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Home My WebLink AboutChakachamna Hydroelectric Project Interim Feasibility Assessment Report Vol.1 1983CHAKACHAMNA HYDROELECTRIC PROJECT INTERIM FEASIBILITY ASSESSMENT REPORT VOLUME I SECTIONS 1-10 APPENDIXES TO SECTIONS 4.0 & 8.0 L n·-~. u~ BE CHTEL CIVIL & MINERALS INC . ENGINEERS -CONSTRUCTORS pROPERTY OF: Alasl<a power Authority 334 W 5th AYJe. . k 99501 Ancnorage, A\as a MARCH 1983 y ..__ALASKA POWER AUTHORITY_~ = -"""--"""" I VTnNCBINIWd sao H!JPISHt)tH I 1 l 0.1031n9SI 31.1VO l • A ~00 VHJ CHAKACHAMNA HYDROELECTRIC PROJECT INTERIM FEASIBILITY ASSESSMENT REPORT VOLUME I SECTIONS 1-10 APPENDIXES TO SECTIONS 4.0 & 8.0 BECHTEL CIVIL & MINERALS INC. ENGINEERS-CONSTRUCTORS MARCH 1983 ..____ALASKA POWER AUTHORITY __ ___. section ALASKA POWER AUTHORITY ANCHORAGE, ALASKA CHAKACHAMNA HYDROELECTRIC PROJECT INTERIM FEASIBILITY ASSESSMENT REPORT MARCH 1983 VOLUME .r TABLE OF CONTENTS 1.0 INTRODUCTION 2.0 SUMMARY 2.1 Project Layout Studies 2.2 Geological Studies 2.3 Environmental Studies 2. 3 .1 2.3.2 2.3.3 2.3.4 Hydrology Aquatic Biology Terrestrial Biology Human Resources 2.4 Economic Evaluation 2. 5 Technical Evaluation ar1d Discussion 2.5.1 2.5.2 2.5.3 2.5.4 Chakachatna Dam Alternative McArthur Tunnel, Alternatives A & B Chakachatna Tunnel, Alternatives C & Alternative E 3.0 PROJECT DEVELOPMENT STUDIES 3.1 Regulatory Storage 3.2 Chakachatna Dam 3.3 McArthur Tunnel Development 3.3.1 3.3.2 Alternative A Alternative B 3.4 Chakachatna Tunnel Development 3.4.1 3.4.2 Alternative C Alternative D 3.5 McArthur Development-Recommended Alternative E 3.5.1 3.5.2 General Water Releases and Fish Passage Facilities i Page 1-1 2-1 2-1 2-3 2-5 2-5 2-6 2-7 2-8 2-10 2-11 2-ll 2-11 D 2-13 2-14 3-1 3-1 3-2 3-4 3-4 3-18 3-19 3-19 3-25 3-26 3-26 3-28 Section 3.5 McArthur Development-Recommended Alternative (cont'd) 3. 5. 3 3.5.4 3.5.5 3.5.6 Upstream Migrants Facility Downstream Migrants Facility Conveyance Channel Outlet Structure 3.6 Transmission Line and Submarine Cable 3.7 References 4.0 HYDROLOGICAL AND POWER STUDIES 4.1 Introduction 4.2 Historical Data 4.3 Derived Lake Inflows 4.4 synthesis of Long-Term Lake Inflows 4.5 Power Studies 4.6 Results 4.7 Variations in Lake Water Level 5.0 GEOLOGIC INVESTIGATIONS 5.1 Scope of Geologic Investigations 5 .1.1 Technical Tasks 5 .1. 2 5.1.1.1 5.1.1.2 5.1.1.3 5.1.1.4 5.1.1.5 I Schedule 5.1.2.1 5.1.2.2 5.1.2.3 5.1.2.4 5.1.2.5 5.2 Quaternary Geology Quaternary Geology Seismic Geology Tunnel Alignment and Power Plant Site Geology Construction Materials Geology Road and Transmission Line Geology Quaternary Geology Seismic Geology Tunnel Alignment and Power Plant Site Geology Construction Materials Geology Road and Transmission Line Geology ii Page E 3·-31 3-32 3-39 3-39 3-43 3-44 4-1 4-1 4-2 4-3 4-4 4-16 4-19 4-23 5-l 5-l 5-l 5-2 5-4 5-"6 5-6 5-7 5-7 5-7 5-8 5-8 5~9 5-9 5-9 Section- 5.2.1 5.2.2 5.2.3 Glaciers and Glacial Geology 5.2.1.1 5.2.1.2 5.2.1.3 5.2.1.4 5.2.1.5 5.2.1.6 Regional Glacial Geologic History Project Area Glacial Geologic History Barrier Glacier Blockade Glacier Other Glaciers Implications with Respect to Proposed Hydroelectric ProJect Mt. Spurr Volcano Alaska Peninsula-Aleutian Pase 5-10 5-10 5-14 5-20 5-30 5-36 5-39 5-40 5.2.2.1 5.2.2.2 5.2.2.3 Island Volcanic Arc 5-40 Mt. Spurr 5-42 Implications with Respect to Proposed Hydroelectric Project 5-49 Slope Conditions 5-51 5-51 5-52 5-54 5.2.3.1 5.2.3.2 5.2.3.3 5.2.3.4 Chakachamna Lake Area Chakachatna River Valley McArthur River Canyon Implications with Respect to Proposed Hydroelectric Project 5-55 5.3 Seismic Geology 5-56 5.3.1 5.3.2 5.3.3 Tectonic Settiny Historic Seismicity 5-56 5-60 5.3.2.1 5.3.2.2 Regional Seismicity Historic Seismicity of the Project Study Area Fault Investigation 5-60 5-61 5-73 5.3.3.1 5.3.3.2 5.3.3.3 5.3.3.4 Approach 5-73 work to Date 5-74 Candidate Significant Features 5-81 Implications with Respect to Proposed Hydroelectric Project 5-94 iii section 5.4 References 6.0 ENVIRONMENTAL STUDIES -SUMNARY 7. 0 6.1 Environmental Studies -1981 6 .1.1 6 .1.2 6 .1. 3 6 .1.4 Environmental Hydrology Aquatic Biology Terrestrial Vegetation and Wildlife Human Resources 6.2 Environmental Studies -1982 6. 2 .1 6.2.2 Environmental Hydrology -1982 A":[uatic Biology 6.2.2.1 6.2.2.2 6.2.2.3 6.2.2.4 6.2.2.5 6.2.2.6 6.2.2.7 Sockeye Salmon Chinook Salmon Pink Salmon Chum Salmon Coho Salmon Dolly Varder1 Rainbow Trout EVALUATION OF ALTERNATIVES 7 .1 7.2 7.3 Engineering Evaluation 7 .1.1 General 7 .1. 2 Chakachatna Dam 7 .1. 3 Alternative A 7 .1. 4 Alternative B 7.1.5 Alternatives c and D 7 .1. 6 Alternative E Geological Evaluation 7.2.1 Chakachatna Dam 7.2.2 Alternative A 7.2.3 Alternative B 7.2.4 Alternatives c and D 7.2.5 Alternative E Environmental Evaluation 7.3.1 7. 3. 2 7.3.3 7.3.4 Chakachatna Dam Alternative McArthur Tunnel Alternatives A and Chakachatna Tunnel Alternatives C and D Recommended McArthur Tunnel Alternative E iv B 5-95 6-1 6-1 6-1 6-3 6-6 6-8 6-10 6-10 6-11 6-13 6-15 6-21 6-22 6-22 6-24 6-24 7-1 7-1 7-1 7-2 7-2 7-4 7~6 7-7 7-8 7-9 7-ll 7-11 7-12 7-14 7-14 7-15 7-20 7-23 section 7.3.4.1 7.3.4.2 7.3.4.3 Potential Effects on Aquatic Biota 7.3.4.1.1 Construction of the Chakachamna Hydroelectric Project and 7-23 Related Facilities 7-24 7.3.4.1.2 Operation of the Chakachamna Hydro- electric Project and Related Facilities 7-32 7.3.4.1.3 summary of Potential Effects 7-52 Potential E£fects on Botanical Resources 7.3.4.2.1 Direct Habitat 7-55 Loss 7-55 7.3.4.2.2 Indirect Habitat Alteration 7-56 7.3.4.2.3 summary of Potential Effects 7-58 Potential Effects on Wildlife Resources and Habitats 7-59 7.3.4.3.1 Direct Habitat Loss 7-61 7.3.4.3.2 Indirect Habitat Alteration 7-61 7.3.4.3.3 summary of Potential Effects 7-65 7.4 Project Risk Evaluation 7-68 7.4.1 7.4.2 7.4.3 7.4.4 7.4.5 7.4.6 7.4.7 7.4.8 Lake Ta?ping Tunnel Alignment Rock Conditions Underground Powerhouse Site Barrier Glacier Blockade Glacier McArthur Glacier Mt. Spurr Volcano Seismic Risk v 7-68 7-69 7-71 7-71 7-73 7-74 7-7 4 7-78 Section 7.4.9 7 .4.8.1 7.4.8.2 Lake Clark-Castle Mountain Fault Bruin Bay Fault Faults in Chakachatna Valley 7.5 References 8.0 CONSTRUCTION COSTS AND SCHEDULES 8.1 Estimates of Cost 8 .1.1 8 .1. 2 8 .1. 3 8 .1.4 8 .1. 5 8 .1. 6 Power Tunnel Underground Powerhouse and Associated Structures Tailrace Channel switchyard Transmission Line and Cable Crossing Site Access aud Development 8.2 Exclusions from Estimates 8.3 Construction Schedules 9.0 ECONOMIC EVALUATION 9.1 General 9.2 Parameters for Economic Evaluation 9.3 Cost of Power from Alternative Sources 9.3.1 9.3.2 9.3.3 9.3.4 General Constructiou Cost Operation and Maintenance Cost Fuel Cost 9.4 Value of Hydro Generation 9.5 Economic Tunnel Sizing 9.6 Economic Tunnel Length 10.0 COORDINATION 10.1 Introduction 10.2 Human Resources 10.2.1 10.2.2 Meeting, December 10, 1981 Response 10.3 Biological Studies 10.3.1 Meeting, December 11, 1981 10.3.1.1 Response vi 7-78 7-79 7-80 7-80 8-1 8-1 8-6 8-9 8-10 8-11 8-11 8-11 8-16 8-16 9-1 9-1 9-2 9-2 9-2 9·-3 9-4 9-4 9-6 9-12 9-15 10-1 10-1 10-1 10·-1 10-4 10-4 10-4 10-10 Section 10.3.2 10.3.3 Correspondence U.S. Fish and Wildlife Service APA Response Alaska Department of Fish and Game APA Response National Marine Fisheries Service APA Response Meeting, December 9, 1982 Response by National Marine Fisheries Service Response by u.s. Fish and Wildlife Service 10.4 National Park Service 10.4.1 Lake Clark National Park 10.5 Northern Alaska Environmental Center 10.5.1 Correspondence 10.5.1.1 Response APPENDIXES Appendix to Section 4.0 Appendix to Section 8.0 vii 10-10 10-21 10-23 10-34 10-35 10-38 10-39 10-49 10-51 10-54 10-54 10-58 10-58 10-58 Table 2.1 4.1 4. 2 4.3 4.4 4.5 4.6 6.1 6.2 6. 3 7.1 7.2 7.3 7.4 VOLUME I LIST OF TABLES Project Data, Alternative E Lake Chakachamna Inflows Inflows to the Lake in CFS Monthly Peak Power Demands Used in Power Studies Provisional Minimum Releases for Instream Flow in Chakachatna River Downstream from Chakachamna Lake outlet for Use in Power studies Power Plant System Constraints for Alternative Project Developments Power Studies summary Species List and Drainage of Occurrence August-September 1981 Species Composition and Relative Abundance of Mammals Identified Within the Study Area for Each of the Habitat Types summary of Estimated Salmon Escapement by Waterbody and Drainage for 1982 Cost of Energy Natural and Alternative B Regulated Mean Monthly and Mean Annual Flow at the Chakachamna Lake Outlet Natural and Alternative D Regulated Mean Monthly and Mean Annual Flows at the Chakachamna Lake Outlet Natural and Alternative E Regulated Mean Monthly and Mean Annual Flow at the Chakachamna Lake outlet viii Pa52e 2-16 4-11 4-15 4-17 4-18 4-20 4-21 6-4 6-7 6-14 7-3 7-18 7-22 7-40 Table 7.5 7.6 9.1 9.2 9.3 Estimated Escapement of Important Fish Species in the Chakachatna River Slstem by Waterbody classified by Potential Effects of Decreased Flow of Water from Chakachamna Lake Estimated Escapement of Important Fish Species in the McArthur River System by Waterbody classified by Potential of Increased Flow of Water New Contract Gas Price (AML&P)-Anchorage Coal Fired Plant, Cost of Generatiny Power at 50% Load Factor Sheet 1 of 2 Sheet 2 of 2 Combined Cycle Plant, Cost of Generatiny Power at 50% Load Factor Sheet 1 of 2 Sheet 2 of 2 ix 7-43 7-49 9-5 9-8 9-9 9-10 9-11 Fisure No. 1-1 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 3-11 3-12 3-13 4-1 4-2 4-3 4-4 4-5 5-l VOLUME I LIST OF FIGURES · Title Location Map McArthur Tunnel, Alternative A-1 McArthur Tunnel, Alternatives A-2 & E Chakachatna Tunnel, Alternatives c & D Gate Shaft Section, Sheet 1 Gate Shaft Sections, Sheet 2 McArthur Power Development, General Arrangement Chakachatna Power Development, General Arrangement Chakachamna Lake Outlet, General Arrangement Upstream Fish Passage Facilities, Plans and Section Upstream Fish Passage Facilities, Sections Downstream Fish Passage Facilities, Instream Release Structure Outlet Fish Passage Facilities, Plan and Sections Transmission Line, Route Location Hydrometeorological Station Locations Hydrometeorological Stations, Periods of Record Chakachamna Lake, Stage -Area and Storage Alternatives A and B -Lake Level Variations Alternatives C and D -Lake Level Variations Quaternary Geology Site Locations X Figure No. 5-2a 5-2b 5-3 5-4 5-5 5-6 5-7 5-8 5-9 8-1 8-2 8-3 8-4 9-1 9-2 9-3 Title Glacial and Volcanic Features in the Chakachamna -Chakachatna Valley Glacial and Volcanic Features in the Chakachamna -Chakachatna Valley Plate Tectonic Map Major Earthquakes and Seismic Gaps in Southern Alaska Historic Earthquakes of all Focal Depths in the Site Region from 1929 through 1980 Historic Earth~uakes of Focal Depth Greater than 20 Miles in the Site Region from 1929 through 1980 Historic Earthquakes of Focal Depth Less than 20 Miles in the Site Region from 1929 through 1980 Seismic Geology Investigation Sequence Map Showing Locations of Candidate Significant Features in the Project Study Area Access Roads Project Schedule, Alternatives A and B Project Schedule, Alternatives C and D Project Schedule, Alternative E Economic Tunnel Diameter McArthur Tunnel Economic Length Chakachatna Tunnel Economic Length xi INTRODUCTION 1.0 ALASKA POWER AUTHORITY ANCHORAGE ALASKA CHAKACHAMNA HYDROELECTRIC PROJECT INTERIM FEASIBILITY ASSESSMENT REPORT, MARCH, 1983 INTRODUCTION This report has been prepared in accordance with the terms of Contract 82-0294 dated August 3, 1981 between the State of Alaska/Departmen.t of Commerce and Economic Development/Alaska Power Authority and Bechtel Civil & Minerals, Inc. in connection with services for performing interim feasibility assessment studies of the Chakachamna Hydroelectric Project. As its title indicates, the report is of an interim nature. It is based upon previously published information regarding the project, and on data acquired and derived during a study period extending from the fall of 1981 to December 1982. Its objectives are to summarize the information derived from the studies, to provide a preliminary evaluation of alternative ways of developing the power potential of the project, to define that power potential, and to report on the estimated cost of construction, and to provide a preliminary assessment of the effects that the project would have on the environment. The initial engineering, geological, and environmental studies were conducted during the fall of 1981, and the findings of these studies were summarized in an interim report dated November 30, 1981. Although the data 1-1 collected and study period up to that time were rather limited by the short time base, some rather clear indications emerged as to the manner in which it was considered that development of the project should proceed. One aspect that became evident was that a much more extensive and populous fishery uses the waters in the project area than had been earlier realized or anticipated. This led to an amendment of the above mentioned contract in which the requirements for completion of the feasibility report and application to the Federal Energy Regulatory Commission for a license to construct the project were deleted from the scope of work. Continuing studies of the fishery in the waters of the project area were authorized as were the development of conceptual designs for fish passage facilities at the outlet of Chakachamna Lake plus the preparation of estimates of their construction costs and those of the McArthur tunnel assuming that it could be excavated by tunnel boring machine. As may be seen by reference to Figure 1-1, Chakachamna Lake lies in the southern part of the Alaska Range of mountains about 85 miles due west of Anchorage. Its water surface lies at about elevation 1140 feet above mean sea level. The project has been studied and reported upon several times in the past. The power potential had been estimated variously from about 100,000 kw to 200,000 kw firm capacity, depending on the degree of regulation of the outflow from Chakachamna Lake and the hydraulic head that could be developed. l-2 Two basic alternatives can be readily identified to harness the hydraulic head for the generation of electrical energy. One is by a twelve mile tunnel more or less parallel to the valley of the Chakachatna River. This river runs out of the easterly end of the lake and descends to about elevation 400 feet above sea level where the river leaves the confines of the valley and spills out onto a broad alluvial flood plain. A maximum hydrostatic head of about 740 feet could be developed via this alternative. The other alternative is for development by diversion of the lake outflow through a ten mile tunnel to the valley of the McArthur River which lies to the southeast of the lake outlet. A maximum hydrostatic head of about 960 feet could be harnessed by this diversion. Various means of development by these two basic alternatives are discussed in the report on the basis of the present knowledge of the site conditions. The 1982 environmental studies confirmed the importance of the fishery using waters in the project area and expanded the data base concerning it. The basic elements of the recommended mode of development were conceived, these being for development via the McArthur River with a concrete lined machine bored tunnel and with fish passage facilities that would permit fish to ascend into the lake or to travel downstream from the lake into the Chakachatna River. Three samples of rock collected from the surface, two from the general vicinity of the proposed power intake site at Chakachamna Lake and one from near the powerhouse site by the McArthur River, were tested in The Robbins Company laboratory at Kent, Washington. The results indicated that the rock sampled, 1-3 would be suitable for boring, but since the test data from samples taken at the surface can sometimes be misleading, and since no geological studies have yet been performed along the planned t~nnel alignment, it must be assumed at the present time that the tunnel can be bored and additional geological studies will be needed before it can be firmly recommended that the tunnel be bored by machine. The rock test data was used for guidance in estimating the cutter penetration rate in assessing the estimated cost of excavating the tunnel by boring machine. For the assessment of environmental factors and geological conditions in the project area, Bechtel retained the services of Woodward-Clyde Consultants. 1-4 ~ •' ,. .. "' .., ~ + + ~ " c.o• VICIIVITY .MAP 4 0 4 6 SCALE t"-4 MILES AIOT ES : 1.) TOPOGRAPI('f 15 f'~OM 1/SGS QUAO~AA..IGL€ MAPS .... Z.)VERT!CA L O ATUM 15 MEA A..I LOWER LOW NATER 3.) HORIZOA..ITAL GR/0 15 WJIVERSAL TRANS VERSE M ERCATOR PROJECT/OAJ, t 9Z7 A./ORTH AME:R I CI!/..1 DATUM SUMMARY 2.0 SUMMARY 2.1 Project Layout Studies The studies evaluated the merits of developing the power potential of the project by diversion of water southeasterly to the McArthur River via a tunnel about 10 miles long, or easterly down the Chakachatna Valley either by a tunnel about 12 miles long or by a dam and tunnel development. In the Chakachatna Valley, few sites, adverse foundation conditions, and the nearby presence of an active volcano made it rapidly evident that the feasibility of constructing a dam there would be questionable. The main thrust of the initial studies was therefore directed toward the tunnel alternatives without consideration of raising the lake level above the present outlet channel invert, taken as El. 1128, and a minimum drawdown of the water level to El. 1014. Two alignments were studied for the McArthur Tunnel. The first considered the shortest distance that gave no opportunity for an additional point of access during construction via an intermediate adit. The second alignment was about a mile longer, but gave an additional point of access, thus reducing the lengths of headings and also the time required for construc- tion of the tunnel. Cost comparisons and economic evaluation nevertheless favored the shorter 10 mile 25 foot diameter tunnel. The second alignment running more or less parallel to the Chakachatna River in the right {southerly) wall of the valley afforded two opportunities for intermediate 2-1 access adits. These, plus the upstream and downstream portals would allow construction to proceed simulta- neously in 6 headings and reduce the construction time by 18 months less than that required for the McArthur Tunnel. Economic evaluation again favored a 25 foot diameter tunnel running all the way from the lake to the downstream end of the Chakachatna Valley. If all the controlled water were used for power generation, the McArthur Powerhouse could support 400 MW installed capacity, and produce average annual firm energy of 1752 GWh. The effects of r.1aking a provi- sional reservation of approximately 19% of the average annual inflow to the lake for instream flow require- ments in the Chakachatna River were found to reduce the economic tunnel diameter to 23 feet. The in- stalled capacity in the powerhouse would then be re- duced to 330 MW and the average annual firm energy to 1446 Gvih. If a small rock dike were to be constructed at the outlet of the lake and the maximum lake level is raised to the natural maximum, El. 1155, this would allow 72 feet lake drawdown to accommodate fish passage facilities. If the tunnel diameter remained 23 feet to avoid excessive losses, then the installed capacity in the powerhouse would be 330 MW and the average annual firm energy 1301 GWh. The reduction in firm energy is due to the lesser volume of regulatory storage contained within the narrower range of lake level needed for gravity operation of the fish passage facilities. 2-2 For the Chakachatna Powerhouse, diversion of all the controlled water for power generation would support an installed capacity of 300 MW with an average annual firm energy generation of 1314 GWh. Provisional reservation of approximately 0.8% of the average annual inflow to the lake for instream flow require- ments in the Chakachatna River was regarded as having negligible effect on the installed capacity and average annual firm energy because that reduction is within the accuracy of the present study. The reasoning for the smaller instream flow releases considered in this alternative is discussed in Section 2.5.3. 2.2 Geological Studies At the present level of study, the Quarternary Geology in the Chakachatna and McArthur Valleys has been eval- uated and the seismic geology of the general area has been examined though additional work remains to be done next year. General observations as they may af- fect the project are as follows: The move of ice of the Barrier Glacier toward the river may be gradually slowing. However, no material change in the effect of the glacier on the control of the Chakachamna Lake outlet is anticipated. The condition of the Blockade Glacier facing the mouth of the McArthur Canyon also appears to be much the same as reported in the previous USGS studies. 2-3 There does not appear to be any reason to expect a dramatic change in the state of growth or recession of either of the above two glaciers in the foreseeable future. Surface exposures on the left (northerly) side of the Chakachatna Valley consist of a heterogeneous mix of volcanic ejecta and glacial and fluvial sediments which raise doubts as to the feasibility of damming Chakachatna River by a dam located downstream of the glacier. The rock in the right wall of the Chakachatna Valley is granitic, and surface exposures appear to indicate that it would be suitable for tunnel construction if that form of development of the project were found to be desirable. No rock conditions have yet been observed that would appear to rule out the feasibility of constructing a tunnel between the proposed locations of an intake structure near the outlet of Chakachamna Lake and a powerhouse site in the McArthur Valley. It must be noted, however, that in the vicinity of the proposed powerhouse location in the McArthur Canyon, the surface exposures indicate that rock quality apppears to improve significantly with distance upstream from the mouth of the canyon. The Castle Mountain fault, which is a major fault structure, falls just outside the mouth of the McArthur Canyon and must be taken into account in the seismic design criteria of any development of the 2-4 2.3 2.3.1 project whether it be via the McArthur or Chakachatna Canyons. Other significant seismic sources are the Megathrust Section of the Subduction Zone and the Benioff Zone. Environmental Studies Hydrology Field reconnaissances were conducted in Chakachamna Lake, several of its tributary streams, the Chakachatna and McArthur Rivers. Records of mean daily flows were initiated in mid-August 1982 at the site of the previously operated u.s. Geological Survey gage site and in the Upper McArthur River downstream from the powerhouse location. Data collected and developed are typical of glacial rivers with low flow in late winter and large glacier melt flows in July and August. The water level in Chakachamna Lake when measured in 1981 was elevation 1142 and is typical of the September Lake stage records in the 12 years preceding the major flood of August 1971. Lake bottom profiles were surveyed at the deltas of the Nagishlamina and Chilligan Rivers, and the Shamrock Glacier Rapids. Reaches of the McArthur and Chakachatna Rivers vary in configuration from mountainous through meandering and braided. All except the most infrequent large floods are mostly contained within the unvegetated flood plan. Sedimentation characteristics appear to be typically those of glacial systems with very fine suspended sediments and substantial bed load transport. 2-5 2.3.2 Aquatic Biology Field observations identified the following species in the waters of the project area: Resident: Rainbow trout Lake trout Dolly Varden Round Whitefish Pygmy Whitefish Anadrornous: Chinook salmon Churn salmon Coho salmon Eulachon Longfin smelt Artie grayling Slimy sculpin Ninespine stickleback Threespine stickleback Pink salmon Sockeye salmon Dolly Varden Rainbow smelt Bering cisco Salmon spawning in the Chakachatna River drainage and its tributaries occurs primarily in tributaries and sloughs. A relatively small percentage of the 1982 estimated escapement was observed to occur in rnainstem or side-channel habitats of the Chakachatna River. The largest salmon escapement in the Chakachatna drainage was estimated to occur in the Chilligan and Igitna Rivers upstream of Chakacharnna Lake. The escapement of those sockeye in 1982 was estimated to be approximately 41,000 fish, or about 70 percent of the escapement within the Chakachatna drainage. Chakachamna Lake is the major rearing habitat for these sockeye. It also provides habitat for lake trout, Dolly Varden, round whitefish, and sculpins. 2-6 2.3.3 In the McArthur River over 96 percent of the estimated salmon escapement occurred in tributaries during 1982. The estimated escapement of salmon of all species was slightly greater in the McArthur than the Chakachatna drainage. Other anadromous fish including eulachon, Bering cisco, longfin smelt and rainbow smelt have been found in the McArthur River. The contribution of salmon stocks originating in these systems to the Cook Inlet commercial catch is presently unknown. Although some commercial and subsistence fishing occurs, the extent to which the stock is exploited is also not known. Rearing habitat for juvenile anadromous and resident fish is found throughout both rivers, although the waters within the Chakachatna River canyon below Chakachamna Lake and the headwaters of the McArthur River do not appear to be important rearing habitat. There appears to be extensive movement of fish within and between the two drainages, ·and seasonal changes in distribution have also been noted. Terrestrial Biology On the basis of their structural and species composi- tions, eight types of vegetation habitats were deli- neated. These range from dense alder thickets in the canyons to vast areas of coastal marsh. The riparian communities are the most prevalent varying from rivers with emergent vegetation to those with broad flood plains scattered with lichen, willow and alder. 2-7 2.3.4 Evaluation of wildlife communities in the project area identified seventeen species of mammals. Moose, coyote, grizzly bear and black bear ranges occur throughout the area. Birds also are abundant, fifty-six species having been identified with the coastal marshes along Trading Bay containing the largest diversity. None of the species of plants, mammals and birds that were found are listed as threatened or endangered although in May 1981 it was proposed that the tule whitefronted goose, which feeds and may nest in the area, be considered for threatened or endangered status. Human Resources These studies were organized into the following six elements: Archaeological and historical resources Land ownership and use Recreational resources Socioeconomic characteristics Transportation Visual resources Many contacts were made with both State and Federal Agencies and native organizations, as well as a limited reconnaissance of the project area. 2-8 No known cultural sites have been identified and the field reconnaissance indicates that the proposed sites for the power intake and powerhouses have a low po- tential for cultural sites. Land owners in the area comprise federal, state, and borough agencies, Native corporations and private parties. Land use is related to resource extraction (lumber, oil and gas), subsistence and the rural resi- dential village of Tyonek. Recreational activity takes place in the project area, but with the exception of Trading Bay State Game Refuge, little data is available as to the extent or frequency with which the area is used. Regional data on population, employment and income characteristics are relatively good. Employment level and occupational skill data are limited and need to be developed together with information on local employ- ment preferences. Transportation facilities in the area are few and small in size. There are airstrips at Tyonek and on the shoreline at Trading Bay. A woodchip loading pier is located near Tyonek. Several miles of logging roads exist between Tyonek and the mouth of the Chakachatna Valley; many of these roads and bridges are being removed as timber activities are completed in specific areas. The Chakachatna River was bridged near its confluence with Straight Creek until 1982. There is no permanent road linking the project area with any part of the Alaska road system. 2-9 The project area's scenic characteristics and prox- imity with BLM lands, Lake Clark National Park and the Trading Bay State Game Refuge make visual resource management a significant concern. 2.4 Economic Evaluation The studies demonstrate that the project offers an ecomonically viable source of energy in comparison with the 55.6 mills/kWh which is the estimated cost of equivalent energy from a coal fired plant, apparently the most competitive alternative source. Taking that figure as the value of energy, the Chakachamna Hydro- electric Project could begin producing 400 MW at 50% load factor (1752 GWh) in 1990 at 37.5 mills/KWh if all stored water is used for power generation. If approximately 19 percent of the water is reserved for instream flow release to the Chakachatna River, the powerplant could still produce 330 MW at 50% load factor (1446 GWh) at 43.5 mills/KWh, which is still significantly more economical than the coal fired alternative. Assuming that the power tunnel were to be machine bored, if the maximum pool level of the lake is raised to El. 1155 and can be drawn down to El. 1083, the powerplant will produce 330 MW (1301 GWh) at 44.5 mills/KWh with 45% load factor. In all the cases above, the powerhouse would be located on the McArthur River. A powerhouse on the Chakachatna River as described in the report is barely competitive with the alternative coal fired source of energy. 2-10 2.5 Technical Evaluation and Discussion 2.5.1 2.5.2 Several alternative methods of developing the project were identified and reviewed in 1981. Based on the analyses performed in 1982, the most viable alternative has been identified for further study. That is Alternative E in which water would be diverted from Chakachamna Lake to a powerhouse located near the McArthur River. Chakachatna Dam Alternative The construction of a dam in the Chakachatna River Canyon approximately 6 miles downstream from the lake outlet, does not appear to be a reasonable alterna- tive. While the site is topographically suitable, the foundation conditions in the river valley and left abutment are poor as mentioned earlier in Section 2.2. Furthermore, its environmental impact specifically on the fisheries resource will be significant although provision of fish passage facilites could mitigate this impact to a certain extent. McArthur Tunnel Alternatives A, and B Diversion of flow from Chakachamna Lake to the McArthur Valley to develop a head of approximately 900 feet has been identified as the most advantageous as far as energy production at reasonable cost is concerned. The geologic conditions for the various project facil- ities including intake, power tunnel, and powerhouse appear to be favorable based on the limited 1981 field 2-11 reconnaissances. No insurmountable engineering pro- blems appear to exist in development of the project. Alternative A, in which essentially all stored water would be diverted from Chakachamna Lake for power production purposes could deliver 1664 GWh of firm energy per year to Anchorage and provide 400 MW of peaking capacity. Cost of energy is estimated to be 37.5 mills per KWh. However, since the flow of the Chakachatna River below the lake outlet would be adversely affected, the existing anadromous fishery resource which uses the river to gain entry to the lake and its tributaries for spawning, would be lost. In addition the fish which spawn in the lower Chakachatna River would also be impacted due to the much reduced river flow. For this reason Alternative B has been developed, with essentially the same pro- ject arrangement except that approximately 19 percent of the average annual flow into Chakachamna Lake would be released into the Chakachatna River below the lake outlet to maintain the fishery resource. Because of the smaller flow available for power production, the installed capacity of the project would be reduced to 330 MW and the firm energy delivered to Anchorage would be 1374 GWh per year. The estimated cost of energy is 43.5 mills per KWh. The cost estimate included an allowance for facilities for downstream flow release and for passage of fish at the lake outlet. Layouts of these facilities were not prepared. Obviously, the long term environmental impacts of the project in this Alternative B are significantly reduced in comparison to Alternative A. 2-12 2.5.3 Chakachatna Tunnel Alternatives C and D An alternative to the development of this hydro- electric resource by diversion of flows from Chakachamna Lake to the McArthur River is by construc- ting a tunnel through the right wall of the Chakachatna Valley and locating the powerhouse near the downstream end of the valley. The general layout of the project would be similar to that of Alterna- tives A and B for a slightly longer power tunnel. The geologic conditions for the various project features including intake, power tunnel, and power- house appear to be favorable and very similar to those of Alternatives A and B. Similarly no insurmountable engineering problems appear to exist in ~evelopment of the project Alternative C, in which essentially all stored water is diverted from Chakachamna Lake for power production, could deliver 1248 GWh of firm energy per year to Anchorage and provide 300 MW of peaking capability. Cost of energy is estimated to be 52.5 mills per KWh. While the flow in the Chakachatna River below the powerhouse at the end of the canyon will not be substantially affected, the fact that no releases are provided into the river at the lake outlet will cause a substantial impact on the anadromous fish which normally enter the lake and pass through it to the upstream tributaries. Alternative D was therefore proposed in which a release of 30 cfs is maintained at the lake outlet to facilitate fish passage through the canyon section into the lake. In either of Alternatives C or D the environmental impact would be limited to the Chakachatna River as opposed to Alternatives A and B in which both the Chakachatna 2-13 2.5.4 and McArthur Rivers would be affected. Since the instream flow release for Alternative D is less than 1% of the total available flow, the power production of Alternative D can be regarded as being the same as those of Alternative C at this level of study {300 MW peaking capability, 1248 GWh of firm energy delivered to Anchorage) • Cost of power from Alternative D is 54.5 mills per KWh. The cost of energy from Alternative D is 25% greater than that for Alternative B and E and is close to the cost of alternative coal-fired resources. Therefore, it was decided to concentrate further studies on the McArthur River alternatives. Alternative E In the development of Alternative B, no specific method was developed for release of instream flows into the Chakachatna River immediately downstream from the lake outlet, and no specific facilities were developed for the passage of upstream and downstream migrant fish at the lake outlet. Instead a lump sum cost allowance was provided to cover these items for Alternative B. However, in Alternative E which is a refinement of Alternative B, development by tunnel to the McArthur River, specific facilities for providing instream flow releases and fish passage facilities were developed and incorporated into the proposed project structures. To facilitate the arrangement of these facilities, it became evident that a more limited reservoir drawdown was essential. The range of 2-14 reservoir level adopted was maximum level El. 1155 near the historical maximum level, and minimum level El. 1083 to permit gravity discharge of water through the facilities at the lowest operating water level. With this operating range in the reservoir and with an installed capacity of 330 MW, the project can produce 1301 GWh per annum at a 45% load factor. If a 50% load factor were to be retained, the installed capacity of the powerhouse would reduce to approximately 300 MW, which would reduce the overall project cost by about 5-10%. However, at this st-age of the project development, such a refinement was not considered warranted, and the same installed capacity as developed for Alternative B was retained for Alternative E, i.e. 330 MW. Significant project data for Alternative E are set forth in Table 2-1. Alternative E is also based on the power tunnel being driven by a tunnel boring machine which resulted in a significant reduction in cost compared with conven- tional "drill and shoot" methods previously adopted for Alternatives A through D. In addition, the power tunnel profile in Alternative E was modified to a uniform grade from the intake at Lake Chakachamna to the powerhouse in the McArthur valley. The estimated cost of energy is 44.5 mills per kWh. It should be noted that the significant saving in tunnel cost for Alternative E, as compared with Alternative B, is offset by the increased cost of the fish passage facilities and slightly lower energy production, thereby yielding a firm energy cost slightly higher for Alternative E than for Alternative B. 2-15 TABLE 2-1 RECOMMENDED ALTERNATIVE E PROJECT DATA Chakachamna Lake Maximum water level, natural conditions, {ft.) Minimum water level, natural conditions, approx. (ft.) Surface area at elevation 1155 (sq. mi.) Total volume at elevation 1155 (Ac. ft.) Drainage area (sq. mi.) Average annual inflow, 12 years (cfs) 1,155 1,128 27 Correlated average annual inflow, 31 years (cfs) 4,483,000 1,120 3,606 3,781 Reservoir Operation Normal maximum operating water surface elevation (ft.) Normal m1n1mum water surface elevation (ft.) Active storage (Ac. ft.) 1,155 1,083 1,105,000 Dike Type Le ng t h , { f t • ) Crest elevation (ft.) Maximum height (ft.) Volume (Cu. yd.) Spillway Type Crest elevation (ft.) Discharge capacity (cfs) Power Tunnel Type Diameter, internal (ft.) Hydraulic capacity (cfs) Surge chamber (Dia. x Ht. Ft.) 2-16 Overflow rockfill 600 1,177 49 250,000 Free overflow 1,155 55,000 Circular, concrete lined 24 7,200 48 X 450 TABLE 2-1 (cont'd) Penstock Number/Type Diameter, internal (ft.) Concrete lined Steel lined Powerhouse Type Cavern size (L x W x H Ft.) Turbines Generators Unit output (MW) Maximum net head (ft.) Minimum net head (ft.) Maximum discharge (cfs) Distributor centerline elevation (ft.) Installed capacity (MW) Average annual firm energy (GWh) Average annual secondary energy (GWh) Load factor Fish Passage Facilities Maximum release (cfs) Minimum release (cfs) Fish passage tunnel (L x W x H Ft.) Economic Parameters Estimated total cost $ billion Cost of energy (mills per kWh) Cost per installed kW (S) Construction period (Mos.) 2-17 1-Circular, concrete lined 4-Circular, steel lined 24 10 Underground 250 X 65 X 130 4 Vertical Francis Synchronous 82.5 938 866 7,200 190 330 1,301 290 .45 1,094 343 7800 X 18 X 20 1.31 44.5 3,985 76 PROJECT DEVELOPMENT STUDIES 3.0 PROJECT DEVELOPMENT STUDIES 3.1 Regulatory Storage The existing stream flow records show a wide seasonal variation in discharge from Chakachamna Lake with 91 percent of the annual discharge occurring from May 1 through October 31 and 9 percent from November 1 through April 30 when peak electrical demands occur. The storage volume required to regulate the flow h~s been reportea to be in the order of 1.6 million acre- feet {USBR, 1962). The elevation of the river bed at the lake outlet has been reported as 1127-1128 feet (Giles, 1967). This elevation is thought to have varied according to the amounts and sizes of solid materials deposited in the river bed each year by the meltiny toe of the glacier, and the magnitude of the annual peak outflow from the lake that is available to erode the solid materials away and restore the river channel. The above-mentioned volume of regulatory storage can be developed by drawing down the lake by 113 feet to Elevation 1014. The original studies performed in 1981 adopted such a reservoir operating range in developing project alternatives A, B, C and D. However, when the 1982 studies for development of suitable fish passage facilities at the lake outlet were initiated, it became evident that a lake drawdown to El. 1014 was not suited to the provision of such facilities. Therefore a modified range of reservoir operating level was adopted as discussed below. 