1 OLD HARBOR CONSTRUCTION SCHEDULE Activity Week 2 3 4 5 6 7 8 9 10 11 12 13 1. Barge Travel 2. Mobl llzatlon/Demobl llzatlon a. Set Up Camp/Demobilize b. Stage Material 3. Road Construction & Penstock Route 4. Penstock Construction a. Underground b. Steel c. Testing 5. Powerhouse a. Concrete Work b. Set Turbine-Generator c. Erect Building d. Mechanical & Electrical e. Startup 6. Diversion Site a. Concrete Work b. Set Prefab Steel 7. Cleanup 8. Transmission Line 9. Dock Construction OLD HARBOR HYDROELECTRIC PROJECT FEASIBILITY STUDY APPENDIX E ENVIRONMENTAL REPORT A. B. c. D. E. F. G. H. I. J. K. L. M. N. o. P. Q. R. s. T. u. v. w. x. TABLE OF CONTENTS PROJECT DESCRIPTIONS SCOPE OF WORK HYDROLOGY FISHERIES . . . . ..... . . .. . . CURRENT UTILIZATION OF FISHERY RESOURCES . .. PHYSICAL STREAM DESCRIPTION . . . . .. FISHERY IMPACTS FISHERY MITIGATION WILDLIFE . ... • ••• .... CURRENT UTILIZATION OF WILDLIFE RESOURCES ENDANGERED SPECIES WILDLIFE IMPACTS WILDLIFE MITIGATION VEGETATION . . . . . . . ARCHAEOLOGIC AND HISTORIC SITES POTENTIAL VISUAL IMPACTS IMPACT ON RECREATIONAL VALUES . ....... . AIR QUALITY SOCIOECONOMIC IMPACTS LAND STATUS PERMITTING REQUIREMENTS RECOMMENDATIONS REFERENCES CITED PERSONAL COMMUNICATIONS . . . . . . . . . .. i . .. . ...... . . .... . .... . ...... . . .... . ..... . .. . .... . ..... . .. Page 1 1 2 4 6 7 7 9 10 11 12 12 21 22 22 22 23 23 23 25 26 28 28 29 Figure 1 Tables 1 LIST OF FIGURES Project Location Map LIST OF TABLES Water Quality Data, 1981 2 Species and Number of Fish Caught 4 in Mid way Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Terrestrial Mammals of the Kodiak Island Archipelago •.••••...............•...... 13 4 Birds of the Kodiak Island Archipelago 14 LIST OF PHOTOGRAPHS Photographs 1 Proposed Dam Site, Downstream View .....••.•... 3 2 Proposed Dam Site, Upstream View ......•.•...•. 3 3 Upstream View of Midway Creek Alluvial Fan 8 4 Subst~ate on Midway Creek Alluvial Fan ........ 8 ii A. PROJECT DESCRIPTION A small diversion weir is proposed at an elevation of 400 feet (MSL) on an unnamed stream (hereafter referred to as Mid- way Creek) for a run-of-the-river hydroelectric project with a power output of 340 kilowatts. Water would be diverted into a penstock, leading to the powerhouse located on the alluvial fan. A transmission line would lead from the powerhouse across the Big Creek delta to Old Harbor. A barge landing would be built on the beach, and a road would be constructed on the alluvial fan to the powerhouse. B. SCOPE OF WORK As contracted with the Alaska Power Authority, environ- mental studies were to include an initial two-day reconnais- sance visit, followed by a three-to four-day trip for more detailed studies. Literature review and discussion with local residents and agency members were to be combined with field studies to obtain information on fish and wildlife resources in the area, and effects of the project on these resources. Hydrology, land status, archaeologic and/or historic sites, and permitting requirements were to be briefly dis- cussed, as well as impacts on recreational values, air quality, socioeconomics and scenic viewpoints. The reconnaissance visit occurred on September 19, 19 81, and a more detailed site investigation occurred November 5-6, 1981. Midway Creek was walked from the mouth to above the dam site and minnow traps were selectively placed throughout its length. Numbers and locations of wildlife and wildlife signs were noted. Local residents were contacted through a community meeting on September 19, 1981, and through discussions with -1- individuals during both visits. Downstream and upstream views of the proposed dam site are presented in Photos 1 and 2. The Alaska Power Authority held an informational meeting to discuss four potential hydropower sites, including Old Har- bor, with interested federal, state and local organizations in Anchorage on October 21, 1981. Additional contacts were made by DOWL with state and federal agencies on an individual basis during September, October and November. C. HYDROLOGY Midway Creek is three miles northeast of Old Harbor and it has a drainage area of 2.2 square miles at the dam site. It is a short creek (3.7 miles long} with a steep gradient ( 0.1 ft/ft). It has developed an alluvial flood plain near the mouth of Big Creek where it discharges into Midway Bay. The streambed material consists of silt, sand and gravel with- in the floodplain with large cobbles and boulders upstream in the steep portions of the creek. Mean annual flow is esti- mated at 10.5 cfs. The low flows are in the dry months (April, March, and July}. High flows occur in September and October and are caused by rainfall runoff. Additional information on hydrology is given in Appendix B. Water quality information for Midway Creek is given in Table 1, and locations are shown in Figure 1. -2- Proposed dam site, downstream view Proposed dam site, upstream view TABLE 1 WATER QUALITY DATA, 1981 Temp. D.O. Conductivity Date Location (OC) _@__ (mg/1) (Micromhos/cm) 11/5 Staff Gage 0.1 6.7 14.4 53 11/5 Dam Site 0.3 5.9 14.2 55 D. FISHERIES Alaska's Fisheries Atlas, Volumes I and II (ADF&G, 1978), shows Dolly Varden char as the only fish present in Midway Creek. Alaska Department of Fish and Game (ADF&G) aerial sur- veys have not shown any salmon in this stream (Manthey, 1981) and it is not classified as an anadromous stream (ADF&G, 1968). Local residents indicated that a few pink salmon usually ascend the stream a short distance. However, the lower portion of the stream is normally dry in the winter, so if spawning does occur, it is unlikely that many eggs survive the winter. Dolly Varden char and rainbow trout were caught in minnow traps in the lower portion of the stream (Table 2). Pink salmon generally spawn intertidally or in the lower reaches of short coastal streams. Medium sized gravel (0.6 to 0.3 inch) is preferred, with an optimum streamflow velocity of 0.1 feet per second or greater (ADF&G, 1978). No pink salmon were observed in Midway Creek, but they probably spawn intertidally and in the lower reaches of the river. Pink salmon migrate to saltwater immediately upon emergence. -4- EXPLANATION .,...Propoaed Dam Site -Stream Reach Dlvlalona $ Water Quality Sampling Site Sitkatidak Strait Sitk alidak Island SCALE I' 63 360 I I 2 0 I MILES ---- I~ PROJECT LOCATION MAP I FIGURE 1 I 200 100 3 10 TABLE 2 SPECIES AND NUMBER OF FISH CAUGHT IN ~UDWAY CREEK November 5-6, 1981 Trap Location Juveniles Causht yards below proposed powerhouse No Fish yards below proposed powerhouse 6 Dolly Varden 1 Rainbow yards above stream gauge 1 Dolly Varden yards above stream gauge No Fish Rainbow trout are reported to spawn in moderately swift, clear water, usually in fine gravel (0.3 to 0.16 inch) on a riffle above a pool. Juvenile rainbow trout are found along stream margins or protected lakeshores. Dolly Varden char spawn in medium to large gravel (1.3 to 0.3 inches) in a fairly strong current, usually near the center of the stream in at least a foot of water ( ADF&G, 1978). Juvenile Dolly Vardens remaining on the stream bottom and logs or undercut banks. are relatively inactive, often in pools or eddies under rocks Dolly Varden occur in both anadromous and nonanadromous populations. Anadromous juveniles spend three to four years in their natal stream before entering saltwater. E. CURRENT UTILIZATION OF FISHERY RESOURCES No sport fishing occurs in Midway Creek, but locals prob- ably do harvest salmon from Big Creek for subsistence use. -6- F. PHYSICAL STREAM DESCRIPTION Midway Creek is short (3.7 miles), it has a steep gradient (0.1 ft./ft.), and it enters saltwater to form an alluvial fan one-half mile in length. Near the dam site, the stream ap- peared to flow through a series of cascades with deep pools in between. Below the dam section, the gradient is steep and pools are absent until just above the alluvial fan. The substrate in this section was almost entirely large boulders, with some cob- ble and pebble gravel in the lower portion. Photos 3 and 4 show the Midway Creek Alluvial fan and substrate. The stream delta has a low gradient (two percent), with small cobble and pebble gravel substrate. Local residents stated that this section of the stream is normally dry during the winter. Midway Creek was dry for about three-quarters of the length of the alluvial fan at the time of the November visit. G. FISHERY IMPACTS Construction activity may temporarily increase erosion and sedimentation in Midway Creek. Major impacts from sedimenta- tion can include decreased vigor or death of incubating sal- monid eggs by interfering with or preventing respiration, loss of spawning gravel, and physical disturbance to both adult anadromous fish and resident species. Proper construction techniques and timing should minimize this impact. The portion of r1idway Creek between the diversion weir and the powerhouse may be dewa tered during low flows, and a major reduction in flow will occur during plant operations. This may seasonally restrict Dolly Varden from utilizing this stream -7- Upstream view of Midway Creek alluvial fan. Sub s tra te on Midway Cr ee k alluvial f a n. section. However, several small tributaries JO~n Midway Creek in this section, and may partially offset the effects of flow diversion at the dam