3-l If the maximum lake level is raised to El. 1155 and 72 feet drawdown is considered, then a regulatory storage of 1,105,000 acre-feet is provided with increase in head. Although previous studies of the project have discredited the possibility of locatiny a control structure at the lake outlet because its left abutment would have lain on the toe of the Barrier Glacier, it is believed that a relatively low dike with 27 feet of hydraulic head plus freeboard could be constructed and maintained at this location. This is discussed further in Section 3.5.1. The Barrier Glacier ice thickness was measured in 1981 by the USGS using radar tech11iques. The data has not yet been published but verbal communication with the USGS staff has indicated that the ice depth is probably 500-600 feet in the lower moraine covered part of the glacier near the lake outlet. Thus it would appear that the outlet channel from the lake may be a small gravel and boulder lined notch in a deep bed of ice. 3.2 Chakachatna Darn The possibility of gaining both storage and head by means of a dam on the Chakachatna River was first posed in 1950 by Arthur Johnson (Johnson, 1950) who identified, though was unable to inspect, a potential darn site about 6 miles downstream from the lake outlet. Three years later, during the 1953 eruption of Mount Spurr, a mud flow descended the volcano slopes and temporarily blocked the river at this location, backing it up for about 4 miles until it overtopped the debris darn. At this location, the river today is 3-2 still backed up almost 2 miles des~ite the occurrence of the August 1971 lake breakout flood estimated to have peaked at about 47n,ooo cubic feet per second (Lamke, 1972). This flow is about twenty times larger than the maximum daily discharge that occurred during the 1959-1972 period of record. Examination of aerial photographs taken after the 1953 eruption between 1954 and 1981 indicate that subse- quent mud flows, though of smaller magnitude, may have occurred but probably did not reach the river. The source of this activity has been Crater Peak, an active volcanic crater on the southerly flank of Mount Spurr. It lies directly above and in close proximity to the postulated darn site and thus poses serious questions on the safety of this site for construction of any form of dam. At this location, generally from about 6 miles to 7 miles downstream from the lake outlet, the river is confined within a canyon. Both upstream and downstream, the valley substantially widens and does not appear to offer any to~ographicaly feasible sites for locating a dam. Within the canyon itself, conditions are rather unfavoraule for siting a dam. Bedrock is exposed on the right abutment, making this the most likely site for a spillway, but the rock surface dips at about 40-degrees toward the river channel. At this location, the peak discharge of the probable maximum flood calculated according to conventional procedures would be in the order of 100,000 cubic feet per second. The crest length of a spillway would have to be in the order of 200 feet and siting it on the steeply dipping 3-3 3.3 3.3.1 right abutment rock surface would be difficult and costly. surf ace examination of the 1 eft abutment condi tior1s, as discussed in section 5.2.3.2 of this report, indicates that they consist of deep unconsolidated volcanic materials. These would require a deep diaphragm wall or slurry trench cutoff to bedrock, or an extensive upstream foundation blanket to control seepage through the pervious raaterials lying or! this abutment. Very high costs would also be attached to their construction. The presence of the volcano and its potential for future eruptions accompanied by mud flows as well as pyroclastic ash flows is prouably the overriuing factor in discrediting the feasibility of constructing a dam in this canyon location. Consequently, this concept has been temporarily set aside from further consideration at the present stage of the studies, and the main thrust has been directed toward development by gaining regulatory storage by drawin<.::~ down the lake water level and diverting water from a submerged intake in Chakachamna Lake through a tunnel to the McArthur river, or through a tunnel to the mouth of the Chakachatna Valley, as discussed in the next two sections of this report. McArthur Tunnel Devlopment Alternative A Initial studies have been directed toward development by means of a tunnel to the McArthur River that would 3-4 maximize electrical generation without regard to release of water into the Chakachatna River for support of its fishery. Two arrangements have been studied, the first being a tunnel following an alignment about 12 miles long designated Alternative A-1 and shown in Figure 3-1. This alignment provides access for construction via an adit in the Chakachatna Valley about 3 miles downstream from the lake outlet. As discusssed in section 9.0 of this report, the tunnel would be 25 feet internal diameter and concrete lined throughout its full length. The second tunnel studied is designated Alternative A-2 and follows a direct alignment to the McArthur Valley without an intermediate access adit as shown on Figure 3-2. As further discussed in Section 9.0 of this report, this tunnel would also be 25 feet diameter and concrete lined. Although the tunnel for Alternative A-1 is about 1 mile longer than that for Alternative A-2, it would enable tunnel construction to proceed simultaneously in four headings thus reducing its time for construction below that required for the shorter tunnel in Alternative A-2. Nevertheless, the studies show that the economics favor the shorter tunnel and no other significant factors that would detract from it have been identified at this stage of the studies. There- fore the direct tunnel route was adopted and all further references in the report to Alternative A are for the project layout with the direct tunnel shown on Figure 3-2. 3-5 Typical sketches have been developed for the arrange- ment of structures at the power intake in Chakachamna Lake and these are shown on Figure 3-4 witlt typical sections and details on Figure 3-5, Similarly, lay- outs have been developed for structures located beyond the downstream end of the tunnel. These include a surge shaft, penstock, manifold, valve gallery, power- house, transformer gallery, access tunnel, tailrace tunnel and other associated structures as shown on Figure 3-6. For Alter11ative A, the installed capacity of the power- house derived from the power studies discussed in Section 4.0 of this report is 400 MW. For purposes of estimating costs, the installation has been taken as four 100 MW capacity vertical shaft Francis turbine driven units. It is to be noted that the layout sketcl1es mentioned above and those prepared for other alternatives con- sidered in this report must be regarded as strictly typical. They form the basis for the cost estimates discussed in Section 8.0 but will be subject to re- finement and optimization as the studies proceed. For example, the lake tapping for the power intake is laid out on the basis of a single opening about 26-feet in diameter. This is a very large underwater penetration to be made under some 150-170 feet of submergence, and the combination of diameter and depth is believed to be unprecedented. In the final analysis, it may prove advisable to design for multiple smaller diameter openings. The information needed to evaluate this is not available at the present time. 3-6 P LA N ~ 5LO"t<. ~ ru:.;,Yc;_ I !I"L . ~-t-I -I ---t """' 4000 fl(T -p R 10 F l +-L E 1000 1000 2000 FEET V ERT I CAL SCAI._E 200 +00 300+ 00 400+00 500 00 ~29Q0f -~+--k- 1 1000 0 Z.f ' 0/A. COAIC . L IA:tl!. 0 PEl./ STOC I< 600+ 00 r I /All/. EL . /79.5 I I i-~~- 00 NOTES: 1.) T"OPOGI?APHY I S FROM US G 5 Q t/AORAAJGLe MA PS. Z.) COI..J T"O UR I AJT"ERVAL I S 10 0 FEET". '-) VeRrtCAI._ OATU""" I S MEAN SEA LEVEL . 4.) HORIZONTAL GR/015 UNIVEI'f:SAL TRANSVERSE MERCATOR PROJECTION, 1927 NORTH AMEII/CAN DATUM . 5.) SEE FI6URE5 3 ~4 AND 3 ~5 FORVATE SHAFT OETAII..:S ANO F16t/R£ 3·11 FOR St/R6£ TANK, PENSTOCK ANO POWER· HOtiSE GENERAl.. Al'fi'IANGEMENT. 5000 5ECT/OiJ 4000 (T Y P I CAL) AL7-A-Z 3000 2000 2000 0 2000 R O R I ZOI./TAL SCALE ...... ;;;,j . 1000 0 1000 Ve RTICA L S CAL E "' J . 100+ 00 2 00+00 300 +00 P LA AJ SECTION (7YPtc""' L) AL7-B 4000 FEET I 2000 FUT P R 0 F I L E I 400+00 500+00 600+00 5000 SURGE Q Sf>IAFI 4000 1:1 -.. ~ Ill ~ II) M OTES : 1.) T OPOGRA P H Y 15 !"'ROM USC.S QUAOR;f AJC.LE M APS 2.) COI./TOUR INTeR VAL 15 100 FEET ,,) VERTI CAL OA IUM IS MEAN SEA ££VEL . 4) HORIZONTAL GRID IS UNIVERSAl TR,4N~rVERS;fl MERCATOR PROJ ECTION, 1927 NORTH AMERICAN OAT/1M. 5)SEE FltJ//RES !!-4 ANO !J-5 FOJ'?GATE SHAFT PETAILS ANO F16URE !!·ID FOR 5 //lltJE TANK , PENSTOCK AND POWERHOUSE IJENEIIAL ARRANGEMENT. NOTeS : p L A AI !.) 7"0POGRAPHY I:S 1'"~0.41 U56S QUAORAAJGL E MAP S , 2000 2000 4000 FElT t .) COA..I7"0UR /AJTERVAL IS 100 ,<'EET ,.) VE~ii CAL OA7"UM t :S McAA..I :SEA LEVel.. of',) HOR /ZOAJiAI.. &RIO I S UA../IVERSAL TRANSVeRSE. A1ERCATOR PROJEC i/OA..I, 192.7 A/ORTH AMERICAAI lMT"UM. ~)!SEE F I&URES ~-4-AAIO 3·7 FOR GA7"E :SHAFT O E.7"A /L S AA/0 FIGURe ,_c;. FOR SURGE TAAJK., P E A/STOCK. 5000 ANO POWERHOUS£ GENERAL AI?RANGEMENT. 4000 4 000 3ooo I 2000 Ef 1000 ~ 5''Ho~SIOSHOE Ti.INA/EL. /NV. E:L. 9M.O 0 p R 0 F I L E HOR I ZO AI TAL SCALE VAlVES V ERTI CAL SCALE 5ECT/ON (T YP I CAL) IOOtOO 200 +OO 300 +00 400+ 00 500 + 00 600+ 00 MAx . POOL El.... /15 5 . 0 APPRO)(. PReSENT CHANNeL. INVe F:T AT L.AK£' OUTLET EL.. /128.0 sz M IN. w. S . cL. /08.3 . 0 ?eV'~ '~ "'s.· o . 9/2 .0 5ECTIO!V AL St~L -....... ' EL . L. TRAAIS!T IO AI_ L ELEVAT!O!li I' I I I I' I . . i GATE MAtAIICI..IA.AIC£ s ;.,AFT WHEEl cO L..:ER6ENC Y 6ATC. ·I TRA A1 5 1TION No . DA TE REVISION ALASKA POWER AUTHORITY ANCHORAGE, ALASKA CHAKACHAMNA HYDROELECTRIC PROJECT GATE SHAFT SECTION SHEET-I BECHTEL CIVIL & MINERALS, INC. AEY . FIGURE 3-4 TUAIIJEL ct.. VARIIOS 71\""-/' '\ I" J :28 0 5 EC T I ON @) % I 0 ct.. 'i'06 o 28 0 5ECT!O/I....I @) ~ I 0 T ..JiJ IJ C L AIJD 5 rl A' T t:t.. "'iZ o TRAI.ISITIOAI 5 ECTION % I o 13ATTERY RACK TU.VIJE 1.-AiJO SHAFT 27 0 I 5ECT/OAJ 5ECT!OM 1> 10 ~ 10 5ECT!OIV ~ I 0 18 0 18 0 TRAIJS/TIOAI 5£CT/OIJ @) {j I 0 CHARGeR -GATE HOIST ROO STORAGE N DATE REVISION AlASKA POWER AUTHORITY ANCHORAGE, ALASKA CHAKACHAMNA HYDROELECTRIC PROJECT GATE SHAFT SECTIONS SHEET-2 BECHTEL CIVIL & MINERALS, INC SAN FRANCISCO DESIGNED ENIJR S\JPV ll REV FIGURE 3-5 In similar vein, the penstock is shown as a single inclined pressure shaft descending to a four-branched manifold at the powerhouse level with provisions for emergency closure at the upstream end. Again, this is a very large pressure shaft, but the combination of pressure and diameter is not ut~recedented in sound rock. Other considerations, such as unfavorable hydraulic transients in the manifold, or oyerational flexibility, may support the desirability of construc- ting a bifurcation at the downstream end of the tunnel with two penstocks, each equipped with an upper level shutoff gate, provided to convey water to each pair of turbines in the four-unit powerhouse. such an arrangement would cost more than the single penstock shaft. Turbine shutoff valves are shown located in a valve chamber separated from the powerhouse itself. Optimi- zation studies should be made i11 the future to evalu- ate whether these valves can be located inside the powerhouse at the turbine inlets, or wl1ether a ring gate type installation inside the turbine spiral cases might be preferable. The powerhouse is shown a~ an underground installation. This appears to be the most logical solution for development via the McArthur River because of the steep avalanche and rock slide-prone slopes of the canyon wall. For the same reason, the transformers are shown in a chamber adjacent to the powerhouse cavern. A surge chamber is shown near the upstream end of the tailrace tunnel. It may prove more advantageous for this relatively short tailrace tunnel 3-17 3. 3. 2 to make it freeflowing in which case the tailrace surge chamber would not be reyuireJ. The object of the qbove comments is to point out some of the options that are available. The arrangement of structures shown provides for a workable installation. Because of the limited engineering studies performed to date, it is not to be regarded as the optimum or most economical. Optimi~ation will be performed at a later date. The layout is a workable arrangement that gives a realistic basis on which to estimate the cost of constructing the project, and a separately identi- fied contingency allowance is provided in the estimate to allow for costs higher than those foreseen at the present level of study. Alternative B This alternative considers what effect a teBtative allocation of water to meet instream flow require- ments in the Chakachatna River would have on the amouht of energy that could be generated by Alterna- tive A which would use all stored water fot energy generation. The tentative instream flow schedule is discussed in section 7.3.2 of this report. For diver- sion to the McArthur River, and reservation of water for instream flow releases, the tunnel diameter would be about 23 feet. Based on the power studies dis- cussed in section 4.0, the installed capacity of the powerhouse would be reduced to 330 MW. The tunnel alignment and basic layout of structures generally is the same as that shown for Alternative A in Figure 3-2. The diameters of hydraulic conduits and the dimensions of the 330 MW powerhouse would be smaller than for the 3-18 3.4 3.4.1 400 MW powerhouse in Alternative A and appropriate allowances for these are made in the cost estimates. When the various alternative arrangements of the project were developed in the 1981 study, no specific plan had been developed for the provision of releases of flow into the Chakachatna River immediately down- stream from the lake outlet nor for the provision of fish passage facilities at the lake outlet for upstream and downstream migrants. It was recognized that suitable structures would be difficult to develop and would be very expensive. It was also planned that, due to the presence of the glacier at the lake outlet, the fish passage facility would have to be constructed inside a tunnel within the massive rock mountainside forming the right side of the lake outlet. Since no plan for such facility had been developed at that stage of the studies, a provisional allowance of $50 million was shown in the estimate for fish passage facilities. During the second phase of the study in 1982, the concept of fish facilities and operation of the lake has been further developed for this alternative and it is described at the end of this section as Alternative E, the recommended alternative. Chakachatna Tunnel Development Alternative C The initial studies of this alternative focused on development of the power potential by means of a tunnel roughly paralleling the Chakachatna River 3-19 without release of water for instream flow require- ments between the lake outlet and the powerhouse where the water diverted for power generation would be returned to the river. The tunne~ alignment is shown on Figure 3-3. This alignment offers two convenient locations for intermediate access adits during construction. The first is about 3 miles downstream from the lake outlet in the same location as discussed in section 3.3.1 above for Alternative A. The second adit location is about 7 miles downstream from the lake outlet. The total tunnel length in this arrangement is about 12 miles and the adits would make it possible for construction of the tunnel to proceed simultaneously in six di erent headings. The arrangement of the power intake is essentially the same aud in the same location as for Alternative A as shown on Figures 3-4 and 3-5. The tunnel is also 2:i feet internal diameter, concrete lined, and penetrates the mountains in the right wall of the Chakachatna Valley. The arrangement for the surge shaft, pen- stock, valve gallery, powerhouse and asssociated struc- tures is similar to that for development via diversion to the McArthur River but is modified to fit the topo- graphy and lower head. The layout is shown on Figure 3-7. The head that can be developed in Alternative c is roughly 200 feet less than in Alternatives A and B and the installed capacity in the powerhouse is only 300 MW as determined from the power studies discussed in Section 4.0 of this report. 3-20 COIJCflE. TE LIIJE.D COIJCRE.TE -p L A )J SECT/O;U 5ECTIOIJ ® ACCESS TUAIIJG.L \)~ -~ lEt... 1126 0 ~" ~~~~ <:i"'- \l~ \I'll .... \l~ :::;:'1: ''<: \'l~ ' --~ 5ECTIO/J @ SHAFT I I 1/LT S ----~ peiJSTOC/<. I I .SECTION ~ UIJITS Ei_ 190 0 ~ ' 5ECT!01JAL ELEVATIO!V BECHTEL CIVIL & MINERALS, RNC 80 80 160 FEET REV FIGURE 3-6 3.4.2 For purposes of estimating the present costs of con- struction, the powerhouse is taken as being located underground. If this Alternative were to be pursued, future studies would be made to determine if economy can be attained by locating it outside on the ground surface. Comments made in Section 3.3.1 regarding the layout sketches for the McArthur powerhouse in Alternative A apply equally to the powerhouse and associated structures for the Chakachatna Powerhouse considered in Alternative C. Alternative D studies of this alternative take account of tt1e effect on electrical generation of reserving water to meet instream flow requirements in the Chakachatna River. The tentative water release schedule is less than that condidered for development by power diversions to the McArthur River as discussed in Section 7.1.5 of this report. The reason for this is that in the lower reaches of the river, downstream from the proposed powerhouse location, the river flow will include those waters that were diverted for electrical generation. These lower reaches of the river are probably more important to the fishery than the reach of the river between the lake outlet and the proposed powerhouse location. This probability is suggested, though not fully confirmed, by observations made of fish runs during the 1981 and 1982 field studies. These have indicated that the Chakachatna River, between the lake outlet and the proposed location of the powerhouse, serves primarily as a travel corridor for fish passing through the lake to spawning areas furth~r upstream. The river itself, in this reach does not a~pear to offer much in the way of suitable spawning and juvenile rearing habitat. on the other hand, 3-25 3.5 3.5.1 significant numbers of fish and spawning areas were observed in the lower reaches of the river downstream from the proposed powerhouse locations. Consequently, the tentative instream flow releases are ~mall when compared with those considered for development via power diversions to the McArthur River, as discussed in section 7.1.5 of this report. The tunnel diameter for development of the power potential via the Chakachatna Tunnel with provision for instream flow releases, is 25 feet, the same as that mentioned in section 3.4.1 without such releases. The installed capacity in the powerhouse also rehlains the same at 300 MW. The layout sketches shown in Figures 3-3 and 3-7 for Alternative C are equally applicable to Alternative D as are the comments set forth in Sections 3.3.1 and 3.3.2 regarding the layout sketches for de-velopment via the McArthur River. McArthur Development -Recommenued Alternative E General This alternative is basically similar to Alternative B, but modified to include water release facilities into Chakachatna Riverb fish passage facilities at the lake outlet and modification of lake operating levels to accommodate these facilities. The power tunnel would have a 24-foot internal diameter circular section and the diameters of other hydraulic conduits, the powerhouse arrangement, sizing and location will be the same as described for Alternative B except as shown in Figures 3-2 and 3-6. It is to be noted that the emergency closure gate located at the head of the penstock in Alternative B cannot be retained in 3-26 the layout for Alternative E. This results in a loss of a certain amount of operating flexibility to the extent that the penstock, upstream of the valve chamber, cannot be dewatered for inspection without dewatering the power tunnel. Likewise, in the event of a failure in the valves or the conduits upstream of the valves, the whole station would have to be shut down and the tunnel dewatered, before the rupture could be repaired. The operating range of the lake will be modified. The maximum level will be taken as the historical maximum evidenced by a white mark on the rock slopes of the lake shoreline at approximately El. 1155. A wide rockfill dike will be constructed at the lake outlet from the spoil material available from the spillway excavation described below to raise the lake outlet by approximately 27 feet. The reservoir level control will be established by an unlined spillway channel at El. 1155 excavated into the rock on the right side of the outlet. The layout is shown in Figure 3.8. The lake level operating range will be 72 feet down to El. 1083 rather than the 113 feet that was previously available in the studies for Alternatives A through D. The power tunnel intake level is maintained at the level previously used to provide even greater submergence to reduce potential problems of attracting downstream migrant fish into the power tunnel. Most flood waters will be released via the unlined spillway channel cut through the granite in the right abutment. This unlined channel has a capacity of 55,000 cfs, and will therefore handle all flood releases up to 55,000 cfs. Flows greater than this up to the presently estimated probable maximum flood of 3-27 3.5.2 100,000 cfs will pass both through the spillway and over the rockfill dike. It should be noted that the maximum peak discharge in the period of record of 1959- 1971 was 23,400 cfs if the "dam-break" type of flood which occurred in August 1971 is disregarded. Future studies of the required spillway size may indicate that a reduction in size below the 55,000 cfs capacity may be possible. It is considered that since overt0ppin~ of the rock dike will be a very infrequent occurrence, repair of the dike after sucl1 an event would ~e an acceptable maintenance procedure. such repair can be scheduled in the spring ~efore the lake rises to the level of the dike in July or August. Periodic maintenance will also probably be re~uired to r~pair damage to the dike caused by movement of the ice in the toe of the glacier. Water Releases and Fish Passage Facilities To provide instream releases into the Chakachatna River and arrange for ~oth upstream and downstream migration of fish between the river and the Chakachamna Lake, a concept for a con~eyance system was developed which consisted basically ~f fish ladd~rs at the upstream and downstream ends of two interc0nnectiny channels located in a tunnel. The system is a gravity flow system and does not rely on any pumping for its operation. The layout is shown in Fig. 3-8. The facilities will be located in the right bank granitic rock abutment to provide a secure structure protected against avalanches and rockfalls and to minimize the lenyth of the tunnel. A oeep 3-28 0 5ECT!OAJ CO.UCI1ETE SUR.GE 5HAI'T --- EL 1/2.0 0 ' 7 ------,,.........,..------Y / / / / / / COAJCRETc TAILRACE / / / / / / / / / / / / / / / / / / PLUG~/ / / / I CHAMBER / / / / / / / / ' p L A BO 80 160 FEET ~~~~iml <I. JAJITS EL ~Cl'7 0""'-, I 5ECT!O)JAL 0 . ELEVATIO)J 8fJ 160 FEET 0 t ACCESS TUAJIJEL 5ECT!OIJ SECT! O)J I 5ECT:!OAJ N DATE REVISION DESIGNED CHECKED _J...j ENOR SUPV .fJ API'D/ • DRAWINGN REV FIGURE 3-7 I I ( N2~n,tUJO + INLGT SITE PLAN t"., zoo' + / ( f' -------- CHAI(At:HAMAIA tAl!£ OUTLET SITE PLAN G'ACIU ...,. I I '*' DATE GRAPHIC SCALI FliT 1"""' GRAPH&c SCALE fUT 1 .... REVISION ALASKA POWER AUTHORITY AMCHOIIAGI!. ALASKA CI!IAKACI!iAMMA HYDI!UDlEI.lECTIR~C PROJECT CHAKACHAMNA LAKE OUTLET GENERAL ARRANGEMENT BIECKmL CML & M!fi\IIERAI.S, !NC SAN FRANCISCO CHECKED DRAWING,., REV FIGURE 3-8 11~5" KAX WL. .,.. I/26MtN IV<. 112SNAX. WL ---<> /116 Mil( WL ~ INLST CCWTROL 6AT:e TYP,cAt. Ar t<ACN WATt'.~! SUPPLY CNAM8EI! WATER. S"t/PPLY CNAMBE-" (~ PLAN EL 1154 -EL 1/!2 /1.-/o1 ~ ~5 DIRe&riON OF WArER FLOW FI~S ~ND'rE WAreA! .:JVA1:PAC6 EL.HVArJ0/'11 IN Fe£T ,_,St.. • • 0 PLAN Et. 1184-EL 1115 /1" ID 1 ACCGSS rLINN€L S€CTION (TYI"tc.41.. DoWNST'REAM FRDM INrLS,Il<UICrlt:W W/rN INS'T11i!5A.If FI.DW ~LeA~c ,PUHfE') !1• /01 1/0S,ffAX lVI -/QJI6 Nil>' II'£ I0!16.VAX WL /OIM! MIN WL. Ill» ~ .. PLAN EL 1114-EL 1095 f'AID' PLAN EL 1085 /11a/t::~1 ,. ,. GRAPHJC BeAU nn , ... CHAKAC~AMii!A ~YDROELECTRIC PROJECJ UPSTREAM FISH PASSAGE FACILITIES PLANS AND SECTION BECHTEL CIV!l & MINERAlS, DNC SAN FRANCISCO DESIGNED DRAWN CHECKED APP'D DRAWJNON REV FIGURE 3-9 3.5.3 approach channel will be excavated in the alluvial deposits on the right side of the lake outlet to convey water from the lake to the fish release facilities located in an excavated cavern in the right abutment near the lake outlet. O~stream Migrants Facility The facility for upstream passage of adult migrant fish would consist of a conventional fish ladder with overflow weirs having 1 foot difference in elevation between each pool. Alongside each tier of ladder pools is a water supply chamber that serves a 10 foot interval in the range of lake level. Each pool in a given tier would have a gated connection to the water supply chamber, so that for a given lake level, the gate leading to the pool whose water level is 1 foot lower than the reservoir would be open, thus letting water run from the supply chamber into the ladder. All other gates between the supply chambers and pools would ue closed. As the lake level changes, the gates would be manipulated accordingly. At this stage it is assumed that these gates would be operated manually although it would be possible to automate their operation, with the selection of "open" gate tied to lake level. A control gate is also shown between each water supply chamber and the lake. Fish ascending the ladder would rise through the pools until they reached the one receiving water from its supply chamber. The fish would then pass into the supply chamber and exit into the lake through the control gate opening. This upstream migrant structure would be constructed in an underground chamber excavated in the rock mountainside 3-31 3.5.4 adjacent to the existing natural lake outlet. The concept is shown in Figures 3-9 and 3-10. Downstream Migrants Facility The facility for downstream passage of out-migrants and for provision of minimum downstream flow releases is shown in Figure 3-11. The concept cor1sists of three, 15 feet wide fixed wheel type gates stacked one above the other. The proposed mode of o~eration is that when the water level is between El. 1155 and El. 1127, the top gate would be lowered the amount necessary to discharge the desired amount of water that would plunge into a stilling basin and return to the river through the discharge tunnel. The middle and bottom gates would be closed. Whe11 the lake level falls to El. 1127, the top gate would be raised above the water surface and the middle gate would be lowered to discharge the desired amount of water. As the water level descends below El. 1001, the middle gate would be raised and the lowest gate would take over the control of discharge. This gate will be progressively lowered below the invert of the outlet channel as the lake level falls. Manipulation of the gates would be in the reverse sequence during the condition with a rising lake water level. The depth of flow in the stilling basin immediately downstream from the gates is relatively shallow in order to prevent entrainment of air at depths and pressures which could result in nitrogen saturation harmful to the fish. 3-32 RtXI< MO<JNr/III'ISID!!. .4V StoPe ~PP,i?OJ( .fO ClfiiKACII.tJMNA LAKE SECTION SECTION •• •• ORAPH1C 8CAU niT , ... .. CHAKACHAMNA HYDROELECTRIC PROJECT uPSTREAM FISH PASSAGE FACILITIES SECTIONS BECHTEL CIVIL & MINERALS, INC SAN FRANCISCO OESIONm DRAWN CHECI<ED DRAJI'INONa FIGURE 3-10 MIN A=c El. 10 8.3 - et. to76J ~~~ :-:11-:-\~:;-:v---, ~;;v:""":':-:v.>~~ f E:L /074). --T-- 111 e ill 1/t;;O SECTION 1'1-Jo' I -\11~ I ..:::: uf I\ =-- SECTIONAL PLAN 111 -= to' /( (I! (1 lfl \II =-/1 10 10 20 GRAPHIC SCALE FEET 1 10' No DATE REVISION AlASKA POWIER AUTHOR~TY ANCHORAGE, ALASKA CHAKACHAMNA HYDROELEClRIC PROJECT DOWNSTREAM FISH PASSAGE FACILITIES INSTREAM RELEASE STRUCTURE BECHTEL CIVil & MINERALS, INC CHECKED AP!'O DRAWING N REV FIGURE 3-11 3.5.5 3.5.6 Conveyance Channel Both upstream and downstream migrants will travel in separate channels located in a common tunnel. The upstream migrants would utilize a 6' x 4' channel dimensioned for the fish ladder discharge of 40 cfs. The out-migrants would use the main channel 18' x 7' dimensioned for maximum required monthly release minus the flow in the small channel. (This maximum downstream release as presented in section 4 has been set tentatively at 109~ cfs.) The small channel would be located at one side of the tunnel above the main channel with a road access provided on the other side. A typical section of the tunnel is shown in Fig. 3-9. Both channels would be free flowiny with freeboard provided. Only the main channel which has a maximum velocity of 8 feet/sec., would be fully lined to reduce head loss. In order to keep velocity in the small channel for the upstream migrants at 2 feet/sec., the floor of the channel would have a slightly less gradient than the large channel and 5 drops of 1 foot each will be provided at regular intervals down the tunnel. Outlet Structure A ladder is required at the downstream end of the tunnel to provide a means for the upstream migrants to reach the upper transportation channel inside the tunnel. This ladder will be partially submerged at high releases since the river level rises by an estimated 4 feet when the discharge from the facility is increased from the minimum flow of 343 cfs to the maximum of 1094 cfs. Another 6 ft vertical rise in 3-3~ the ladder is provided to accommodate the difference between the water surfaces in the two channels in the tunnel so that a total of 10 ladder pools would be provided. A horizontal submerged screen would allow the out-migrants to reach the main discharge channel while its presence and a velocity of around l/2 ft/sec through the bars would prevent the large fish fro@ entering the main tunnel discharge channel. The attraction flow coming down the ladder would be 40 cfs. The layout is shown in Figure 3-12. A floating ice barrier installed in the approach channel just upstream of the fish passage facility will prevent most of the ice from passing into and through the facility during the breakup period. However, as a precaution, since it will be very difficult to ensure the complete elimination of the entrance of ice into the facility, it is planned to remove a stoplog barrier which normally diverts the flow through the horizontal screen, thus allowing the flow and ice to continue straight into the side outlet channel and the Chakachatna River, and thereby by- passing the horizontal screen throuyh which the flo¥/ normally passes. This should be an acceptable procedure because the upstream migrants do not travel upstream until after breakup occurs. A small rockfill dike will be constructed across the river channel just upstream of the downstream entrance to the outlet facility so that the upstream migrants will be prevented from entering the section of the river between the fish facility and the lake outlet. Any small inflow into the river between the lake 3-40 VCf.I/Cl.~ ACC£SS TUIJIJEI.. L 71 ---- -------- SECTIOIJAL PLAU /1D-/01 ------ MAXIMVM _ jw_s ~;;~ 1069 _ _ "!!_AI 11'6 E1../0IP5 SE.CTIOIJ 8 I•Jo' SE.CT/OIJ t"• Jo 1 P'I..OW - 10 10 20 GRAPHIC ICALE FElT 1 10' No DATE REVIStON ALASKA POWER AUTHORITY ANCHORAGE, ALASKA CHAKACHAMillA HYDROElECTRiC PROJECT OUTLET FISH PASSAGE FACILITIES PLAN AND SECTIONS BECHTEL CiVIL & MINERAlS, HNC SAN FRANCISCO DESIGNED DRAWN CHECKED APP'D DRAWING N REV FIGURE 3-12 outlet and the f~sh fac~l~t~es outlet w~ll f~lter through the rock d~ke 3 6 TransmLss~on L~ne and Submar~ne Cable At the present stage of the proJect development stud~es, no spec~f~c evaluat~on has been made of transm~ss~on l~ne rout~ng Whether development should proceed v~a the proposed McArthur or Chakachatna Power- house locat1ons, 1t ~s assumed for the purposes of the costs est1mates that the transm~ss1on l~nes would run from a sw~tchjard ~n the v~c~n~ty of e1ther powerhouse s1te to a locat~on ~n the v~c~n~ty of the ex~st~ng Chugach Electr1c Assoc~at~on's Beluga Powerplant The yeneral rout~ng of the proposed l~nes ~s shown on F1gure 3-13 At Beluga, an ~nterconnect~on could be made through an appropr~ate sw1tch~ng fac~l~ty w~th tne ex~st1ng Beluga transm~ss1on l1nes ~f a mutually acceptable arrangement could be negot~ated w~th the owners of those l1nes Thls would enhance rel1ab~l1ty of the total system, but for purposes of th~s report no such ~nterconnect~on has oeen absumed Bejond Beluga, 1t 1s assumed for purposes of the est~mate, that the new transm~ss~on l~nes for the Chakachatna or McArthur Powerhouses would parallel the ex1st~ng trans- m~ss~on corr~dor to a term~nal on the westerly s~de of Kn~k Arm and cross that waterway by submar~ne cables to a term~nal on the Anchorage s~de Beyond that po~nt, no costs are ~ncluded ~n the est~mdtes for any further requ~red power transm~ss~on ~nbtallat~ons In the proJect alternat~ves thus far cons~dered, the cost est~mates are based on power transm~ss~on v~a a pa~r of 230 KV s~ngle c~rcu~t l~nes w~th capac~ty 3-43 3 7 match1.ng the peak1.ng capab1.l1.ty of the respect1.ve power plants Optl.ml.zatl.on stud1.es to determ1.ne whether transml.SSl.On should be effected 1.n that manner or by a s1.ngle l1.ne of double c1.rcu1.t towers should be performed 1.n the future References G1.les, Gordon C , Apr1.l l9b7 Barr1.er Glac1.er Invest1.gat1.ons and Observat1.ons 1.n Connect1.on Wl.th Water Power stud1.es USGS rough draft report Jackson, Bruce L , March 1961 Potent1.al Water Power of Lake Chakachamna, Alaska USGS open f1.le report Johnson, Arthur, January 1950 Report on Reconna1.~sance of Lake Chakachamna, Alaska USGS Lamke, Robert, March 1972 Floods of the Summer of 1971 1.n south-Central, AlasJ..a USGS open f1.le report Un1.ted States Bureau of Reclamat1.on, 1952 Reconna1.ssance Report on the potent1.al Development of water Resources 1.n the Terr1.tory of Alaska ' Un1.ted States Bureau of Reclamat1.on, 1962 Chakachamna ProJect, Alaska Status Report 3-44 \ I ' 1 ~ L ; I I \ I \ I I' I I h 4 0 4 8 MILES SCALE : i'· 4 MILES tVOT£ 5' 1.) TOPOGRAPHY I S FROM USGS QUAORAIJGI..E MAPS 2.)HORIZONTAL GR/0 IS UNIVERSAL · TR-'!MSVERSE MERCATOR PRO..JI!£C TIOAI, /927 AIORTH ANIE RICAiJ DATUM . 3.)VERTICAL OATUM 1$ MEAN LOWER LOW WATER . (~ I I I ¥ '~ I 1 I I t \ ~~ r J lt ~r I ) \: r I I "'"" \ I t I \ ' Un1ted states Department of the Army, Corps of Eng1neers, 1950 / Survey report on Harbors and R1vers 1n Alaska Inter1m Report No 2, Cook Inlet and Tr1butar1es 3-47 I HYDROLOGICAL AND POWER STUDIES I I _) I ~ I i I ) ~ ~~ ~ I t I I 1 t ) I ' ~ I \ I r f \ I I I l~ ' I I I I r: I \ ~ j ~ I : I \ J~ 4 0 4 1 HYDROLOGICAL AND POWER STUDIES Introduct1on Rlver flow records from a gag1ng stat1on are usually accepted as the best 1nd1cator of future runoff from a dra1nage bas1n. The longer the per1od of record 1s, the more rel1able 1t lS assumed to be 1n forecast1ng future runoff For Chakachamna Lake, the records of a gage located near the lake outlet cover only a relat1vely short per1od of t1me, May 1959 to September 1972 Dur1ng that t1me some per1ods occurred dur1ng wh1ch flow rates were not obta1ned, reduc1ng the cont1nuous record to a per1od dat1ng from June 1959 to August 1971 There are no records of 1nflow to Chakachamna Lake, and s1nce that 1nformat1on 1s needed to perform reservo1r operat1on and power stud1es, 1nflows were calculated for the cont1nuous per1od of record by reverse rout1ng of outflows and mak1ng appropr1ate adJustments for changes 1n water levels. Calculated 1nflows for the 11 calendar years 1960 through 1970 were used 1n the power stud1es conducted dur1ng 1981 for Alternates A, B, C and D In order to develop a longer ser1es of 1nflows to Chakachamna Lake, the lake 1nflows were stat1st1cally correlated w1th hydrometeorolog1cal records from other stat1ons Us1ng the resultlng correlat1on, 1nflows were calculated to produce a total per1od of 31 years of recorded and synthes1zed records That 31-year sequence was used to determ1ne the energy-generatlng potent1al for the recommended proJect, Alternat1ve E, dur1ng the stud1es conducted dur1ng f1scal year 1982. 4-1 4.2 H1stor1cal Data Hydrometeorolog1cal data from several stat1ons 1n the Cook Inlet Bas1n were used for the der1vat1on and extens1on of est1mated lake 1nflow records. Streamflow records 1ncluded the follow1ng furn1shed by U. S. Geolog1cal Survey Stat1on No. 15294500 15284000 15284300 15292000 Descr1pt1on Chakachatna R1ver near Tyonek (the lake outlet gag e) Matanuska R1ver near Palmer Skwentna R1ver near Skwentna Sus1tna R1ver at Gold Creek Gag1ng Stat1on No. 15294500 1s located on the r1ght bank of the Chakachatna R1ver close to the outlet of Chakachamna Lake. The gage records 1nclude 13 years and 5 months from May 21, 1959 to September 30, 1972. The gage however, was destroyed by a lake outbreak flood on August 12, 1971 and the records between that date and June 20, 1972 are est1mated rather than recorded flows Thus, the per1od of actual record extends only from May 21, 1959 to August 12, 1971 and from June 20, 1972 to September 30, 1972 Furthermore, dur1ng that per1od, several of the w1nter-month flows were est1mated because of 1c1ng cond1t1ons and 1nstrument fa1lure Inaccurate w1nter records are not a ser1ous eng1neer1ng concern, because only 11% of the average annual flow normally occurs dur1ng the seven months from November through May 4-2 I I ' I I I 1 I I I I I I I I 1 ' ~_J j I I \ -' r 1 I I I ~' -!' I I I I ' I I \ I \ " I II I I~ ' \ ' I I L~ I I ,J In add1t1on to the streamflow data, records of the water surface elevat1on at Stat1on No. 15294500 were also obta1ned from the u. S. Geolog1cal Survey 1n Anchorage Ava1lable meteorolog1cal data cons1st of da1ly temperature and prec1p1tat1on data obta1ned from the U. S. Nat1onal Ocean1c and Atmospher1c Adm1n1strat1on, Nat1onal Cl1mat1c Center, Ashvllle, N.C. for stat1ons at Kena1, Anchorage, and Sparrevohn The locat1ons of these three meteorolog1cal stat1ons are shown on F1gure 4-1. A bar chart show1ng the per1ods of record for these stat1ons 1s plotted on F1gure 4-2 4 3 Der1ved Lake Inflows Chakachamna Lake w1th 1ts surface area of about 26-square m1les stores runoff and prov1des natural regulat1on of flow to the Chakachatna R1ver. In order to der1ve a record of 1nflows to the lake, the regulat1ng effects of the lake were removed from the outflow records us1ng a reverse rout1ng procedure wh1ch uses the bas1c cont1nu1ty equat1on It -ot = As Where It 1s the 1nflow volume dur1ng month t Ot 1s the outflow volume dur1ng month t D. s lS the change 1n lake storage dur1ng month t For all pract1cal cons1derat1ons, the Chakachatna R1ver near Tyonek gage 1s, 1n effect, located at the lake outlet and f1eld observat1ons conf1rmed that gage 4-3 4 4 read1ngs closely represent the lake water-surface elevat1on. Hence, 1t was assumed for the reverse rout1ng computat1ons that the two were the same. E~aporat1on, seepage and other losses of water from the lake were assumed to be small and effect1vely compensated for by d1rect prec1p1tat1on onto the lake surface The lake stage-storage curve used 1n the computat1ons 1s shown on F1gure 4-3. Th1s 1s based on data measured by the USGS and recorded on the USGS maps Chakachatna R1ver and Chakachamna Lake Sheets 1 and 2, dated 1960 Average monthly 1nflows were calculated for the per1od June 1, 1959 through August 31, 1971, and are presented 1n Table 4-l. The calculated 1nflows for the ll calendar years January 1, 1960 through December 31, 1970 were used 1n the power stud1es for Alternates A, B, C and D of the proJect layouts dur1ng 1981. Synthes1s of Long-Term Lake Inflows In order to develop a long-term est1mate of energy-product1on, methods for extend1ng the 1nflow record were 1nvest1gated Transpos1t1on of records from other r1vers 1n the reg1on, correlat1on w1th , meteorolog1cal data from nearby long-term stat1ons, and comb1nat1ons of both, were stud1ed us1ng regress1on analys1s 4-4 r ' II I / r I I \ I > / ...... I -I (1 \ A I I L 1 l I I <..-.) I I { J I I 1\ ~-~ ' ~~ I ( t.J I e oe : ~~ I ie If Q Gill() J. Jl fii~Ctnil UPlOOUIOO l). OIQI 0 !!lOt hiD 11•1 No•f OttiiiiO 6 8 HI Of CP ":10 Do 01 OOD frnl t alto 6 CloHIIOID COt tJ, 4l Ole ociiCIIMI -c.uH v Cl otsiiCD ~~ tftiO hoot.cer OROLOGICAL HYDROMETELOCATIONS FIGURE 4-1 r--' ~, t --\_,~- Chmkachatna River Jun 59 Sept 72 At Lake Outlet i / Matanuska River May 49 Sept 73 At Palmer ] Susitna River Aug 49 Sept 80 At Gold Creek I ' Skwentna River Oct 59 Sept 80 Near Skwentna I Temp. & Precip. Aug 48 Dec 80 At Kenai a Temp. & Precip. Nov 53 Dee 80 At Anchorage Temp. & Precip. July 51 Dec 70 ~ I At Sparrevohn ~ ~~ l:Jdt-,1 l'%j Ht%J 00 H t::l~ ~ tllO t"" 1950 1960 1970 1980 00 l'%j(j') .,.. H I ~g N 0 ~til ~ 1-:1 H 0 2: til ' r I ~ _) ; I __) ;---;. I ) ~-I Cl I I I ' ).. -' I I I ~l j I L1 ~~ 1 I I I [ J 'I I \_J ~~ i I I I '-- ..:I ~ ~ ~ ~ CJ) ~~ ~~ §~ z 0 H E-t ~ ~ ..:I ~ I AREA IN THOUSANDS OF ACRES 28 26 24 22 20 18 16 ).4 12 10 8 6 4 2 I I I I I 1 I I I I I I I I I 126b I I l-... I I I I ~ -~ --I -v---t - I ~ I 1210 r-... I I ............... ~ I / I I I I --I I / I I ~ I I I I I I I 1160 ~ v I I I I ~ I I I I I --I ...- 1 I I l I l I I I I 1110 I I 1 I -I VI \ I I / I I I -I I - I I I 1060 I I ~ ~ I I J I I I --I r I I I I I I 1010 1/ I I I I I Vi I I I I I CAP ~c~ I I I I I I I I I I I I I 960 v 1\ I I / I -j-AREA I I I I I -I I I I I I I ~ I 910 I y ~ l ~ I I I I I I -~I ' I I I I I I I I I 860 810 y I I I """ I I I I I I I I I ~ I I I I I I I I I I I VI I I I ..... ~ I I ~ I I I 1 I i 1 760 [ I I I ---I I 0 1000 2000 3000 4000 5000 6000 I 70001 CAPACITY IN THOUSANDS_OF_ACRE-FEET CHAKACHAMNA j LAKE I AREA & CAPACITY DATA I I ELEV AREA CAPACITY M S L IN ACRES ACRE FEET . 760 0 0 765 810 2,025 770 1,300 7,300 780 2,690 27,200 800 5,670 111,000 0 20 7,320 241,000 40 8,270 397,000 60 9,280 572,000 80 10,400 769,000 900 11 ,590 988,000 20 11 '960 1,224,000 40 12,320 1,467,000 60 12,650 1 ,717,000 80 12,980 1,973,000 1000 13,280 2,236,000 20 13,520 2,504,000 I ( 40 13,740 2,776,000 13,960 3,053,000 60 -I 80 14,170 3,335,000 1100 14,390 3,620,000 20 14,620 3,910,000 40 16,100 4,218,000 42 16,780 4,250,000 60 18,250 4,572,000 80 19,900 4,953,000 1200 22,956 5,382,000 20 24,104 5,852,000 40 26,038 6,354,000 I CHAKACHAMNA LAKE LAKE STAGE-AREA AND CAPACITY FIGURE 4-3 ' c -, l YEAR JAN FEB lo!AR APR 1'1AY 1959 1%0 400o 307 267 393. 3637. .q~1 A77o ')89 470. 346. 1 fl8l. 1%2 633 541. 471o 47[1. 1265. 1°63 498 ~57. 31<;. "'i37 1801. 1°64 "'i64 435. "'i32. 411 1A30 "'" 1ql)'\ '11 q. 219. 337. 398 1286. I 1q66 3A8 :336. .350. 410. lfl93 • 1-' lq67 531 449. .384. 1:'80 2'~30. 1-' !%8 534 510. 467. 630 ~996. 1°69 485 't86 500. 652. 194'1. 1970 497. 504 550. 899. 2265 1971 394. 441. 513. 1275. 4~63. '1EAN 502 431. 413. !:'97. 2241. TABLE 4-1 LAKE CHAKACHAMNA INFLOWS (cfs) JUN JLY AUG SEP 9459. 10381:1. 11731. 36&2. 61137 11~09 9337. 3145 7983. 12808. 10899. 6225. 7925. 13149. 10411. 5542 4735. 13249. 12208. 5847. 8093 10700. 11798 0 4246. 3490. 13C4&o 10';16. 10802. 8072 10"'i03. 9974. 6608. 8761. 14931. 151>95. 6191. 71\08. 13117. 11257. 2793 9271 12510. 7297. 27q3. 678'J 10360 7986. 273'to 12672. 13f>95o 16680. 71138. 12261. 11215. 5049o \ ::...--- OCT 1370. 1439. 1'186. 1197. 2056o 1245 2114. 1953. 2040. 976 3'157. 1359. 1699. ~ov 654. 799. 843. 863. 930. 909. 597. 910. 1215. 689. 1215. 7'12. 864. r~ -' c_ DEC MEAN 5 08. 870. 3220. 6q6. 3767o 6 t:5 0 359C. 710 3587· 662. 3424. 4&6. 36111. 313. 34'\9. 571· 4473a 612. 3532. 541. 3396. 460. 2q29o 585. 3606. Exam1nat1on of the 1nflows to Chakachamna Lake ln Table 4-1, 1nd1cated that, for thls watershed, the hydrologlcal year (water year) should be deflned as the per1od from May to Aprll to m1n1m1ze the overall basln-storage effects. The ma]orlty of the lake lnflow, 93% o± the annual runoff volume, occurs dur1ng May through October, whlle flow recess1on starts 1n November Flows recordea at the lake outlet from November to May were, 1n general, est1mated by USGS personnel us1ng personal JUdgment because lee cover prevented proper funct1on1ng of the stage recorder dur1ng that per1od The accuracy of the recorded w1nter streamflow 1s, therefore, quest1onable, but est1mated total outflow volume dur1ng the low-flow wlnter months lS thought to be reasonable. Because of thelr dlfferent hydrolog1c character1st1cs, 1t was dec1ded that regress1on analyses should be performed separately for the per1ods, May to October, and November to Aprll. In so do1ng, the less-accurate monthly-flow est1rnates for the w1nter per1od would not unduly lnfluence calculat1ons for flows dur1ng the rema1nder of each year The lnltlal selectlon of lndependent varlables to be used 1n the regress1on analyses was based on the lengths of the ava1lable hydrometeorologlc records 1n the reg1on, as well as the potentlal phys1cal relat1onsh1p w1th the 1nflow reg1me of Lake Chakachamna. S1nce Chakachamna Lake ls glaclally-fed, a heat-lnput lndex, such as monthly degree-days above 32°F recorded at Kenal and Anchorage, could be an 1mportant lndependent var1able Monthly streamflow records from nearby watersheds whlch are cons1dered to have hydrolog1c characterlstlcs s1m1lar to that of the 4-12 ) I I ) t \ ~) : 1 J 1.-~ I I I I I I I I I I I ' ~ I i ,._) ' I I '-J ,,.-, I ) LJ c I \ I Chakachamna bas1n were also 1ncorporated 1n the study. These 1nclude the streamflows of Matanuska R1ver at Palmer, Sus1tna R1ver at Gold Creek and Skwentna R1ver near Skwentna In add1t1on, monthly prec1p1tat1on at Kena1 and Anchorage were also cons1dered. The f1nal select1on of the 1ndependent var1ables used for the lake-1nflow synthes1s was based on the results of the prel1m1nary analyses. The f1nal regress1on analyses were performed systemat1cally us1ng d1fferent comb1nat1ons of the pre-selected 1ndependent var1ables 1n a step-w1se regress1on-analys1s program (Bechtel TM 750). The regress1on equat1ons obta1ned were evaluated on the bas1s of probable phys1cal relat1onsh1ps to topograph1c, meteorolog1cal and hydrolog1c cond1t1ons as well as the computed level of stat1st1cal s1gn1f1cance of the correlat1on. It was found that for both the h1gh and low-flow per1ods, May to October and November to Apr1l respect1vely, the monthly streamflow records for the Matanuska R1ver at Palmer correlate well w1th the h1stor1cal monthly Chakachamna lake 1nflows. The regress1on equat1ons obta1ned were May -October. November -Apr1l QLake = 595.0 + 0.8967 QPalmer Q k = 265.3 + 0 4597 Qp 1 La e a mer Correlat1on coeff1c1ents for these two regress1on equat1ons were found to be 0 89 and 0.40 respect1vely and are well w1th1n the 95 percent s1gn1f1cance level. However, the Matanuska gage was d1scont1nued 1n September of 1973. Another set of regress1on equat1ons was therefore requ1red for the flow synthes1s for the per1od after September 1973 New 4-13 correlat~on stud~es were performed. It was found that recorded streamflows for Skwentna R~ver near Skwentna were a good subst~tute for those at the Matanuska gage. The regress~on equat~ons obta~ned were May -October November -Apr~l QLake = 674.67 + 0.5233 QSK QLake = 283 27 + 0.2690 QSK The correlat~on coeff~c~ents for these two regress~on equat~ons were found to be 0 73 and 0.45 respect~vely and are well w~th~n the 95 percent s~gn~f~cance level. The correlat~on coeff~c~ents for the regress~on equat~ons for the low-flow season are relat~vely low Th~s was to be expected, because, as d~scussed earl~er, streamflow values for th~s per~od were known to be ~naccurate s~nce they had to be est~mated by personnel from the U s. Geolog~cal Survey on the bas~s of reg~onal streamflow aata and/or personal Judgment because of frequent malfunct~on~ng of gages dur~ng w~nter. However, the streamflow volume ~n th~s per~od represents only about 7 percent of the total annual runoff volume. Because the operat~on study used monthly flow volumes, ~naccurac~es ~nherent ~n the flow synthes~s for the w~nter months do not s~gn~f~cantly affect the overall accuracy of the study and the respect~ve regress~on equat~ons are therefore regarded as acceptable for use ~n the der~vat~on of the long-term streamflow record Table 4-2 presents the lake ~nflows synthes~zed by us~ng these equat~ons and the reverse-rout~ng procedure. The 31 year sequence of ~nflows ~ncludes the June 1959 through August 1971 ~nflows calculated by reverse-rout~ng of outflows plus the May 1949 through May 1959 and the 4-14 I I ~I I . -~ I \ L __ ) TABLE 4-2 CHAKACHAMNA PROJECT OPERATION STUDY H/H H&CF BECHTEL CIVIL&MINERALS INC SF PROJECT 14879001 ALASKA POWER AUTHORITY DATE 11783 PAGE 3 ALTERNATIVE E MCARTHUR SHORT TUNNEL WITH FISH RELEASES INFLOWS TO THE LAKE IN CFS YEAR MAY JUNE JULY AUG SEPT OCT NOV DEC JAN FEB MAR APR AVEYR CALYR 1 4513 10728 15220 11615 6305 2689 802 636 542 488 493 541 4548 1950 2 2055 8572 13194 10548 4521 1761 569 532 495 472 450 631 3650 1951 3 3801 10719 13095 8831 8635 3216 842 699 630 495 467 510 4328 1952 4 2027 8204 12575 9431 3562 2712 865 642 523 477 477 641 3511 1953 5 3992 13247 13355 10808 4505 2002 629 550 527 472 458 541 4257 1954 6 3434 9002 12091 12046 6075 2787 755 619 578 507 466 487 4071 1955 7 2193 6826 12996 9983 5068 1988 595 532 504 475 449 496 3509 1956 8 2936 7475 14601 10235 5940 2053 583 565 569 536 505 598 3883 1957 9 4393 14817 13149 10405 6910 2707 793 562 569 510 489 675 4665 1958 10 2496 9930 10163 8691 3452 1896 526 483 426 468 44'3 526 3292 1959 11 3120 9459 10388 11731 3662 1370 654 508 400 307 267 393 3522 1960 12 3637 6837 11209 9337 3145 1439 799 870 877 589 470 346 3296 1961 13 1881 7983 12808 10899 622!:> 1586 84J 696 633 541 471 470 3753 1962 14 1265 7925 13149 10411 5542 1197 863 613 498 357 315 337 3539 1963 15 1801 4735 13249 12208 5847 2086 930 710 364 435 332 477 3598 1964 16 1830 8093 10700 11798 4246 1245 909 662 419 219 337 398 3405 1965 17 1286 3490 11633 11929 10802 2114 597 466 388 336 350 410 3650 1966 ~ 18 1893 8072 10303 9974 6608 1953 910 313 531 449 384 880 3523 1967 I 19 2030 8761 14931 15695 6191 2040 1215 571 534 510 467 630 4465 1968 1-' l11 20 2996 7808 13117 11257 2793 976 689 612 485 486 500 652 3531 1969 21 1948 9271 12478 7297 2793 3057 1215 601 497 504 550 899 3426 1970 22 2265 6789 10360 7986 2734 1359 742 460 3g4 441 513 1275 2943 1971 23 4063 12672 13695 16680 5075 3181 1090 736 581 531 492 479 4940 1972 24 3468 8228 13490 9263 5012 2396 679 514 495 492 480 586 3759 1973 25 2131 7457 8850 7809 2794 2527 740 623 558 526 501 554 2923 1974 26 4215 6248 6781 6159 6850 3059 909 530 498 485 485 489 3059 1975 27 4784 10649 10889 6802 5107 3136 814 622 544 524 498 625 3750 1976 28 5283 8587 8304 6494 4947 3917 1058 1055 1044 773 606 606 3556 1977 29 5335 19864 13898 11224 6059 3709 922 700 609 537 509 558 5327 1978 30 5387 7917 10146 7865 4513 3258 708 701 597 562 547 713 3576 1979 31 6776 8514 8958 9157 4572 4471 1412 882 762 718 647 810 3973 1980 MEAN 3201 8996 11928 10147 5177 2383 828 621 551 491 465 588 3781 MAX 6776 19864 15220 16680 10802 4471 1412 1055 1044 773 647 1275 5327 MIN 1265 3490 6781 6159 2734 976 526 313 364 219 267 337 2923 September 1971 through Apr1l 1979 1nflows calculated from the regress1oh equat1ons. 4.5 Power Stud1es Dur1ng the 1981 proJect stud1es four bas1c alternat1ve proJect layouts were developed and des1gnated Alternat1ves A, B, C and D as descr1bed 1n Sect1on 3.3 of th1s report. Power stud1es also performed dur1ng 1~81 for these four alternates were based on the ll complete calendar years (January l, 1960 through December 31, 1970) of Chakachamna Lake 1nflow set forth 1n Table 4-1. Dur1ng the 1982 stud1es, the recommended Alternat1ve E, also descr1bed 1n Sect1on 3 3, was developed, as was the 31 year sequence of 1nflow to Chakachamna Lake wh1ch was used dur1ng the 1982 power stud1es for each of the alternat1ves A through E. The power operat1on stud1es were performed to determ1ne generated f1rm and secondary energy, flow releases, and the fluctuat1ons 1n the water surface elevat1on of Chakachamna Lake for a range of 1nstalled capac1t1es for each of the f1ve proJect alternat1ves The stud1es were made us1ng a computer program that performs sequent1al rout1ng of the der1ved monthly 1nflows wh1le sat1sfy1ng power demands, proJected 1n-stream flow requ1rements, and phys1cal system constra1nts. Power demands were 1n accordance w1th a plant load factor of 0.5, and the monthly var1at1ons 1n peak demand l1sted 1n Table 4-3. As adv1sed by APA, these demands are those be1ng used 1n the evaluat1on of sources of power alternat1ve to that of the Chakachamna Hydroelectr1c ProJect. The 1n-stream flow requ1rements, l1sted 1n Table 4-4, represent prov1s1onal m1n1mum monthly flows to be 4-16 r 1 I I I IJ r r I I I I ) r~ \ \ l ,~ ' I I I l I \ I I I I I I 1 1 I "-! : f I I '~~ TABLE 4-3 MONTHLY PEAK POWER DEMANDS USED IN POWER STUDIES MONTH January February March Aprll May June July August September October November December MONTHLY PEAK DEMAND (Percent of Annual Peak Demand) 92 87 78 70 64 62 61 64 70 80 92 100 Source. Sus1tna Hydroelectrlc ProJect Development Selectlon Report Appendlx D, Table D 1 (Second Draft, July 1981) 4-17 ~ 'IABLE 4-4 PROVISIONAL MINIMUM RELEASES FOR INSTREAM FLOW IN CHAKACHATNA RIVER DOWNSTEEAM FROM CHAKACHAMNA LAKE OUTLET FOR USE IN POWER STUDIES MONTH MC ARTHUR TUNNEL CHAKACHATNA TUNNEL MCARTHUR TUNNEL DEVELOPMENT DEVELOPMENT DEVELOPMENT ALTERNATIVE B ALTERNATIVE D ALTERNATIVE (CFS) * (CFS) (CFS)* January 365 30 365 February 343 30 357 March 345 30 358 Apr1l 536 30 582 May 1,094 30 1,094 June 1,094 30 1,094 July 1,094 30 1,094 August 1,094 30 1,094 September 1,094 30 1,094 October 365 30 365 November 365 30 365 December 360 30 363 * Cr1ter1a used to determl.ne f1sh 1nstream flow release Aprl.l through September -1094 cfs or 1nflow to lake whl.chever l.S less October through March -365 cfs or 1nflow to lake whl.chever l.S less 4-18 E I I I~ I I J I I : l ~_j l- -" I I I I I - I I l_) ~ \ I __! L\ I I ~ ' I I ~-I I I I \... _I I I ( _j I ' I L_, I IJ released 1nto the Chakachatna R1ver near the lake outlet as further d1scussed 1n Sect1ons 7.3.2 and 7.3o3 of th1s report. The phys1cal system constra1nts, set forth 1n Table 4-5, are the overall plant eff1c1ency, ta1lwater elevat1on, and head loss for the hydraul1c condu1ts. In the power stud1es water was drafted from lake storage whenever the monthly 1nflows were 1nsuff1c1ent to meet the power demand It was assumed that sp1ll, or d1scharge of water from the lake 1nto the Chakachatna R1ver 1n excess of the tentat1ve 1nstream requ1rements would occur whenever the lake water level exceeded elevat1on 1,128 feet, for alternat1ves A through D, and 1155 for alternat1ve E The secondary energy 1s that wh1ch can be generated by plant capac1ty 1n excess of that needed to meet the load carry1ng capab1l1ty, us1ng water wh1ch otherw1se would have sp1lled For each of the alternat1ves cons1dered for development of the proJect, a range of 1nstalled powerplant capac1t1es was tested 1n order to establ1sh the 1nstalled capac1ty that would make the most use of all water ava1lable for power generat1on w1thout draw1ng the lake level below a g1ven m1n1mum elevat1on. Th1s m1n1mum was taken as elevat1on 1,014 feet for alternat1ves A through D and elevat1on 1,085 for alternat1ve E respect1vely. The lake was assumed to be full at the beg1nn1ng of each run. 4 6 Results The results of the power stud1es l1sted 1n Table 4-6 show that, on the bas1s of the 11 calendar years of 4-19 ALTERNATIVE A B c D E Note Q = TABLE 4-5 POWERPLANT SYSTEM CONSTRAINTS FOR ALTERNATIVE PROJECT DEVELOPMENTS PLANT PLANT AVERAGE HEAD LOSS IN EFFICIENCY FACTOR TAILWATER HYDRAULIC CONDUITS (%) ELEVATION (FT.) (FT.) 85 0 50 210 0 0000024 X Q2 85 0.50 210 0 0000024 X Q2 85 0.50 400 0.0000028 X Q2 85 0.50 400 0 0000028 X Q2 85 0.45 210 0.0000024 X Q2 Flow Ln cubLc feet per second 4-20 I I I I ~ I , I I i l~_l I -, TABLE 4-6 POWER STUDIES SUMMARY Development Installed Average Annual Energy Average Annual Flow Alternatl.ve CapacJ.ty Fl.rm Secondary Power DJ.versJ.on Provl.sl.onal A B c D E Note (MW) (GWh) (GWh) (CFS) In stream (CFS) 400 1752 153 3322 0 330 1446 124 2701 679 300 1314 139 3230 0 300 1314 130 3239 30 330 1301 290 2274 685 Perl.od of record January 1, 1960 to December 31, 1970 Average annual J.nflow to Chakachamna Lake 3547 cfs (2.6 ml.llJ.on AF) AlternatJ.ves A, B -Development vl.a McArthur tunnel Alternatl.ves C & D -Development vl.a Chakachatna tunnel Perl.od of record May 1, 1949 to Aprl.l 30, 1979 Average annual J.nflow to Chakachamna Lake 3781 cfs (2.7 mJ.llJ.on AF) AlternatJ.ve E -Development vl.a McArthur Tunnel Power dl.versJ.on flows are the flows needed to meet f1rm energy requJ.rements. 1nflow, and w1th the parameters used 1n the stud1es, the opt1mum development v1a the McArthur Tunnel could support a powerplant of 400 MW 1nstalled capac1ty when all controlled water 1s used for power generat1on as 1n Alternat1ve A. At 50% plant factor, th1s prov1des an average annual 1,752 GWh of f1rm energy. The prov1s1onal 1nstream flow requ1rements of Alternat1ve B d1scussed 1n Sect1on 7 3 2 of th1s report represent about 19% of the average annual flow 1n the Chakachatna R1ver dur1ng the per1od of record. If that amount of water 1s reserved for 1nstream flow, the 1nstalled capac1ty of powerplant that could be ]Ust1f1ed at the M~rthur R1ver would be reduced to 330 MW and the f1rm average annual energy would be 1446 GWh For development v1a the Chakachatna tunnel, the opt1mum power development us1ng all controlled water for power generat1on, Alternat1ve C, would have an 1nstalled capac1ty of 300 MW and f1rm annual average energy would be 1314 GWh for a 50% plant factor The prov1s1onal m1n1mum 1nstream flow reservat1ons 1n Alternat1ve D, d1scussed 1n Sect1on 7.3.3 of th1s report, represent less than 1% of the average annual flow dur1ng the per1od of record. Thus, the 1nstalled capac1ty and f1rm energy 1n Alternat1ve D for pract1cal purposes would rema1n the same. There would however be about 15% reduct1on 1n the amount of secondary energy that could be generated. Alternat1ves A through D cannot f1rmly support the capac1t1es determ1ned from the 11 years of 1nflow dur1ng the 1981 stud1es and the recommended Alternat1ve E cannot f1rmly support 330 MW at 50% plant factor due to two consecut1ve dry years (1973-74) that occur dur1ng tne 31 years of 4-22 I I : I I I r~ I I r r l \ L ~ 1----, I I 1'-..-J I ~ LJ I l I I_~ \-I ,l I I \ , I I ) -} correlated lake 1nflow These two years do not occur 1n the 11 calendar years (1960-1970) of 1nflow used 1n the 1981 power stud1es for Alternates A through D and some add1t1onal ana~yses should be made 1n future stud1es of the proJect. Us1ng the 31 years of lnflow, and 330 MW 1nstalled capac1ty, Alternate E could produce 1301 GWh at 45% load factor. Var1at1ons 1n Lake Water Level The var1at1ons 1n lake water-surface elevat1on calculated at the end of the month dur1ng the course of the power stud1es for each of the f1ve alternat1ves and cases l1sted 1n Table 4-6 are shown 1n the computer output 1ncluded 1n the Appendlx to Sect1on 4 0, and are also plotted 1n F1gures 4-4 and 4-5. 4-23 til z pqo H <d ~ A\.LVNe:!3..l..i~ ~E-t <;:s ..;t til~ I ..;t \:1 '3AU..VN'd"31."'1~ ------~> > ~ H....:l ~~ 8 ~~ H }:1V3.A C!Va N 31"V 'J ~....:I rz.. OLGI S<? QO] L~ <!)a; ~6) ?., <e? (!., \") O.,GI ~§ 0001 . OZOI r ;., ~ a'\ J> A ' ' ·"~ D. r\ ... OvO\ "f. ~' '\ ,r,, "' ~ . ~ f\ ,, ~ ~ ~ rn \ ~ I ' ~ J'J \ N r f-.· ~ II ,, l 0~01 ' ~ 0 I 11 z. \ I ~ 090l -z "f1 m m I 001 i -i 1-\J OZH u 'u v ~ \j \J \J u \J w ovl t -) I I ~ __ j. I I ~~I ~~-, "---1 -_J CJU I I .___ ~I ~) I \40 n ~ ~ ~ ~ ~ ~~ f'\ n n i-112.0 I\ ill U1 I u. 1100 z - z lOBO t 0 -~ ::> 10~0 ill \ \ _j u1 \ \ \ \ \ w ~040 \ ~ ~ \ " ' < .J !020 rooo §~ 19'='0 "'I G:,2 (o3 Co4 ~5 ~~ 61 b8 ( ~9 1970 1-:!:j I:'"' I:%:! CALENDAR YEAR H 1:%:1~ ~ ~~ t"'H <~ ALTERNAT\VE. c ~ ?dC/) I ln HC":l P> i-3Qo _ __, ____ AL T E.R NAT\VE:. 0 H I 00 z I Cll GEOLOGIC INVESTIGATIONS 1 I I i I ,-l \ i I I I I I I I I r '! : I I I I I I I 1 __ 1 r 1 I I I_) - 1 I I I L' il I I I ~ 5 0 5 1 5 1.1 GEOLOGIC INVESTIGATIONS Scope of Geolog1c Invest1gat1ons Techn1cal Tasks The scope of the geolog1c 1nvest1gat1ons planned for the Chakachamna Hydroelectr1c ProJect Feas1b1l1ty Study 1ncludes f1ve techn1cal tasks (1) Quaternary geology, (2} Se1sm1c geology, (3} Tunnel al1gnment and powerplant s1te geology, (4} Construct1on mater1als geology, and (5) Road and transm1Ss1on l1ne geology These tasks were 1dent1f1ed and scopes def1ned so that, upon co~plet1on of the 1nvest1gat1ons, the 1nformat1on needed to assess the potent1al 1mpact of a range of geolog1c factors on the feas1b1l1ty of the proposed proJect w1ll be ava1lable. If the Chakachamna ProJect 1s JUdged to be feas1ble, add1t1onal geolog1c 1nvest1gat1ons Wlll be requ1red subsequent to the feas1b1l1ty study 1n order to prov1de the deta1led 1nformat1on appropr1ate for actual des1gn At the feas1b1l1ty level, 1t 1s appropr1ate to gather 1nformat1on regard1ng the general character of the geolog1c env1ronment 1n and around the proJect area, Wlth part1cular attent1on to geolog1c hazards and the geology 5-l 5 1 1 1 of spec~f~c fac~l1t~es s~t1ng locat1ons The Chakacharnna ProJect, as presently conce1ved, does not 1nclude fac1l1t~es such as large darns that would 1ncrease the r1sks assoc1ated w~th geolog1c hazards that are naturally present 1n the proJect area The geolog1c tasks were planned 1n recogn1t1on of the above and were des1gned to focus on geolog1c factors that may 1nfluence the techn1cal feas1b1l1ty, the operat1ng rel1ab1l1ty, and/or the cost of the proposed proJect The work on the geology tasks began ~n August 1981 but the rnaJOr1ty of the work w~ll take place 1n future feas1b~l1ty level 1nvest1gat1ons Th1s report 1ncludes a summary of the work planned for the geolog1c 1nvest1- gat1ons (Sect1on 5 1 1) and the schedule for each geology task (Sect1on 51 2), surnrnar1es of the work completed for the Quaternary geology (Sect1on 5 2) and se1srn1c geology (Sect1on 5 3) tasks, and some prel~rn1nary commentary on geolog1c cond1t1ons ~n the proJect area ~n Sect~on 7 0 The commentary and any tentat1ve conclus~ons presented here are subJect to rev~s~on as the proJect work cont1nues 1n the future Quaternary Geology The Quaternary geology task was des1gned to ~nclude an assessment of the glac~ers and glac~al h1story of the Chakacharnna Lake area, an ~nvest~gat1on of the Mt Spurr and assoc1ated volcan1c centers, and a study of the slope cond1t~ons near s1tes proposed for proJect fac~l1t1es A study of the glac1ers was JUdged to be appropr1ate because 5-2 I~ I I J I ~ I I I I \ : ~ I c 1 I L ~ I I I IL I I I I I ) I I I I I I l - I I I I ( I I I l I (1) movement of the term1nus of Barr1er Glac1er 1nfluences the water level 1n Chakachamna Lake and any structures to be bu1lt near the lake outlet, ( 2 ) ( 3 ) the poss1b1l1ty that changes 1n the term1nal pos1t1on of Blockade Glac1er could alter the dra1nage at the mouth of the McArthur R1ver Canyon, and quest1ons regard1ng the 1nfluence of other glac1ers 1n the study area on the s1ze and hydrolog1c balance of Chakachamna Lake ( In add1t1on, knowledge of the ages of geornorph1c surfaces 1s 1mportant to the assessment of poss1ble se1sm1c hazards and such knowledge depends on an understand1ng of the glac1al geology The s1mple presence of Mt Spurr, an act1ve volcano, at the eastern end of Chakachamna Lake prov1des a clear rat1onale for 1nvest1gat1ng the volcan1c h1story and potent1al volcan1c hazards of the proJect area Of part1cular 1nterest 1s the poss1b1l1ty that lava flows or volcan1c mudflows (a poss1b1l1ty 1ncreased by the glac1er 1ce on Mt Spurr) could enter the lake and produce large waves, an 1ncrease 1n lake level, and/or a change 1n cond1t1ons at the lake outlet or on the upper reaches of the r1ver In add1t1on, the poss1ble 1mpact of a dark, heat-absorb1ng layer of volcan1c eJecta on the glac1ers' mass balance, and thus the lake's hydrolog1c balance 1s of 1nterest 5-3 5 1 1 2 Chakachamna Lake, Chakachatna R1ver Canyon, and McArthur R1ver Canyon are all bordered by steep slopes that may be subJect to a var1ety of types of slope fa1lure A large landsl1de 1nto the lake could change the usable volume of water stored 1n the lake and could alter cond1t1ons at I I the proposed lake tap and at the natural outlet from the 1 1 I lake Potent1al outlet portal and surface powerhouse s1tes 1n the r1ver canyons are all on or 1mmed1ately adJacent to steep slopes Both the 1ntegr1ty of and access to these fac1l1t1es could be 1mpa1red 1n the event of landsl1de and rockfall act1v1ty Because of the concerns 1nd1cated above, the Quaternary geology task was des1gned to 1nvest1gate the t1m1ng and s1ze of past glac1al fluctuat1ons, the frequency and type of volcan1c act1v1ty, and the slope cond1t1ons 1n order to prov1de an est1mate of poss1ble future events that could 1nfluence the costs and operat1ng performance of the proposed hydroelectr1c proJect In add1t1on, th1s task should prov1de 1nformat1on regard1ng the poss1b1l1ty of the proJect destab1l1z1ng the lake outlet by produc1ng or allow1ng changes 1n Barr1er Glac1er Se1sm1c Geology The se1sm1c geology of the Chakachamna Lake area 1s of 1nterest because southern Alaska 1s one of the most se1sm1cally act1ve areas 1n the world Potent1al se1sm1c hazards of d1rect concern to the proposed hydroelectr1c proJect 1nclude surface fault1ng, ground shak1ng, se1sm1cally-1nduced slope fa1lure, lake se1che, and l1quefact1on Spec1f1cally, the se1sm1c geology task was des1gned to 1nvest1gate the poss1b1l1ty of act1ve faults 1n the 1mmed1ate v1c1n1ty of the proposed fac1l1t1es, to 5-4 I I I I I -1 I I I I I ( I I I I I I I I I I assess the locat1on and act1v1ty of reg1onal faults (e g ' Castle Mounta1n, Bru1n Bay), and to est1mate the type and 1ntens1ty of se1sm1c hazards that may be assoc1ated w1th these faults and w1th the subduct1on zone The se1sm1c geology 1nvest1gat1ons were planned to max1- m1ze the use of ex1st1ng 1nformat1on by follow1ng a sequence of subtasks that become 1ncreas1ngly s1te I spec1f1c as the work proceeds The pr1mary elements 1n the sequence are o l1terature rev1ew o remote sens1ng 1magery analys1s o f1eld reconna1ssance 0 low-sun-angle a1r photo acqu1s1t1on and analys1s o deta1led f1eld stud1es The data produced by the above sequence 1s requ1red to assess d1rectly the surface fault1ng hazard and for 1nput to the probab1l1st1c assessment of ground mot1on para- meters In order to develop approx1mate ground mot1on spectra for the var1ous elements of the proJect, ex1st1ng ground mot1on 1nformat1on developed for other proJects 1n southern Alaska w1ll be rev1ewed and mod1f1ed, as appropr1ate A s1mpl1f1ed evaluat1on of the l1quefact1on potent1al of the transm1ss1on l1ne al1gnment should also be carn.ed out 5-5 5 1 1 3 5 1 1 4 Tunnel Al1gnment and Powerplant S1te Geology The scope of work for th1s task should be based on the need to assess the feas1b1l1ty of construct1ng a lake tap 1n Chakachamna Lake, a long tunnel, and a powerhouse as the pr1mary components of the proposed hydroelectr1c development Because of the steep mounta1nous terra1n above the tunnel al1gnment, the tunnel feas1b1l1ty study should be planned around the mapp1ng of bedrock exposures 1n the mounta1ns and product1on of a str1p map, dr1ll1ng would be l1m1ted to the powerhouse s1te dur1ng the feas1- b1l1ty 1nvest1gat1ons The str1p map should focus on those bedrock character1st1cs that determ1ne the techn1cal and econom1c feas1b1l1ty of tunnell1ng Geophys1cal techn1ques should be used to assess the lake bottom bedrock and sed1ment character1st1cs at and near the proposed lake tap and subsurface cond1t1ons at the proposed powerhouse s1te All reasonably poss1ble surface powerplant and outlet portal s1tes are on or adJacent to h1gh, steep slopes Hazards such as landsl1des, rockfalls, and avalanches, wh1ch are a part1cular concern 1n se1sm1cally act1ve areas, should be assessed dur1ng the feas1b1l1ty study Construct1on Mater1als Geology The proposed Chakachamna Hydroelectr1c Pro]ect w111, 1f constructed, requ1re aggregate for concrete, road con- structlon, and construct1on of the transm1ss1on l1ne In add1t1on, rockf1ll w1ll be requ1red for the low d1ke at the lake outlet and boulder r1p-rap may be requ1red at the outlet portal and outfall from the powerhouse Th1s task should be planned to y1eld 1nformat1on about potent1al 5-6 I I I I I I I I I I I I I I 1 I ~ I I I, I I I' I I I I 1:-I I ,I I ,\ I I I I IL I I I I t 5 1.1 5 5 1 2 5 1 2 1 aggregate sources at the powerhouse-outlet portal s1te, along the road, and along the transm1ss1on l1ne al1gnment Road and Transm1ss1on L1ne Geology Geolog1c cons1derdt1ons w1ll be 1mportant 1n the assessment of the road and transm1ss1on l1ne routes Th1s task w1ll use aer1al photograph analys1s and reconna1ssance-1evel f1eld stud1es 1n order to prov1de 1nformat1on on the general character of the al1gnments The task plans should g1ve part1cular attent1on to r1ver cross1ngs, wh1ch ma1 be subJect to large floods, and to wetland areas where spec1al construct1on techn1ques may be requ1red Schedule The 1981 geolog1c f1eld program d1d not commence unt1l late August that year and was therefore relat1vely l1m1tea 1n scope, cover1ng only the Quaternary geology and part of the se1sm1c geology tasks Future 1nvest1gat1ons should concentrate on the rema1n1ng geolog1c tasks as d1scussed below Quaternary Geology All of the Quaternary geology f1eld stud1es were e1ther of a reg1onal nature or d1rected at targets that would not vary as a funct1on of f1nal conf1gurat1on of the proJect fac1l1t1es Therefore, 1t was poss1ble to complete the f1eld work planned for th1s task Some add1t1onal rev1ew of unpubl1shed data, such as that held by the U S Geolog1cal Survey 1n Fa1rbanks, and d1scuss1ons w1th geolog1sts who have worked 1n the 5-7 5 1 2 2 5 1 2 3 Chakachamna area rema1n to be completed Although several 1mportant 1mpl1cat1ons w1th respect to the proposed hydroelectr1c proJect have been 1dent1f1ed and some tentat1ve conclus1ons may be drawn, add1t1onal analyses and d1scuss1ons are needed before the conclus1ons can be f1nal1zed Se1sm1c Geology As d1scussed 1n Sect1on 5 1 1 2, the se1sm1c geology task 1s des1gned around a sequence of 1nvest1gat1ons, each of wh1ch bu1lds on the preced1ng ones Because of th1s character1st1c, the se1sm1c geology task demands a certa1n amount of elapsed t1me and cannot be speeded up by add1ng add1t1onal staff Dur1ng 1981 1t was poss1ble to coMplete the l1terature rev1ew, analys1s of ex1st1ng remote sens1ng 1magery, f1eld reconna1ssance, and the acqu1s1t1on and 1n1t1al analys1s of the low-sun-angle aer1al photography The deta1led f1eld stud1es and ground mot1on assessment w1ll be conducted dur1ng future feas1b1l1ty study work Tunnel Al1gnment and Powerplant S1te Geology No f1eld 1nvest1gat1ons were conducted for th1s task 1n 1981 because the var1ous tunnel al1gnment locat1ons and conf1gurat1ons to be stud1ed were not 1dent1f1ed pr1or to I I I I 1 I I I I I j I I I complet1on of the 1981 f1eld season All of the geolog1c , 1 and geophys1cal 1nvest1gat1ons planned for th1s task should be completed dur1ng future feas1b1l1ty study work I I I I I I 1 I 5-8 I I I I I I I r I~~ I I ~I ~I ~ I I I I ~~I ! l I I I I \ 5 1 2 4 5 1 2 5 5 2 Construct1on Mater1als Geology The work for th1s task w1ll be conducted dur1ng future feas1b1l1ty study work Road and Transm1ss1on L1ne Geology The work for th1s task w1ll be conducted dur1ng future feas1b1l1ty study work Quaternary Geology The Quateinary, approx1mately the ~ast 2 m1ll1on years of geolog1c t1me, 1s commonly subd1v1ded 1nto the Ple1stocene and the Holocene (most recent 10,000 years) Although the Ple1stocene 1s generally equated to the glac1al age and the Holocene w1th post-glac1al t1me, such a d1st1nct1on 1s less clear 1n southern Alaska where the mounta1ns st1ll conta1n extens1ve glac1ers The Quaternary was a t1me of extreme and var1ed geolog1c act1v1ty 1n southern Alaska In add1t1on to the extens1ve glac1al act1v1ty and assoc1ated phenomena, the Quaternary was also a t1me of mounta1n bu1ld1ng and volcan1c act1v1ty The products of these and other geolog1c processes that were act1ve dur1ng the Quaternary, and are st1ll act1ve today, are broadly present 1n the Chakachamna Lake area Although the geolog1c 1nvest1gat1ons for th1s feas1b1l1ty study cons1der a broad range of top1cs that fall under the general head1ng of Quaternary geology, th1s task was planned to address three spec1f1c top1cs 5-9 5 2 1 5 2 1 1 (1) glac1ers and glac1al geology, ( 2) Mt Spurr volcano, and (3) slope cond1t1ons In add1t1on, the se1sm1c geology task (Sect1on 5 3) 1s des1gned to focus on Quaternary and h1stor1c fault act1v1ty and se1sm1c1ty and 1s h1ghly dependent on an understand1ng of the glac1al h1story of the area for temporal data For the Quaternary geology task of the Chakachamna study, f1eld worh cons1sted of a twelve-day reconna1ssance dur1ng wh1ch all three pr1mary top1cs of 1nterest (above) were stud1ed When comb1ned w1th 1nformat1on ava1lable 1n the open l1terature and that ga1ned through 1nterpretat1on of aer1al photography, the f1eld reconna1ssance prov1des a bas1s for assess1ng the potent1al 1mpact of the glac1ers, volcano, and slope cond1t1ons on the proposed hydroelectr1c proJect Glac1ers and Glac1al Geology Reg1onal Glac1al Geolog1c H1story At one t1me or another dur1ng the Quaternary, glac1ers covered approx1mately half of Alaska (Pewe, 1975) Prev1ous 1nvest1gat1ons have demonstrated that the Cooh Inlet reg1on has had a complex h1story of mult1ple glac1at1on (M1ller and Dobrovolny, 1959, W1ll1ams and Ferr1ans, 1961, Karlstrom, 1964, Karlstrom and others, 1964, Tra1ner and Waller, 1965, Pewe and others, 1965, 5-10 I~\ I I I I I I ~ I I I I I I~ I I I I I I _I 1\ I I ( I \ I u ( ! Schmoll and others, 1972) The current understand1ng of the reg1on's glac1al h1story 1s based on 1nterpretat1on of the morphostrat1graph1c record 1n assoc1at1on w1th relat1ve and absolute age dat1ng and other Quaternary stud1es The complex h1story 1s recorded 1n glac1al, fluvial, lacustr1ne, mar1ne, and eol1an sed1ments that have been stud1ed pr1mar1ly 1n the1r surface exposures where they can be assoc1ated w1th spec1f1c landforms Although more recent work has led to mod1f1cat1on and refinement of Karlstrom's (1964) h1story of glac1at1on 1n the Cook Inlet reg1on, that work st1ll prov1des a good general overv1ew and, except where noted, serves as the bas1s for the follow1ng summary On at least f1ve separate occas1ons dur~ng the Quaternary, the glac1ers 1n the mounta1ns that surround Cook Inlet have expanded onto the Cook Inlet lowlands where they coalesced to cover much or all of the lowland w1th 1ce Ev1dence for the two oldest recogn1zed glac1at1ons (Mt Sus1tna, car1bou Hllls) cons1sts dominantly of errat1c boulders and scattered remanants of t1ll at h1gh elevat1on s1tes around the marg1ns of the lowland Ev1dence for the next glac1at1on, the Eklutna, 1ncludes mora1nes and t1ll sheets that demonstrate the coalescence of 1ce from var1ous source areas to form a Cook Inlet p1edmont glac1er The ava1lable ev1dence suggests several thousand feet of 1ce covered VIrtually all of the Cook Inlet lowland dur1ng these early glac1at1ons The next two glac1at1ons, the Kn1k and the Naptowne, correspond to the Early W1scons1n and Late W1scons1n glac1at1ons of the midwestern Un1ted states, respectively Thus, the Naptowne glac1at1on of the Cook 5-11 Inlet reg1on correlates, 1n general, w1th the Donnely (Pewe, 1975) and McK1nley Park (TenBr1nk and R1tter, 1980, TenBr1nk and Waythomas, 1n preparat1on) glac1at1ons reported from two areas on the north s1de of the Alaska Range Dur1ng the Kn1k and Naptowne glac1at1ons 1ce aga1n advanced onto the Cook Inlet lowland, but the 1ce d1d not completely cover the lowland as 1t apparently d1d dur1ng the earl1er glac1at1ons Even at the glac1al I J ' I I I I' I I I max1ma, port1ons of the lowland were 1ce free, such areas (~ were commonly the s1tes of large 1ce-dammed lakes that have been stud1ed 1n some deta1l (M1ller and Dobrovolny, 1959, Karlstrom, 1964) The max1mum 1ce advance dur1ng the Naptowne glac1at1on 1s recorded by d1st1nct end mora1ne complexes located near the mouths of the maJor valleys that dra1n the Alaska Range and by mora1nes on the Kena1 lowland The mora1nes on the Kena1 lowland are of part1cular 1nterest because they were, at least 1n part, formed by the Trad1ng Bay 1ce lobe, wh1ch or1g1nated 1n the Chakachatna-McArthur r1vers area and advanced across Cook Inlet at the t1me of the Naptowne max1mum Karlstrom (1964) reported on these features