site. Impacts to pink salmon are consid- ered negligible since this section does not appear to have suitable spawning habitat. H. FISHERY MITIGATION The following measures should be followed to reduce ero- sion and sedimentation of area streams: Construction should be done during a single sum- mer. This will reduce the opportunity for ero- sion of exposed soil. Instream work should be scheduled during low flow periods to reduce the amount of streambed disturbance. To avoid the introduction of suspended solids by road traffic, the access road should cross as few tributary streams as possible, and culverts should not discharge directly into streams. Streams should be crossed with small log bridges or culverts, whichever would provide the best protection to streamside vegetation. If the unimproved road can be designed with minimum use of gravel and not expose large areas of soil to erosion, impacts will be greatly minimized. A vegetated buffer zone should be left between all access roads and the streambank. -9- All areas disturbed during construction activ- ities should be stabilized to reduce erosion. Any organic soils excavated during construction should be stockpiled and spread over disturbed sites to encourage revegetation. Waste petroleum and wastewater should be dis- posed of in an environmentally sound manner and a plan for safe storage, use, and clean-up of oil and gas used in project construction and operation will be prepared following state and federal oil spill contingency plans (40 CFR 112.38, December 11, 1973). I. WILDLIFE Unless otherwise noted, all information specific to the Old Harbor area was obtained through correspondence and a meet- ing with Roger Smith, ADF&G, Area Management Biologist for the Game Division in Kodiak and through a meeting with Larry Matfay, the big game guide for the Old Harbor area. Big Creek, the larger stream which Midway Creek joins at the mouth, is heavily used by bears throughout the year. Denning is known to occur in the higher areas (above 50 0 feet) to the west and north of Old Harbor, including the Big Creek drainage, and it probably occurs in the upper reaches of Midway Creek as well. In spring, bears commonly feed below 500 feet along the south- facing slopes paralleling Big Creek including the portion which extends to Bush Point. The lower elevations of Big Creek and Midway Creek are also good deer wintering areas. to Uyak Bay in 1952 and 1953 Mountain goats were introduced (Burris et al., 1973) and they -10- have since extended their range southwesterly to include the higher portions of the Big Creek drainage. Big Creek has a good beaver population. Land otter util- ize the tidally influenced area but do not seem to use the upper reaches as extensively. Bald eagles are resident in the Big Creek area. U.S. Fish and Wild life Service records show one eagle nest on Midway Creek delta (Zwiefelhofer, 1981). Two additional eagle nests were located on the t.fidway Creek delta during DOWL field studies and a sharp-shinned hawk was observed flying across Midway Creek. Waterfowl nesting occurs in the Big Creek drainage in association with the numerous beaver ponds and wetlands. This drainage is also used by migrant and wintering waterfowl. Big Creek is good winter habitat for diving ducks, with goldeneyes, harlequins and buffleheads utilizing the river, and scoters, eiders, and oldsquaws in the offshore areas. Species lists of mammals and birds of the Kodiak Island Archipelago are given in Tables 3 and 4. J. CURRENT UTILIZATION OF WILDLIFE RESOURCES Most of deer hunting by local residents occurs on Sitkali- dak Island, Barling Bay, or north of Old Harbor on Kodiak Island. The annual harvest by Old Harbor residents probably does not exceed 150 deer (Smith, 1981). Red fox, beaver, and river otters are trapped by a few local residents. Only 12 river otters were reported harvested in 1981 from the Old Harbor area. No harvest figures are kept by ADF&G on red fox, but probably no more than 25 to 50 animals are taken annually in the Old Harbor area. Little trapping occurs for beaver as prices are low at present. The above -11- figures are taken from correspondence of October 20, 1981, with Roger Smith. The Big Creek area is commonly used by local residents for waterfowl hunting. K. ENDANGERED SPECIES No endangered species or subspecies occur on Kodiak Island (Money, 1981). Peales peregrine falcon, the nonendangered sub- species, does nest on Kodiak Is land. Both endangered sub- species of peregrine falcons have been reported to winter on Kodiak Island, but this has not been verified. Peregrine falcons were trapped and observed by U.S. Fish and Wild! ife Service