on the Kena1 lowland 1n some deta1l Karlstrom (1964) used a comb1nat1on of rad1ocarbon dates and relat1ve-age dat1ng techn1ques to develop a chronology for the Cook Inlet glac1at1ons Accord1ng to Karlstrom, the Naptowne glac1at1on cont1nued, although w1th decreas1ng 1ntens1ty, past the Ple1stocene-Holocene boundary (generally taken as be1ng near 10,000 years before present [ybp]), through the Cl1mat1c Opt1mum, to the beg1nn1ng of Neoglac1at1on (see Porter and Denton, 1967) Recent work on the north s1de of the Alaska Range has produced a well-dated chronology for the McK1nley 5-12 ( I I \~I I I I I jl I I I I I I I \ I I I I - L\ I '~ J Park glac1at1on (TenBr1nk and R1tter, 1980, TenBr1nk and waythomas, 1n preparat1on) stad1al events at That chronology shows maJor ( 1) ( 2) ( 3) 25,000-17,000 ybp (max1mum advance at about 20,000 ybp), 15,000-13,500 ybp, 12,800-11,800 ybp, and (4) 10,500-9,500 ybp Recogn1z1ng the d1fferences 1n 1ce extent and other factors between the Cook Inlet reg1on and the north s1de of the Alaska Range, the TenBr1nk chronology 1s probably reflect1ve of the t1m1ng of the pr1mary Naptowne stad1al events Dates from the Cook Inlet reg1on proper have yet to y1eld such a clear p1cture, probably because of the greater complex1ty of the cond1t1ons and thus the record there Follow1ng the Naptowne glac1at1on (about 9,500 ybp by TenBr1nk's chronology, as late as 3,500 ybp accord1ng to Karlstrom, 9164), glac1al advances 1n the Cook Inlet reg1on have been l1m1ted to rather small-scale fluctuat1ons that have extended only up to a few m1les beyond present glac1er term1n1 Karlstrom (1964) referred to these Neoglac1al advances as the Alaskan glac1at1on, wh1ch he d1v1ded 1nto two d1st1nct per1ods of advance (Tustumena and Tunnel) and further subd1v1ded 1nto three and two short-term ep1sodes, respect1vely Accord1ng to Karlstrom (1964) these Neoglac1al events range 1n age from approx1mately 3,500 ybp to h1stor1c fluctuat1ons of the last several decades 5-13 5 2 1 2 Two po1nts of part1cular 1nterest regard1ng Neoglac1at1on 1n Alaska emerged from the l1terature rev1ew (1) the 1dea that n the youngest maJor advance typ1cally was the most extens1ve of the Neoglac1at1on" (Porter and Denton, 1967, p 187), and (2) Karlstromus (1964) suggest1on that, at least 1n the mounta1ns around the marg1ns of the Cook Inlet reg1on, there was no d1st1nct h1atus between the last small Naptowne readvance and the f1rst Neoglac1al advance These po1nts w1ll be addressed 1n the follow1ng sect1on ProJect Area Glac1al Geolog1c H1story The reconna1ssance-level 1nvest1gat1ons conducted for the Chakachamna study conf1rm the general p1cture for the proJect area presented by Karlstrom (1964) The area exam1ned dur1ng the f1eld reconna1ssance 1s 1ndicated on F1gure 5-l Although a rather broad area was Included 1n the study area, most of the field work took place In the I I I I I I I I I 1 I I Chakachamna Lake basin, along the Chakachatna River, and I 1 on the southern slopes of Mt Spurr Most of the study area was covered by glacier Ice during the max1mum stand of the Naptowne-age glac1ers Based on Karlstrom 1 s (1964) work, It would appear that only h1gh, steep slopes and local elevated areas were not covered by Naptowne ICe W1thin the area examined In the field, the upper l1m1t of Naptowne Ice IS generally clearly def1ned, particularly In the area between Capps Glac1er and 5-14 ~ I I I ' ' . -..::· ~ EXPLANATION PLACE NAMES AND LOCATIONS WITHIN THE QUATE RNARY GEOLOGY REOONN AISSANCE AREA IN VESTIGATED BY WOODWARD-CLYDE CONSULTANTS DURING THE 1081 FIELD SEASON. to " SCAlE IN MILES I I I L I t ' I I J I ~r I \ I~ I I ' I I I (_\ if I \ I 1 r I I Ll 1 I Ll \ ( I I Blockade Glac1er, at and east of the range front (Flgure 5-l) In th1s area lateral mora1nes produced dur1ng the max1mum stand of Naptowne 1ce (25,000-17,000 ybp) are d1st1nct and traceable for long d1stances, younger Naptowne lateral and term1nal mora1nes are also present The largest area that was not bur1ed by Naptowne 1ce and wh1ch was observed dur1ng f1eld reconna1ssance 1s located h1gh on the gentle slopes east of Mt Spurr, between Capps Glac1er and Stra1ght Creek The two older surfaces r (Knlk and (?) Eklutna) observed 1n th1s area (F1gure 5-l) correspond well to the 1deas presented by Karlstrom (1964) Not only are mora1nes mark1ng the Naptowne max1mum present, but a large number of mora1nes produced dur1ng subsequent stad1al advances or recess1onal st1llstands are also present These features demonstrate that even at the Naptowne max1mum, 1ce from Capps Glac1er and other glac1ers to the north d1d not coalesce w1th 1ce com1ng from the Chakachatna canyon, except poss1bly near the coast The Chakachatna 1ce and that 1ssu1ng from the McArthur R1ver Canyon and Blockade Glac1er d1d JOln, however, to produce Karlstrom's (1964) Trad1ng Bay 1ce lobe That 1ce lobe covered the alluv1al flat that, at the coast, extends from Gran1te Po1nt to West Foreland From the present coast, the Trad1ng Bay lobe (accord1ng to Karlstrom, 1964) extended across Cook Inlet to the Kena1 lowland The complex of mora1nes located between Blockade Glac1er and the Chakachatna R1ver area allow one to trace the slow retreat of Naptowne 1ce As the Trad1ng Bay lobe retreated westward across the 1nlet and then across the Trad1ng Bay alluv1al flats to the mounta1n front, 5-17 separate 1ce streams became d1st1nct As the Naptowne 1ce cont1nued to retreat up the Chakachatna Canyon more and more 1nd1v1dual glac1ers became d1st1nct from one another For example, Brogan Glac1er (1nformal name, F1gure 5-l), separated from the Chakachatna R1ver by a low volcan1c r1dge, produced a recess1onal sequence that 1s 1ndependent of that formed by 1ce 1n the Chakachatna canyon Such a sequence of features 1s less d1st1nct or absent for the other glac1ers between Brogan Glac1er and Barr1er Glac1er W1th1n the Chakachamna Lake bas1n, the ev1dence of Naptowne and older glac1at1ons 1s largely 1n the form of eros1onal features and scattered boulders Naptowne-age t1ll apparently occurs only 1n 1solated pockets w1th1n the lake bas1n and 1ts maJor tr1butary valleys The Naptowne-age surfaces 1n the bas1n are mantled w1th a sequence of volcan1c ashes that averages two to three feet 1n th1ckness The sol1ds are typ1cally developed on these volcan1cs rather than on the underly1ng glaclally-scoured gran1t1c bedrock or t1ll In contrast to the eros1onal topography that character1zes the Naptowne and older surfaces w1th1n the Chakachamna Lake bas1n, Neoglac1al act1v1ty produced prom1nent mora1nes and outwash fans Neoglac1al features were exam1ned at or near the term1n1 of the follow1ng glac1ers, (1) all glac1ers along the south shore of the lake from Shamrock Glac1er to the lake outlet. 5-18 I I -I I I-~ I I \ 1 ,_J \ ) I LJ I ( I I I I l_ I Li r I I I j I_ I I L._/1 r I I~ ( 3 ) - ( 4) ( 5) I I I! I.: Pothole and Harpoon Glac~ers, where they enter the Nag~shlam~na R~ver Valley, all of the glac~ers that flow to the south, southeast, and east from the Mt. Spurr h~ghland (Al~ce Glac~er to Tr~umv~arte Glac~er, F~gure 5-l), and Blockade Glac~er The Neoglac~al h~story of several of these glac~ers ~s d~scussed ~n more deta~l ~n Sect~ons 5 2 1 3 through 5 2 1 5 The Neoglac~al record ~s of part~cular ~mportance to an assessment of poss~ble glac~er fluctuat~ons over the next several decades Return~ng to the two po~nts ra~sed at the end of sect~on 5 2 1 1 (1) In most cases observed ~n the study area, ~t appears that the latest Neoglac~al advance was an extens~ve or more extens~ve than earl~er Neoglac~al advances Th~s ~s ~n a~reement w~th the Porter and Denton (1967) general conclus~on for southern Alaska ( 2) Karlstrom's (1964) chronology suggested a cont~nuous sequence of decreas~ng glac~al advances lead~ng from Naptowne to Neoglac~al t~me. In most parts of the study area ~t was not poss~ble to assess th~s suggest~on However, the mora~nal sequence produced by Brogan Glac~er (F~gure 5-l) and the d~fference ~n the topograph~c character~st~cs of those mora~nes suggest that there was l~ttle, ~f any, h~atus between the youngest Naptowne mora~ne and the oldest Neoglac~al mora~ne 5-19 5 2 1 3 Barr1er Glac1er Barr1er Glac1er or1g1nates 1n the snow and 1ce f1eld h1gh on the slopes of Mt Spurr From there 1t flows down a steep, 1ce-carved canyon to the shore of Chakachamna Lake where 1ts p1edmont lobe forms the eastern end of the lake (F1gures 5-2a, 5-2b) Barr1er Glac1er 1s of part1cular 1nterest to th1s study because the glac1er forms the eastern end of the lake and 1nfluences the s1ze and character of the outlet from the lake Barr1er Glac1er was descr1bed by Capps (1935) 1n h1s report on the southern Alaska Range and was cons1dered 1n several reports on the hydroelectr1c potent1al of Chakachamna Lake (Johnson, 1950, Jackson, 1961, Bureau of Reclamat1on, 1962) G1les (1967) conducted u deta1led 1nvest1gat1on of the term1nal zone of Barr1er Glac1er Most recently, the U S G s 1nvest1gated Barr1er Glac1er as a part of a volcan1c hazards assessment program at Mt Spurr (M1ller, personal commun1cat1on, 1981) G1les• (1967) 1nvest1gat1on of Barr1er Glac1er was the most comprehens1ve to date and was spec1f1cally des1gned to assess the poss1ble 1mpact of the glac1er on hydro- electr1c development of Chakachamna Lake, and v1ce versa That work, wh1ch took place between 1961 and 1966, 1ncluded mapp1ng of the lake outlet area and measurements of hor1zontal and vert1cal movement and of ablat1on on var1ous port1ons of the glac1er Those measurements 1nd1cated that 5-20 I I I I 21 AMNA -:t; :. : 22 LA"l(E ·r I ·' WOODWARD-CLYDE CONSULTANTS / I \ J __-\ ~,..,o ,. _··,.;.', • 1 RE V IS ION '· -. / ,/ \ ·, I A LASKA POWER AUTHORITY CHAKACH AMN A HYDRO ElECTRffij'ROJE C'I · Glacial and Volc an ic Fe atures in the Chakachamna-Chakac ha tna Valley BECHTEL CIVIL & M INERA LS, INC. SAN FRANCISCO CHECKED ..... o O"At'I'IHG Ho REV . Figure 5-2b I -, ) i l _j rl J I \. ,-, I I I ( \ I 1 I I I ~ I I 1~, I I '--~ I 1 I I _! ( 1 ) ( 2) hor~zontal movement ~s ~n the range of 316 to 125 ft/yr on the debr1s-free ~ce and 28 to 1 ft/yr on the debr~s-covered lobe of ~ce that forms the southernmost component of the glac~er's p~edmont lobe complex, and surface elevat~on changes were generally small (+0 8 to -2 9 ft/yr), but ablat~on on the relat~vely debr~s-free ~ce averaged about 35 ft/yr ~n the term~nal zone G~les (1967) ~dent~f~ed f~ve ~ce lobes, two on the debr~s-coveFed ~ce and three on the exposed ~ce, ~n the term~nal zone of Barr~er Glac1er Exam~nat~on of color ~nfrared aer~al photographs for the current study suggests that he def~ned topograph~c, but not necessar1ly glac~olog~cally-funct~onal lobes or ~ce streams For example, on the debr~s-covered port~on of the p~edmont zone, G~les ~dent~f~ed two lobes on the bas~s of a deep dra~nage that cuts across that zone On the a~r photos ~t ~s clear that the dra~nage ~n quest~on parallels and then trends obl~que to the curv~l~near flow features preserved ~n the debr~s mantle The dra~nage does not appear to mark the boundary between two ~ce streams G~les (1967) concluded that the level of Chakachamna Lake ~s controlled by Barr~er Glac~er, spec~f~cally by one 900-ft w~de port~on of debr1s-covered ~ce along the r~ver, that zone reportedly advances southward, ~nto the r~ver channel, at a rate of about 25 ft/yr Although the rate of ~ce movement was apparently relat~vely constant throughout the year, the low stream d~scharge ~n the w~nter allows the glac~er to encroach on the channel but the ~ce ~s eroded back dur~ng the summer Thus, G~les 5-25 suggested that there 1s metastable equ1l1br1um 1n the annual cycle The annual cycle appears to be super- lmposed on a longer-term change such as that suggested by G1les' measurements Observat1ons made dur1ng analys1s of the color 1nfrared (CIR) aer1al photographs and dur1ng the 1981 f1eld recon- nalssance lead to general agreement w1th the conclus1ons produced by prev1ous 1nvest1gat1ons Nonetheless, the CIR a1r photos and extens1ve aer1al and ground-based observat1ons have allowed for the development of several apparently new concepts regard1ng Barr1er Glac1er, those new 1deas may be summar1zed as follows (1) All of the mora1nes assoc1ated w1th Barr1er Glac1er are the products of late Neoglac1al advances of the glac1er and subsequent retreat The large, sharp- crested mora1nes that bound the glac1er complex on the eastern and a port1on of the western marg1n (Flgure 5-2a) mark the locat1on of the 1ce l1m1t as recently as a few hundred years ago (max1mum est1mate) and perhaps as recently as the early to m1ddle part of th1s century Cottonwood trees, wh1ch are the largest and among the oldest of the trees on the d1stal s1de of the mora1ne are approx1mately 300 to 350 years old based on tree r1ng counts on cores collected dur1ng the 1981 f1eld work (locat1on of trees on F1gure 5-2a) Those dates prov1de an upper l1m1t age est1mate The vegetat1on-free character of the prox1mal s1de of the mora1ne and the extremely sharp crest suggest an even more youthful 1ce stand 5-26 I I I -I I r I 1 i ' ) ~ I : \__ I I _j r 1 j I r - 1 I I - ~I l I l_J I I ' ' I I L__l 'l I (2) When Barr~er Glac~er stood at the outermost mora~ne (no 1 above), the term1nal p~edmont lobe was larger than that now present and probably ~ncluded a port1on that floated on the lake, the present r~ver channel south of the glac~er could not have ex~sted 1n anyth~ng near ~ts present form at that t~me The extent of the p~edmont lobe, as suggested here, ~s based on ~nterpretat~on of the flow features preserved on the debr1s-mantled port~on of the term~nal lobe and the proJected cont~nuat~on of the outermost mora1ne (no 1 above) ( 3) The most recent advance of Barr~er Glac~er d~d not reach the outermost mora~ne. It appears that the flow of 1ce was deflected westward by pre-ex~st~ng ~ce and ~ce-covered mora1ne at the po~nt where the glac~er beg~ns to form a p~edmont lobe Th~s pulse was respons~ble for the vegetat~on-free zone of t1ll that mantles the ~ce adJacent to the debr~s-free 1ce and for the large mora~nes that stand above the delta at the northeast corner of the lahe (4) The presently act~ve port~on of Barr~er Glac~er has the same bas~c flow pattern as that descr~bed ~n no 3, above, but the term~nus appears to be retreat- lng The flow of ~ce 1s deflected westward as ~t ex~ts the canyon through wh~ch the glac~er descends the slopes of Mt Spurr The flow pattern ~s clearly v~s~ble on and ~n the debr~s-free ~ce and 1s further demonstrated by the d~str~but~on of the d~st~nct belt of volcan~c debr~s present along the eastern marg~n of the glac~er 5-27 (5) All of the above may be comb1ned to suggest that the large debr1s-mantled (lee-cored) lobe that forms the most d1stal port1on of the glac1er complex, and wh1ch borders the r1ver, 1s now, at least 1n large part, decoupled from the act1ve port1on of the glac1er Th1s 1nterpretat1on 1n turn suggests that the movements measured by G1les (1967) are due to adJustments w1th1n the largely 1ndependent debrls- mantled lobe and to secondary effects transm1tted to and through th1s lobe by the act1ve 1ce upslope (6) In sp1te of the fact that d1s1ntegrat1on of the debr1s-mantled lobe 1s extremely act1ve locally, the lobe appears to be generally stable because remnant flow features are st1ll preserved on 1ts surface The debr1s cover sh1fts through t1me, th1cken1ng and th1nn1ng at any g1ven locat1on as topograph1c 1nvers1on takes place due to melt1ng of the 1ce and slump1ng and water rework1ng of the sed1ment It appears that the rate of melt1ng var1es as a funct1on of the th1ckness of the debr1s cover, w1th a th1ck cover 1nsulat1ng the 1ce and a th1n cover produc1ng accelerated melt1ng Removal of the cover1ng sed1ment along the edge of the r1ver leads to slump1ng and exposure of 1ce to melt-produc1ng cond1t1ons Thus the d1stal port1on of the debrls- mantled lobe that borders the r1ver 1s one s1te of accelerated melt1ng Other areas of accelerated melt1ng are concentrated along dra1nages that have developed w1th1n the chaot1c 1Ce-d1s1ntegrat1on topography 5-28 J I I \ "' I I L_) I I l J j l I~' r 1 ' -I r I \ \- ll I I \ I l J I I I \ J I _! I I I I_ I r I C_..J I (7) There ~s no ~ce now exposed along the lake shore or around the lake outlet, at the head of the Chakachatna R~ver, as was the case as recently as a few decades ago (G~les, 1969). These areas are rather un~formly vegetated and the debr~s mantle over the ~ce appears to be relat~vely th1ck compared to areas where accelerated melt~ng ~s tak~ng place These areas appear to be reasonable models of what to expect when melt~ng of the ~ce and the assoc~ated sort~ng and readJustment of the overly~ng debr~s have produced a debr~s cover th~ck enough to ~nsulate the ~ce ( 8) If the debr~s-mantled ~ce lobe 1s funct~onally decoupled from the act~ve ~ce, as suggested above, the move of ~ce toward the r~ver ~s l~kely to gradually slow ~n the near future The G~lesv (1967) data suggest that th~s slow1ng may be underway, the 1971 flood on the Chakachatna suggests that the 1ce movement ~s st~ll occas1onally rap~d enough to constr~ct the r~ver channel, however Nonetheless, 1t appears l1kely that, barr~ng a dramat1c or catastroph1c event, the degrad1ng port~on of the ~ce lobe along the r~ver w~ll slowly stab1l~ze to a cond~t~on s1m~lar to that along the lake shore Th~s w~ll probably lead to a channel conf1gurat~on somewhat w~der than at present but the channel floor elevat~on ~s unl1kely to change s1gn~f~cantly. Th~s scenar~o assumes that the d~scharge w1ll rema1n relat~vely s1m1lar to that today If d~scharge ~ncreases, then a channel deepen~ng, as suggested by G~les (1967), may occur If d~scharge decreases, the ava~lable data suggest that the outlet channel ~s l~kely to become more 5-29 5 2 1.4 narrow and perhaps more shallow as the debr1s-covered 1ce cont1nues to stab1l1ze (see Sect1on 7 0) (9) Over the long term the poss1ble changes along the uppermost reaches of the Chakachatna R1ver, where the lake level 1s controlled, are potent1ally more var1ed and more d1ff1cult to pred1ct One reason for th1s 1s that the longer t1me frame (1 e , centur1es vs decades) prov1des an 1ncreased probab1l1ty for both dramat1c (e g , marked warm1ng or cool1ng of the cl1mate) and catastroph1c (e g , large volcan1c erupt1on) events In th1s regard, 1t I I should be noted that Barr1er Glac1er and the lake outlet appear to be w1th1n the zone of greatest potent1al 1mpact from erupt1ons of Mt Spurr volcano (see Sect1on 5 2 2) Post and Mayo (1971) l1sted Chakachamna Lake as one of Alaska's glac1er-dammed lakes that can produce outburst , 1 floods They raced the flood hazard from the lake as "very low" unless the glac1er advances strongly The 1971 flood on the Chakachatna (Lamke, 1972) was attr1buted to lateral eros1on of the glac1er term1nus at the lake outlet Th1s flood may have, 1n fact, been tr1ggered by waters from an outburst flood at Pothole Glac1er, a surg1ng glac1er (Post, 1969) 1n the Nag1shlam1na R1ver Valley (Sect1on 5 2 1 5) Blockade Glac1er Blockade Glac1er (F1gure 5-l) or1g1nates 1n a very large snow and 1ce f1eld (essent1ally a mounta1n 1ce cap), h1gh 5-30 I I ( I ~-~ l I I l J 11 I I ~I I I I ' I I : J 'I r 1 L_l I I I I I I I I 1n the Ch1gm1t Mounta1ns south of Chakachamna Lake. Thls same 1ce cap area 1s also the source of several of the glac1ers that flow to the south shore of Chakachamna Lake (e g , Shamrock, Dana, and Sug1ura Glac~ers, F1gure 5-l) Blockade Glac1er flows southward out of the h1gh mounta1ns 1nto a long l1near valley, wh1ch trends NE&SW and wh1ch 1s apparently fault controlled (SectLon 5 3) Once 1n the l1near valley, Blockade Glac1er flows both to the northeast and to the southwest The southwestern branch term1nates 1n Blockade Lake, wh1ch 1s one of Alaska's glac1er-dammed lakes that 1s a source of outburst floods (Post and Mayo, 1971) The northeastern branch of the glac1er term1nates near the mouth o£ the McArthur R1ver Canyon and melt water from the glac1er dra1ns to the McArthur R1ver Blockade Glac1er 1s of spec1f1c 1nterest to the Chakachamna feas1b1l1ty study because one of 1ts branches does term1nate so near the mouth of the McArthur R1ver Canyon, and a l1kely s1te for the powerhouse for the hydroelectr1c pro]ect 1s 1n the lower port1ons of the canyon (Sect1on 3 0) Chang1ng cond1t1ons at the northeastern term1nus of Blockade Glac1er could conce1vably change the dra1nage of the McArthur R1ver to a degree that may 1nfluence cond1t1ons 1n the canyon, 1 e , at the proposed powerhouse s1tes 1n the canyon Blockade Glac1er has not been the subJect of prev1ous deta1led stud1es such as those for Barr1er Glac1er (Sect1on 5 2 1 3) Observat1ons made dur1ng the 1981 f1eld reconna1ssance covered the lower-elevat1on port1ons of the source area and both term1nal zones, but were concentrated around the northeastern term1nus, near the McArthur R1ver 5-31 At 1ts northeastern term1nus Blockade Glac1er 1s over two m1les w1de Over about half of that w1dth (the northern half) the glac1er term1nates 1n a complex of melt water lakes and ponds that are dammed between the 1ce and Neo- glac1al mora1nes The melt water from the lake system dra1ns to the McArthur R1ver v1a one large and one small r1ver that J01n and then flow 1nto the McArthur about 2 5 m1les downstream from the mouth of the McArthur R1ver Canyon A complex of recently abandoned melt water channels formerly carr1ed flow to the McArthur at the canyon mouth A small advance of the 1ce front would re1nst1tute dra1nage 1n these now dry channels Melt water 1ssu1ng from the southern half of the 1ce front flows to the McArthur R1ver 1n bra1ded streams that cross a broad outwash pla1n Whereas the northern port1on of the term1nus 1s very l1near, the southern port1on 1ncludes a d1st1nct lobe of 1ce that 1s more than a half m1le w1de and protrudes beyond the general 1ce front by more than three-quarters of a m1le Another notable character1st1c of th1s zone 1s that the Neo- glaclal mora1nes, wh1ch are so prom1nent to the north, have been completely eroded away by melt water along the southern marg1n of the glac1er On the bas1s of the above observat1ons and the report that Blockade Lake produces outburst floods (Post and Mayo, 1971), 1t appears that the d1st1nct features 1n the southern port1on of the northeast term1nal zone are present because th1s 1s the area where the outburst floods ex1t the glac1er front The broad outwash pla1n and the removal of the Neoglac1al mora1nes are probably both due to the floods, the vegetat1on-free (1 e , act1ve) outwash pla1n 1s much larger than the s1ze of the 5-32 I ~ ' I I iJ 1 ( I I L_l 1( I I I I l I I I I I I ~J ~l I I I ~ J ( I I I I I I I I I I I melt water streams would suggest The d1st1nct lobe of 1ce that protrudes beyond the general front of the glac1er probably marks the locat1on of the sub-1ce channel through wh1ch the outburst floods escape The outermost Neoglac1al rnora1nes present near the northeastern term1nus l1e about three-quarters of a rn1le beyond the 1ce front W1th the except1on of the d1st1nct 1ce lobe, the general form of the 1ce front 1s m1rrored 1n the shape of the Neoglac1al term1nal rnora1nes The outermost end mora1ne, wh1ch stands 1n the range of 20 to 40 ft above the surround1ng outwash pla1n (d1stal) and ground mora1ne (prox1mal), 1s 1n the form of a cont1nuous low r1dge w1th a gently rounded crest Three or four less d1st1nct and less cont1nuous recess1onal mora1nes are yresent between the 1ce and the Neoglac1al rnax1murn mora1nes D1st1nct glac1al flut1ng 1s present 1n the t1ll 1n th1s area The Neoglac1al end mora1ne can be traced to a d1st1nct, sharp-crested Neoglac1al lateral mora1ne that 1s essent1ally cont1nuously present along the glac1er marg1ns well up 1nto the source area for Blockade Glac1er The prox1rnal s1de of the lateral mora1ne 1s steep and vegetat1on-free, suggest1ng 1ce recess1on 1n the very recent pa~t The crest of the lateral mora1ne stands about 40 or 50 ft (est1mate based on observat1ons from the hel1copter) above the 1ce along the lower port1o~s of the glac1er A readvance of Blockade Glac1er's northeastern term1nus on the order of one-quarter to one-half a m1le would reestabl1sh dra1nage through the abandonea channels near the mouth of the McArthur R1ver Canyon such a change 1s 5-33 unl1kely to s1gn1f1cantly 1mpact cond1t1ons w1th1n the canyon but would d1srupt fac1l1t1es (e g , roads) on the south s1de of the McArthur R1ver, 1mmed1ately outs1de the mouth of the canyon The glac1er w1ll have to advance about three-quarters of a m1le before cond1t1ons 1n the canyon are l1kely to be ser1ously affected An advance of a m1le and a half would essent1ally dam the mouth of the canyon and would flood a maJor port1on of the lower reaches of the canyon, 1nclud1ng the s1tes under con- s1derat1on for the powerhouse Such a glac1er-dammed lake would l1kely produce outburst floods There 1s no ev1dence that any of the Neoglac1al advances of Blockade Glac1er were extens1ve enough to dam the McArthur R1ver Canyon The outmost of the Neoglac1al mora1nes l1es at least one-quarter of a m1le short of the po1nt where 1ce-damm1ng of the canyon would beg1n, how- ever Outwash fans on the d1stal s1de of the mora1ne may have produced m1nor pond1ng 1n the lowermost reaches observed 1n the f1eld and on the color 1nfrared a1r photos sugges~ that the last t1me that Blockade Glac1er may have dammed the McArthur Canyon was 1n late Naptowne t1me, approx1mately 10,000 years or more ago The only reasonable mechan1sm that could produce an advance of Blockade Glac1er that would be rap1d enough to 1mpact on the proposed hydroelectr1c proJect 1s a glac1er surge, a surg1ng glac1er could eas1ly advance a m1le or more w1th1n a per1od of a few decades Ev1dence for surges 1n the recent past m1ght 1nclude an advanc1ng glac1er front 1n an area where glac1ers are generally 1n recess1on and/or d1storted med1al mora1nes or long- 1tud1nal d1rt bands on the glac1er surface (Post, 1969; Post and Mayo, 1971) It 1s clear that Blockade 5-34 I I I I I I < I I ~ l l I I ~ l l ~I I 11 I I i I __j I 1 I I I I Glac1er 1 s recent h1story has been one of recess1on, as 1s the case for all other glac1ers exam1ned dur1ng the 1981 f1eld reconna1ssance There are many d1st1nct long1tUd1- nal d1rt bands and small med1al mora1nes v1s1ble on the surface of Blockade Glac1er If one or more of the 1nd1- v1dua1 1ce streams that compr1se Blockade Glac1er had recently surged, such act1v1ty should be reflected 1n contort1ons 1n the d1rt bands and med1al mora1nes V1s1ble deformat1on of the surface features on the glac1er 1s very subtle and not suggest1ve of recent surg1ng of even 1nd1v1dual 1ce streams 1n the glac1er Thus, there 1s no ev1dence of a general surge of Blockade Glac1er 1n the recent past In summary, 1t appears that Blockade Glac1er began to w1thdraw from 1ts Neoglac1al max1mum w1th1n the last few hundred years At that max1mum stand, melt water dra1n- age J01ned the McArthur R1ver at the canyon mouth and outwash may have produced some pond1ng and sed1ment aggradat1on 1n the lower reaches of he canyon, but the glac1er was not extens1ve enough to have dammed the canyon surg1ng 1s the most reasonable mechan1sm that could produce a future advance large enough and rap1d enough to 1mpact on the proposed powerhouse s1tes 1n the McArthur Canyon No ev1dence suggest1ve of surg1ng of Blockade Glac1er was 1dent1f1ed dur1ng th1s study Currently, melt water 1s carr1ed away from the canyon mouth Even markedly accelerated melt water product1on from Blockade Glac1er 1s unl1kely to change th1s cond1t1on or to have a negat1ve 1mpact on the proposed hydroelectr1c proJect 5-35 5 2 l 5 Other Glac1erb In order to get a reabonably broad-based sense of the glac1al record and h1story of recent glac1er behav1or 1n the Cakachamna Lake reg1on, the f1eld reconna1ssance 1ncluded aer1al and ground-based observat1ons of a number of the glac1ers 1n the rey1on 1n add1t1on to Barr1er and Blockade Glac1ers Those glac1ers 1ncluded (1) Shamrock Glac1er, Dana Glac1er, sug1ura Glac1er, and F1rst Po1nt Glac1er along the south shore of Chakachamna Lake (see f1gure 5-l for locat1ons), (2) Harpoon Glac1er and Pothole Glac1er 1n the Nay1shlam1na R1ver Valley, (3) Al1ce Glac1er, Crater Peak Glac1er, and Brogan Glac1er on the slopes of Mt Spurr, above tne Chakachatna R1ver, (4) Capps Glac1er ana Tr1umv1rate Glac1er on the eastern slopes of Mt Spurr, and (5) McArthur Glac1er 1n the McArthur R1ver valley Post (1969) surveyed glac1ers throughout western North Amer1ca 1n an effort to 1dent1fy 5urg1ng glac1ers Four of h1s total of 204 surg1ng glac1ers for all of western North Amer1ca are 1n tbe Chakachamna study area (F1gure 5-l) Three, 1nclud1ng Pothole Glac1er and Harpoon Glac1er, are located 1n the Nag1bhlam1na R1ver Valley, tr1butary to Chakachamna Lake, and one, Capps Glac1er, 1s on the eastern slope of Mt Spurr surface Ieatures 5-36 t r I I l I r ~ I ll I I I [__} ( 1 I I l J I I I I I I ' I ~ I I l ~nd~cat~ve of surg~ng are clearly v~s~ble on the color ~nfrared aer~al photo~raphs used ~n th~s study and were observed dur~ng f~eld reconna1ssance Spec~f~c ob&ervatlons pert~nent to an understand~ng of the glac1al h~story of the area ~nclude. ( 1) All of the glac~ers l~sted above appear to have only recently w1thdrawn from prom1nent Neoglac~al mora~nes, wh~ch ~n most (~f not all) cases mark the Neoglac~al max~mum advance pos~t~ons of the glac~ers These mora1nes and younyer recess1onal depos~ts are generally ~ce-cored for those glac~ers ~n groups 1 through 3 (above), but have l~ttle or no ~ce core ~n groups 4 and 5, wh~ch term~nate at sl~ghtly lower elevat1ons (2) Pond~ng and sudden dra1n~ng of the ~mpoundment upstream of the Pothole Glac~el (a surg~ng glac1er) end mora~ne complex ~n the Nag1shlam~na R~ver valley may ue an ep~sou~c phenomena that can produce flood~ng 1n the lower port1ons of that valley and thus a pronounced ~nflux of water 1nto Chakachamna Lake Publ~shed topograph~c maps (comp~led ~n 1962) show a small lake u~stream of the end mora1ne, wh1ch w~th the except~on of a narrow channel along the western valley wall, completely blocks the Nag~shlam~na R~ver Valley That lake ~s no longer present but there ~b clear ev~dence fo1 ~t& presence and the presence of an even larger lake ~n the recent past Features on the floor of the lower Nag~shlam~na R~ver Valley suggest recent passage of a large flood such a sudden 1nflux of water ~nto 5-37 Chakachamna Lake could produce s1gn1f1cant changes at the outlet from the lake It may be that the 1971 flood on the Chakachatna R1ver (U S G S , 1972) was tr1ggered by such an event, the stage hav1ng been set by the slow 1ncrease 1n the level of Chakachamna Lake 1n the years pr1or to the flood (Glles, 1967) (3) Only glac1ers south and east, and 1n the 1mmed1ate V1c1n1ty at Crater Peak on Mt Spurr reta1n any ev1dence of a s1gn1f1cant cover of volcan1c eJecta from the 1953 erupt1on of Crater Peak On both Crater Peak Glac1er and Brogan Glac1er (see F1gure 5-l) the 1ce 1n the term1nal zone 1s bur1ed by a th1ck cover of coarse eJecta The volcan1c mantle, where present, appears to be generally th1ck enough to 1nsulate the underly1ng 1ce The eJecta cover on Al1ce Glac1er 1s surpr1s1ngly l1m1ted Areas where the volcan1c cover formerly ex1sted, but was th1n enough so that 1ts presence accelerated melt1ng, have probably largely beeu swept clean by the melt- water In any case, the only areas where there 1s now ev1dence that the dark volcan1c mantle has or 1s produc1ng more rap1d melt1ng 1s on the marg1ns of the th1ckly covered zones on the two c1ted glac1ers (4) H1ghly contorted med1al mora1nes on Capps Glac1er, Pothole Glac1er, and Harpoon Glac1er suggest that several of the 1nd1v1dual 1ce streams that compr1se those glac1ers have surged 1n the recent past No comparable features were observed on any of the other glac1ers 1n the Chakachamna study area 5-38 I I I I I~ ~--1 I I I I I I /-1 I I I i I I I I I I I 1 I I I 5.2 1 6 Impl1cat1ons w1th Respect to the Proposed Hydroelectr1c Pro]ect Impl1cat1ons der1ved from the assessment of the glaciers 1n the Chakachamna Lake area, w1th respect to spec1fic proJect development alternat1ves, are Included In Sect1on 7 2 wh1le proJect r1sk evaluation IS disucssed In Section 7 4 General Imp1Icat1ons, not d1rectly t1ed to any spec1fic des1gn alternative, may be summar1zed as follows ( 1) ( 2) ( 3) In the absence of the proposed hydroelectric proJect, the term1nus of Barr1er Glac1er IS likely to contlnue to ex1st In a state of dynam1c equ11Ib- rium w1th the Chakachatna River and to produce small-scale changes 1n lake level through time, the term1nal fluctuations are l1kely to slow and decrease 1n s1ze In the future, lead1ng to a more stable cond1tion at the lake outlet. If development of the hydroelectric proJect or natural phenomena dam the Chakachatna R1ver Valley and flood the term1nus of Barr1er Glacier, the rate of d1s1ntegration 1s likely to Increase If the level of the lake IS raised, the rate of calving on Shamrock Glac1er 1s l1kely to Increase If hydroelectr1c development lowers the lake level, the debr1s-covered ICe of Barrier Glac1er 1s l1kely to encroach on and decrease the size of the r1ver channel, a subsequent rise 1n lake level could y1eld cond1t1ons conduc1ve to an outburst flood from the lake A lower1ng of the level of Chakachamna Lake Wlll also cause the stream channels that carry water from Ken1buna Lake and Shamrock Lake 1nto 5-39 5 2 2 5 2 2 1 Chakachamna Lake to 1nc1se the1r channels, thereby lower1ng the levels of those upstream lakes over t1me (4) There 1s no ev1dence to suggest that Blockade Glac1er w1ll have an adverse 1mpact on the proposed hydroelectr1c proJect or that the proJect w1ll have any effect on Blockade Glac1er (5) Glac1er damm1ng of the Nag1shlam1na R1ver Valley may result 1n outburst floods that 1nfluence cond1t1ons at the outlet from Chakachamna Lake (6) W1th the except1on of Shamrock Glac1er, the term1nus of wh1ch may be affected by the lake level, there 1s no ev1dence to suggest that the proposed proJect w1ll 1nfluence the glac1ers (other than Barr1er Glac1er) 1n the Chakachatna-Chakachamna Valley Changes 1n the mass balance of the Glac1ers w1ll 1nfluence the hydrolog1c balance of the lake-r1ver system, however Mt Spurr Volcano / Alaska Pen1nsula-Aleut1an Island Volcan1c Arc Mt Spurr 1s an act1ve volcano that r1ses to an elevat1on above 11,000 ft at the eastern end of Chakachamna Lake Mt Spurr 1s generally reported to be the northernmost of a cha1n of at least 80 volcanoes that extends for a d1stance of about 1,500 m1les through the Aleut1an Islands and along the Alaska Pen1nsula, recent work has 1dent1f1ed another volcano about 20 m1les north of Mt Spurr (M1ller, personal commun1cat1on, 1981) L1ke Mt 5-40 I I I I I I l I : I I I I I J I \ r 1 I I l I I I I 1-l I I t _I I I I r I~ Spurr, about half of the known volcanoes ~n the Aleut~an Islands-Alaska Pen~nsula group have been h~stor~cally act~ve The volcanoes of th~s group are al~gned ~n a long arc that follows a zone of structural upl~ft (Hunt, 1967), and that l~es ~mmed~ately north of the subduct~on zone at the northern edge of the Pac~f~c Plate The volcanoe& on the Alaska Pen~nsula developed on a basement complex of Tert~ary ana pre-Tert~ary ~gneous, sed~mentary, and metased~mentary rocks The pre-volcan~c rocks are poorly exposed ~n the Aleut~ctn Islands At the northern end of the cha~n, such as at Mt Spurr, the volcanoes developed on top of a pre-ex~st~ng to~ograph~c h~gh Mt Spurr ~s the h~ghest of the volcanoes ~n the group and the summ~t elevat~ons generally decrease to the south and west The Alaska Pen~nsula-Aleut~an Islands volcan~c cha~n ~s, ~n many ways, s~m~lar to the group of volcanoes ~n the Cascade mounta~ns of northern Cal~forn~a, Oregon, wash~ngton, and southern Br~~~sh Columb~a In general, both groups of volcanoes developed ~n already mounta~nous areas, both conb~bt of volcanoes that developed dur~ng the Quaternary and ~nclude h~stor~cally act~ve volcanoes In both areas the volcan~c rochs encompass d range of compos~t~ons but are dom~nantly andes~t~c, and both groupb conta~n a var~ety of volcan~c forms The Alaskan volcanoes ~nclude low, broad sh~eld volcanoes, steep volcan~c cones, calderas, and volcan~c domes Much of the present volcan~c morphology developed ~n late-and post-glac~al t~me 5-41 5 2 2 2 Mt Spurr Capps (1935, p 69-70) reported, "The mass of wh1ch the h1ghest peak 1s called Mt Spurr cons1sts of a great outer crater, now breached by the valleys of several glac1ers that flow rad1ally from 1t, and a central core w1th1n the older crater, the h1ghest peak of the mounta1n, from vents near the top of wh1ch steam some- t1mes st1ll 1ssues One small subs1d1ary crater, now occup1ed by a small glac1er, was recogn1zed on the south r1m of the old, outer crater " Subsequent work has shown that Capps' observat1ons were, 1n part, 1n error The error 1s spec1f1cally related to the suggest1on that the peaks and r1dges that surround the summ~t of Mt Spurr mark the r1m of a large, old volcan1c crater Why Capps had th1s 1mpress1on 1s clear because as one approaches the mounta1n from the east or southeast, the v1ew strongly suggests a very large crater, such a v1ew has suggested to many geolog1sts that Capps was correcc 1n h1s observat1ons It 1s only when one gets up on the mounta1n, an opportun1ty made pract1cal by the hel1copter, that 1t becomes clear that most of the "crater r1m" cons1sts of gran1t1c and not I I I I I volcan1c rocks The most recent and comprehens1ve report 1 1 on the d1str1but1on of l1tholog1es present on Mt Spurr 1s found 1n Magoon and others (1976) The U S Geolog1cal Survey plans to 1ssue an open f1le report on Mt Spurr 1n 1982 (M1ller, personal commun1cat1on, 1981) F1eld work a1med at assess1ng the potent1al 1mpact of volcan1c act1v1ty from Mt Spurr on the proposed hydro- electr1c development at Chakachamna Lake was concentrated 1n the area bounded by the Nag1shlam1na R1ver on the 5-42 I I \ I I I I I I I I I -1 I I I I I 1-1 west, the Chakachatna R1ver on the south, a north-south l1ne east of the mounta1n front on the east, and the Harpoon Glac1er-Capps Glac1er al1gnment on the north (F1gure 5-l) Most of the observat1ons at the h1gher elevat1ons were from the hel1copter, land1ng locat1ons h1gh on Mt Spurr are few and far between and many of the steep slopes are 1naccess1ble to other than a1rborne observat1ons It was poss1ble to make numerous surface observat1ons 1n the Nag1shlam1na R1ver and Chakachatna R1ver valleys and on the slopes below 3,000 ft elevat1on to the south and southeast of the summ1t of Mt Spurr Observat1ons made dur1ng the 1981 reconna1ssance 1nd1cate that the Quaternary volcan1cs of Mt Spurr, w1th the except1on of a1rfall depos1ts, are largely conf1ned to a broad wedge-shaped area bounded generally by Barr1er Glac1er, Brogan Glac1er, and the Chakachatna R1ver (F1gures 5-l, 5-2a and 5-2b), the d1str1but1on of Quaternary volcan1cs north of the summ1t, 1n areas that do not dra1n to the Chakachamna-Chakachatna bas1n, was not 1nvest1gated The bedrock along the western rnarg1n of Barr1er Glac1er 1s dom1nantly gran1te The only except1on observed dur1ng the f1eld reconna1ssance, wh1ch focused at elevat1ons below about 5,000 ft, was an area where the gran1te 1s capped by lava flows (F1gure 5-2a) East of Barr1er Glac1er the slopes above about 2,000 ft cons1st of 1nterstrat1f1ed lava flows and pyroclast1cs, wh1ch are exposed 1n cross sect1on The slopes of Mt Spurr 1n th1s area are not the product of tr1g1nal volcan1c depos1t1on but are eros1onal features Thus, 1t 1s clear that the volcan1cs once extended farther to the south and southwest 1nto what 1s now the Chakachamna Lake bas1n and 5-43 Chakachatna R1ver Valley The lower slopes 1mmed1ately east of Barr1er Glac1er and south of Mt Spurr cons1st of a broad alluv1al fan complex Between Al1ce Glac1er and the mounta1n front, the upper slopes of Mt Spurr, where not bur1ed by glac1er 1ce or Neoglac1al depos1ts, expose 1nterbedded lava flows (often w1th columnar J01nt1ng), pyroclast1c un1ts, and volcan1c- I I I last1c sed1ments As 1s the case near Barr1er Glac1er, I 1 most of the slopes 1n th1s area are steep, often near vert1cal eros1onal features that expose the volcan1c sequence 1n cross-sect1on The pr1mary except1on to th1s 1s found on and adJacent to Crater Peak where some of the slopes are or1g1nal depos1t1onal features Crater Peak was the s1te of the most recent erupt1on of Mt Spurr That erupt1on, wh1ch took place 1n July, 1953, was descr1bed by Juhle and Coulter (1955) The 1953 erupt1on produced an ash cloud that was observed as far east as Valdez, 100 m1les from the volcano, the d1str1but1on of eJecta on Mt Spurr demonstrates that v1rtually all of the a1rborne mater1al traveled eastward w1th the preva1l1ng w1nds The th1ck debr1s cover on Crater Peak and Brogan Glac1ers (F1gure 5-2b) 1s largely the product of th1s erupt1on Any lava that 1ssued from Crater Peak 1n 1953 was l1m1ted to the slopes of the steep-s1ded cone The erupt1on d1d produce a debr1s flow, wh1ch began at the south s1de of the crater where volcan1c debr1s m1xed w1th water from the glac1er that reportedly occup1ed the crater (Capps, 1935) and the outer slopes of the cone began to move downslope toward the Chakachatna R1ver The debr1s flow, wh1ch was probably more a flood than a debr1s flow 5-44 I I I I I I I I I I I I ----, 1 I I I I I I I I I \J -1 ~ I 'i I 1n1t1ally, eroded a deep canyon along the eastern marg1n of Al1ce Glac1er, through the Neoglac1al mora1ne complex at the term1nus of Al1ce Glac1er, and through older volcan1cs and alluv1um adJacent to the Chakachatna R1ver When 1t reachea the Chakachatna R1ver, the debr1s flow dammea the r1ver and produced a small lake that e~tended upstredm to the v1c1n1ty of Barr1er Glac1er The dam was subsequently part1ally breached, lower1ng the 1mpoundment 1n the Chakachatna Valley to 1ts present level EV1dence for the h1gh water level 1ncludes tr1butary fan-deltas graaed to a level above the current wa~er level and a "bath tub r1ng" of sed1ment and l1ttle or no vegetat1on along the southern valley wall East of the 1953 debr1s flow, the Chakachatna R1ver flows through a narrow canyon w1th1n the broader valley bounded by the upper slopes of Mt Spurr on the north and the gran1t1c Ch1gm1t Mounta1ns on the south The southern wall of the canyon (and valley, as whole) cons1sts of glac1ally-scoureu gran1t1c bedrock W1th the except1on of remnant depos1ts of the 1953 debr1s flow that are present aga1nst the gran1t1c bedrock (F1gure 5-2b), the 1981 reconna1ssance y1elded no ev1dence of volcan1c or volcan1clast1c rocks on the southern wall of the Cnakachatna Valley The northern wall of the Chakachatna Canyon exposes a complex of h1ghly weathered (altered ?) andes1t1c lava flows, pyroclast1cs, volcan1clast1c sed1ments, outwash, and 1n one locat1on, what appears to be an old (pre-Naptowne) t1ll. Although the general late-Quaternary h1story of the Chakachatna R1ver Valley 1s reasonably clear, the deta1ls of that h1story are very complex and would requ1re an 5-45 extens~ve f~eld program to unravel The observat~ons made dur~ng the 1981 reconna~ssance suggest the follow~ng. (1) Late-Tert~ary and/or early-Quaternary volcan~c act~v~ty at Mt Spurr bu~lt a th~ck p~le of lava flows, pyroclast~cs, and volcan~clast~c sed~ments on top of a gran~t~c mounta~n mass of some cons~derable rel~ef (2) Interspersed volcan~c and glac~al act~v~ty occurred dur~ng the Ple~stocene, w~th alternat~ng per~ods of eros~on and depos1t1on. The w1dth of the valley at Chakachamna Lake 1s ma1nta1ned downstream to the area of Al1ce Glac1er (F1gure 5-2a) From that po1nt to the mounta~n front, where the same broad valley form seems to reappear, the overall valley 1s plugged by a complex of volcan1c (and glac1al) depos1ts Th1s, along w1th the volcan1c cl1ffs h1gh on the slopes of Mt Spurr, suggests that volcan1cs once largely f1lled what 1s now the Chakachatna Valley, that glac1ers then eroded a broad, u-shaped valley (such as ~s st1ll present 1n the lake bas1n), and that subsequent volcan~c act~v1ty produced the bulk of the depos1ts that form the valley "plug". (3) The age of the volcan1cs 1n the "plug" 1s not clear Some of the characterlStlCS of the basal volcan1c rocks exposed along the r1ver suggest some ant~qu1ty. For example, many lava flows are so deeply weathered (or altered ?) that the rocks d1s1ntegrate 1n one's hand These volcan1cs appear to be overla1n by outwash and may be 1nterbedded w1th t1ll, wh1ch 1s also deeply weathered 5-46 ~ I I I I I I I I 1-1 I I I I I I I 1~1 I I I I I r 1 I (~ I I ( I I I - I I I ~ I I I I I I~ I I \ I I ( I I I (altered?) These and other features suggest that at least some of the volcan1cs 1n th1s area were depos1ted 1n pre-Naptowne t1me Glac1al depos1ts, 1nclud1ng mora1nes, a large area of kame and kettle depos1ts,and glac1er-marg1nal lake depos1ts 1nterpreted to be a late-Naptowne age overl1e port1ons of the volcan1c valley plug [See Sect1on 7 2 for d1scuss1on of 1mpl1cat1ons w1th respect to a dam 1n the Chakachatna Canyon ] In contrast, 1t 1s d1ff1cult to understand how the apparently eas1ly eroded volcan1cs 1n th1s area surv1ved the Naptowne-age glac1ers that f1lled the Chakachatna Valley and were large enough to extend across Cook Inlet (Karlstrom, 1964) In add1t1on, there are many landforms, such as volcan1c p1nnacles, that clearly are post glac1al as they could not have surv1ved be1ng overr1den by glac1er 1ce such landforms demand the removal of several tens of feet of volcan1cs over large areas. Although the ev1dence 1s confl1ct1ng and an unamblg- uous 1nterpretat1on d1ff1cult, 1t does appear that much of the volcan1c valley plug 1s of pre-Naptowne age The bas1s for th1s conclus1on 1s most clearly documented by the presence of outwash on top of volcan1cs, a sequence exposed at several s1tes 1n the canyon The outwash 1s capped by a three-to-four foot th1ck cap of volcan1c ash (many d1screte depos1t1onal un1ts) as 1s typ1cal of Naptowne-age surfaces 1n the area Just how these volcan1cs surv1ved the Naptowne glac1at1on 1s not clear 5-47 (4) Follow1ng the w1thdrawal of the Naptowne 1ce from the Chakachatna R1ver Valley, Holocene volcan1c act1v1ty, glac1al act1v1ty, and fluv1al and slope processes have produced the present landscape Most, 1f not all of the present 1nner canyon, through wh1ch the Chakachatna R1ver flows, appears to be the product of Holocene downcutt1ng by the r1ver G1ven that many of the deta1ls of the Quaternary h1story of Mt Spurr are not well understood, 1t 1s nonetheless clear that Mt Spurr 1s an act1ve volcano that may produce lava flows, pyroclast1cs, and volcan1clast1c sed1ments 1n the 1mmed1ate v1c1n1ty w1th1n the l1fe of the proJect A1rfall depos1ts can be expected to 1nfluence a larger area Cons1der1ng the s1ze and type of volcan1c events for wh1ch there 1s ev1dence at Mt Spurr and the present topography, the area of 1nterest to the proposed hydroelectr1c proJect most l1kely to be affected 1s the area between Barr1er Glac1er and the 1953 debr1s flow The topography of the valley plug volcan1cs appears to afford some, but certa1nly not total protect1on to the canyon port1on of the r1ver valley, an example of th1s "protect1on" 1s prov1ded by a second debr1s flow produced 1n 1953 that was prevented from reach1ng the r1ver by 1nterven1ng topography on the valley "plug" The types of volcan1c event JUdged to be most l1kely to 1mpact the Chakachatna R1ver Valley 1n the near future are 5-48 I I 1 I I '~ _I I I I I I I I I I I I (1) 1953-type debr1s flows wh1ch could 1nundate a \ I port1on of the valley and re-dam the r1ver, I I i I r ~ I _I I ~, ! I I I I I [l I I !~ ) ~ I I I I (' I I I I 5 2 2 3 (2) lava flows, wh1ch could enter and dam the valley, and (3) large floods that would be produced by the melt1ng of glac1er 1ce dur1ng an erupt1on Post and Mayo (1971) suggested that melt1ng of glac1er 1ce on Mt Spurr dur1ng volcan1c act1v1ty may present a ser1ous hazard S1gn1f1cant d1rect 1mpact on Barr1er Glac1er would demand a summ1t erupt1on that 1ncluded the £low of hot volcan1cs at least 1nto the upper reaches of the glac1er or the development of a new erupt1ve center (such as Crater Peak) west of the present summ1t Of course the character of the volcanoes 1n the Aleut1an Island-Alaska Pen1nsula cha1n make 1t clear that a very large event (1 e , a Mt St Helens--or even a Crater Lake-type event) 1s poss1ble at Mt Spurr, such an event has a very low annual probab1lty of occurrence at any g1ven s1te, however Impl1cat1ons w1th Respect to the Proposed Hydroelectr1c ProJect The potent1al 1mpact of Mt Spurr on the proposed hydroelectr1c proJect w111, 1n part, vary as a funct1on of the proJect des1gn (see Sect1ons 7 2 and 7.4), but some potent1al w1ll always ex1st because o£ the locat1on of Mt Spurr relat1ve to Chakachamna Lake and the Chakachatna R1ver. The amount of negat1ve 1mpact on the proJect 1s clearly a funct1on of the s1ze of volcan1c event cons1dered, larger events, wh1ch would have the greatest potent1al for adverse 1mpact, are, 1n general, 5-49 t_ less l1kely to occur than smaller volcan1c events Some general poss1b1l1t1es that m1ght be assoc1ated w1th low- to med1um-1ntens1ty events (such as a Crater Peak event or sl1ghtly larger) 1nclude (1) Damm1ng of the Chakachatna R1ver by lava or debr1s flows, w1th the most l1kely s1te be1ng 1n the v1c1n1ty of the 1953 debr1s dam. Flood1ng of the term1nus of Barr1er Glac1er may 1ncrease the rate of 1ce melt and poss1bly alter the conf1gurat1on of the current lake outlet Any proJect fac1l1t1es on the valley floor of the upper valley would be bur1ed by the flow and/or flooded (2) Flood1ng of the Chakachatna R1ver Valley as a result of the melt1ng of glac1er 1ce on Mt Spurr dur1ng an erupt1on ProJect fac1l1t1es near or on the valley floor would be flooded (3) Accelerat1ng the retreat of Barr1er Glac1er due to the flow of hot volcan1c debr1s onto the glac1er In the extreme, Barr1er Glac1er could be el1m1nated 1f enough hot mater1al flowed onto the 1ce A less dramat1c scenar1o could 1nclude destab1l1zat1on of the lake outlet due to accelerated melt1ng 1n the term1nal zone of Barr1er Glac1er In contrast, a large lava flow at the present s1te of Barr1er Glac1er could replace the glac1er as the eastern marg1n of the lake, prov1d1ng a more stable darn than that prov1ded by Barr1er Glac1er Each of the des1gn alternat1ves (Sect1on 3 0) 1ncludes a lake tap 1n the zone between the lake outlet and F1rst Although 1t 1s generally true that a s1te 5-50 I I I ) i ,-I I I I~ I I I J I I I I I : ~ I I I / I ) I I I I ,I I I I I I I : I I I r 1 I : I I I I_ J J i / I I I I 5 2 3 5 2 3 1 farther from Mt Spurr ~s less l~kely to be subJect to volcan~c hazards than a s~te closer to the volcano, there ~s no apparent reason to favor one part~cular s~te ~n the proposed zone over any other s~te ~n that zone A large erupt~ve event, apparently substant~ally larger than any of the Holocene events on Mt Spurr, would be requ~red before the proposed lake tap s~te would be d~rectly threatened by an erupt~on of Mt Spurr Slope Cond~t~ons The Ch~gm~t Mounta~ns, south of Chakachamna Lake and the Chakachatna R~ver, and the Tordr~llo Mounta~ns, to the north, conta~n many steep slopes and near-vert~cal cl~ffs Th~s landscape ~s largely the product of mult~ple glac~at~on dur~ng the Quaternary, ~nclud~ng Neoglac~at~on wh~ch cont~nues ~n the area today The proposed hydroelectr~c proJect ~s l~kely to ~nclude fac~l~t~es ~n the Chakachamna Lake bas~n and e~ther or both of the McArthur and Chakachatna R~ver valleys Any above-ground fac~l~t~es ~n these areas w~ll be on or ~mmed~ately adJacent to steep slopes 1 and thus subJect to \ any slope processes that may be act~ve ~n the area Because of th~s fact, the 1981 f~eld reconna~ssance ~ncluded observat~ons of slope cond~t~ons ~n the areas of ~nterest Future f~eld work should ~nclude deta~led assessment of bedrock character~st~cs, such as JO~nt or~entat~ons, that ~nfluence slope cond~t~ons Chakachamna Lake Area Chakacharnna Lake s~ts ~n a glac~ally overdeepened bas~n that ~s generally bordered by steep slopes of gran~t~c bedrock that ,was scoured dur~ng Naptowne and earl~er 5-51 5 2 3 2 glac1at1ons Locally, such as along the southern valley wall west of Dana Glac1er (F1gure 5-2a), d1st1nct bedrock benches are present. In other areas, the slopes r1se, w1th only m1nor var1at1on 1n slope, from the lake level to the surround1ng peaks All pr1nc1pal valleys along the southern s1de of the lake presently conta1n glac1ers The pr1nc1pal valleys tr1butary to the north s1de of the lake, the Ch1ll1gan and Nag1shlam1na, are larger than those on the south s1de of the lake and are currently essent1ally 1ce-free, although the1r present form 1s clearly the product of glac1al eros1on No ev1dence of large-scale slope 1fa1lures of the slopes 1n the Chakachamna Lake bas1n was observed dur1ng the 1981 f1eld reconna1ssance Most of the slopes are glac1ally-scoured bedrock and are essent1ally free of loose rock debr1s, although talus 1s locally present The or1entat1on of ]01nt sets 1n the gran1t1c bedrock var1es somewhat from area to area. In many areas a near hor1zontal out-of-slope J01nt set 1s present, but 1t tends to be poorly expressed relat1ve to more steeply-d1pp1ng J01nts F1eld work 1nd1cates that th1s and cross-cutt1ng J01nts have formed boulder-s1ze p1eces and small slabs that produce rockfall as the only common type of slope fa1lure for wh1ch any ev1dence was found Th1s cond1t1on 1s apparently most pronounced along the southern valley wall, between sug1ura Glac1er and the lake outlet Chakachatna R1ver Valley The Chakachatna R1ver, from 1ts or1g1n at Chakachamna Lake to the mounta1n front, flows through a valley that 1s rather var1able 1n 1ts form and character1st1cs along 5-52 I I ~ ~ I I j l 1 I I h II I I I I l ( I I j I I I I ( ) I I ,I I I I ~ ( " I I I 1 J I I I lj \ r I __ \ ~ I I ! -I I I\ I I ~ I 1 1ts length and from s1de to s1de Throughout the valley, the south s1de cons1sts of steep glac1ated gran1t1c bedrock slopes that r1se essent1ally cont1nuously from the r1ver to the adJacent mounta1n peaks All maJor tr1butary valleys on the southern valley wall, many of wh1ch are hang1ng valleys, now conta1n glac1ers The comments regard1ng slope cond1t1ons on the slopes above the lake (Sect1on 5 2 3 1) apply to the southern wall of the Chakachatna R1ver Valley The north s1de of the valley d1ffers from the south s1de 1n v1rtually every conce1vable way On th1s s1de bedrock 1s volcan1c, and glac1al and fluv1al sed1ments are also present In the westernmost port1on of the valley, the r1ver 1s bordered by the Barr1er Glac1er mora1ne and alluv1al fans, steep volcan1c blopes above the alluv1al fans are subJect to rockfall act1v1ty Between Al1ce Glac1er (the area of the 1953 debr1s flow) and the valley mouth, the r1ver flows through a narrow canyon, the north s1de of wh1ch cons1sts of a var1ety of 1nterbedded volcan1cs, glac1al depos1ts, and fluv1al sed1ments (F1gure 5-2b) The north canyon wall has been the s1te of several landsl1des that range 1n s1ze from small slumps to large rotat1onal sl1des such act1v1ty 1s l1kely to cont1nue 1n the future Its 1mpact w1ll most frequently be l1m1ted to the d1vers1on of the ma1n r1ver course away from the north canyon wall, there are several examples of th1s now ~resent 1n the canyon A large landsl1de, wh1ch appears to be unl1kely g1ven the he1ght of the slopes, could completely dam the canyon, part1al damm1ng w1th temporary pond1ng appears to be a more l1kely pOSSlblllty 5-53 5 2 3.3 Volcan1c act1v1ty on Mt Spurr could d1rectly 1nfluence cond1t1ons along the Chakachatna R1ver (Sect1on 5 2.2)y or could, by slowly alter1ng cond1t1ons along the north I I I wall of the canyon, have a secondary 1mpact on the valley 1 ' McArthur R1ver Canyon The McArthur R1ver Canyon 1s a narrow, steep-walled glac1ated valley A poss1ble powerhouse s1te has been 1dent1f1ed along the north wall of the canyon (Sect1on 3 0) and the follow1ng comments spec1f1cally refer to the north wall of the McArthur R1ver Canyon The valley walls, wh1ch cons1st of gran1t1c bedrock, expose a The complex of cross-cutt1ng JOLnt sets and shear zones character and dom1nant or1entat1ons of the J01nts and shears vary along the length of the canyon and the character of the slopes also var1es, apparently 1n d1rect response Except near the canyon mouth, there 1s no ev1dence of large-scale slope fa1lure and rockfall 1s the dom1nant slope process Between the term1nus of McArthur Glac1er and M1sty Valley (F1gure 5-l) the J01nt sets are of a character and or1entat1on such that rockfall has been act1ve and the bedrock on the lower slopes on the north valley wall are un1formly bur1ed beneath a th1ck talus The vegetat1on on the talus suggests that the bulk of talus development took place some t1me soon after de- glac1at1on and rockfall has been less act1ve recently The slopes between M1sty and Gash Valleys (FLgure 5-l) cons1st of glac1ally-scoured bedrock that 1s essent1ally talus free, suggest1ng l1ttle or no rockfall 1n th1s area 5-54 I 1 I I I , I I I I I I ~ I I I D I I f I I I ,~ I I ( I I I I r I I \ p I 1 l I I I 5 2 3 4 From Gash Valley to the canyon mouth, the gran~t~c bedrock appears to become progress~vely more ~ntensely JO~nted and sheared and thus more subJect to rockfall and small-scale slump~ng Talus mantles the lower slopes ~n much of th~s area A large fault zone (Sect~on 5 3) ~s present at the canyon mouth. The fault has produced ~ntense shear~ng over a broad zone that ~s now subJect to ~ntense eros~on and ~s the s~te of several landsl~des Impl~cat~ons w~th Respect to the Proposed Hydroelectr~c ProJect As ~n the case for volcan~c hazards, there ~s no apparent reason w~th respect to slope cond~t~ons to favor one s~te over any other ~n the zone between the lake outlet and F~rst Po~nt Glac~er for the lake tap Rockfall appears to be the only potent~al slope hazard ~n that zone, there was no ev~dence observed ~n the f~eld to suggest other types of slope fa~lure As ~nd~cated on F~gure 5-9, the Castle Mounta~n fault (Sect~on 53), wh~ch ~sa maJor fault, crosses the McArthur R~ver JUSt outs~de the canyon mouth (Sect~on 7.4) where the gran~t~c bedrock has been badly shattered by fault movement Surface exam~nat~on reveals that the rock qual~ty progress~vely 1mproves w1th d~stance upstream from the canyon mouth and the best qual~ty rock l~es between Gash Valley and M~sty Valley (F~gure 5-l), beg~nn~ng about 1-1/2 m~les upstream from the powerhouse locat~on presently shown on the draw~ngs Th~s locat~on ~s based on econom~c cons~derat~ons alone, w~thout tak~ng account of the h~gher excavat~ons costs that would be assoc~ated w~th the poorer qual~ty rock A cr~t~cal evaluat~on of the rock cond1t1ons ~n th~s area should be 5-55 5 3 5 3 1 1ncluded 1n future stud1es and a s1te should be selected for dr1ll1ng a deep core hole A powerhouse s1te at or 1mmed1ately outs1de the canyon mouth, as has been cons1dered 1n other stud1es, 1s l1kely to be 1n the fault zone and subJect to fault rupture as well as h1gh ground mot1ons In add1t1on, fac1l1t1es outs1de the canyon w1ll be 1n Tert1ary sed1mentary rocks and glac1al depos1ts, not gran1te Se1sm1c Geology Tecton1c Sett1ng The act1ve fault1ng, se1sm1c1ty, and volcan1sm of southern Alaska are products of the reg1onal tecton1c sett1ng The pr1mary cause of the fault1ng and se1sm1c act1v1ty 1s the stress 1mposed on the reg1on by the relat1ve mot1on of the Pac1f1c l1thospher1c plate I I \ I I I relat1ve to the North Amer1can plate along the1r common \i 1 boundary (F1gure 5-3). The Pac1f1c plate 1s mov1ng northward relat1ve to the North Amer1can plate at a rate lof about 2 4 1nches/year (Woodward-Clyde Consultants, 1981 and references there1n). The relat1ve mot1on between the plates 1s expressed as three styles of deformat1on Along the Alaska Panhandle and eastern marg1ns of the Gulf of Alaska, the movement between plates 1s expressed pr1mar1ly by h1gh-angle str1ke-sl1p faults Along the northern marg1ns of the Gulf of Alaska, 1nclud1ng the Cook Inlet area, and the central and western port1ons of the Aleut1an Islands, the relat1ve mot1on between the plates 1s expressed by the underthrust1ng of the Pac1f1c plate beneath the North Amer1can plate At the eastern end of the Aleut1an 5-56 I I \ ~) ) I I J ( -, I I LJ I -j r " I I I r""' I I ( ) ~~I I I _ __, I ! I ~ I 1 l ~J ,-\ I I (_; 600 \ \ \ \ ,, ' EURAS~AN '~\ \ \ PLATE \ 150 NOTES Base map from Tarr (1974) 2 After Packer and others (1975) Be1kman (1978) Corm1er (1975) Reed and Lamphere (1974) Plafker, and others (1978) ---------------------- PACIFiC 180 PlATE PLATE 150 WOODWARD CLYDE CONSULTANTS -------------~ -----------I LEGEND Wrangell Block -* Relative Pac1f1c Plate Mot1on _...,.,...,.Plate Boundary dashed where mferred A A A Shelf Edge Structure With Obl1que Slip ---Intraplate Transform or Stnke Slip Fault No DATE REVISION BV ALASKA POWER AUTHORiTY ANCHORAGE, ALASKA CHAKACHAMNA HYDROELECTR!QJROJECT Plate Tectonic Map BECHTEL CIVIL & MINERALS, INC DEitOHED ENQA SUPV REV F1gure f?-3 I I I" ' _, I ' \ ' ) jl I t I I J \ /) t ' I I~, I I ' J Cl - I \ L I Islands, the relat~ve plate mot~on lS expressed by a complex trans1t1on zone of obl~que thrust fault1ng The Chakachamna Lake area 1s located 1n the reg~on where the 1nterplate mot~on 1s produc~ng underthrust1ng of the Pac~f1c plate beneath the North Amer1can plate Th~s underthrust1ng results pr~mar1ly 1n compress1onal deformat1on, wh1ch causes folds, hlgh-angle reverse faults, and thrust faults to develop 1n the overly1ng crust The boundary between the plates where under- thrustlng occurs ~s a northwestward-d1pp1ng megathrust fault or subduct~on zone The Aleut~an Trench, wh1ch marks the surface express1on of th~s subduct1on zone, 1s I located on the ocean floor approx1mately 270 m1les south of the Chakachamna Lake area The or~ent~at~on of the subduct1on zone, wh1ch may be subd1v1ded 1nto the mega- thrust and Ben1off zone (Woodward-Clyde Consultants, 1981), 1s 1nferred at depth to be along a broad 1ncl1ned band of se1sm~c1ty that d1ps northwest from the Aleut1an Trench The close relat1onsh1p between the subduct1on zone and the structures w1th1n the overly1ng crust 1ntroduces 1mportant 1mpl1cat1ons regard1ng the effect of the tecton1c sett1ng on the Chakachamna Lake ProJect The subduct~on zone represents a source of maJor earthquakes near the s1te Faults ~n the overly1ng crust, wh1ch may be subs1d~ary to the subduct1on zone at depth, are sources of local earthquakes and they may present a potent~al hazard for surface fault rupture Th1s 1s of spec1al concern because the Castle Mounta1n, Bru1n Bay, and several other smaller faults have been mapped near to the Chakachamna Lake Hydroelectr1c ProJect area 5-59 5 3 2 5 3 2 1 (Detterman and others, 1976, Magoon and others, 1978) Future act~v~ty on these faults may have a more profound affect on the se~sm~c des~gn of the proJect structures than the underly~ng subduct~on zone because of the~r closer prox~m~ty to proposed proJect s~te locat~ons H~stor~c Se~sm~c~ty Reg~onal Se~sm~c~ty Southern Alaska ~s one of the most se~sm~c~ally act~ve reg~ons ~n the world. A number of great earthquakes (R~chter surface wave magn~tude Ms 8 or greater) and large earthquakes (greater than MS 7) have been recorded dur~ng h~stor~c t~me. These earthquakes have pr~mar~ly occurred along the ~nterplate boundary between the Pac~f~c and North Amer~can plates, from the Alaskan panhandle to Pr~nce W1ll~am Sound and along the Kena~ and Alaska Pen~nsulas to the Aleut~an Islands. Among the recorded earthquakes are three great earthquakes that occurred ~n September 1899 near Yakutat Bay, w~th est~mated magn~tudes Ms of 8 5, 8 4, and 8 1 (Thatcher and Plafker, 1977) Ground deformat~on was extens~ve and vert~cal offsets ranged up to 47 ft (Tarr and Mart~n, 1912), these are among the largest known d~splacements attr~butable to earthquakes Large parts of the plate boundary were ruptured by these three earthquakes and by twelve others that occurred between 1897 and 1907, these ~ncluded a magn~tude Ms 8 1 event on 1 October 1900 southwest of Kod~ak Island (Tarr and Mart~n, 1912, McCann and others, 1980) and a nearby magn~tude Ms 8.3 earthquake on 2 June 1903, near 57° north lat~tude, 156° west long~tude (R~chter 1 1958) 5-60 - I I ' I r ' ~ I I , r 1 I I \_j I I r l I I \ \ J I I I I I_J ll l] 5.3 2.2 A sLmLlar serLes of maJor earthquakes occurred along the plate boundary between 1938 and 1964. Among these earthquakes were the 1958 LLtuya Bay earthquake (Ms 7 7) and the 1972 S1tka earthquake (Ms 7 6), both of whLch occurred along the FaLrweather fault system Ln southeast Alaska, and the 1964 PrLnce WLllLam Sound earthquake (Ms 8 5), whLch ruptured the plate boundary over a WLde area from Cordova to southwest of KodLak Island and whLch produced up to 39 ft of dLsplacement (HastLe and savage, 1970) FLgure 5-4 shows the aftershock zones of these and other maJor earthquakes Ln southern Alaska and the AleutLan Islands The maLn earthquakes and aftershocks are Lnferred to have ruptured the plate boundary Ln the encLrcled areas. Three zones along the plate boundary whLch have not ruptured Ln the last 80 years have been LdentLfLed as wseLsmLc gapsn (Sykes, 1971) These zones are located near Cape Yakataga, Ln the VLCLnLty of the ShumagLn Island, and near the western tLp of the AleutLan ChaLn as shown Ln FLgure 5-4 The Yakataga seLsmLC gap LS of partLcular Lnterest\to the proJect because of Lts proxLmLty to the sLte regLon. The rupture zone of a maJor earthquake fLllLng thLs gap has the potentLal to extend along the subductLon zone to the north and northwest of the coastal portLon of the gap near Yakataga Bay HLstor1c Se!Sm1c1ty of the ProJect Study Area The h1storLc seLsmLcLty WLthLn 90 mLles of the proJect area, approxLmately centered on the east end of Chakachamna Lake, LS shown Ln FLgures 5-5, 5-6, and 5-7 The earthquake locatLons are based on the Hypocenter Data 5-61 F~le prepared by NOAA (Nat~onal Ocean~c and Atmospher~c Adm~n~strat~on, 1981) The Hypocenter Data F~le ~ncludes earthquake data from the U S Geolog~cal Survey and other sources and represents a fa~rly un~form data set ~n terms of qual~ty and completeness s~nce about 1964 Based on F~gures 5-5, 5-6, and 5-7 and data ava~lable ~n the open l~terature, the se~sm~c~ty of the proJect area ~s pr~mar~ly assoc~ated w~th four pr~nc~pal sources the subduct~on zone, wh~ch ~s d~v~ded ~nto two segments--the Megathrust and Ben~off zone (Woodward-Clyde Consultants, 1981,, Lahr and Stephen, 1981), the crustal or shallow se~sm~c zone w~th~n the North Amer~can Plate, and moderate to shallow depth se~sm~c~ty assoc~ated w~th volcan~c act1v~ty The se~sm~c sources are br~efly d~scussed below ~n terms of the~r earthquake potent~al The Megathrust zone ~s a ma]or source of se~sm~c act~v~ty that results pr~mar~ly from the ~nterplate stress accumulat~on and release along a gently ~ncl~ned boundary between the Pac~f~c and North Amer~can plates Th~s zone ~s the source area of many of the large to great earth- quakes, ~nclude the Ms 8 5 1964 Pr~nce W~ll~am Sound earthquake, wh~ch ruptured along the ~ncl~ned plate boundary from the eastern Gulf of Alaska to the v~c~n~ty of Kod~ak Island The max~mum magn~tude for an earthquake event along the Megathrust zone ~s est~mated to be Ms 8 5 (Woodward-Clyde Consultants, 1980, 1981) The Ben~off zone port~on of the subduct~on zone ~s bel~eved to be restr~cted to the upper part of the descend~ng Pac~f~c plate, wh~ch l~es beneath the North Amer~can plate ~n southern Alaska Th~s zone ~s the source of smaller magn1tude and more cont~nuous 5-62 1 I I I I I ' r- 1 I ~ ~ I I -, I (_I ,~ 1 l I l ' I --,1 I I 150 110 160 120 w "', 6! N ~<J l a4 LEGEND 0 1964 Locatton and year of major earthquake rupture zones mcludmg aftershock areas are outlmed ""' .:.: Inferred d1rect10n of motton of Pactftc plate Trench axts ---m--Approximate transform plate 1 ~, margm I I , __ I I ,_, I~ I i ' 1 I I I -" - I \ I 50 ;- / 110 E 17! NOTE Modtfted after Dav1es and House ( 1979) pA CIFI J 160 165---14! 140 w WOODWARD CLYDE CONSULTANTS No DATE REVISION I I ~ l 1 1 AlASKA POWER AUTHORITY I . I j L' ANCHORAGE, ALASKA CHAKACHAMI\!A HYDROELH.TRffi_.PROJECi Major Earthquakes and Setsmtc Gaps tn Southern Alaska BECHTEL CIVIL & MINERALS, INC SAN FRANCISCO DESIO NED CHECKED ENOR SUPV APPD REV t!IIJ DRAWING No ------------------~-=-=-=-=~~~-~-~-~================~~~========~============================================:===========~------------------------------------~--------------l!~~_l~~~j_--~F~tg~u~r:e~6~4~==c=J ------------~ ~---- .,.. I I~ 1 I I I I l_j I ' l_j I I i \ i ~' --,. I I 1 I (_ I I \ \ : -J I I I l_l J ; 62 DO •MT STONEY l!l l!l l!l ~\\..E. RADIUS ?,0 .~ MT GERDINE -_l!l - C9 l!l l!l l!l l!l l!l (> l!l @l!l -@ l!l ,.Jl~ o SNOWCAP MOUNTAIN -c!f-C) (') Q) BELUGA LAKE MT SUSITM'A l!l l!l GOLDPAN PEAK • 61 DO l!l TURQUOISE LAKE 60 50 l!l l!l l!l WOODWARD CLYDE CONSULT ANTS C) C) l!l l!l l!l l!l l!l • REDOUBT VOLCANO l!l C) l!l l!lg (') (') Q) MT SPURR l!l l!l C) $ )!LOCKADE LAKE Q) l!l 1!1(9 1!1 l!l l!l 1!1 l!l 1!1 C) l!l l!l l!l l!l l!l l!l ~ fYONEK 1!1 C) 1!1(9 C9 l!l l!l FIR& ISLAND (') Q) (>p C) C) 1!1 C9 l!l 1!1 1!1 C9 C9 l!l C) (') 1!1 KENAI • Q) l!l C) 1!11!1@ s:ERLING 1!1 0 5 10 15 20 M1les e----. E3 E3 0 510152025 Kilometers 62 00 C) G 1 DO l!l NOTE LEGEND REPBRTED MRGNITUDE C9 8 0 7 0 6 0 5 0 4 0 3 0 2 0 I 0 No Reported Magmtude INTENSITY ~XII v XI vx <!> IX ~ VIII ~ 0 ~ VI I VI v Magmtude symbol s1zes are shown on a contmuous nonlmear scale \' ' .----r----,----------r---r--r---.-....--1 ~' ' r ' -(' \. ~r--r--------r-+-+-+~~ ~ l 1 ) ; 1-t----+-------+-+-+-+-f----1 I r No DATE REVISION ALASKA POWER AUTHORITY ANCHORAGE, ALASKA Histone Earthquakes of All Focal Depths m the S1te Reg1on from 1929 Through 1980 BECHTEL CIVIL & MINERALS, INC SAN FRANCISCO DESIGNED CHECKED ENGR SUPV ORAWINGN REV F1gure -6-5 ; 1 ( ~, I I I ( ; I I I L' r--1 I I I I ( l ! I I r I ( I I I I r-, I \ I I ( I \ I r I I { ~---} '~ I -ISO SO ~ISO DO -1Si4 __ DD _________ -_I_S3~S-D _________ -I~S+3-0~0~--------~IS42~S~O--------~l~S~2~0~0----------t-~---~--~-~l~S~l~O~O--------~~~----~mr---r62 06 62 06 I) U 62 DO 61 so 61 DO 60 so + + + C) o MT STONEY ~C) c SNOWCAP MOUNTAIN GOLDPAN PEAK 0 +C) [!) [!) [!) [!) i!lo C) C) C) MT SPURR [!) [!) [!) @ C) c®Q) + (9 m@ + [!JTI C) d- SKWENTNA G [!) ~ [!) C) C)[!)[!) c:JJl ~ [!)C) [!) ~ ~·cP [!) [!) C) ~[!) [!) C) C) [!) C) C) Q) [!) [!) Q) (9 (') +[!) @ M~ SUSITffA rn C)~ [!) [!) [!) [!) C) [!) [!) C) [!)(!) FIRE ISLAND [!) ~AM~A LAK;rnrn KENIBUNA LAKE rn C) C) ~P C) + [!) TURQUOISE LAKE C) C) [!) [!) [!) [!) [!) [!) [!) +[!) C) + ~OCKADE LAKE C) [!) [!) [!) [!) [!) [!) [!) [!) [!) [!) 6') REDOUBT VOLCANO rn ~ rn C) rn A~IN !SLAND [!) [!) (') Q) C) C) & (9 [!) (I] STERLING rnrn\J rn [!) [!) [!) [!) (') [!) 62 DO 61 so 61 00 60 so + C) CB [!) 9 1[!) ~ C) + C) C9 C)~ C) rn rn C) : rn m mC) c:l rnSKILAK LAKE ~~~----------~---d~--~c::J:_ __ ~----~------~-4~~~~~+-----~~~[!J-----+--~--~~~--~~~------~~~~------~~60 33 60 33 ::1: i!l -150 DO -1--154 DO -I 53 50 -153 DO -I 'i? 'i[l -I 'i? [1[1 -151 SO -151 00 -I SO SO 0 5 10 15 20 M1les F*"*3 e-+3 ,___, ,___, F3 WOODWARD CLYDE CONSULTANTS 0 5 10 15 20 25 K1lometeys NOTE LEGEND REPBRTED MAGNITUDE "' 8 0 7 0 6 0 5 0 4 0 3 0 r 8 No Reported Magmtude INTENSITY ~ Xll ~XI <Yx <Y IX <() VIII ~ ~ 0 VI I VI v 1 Magmtude symbol s1zes are shown on a contmuous nonlmear scale I I I II ~ I ! j Jt l,, -..--~---------------r~~~--~ :1 .... I r-~ ~~-+--------------~-+-+-+--~ ! '~ ~~-+--------------~-+-+-+~~~\~ f f ~~-+--------------~-+-+-+--~~ ~I No DATE REVISiON BV UP ;~g.:. ~AGO~ l ! ~!,.. AlASKA POWER .AUTHORITY I'• '~1 ANCHORAGE ALASKA CHAKACHAMNA HYDROELECT.fiLCJ!IJ)JECT Histone Earthquakes of Focal Depth Greater Than 20 Miles In the Site R e 1on from 1929 Th rou h 1980 BECHTEL CIVIL & MINERALS, INC DESIGNED CHECKED ENGA SUP\1 APf'O OAAWINGN F1gure 5-6 I II II I I <' I REV I I I I I I 1 I I I I ~ ) I I I r I I l, ~ ~, i c I I " I I r--1 ( ~I 62 08 62 DO 61 50 61 00 154 00 -153 50 -153 00 -15 50 -152 00 + + e MT STONEY e MT GERDINE + + + e SNOWCAP MOUNTAIN t~ MT SPURR GOLDPAN PEAKe ~NALAKE KENIBUNA LAKE + + + -151 50 + l!l Q) BELUGA LAKE -151 00 -150 50 -ISO 00 62 08 l!l +~ ~ 62 00 C) oSKWENTNA ~ l!l C) C) l!l l!l ~ @ C) ~ l!l l!l WILLOW 0 l!l Q) l!l l!l C) @ CB b I n MT SUSITNA$ l!l Q) ~ FIRE ISLANW C) G) l I UO l!l C) ~i C) '{-,~\.. coo j) BLOCKADE LAKE TURQUOISE LAKE 60 50 + e STERLING <$> + ~ + REDOUBT vcS"LCANO 0 60 50 KALGIN ISLAND ]! 60 33 ~~--------~~~--------~~-----------+--~------~~------------4---~--------r-----------~~~------~~60 33 .., -154 00 -153 50 -153 00 -15? ')[1 -15? [1[1 -151 50 -151 00 -150 50 -150 00 SKILAK LAKE 0 5 10 15 20 M1les ' F*'3 I F3 &3 F3 WOODWARD CLYDE CONSULTANTS 0 5 10 15 20 25 Kilometers NOTE LEGEND REPBRTED MAGNITUDE C) 8 0 C) 7 0 C) 6 0 C) 5 0 (!) 4 0 C) 3 0 "' r 8 [!I No Reported Magmtude INTENSITY <Y XII <Y XI <2)x ~IX <2> VIII <> VII <::) VI ~ v I II Magnrtude symbol s1zes are shown on a contmuous nonlmear scale No DATE REVISION ALASKA PANC!oY!.~~~~THORITY J CHAKACHAMNA HYDROElECTRIC PROJECT t Histone Earthquakes of Focal Depth Less Than 20 M1les m the S1te Reg1on from 1929 Throu h 1980 BECHTEL CIVIL & MINERALS, INC SAN FRANCISCO DESIGNED ENGR SUPV REV F1gure 5-7 '.J I I \ I L I -, I I I ~ \ I I I I ! ) I -~ I I I I I I \ ~ earthquake act1v1ty relat1ve to the Megathrust zone No eartbquahes larger than about Ms 7 5 are hnown to occur alony the Ben1off zone anJ therefore, a max1mun magn1tude ea:tl1quake c: 11s 7 5 1s est1matec for tlJ, s ~one (Wood~ard-Clyde Consultants, 1981) The pr1mary source of earthquakes 1n the crustal or shallow se1sm1C zone 1s Movement along faults or other structures aue to the adJustment of stresses 1n the crust As shown 1n F1gure 5-7, the h1stor1c se1s~1C1ty of the C! 1 Stal zonP w ... thJ.T'l a lar1<= r al.t of tne JtO]ec'- study area 1s low The aata base used to comp1le tne h1stor1c se1sm~c1ty of the crustal zone for th1s study :bas no re""orded earthqllal<es F', the VH'' rnt:y o[ Chakachamna Lake The maJor1ty of the recorded earthquakes shown 1n F1gure 5-7 are located along the eastern and southern marg1ns of the proJect study area Most of these events have not been correlated or assoc1ated w1th any known crustal structures, w1th the poss1ble except1on of one event t:bat 1s assoc1ated w1th the Castle Mounta1n fault As d1scussed 1n Sect1on 5 3 3 3, the Castle Mounta1n fault lS one of the two maJor faults present 1n the proJect study area It passes w1th1n a m1le or less of the proposed proJect fac1l1t1es 1n the McArthur R1ver dra1nage and w1th1n 11 m1les of the proposed fac1l1t1es at Chakachamna Lake Ev1dence for d1splacMent of Holocene depos1ts has been reported 1n the sus1tna lowlands, 1n the v1c1n1ty of the Sus1tna R1ver (Detter~an and others, 1976a) Alth~ugh a number of recorded earthquakes are located along the trend of the Castle Mounta1n fault (F1gure 5-7), only one event, an Ms 7 earthquake 1n 1933, has been assoc1ated w1th the fault 5-71 (Woodward-Clyde Consultants, 1980b) A maximum magnitude earthquake of Ms 7 5 has been est1mated for the Castle Mountain fault (Woodward-Clyde Consultants, 1981) Further studies are needed to assess the poss1ble assoc1at1on of other h1stor1c earthquakes shown 1n Figure 5-7 With cand1date sign1f1cant features Ident1f1ed 1n the fault 1nvest1gat1on phase of the proJect study Because of the prox1m1ty of the proJect s1te to act1ve volcanoes of the Aleut1an Islands-Alaska Pen1nsula volcanic chain, 1nclud1ng Mt Spurr wh1ch IS located 1mmed1ately northeast of the Chahachamna Lake, volcan1c- 1nduced earthquakes are cons1dered a potent1al se1sm1c source Act1ve volcanism can produce small-to-moderace magn1tude earthquakes at moderate-to-shallow depths due to the movement of magma or local adJustments of the earth's crust Occas1onally, severe volcan1c act1v1ty such as phreat1c explos1ons or explos1ve caldera collapses may be accompan1ed by s1gn1ficant earthquake events Because such large volcan1c events are rare, there 1s l1ttle data from wh1ch to estimate earthquake magn1tudes that may be assoc1ated w1th them However, because of the sim1lar1t1es 1n character1st1cs of the Mount St Helens volcano to those of the Aleut1an chain (1nclud1ng Mt Spurr), 1t 1s reasonable to assume that earthquakes assoc1ated w1th the recent Mount St Helens erupt1on of May 1980 may also occur dur1ng future volcan1c activ1ty I J I ~I of Mt Spurr and others In the Aleut1an cha1n The 1~, largest earthquake assoc1ated w1th the Mount St Helens explos1ve erupt1on that occurred on 18 May 1980 had a magn1tude of 5 0 Numerous smaller earthquakes w1th 5-72 r ~ I I l_ I \ ' r , I I I I J I I I I I '~ 5 3 3 5 3 3 1 magn1tudes rang1ng from 3 to 4 were recorded dur1ng the per1od preced1ng the v1olent rupture of Mount St Helens (U s Geolog1cal Survey, 1980) As part of a volcan1c hazard mon1tor1ng program, the U S Geolog1cal Survey has been operat1ng several se1smograph stat1ons 1n the v1c1n1ty of Mt Spurr to assess 1ts act1v1ty Data acqu1red by these stat1ons are not presently ava1lable but w1ll be released 1n 1982 as an Open-F1le Report (Lahr, J c , personal commun1cat1on, 1981) Fault Invest1gat1on Approach The ob]ect1ves of the Chakachamna Lake Hydroelectr1c ProJect se1sm1c geology task are (1) to 1dent1fy and evaluate s1gn1f1cant faults w1th1n the proJect stud} area that may represent a potent1al surface rupture hazard to proJect fac1l1t1es and (2) to make a prel1m1nary evaluat1on of the ground mot1ons (ground shak1ng) to wh1ch proposed proJect fac1l1t1es may be subJected dur1ng earthquakes In order to meet the spec1f1c task ob]ect1ves and to prov1de a general assessment of the se1sm1c hazards 1n the proJect area, the se1sm1c geology study was des1gned and conducted 1n a ser1es of sequent1al phases (F1gure 5-8) 5-73 5 3 3 2 Work to Date The study phases reported here 1nclude rev1ew of ava1lable l1terature, analys1s of remotely sensed data, aer1al f1eld reconna1ssance, and acqu1s1t1on of low-sun- angle aer1al photographs Informat1on of a geolog1c, geomorph1c, and se1smolog1c nature ava1lable 1n the open l1terature was evaluated to 1dent1fy prev1ously reported faults and l1neaments that may be fault related w1th1n the proJect study area Geolog1sts presently work1ng 1n the area or fam1l1ar w1th the study area were also contacted. The locat1ons of all faults and l1neaments der1ved from the l1terature rev1ew and d1scuss1ons w1th other geolog1sts were plotted on 1 250,000-scale topograph1c maps L1neaments 1nterpreted to be fault related were also der1ved from the analys1s of h1gh-alt1tude color-1nfrared (CIR) aer1al photographs (scale 1 60,000) and Landsat 1magery (scale 1 250,000) of the study area outl1ned by the 30-mlle d1ameter c1rcle on F1gure 5-9 These l1neaments were 1n1t1ally plotted (w1th br1ef annotat1on) on clear mylar overlays attached to the photographs and 1mages on wh1ch they were observed The l1neaments were then transferred and plotted on the 1 250,000-scale topograph1c maps The faults and l1neaments 1dent1f1ed from the rev1ew of the ava1lable l1terature and 1nterpretat1on of CIR photographs and landsat 1magery compr1se a prel1m1nary 1nventory of faults and l1neaments w1th1n the study area. The faults and l1neaments 1n the prel1m1nary 1nventory were then screened on the bas1s of a one-th1rd length 5-74 I ~ -, I -l __ : ' I I I I '~ I 1 I ) J I I I r 1 \ I L ; I ( I I I J I ~ ) REVIEW AVAILABLE LITERATURE REMOTE SENSING INTERPRETATION APPLY LENGTH DISTANCE SCREENING CRITERIA WOODWARD CLYDE CONSULTANTS ACQUIRE AND ANALYZE LOW-SUN-ANGLE AERIAL PHOTOGRAPHY IOo DATE REV1SION ALASKA POWER AUTHORITY ANCHORAGE, ALASKA CHAKACHAMMA HYDROELECTRIC PROJECT Se1sm1c Geology lnvest1gat1on Sequence BECHTEL CIVIl & MINERALS, INC CHECKED APP'D DRAWING No REV F1gure 58 I z ,,. .y·" ----1.