biologists during the winter of 1980-81, but they were all the nonendangered subspecies (Amaral, 1982). L. WILDLIFE IMPACTS Permanent wildlife habitat loss will result primarily from borrow sites and the construction of roads and fac i 1 i ties at the dam site. Temporary habitat alterations. will occur at equipment staging areas and access roads needed for installing the transmission line. The volume of habitat permanently altered will be minimal. The principal species affected will be aquatic mammals. Wildlife disturbance will result during construction from the operation of equipment and the presence of humans. This could result in the temporary displacement of species such as deer, mountain goats and raptors. Brown bears could be af- fected if improper handling of garbage or the presence of con- struction workers results in conflicts between bears and humans. Increased wildlife harvests may result from the pres- ence of construction personnel. -12- TABLE 3 TERRESTRIAL MAMMALS OF THE KODIAK ISLAND ARCHIPELAGO SPECIES Little Brown Bat Tundra Vole Red Fox Brown Bear Short-tailed Weasel River Otter Snowshoe Hare Arctic Ground Squirrel Norway Rat House Mouse Northern Red Squirrel* Marten* Beaver l1uskrat Roosevelt Elk* Sitka Black-tailed Deer Mountain Goat Dall Sheep INDIGENOUS INTRODUCED * Introduced to Afognak Island -13- SCIENTIFIC NAME Myotis luncifugus Microtus oeconomus Vulpes vulpes Ursus arctos r-tustela erminea Lutra canadensis Lepus americanus Citellus parryi Rattus norvegicus Mus musculus Tamiasciurus hudsonicus Martes americana Castor canadensis Ondatra zibethicus Cervus canadensis Odocoileus hemionus Oreamnos americanus Ovis dalli TABLE 4 BIRDS OF THE KODIAK ISLAND ARCHIPELAGO A -Abundant C -Common U -Uncommon R -Rare + -Casual * -Nesting SPECIES Common Loon Yellow-billed Loon Arctic Loon Red-throated Loon Red-necked Grebe Horned Grebe Short-tailed Albatross Black-footed Albatross Laysan Albatross Northern Fulmar Pink-footed Shearwater Flesh-footed Shearwater New Zealand Shearwater Sooty Shearwater Short-tailed Shearwater Manx Shearwater Scaled Petrel Fort-tailed Storm-petrel Leach's Storm-petrel Double-crested Cormorant Pelagic Cormorant Red-faced Cormorant Great Blue Heron S-Spring, March-May S -Summer, June-August F -Fall, September-November W-Winter, December-February SCIENTIFIC NAME s s Gavia immer u u Gavia adamsii R --- Gavia arctic a u Gavia stellata u u Podiceps grise~ena u + Podice_es auritus u Diomede a albatrus + + Diomede a nigripes c c Diomedea immutabilis u u Fulmaris ~lacialis c c Puffinus creato_eus + Puffin us carneipes + + Puffin us bulleri + + Puffin us grise us A A Puffin us tenuirostris A A Puffin us puffin us + Pterodroma inex_eectata u u Oceanodroma furcata c c Oceanodroma leucorhoa u u Phalacrocorax auritus u u Phalacrocorax _eelagicus c c Phalacrocorax urile c c Ardea herodias + + -14- F w u u R u u u u u u u u u c u c c A u A u u c c u u c c c c u + + SPECIES Whistling Swan Canada Goose Brant Emperor Goose White-fronted Goose Snow Goose Mallard Spotbill Duck Gadwall Pintail Green-winged Teal Blue-winged Teal Northern Shoveler European Wigeon American Wigeon Canvasback Redhead Ring-necked Duck Greater Scaup Lesser Scaup Tufted Duck Common Goldeneye Barrow's Goldeneye Bufflehead Oldsquaw Harlequin Duck Steller's Eider Common Eider King Eider Spectacled Eider White-winged Scoter TABLE 4 Continued SCIENTIFIC NAME Olor columbianus Brant a canadensis Branta bernicla Philacte canagica Anser albifrons --- Chen caerulescens Anas platyrhynchos ~ poecilorhyncha An as strepera An as acuta An as crecca An as discors An as clypeata Anas penelope Anas americana Aythya valisineria Aythxa americana Aythya collar is AJ::thxa rnarila Aythya affinis AJ::thya americana Bacephala clangula Bucephala islandica Bucephala albeola Clangula hyernalis Histrionicus histrionicus Polysticta stelleri Sornarteria rnollissirna Sornateria spectabilis Sornateria fischeri Melanitta deglandi -15- s s F w c c c R u u + A + + + c u c u u + A A A A + u u u u A c c u c c c u R c R R + u R R c c c u + + + + + + R R R A c A A R R R + + c u c c c u c c c + c c A + A A A c A A c + u c u u u u c R u c + A u A A SPECIES Surf Seater Black Seater Hooded Merganser Smew Common Merganser Red-breasted Merganser Goshawk Sharp-shinned Hawk Rough-legged Hawk Golden Eagle Bald Eagle Steller's Sea Eagle Marsh Hawk Osprey Gyrfalcon Peregrine Falcon Merlin American Kestrel Willow Ptarmigan Rock Ptarmigan Sandhill Crane Black Oystercatcher Semi-palma ted Plover Killdeer American Golden Plover Black-bellied Plover Hudsonian Godwit Bar-tailed Godwit Marbled Godwit Whimbrel Bristle-thighed Curlew TABLE 4 Continued