-1 '· :l .. '; ..... .. , ~-:!·; .,. ~ ... ~· ... - ''1!·:,,, I"'·'"'" : <;r .- -. :~~~"~{-~ ... •. -i- .. ,, ~ ·' < ~- ' .. ·.~ i.. ·j L.:::.;,:--.\:;:_:.;;-;:---'-,~.y-~~-r. ,~' .. _ ';:7:1 -;..r:·--;:;-::·- :.· ' ~~.;r~:...~.! ...:: .. ,. ... -:-;-..-:. ? • '-~ .. EXPLANATION 10 " SCALE IN MILES I~) I I I ~ I I I ~ I I l I I I I I ~J I I -~ L I J I I ~I I I I I r I I I r ~ I I I I length-d1stance cr1ter1on to select those faults and l1neaments w1th1n the study area that potent1all1 could produce surface rupture at s1tes proposed for fac1l1t1es The length-d1stance cr1ter1on spec1f1es a m1n1mum length for a fault or l1neament and a m1n1mum d1stance from the proJect s1te for a fault or l1neament to be reta1ned for further study For example, a fault or l1neament that trends toward the proJect s1te and has an observed length of 10 m1les would be selected for further study 1f 1t was less than 30 m1les from the proJect s1te A fault or l1neament w1th the same trend and same length, but at a d1stance of greater than 30 m1les from the proJect s1te would not be selected for further study The one-th1rd length-d1stance cr1ter1on used 1s based on the emp1r1cal data that suggest that fault rupture rarely occurs along the full length of a fault (except for very short faults) dur1ng an earthquake (Slemmons, 1977, 1980) The length-d1stance cr1ter1on also takes 1nto account ~(1)~ the~poss1b111ty_of_surface rupture w1th1n_or near~to __ the proJect s1te occurr1ng on faults that may be 1dent1f1ed onlt 1n areas remote from the proJect s1te, but wh1ch 1n actual1ty may extend undetected to the proJect s1te, and (2) the fact that at greater d1stances from the proJect s1te, only longer faults would have the potent1al of produc1ng rupture at the s1te Reg1onal faults 1n southern Alaska that are known or 1nferred to be act1ve but are d1stant from the proJect 5-79 study area were not evaluated for surface rupture potent1al. These faults, because of the1r act1v1ty, were cons1dered to be potent1al se1sm1c sources and therefore were evaluated 1n terms of the1r potent1al for caus1ng s1gn1f1cant ground mot1ons at the proJect s1te. I I The faults and l1neaments selected for further study on 1 1 the bas1s of the length-d1stance cr1ter1on or because they appeared to be potent1al sources of s1gn1f1cant ground shak1ng were transferred to 1:63,360-scale topograph1c maps for use dur1ng the aer1al reconna1ssance phase Dur1ng the aer1al reconna1ssance, the faults were exam1ned for ev1dence (geolog1c features, and geomorph1c express1on) that would suggest whether or not youthful act1v1ty has occurred assess. The l1neaments were exam1ned to (1) whether they are or are not faults, and (2) 1f they are not faults, what 1s the1r or1g1n. For those l1neaments that were 1nterpreted to be faults or fault-related, further exam1nat1on was made to look for ev1dence that would be suggest1ve of youthful act1v1ty. After the aer1al reconna1ssance evaluat1on of the faults and l1neaments, each feature was class1f1ed 1nto one of three categor1es (1) a cand1date s1gn1f1cant feature. (2) a non-s1gn1f1cant feature, or (3) an 1ndeterm1nate feature. 5-80 I I ~ I I I I I I I I I I l [I I I I I L_' I i I 5.3.3 3 Cand~date s~gn~f~cant features are those that at some po~nt along the~r length, exh~b~t geolog~c morpholog~c, or vegetat~onal express~ons and character~st~cs that prov~de a strong suggest~on of youthful fault act~v~ty. Non-s~gn~f~cant features are those, wh~ch on the bas~s of the aer~al reconna~ssance, apparently do not possess geolog~c, morpholog~c, or vegetat~onal character~st~cs and/or express~ons suggest~ve of youthful fault act~v~ty. ~t was poss~ble to ~dent~fy non-fault-related or~g~ns for many features ~n th~s category Indeterm~nate features are those l~neaments that posses some geolog~c, morpholog1c, or vegetat~onal character~st1cs or express1ons that suggest the l1neament may be a fault or fault-related feature w~th the poss~b~l1ty of youthful act1v~ty, but for wh1ch the ev~dence 1s not now compell~ng. Cand~date S~gn1f1cant Features The cand~date s1gn~f1cant and ~ndeterm1nate features 1dent1f~ed dur~ng the f1rst four phases of th1s task w1ll requ1re further study ~n order to evaluate the1r> --11--------------------po~en~~a~-ha~a~d-~o-~he-p~oposed-project-fac~~~t~es------------- I i I _, \ I - I I I I I I LJ I I '_J These features occur 1n three pr1nc1pal areas, wh~ch are des1gnated Areas A, B, and C (F~gure 5-9) and are d~scussed 1n the follow~ng sect~ons. The features presented ~n each area are d~scussed 1n terms of the1r prox~m1ty and or1entat1on w1th respect to the nearest proposed proJect fac1l~ty, prev1ous mapp1ng or publ1shed stud1es 1n wh1ch they have been 1dent1f1ed, the1r express1on on CIR photographs, and observat1ons made dur1ng the aer~al reconna1ssance phase of the study. 5-81 Area A Area A 1s bounded by Mt Spurr and the Chakachatna R1ver and Chakachamna Lake and Capps Glac1er CF1gure 5-9}. Four cand1date s1gn1f1cant features, SU 56 and CU 50, CU 52 and SU 150, are located w1th1n th1s area. Feature CU 50 1s a curv1l1near fault that trends roughly east-west and extends from the mouth of the Nag1shlam1na R1ver to Al1ce Glac1er, a d1stance of about 5 m1les. The I 1 I western end of the feature 1s approx1mately 2 m1les north 1 1 of the lake outlet. CU 50 was 1n1t1ally 1dent1f1ed on CIR photographs and 1s character1zed by the al1gnment of (1} l1near slope breaks and steps on r1dges that proJect southward from Mt Spurr, east of Barr1er Glac1er, W1th (2} a l1near dra1nage and depress1on across h1ghly weathered gran1t1c rocks west of Barr1er Glac1er I Dur1ng the aer1al reconna1ssance, d1sturbed bedded volcan1c flows and tuffs were observed on the s1des of canyons where crossed by the feature east of Barr1er Glac1er. These volcan1c rocks are mapped as pr1mar1ly be1ng of Tert1ary age, but locally may be of Quaternary age (Magoon and others, 1976}. The poss1b1l1ty of the d1sturbed volcan1c rocks be1ng of Quaternary age suggests that CU 50 may be a youthful fault. The dense vegetat1on west of Barr1er Glac1er proh1b1ted close exam1nat1on of the fault 1n the gran1t1c terra1n CU 50 1s class1f1ed as a cand1date s1gn1f1cant feature on the bas1s of 1ts close prox1m1ty to proposed proJect 5-82 I I I I I ( I i I fac1l1ty s1tes and because 1t appears to d1splace volcan1c rocks that may be Quaternary 1n age. Feature CU 52 1s a compos1te feature that cons1sts of a fault mapped by Barnes (1966) and prom1nent morpholog1cal features observed on CIR photographs. The feature tends N63°E and extends along the mounta1n front from Capps Glac1er to Crater Peak Glac1er, a d1stance of about 7.5 m1les (F1gure 5-9). The southwestern end of th1s feature 1s approx1mately 8 m1les from the outlet of Chakachamna Lake Along the northeastern port1on of CU 52, from Capps Glac1er to Brogan Glac1eT,-the feature 1s def1ned by a fault that separates Tert1ary gran1t1c rocks from sed1mentary rocks of the Tert1ary West Foreland format1on (Magoon and others, 1976). The southwestern segment, from Brogan Glac1er to the Crater Peak Glac1er, wh1ch extends the mapped fault a d1stance of 3 m1les, was 1dent1f1ed on the bas1s of al1gned l1near breaks 1n slope, dra1nages, and l1tholog1c contrasts Dur1ng the f1eld reconna1ssance, a d1splaced volcan1c flow was observed at the southwest end of the feature. Over most of 1ts length, the fault was observed to be pr1mar1ly ~exposed-1n bedrock-terr--al-n-, -youthfu-l-lateral mora1nes- crossed by the fault d1d not appear to be affected Th1s fault 1s cons1dered to be a cand1date s1gn1f1cant feature because of 1ts prom1nent express1on 1n the Tert1ary sed1mentary and volcan1c rocks crossed by the fault and because of 1ts close prox1m1ty to the proposed proJect fac1l1t1es. In add1t1on, the fault may extend farther to the west along the mounta1n front than was observed on the CIR photographs or dur1ng the br1ef reconna1ssance. If such 1s the case, 1t may connect w1th feature CU 50 5-83 Feature SU 56 cons~sts of two segments, a fault and a ltneament. The comb~ned feature trends N78°E and can be traced from the toe of Barr~er Glac~er to the edge of the mesa l~ke area between the Chakachatna R~ver and Capps Glac~er, a d~stance of about 11 m~les (F~gure 5-9). The western extent of the fault segment ~s unknown, but ~f the l~neament segment, def~ned by a !~near depress~on across the toe of Barr~er Glac~er ~s assoc~ated w~th the fault, ~t may extend ~nto and along the south s1de of Chakachamna Lake, very near the proposed lake tap. SU 56 was recogn~zed on the CIR photographs on the bas~s of the al~gnment of morpholog~c and vegetat~on features· a l1near depress1on across the p1edmont lobe of Barr1er Glac1er, a narrow l1near vegetat1on al1gnment across the alluv~al fan east of and adJacent to Barr1er Glac~er, small subtle scarps between Al1ce and Crater Peak Glac1ers, and a prom1nent scarp and poss~bly a d1splaced volcan~c flow between Crater Peak and Brogan Glac~ers. Dur~ng the f~eld reconna~ssance, all of the character- ~st1cs observed on the CIR photographs could be recogn1zed w~th the except~on of the vegetat1on al~gnment east of Barr1er Glac1er At two locat1ons along the feature, between Al~ce and Brogan Glac1ers, d1splaced volcan1c flows and tuffs were observed At both local1t~es the sense of d~splacement was down on the south s1de relat1ve to the north s~de. The amount of d1splacement could not be measured due to the rugged terra1n at the two locat1ons At the eastern end of the fault, near Brogan Glac1er, the fault ~s on trend and appears to connect w~th one of seven faults observed 1n r~dges along the easts1de of Brogan Glac1er where Barnes (1966) mapped two prom~nent bedrock faults 5-84 Feature SU 56 1s class1f1ed as a cand1date s1gn1f1cant feature because. (1) 1t d1splaces volcan1c rocks that may be of Quaternary age: (2) the l1near depress1on across the toe of Barr1er Glac1er 1s on trend w1th the fault, and (3) the westward pro]ect1on of the feature would pass very close to the proposed proJect fac1l1t1es along the south s1de of Chakachamna Lake. Feature SU 150 1s composed of a ser1es of parallel west-to-northwest-trend1ng faults mapped by Barnes (1966) These faults are located on the Southwest s1de of the mesa=l1ke area between Brogan and Capps Glac1er, approx1mately 12 m1les east of the outlet of Chakachamna Lake (F1gure 5-9). These faults are exposed east of Brogan Glac1er along a nearly vert1cal canyon wall that 1s deeply eroded 1nto Tert1ary sed1mentary rocks mapped as the West Foreland format1on (Magoon and others, 1976) Dur1ng the aer1al reconna1ssance, f1ve add1tonal faults were observed along the wall of the canyon, south of the two faults mapped by Barnes (1966) D1splacement on these faults, as well as on the two mapped by Barnes (1966), appears to be on the order of a few feet to a few tens of feet, w1th the south s1de up relat1ve to the north s1de An except1on to th1s 1s the southernmost fault, on wh1ch the d1splacement appears to be relat1vely up on the north s1de. Dur1ng the aer1al reconna1ssance, the faults could not be traced for any apprec1able :-, d1stance beyond the1r approx1mate length of 2 m1les 5-85 mapped by Barnes (1966). The southernmost fault, wh1ch 1s on trend w1th Feature SU 56, 1s probably an extens1on of that feature The ser1es of faults assoc1ated w1th Feature SU 150 are 1ncluded 1n th1s report as cand1date s1gn1f1cant features because of the probable connect1on of the southernmost fault 1n the ser1es w1th Feature SU 56, wh1ch cons1sts of morpholog1c features that are suggest1ve of youthful fault act1v1ty. Area B Area B 1ncludes the Castle Mounta1n fault and several parallel l1neaments (SU 49, SU 84, and CU 56, F1gure 5-9). The Castle Mounta1n fault 1s one of the maJor reg1onal faults 1n southern Alaska. It trends northeast- southwest and extends from the Copper R1ver bas1n to the Lake Clark area, a d1stance of approx1mately 310 m1les (Be1kman, 1980) The Castle Mounta1n fault crosses the mouth of the McArthur R1ver Canyon near Blockade The Castle Mounta1n fault 1s reported to be an obl1que rlght-lateral fault w1th the north s1de up relat1ve to the south s1de (Grantz, 1966, Detterman and others, 1974, 1976a, b) The Castle Mounta1n fault 1s a prom1nent feature for most of 1ts mapped length The segment northeast of the Sus1tna R1ver 1s def1ned by a ser1es of l1near scarps and prom1nent vegetat1on al1gnments 1n the Sus1tna Lowlands and l1tholog1c contrast 1n the Talkeetna Mounta1ns (Woodward-Clyde Consultants, 1980, Detterman and others, 1974, 1976a). Between the sus1tna and Chakachatna R1vers, the fault 1s less prom1nent but 1s marked by a 5-86 ser1es of slope breaks, scarps, sag ponds, l1tholog1c contrasts, and locally steeply d1pp1ng, sheared sed1mentary rocks that are generally flat to gently d1pp1ng away from the fault (Schmoll and others, 1981; Barnes, 1966)o Southwest of the Chakachatna R1ver, toward the Lake Clark area, the Castle Mounta1n fault 1s well def1ned and expressed by the al1gnment of slope breaks, saddles, benches, l1tholog1c contrasts between pluton1c and sed1mentary rocks, shear zones, and a prom1nent topograph1c trench through the Alaska-Aleutlan Range Bathol1th (Detterman and others, 1976b). D1splacement on the Castle Mounta1n fault has been occurr1ng s1nce about the end of Mesozo1c t1me (Grantz, 1966) The max1mum amount of vert1cal d1splacement 1s about 1 9 m1les or more (Kelley 1963, Grantz, 1966) The max1mum amount of r1ght-lateral d1splacement 1s est1mated by Grantz (1966) to have been several tens of m1les along the eastern traces of the fault Detterman and others (1967 a,b) c1ted 10 m1les as the total amount of rlght- lateral d1splacment that has occurred along the eastern port1on of the fault and about 3 m1les as the max1mum -amount of-rlght~~ateral a1splacement that has occurred along the western port1on, 1n the Lake Clark area. EVldence of Holocene d1splacement has only been observed and documented along a port1on of the Castle Mounta1n fault 1n the Sus1tna Lowland (Detterman and others, 1974i 1976a). Dur1ng the1r 1nvest1gat1on, Detterman and others (1974) found ev1dence suggest1ng that 7.5 ft. of d1p-sl1p movement has occurred w1th1n the last 225 to 1,700 years The amount of hor1zontal d1splacement related to th1s event 1s not known. However, Detterman and others 5-87 (1974) c~ted 23 ft of apparent r~ght-lateral d~splace ment of a sand r~dge crossed by the fault Bruhn (1979), based on two trench,excavat~ons, reported 3 0 to 36ft of d~p-sl~p d~splacement, w~th the north s~de up relat~ve to the south s~de, along predom~nately steeply south- d~pp~ng fault traces He also reported 7 9 ft of r~ght-lateral d~splacement of a r~ver terrace near one of the trench locat~ons. On the CIR photographs, the Castle Mounta~n fault ~s read~ly recogn~zable on the bas~s of the al~gnment of l~near rnorpholog~c and vegetat~on features. The most notable features were observed ~n areas where bedrock ~s exposed at the surface and ~nclude: the prom~nent slope bceak that occurs along the souths~de of Mount Sus~tna and Lone R~dge, the prom~nent bench across the end of the Ch~gm~t Mounta~ns, between the McArthur and Chakachatna R~vers. and the al~gnrnent of glac~al valleys ~n the Alaska Range, one of wh~ch ~s occup~ed by Blockade In areas covered by glac~al depos~ts, the express~on of the Castle Mounta~n ~s more subtle and ~s dom~nantly an al~gnrnent of l~near dra~nages, depress~ons, elongated mounds, and vegetat~on contrasts and al~gnments Based on ~nterpretat~on of the CIR photographs and aer~al reconna~ssance observat~ons, three l~neaments (SU 49 and port~ons of SU 84 and CU 56) are bel~eved to be traces or splays of the Castle Mounta~n fault L~neament SU 49 ~s approx~mately 4 rn~les long, trends northeast, and ~s on l~ne w~th the segment of the fault mapped between Lone R~dge and Mount Sus~tna (F~gure 5-9). SU 49 was ~dent~f~ed on the bas~s of the al~gnment of l~near dra~nages and saddles on a southeast-trend~ng r~dge w~th a vegetat~on contrast ~n the Chakachatna R~ver flood 5-88 pla1n and by a poss1ble r1ght-lateral affect or the east fac1ng escarpment along the west s1de of the Chakachatna R1ver L1neament SU 84 part1ally co1nc1des w1th the mapped trace of the Castle Mounta1n fault southwest of Lone R1dge. At the Chu1tna R1ver, the mapped trace of the Castle Mounta1n fault bends sl1ghtly to the north (F1gure 5-9) whereas l1neament SU 84 cont1nues 1n a more southwesterly d1rect1on. Features along SU 84 that make 1t suspect are the al1gnment of an elongate mound on trend w1th steeply d1pp1ng sed1mentary rocks exposed along the banks of the Chu1tna R1ver and the eroded reentrant along the h1gh bluff on the northeast s1de of the Chakachatna R1ver (N1kola1 escarpment). L1neament CU 56 1s located east of Lone R1dge, 1t trends N70°E 6 1s 7 m1les long, and 1s an echelon to the mapped trend of the Castle Mounta1n fault. CU 56 was 1dent1f1ed on the CIR photographs on the bas1s of the al1gnment of 11near dra1nages and depress1ons and vegetat1on contrasts and al1gnrnents. nur1ng the aer1al reconna1ssance, a ---- -broad zone of-deformed-sechmentary-rocks-was ~bserved on the locat1on where CU 56 crosses the Beluga R1ver. Th1s local1ty co1nc1des w1th a zone of steeply d1pp1ng sed1mentary rocks mapped by Barnes (1966). Area C Area C 1s located south to southeast of the proposed proJect fac1l1t1es s1tes, along the southeastern s1de of the Ch1gm1t Mounta1ns between the North Fork B1g R1ver and McArthur R1ver (F1gure 5-9). Three prom1nent north- east trend1ng parallel features, SU 16, SU 22, and SU 23, 5-89 are located ~n th~s area su 16 ~s an ~nferred fault that transverses both gran~t~c bedrock and glac~al depos~ts su 22 and SU 23 are pr~rnar~ly conf~ned to the gran~t~c bedrock terra~n Feature SU 16 ~s the longest of the three northeast- southwest trend~ng features located ~n ARea C Th~s feature extends from approx~rnately the ~ntersect~on of the McArthur and Kustatan R~vers southwestward across a broad bench ana along the northeast trend~ng segment of the North Fork B~g R~ver, a d~stance of about 25 rn~les (F~yure 5-9) su 16 may extend even farther to the west ~f ~t follows a very l~near glac~al valley that ~s al~yned w~th the northeast trend~ng segment of the North Fork B~g R~ver The northern end of su 16 approaches to w~th~n 10 rn~les of the proposed proJect fac~l~t~es ~n McArthur R~ver area SU 16 was ~dent~f~ed on the CIR photographs and aer~al reconna~ssance on the bas~s of the al~gnment of elongate low h~lls, l~near depress~ons, vegetat~on contrasts, prom~nent slope breaks, and a l~tholog~c contrast that form the broad bench l~ke area between the North Fork B~g R~ver and Kustatan R~vers The southwestern segment of the feature ~s def~ned by the al~gnment of a l~near port~on of the North Fork B~g R~ver and a l~near glac~al valley north of Double Peak Dur~ny the aer~al reconna~ssance, no d~st1nct1ve ev1dence, such as d~splaced l1tholog1c un1ts or bedd~ng or scarps, was observed to conf~rm that su 16 ~s actually a fault Nonetheless, morpholog~c features that were observed do suggest that su 16 ~s a fault and that 1t may be a youthful fault. 5-90 SU 16 ~s ~ncluded ~n th~s report as a cand~date s~gn~f~cant fault because the morpholog~c features observed on the CIR photographs and dur~ng the aer~al reconna~ssance strongly suggest that ~t ~s a fault and may be a youthful fault. Features SU 22 and SU 23 (F~gure 5-9) are both northeast trend~ng l~near to curv~l~near faults that parallel one another at a d~stance of about one m~le. Feature SU 22 can be traced from about the McArthur R~ver southwestward to Black Peak, a d~stance of about 16 m~les Feature su 23 ~s approx~mately 8 m~les ~n length and extends from Blacksand Creek southwestward to the north Fork B~g R~ver area. The northeastern ends of the two features (SU 22 and SU 23) approach to w~th~n 8 m~les of proposed pro]ect fac~l~ty s~tes ~n the McArthur R~ver area Both features were recogn~zed on CIR photographs and are def~ned by the al~gnment of prom~nent l~near troughs that are part~ally occup~ed by small lakes and ponds, scarps, slope breaks, benches, and saddles. Dur~ng the aer~al reconna~ssance, the two features could -be-read~ly traced~across~be-dr_o-ck Eerra~n-(rnappe-a as Jurass~c to Cretaceous-Tert~ary gran~t~c rock, Magoon and others, 1976) on the bas~s of the~r morpholog~c features Sl~cken-s~ded and pol~shed surfaces were observed at several of the scarps and slope break local~t~es exam~ned; sheared zones were also observed dur~ng the reconna~ssance. The southwestern port~ons of both features are located ~n very rugged terra~n and are poorly def~ned due to the h~ghly JO~nted gran~t~c rocks that are present along th~s segment 5-91 At the northern end, 1n the v1c1n1ty of Blacksand Creek, SU 23 appears to splay out w1th one trace trend1ng toward su 22 and one trace trend1ng toward su 16 (F1gure 5-9). SU 22 also appears to d1e out 1n the v1c1n1ty of Blacksand Creek, although there was a subtle tonal al1gnment observed on the CIR photographs on the north s1de of the creek that suggests 1t may extend across Blacksand Creek toward the McArthur R1ver SU 22 and SU 23 are 1ncluded as cand1date s1gn1f1cant features because the1r prom1nent express1on suggests that they are maJor structures and that they may be assoc1ated w1th SU 16 wh1ch 1s cons1dered_a fault w1th poss1ble youthful act1v1ty. Area D Area D (F1gure 5-9) 1ncludes the Bru1n Bay fault, wh1ch 1s one of the maJor reg1onal faults 1n southern Alaska. The Bru1n Bay fault 1s a northeast-trend1ng, moderate-to- steeply-northwest-d1pplng reverse fault that extends along the northwest s1de of the Cook Inlet from near Mount sus1tna to Bechalaf Lake, a d1stance of about 320 m1les (Detterman and others, 1976b). The fault approaches as close as approx1mately 30 m1les south to southwest of the proposed proJect fac1l1t1es at Chakachamna Lake and approx1mately 20 m1les of the proJect fac1l1t1es 1n the McArthur R1ver. The northern segment of the Bru1n Bay fault, from about the Dr1ft R1ver area to Mount sus1tna, 1s proJected beneath surf1c1al depos1ts from 1ts last bedrock exposure north of Katch1n Creek. The proJeCtlon 1s based on a prom1nent l1near depress1on across Kustat1an R1dge, 5-92 al~gnment of l~near lakes and depress~ons ~n the lowland area west and north of Tyonek, and h~ghly d~sturbed and faulted Tert~ary sed~mentary rocks along the Chu~tna and Beluga R~ver (Detterman and others, l976b, Magoon and others, 1976, Schmoll and others, 1981) ' To the south of Katch~n Creek, where the fault ~s exposed ~n bedrock areas, the trace of the fault ~s commonly marked by a zone of crushed rock a few to several hundred meters w~de and saddles or notcheb (Detterman and others, l976b) The sense of d~splacement along the fault ~s reverse w~th the north s~de up relat~ve to the south s~de (Magoon and others, 1976, Detterman and others, l976b) Detterman and Hartsock (l96b) reported left-laterdl d~splacement of 6 m~les or less has occurred along the fault ~n the In~sk~n-Tuxedn~ reg1on, southwest of the study area The youngest un~t reported d~splaced by the Bru~n Bay fault ~s the Tert~ary sed1mentary Beluga format~on (Magoon and others 1 1976) No d~splacement of Holocene surf~c~al depos~ts between Katch~n Creek and the probable JUnct~on of the fault w~th Castle Mounta~n fault near Mt sus~tna has been observed or documented (Detterman and others Dur~ng the analys~s of the CIR photographs, several subtle to prom~nent d~scont~nuous l~neaments were ~dent~f~ed along the projected trend of the Bru~n Bay fault across the McArthur and Chakachatna R~ver flood pla~ns near the Cook Inlet, and along the lowland area west of Tyonek The l~neaments were exam~ned dur~ng the aer~al reconna~ssance and no d~splacement or d~sturbed Holocene depos~ts were observed Several of the l~neaments, however, d~d co~nc~de w~th d~sturbed or faulted sed~mentary rocks of the Beluga format~on exposed 5-93 5.3.3.4 along the Chu1tna and Beluga R1vers. Further work 1s needed to assess whether the glac1al and/or fluv1al depos1ts overly1ng the sed1mentary bedrock have been faulted or d1sturbed. Although no ev1dence has been observed or reported that would 1nd1cate youthful fault act1v1ty along the Bru1n Bay fault, several of the l1neaments observed on the CIR photographs are suggest1ve of youthful fault act1v1ty. On the bas1s of the l1neaments along the proJected trace of the Bru1n Bay fault, and the fact that the fault 1s suspected to 1ntersect w1th the Castle Mounta1n fault, the Bru1n Bay fault 1s cons1dered for th1s report to be a cand1date s1gn1f1cant feature Impl1cat1ons w1th Respect to the Proposed Hydroelectr1c ProJect Based on the results of the work to date a prel1m1nary assessment can be made regard1ng the potent1al surface 1 fault1ng hazards and se1sm1c sources of ground mot1on (shak1ng) w1th respect to the proposed proJect s1te (1) W1th1n the study area, faults and l1neaments 1n four areas have been 1dent1f1ed for further evaluat1on 1n order to assess and better understand the1r potent1al effect on proJect cons1derat1ons For example, 1f feature su 56 1s an act1ve fault, 1ts trend 1s toward the area proposed for the lake tap and the extent and act1v1ty of th1s feature clearly requ1re evaluat1on Several of these features may prove to be capable of produc1ng earthquakes, thus both ground shak1ng and surface rupture 1n the proJect area 5-94 5.4 (2) The Castle Mounta1n fault 1s located along the southeast s1de of the Ch1gm1t Mounta1ns at the mouth of McArthur Canyon Although no d1splacements of Holocene depos1ts have been observed or reported for the segment of the castle Mounta1n fault between the sus1tna R1ver and the Lake Clark area, the fault 1s cons1dered an act1ve fault on the bas1s of the reported d1splacement of Holocene depos1ts east of the proJect area 1n the v1c1n1ty of the sus1tna R1ver. (3) Based on a rev1ew of the ava1lable l1terature and deta1led stud1es conducted for maJor proJects 1n southern Alaska there are three potent1al se1sm1c sources that may have an effect on the proJect s1te. These 1nclude· the subduct1on zone, wh1ch cons1sts of the Megathrust and Ben1off zone, crustal se1sm1c zone, and severe volcan1c act1v1ty. The Castle Mounta1n fault (crustal se1sm1c source) and the Megathrust segment of the subduct1on zone are expected to be the most cr1t1cal to the proJect w1th respect to levels of peak ground accelerat1on, dura1:tonof strongshak1ng, and development of response spectra (see sect1on 7 4). References Barnes, F. F., 1966, Geology and coal resources of the Beluga-Yentna Reg1on, Alaska: U s. Geolog1cal Survey Bullet1n 1202-C, 54 p Be1kman, H. M., comp1ler, 1974, Prel1m1nary geolog1c map of the southeast quadrant of Alaska. U s. Geolog1cal 5-95 survey M~scellaneous F1eld Stud1es Map MF-612, scale 1.1;000,000 Be1kman, H. M.; comp1ler, 1980, Geolog1c map of Alaska: u.s. Geolog1cal Survey, scale 1.2,500,000. Bruhn, R. L., 1979, Holocene d~splacement measured by trench1ng the Castle Mounta~n fault near Houston, Alaska. Alaska D1v~s1on of Geolog1cal and Geophys1cal Surveys, Geolog1cal Report 61, 4 p. Bureau of Reclamat1on, Chakachamna ProJect Alaska - Status report March, 1962. Bureau of Reclamat1on, Alaska D1str1ct Off1ce, Juneau, Alaska, unpubl1shed report, 21 p. Capps, s. R., 1935, The southern Alaska Range: u.s. Geolog1cal Survey Bullet1n 862, 101 p. Detterman, R L., and Hartsock, J K., 1966, Geology of the In1sk1n-Tuxedn1 Reg~on, Alaska: u.s. Geolog1cal survey Profess1onal Paper 512, 78 p. Detterman, R. L., Plafker, G. Hudson T., Tysdal, R. G., and Pavon1, N. 1974, Surface geology and Holocene breaks along the Sus1tna segment of the Castle Mounta1n fault, Alaska: u s Geolog1cal Survey M1scellaneous F1eld Stud1es Map MF-618, scale 1.24,000. Detterman, R. L , Plafker, G., Tysdal, R. 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R., 1971, Aftershock zones of great earth- quakes, se1Sm1c1ty gaps, and earthquake pred1ct1on for Alaska and the Aleut1ans Journal of Geophys1cal Research, v 76, p 8021-8041. Tarr, R. s., and Mart1n, L , 1912, The earthquakes at Yakutat Bay, Alaska 1n September 1899 U. s Geolog1cal Survey Profess1onal Paper 69, 135 p. TenBrlnk, N W , and R1tter, D. F , 1980, Glac1al chronology of the north-central Alaska Range and 1mpl1cat1ons for d1scovery of early man s1tes. Geolog1cal Soc1ety of Arner1ca, Abstracts w1th Programs, 1980, p. 534. TenBrlnk, N w., and Waythomas, c. F , 1n preparat1on, Late W1scons1n glac1al chronology of the north-central Alaska Range - a reg1onal synthes1s and 1ts 1mpl1cat1ons for early man settlements Thatcher, W , and Plafker, G , 1977, 1899 Yakutat Bay, Alaska Earthquakes. Se1smograms and Crustal Deformat1on (-Abs ) -Geo-]:-oglcal-soc1ety of--Arner 1-ca Ab-stracts-Wl tn Programs, v 9, p. 515. Tra1ner, F. W, and Waller, R M., 1965, Subsurface strat1graphy of glac1al dr1ft at Anchorage, Alaska u. S Geolog1cal Survey Profess1onal Paper 525-D, p Dl67-Dl74 U. s Geolog1cal Survey, 1980, Volcano Log· Mount St. Helens, 1980, Spall, H, (ed ), 1n Earthquake Informat1on Bullet1n. u. s Geolog1cal Survey, July-August 1980, v. 12, no 4, p 142-149. 5-101 W1ll1ams, J. R , and Ferr1nas, o. J., 1961, Late W1scons1n and recent h1story of the Matanuska Glac1er, Alaska. Arct1c, v. 14, no. 1, p. 83-90. Woodward-Clyde Consultants, 1978, Offshore Alaska se1sm1c exposure study Prepared for Alaska Subarct1c Operators' comm1ttee (ASOC), March, 1978, v. 1 through 5. woodward-Clyde Consultants, 1979, Reconna1ssance Geolo9y, Bradley Lake Hydroelectr1c ProJect. Contract No DACW 85-79-C-0045, Department of the Army, Alaska D1str1ct, Corps of Eng1neers, 65 p. woodward-Clyde Consultants, 1980a, Se1sm1c1ty study Bradley Lake Hydroelectr1c ProJect. Contract No DACW 85-79-C-0045 Mod1f1cat1on POOOl, Department of the Army, Alaska D1str1ct, Corps of Eng1neers, 35 p. Woodward-Clyde Consultants, 1980b, Inter1m Report on se1sm1c Stud1es for sus1tna Hydroelectr1c ProJect for Acres Amer1can Incorporated. Alaska Power Author1ty, sus1tna Hydroelectr1c ProJect, Subtask 4.01 through 4.08. woodward-Clyde Consultants, 1981, Draft Report Bradley Lake Hydroelectr1c ProJect Des1gn Earthquake Study· Contract No. DACW 85-79-C-0045 Mod1f1cat1on 0005, Department 1of the Army, Alaska D1str1ct, Corps of Eng1neers, 53 p. 5-102 ENVIRONMENTAL STUDIES 6GO ENVIRONMENTAL STUDIES -SUMMARY Env1ronmental stud1es were conducted w1th1n the Chakachatna and McArthur R1ver dra1nages dur1ng both 1981 and 1982. The 1981 stud1es 1ncluded 1nvest1gat1ons of the hydrology, aquat1c and terrestr1al b1ology and human resources of the area. These stud1es were l1m1ted 1n scope due to the short-t1me frame wh1ch was ava1lable for conduct1ng f1eld 1nvest1gat1ons. Stud1es conducted 1n 1982 emphas1zed aquat1c b1olog1cal 1nvest1gat1ons (seasonal sampl1ng) , but also 1ncluded supplemental hydrolog1cal stud1es. The follow1ng sect1on presents summary 1nformat1on for each of the 1981-1982 stud1es. The complete deta1led reports for the env1ronmental stud1es are presented 1n the APPENDIX to Sect1on 6.0 1n Volume II of th1s report. 6.1 Env1ronmental Stud1es -1981 6.1.1 In 1981, two env1ronmental reconna1ssance level surveys were conducted 1n the proJect areaG The f1rst was conducted 1n August to document the presence of sockeye salmon (Oncorhynchus nerka) 1n the proJeCt waters, and to survey the s1te 1n preparat1on for the fall f1eld reconna1ssance. The second 1nvest1gat1on, conducted 1n m1d-September, 1nvolved two weeks of f1eld data collect1on. Co1nc1dent w1th these stud1es were ongo1ng rev1ews of the l1terature and d1scuss1ons w1th key agency and nat1ve corporat1on personnel. Env1ronmental Hydrology Hydrology f1eld stud1es were conducted for Chakachamna Lake, several of 1ts tr1butary streams, and the 6-1 Chakachatna and McArthur R1vers. The hydrolog1c f1eld data collected 1ncluded measurements of d1scharge taken at e1ght study locat1ons, a water level survey of Chakachatna Lake, a wetland/r1ver level survey taken 1n a channel of the Noaukta Slough, and a character1zat1on of channel pattern and COQf1gurat1on 1nclud1ng the compos1t1on of bed and bank mater1als. Off1ce evaluat1ons were also conducted to synthes1ze hydrolog1c data at e1ght study locat1ons. Data that were developed 1ncluded mean monthly flows, mean annual flows, flood flow frequency, and low flow frequency. In add1t1on, us1ng the Montana Method, prel1m1nary 1nstream flow recommendat1ons for ma1nta1n1ng f1sher1es hab1tat were calculated on a monthly bas1s for the outlet of Chakachamna Lake. The f1eld data collected from the var1ous streams were typ1cal of glac1al r1vers, w1th low flows 1n late w1nter, large glac1er melt flows 1n July and August, and annual peaks due to fall ra1ns. The reaches of the McArthur and Chakachatna R1vers vary from mounta1nous through bra1ded and meander1ng streams. All except the most 1nfrequent large floods are conta1ned w1th1n the unvegetated flood plan. Sed1mentat1on character1st1cs 1n the streams appear to be typ1cal of glac1al systems w1th very f1ne suspended sed1ments and substant1al bed load transport. The water level of Chakachamna Lake (measured 1n September) was 1,142 feet wh1ch was typ1cal for the lake 1n September based on 12 years of past records. 6-2 r 6.1.2 Aquat1c B1ology Two reconna1ssance level surveys were conducted 1n \ Chakachamna Lake, and 1n the Chakachatna, Ch1ll1gan and McArthur R1vers and tr1butar1es. The f1rst reconna1s- sance occurred dur1ng 17-18 August and cons1sted of aer1al observat1ons of the proJect area. The second reconna1ssance, conducted 15-28 September, 1nvolved the collect1on of data from areas 1dent1f1ed dur1ng the 1n1t1al survey. Th1s effort employed both f1eld sampl1ng and v1sual observat1ons. The maJor ob]ect1ves of th1s reconna1ssance were to 1dent1fy the f1sh spec1es and l1fe stages dur1ng the fall, to 1dent1fy potent1al cr1t1cal f1sher1es hab1tats 1n the system, and to prov1de 1nformat1on on the spec1es compos1t1on of f1sh and the1r hab1tat use occurr1ng at d1fferent t1mes of the year. A total of 14 spec1es of f1sh were collected from the waters of the proJect area 1nclud1ng all f1ve spec1es of Pac1f1c salmon found 1n Alaska (Table 6.1). Some of the streams flow1ng 1nto Chakachamna Lake conta1ned large areas used by sockeye salmon for spawn1ng. Substant1al numbers of sockeye were found 1n the Ig1tna and Ch1ll1gan R1vers, and there was some ev1dence of potent1al sockeye spawn1ng 1n Chakachamna Lake. Juven1le sockeye salmon used Chakachamna and Ken1buna Lakes as nursery hab1tat. Lake trout (Salvel1nus namaycush) , Dolly Varden (Salvel1nus malma) , round wh1tef1sh (Prosop1um cyl1ndraceum) and sl1my sculp1n (Cottus cognatus) were also found 1n Chakachamna Lake. S1de channels and tr1butar1es of the Chakachatna and McArthur R1vers conta1ned salmon1d spawn1ng s1tes and 6-3 a\ I "'"' Table 6.1 Spec1es l1st and dra1nage of occurrence August-September 1981. Spec1es pygmy wh1.tef1.sh ProSOJ21Um coulter1 round whl.tefJ.sh ProSOJ2l.Um c~l1ndraceum Dolly Varden Salvel1nus mal rna lake trout Salvel.1nus namaycush rcunbow trout Salmo ga1.rdner1 punk salmon Oncorh~nchus 9:orbuscha chum salmon Oncorhynchus keta coho salmon Oncorhynchus k.1sutch sockeye salmon Oncorhx:nchus nerka ch.1nook salmon Oncorh~nchus tshawxtscha arct1.c grayl.1ng Thymallus arct1cus sl1my sculpun Cottus cognatus threesp.1.ne st1ckleback Gasterosteus aculeatus n1nesp.1ne st1ckleback Pun91t1us pun~;p. t1. us 1 Includes Lake Chakachamna and M1ddle R1ver ~ -, I I I '~ --\ 1,_ .-J - Dra1na9e of Occurrence Chakachatna McArthur Rl.verl R.lver + + + + + + + + + + + + + + + + + + + + + + + + + + numerous f1sh were observed us1ng them. These hab1tats were also used as ]uven1le rear1ng areas. The Noaukta Slough, a heav1ly bra1ded reach of the Chakachatna R1ver, was used extens1vely as a nursery area by ]Uven1le f1shes, part1cularly coho (Oncorhynchus k1sutch) and sockeye salmon. Juven1le pygmy wh1tef1sh (Prosop1um coulter1) and Dolly Varden were also abundant 1n the slough. The 1ntert1dal ranges of both r1ver systems do not conta1n su1table hab1tat for salmon1d spawn1ng or JUven1le rear1ng. Lake trout appeared to occur only 1n Chakachamna Lake, wh1le Dolly Varden were ub1qu1tous throughout both the Chakachatna R1ver and McArthur dra1nages. Ra1nbow trout (Salmo ga1rdner1) were collected only 1n the lower port1ons of the dra1nages. Round and pygmy wh1tef1sh were found 1n most areas of the dra1nages, although pygmy wh1tef1sh were not found 1n Chakachamna Lake or dra1nages above 1t. Sl1my sculp1n were found throughout both systems and 1n tr1butary streams. Stlcklebacks, however, were only found 1n backwater areas and among vegetat1on, usually 1n the lower reaches of the r1vers. Only a s1ngle grayl1ng (Thymallus arct1cus) was observed 1n a s1de channel 1n the upper Nag1shlam1na R1ver, and none were collected or observed at any other locat1on. It was clear that most of the spec1es found 1nhab1t both dra1nages In general, the f1sh 1n th1s area may be class1f1ed 1nto two pr1mary groups, forage f1sh, and commerc1al and sport f1sh. Forage f1sh 1n the proJect area 1nclude threesp1ne st1ckleback (Gasterosteus aculeatus) , n1nesp1ne st1ckleback (Pung1t1us pung1t1us) , sl1my sculp1n, pygmy wh1tef1sh, and round wh1tef1sh. 6-5 Although the round wh~tef~sh ~s probably not used as a subs~stence spec1es 1n these dra1nages, 1t 1s eaten by lake trout and other spec1es of f1sh. Sport and commer- C1al f1shes 1nclude p1nk (Oncorhynchus gorbuscha), chum (Oncorhynchus keta), sockeye, coho and ch1nook salmon (Oncorhynchus tshawytscha) , and Dolly Varden, lake trout, ra~nbow trout, and grayl1ngo Terrestr1al Vegetat1on and W1ldl1fe The obJeCt1ve of the terrestr1al component for the env1ronmental study was to character~ze the vegetat1ve and w1ldl1fe commun1t1es w1th1n the proJect area. Because th1s proJect would affect the lands and waters of both the Chakachatna and McArthur dra1nage systems, qual1tat1ve data were collected throughout the study area and vegetat1on and w1ldl1fe hab1tat maps were prepared so that areas of a sens1t1ve or cr1t1cal nature could be 1dent1f1edo Prev1ous 1nvest1gat1ons conducted 1n the general area by the Alaskan Department of F1sh and Game (ADF&G) and the U.S. F1sh and W1ldl1fe Serv1ce (USFWS) have concentrated on document1ng waterfowl ut1l~zat1on of the coastal marshes of Cook Inlet. In add~t1on to annual aer1al surveys of the Trad~ng Bay State Game Refuge performed by the personnel of ADF&G, personnel of USFWS have conducted aer1al swan surveys encompass1ng the lands 1n and adJacent to the refuge. Although the ma1n purpose of these surveys has been to census waterfowl, 1nformat1on has also been gathered on bald eagle nest s1tes, moose calv1ng grounds, and the occurrence of Beluga whales near the McArthur R1ver. 6-6 ~ I -.J I Table 6.2 The spec~es compos~t~on and re1at~ve abundance of mammals 1dent~f~ed w~th~n the study area for each of the hab1tat types Spec~es gr1.zzly bear Ursus horrl.bl.ll.s black bear Ursus amer~canus gray wolf Can1s lUEUS coyote Canl.s Iatrans moose Alces alces barren ground car1bou Rang1fer arct1cus wolverl.ne Gulo luscus m.1.nk Mustela v1son r1ver otter Lutra canadens1s beaver Castor canadens1s muskrat Ondatra z1beth1ca red squ1rrel Tam1asc1urus hudson1cus tundra redback vole Clethr1onom~s rut1lus tundra vole M1crot1s oeconomus porcup1ne Ereth1zon dorsatum dusky shrewb Sorex obscurus harbor seal b Pfioca v1tul~na beluga whale DelJ2hl.naeterus leucas a Upland Alder Th1cket (UAT) , H1gh Alt1tude R1par1an (HAR), Black Cottonwood R1par1an (BCR~, Coastal Marsh R1par1an (CMR), Black Spruce Trans1t1onal (BST), ResJ.n BJ.rch Bog (RBB), W1llow Th1cket R1par1an (STR) , and Black Spruce R1par1an (BSR) UAT 3 1 5 3 5 5 5 5 1 3 b sJ.ghted offshore near the mouth of the McArthur R1ver. (!