SCIENTIFIC NAME Melanitta perspicillata Melanitta nigra Lophodytes cucullatus Mergus albellus Mergus merganser Mer~us serrator Accipiter gentilis Accipiter striatus Buteo lagopus Aquila chrysaetos Haliaeetus leucocephalus Haliaeetus 12elagicus Circus cyaneus Pandion haliaetus Falco rusticolus Falco ---pereginus Falco columbarius Falco ---sparverius Lag opus lagopus Lag opus mutus Grus canadensis Haematopus bachmani Charadrius semipalmatus Charadrius vociferus Pluvialis dominic a Pluvialis squatarola Limos a haemastica Limos a lapponica Limos a fedoa Numenius J2haeopus Numenius tahitiensis -16- s s F w c R c c A [J A A + + R R + c c c ,.., '-- c c c c c ,.., c c '-- u u u u u c u + u u u u c c c c + u R u R + + R R R c u c c R R u R + + c c c c c c c c + c c c c A A [J + c u c c u u + R + R u R + + SPECIES Greater Yellowlegs Lesser Yellowlegs Solitary Sandpiper Spotted Sandpiper Wandering Tattler Ruddy Turnstone Black Turnstone Northern Phalarope Red Phalarope Common Snipe Short-billed Dowitcher Long-billed Dowitcher surfbird Red Knot Sanderling Semi-palrnated Sandpiper Western Sandpiper Least Sandpiper Baird's Sandpiper Pectoral Sandpiper Sharp-tailed Sandpiper Rock Sandpiper Dunlin Stilt Sandpiper Buff-breasted Sandpiper Ruff Pomarine Jaeger Parasitic Jaeger Long-tailed Jaeger South Polar Skua Glaucous Gull TABLE 4 Continued SCIENTIFIC NAME Tringa melanoleuca Tringa flavipes Tringa solitaria Actitis macularia Heteroscelus incanus Arenaria interpres Arenaria melanocephala Phalaropus lobatus Phalaropus fulicarius Gallinago gallinago Limnodromus griseus Limnodromus scolopaceus Aphriza virgata Calidris canutus Calidris alba Calidris pusilla Calidris mauri Calidris minutilla Calidris bairdii Calidris melanotos Calidris acuminata Calidris ptilocnemis Calidris alpina Micropalama hirnantopus Tryngites subruficollis Philomachus pugnax Stercorarius pomarinus Stercorarius parasiticus Stercorarius longicaudus Catharacta maccormicki Larus hyperboreus -17- s c + R c R c c u c c + c + R R A R c c c c u R s c c + u c R c c u c c + u + R A A u u u R + + c c u + + F c c R u R u c u c u R u R u R R c c c u + + c c u R w u R u R + c u R SPECIES Glaucous-winged Gull Slaty-backed Gull Herring Gull Thayer's Gull Ring-billed Gull Mew Gull Bonaparte's Gull Black-legged Kittiwake Red-legged Kittiwake Sabine's Gull Arctic Tern Aleutian Tern Common Murre Thick-billed Murre Pigeon Guillemot Marbled Murrelet Kittlitz's Murrelet Ancient Murrelet Cassin's Auklet Parakeet Auklet Crested Auklet Least Auklet Rhinoceros Auklet Horned Puffin Tufted Puffin Morning Dove Snowy Owl Hawk Owl Short-eared Owl Boreal Owl Belted Kingfisher TABLE 4 Continued SCIENTIFIC NAME Larus glaucescens Larus schistisagus Larus argentatus ~ thayeri Larus delawarensis Larus canus Larus philadelphia Rissa tridactyla Rissa brevirostris Xema sabini Sterna paradisaea Sterna aleutica Uria aalge Uria lomvia Cepphus columba Brachyramphus marmoratus Brachyramphus brevirostris Synthliboramphus antiguus Ptychoramphus aleuticus Cyclorrhynchus psittacula Aethia cristatella Aethia pusilla Cerorhinca monoccrata Fratercula corniculata Lunda cirrhata Zenaida macrovra Nyctea scandia Surnia ulula flammeus Aegolius funereus Megaceryle alcyon -18- s A + R R + c u A + u c u c R c c R u u R + + R c A u u c c s A R c u A + u c u c R c c R u u R + + R c A + u u c c F A R R A u A + R A R c c R R u R c + R c A + + u u c c w A + R R A u + A R c c R R A + R R R + u R c c SPECIES Common Flicker Yellow-bellied Sapsucker Hairy Woodpecker TABLE 4 Continued SCIENTIFIC NAME Colaptes auratus Sphyrapicus varius Picoides villosus Downy Woodpecker Picoides pubescens Northern Three-toed Woodpecker Picoides tridactylus Eastern Kingbird Horned Lark Violet-green Swallow Tree Swallow Bank Swallow Barn Swallow Cliff Swallow Black-billed Magpie Common Raven Northwestern Crow Black-capped Chickadee Red-breasted Nuthatch Brown Creeper Dipper Winter Wren American Robin Varied Thrush He:r:mit Thrush Gray-cheeked Thrush Golden-crowned Kinglet Ruby-crowned Kinglet Water Pipit Bohemian Waxwing Northern Shrike Starling Orange-crowned Warbler Tyrannus tyrannus Eremophila alpestris Tachycineta thalassina Iridoprocne bicolor Riparia riparia Hirundo rustica Petrochelidon pyrrhonota Pica pica Corvus corax Corvus caurinus Parus atricapillus Sitta canadensis Certhia familiaris Cinclus mexicanus Tr29lodytes troglodytes Turdus migratorius Ixoreus naevius Catharus guttatus Catharus minimus Regulus satrapa Regulus canendula Anthus spinoletta Bombycilla garrulus Lanius excubitor Sturnus vulgaris Vermivora celata -19- s c u c c u c c c c u c c c R c A R A c c + c s + c u + c c A R + c c c c u c c c R c A c A + c