=Abundant J=Common 5=0ccaslonal) Hab1tata HAR BCR CMR BST RBB WTR BSR 1 3 J 5 5 3 3 1 3 3 5 3 3 J 3 5 5 5 5 3 3 1 3 3 J 3 1 1 3 3 3 3 3 5 5 5 5 5 5 3 5 3 5 5 5 3 3 3 5 3 3 3 5 5 5 5 5 3 3 3 3 3 3 3 3 5 3 3 5 5 6.1.4 Dur1ng the 1981 stud1es, e1ght types of vegetat1on hab1tats were del1neated based on the1r structural and spec1es compos1t1on. These ranged from dense alder th1ckets 1n the canyons to vast areas of coastal marsh. The r1par1an commun1t1es were the most prevalent, vary1ng from r1vers w1th emergent vegetat1on to those w1th broad floodpla1ns scattered w1th l1chen, w1llow and alder. Evaluat1on of w1ldl1fe commun1t1es 1n the proJect area 1dent1f1ed s1xteen spec1es of mammals (Table 6.2). Moose, coyote, gr1zzly bear and black bear occur throughout the area. B1rds also were abundant, f1fty-s1x spec1es hav1ng been 1dent1f1ed, w1th the coastal marshes along Trad1ng Bay conta1n1ng the largest d1vers1ty. None of the spec1es of plants, mammals and b1rds that were found are l1sted as threatened or endangered, although 1n May 1981 1t was proposed that the tule wh1te-fronted goose, wh1ch nests 1mmed1ately south of the study area, be cons1dered for threatened or endangered status. Human Resources These stud1es were organ1zed 1nto the follow1ng s1x elements Archaeolog1cal and h1stor1cal resources Land ownersh1p and use Recreat1onal resources Soc1oeconom1c character1st1cs Transportat1on V1sual resources 6-8 I I r~ I I I ) I I I I I I I I I I :_] I I J I I I I I I I L~ ll I I I l l r i I I I ) I I I ( ' I I I L1 I I I I \---,1 I I I Contacts w~th both state and federal agenc~es and Nat~ve organ~zat~ons, and a l~m~ted reconna~ssance of the proJect area were made dur~ng the 1981 stud~eso No known cultural s1tes were ~dent~f~ed and the f~eld reconna~ssance ~nd~cated that the proposed s1tes for the power 1ntake and powerhouses have a low potent1al for cultural Slteso Land owners 1n the area compr1se federal, state, and borough agenc1es, Nat1ve Corporat1ons and pr1vate art1es Land use 1s related to resource extract1on (t1mber, 011 and gas), subs1stence, and the rural res1dent1al Vlllage of Tyonek. Recreat1onal act1v~ty occurs but l1ttle data 1s ava1lable to the extent or frequency w1th wh1ch the area lS used. Reg1onal data on populat1on, employment and 1ncome character1st1cs are relat1vely good. However, employment level and occupat1onal sk~ll data are l1m~tedand need to be developed together w1th 1nformat1on on local employment preferences. Transportat1on fac1l1t1es 1n the area are few and small 1n s1ze. There 1s an a1rstr~p on the shorel~ne at Trad1ng Bay and a woodch1p load1ng p1er near Tyonek. Several m1les of logg~ng roads ex1st between Tyonek and the mouth of the Chakachatna Valley. The Chakachatna R1ver 1s br1dged near 1ts confluence w1th Stra1ght Creek There ~s no permanent road between the proJect area and any part of the Alaska road system. Because of the proJect area's scen1c character1st~cs and ~ts prox~m~ty w~th BLM lands, the Lake Clark Nat1onal 6-9 Park and the Trad1ng Bay State Game Refuge, v1sual resource management 1s a s1gn1f1cant concern. 6.2 Env1ronmental Stud1es -1982 6.2.1 The 1982 env1ronmental stud1es 1ncluded both hydrolog1cal and aquat1c b1olog1cal 1nvest1gat1ons w1th pr1mary emphas1s on the lattero The hydrolog1c stud1es were conducted dur1ng the fall of 1982 {August and October) , aquat1c b1olog1cal stud1es were conducted seasonally, w1th the maJor sampl1ng effort occurr1ng dur1ng the summer and fall per1ods. Env1ronmental Hydrology The ob]ect1ve of the 1982 env1ronmental hydrology stud1es was to collect basel1ne data to ass1st 1n future evaluat1ons of the phys1cal process of the Chakachatna and McArthur R1ver systems, and fac1l1tate the correlat1on of these processes w1th f1sh and w1ldl1fe hab1tats. Dur1ng August, two record1ng gages capable of record1ng r1ver stage and water temperature were 1nstalled, one on the Chakachatna R1ver near the lake outlet, the other on the McArthur R1ver downstream of the powerhouse locat1on. Staff gages were 1nstalled at an add1t1onal 15 s1tes and were per1od1cally mon1tored. In October, d1scharge measurements and water surface prof1les were made at 12 gage stat1ons, and a general1zed sed1ment character1zat1on made for the var1ous stream reaches. Mann1ng's equat1on was used 1n the hydraul1c analyses to establ1sh prel1m1nary rat1ng curves. 6-10 J ( I I I J i I I I I I I I - I I I I -I il : I I I I I I I I I I l __ I_' ( I I 1 I I I ~J - I I ) I I_ r l l Overall, the d~scharges at gauge s~te No. 6 ~n the lower Chakachatna R~ver, downstream of the fork wh~ch d~scharges ~nto the Noaukta slough but above the spl1t w1th the M~ddle R1ver, correlated reasonably well w1th the d1scharges at the Chakachatna R1ver record1ng gage at the lake outlet. The flows averaged about 17 percent of the flow at the lake outlet. The average d~scharge at the lake outlet dur~ng the study per1od was s1gn1f~cantly less than the average for the 13 years of U.S.G.S records, w1th August flows well below average A September ra1nstorm resulted 1n a short durat1on flood flow rn the upper McArthur R~ver w1th a peak flow of about 4500 cfs Th~s d~scharge ~s est1mated to have a recurrence ~nterval of about 25 years. Mean da1ly water temperatures ~n the Chakachatna R1ver at the lake outlet ranged from a0 c 1n August to 6°C 1n October. Water temperatures 1n the McArthur R1ver at the rap1ds exh1b~ted large d~urnal var1at1ons 1n August, 0 0 temperatures var~ed from 3.0 C to 9.5 C ~n a s1x-hour per~od Temperatures 1n the McArthur R~ver 0 from m~d-August to m1d-September averaged 1.6 C less at the powerhouse than at the record1ng gage. The Chakachatna and McArthur R1ver systems are glac1al and thus carry f1ne glac1al s1lts through much of theopen water season. The ma~n channel substrate of these r1ver systems appears to be qu1te unstable. Aquat~c B~ology The 1982 aquat~c b1ology stud~es concentrated on the f1shery resources of the study area. Two ser~es of programs were conducted, one dur1ng the w1nter and 6-11 spring, the other during the summer and falle The winter-spring studies were designed to extend the data base on seasonal habitat use and distribution of fish, to Identify the time spring spawning migration begins, and to examine for the presence of outmigrants. The summer-fall studies were directed at Investigating both the adult anadromous fish, and the resident and Juvenile anadromous fish In the study areas. A separate program for sampling the fisheries In Chakachamna Lake was also conducted during the summer-fall studies. A variety of methodologies were utilized to sample and count fish In the study area during the 1982 program. Selected sampling techniques Included the use of fyke nets, minnow traps, seines, hook and line, electrofishing, and gill netting. Hydroacoustic sampling was used to examine the relative distribution of fish In Chakachamna Lake. A total of 18 fish species were Identified and/or collected during the 1982 studies, Including four species not collected In 1981· Bering cisco (Coregonus laurettae), longfin smelt (Spirinchus thaleichthys), rainbow smelt (Osmerus mordax and eulachon (Thaleichthys pacificus) • The species of commercial, subsistence and sport Interest utilizing the Chakachatna and McArthur River systems Included sockeye, chinook, pink, chum and coho salmon, Dolly Varden and rainbow trout. Summary Information for these seven species IS presented below. Detailed analyses o~ the 1982 studies are presented In the APPENDIX to Section 6.0 In Volume 2 of this report. 6-12 I l I l_i : I I L J il I I I I I l_j \ L I 6.2.2.1 Sockeye Salmon Sockeye salmon adults probably enter the Chakachatna and the McArthur R1vers 1n early July. Sockeye f1rst appeared on the spawn1ng streams on July 22, 1982. Spawn1ng cont1nued through the f1rst week of October 1n var1ous parts of the system and few spawn1ng sockeye were present past early October. The t1m1ng and durat1on of sockeye-runs var1ed w1th locat1on. Runs 1n the McArthur R1ver tr1butar1es peaked earl1er than most of those on the Chakachatna R1ver. Spawn1ng adults were present 1n the Ch1ll1gan R1ver and sloughs at stat1on 17 longer than at other s1tes. Sockeye escapements were est1mated for all 1dent1f1ed spawn1ng areas and are presented 1n Table 6 3. The largest est1mated escapement was for the Ch1ll1gan R1ver: 38,576 sockeye. A total of 41,357 sockeye (total of the Ig1tna and Ch1ll1gan R1ver escapements) were est1mated to spawn above Lake Chakachamna. Of the other sockeye est1mated to spawn 1n the Chakachatna dra1nage, 1788 spawned 1n sloughs or s1de channel spawn1ng areas rece1v1ng slough flow. In the McArthur dra1nage, of the 34,933 f1sh, 98.1 percent of the est1mated sockeye escapement occurred 1n tr1butary streams. Overall, 44.7 percent of the total est1mated escapement of sockeye occurred 1n the McArthur dra1nage Sockeye wh1ch are spawned 1n the Ch1ll1gan and Ig1tna R1vers, rear 1n Chakachamna and Ken1buna Lakes. The Chakachatna R1ver across from Stra1ght Creek, the Noaukta Slough, and port1ons of the lower McArthur R1ver also appear to be used as rear1ng areas. Juven1le 6-13 Table 6 3 Summary of est1mated salmon escapement by waterbody and drainage for 1982 cRAKACHATNA RIVER DRAINAGE Chakachatna Straight Bridge Chakachatna Chakachatna Straight Creek Creek Side Channels Canyon Tr1butary Ig1tna Ch1l hgan Stra1ght Clearwater Drainage Species Mouth and Sloughs Sloughs (Cl) R1Ver River Creek Tributary Total Sockeye Salmon 203 1.193 392 238 2.781 38.576 0 254 43.637 Chmoo!t Salmon 0 0 0 0 0 0 0 1.422 1.422 Pink Salmon 0 59 279 0 0 0 0 7.925 8.263 Chum Salmon 152 1.482 121 165 0 0 0 0 1.920 Coho Salmon 76 1.560 608 183 0 0 0 172 2.599 -----------------------------------------------------------------------------------------------------------------------------------------------------0'1 I MCARTHUR RiVER DRAINAGE ..... ~ Streams Drafnage Species McArthur Canyon Stream 13X Stream 13U 12 I 12 2 12 :J 12 ~ 12 ~ Total Sockeye Salmon 666 5.416 1.213 16.711 6.085 2.512 2.328 0 34.933 Chinook Salmon 0 452 1.633 0 22 0 0 0 2.107 P1nk Salmon 60 4,225 5,402 8.499 1.566 4 18 3 19.777 Chum Salmon 1 0 23 4 0 0 1 0 29 Coho Salmon 1,182 1.378 32 2,000 46 89 0 0 lil.729 Nole F1gure 6 30 shows locat1ons 111 Cf>akachalna H1ver riramal)e F1gures S 30, 6 4 7 and 6 48 sho.-l locat1ons m McArthur River dra111agc J --1 I __ ~ sockeye appear to rear ~n the system from as short a t~me as the~r f~rst summer to as long as the~r th~rd year (age II+) pr~or to m~grat~ng to the sea. 6 2.2.2 Ch~nook Salmon Based upon 1982 observat~ons, ch~nook salmon adults were enter~ng the r~ver systems pr~or to late June. Ch~nook spawn~ng was f~rst observed ~n the study area on July 17 at Stream 13U ~n the McArthur system, but spawn~ng could have started as early as the end of June. Spawn~ng adults were observed as late as August 25. The largest est~mated escapement for ch~nook salmon occurred ~n Stream 13U ~n the McArthur dra~nage (1633 f~sh) and the second largest ~n the clearwater tr~butary to Stra~ght Creek (1422 f~sh) (Table 6.3). All ch~nook spawn~ng observed dur~ng 1982 occurred ~n tr~butary streams. The ma]or~ty of spawn~ng occurred w~th~n the McArthur dra~nage Ch~nook salmon Juven~les rear ~n fresh water from as short as three months to well 1nto the~r th~rd year of l~fe. Juven~le ch~nook salmon collected ~n the study area ranged ~n age from O+ to II+. Ch~nook salmon Juven~le rear~ng areas cons~sted of spawn~ng streams (Streams 13U and 19), low veloc~ty s~de channel and slough areas (stat~ons 17, 15 and 13) and many areas w~th~n the Noaukta Slough. Ch~nook outm~grat~on may start as early as June and appears to cont~nue ~nto the fall. 6-15 Fish collected are listed by method and sampling location. Locations of the sampl~ng stat~ons are as follows Station Number 1 1D 2 3 4 5 6 6A 8 9 10 li 12 13 14 15 16 16A 17 17D 18 19 19A 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Streams Streams Stream Stream Stream Location Confluence of Chakachatna River with McArthur River McArthur River Lower Chakachatna R~ver Lower Chakachatna River Upper Middle River Lower Middle River Chakachatna River above Middle River Chakachatna River above M~ddle River Upper Nouakta Slough Lower Nouakta Slough West Nouakta Slough Lower McArthur River McArthur River above Noaukta Slough Upper McArthur River Lower McArthur Canyon McArthur Canyon Upper Noaukta Slough Upper Noaukta Slough Chakachatna River at DNR Bridge Chakachatna River Below 17 Straight Creek Clearwater tributary to Straight Creek Clearwater tributary to Straight Creek Chakachatna River across from Straight Creek Chakachatna River across from Stra~ght Creek Chakachatna River at base of canyon Chakachatna River in canyon Chakachatna River in canyon Chakachamna Lake Nagishlamina River Chakachamna Lake N Chakachamna Lake S delta Side Side Kenibuna Lake outlet Chilligan River Neacola River Igitna River Another River 12.1 through 12 4p 13X 12 1 through 12 4 12.5 13U 13U 6-16 / Map Coordinate R 14 W., T R 14 Wq T. R 14 W , T. R 14 W , T R 14 W , T R. 13 w I T R 14 W , T 10 N 10 N liN liN liN liN liN R 14 W., T 11 N R 14 W , T 11 N R. 14 W., T 11 N R. 15 W • T. 11 N R. 14 W , T 10 N R. 15 W , T 11 N R 16 W , T 11 N R 16 W , T 12 N R 17 W., T. 12 N R 14 W , T 12 N R 14 W , T 11 N R 14 W , T 12 N R 14 W , T 12 N R 15 W , T 12 N R 14 W , T 12 N R. 14 W , T 12 N R 15 W , T 12 N R 15 W , T 12 N R. 15 W T 13 N R 15 W , T 13 N R 16 W , T 13 N R. 17 W., T 13 N R 18 W , T 13 N R. 18 W., T 13 N R. 18 W , T 13 N R. 20 W , T 13 N R. 20 W , T 13 N R 21 W., T 12 N R. 21 W , T 12 N R 21 W , T 13 N R 15 W., T 11 N R 15 W., T 12 N R. 14 w I T 11 N R. 15 W., T. 11 N R. 16 W., T. 11 N I I I I I : I I I '---- I I I I I II I I I j ~ 1 I a 1 2 3 4 s I ! I I miles I ~~~I 0 Recordmg Gauge Locat1on 0 Staff Gauge Locat1on a Samplmg Stat1on 0 Sampling Stat1on Only FfGURE 6 30 I-~, I ~J LOCATION AND IDENTIFICATION OF 1982 SAMPLING STATIONS 14 13 ~ M1lhng Areas ~ MILES -N- 0 1/2 ~ 18 ----3 --...... --·~L- ~ ..-.- -... ~~ ... _, ..:..· Figure 6 47 Sockeye Milling Areas Streams 13X. 12 1, 12 2, 12.3 1982 ·~ - .. E Milling Areas MILES 1/2 O> ~DI ....... ee~========~~ -I! &.. F Milling Area Sockeye 13u at Stream 1982 6.2.2.3 P1nk Salmon P1nk salmon were f1rst observed m1ll1ng 1n fresh water 1n late July (July 22) and f1rst observed 1n the spawn1ng streams on July 31. P1nks cont1nued to be observed 1n the McArthur and Chakachatna R1ver tr1butar1es unt1l m1d-September w1th peak counts made 1n August. In Cook Inlet, p1nk salmon runs 1n even numbered years are generally larger than runs occurr1ng dur1ng odd numbered years. S1nce 1982 was an even year, larger than averaEe escapements were expected. However, prel1m1nary commerc1al catch data 1nd1cate that 1982 had a lower than average run for an even-numbered year. Est1mated escapements for the var1ous water bod1es 1n the system are shown 1n Table 6 3. The vast ma]or1ty of p1nk spawn1ng occurred 1n tr1butary streams. In the Chakachatna dra1nage, 4.1 percent of the 8,263 est1mated p1nk escapement for that dra1nage occurred 1n sloughs and s1de channels, and 1n the McArthur dra1nage less than 0.3 percent of the est1mated p1nk escapement occurred 1n sloughs or s1de channels. The ma]or1ty of the total est1mated p1nk escapement, 70.5 percent or 19,777 f1sh, occurred 1n the McArthur dra1nage. No p1nks spawned above the sloughs at the base of the Chakachatna R1ver Canyon. Emergent p1nk salmon fry probably move d1rectly down r1ver to the sea. Rear1ng 1n fresh water may be for a per1od as short as one day, and thus, no rear1ng areas were 1dent1f1ed dur1ng the 1981 and 1982 stud1es. 6-21 6.2.2.4 Chum Salmon Chum salmon were 1n the spawn1ng streams on August 25 and were found at most spawn1ng areas by September 1 The total est1mated spawn1ngs escapement for both the Chakachatna and McArthur R1ver dra1nages was 1949 f1sh, wh1ch was less than any of the other four salmon spec1es (Table 6.3). The ma]or1ty of these f1sh (77 percent - 1481 f1sh) spawned 1n the sloughs at stat1on 17 on the Chakachatna R1ver. Over 90 percent of the est1mated escapement occurred 1n sloughs or areas rece1v1ng upwell1ng flow In early June, chum salmon fry had moved 1nto lower port1ons of the r1ver systems and smolts were found at collect1ng stat1ons near the mouth of the McArthur R1ver. By the end of June, only a few smolts were collected near the mouth of the McArthur R1ver, suggest1ng that the peak downstream m1grat1on had occurred. Because of the relat1vely short rear1ng per1od of chum salmon 1n freshwater, no spec1f1c rear1ng areas were 1dent1f1ed dur1ng the 1981-1982 stud1es. 6.2.2.5 Coho Salmon Coho salmon were f1rst observed 1n fresh water 1n mld-August. At that t1me fa1rly large numbers of coho were observed m1ll1ng at the mouths of streams on the McArthur R1ver. Coho were observed on spawn1ng streams on September 1 and peak numbers were observed 1n m1d to late September 1n most water bod1es. Spawn1ng was st1ll 1n progress when the study was concluded 1n late October and may have cont1nued under the 1ce 1n the Chakachatna Canyon sloughs. 6-22 The ma]or1ty (64.5 percent) of the est1mated total coho escapement for the study area occurred 1n the McArthur R1ver. In the McArthur system, 75 percent (3547 f1sh) of the est1mated escapement of 4729 coho occurred 1n tr1butar1es (Table 6.3) The other 25.0 percent took place 1n s1de channel and slough areas. Spawn1ng occurred 1n both tr1butar1es and sloughs. The ma]or1ty (86.3 percent) of the est1mated escapement of 2599 coho 1n the Chakachatna dra1nage were observed 1n sloughs and s1de channels rece1v1ng upwell1ng or slough flow No coho were observed spawn1ng above the Chakachatna Canyon sloughs. Yolk-sac fry and emergent fry were found 1n spawn1ng areas 1n the study area 1n late March. Coho ]Uven1les may rema1n 1n fresh water for up to four years Coho of up to age II+ were common 1n the Chakachatna and McArthur R1ver systems. Juven1le coho salmon were among the more w1dely d1str1buted f1sh present 1n the study area below the lakeo Coho Juvenlles were generally abundant 1n tr1butar1es, the Noaukta Sough, and areas 1n the lower port1ons of both r1vers. Observed 1ncreases 1n the abundance of coho 1n the Noaukta Slough, lower r1ver systems and upper McArthur R1ver probably repre- sented a comb1nat1on of movement to overw1nter1ng hab1tat and outm1grat1on. The outm1grat1on of some coho was conf1rmed by the collect1on of smelts 1n the lower port1ons of the r1vers. Coho smelts were collected 1n the Chakachatna and McArthur R1ver systems from early June 1nto October. 6-23 6.2.2.6 Dolly Varden Dolly Varden was the most w1dely d1str1buted spec1es collected 1n the study area and was found at almost every s1te at wh1ch f1sh were collected. They numer1cally dom1nated collect1ons made below Chakachamna Lake. Dolly Varden may be res1dent or anadromous, both types are probably present w1th1n the study area. Dolly Varden were obsereved spawn1ng from July 31 through October 1n the Ch1ll1gan R1ver Dur1ng late October, sexually mature upstream m1grants were st1ll be1ng collected 1n the lower portons of the r1ver systems, and Dolly Varden spawn1ng was st1ll occurr1ng. Dolly Varden spawn1ng was also common 1n the McArthur R1ver and 1ts tr1butar1es dur1ng October Some upstream m1grants wh1ch spawned 1n the McArthur R1ver were observed enter1ng the r1ver systems from the M1ddle R1ver and then mov1ng through the Chakachatna R1ver. Dolly Varden JUVen1les were w1dely d1str1buted 1n the r1ver systems. They were collected from every r1ver sampled, 1nclud1ng the the Neacola and Another R1vers. Juven1le (ages I+ to II+) appear to be common throughout the r1ver system w1th larger, older f1sh, 1nclud1ng age III+, more abundant 1n the Noaukta Slough and lower port1ons of the r1ver. Dolly Varden appear to move freely w1th1n and between the two r1ver systems. 6.2.2.7 Ra1nbow Trout Ra1nbow trout were regularly collected 1n port1ons of the lower r1ver systems and tr1butar1es. Ra1nbow trout 6-24 were collected most frequently 1n October when large numbers had moved 1nto the lower r1ver system. L1ttle 1s known about the spawn1ng of ra1nbow trout 1n the Chakackatna and McArthur R1ver systems and few ra1nbow trout under 10 em (4.0 1nches) were collected. The d1str1but1on of ra1nbow trout 1n the Chakachatna R1ver appears to be l1m1ted to areas below the Chakachatna R1ver Canyon. Dur1ng the summer and fall of 1982, Juven1le ra1nbow trout were collected 1n the Stra1ght Creek clearwater tr1butary (19) , 1n the McArthur R1ver (Stat1ons 13, and 11) and 1n the lower Chakachatna R1ver (Stat1ons 3, 4, and 6). Ra1nbow trout are a res1dent spec1es and therefore rear 1n freshwater throughout the year. Based upon tag return data, ra1nbow trout appear to move freely w1th1n and between the rn1ddle and lower port1ons of both r1ver systems. 6-25 EVALUATION OF ALTERNATIVES 7.0 7.1 EVALUATION OF ALTERNATIVES Eng1neer1ng Evaluat1on General The f1gures quoted 1n th1s sect1on of the report for the est1mated cost of energy are cons1dered to be conservat1ve for two bas1c reasons, the f1rst be1ng that 1n the power stud1es for Alternat1ves A, B, C and D, the max1mum lake level was taken as elevat1on 1128 wh1ch had been reported as the approx1mate 1nvert elevat1on of the natural lake outlet channel The natural max1mum lake water level 1s reported to have been at about elevat1on 1155 and the records show that the lake rose to that level or w1th1n about 5-feet of 1t each year No cred1t has been taken 1n the calculat1ons for any add1t1onal energy that would accrue from the h1gher heads that would temporar1ly be ava1lable when the lake water level exceeded elevat1on 1128. There 1s also the poss1b1l1ty that once d1vers1on of water for power generat1on beg1ns, the outlet channel may choke and 1ts 1nvert may r1se above 1ts present elevat1on thus creat1ng a h1gher head for power generat1on. If the max1mum water level 1s taken, as elevat1on 1142, the 1nstalled capac1ty for Alternat1ve B would 1ncrease from 330 MW to 350 MW and the average annual energy would r1se by 6% from 1446 GWh to 1533 GWh. The second reason wh1ch appl1es to Alternat1ves A, B, c, D and E, 1s because of the real1st1c approach taken to est1mat1ng the cost of construct1ng each of the alternat1ves. Analyses were made of b1ds rece1ved for 7-1 proJects 1nvolv1ng s1m1lar types of construct1on and the un1t pr1ces used 1n the est1mates are cons1stent w1th those that have been rece1ved 1n recent compet1t1ve b1dd1ng 1n cases where the analyses have perm1tted such compar1sons to be drawno Furthermore, although the est1mates make allowances for certa1n lengths of the tunnels where product1on may sl1p and costs may 1ncrease due to adverse rock cond1t1ons, an overall 20% cont1ngency allowance over and above the est1mated cost of construct1on, eng1neer1ng and construct1on management has been 1ncluded 1n arr1v1ng at the est1mated total proJect costs. Chakachatna Dam On the bas1s of what was seen 1n surface exposures dur1ng reconna1sances of the Chakachatna Valley, l1ttle encouragement could be found for pursu1ng a course based on the concept of s1t1ng a dam anywhere 1n the valley downstream from the lake outlet. Although the poss1b1l1ty has not been completely ruled out, 1t 1s cons1dered most unl1kely that JUSt1f1cat1on for s1t1ng a dam here could be conf1rmed. Alternat1ve A Th1s alternat1ve, wh1ch would take all controlled water from Chakachamna Lake for the generat1on of electr1cal power 1n a powerplant located 1n the McArthur Valley, 1s the most advantageous 1dent1f1ed by the present stud1es when regarded str1ctly from the po1nt of v1ew of power generat1on. As may be seen by reference to Table 7-1, the powerplant would have the max1mum 1nstalled capac1ty (400 MW) , and would y1eld the max1mum average annual f1rm 7-2 I I I~ I I 1 ~ ' r I I I I ~ I t' \ \ J I I I I ~ J ' I lJ I~ I I L -"> i I \ \ I_J , r 1 I \ I I I 1 ~ -::r - l I I \ II TABLE 7-1 COST OF ENERGY Alternat1ve Installed capac1ty-MW Annual generat1on-GWh Deduct 5% for transm1ss1on losses and stat1on serv1ce-GWh F1rm annual energy-GWh Cap1tal cost 1nclud1ng IDC at 3% -$B1ll1ons (1) Annual cost 3.99% 1nclud1ng A 400 1752 88 1664 1.5 B 330 1446 72 1374 1 o45 1 II 1nterest, amort1zat1on and 1-' 1nsurance for 50-year I 1 proJect l1fe -$M1ll1ons 59.9 57.9 Net cost of energy -Mllls/kWh 36 42 I O&M -Mllls/kWh 1G5 1.5 Total cost of energy -Mllls/kWh 37.5 43G5 ~ I I I I (1) Exclud1ng Owner's costs and escalat1on. l \ i) L I I ~ 7-3 c D E 300 300 330 1314 1314 1301 66 66 65 1248 1248 1236 1.6 1.65 1.32 63.8 65.8 52.7 51 53 43 1.5 1 5 1 5 52.5 54.5 44.5 energy (1664 GWh) at the lowest un1t cost (37.5 m1lls per kWh) o It 1s cons1dered that these f1gures can safely be regarded as conservat1ve for the reasons set forth 1n Sect1on 7.1.1 above. Th1s alternat1ve would prov1de ne1ther 1nstream flow releases nor f1sh passage fac1l1t1es at the lake outlet and should, therefore, be regarded as a hypothet1cal case g1v1ng the theoret1cal max1mum energy potent1al that could be developed. Alternat1ve B Th1s alternat1ve follows the same bas1c layout as that for Alternat1ve A, but approx1mately 19% of the average annual flow of water 1nto Chakachamna Lake, dur1ng the per1od of outflow gauge records, would be reserved for release 1nto the Chakachamna R1ver near the lake outlet, to sat1sfy the tentat1ve m1n1mum 1nstream flow requ1re- ments d1scussed 1n Sect1on 7.3.2 of th1s report. Th1s would cause the 1nstalled capac1ty to be reduced from 400 MW to 330 MW. The average annual f1rm energy would reduce to 1374 GWh at a un1t rate of 43.5 m1lls/kWh. Th1s 1s 16% h1gher 1n cost than for Alternat1ve A but 1s st1ll s1gn1f1cantly less than the 55.6 m1llsjkWh wh1ch 1s the est1mated cost of energy from the most compet1t1ve thermal source, a coal f1red plant, as d1scussed 1n Sect1on 9.4 of th1s report. Alternat1ve B has the advantage that 1nstream flows are prov1ded 1n the Chakachamna R1ver for support of 1ts f1shery and based on the tentat1ve amount of water reserved for these 1nstream flow requ1rements, the proJect would st1ll be an econom1cally v1able source of energy. 7-5 7.1 5 Alternative B does not Include a design concept for a fish passage facility that would maintain a means of entry Into and exit from Chakachamna Lake for migrating fish but an allowance for the cost of one was Included In the estimate. A concept was developed In the 1982 studies and Is discussed below In Section 7.1.6, Alternative E. Alternatives C and D Both of these alternatives would divert water from Chakachamna Lake to a powerplant located near the downstream end of the Chakachamna Valley. For Alternative C, all controlled water would be used for power generation. For Alternative D, water required to meet the Instream flow releases discussed In Section 7.3.3 of the report would not be available for power generation. This water amounts to 30 cubic feet per second average annually, which IS less than 1% of the total water supply. Being that small, It can be Ignored at the present level of study. As may be seen from Table 7-1, the Installed capacity for both Alternatives C and D would be 300 MW. The average annual firm energy would be 1314 GWh at 52.5 mills/kWh for Alternative C and 54.5 mills/kWh for Alternative D. The Installed capacity and energy that would be generated by Alternatives C and D are significantly less than In the case of both Alternatives A and B, and the cost of energy Is significantly higher. Alternatives C and D are Inferior In comparison with Alternatives A and B as sources of hydro power. At 55.6 mills/kWh, energy from a coal fired plant would be only marginally more expensive than the energy that could be generated by Implementing Alternatives c or D. 7-6 't r I I ,--;_ I I I '~ I ~ I l I I I ' I l I 7.1.6 Alternatl.ve E Thl.s alternatl.ve l.ncorporates all the prl.ncl.pal features of the power facl.ll.tl.es for Alternatl.ve B. In addl.tl.on, the normal maxl.rnum opratl.ng water level l.n Chakachamna Lake would be ral.sed to El. 1155, whl.ch l.S reported as the hl.gh lake water level under natural condl.tl.ons, by constructl.ng an overflow rockfl.ll dl.ke l.n the natural outlet channel. The dl.ke Wl.ll provl.de an artl.fl.cl.al barrl.er such as the natural barrl.ers that have bul.lt up l.n the past for varl.ous perl.ods of tl.me before they were washed away durl.ng the passage of lake outbreak floods. The artl.fl.cl.al barrl.er would be protected agal.nst overtoppl.ng by an unll.ned spl.llway channel excavated l.n rock on the rl.ght abutment. Materl.al excavated to form thl.s channel would be used to construct the dl.ke. The dl.scharge capac1.ty of the channel would be l.n the order of 50,000-60,000 cfs but future studl.es of flood hydrology are needed to establl.sh the approprl.ate capacl.ty. Flood dl.scharges exceedl.ng the desl.gned channel capacl.ty would be dl.scharged over and through the rockfl.ll dl.ke. Sl.nce the only foundatl.on aval.lable for a dl.ke at thl.s locatl.on l.S the glacl.al deposl.ted rock and gravel whl.ch undergoes small movements, l.nterrnl.ttent mal.ntenance wl.ll be requl.red. Thl.s could be performed each year, or as requl.red, durl.ng the sprl.ng whl.le the lake level l.S drawn down below the level of the dl.ke foundatl.on. The normal operatl.ng range of lake level wl.ll be 72 feet, from El. 1155 to El. 1083o Thl.s wl.ll support a capacl.ty of 330 MW at 50% load factor except for 1-month durl.ng 7-7 7.2 7 2 1 the 31 year extended hydrolog1cal record, or a true f1rm capac1ty of 330 MW at 45% load factor throughout the ent1re per1od. The average annual f1rm energy will be 1301 GWh at a un1t cost of 44.5 m1lls/kWh. Fac1l1ties w1ll be prov1ded for the d1scharge of 1nstream flow releases to the Chakachatna R1ver, and for the upstream and downstream passage of f1sh 1nto and out of the lake over the full operat1ng range of lake water level. Geological Evaluation Chakachatna Dam Although su1table dam s1tes might appear to ex1st 1n the canyon l1ke topography along the Chakachatna R1ver about s1x miles downstream from Chakachamna Lake, the geolog1c characterist1cs of the canyon suggest that construct1on of a maJor dam there 1s unl1kely to prove feas1ble, and 1f such construct1on 1s attempted, 1t 1s l1kely to be very costly and a complex engineer1ng problem for the reasons discussed below. As discussed In Section 5 2.2, there 1s a marked difference 1n the bedrock from one side of the Chakachatna Canyon to the other. The south side of the canyon cons1sts of a steep wall of glac1ated gran1te, wh1ch appears to be well suited for a dam abutment. In contrast, the north wall of the canyon exposes a complex of geologic un1ts dominated by lava flows, pyroclastics, and volcaniclastics, but Including outwash and f1ll. If the 1deas presented 1n Sect1on 5.2.2.2 are bas1cally correct, the volcanics may overlie alluv1um below the present valley floor, both the volcan1cs and the alluv1um \ 7-8 1 ' I \ I ) I I \ - I \ I I I J 1--, I I, \ I I ' I I L~ ) L' l LJ (t \, LJ ( I I I l J (I lv ---, I I 1 I I I h_o 7.2.2 rest on gran1t1c bedrock at an unknown depth below the valley floor In add1t1on to spec1f1c adverse foundat1on cond1t1ons suggested by depos1ts found on the north valley wall (e g. h1gh permeab1l1t1es, low strength), the chaot1c character of those depos1ts would make the pred1ct1on of foundat1on cond1t1ons at a g1ven s1te very d1ff1cult. Any 1mpoundment 1n the Chakachatna Canyon w1ll be subJect to the volcan1c hazards assoc1ated w1th Mt. Spurr (Sect1on 5.2.2 2). The youthfulness of Mt. Spurr, as a whole, and the fact that 1t has been act1ve 1n h1stor1c t1me suggest that cont1nued erupt1ve act1v1ty should be factored 1n as a des1gn cons1derat1on for any fac1l1t1es 1n the Chakachatna Canyon. Alternat1ve A On the bas1s of the observat1ons made dur1ng the 1981 f1eld program, 1t 1s poss1ble to comment on several geologlC factors that may lnfluence cons1derat10n of Alternat1ves A, B and E, (see also Sect1ons 5.2.1.6, 5.2.2.3, 5.2.3 4, and 5.2.3.3.). (1) (2) Although any lake tap s1te between the lake outlet and F1rst Po1nt Glac1er would be subJect to 1mpact from a very large erupt1on of Mt. Spurr, no s1te 1n that area 1s l1kely to be d1sturbed by Crater Peak type events (Sect1on 5.2.2.2) 0 The bedrock character1st1cs pert1nent to tunnell1ng have not been spec1f1cally stud1ed, 7-9 (3) th1s should be a subJect of future study. General observat1ons 1n the Chakachatna Canyon, aer1al observat1ons of snow-and-lee-free bed~ rock exposures between the Chakachatna and McArthur canyons, and general observat1ons 1n the McArthur Canyon suggest that bedrock cond1t1ons are llkely to be well su1ted to tunnel construct1on, w1th the except1on of the lowermost port1on of the canyon, near the Castle Mounta1n fault. The Castle Mounta1n fault, wh1ch has had Holocene act1v1ty along at least part of 1ts length, 1s present near the mouth of the canyon and has apparently d1srupted the bedrock (shears, 1ntense ]01nt1ng) 1n the lower reaches of the canyon. For any proJect fac1l1t1es constructed 1n the fault zone, there would be a r1sk assoc1ated w1th fault rupture: large ground mot1ons would l1kely occur dur1ng an earthquake on the fault. One of the des1gn alternat1ves presented 1n th1s report 1nclude fac1l1t1es 1n the fault zone, as 1t 1s now known. Add1t1onal work 1s needed 1n future explorat1ons of th1s area. \ Slope cond1t1ons above both the proposed lake tap s1te and outlet portal s1te are generally s1m1lar 1n that there 1s no ev1dence of large-scale slope movements 1n the recent past and rockfall appears to be the dom1nant slope process. Talus at the base of the slope at the proposed outlet portal/powerhouse s1te (F1gures 3-1, 3-2) suggests a s1gn1f1cant amount of rockfall act1v1ty 1n post-glac1al t1me. 7-10 I ! I I I I I l \ I \ a 1 I I \ ~1 ~ I \ I J I 1 -1 n I ~ ~ I I \ l-1 I \ (_ f ~~ zJ ,--1 I : ) =-- I L_ I -I I I L1 I (, __ , I I I I I ~- rr I_ ----, I l) I I I I J 7.2.4 (4) As d1scussed ln Sect1on 5.2"1.4, a s1gn1f1cant advance of Blockade Glac1er could d1srupt dra1nage 1n and near the lower reaches of the McArthur Canyon. There was no ev1dence 1dent1f1ed dur1ng the 1981 f1eld work to suggest that such an event 1s l1kely 1n the near future. Alternat1ve B The comments 1n Sect1on 7.2.2 apply to th1s alternat1ve, also. Alternat1ves C and D On the bas1s of the observat1ons made dur1ng the 1981 f1eld program, 1t 1s poss1ble to comment on several geolog1c factors that may 1nfluence cons1derat1on of Des1gn Alternat1ve C (and D), see also Sect1ons 5.2al.6, 5.2.2.3, 5.2.3.4, and 5.3.3.3. (1) ( 2) In th1s alternat1ve, both ends of the hydroelectr1c system would be subJect to the volcan1c hazards assoc1ated w1th Mt. Spurr. Comment No. 1 for Alternat1ve A (Sect1on 7.2.2) appl1es here, also. Volcan1cally-1nduced flood1ng 1s JUdged to be the volcan1c hazard most l1kely to affect the outlet portal/powerhouse s1te (F1gure 3-3) 1n the Chakachatna canyon. On the bas1s of general observat1ons (1.e., not observat1ons spec1f1cally des1gned to assess tunnell1ng cond1t1ons), the gran1t1c rock types that predom1nate 1n the area of the proposed 7-11 7.2.5 ( 3) tunnel al1gnment (F1gure 3-3) are generally well su1ted for tunnell1ng. Local zones of 1ntens1ve weather1ng, alterat1on, or extens1ve ]01nt1ng and shear1ng may prov1de poor tunnell1ng cond1t1onse The slopes above both the lake tap and outlet portal s1tes cons1st of glac1ated gran1t1c bedrock. No ev1dence of large-scale slope fa1lure was observed dur1ng the 1981 reconna1ssance f1eld work. Rockfall appears to be the dom1nant slope process. Alternat1ve E The comments regard1ng the power fac1l1t1es 1n Sect1on 7.2.2 apply equally to th1s a~ternat1ve. The follo~1ng comments apply to the fac1l1t1es proposed to be located 1n the general v1c1n1ty of the lake outlet. (1) The 1nlet portal for the structures requ1red for 1nstream flow releases and f1sh passage fac1l1t1es w1ll be located 1n glac1ated gran1t1c bedrock. No ev1dence of large-scale slope fa1lure was observed 1n th1s area. (2) ( 3) The sp1llway channel w1ll be excavated 1n the same glac1ated gran1t1c bedrock. The approach channels to the f1sh passage fac1l1t1es and sp1llway w1ll be excavated 1n fluv1al sed1ments depos1ted 1n a fan to the south of the lake outlete 7-12 J I !' I I l I II I \ _j '~, ( l LJ ~l L- ~~-l I tJ ~~ I L_' I' I I L• r~ Ll \ \ ~! (( l_l ~ I ( J_J 7.3 (4) Tunnell1ng cond1t1ons for the f1sh passage flumes and 1nstream flow releases w1ll be as descr1bed 1n Sect1on 7.2.4 (2) for the power tunnel 1n Alternat1ves C and D. (5) The outlet structure and lower part of the f1sh passage flumes downstream from the tunnel portal w1ll be constructed as a cut and cover structure 1n outwash mater1als and alluv1um. ( 6) The left abutment and r1ver channel sect1on of the d1ke w1ll be constructed on debr1s covered glac1al 1ce. The r1ght abutment w1ll be on glac1ated gran1t1c rock. Env1ronmental Evaluat1on The prel1m1nary env1ronmental overv1ews presented 1n the I follow1ng sect1ons for each proJect alternat1ve are based on data obta1ned from agency personnel, ava1lable l1terature, and the 1nformat1on collected dur1ng the 1981 and 1982 f1eld programs. Although a complete evaluat1on of all 1nfluences of each alternat1ve 1s not 1ncluded 1n th1s sect1on, the ant1c1pated maJor effects of each alternat1ve are presented. These potent1al effects should not be cons1dered def1n1t1ve, and are only 1ncluded at th1s t1me to fac1l1tate compar1sons of the alternat1ves. The recommended Alternat1ve E 1s d1scussed 1n more deta1l and the effects on aquat1c and terrestr1al b1olog1cal resources are 1dent1f1ed. 7-13 7.3.1 Chakachatna Dam Alternat1ve If a dam was constructed and operated on the Chakachatna R1ver, 1t 1s l1kely that substant1ve adverse 1mpacts would be 1nfl1cted on f1sh of the Chakachatna dra1nage. A f1sh passage fac1l1ty, somewhat s1m1lar to that descr1bed for Alternat1ve E, would be necessary to preserve stocks of anadromous f1sh wh1ch spawn above Chakachamna Lake. If such passage was not prov1ded the 41,000 sockeye wh1ch are est1mated to spawn above the lake (Sect1on 6 8.3) and the1r contr1but1on to the Cook Inlet F1shery would be lost. The Dolly Varden populat1on wh1ch m1grate to and spawn 1n tr1butar1es above Chakachamna Lake would also be lost. If passage was ma1nta1ned 1mpacts to those populat1ons could be s1m1lar to Alternat1ve E. S1t1ng of the dam at the mouth of the canyon would result 1n the loss of slough spawn1ng hab1tat for coho, p1nk, sockeye, and chum salmon and Dolly Varden 1n that area (Sect1on 6.8.3). Due to the water qual1ty alterat1ons 1n the r1ver down- stream from the dam, the use of some f1sh m1gratory and rear1ng hab1tat may be reduced. Th1s, 1n turn, could adversely 1mpact Cook Inlet commerc1al f1shery resources. If a large decl1ne 1n the lake f1shery occurred, wolves, bears, and eagles would probably m1grate to lower elevat1ons, thus 1ncreas1ng the dens1ty of an1mals 1n the rema1n1ng forage areas. Other large mammals that ord1nar1ly ut1l1ze the Chakachatna R1ver canyon for m1grat1on to and from summer and w1nter range would 7-14 , r I l I l 1 I I '.