c c F + + c u + R R u c c c c u c c c R c c A + c R c + R w + + c u c c c c u c c c R u A + + R c + SPECIES Yellow Warbler Yellow-rumped Warbler Blackpoll Warbler Wilson's Warbler Red-winged Blackbird Rusty Blackbird Brambling Pine Grosbeak Gray-crowned Rosy Finch Hoary Redpoll Common Redpoll Pine Siskin Red Crossbill White-winged Crossbill Savannah Sparrow Dark-eyed Junco Tree Sparrow Harris' Sparrow White-crowned Sparrow Golden-crowned Sparrow White-throated Sparrow Fox Sparrow Lincoln's Sparrow Song Sparrow Lapland Longspur Snow Bunting McKay's Bunting TABLE 4 Continued SCIENTIFIC NAME Dendroica petechia Dendroica coronata Dendroica striata Wilsonia pusilla Agelaius phoeniceus Euphagus corolinus Fringilla montifringilla Pinicola enucleator Leucosticte tephrocotis Carduelis hornemanni Carduelis flammea Carduelis pinus Loxia curvirostra Loxia leucoptera Passerculus sandwhichensis ~ hyemalis Spizella arborea Zonotrichia querula Zonotrichia levcophrys Zonotrichia atricapilla Zonotrichia albicollis Passerella iliaca Melospiza albicollis Melospiza melodia Calcarius lapponicus Plectrophenax nivalis Plectrophenax hyperboreus -20- s R R u R c u + c c R c A R u + R A A c A c s c u + A c u c c R c A + + A A c A c F R R u + R + c u c c R c A u u + R c + c + c c c w R c 0 c c R c + u u + R R R + c + c + If a barge landing and road to the powerhouse are used for access, project operation should have little impact on wild- life. Some minor mortality to birds may result from collisions with the transmission line, and water dependent animals such as the dipper may be forced to relocate due to the periodic de- watering of some stream sections. Local residents may use the road as a vantage point for deer hunting, and thus increase the harvest in the Big Creek/Midway Creek drainages. The potential increased harvest is expected to be small due to the short length of the road and the traditional use of other areas for hunting. M. WILDLIFE MITIGATION The proposed project is on such a small scale that most impacts such as disturbance of wildlife during construction will be minor and short term. To further minimize impacts, the following guidelines should be followed: No feeding of wildlife should occur and all refuse should be placed in metal containers with heavy lids and be removed regularly from the construction sites. If problems >'lith bears or other wildlife do arise, the appropriate Alaska Department of Fish & Game officials should be contacted and the handling of the problem should follow their recommendations. Hunting or fishing in the project area should not be permitted by the contractor or construc- tion workers during construction. -21- A 330-foot construction buf r zone should be established around active eagle nests. Restric- tions may include prohibiting helicopters and fixed-wing aircraft from coming within a 1,000- foot radius of the airspace surrounding those nests. N. VEGETATION The alluvial fan is dominated by cottonwood, with an asso- ciated understory of alder, devilsclub, and elderberry. Near saltwater and along the sides of the fan, the cottonwood com- muni ty grades into a grass meadow. Along the stream valley, extensive alder, elderberry and salmonberry thickets intermix with a grass meadow containing cowparsnip, fireweed and goats- beard. In higher elevations, the meadow community appears to dominate. 0. ARCHAEOLOGIC AND HISTORIC SITES An archaeologic site has been identified on the delta of Midway Creek, but the extent of the site is unknown (Dilli- plane, 19 81). The Division of Parks may recommend that an archaeological survey be done in this area before project con- struction begins. P. POTENTIAL VISUAL IMPACTS The transmission line will be the only aspect of the project which could be visible from the village. Very little of the project will be visible from boats passing through Sitkalidak Strait. The powerhouse and diversion weir will be screened from view by vegetation, but the transmission li:-te and lower road may be visible from saltwater. -22- Q. IMPACT ON RECREATIONAL VALUES Project construction should have little effect on recrea- tional values. Little recreational use is currently made of the Midway Creek drainage. Local residents may use three- wheeled vehicles on the road to the powerhouse, but since the vehicles will have to be brought in by boat and the road is so short, little use is expected. Hunters may use the road as a vantage point to spot game. R. AIR QUALITY During project construction, exhaust fumes from diesel equipment and dust generated by construction activity may af- fect air quality. Dispersion of air pollutants is expected to be adequate to prevent any significant effects to air quality in the area. Electrical power for Old Harbor is currently provided by diesel generators. Particulate emissions from the combustion of diesel fuel have a high proportion of particles with a very small size fraction. These smaller particles penetrate deeper into the lungs and are therefore more hazardous to health than emissions from the combustion of other hydrocarbon products. Replacement of the diesel generating facilities by hydro- electric power should lower the discharge of hydrocarbon pollu- tants. S. SOCIOECONOMIC IMPACTS No major socioeconomic impacts are anticipated during the construction period for the proposed hydropower facility. The Old Harbor population normally increases by as many as 60 peo- ple during the commercial fishing season, so locals are accus- tomed to influxes of people. The construction force and sup- -23- port personnel are not expected to exceed 21 people, and they will average 16. If accommodations are not available locally, as is likely, trailers will be brought in and a work camp will set up. Mobilization would probably begin about April 1, with actual work beginning about April 15. The project should be completed by September 31st of the same year. Working hours would be 10 hours a day, six or seven days a week until project completion. Skilled craft labor will be required. Although local hire will be considered, the local residents will not be hired un- less they have appropriate skills. Old Harbor residents may resent this. However, construction will occur during the sum- mer months, so many residents are likely to be busy with com- mercial fishing and not be available for hire. The potential does exist for alcohol-related problems be- tween villagers and construction personnel. Although Old Har- bor is not dry, there are no liquor outlets in town. Exper- ience has shown that alcohol is generally present in construc- tion camps. In toxic a ted workers could create problems for locals, and the reverse is also true. The proximity of alcohol may also lead to the purchase or barter (particularly for local products) of alcohol from construction workers by local resi- dents. The availability of hydropower may provide economic bene- fits to the village and individual families. Cheaper electric bills should benefit the householders. Residents may elect to switch from oil heat to electric heat, which will require a large, initial cash output for conversion. Maintenance of the power generation equipment will provide periodic employment for a skilled resident. -24- T. LAND STATUS The diversion weir, penstock and powerhouse locations of the proposed hydroelectric project are entirely within lands of interim conveyance to Koniag, Incorporated, as provided for in the Alaska Native Claims Settlement Act of December 1971 (ANCSA), Public Law 92-203. This interim conveyance includes both surface and subsurface estates. Interim conveyance is used in this case to convey unsurveyed lands. Patent wi 11 follow interim conveyance once the lands are identified by survey. The proposed construction site of a barge landing in Mid- way Bay near the mouth of Big Creek and the road construction site from the landing to the powerhouse are also located on lands with an interim conveyance classification to Koniag, Incorporated. The transmission route from the powerhouse across Big Creek delta to the townsite of Old Harbor, u.s.s. 4793, is also similarly classified. Old Harbor has a federal townsite, u.s.s. 4793, with the patent issued to the Bureau of Land Management Townsite Trust- ee. The Trustee has deeded occupied parcels to the resident and some vacant subdivided lots to the City of Old Harbor. Other subdivided property remains with the Trustee. A permit would be required for the transmission line and may be issued by the u.s. Department of Interior after an affirmative resolu- tion by the city council. The extent of the impacts and the easements required on these lands is dependent upon the final transmission route within u.s.s. 4793. All of the interim conveyed lands identified above are also oart of the Kodiak National Wildlife Refuge as classified .. and withdrawn by Public Land Orders 1634, 5183 and 5184. All lands that were part of a National Wildlife Refuge before the -25- passage of ANCSA and have since been selected and conveyed to a Native corporation will remain subject to the laws and regula- tions governing use and development of such refuges. U. PERrHTTING REQUIREr1ENTS The following permits will be required for construction of the Old Harbor facility: Under the authority of Section 404 of the Fed- eral Water Pollution Control Act Amendments of 1972, the Army Corps of Engineers (COE) must authorize the discharge of dredged or fill mate- rials into navigable waters, which includes adjacent wetlands, by all individuals, organi- zations, commercial enterprises, and federal, state and local agencies. A COE Section 404 Permit will therefore be required for the diver- sion weir on Midway Creek. A Water Quality Certificate from the State of Alaska, Department of Environmental Conservation (DEC), is also required for any activity which may result in a discharge into the navigable waters of Alaska. Application for the certifi- cate is made by submitting to DEC a letter re- questing a certificate, accompanied by a copy of the permit application being submitted to the Corps of Engineers. All public or private entities (except Federal agencies) proposing to construct or operate a hydroelectric power project must have a license from the Federal Energy Regulatory Commission (FERC) if the proposed site is located on a nav- -26- igable stream, or on u.s. lands, or if the pro- ject affects a u.s. government dam or interstate commerce. A Permit to Construct or r-todify a Dam is re- quired from the Forest, Land, and Water Manage- ment Division of the Alaska Department of Nat- ural Resources for the construction, enlarge- ment, alteration or repair of any dam in the State of Alaska that is ten feet or more in height or stores 50 acre-feet or more of water. A Water Rights Permit is required from the Director of the Division of Forest, Land and Water Management, Alaska Department of Natural Resources for any person who desires to appro- priate waters of the State of Alaska. However, this does not secure rights to the water. When the permit holder has commenced to use the appropriate water, he should notify the direc- tor, who will issue a Certificate of Appropria- tion which secures the holders' rights to the water. The proposed project area is located within the coastal zone. Under the Alaska Coastal Manage- ment Act of 1977, a determination of consistency with Alaska Coastal Management Standards must be obtained from the Division of Policy Development and Planning in the Office of the Governor. This determination would be made during the COE 404 Permit review. Any party wishing to use land or facilities of any National Wildlife Refuge for purposes other -27- than those designated by the manager-in-charge and published in the Federal Register must ob- tain a Special Use Permit from the U.S. Fish & Wildlife Service. This permit may authorize such activities as rights-of-way; easements for pipelines, roads, utilities, structures, re- search projects; entry for geologic reconnais- sance or similar projects, filming and so forth. Note that all lands that were part of a National Wildlife Refuge before the passage of the Alaska Native Claims Settlement Act, and have since been selected and conveyed to a Native corpora- tion will remain under the rules and regulations of the refuge. V. RECOMMENDATIONS Although full-scale environmental field studies were not undertaken, due to the small scale of the project and the lack of major fishery or wildlife resources in the affected area, these studies were considered sufficient to assess potential impacts to the area. Therefore, unless substantial additional concerns are expressed by local residents or regulatory agen- cies, no additional environmental studies are considered necessary. ~~. REFERENCES CITED Alaska Department of Fish & Game. 1978. Alaska's Fisheries Atlas, Volumes I and II. Alaska Department of Fish & Game. 1968, revised 1975. Cata- logue of Waters Important for Spawning and Migration of Anadromous Fishes. -28- Burris, 0. E., and D. E. McKnight. 1973. Game Transplants in Alaska, ADF&G Game Technical Bulletin No. 4. X. PERSONAL COMMUNICATIONS Amaral, Michael. Wildlife Biologist, U.s. Fish and Wildlife Service, Endangered Species. 1982. Dilliplane, Ty. Alaska Department of Natural Resources, Divi- sion of Parks. 1981. Manthey, Ken. Fisheries Biologist, Commercial Fish Division, Kodiak, Alaska. 1981. ~1a tfay, Larry. Old Harbor Big Game Guide. 19 81. Money, Dennis. u.s. Fish and Wildlife Service, Endangered Species. 1981. Smith, Roger. Game Biologist, Game Division, ADF&G, Kodiak, Alaska. 1981. Zwiefelhofer, Denny. U.S. Fish and Wildlife Service, Kodiak National Wildlife Refuge. 1981. -29- OLD HARBOR HYDROELECTRIC PROJECT FEASIBILITY STUDY APPENDIX F LETTERS AND MINUTES • Minutes of the public hearings held in connection with the Old Harbor Project will be presented in the final draft of this report along with copies of relevant letters from agencies and other interested parties. NBI-419-9524-F