-J I ~ ' I i \ J I j n f I ll I I _) I --, 1l I I l ) I I - I I '_j I ~1 I I ~ I I J : r I_ I r---"-) I I I \ J probably also be Impacted. Since the canyon area upstream from the darn would be flooded, a high quality visual resource w1ll be affected by the loss of the white-water reach of the rivere In addition, fluctuating Chakacharnna Lake water levels associated with all alternatives w1ll Impact the scenic quality of the lake shorelinee If the lake levels are raised so that the tributary deltas are Inundated, additional JUvenile rearing and spawning areas may be created for resident lake fish, (primarily lake trout) and anadrornous fish If passage past the darn IS rnaintaineda Although fishing and hunting access to the lake by wheeled airplanes would be reduced, access by float p~ane will be unaffected. Construction Impacts due to this alternative would be more extensive tnan other alternatives where less area would be affected and where the need for such large volumes of construction materials IS not required. Although the Impacts from this alternative may be severe In that a maJor fishery could be adversely affected or lost, many of the Impacts, Including the damage to the aquatic resources, potentially could be mitigated, primarily through the Installation of appropriate fish passage structures. McArthur Tunnel Alternatives A and B Through the Implementation of Alternatives A or B, the Impacts resulting from construction and logistical support activities would be very similar. In these alternatives, although the maJor Impacts most likely will 7-15 be 1nfl1cted on local f1sh and w1ldl1fe, human and v1sual resources w1ll also be affected. For example, w1th 1ncreased access to the McArthur Canyon and Chakachamna Lake, 1mportant v1sual resources as well as f1sher1es and w1ldl1fe hab1tat may be degradedo Once 1n operat1on, the 1ncreased flows 1n the McArthur R1ver may result 1n changes 1n water qual1ty and alterat1ons 1n the chem1cal cues that d1rect anadromous f1sh to the1r spawn1ng grounds. Th1s could cause add1t1onal losses of spawn1ng adults through or reduce the product1v1ty of spawn1ng areas through crowd1ng and redd super1mpos1t1on. Although the poss1b1l1ty also ex1sts that the populat1on of salmon w1ll 1ncrease 1n the McArthur R1ver, predat1on may also 1ncrease. If large mammals beg1n to concentrate 1n these h1gh dens1ty f1sh areas, sport and subs1stence hunt1ng pressure w1ll probably also 1ncrease. The maJor d1fference 1n these McArthur tunnel alter- nat1ves 1s that 1n Alternat1ve A, no water would be prov1ded 1n the upper reaches of the Chakachatna R1ver, wh1le 1n Alternat1ve B, some flow would be ma1nta1ned Alternat1ve A would l1kely result 1n a total loss of the populat1on of sockeye salmon wh1ch spawn upstream of Chakachamna Lake. The est1mated escapement of sockeye upstream of the lake was 41,000 f1sh dur1ng 1982. Th1s would also cause the loss of the1r contr1but1on (presently unknown) to the Cook Inlet f1sheryo In add1t1on, because no ma1ntenance flows would be prov1ded below the lake, the spawn1ng, rear1ng and m1grat1on of salmon and res1dent f1sh 1n the Chakachatna R1ver dra1nage would l1kely be s1gn1f1cantly and adversely affected. Est1mated escapement of salmon below the lake 7-16 I I l I ,~ I I ) ) I I J I I ~-_? ) I I I I I I I c J I I I I l I I ' I 0 \._ f I ~ r-'0 ' I I I ~~ 1s over 16,000 f1sh (Sect1on 6.8.3) wh1ch could be lost. In Alternat1ve A there 1s a s1gn1f1cant potent1al to drast1cally reduce the populat1ons of salmon wh1ch are represented by the est1mated escapement of over 57,000 salmon 1n the Chakachatna dra1nage. Alternat1ve A prov1des no f1sh passage to and from the lake. The sockeye salmon and Dolly Varden wh1ch spawn above the lake would not be able to ascend to the lake unless the lake level exceeded the present channel 1nvert (El. 1128) by at least 1 ft at the lake outlet. Down- stream m1grants could not pass from the lake unless the water was at th1s level or 1f they passed through an outlet structure wh1ch would prov1de the m1t1gat1ve flow. The 1mpact of thls alternat1ve w1thout prov1s1on for a f1sh passage structure could be substant1al Alternat1ve B would prov1de for year round flow releases to the Chakachatna R1ver (Table 7.2). The amounts of 1nstream flows selected are approx1mately 30 percent of the average annual flow dur1ng May through September and between approx1mately 10 percent of the average annual flow dur1ng the w1nter months, October through March. Aprll flows are 1ntermed1ate. These flow quant1t1es are very tentat1ve and the f1nal recommendat1ons regard1ng flows to be released to m1t1gate potent1al adverse 1mpacts w1ll be based on further stud1es to be performed 1n the future, and may be greater or less than the values presented here1n. The 1mplementat1on of Alternat1ve B should 1nfl1ct less adverse 1mpact on the f1sh wh1ch 7-17 Table 7.2 Natural and Alternat1ve B regulated mean monthly and mean annual flow at the Chakachamna Lake outlet. Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean Annual Flow Mean Monthly Flows Natural (cfs) 613 505 445 441 1,042 5,875 11,950 12,000 6,042 2,468 813 1,206 3,645 Regulateda (cfs) 365 343 345 536 1,094 1,094 1,094 1,094 1,094 365 365 360 679 a Regulated flows were est1rnated us1ng the Montana Method as descr1bed 1n Sect1on 6.2.2.1 7-18 II I I ! i _! 'l j ) ' I C-J I I I I I I I r \ I I I I~ I l 1 L__, I I I I I I Ll spawn and rear below the lake, than Alternat1ve A. The sever1ty of adverse effects upstream of the lake would depend on reservo1r operat1on and the m1t1gat1ve measures taken. Wh1le no spec1f1c des1gn concept was developed for f1sh passage fac1l1t1es that would perm1t f1sh to pass 1nto and out of the lake, an allowance was 1ncluded 1n the est1mates for the cost of one. The 1nfluence on the human resources w1ll probably also be less severe s1nce the commerc1al f1shery w1ll probably not be as heav1ly 1mpacted, but the 1mpact due to the loss of a port1on of the lake tr1butary spawn1ng could be substant1al. wh1le the 1mpacts related to Alternat1ve A affect1ng local resources would be d1ff1cult to m1t1gate and s1gn1f1cant changes 1n both the d1str1but1on and abundance of f1sh and w1ldl1fe populat1ons would almost certa1nly occur, the 1mpacts result1ng from Alternat1ve B would be less severe pr1mar1ly through the 1nstallat1on of f1sh passage structures and ma1ntenance of adequate downstream d1scharge. It should be noted, however, that wh1le not d1rectly stated, the loss of spawn1ng areas, and JUVenlle hab1tat due to any of the proJect alternat1ves w1ll most l1kely eventually man1fest 1tself as a decl1ne 1n the populat1on of adult f1sh as well. In add1t1on, s1nce eggs, fry, and JUVenlles of all spec1es prov1de food (prey) for other spec1es, losses of spawn1ng and nursery areas w1ll almost certa1nly result 1n eventual reduct1ons 1n the stand1ng crop of the1r predators. For example, losses of ]uven1le sockeye salmon 1n Chakachamna Lake would probably also result 1n an overall decl1ne 1n lake trout. 7-19 7.3.3 Potent~ally, one of the more substant~al ~nfluences to ~mportant floodpla~n r1par~an hab~tats and w~ldl~fe d~str~but~ons from the McArthur alternat~ves ~s the d~sposal of large quant~t~es of waste rock ~n the McArthur valley. W~thout proper s~te select~onv stockp~le des~gn, and eros~on controlv th~s d~sposal could s~gn~f~cantly alter valuable r~par~an hab~tats, and detr~mentally affect w1ldl1fe spec1es that rely upon these hab1tats. Moose, ptarm1ganv small mammals, and passer1ne b1rds would be most l1kely affected from substant1al floodpla1n hab1tat alterat1ons. Chakachatna Tunnel Alternat1ves C and D Through the 1mplementat1on of Alternat1ves c or D, the 1mpacts result1ng from log1st1cal support or construct1on act1v1t~es would be s1m~lar. However, s~nce all act~v~t~es are restr~cted to the Chakachatna flood-pla~n ~n these alternat~ves, the resources ~n the McArthur dra~nage w~ll not be affected Although ~mpacts on the w~ldl~fe populat1ons may occur, s~gn~f~cant 1mpacts w1ll occur to the f~sher1es. S1nce access to Chakachamna Lake w~ll be ~ncreased, sport and subs~stence f~sh~ng pressure may ~ncrease. W~th the road, camps~te and d~sposal s1te for rock excavated from the tunnel, all located 1n the Chakachatna canyon, an ~mportant v~sual resource w~ll be mod~f~ed. In add1t~on the presence and act1v~ty assoc1ated w~th these fac1l~t~es may ~mpede large mammal movements through the canyon temporar~ly dur~ng construct1on of the proJect Depend~ng upon fac1l1ty locat~ons and act~v~ty levels, large mammal movement patterns may also be affected dur~ng proJect operat1on. 7-20 ---., I I I J I j I I_ ( , I I I I I I ) I I I I I tj j I I I r 1 I ~ I I \ LJ ir I I 1_--' ( I I I I' I l ) Dur1ng the pre-operat1onal phases, the f1shery 1n the Chakachamna dra1nage w1ll probably only be 1mpacted to a small extent over a relat1vely short term. Above the powerhouse, the 1mpact on the Chakachatna R1ver and Chakachamna Lake f1shery w1ll be dependent on whether flows are ma1nta1ned and f1sh passage fac1l1t1es prov1ded. Alternat1ve C does not allow for these m1t1gat1ve measures. Therefore, the 1mpacts to the f1shery 1n or above the lake, and thus the w1ldl1fe and commerc1al f1shery 1n the surround1ng area w1ll be s1m1lar to that 1nfl1cted through Alternat1ve A. S1nce Alternat1ve D does prov1de flows (Table 7o3) and m1gratory passages, the 1mpacts would be s1m1lar to those descr1bed for Alternat1ve B 6 but w1th substant1ally less adverse 1mpact below the powerhouse due to the h1gher flows released by that fac1l1ty. W1th1n the proJect area, some resources w1ll be affected no matter wh1ch alternat1ve 1s chosen. Thls 1s partl- cularly true of sc1oeconom1c, land use, and transport- atlon character1st1cse Through the 1mplementat1on of m1t1gat1ve measures, 1t may be poss1ble to offset many of the adverse 1mpacts. However, the m1t1gat1on technn1ques outl1ned w1ll probably not restore the env1ronment to pre-operat1onal cond1t1on. 7-21 Table 7o3 Natural and Alternat~ve D regulated mean monthly and mean annual flows at the Chakachamna Lake outlet. r-tonth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean Annual Flow Mean Monthly Natural (cfs) 613 505 445 441 1,042 5,875 11,950 12,000 6,042 2,468 1,206 1,206 3,645 Flows Regulated a (cfs) 30 30 39 30 30 30 30 30 30 30 30 30 30 a Regulated flows were assumed to be suff~c~ent m~n~mum flows to ma~nta~n m~gratory passage as descr~bed ~n Sect~on 6.2a2.1. 7-22 :j I I (-I I I I ,_, I I I I ) ' J I I I I 'I I I L } r, I I L I il I I ~___) [l ( I L ( I \ I I l' r- 1 I I , I l I L) r I I I I I L~) ,, I I I L I ~--, I r I i '- Recommended McArthur Tunnel Alternat~ve E Th~s sect~on presents potent~al effects of an ~dent~f~cat~on of some the recommended proJect alternat~ve, Alternat~ve E. The ~dent~f~cat~on of effects ~s based upon data developed dur~ng the course of stud~es carr~ed out dur~ng 1981 and 1982. Th~s evaluat~on addresses the potent~al effects of proJect construct~on and operat~on on the aquat~cv w~ldl~fe and botan~cal resources of the s~te area. Evaluat~ons of potent~al effects on aquat~c hab~tats and aquat~c b~ota are based upon hydrolog~cal and f~sher~es stud~es conducted dur~ng 1981 and 1982. Evaluat~ons of potent~al proJect effects on terrestr~al b~ota are based on 1981 reconna~ssance data. The larger data base ava~lable on the hydrology and f~shery resources of the study area allowed a more deta~led exam~nat~on of potent~al effects on these resources. Potent~al Effects on Aquat~c B~ota Construct~on and operat~on of the proposed Chakachamna Hydroelectr~c ProJect w~ll result ~n changes to the aqua~~c hab~tat and a5soc~ated f~shery resources ~n the McArthur and Chakachatna R~vers, Lake Chakachamna, and tr~butar~es upstream of Lake Chakachamna, such as the Ch~ll~gan and Ig~tna R~vers. Th~s sect~on exam~nes potent~al effects of proJect Alternat~ve E on the aquat~c b~ota In th~s sect~on the term 11 ~mpact" refers to both d~rect and ~nd~rect effects on f~sh and aquat~c b~ota, ~nclud~ng the ut~l~zat~on of aquat~c hab~tats result~ng from proJect-~nduced changes ~n the phys~cal character~st~cs of the env~ronment. Impacts on the f1shery can be e1ther benef1c1al or adverse. 7-23 The descr~pt~on of ant~c~pated effects presented below 1s a gener~c ~dent~f~cat~on of changes to f1sh hab~tat and d~rect effects on the f~shery l1kely to occur dur~ng the construct~on and operat~on of th~s proJect. It 1s based on ava~lable basel~ne 1nformat1on on the b~ology of the f~shery resources found ~n the McArthur and Chakachatna systems, ~dent~f~cat~on of potent~al changes ~n phys~cal character~st~cs, and the effect of hab~tat alterat~ons from s~m~lar act~v~t~es as found ~n the l~terature I I I I t 7 3 4 1.1 Construct~on of the Chakachamna Hydroelectr1c ProJect 1 i and Related Fac~l1t~es The construct~on effects that could potent~ally result ~n changes to the f~shery resource fall 1nto three maJor areas of construct~on-related act~v~ty: o Effects of permanent or temporary alterat~ons to water bod~es (~.e., dewater~ng, alterat~on of flow reg1me, or alterat~on of channels), o Changes ~n water qual~ty assoc~at~d w~th alterat1ons to the water body, or w~th effluent d~scharges and hazardous mater1al sp~lls: and o D~rect effects of the construct1on act1v~ t~es (~e., use of chem~cals, no~se, heavy equ~pment operat~on, etc.). Alterat~on of Water Bod~es Few alterat1ons of water bod1es are eApected dur1ng the construct1on phase of the proJect. However, alterat~ons may be assoc1ated w~th the follow~ng construc~~on act1v1t1es~ 7-24 I I J l I I I I -I I I l I I I ~~ -I I I c_) I ~I I I LJ I I I ---, I I I I I~ j o Installat1on of br1dges or culverts for roads and r1ghts-of~way; o Re-rout1ng of runoff from camps and mater1als storage areas; and o Re-rout1ng of flow 1n areas of near-stream or 1n-stream construct1on Br1dges and/or culverts w1ll need to be 1nstalled to prov1de road access over streams and other waterways. Properly des1gned br1dges and culverts, 1nstalled so as to prevent perch1ng and h1gh water veloc1t1es should have few adverse 1mpacts on waterways Dur1ng construct1on or 1nstallat1on of the br1dges/culverts, some local 1ncreases 1n turb1d1 ty and local1zed d1sturbance would be expected, but these should be of relat1vely short durat1on Potent1al 1mpacts of temporary 1ncreases 1n turb1d1ty on aquat1c b1ota are d1scussed under water qual1ty (below). Alterat1on of waterbod1es result1ng fro~ the log1st1cal support act1v1t1es assoc1ated Wlth the Chakachamna Hydroelectr1c ProJect w1ll most l1kely be small 1n areal extent although the spec1f1c extent and potent1al for 1mpact w1ll be dependent upon the per1od of ~onstruct1on and the m1t1gat1ve measures used. Re-routlng of runoff from camps, mater1als storage areas and construct1on s1tes 1s expected to affect small areas, pr1mar1ly 1n the McArthur R1ver canyon The re-rout1ng lS expected to pr1mar1ly 1nvolve re-routlng of surface run-off, where s1lt and soluble mater1als would otherw1se be carr1ed 1nto the waterbody Some re-rout1ng of 1n-channel flows may be necessary to allow construct1on actlVltleS 1n certa1n 7-25 s1te areas~ Presently, there are 1nsuff1c1ent data to 1dent1fy the extent of these areas. For example, ~n the McArthur R1ver canyon 1n-channel re=rout1ng may be necessary to allow the construct1on of the powerhouse and ta1lrace, and d1sposal of tunnel1ng spo1ls. Such re-rout1ng should only affect a small area 1n the 1mmed1ate area of construct1on The result1ng 1rnpacts could 1nclude a potent1al loss of some spawn1ng and rear1ng hab1tat and some degradat1on of downstream hab1tats. The extent of th1s loss cannot be determ1ned at th1s t1me. The channel structure 1n th1s 1mmed1ate area does not appear to be very stable, and therefore the s1gn1f1cance of the loss 1s unclear. The re-rout1ng of flow 1n some construct1on and camp areas may be permanent. Changes In Water Qual1ty. There are a var1ety of water qual1 ty 1mpacts that could potent1ally occur dur1ng construct1on These generally 1nvolve the d1scharge of s1lt-laden waters from var1ous areas and effluents. Peters (1979) noted that under present env1ronmental leg1slat1on and by use of current eng1neer1ng pract1ces, most d1scharges can be m1t1gated, altogether. 1mpacts due to such 1f not el1m1nated S1l t-laden waters from collected run-off and from excavat1on of fac1l1t1es, could represent a cons1derable source of s1lt and turb1d1ty to the r1ver unless they are held 1n detent1on ponds before be1ng d1scharged. Spo1ls w1ll be d1sposed of or stored at the headwater area of the Chakachatna and McArthur R1 vers. Spo1l at the upper McArthur R1ver canyon w1ll result from tunnel1ng and powerhouse excavat1on. Much of th1s w1ll be used for construc- t1on of r1ver tra1n1ng works needed to protect the 7-26 I I I I I I I l _I I ( I I I ~) I I I l I I I I I i I I I l - I I I I (_I l I I l I _j I l I I I I I I_ I -I I I I l_l : I I I I ~ _j f I I LJ powerhouse ta~lrace channel from eros~on and damage by the r~ver. The d~sposal area for excess spo~l w~ll be located so as to avo~d s~gn~f~cant adverse effects. Spo~ls ~n the Chakachatna dra~nage would ~nclude mater~als removed from the sp~llway channel, gate shaft ehcavat~on, f~sh passage fac~l~t~es and tunnel excavat~on Some spo~l w~ll be used to construct the outlet structure d~ke, wh~le the excess w~ll be d~sposed of ~n locat~on yet to be determ~ned and selected so as to m~n~m~ze adverse env~ronmental ~mpact. D~sposal areas w~ll be d~ked, and run-off controlled to m~n~m~ze sed~ment d~scharge ~nto waterways. Sett- l~ng ponds w~ll be used for sed~mentat~on of suspended s~lts pr~or to d~scharge to reduce potent~al ~mpacts The pr~mary change ~n water qual~ty that may occur from construct~on ~s ~ncreased turb~d~ty Th~s may be produced by ~ncreased eros~on assoc~ated w~th d~sposal of tunnel spo~ls and construct~on act~v~t~es Tur- b~d~ty or~g~nat~ng from run-off and construct~on ~s often assoc~ated only w~th actual clear~ng act~v~t~es and ra~nfall events The ~ncreases ~n turb~d~ty ~n the Chakachatna d~sposal area would occur near max~mum lake levels (El 1140) Increases ~n turb~d~ty would vary w~th the type, extent and durat~on of construct~on act~v~ty, but would be expected to be local ~n nature and of relat~vely short durat~on Increased turb~d~ty can reduce v~s~b~l~ty and decrease the ab~l~ ty of s~ght-feed~ng f~sh ( e g. salmon~ds) to obta~n food (Hynes, 1966 and Pentlow, 1949) In add~ t~on, salmon~ds may avo~d spawn~ng ~n turb~d waters (Dehoney and Manc~n~, 1982), and many f~sh, part~cularly older l~fe-stages, may completely avo~d waters conta~n~ng h~gh turb~d~ ty However, the turb~d~ty ~ncreases ~n ma~nstem areas of the 7-27 Chakachatna and McArthur R1vers would be expected to have a lower potent1al for adverse effect on f1sh due to the naturally h1gh turb1d1ty levels found 1n these water bod1es. S1ltat1on (sed1mentat1on) 1s often assoc1ated w1th construct1on act1v1t1es. There 1s a cons1derable amount of l1terature deal1ng w1th the effects of s1ltat1on on aquat1c b1ota (Burns, 1970, Shaw and Maga, 1943, Ward and Stanford, 1979), part1cularly the effect of s1ltat1on on salmon1d spawn1ng and 1ncubat1on. A general conclus1on reached by a rev1ew of the l1terature (Dehoney and Manc1n1, 1982) 1s that s1ltat1on and turb1d1ty 1mpacts have the1r greatest adverse effects on eggs and larval f1sh. In general, s1ltat1on can cause a s1gn1f1cant loss of 1ncubat1ng eggs and pre-emergent fry 1n redds. Th1s 1s generally a result of 1nterference w1th water and oxygen exchange 1n redds Upwell1ng flow 1n affected areas mdy tend to reduce such 1mpacts by reduc1ng the amount of sed1ment wh1ch settles 1nto the redd. Release of suspended mater1als can also affect other water qual1ty parameters 1nclud1ng d1ssolved oxygen, BOD, trace metals, and pH (P1erce et al., 1970). The product1on of concrete for construct1on of the f1sh passage fac1l1ty and powerhouse may result 1n the product1on of concrete batch1ng waste. Peters (1979) po1nts out that the d1scharge of th1s wast:e, 1f untreated, could lead to detr1men~al effects on f1sh populat1ons and hab1tat. A part1cular problem w1th th1s waste 1~ 1ts h1gh pH (10+) and the need to neutral1ze 1 t (pH 7) pr1or to d1scharge. It 1s expected that th1s waste w1ll be treated as requ1red by the ant1c1pated proJect NPDES perm1t. 7-28 1 I \ ' I I I I I i I I I I I i I j I I I ) I I _} I ~~ I I I r~ , t I I I : I I I_' ~ -, I I I '._! I l_J - I : I I I I I I ~-I I I (_~ Dur1ng peak construct1on act1v1ty, fac1l1t1es to house workers w1ll be located pr1mar1ly 1n the McArthur floodpla1n. The hous1ng and supply storage area w1ll occupy 20 to 30 acres. Due to the presence of a large construct1on force 1n the area, san1tary waste w1ll need to be treated and d1scharged. The extent of treatment of san1tary waste, 1ts volume, and the po1nt of d1scharge w1ll control the extent of potent1al 1mpact. Wastewater effluents can affect BOD, and therefore the d1ssolved oxygen, pH, nutr1ents, trace metals, and buffer1ng capac1ty of the rece1v1ng water. Such eff~uents can ±hus a£fect the water gual1ty of the f1sh hab1tat (USEPA, 1976; AFS, 1979, Hynes, 1966). Hazardous mater1als may also be used dur1ng construct1on act1 v1 t1es of the pro] ect. Although hazardous mater1al sp1lls are generally of short durat1on, they may have severe 1mpacts depend1ng upon the substance sp1lled. A number of factors w1ll affect the sever1ty of a sp1ll on f1sh. o The tox1c1ty of the substance sp1lled, o The durat1on and frequency of the sp1ll, o The quant1ty sp1lled, o The f1sh spec1es present, o The f1sh l1fe stages present, o The season (t1me), 1n wh1ch the sp1ll occurred, and o l11t1gat1on and clean-up prov1s1ons. Any substance used around the s1te, or waste produced on-s1te, could potent1ally be sp1lled d1rectly 1nto a waterbody. In general l1qu1ds used 1n large quant1t1es and over greater areas, 1nclud1ng fuels dnd lubr1cat1ng o1ls, would be more l1kely to be 1nvolved 7-29 ln spllls. Dlesel Oll, for example, Wlll be used and stored ln large quantl tles on-sl te In general, spllls Wlll be most serlous lf they occur ln areas of hlgh blologlcal (e g , spawnlng) actlVlty and are not dlsslpated qulckly, or lf a large area lS affected As ln the case of slltatlon and turbldlty, the less moblle llfe stages are most llkely to be adversely affected, slnce older JUVenlle and adult flsh can usually leave an affected area Good englneerlng practlces, and a thorough splll control plan should greatly reduce the potentlal for such lmpacts Dlrect Constructlon ActlVltles. Dlrect constructlon actlvltles lnclude actlvltles that can be expected to occur throughout the constructlon of the proJect These actlvltles, for the most part, Wlll be conflned to speclflc areas Durlng constructlon, some of the flrst actlvltles to occur Wlll lnclude the constructlon of access roads, clearlng of constructlon areas, stockplllng of constructlon materlals and fuel, move~ent of heavy equlpment, and constructlon of support faclll tles ActlVltles assoclated wlth support faclllty constructlon Wlll lnclude cuttlng and clearlng ln areas near several streams The removal of ground cover durlng thls proJect Wlll be mlnor but may locally lncrease the potentlal for greater run-off, eroslon, lncreased turbldl ty and lncreased dlssolved sollds (Llkens et al , 1970, Boreman et al , 1970 and Plerce et al , 1970) The extent of lmpacts can be mlnlmlzed through the use of mltlgatlve practlces to control eroslon and related sedlmentatlon and turbldlty 7-30 I I ~~ I I J i I ! _j ~ I I_) I I I I ~~ I I I --, I \j 1---.1 I The removal of bank cover may locally 1ncrease the exposure of f1sh to terrestr1al predators and lead to a decrease 1n the1r populat1ons (Joyce et al, 1980). There are no plans for regular operat1ons of heavy mach1nery 1n streams. The pr1mary use of heavy mach1nery would be dur1ng the re-rout1ng of flow. The extent of potent1al 1mpacts due to s1ltat1on and turb1d1ty should be short-term and dependent upon the extent of mach1nery operat1on and the type of substrate 1n the streams affected (Burns 1970) o Smaller substrates tend to be more affected (Burns, 1970). However, 1f water veloc1t1es are suff1c1ently h1gh, the depos1t1on of suspended sed1ments may not occur locally, and the effects could be m1nor (Shaw and Maga, 1943). Current construct1on plans do not requ1re 1n-stream blast1ng. As part of the construct1on act1v1t1es, water w1ll be d1verted from the streams 1n the construct1on area to be used for dust control, dr1nk1ng water, f1re-f1ght1ng water, san1tary water, concrete batch1ng, and wet process1ng of gravel among other uses. The d1vers1ons w1ll probably be accompl1shed by pump1ng from local stream segments and 1ntakes w1ll be screened and des1gned to use very low veloc1t1es to avo1d f1sh 1mp1ngement and entra1nrnent. Operat1on of the camp~ w1ll also result 1n 1ncreased access to an area that has prev1ously exper1enced relat1vely llttle flsh1ng pressure. The area~ potent1ally affected would be those stretches of the McArthur R1ver and 1ts tr1butar1es that are eas1ly access1ble by foot from the camp. 7-31 7 3.4.1 2 Operat~on of the Chakachamna Hydroelectr~c ProJect and Related Fac~l~t~es Potent~al ~mpacts of the operat~on of the proJect (Alternat~ve E) are expected to occur to the aquat~c b~ota through. o Changes ~n aquat~c hab~tat, o D~rect effects on aquat~c b~ota, and o Effects on f~sh passage ~nto Chakachamna Lake. Effects are expected to vary between waterbod~es and can be evaluated separately for the follow~ng o Chakachamna Lake and tr~butar~es, o Chakachatna R~ver, and o McArthur R~ver. Hydrolog~cal alterat1ons are d~scussed f~rst, and are then followed by the effects of those alterat~ons on the aquat~c b~ota Chakachamna I.Jake and Tr~butar~es. Chakachamna Lake w~ll be affected by a 72 ft annual water level fluctuat~on dur~ng proposed proJect operat~on. The max~mum proposed reservo~r level of 1155 ft ~s near the max~mum h~stor~cal lake level; th~s level w~ll occur seasonally under post-proJect cond~t~ons. 1'-hn~mum reservo~r levels w~ll be approx~mately 45 ft below pre-proJect m~n~mum levels. Such a drawdown w~ll expose lake shorel~nc and stream deltas wh~ch are normally ~nundated. Lake levels w~ll vary ~n Chakachamna Lake and w~ll result ~n ~ncreased ~nundat1on of lakeshore and delta areas dur1ng h~gh reservo~r levels, dewater~ng of submerged shorel~ne would occur dur~ng per1ods of drawdown 7-32 I I 1 I I I ; I I I I I I I I ! I '~ I I I I '- i I I '~ I I I The proJect effects on the water qual~ty of Lake Chakachamna may ~nclude ~ncreased suspended sed~ment and turb~d~ty concentrat~ons near tr~butary mouths The potent~al sed~ment ~nflow from the tr~butar~es ~s d~scussed below The channel grad~ent of the Chakachamna Lake tr~butar~es w~ll be affected by the drawdown and fluctuat~on of the reservo~r level. Max~mum water levels w~ll cause ~nundat~on of the lower reaches of streams wh~ch are not normally affected, m~n~mum water levels w~ll expose the ent~re stream delta surface and the upper port~on of the steep delta front. Result~ng changes ~n stream grad~ent w~ll be progress~ve and sequent~al. These w~ll l~kely be s~m~lar at the mouths o± all tr~butar~es, but to d~fferent degrees The ant~c~pated changes due to seasonal m~n~mum reservo~r levels ~nclude 2 o Dewater~ng of over 7 m~ of delta area; o Increase ~n stream grad~ent and accompany~ng eros~on where the stream flows down the front of deltas, o Development of new deltas, 0 Eventual mouths to channel degradat~on at the near the lowest regulated level, and tr~butary reservo~r o Degradat~on upstream as far as ~s requ~red for the stream to reach equ~l~br~um between the streamflow reg~me dur~ng low reservo~r levels and the mater~als through wh~ch ~ t ~s flow~ng; poss~bly 7-33 result~ng ~n local~zed rap~ds dur~ng the low water per~od, ~f eros~on res~stant mater~als are reached. Max~mum reservo~r levels can cause depos~ t~on of stream-borne sed~ments ~n those reaches of stream affected by backwater from the reservo~r. Some of the depos~ ted sed~ments would l~kely be eroded as the reservo~r level drops through the w~nter. flows may remove the rest of the depos~ts. Break-up Accord~ng to the proposed reservo~r operat~on schedule, the reservo~r w~ll be at max~murn level dur~ng September and drawn down to lower levels over the w~nter w~th a m~n~murn level occurr~ng dur~ng Apr~l or Maye Hab~ tat Effects -The operat~on of the reservo~r / should have effects on the f~sh redr~ng hab~tat w~th~n the lake. Dur~ng open water, JUven~le sockeye, lake trout, round wh~tef~sh and Dolly Varden are found throughout the ldke w~th many f~sh found offshore along steep drop-offs and JUSt under the ~ce ~n w~nter. It ~s unclear what the effect of chang~ng water levels may have on w~nter water temperatures or hab~tat use, part~cularly near shore. At h~gh reservo~r levels (dur~ng October and November) lakeshore areas may be used as spawn~ng hab~~at by lake trout. After reservo~r levels drop, ~ncubat~ng eggs and fry may be exposed to freez~ng or dess~cat~on. Relat~vely ~mrnob~le 1nvertebrates wh~ch reproduce ~n shorel1ne areas may also be affected There are, presently, ~nsuff1c~ent data to assess the 1mpact of such effects on lake trout populat~ons and stand~ng crop of benth~c ~nvertebrates, although the effects could be substant~al. 7-34 I ~ I __ I I I I __) ~ I I I r 1 I I I 1 - I I I I I I I I I I I~ I I I - I, I I I I I c__) It I I 1 I Lake levels w~ll be near m~n~mum level at break-up, at wh~ch t~me the pr~nc~pal movement of f~sh cons~sts of emergent fry mov~ng from the~r tr~butdry rear~ng areas to the lake. It ~s not expected that the h~gh grad~ents to the lake w~ll adversely affect these m~grants Dur~ng the per~od ~n wh~ch sockeye salmon and Dolly Varden spawn ~n tr~butar~es above the lake, reservo~r levels w~ll be greater than pre-proJect lake levels. Th~s w~ll potent~ally result ~n lake water flood~ng down&tream areas of the Ch~ll~gan R~ver and the Ken~buna Lake/Shamrock Lake rap~ds The effect of the lake water on the ut~l~zat~on of the lower areas of the Ch~ll~gan R~ver ~s not presently known but there ~s some ev~dence (wh~ch follows) that th~s may not be an ~mportant effect. The area at the mouth of the r~ver conta~ned a low dens~ty of spawn~ng sockeye compared to areas further upstream. It was used extens~vely as a m~ll~ng area Dur~ng September 1982, lake water ~nundated the area w~thout apparent ~mpact on e~ther sockeye or Dolly Varden spawn~ng Adverse effects would be expected ~f flood~ng of the lower Ch~ll~gan R~ver resulted ~n ~ncreased s~ltat~on wh~ch could affect hatch~ng success (see Water Qual~ty, above). D~rect Effects -The lake-tap (or mult~ple lake-taps) w1.ll w~thdraw water at approx~mately El. 974. The submergence depth would vary between 109 ft and 181 ft. F~sh that are entra~ned ~nto the lake tap would be exposed to turb~ne passage at the powerhouse and most would be expected to be k~lled by the turb~nes, or dur~ng passage through the pressure 7-35 d~fferent~al between the depth of the lake-tap and the power plant. Juven~le sockeye and both JUven~le and adult lake trout, Dolly Varden, and round wh~tef~sh I I I I I IJ may be vulnerable. I I Hydroacoust~c observat~ons of f~sh d~str~but~on ~n the 1 lake have ~nd~cated that most f~sh were detected well above the depth of the lake tap. Dur~ng the w~nter, over 99 percent of f~sh were detected ~n the upper 50 ft of the water column. Dur~ng September, 1982 over 88 percent of the f~sh detected were ~n water at least 60 ft above the proposed lake-tap (at that t~me of year ~t would have been located at 181 ft) w~th no f~sh detected below 161 ft~ Thus, potent~al loss of f~sh due to the lake tap based upon current data would be relat~vely low However, add~t~onal seasonal ~nformat~on would be needed to quant~fy potent~al losses F~sh Passage Chakachamna Lake -Alternat~ve E ~ncludes a f~sh passage fac~l~ty wh~ch ~s des~gned to perm~t upstream m~grants to ascend from the Chakachatna R~ver to the lake and to allow downstream m~grants to pass from the lake to the Chakachatna R~vero The f~sh passage fac~l~t~es are descr~bed ~n Sect~on 3. 5. Deta~led des~gn of the f~sh passage fac~l~ty and ~ts hydraul~cs has not been completed. The upstream passage fac~l~ty cons~sts of a pool and we~r f~shway constructed ~n an underground fac~l~ty at the lake outlet, and ~s connected to the Chakachatna R~ver downstream of the fac~l~ty by a tunnel and smaller f~shway Downstream m~grants w~ll be passed through a wheel gate ~nto a st~ll~ng bas~n and from there ~nto a tunnel wh~ch connects w~th the Chakachatna R~ver downstream. A grate at the 7-36 I I I I I i I I I I I I I I I I I I I I I f I~ 1 I I I I I I I I L_ downstream end would prevent the entrance of upstream m~grants ~nto th~s fac~l~ty. The fac~l~ty ~s composed of components found ~n a var~ety of ex~st1ng f~sh passage fac~l~t1es. Presently, there are 1nsuff1c1ent data ava1lable to assess the potent1al effects of th1s fac1l1 ty on m1grat1ng f1sh 1n a quant1tat1ve manner. Sockeye salmon and Dolly Varden would be expected to use th1s fac1l1ty, as both have been observed to spawn above the lake Escapement est1mates of sockeye 1nd1cate that (based upon 1982 data), over 41,000 sockeye (poss1bly more depend1ng upon yearly var1at1on) would need to successfully pass through the fac1l1ty to m1grate upstream. S1nce the percentage of the run successfully reach1ng the Ch1ll1gan and Ig1tna R1vers 1s not known, the true extent of the sockeye salmon resource can only be est1mated. From 10 to more than 100 t1mes as many sockeye can be expected to m1grate downstream due to the normally h1gher product1on of young f1sh (Foerster 1968). A smaller number of downstream Dolly Varden would also be expected to pass through the fac1l1 ty. If the fac1l1ty works as planned the 1mpact to the sockeye run should be low. If the fac1l1ty d1d not successfully allow the m1grat1on of sockeye both upstream as adults and downstream as JUVen1les then some part of the est1mated adult spawn1ng populat1on would be expected to be lost, as well as a port1on of 1ts presently unknown contr1but1on to the Cook Inlet f1shery. As des1gn deta1ls are determ1ned, the f1sh passage fac1l1 t1es w1ll need to be re-assessed 1n a more deta1led fash1on. 7-37 The release of water from Chakacharnna Lake 1nto the McArthur system could potent1ally result 1n 1mpacts to f1sh wh1ch would normally spawn 1n Chakacharnna Lake and· tr1butar1es above 1t. Wh1le the "hom1ng" of salmon 1s not completely understood, the or1entat1on of upstream m1grants to olfactory cues or1g1nat1ng 1n natal streams has been cons1dered to be a pr1nc1pal factor (Hasler, 1971) F1sh enter1ng the system through the M1ddle R1ver should not be affected by the McArthur release F1sh enter1ng the system through I II I I : J the mouth of the McArthur R1ver may encounter 1 [ olfactory cues from flows enter1ng the McArthur R1ver at the confluence of the lower Chakachatna w1th the I 1 McArthur R1ver, from the confluence of the Noaukta Slough w1 th the McArthur R1ver, and from water d1scharged from the ta1lrace of the power plant located 1n the McArthur canyon. F1sh that entered the Chakachatna R1ver e1ther at the lower r1ver confluence, or the Noaukta Slough would be follow1ng what 1s hypothes1zed to be the present m1gratory pathway and would not be expected to be s1gn1f1cantly affected by the other power plant d1scharge; some delay due to confus1on may occur. There 1s a potent1al for some of the upstream m1grants to be attracted to the ta1lrace 1n the McArthur canyon. S1nce the f1sh could not m1grate further upstream 1nto Chakacharnna Lake, three bas1c scenar1os could develop. o The f1sh could back down the system unt1l they detect alternate olfactory cues (1.e., at the Noaukta Slough) and then m1grate up the Chakachatna R1ver, o The f1sh could m1ll 1n the ta1l race unt1l seAually matured and then back down the system unt1l alternate cues were detected, or 7-38 I I I I _,ll I I I -I I I I \ 1 I J J I ~ I r~ tl ~ I o The f~sh could spawn ~n the McArthur Canyon. The s~gn~f~cance of a delay ~n m~grat~on ~s not presently knowno However 0 the spawn~ng of large numbers of lake tr~butary or~g~n sockeye ~n the McArthur R~ver canyon area could result ~n low egg hatch~ng success due to h~gh dens~t~es of spawn~ng f~sh and result~ng redd super~mpos~t~on, the use of poor spawn~ng hab~tat, or females not spawn~ng (Bell 1980). In add~t~on, the rear~ng hab~tat ~n the McArthur canyon ~s probably less su~table for sockeye salmon than ~n Chakachamna Lake. Thus, ~f ~ncreased spawn~ng occurred 1n th~s area, rear~ng would probably be less successful. Chakachatna R~ver. Water releases w~ll be made to the Chakachatna R~ver below the f~sh passage fac~l~ty. The quant~ty of the actual releases ~s not presently known, and w~ll be based upon future stud~es. However, prel~m~nary release flows have been est~mated as a start~ng po~nt for analys~s (Table 7.4). Such flows const~tute a relat~vely small percentage of pre-proJect annual flow. Tr~butary ~nflow downstream from the lake contr~butes relat~vely small quant~t~es of flow compared w~th pre-proJect flows at the lake outlet. However, depend~ng upon the t~me of year, the tr~butary ~nflow may substant~ally ~ncrease post-proJect flows downstream of the release structure~ H~stor~cal low flows w~ll be substant~ally reduced by proJect operat~on dur~ng October through Marcho Ten percent of the average annual flow ~s cons~dered to be the m~n~mum for short-term surv~val of f~sh and other aquat~c organ~sms (Tennant, 1975)a However 0 ~n th~s system 0 post-proJect releases from January through Apr~l may be less than 10 percent but 7-39 Table 7.4 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean Annual Flow Natural and Alternat1ve and mean annual flow at outlet. Natural (cfs) 613 505 445 441 1,042 5,875 11,950 12,000 6v042 2,468 1,206 813 3,645 E regulated mean monthly the Chakachamna Lake Regulated (cfs) 365 357 358 582 1,094 1,094 1,094 1,094 1 .. 094 365 365 363 6 85 aRegulated flows were est1mated us1ng the Montana Method as descr1bed 1n Sect1on 6.2.2.1. 7-40 a I ~ I I I I \ ( I I ;r ,-~ l I, I J ~ I I ! I l I I I I I I I l \ \ I r ) ( I \ I __J I \ ~, I I I ' -- 1 ) ( ) I (\ I I I 1) ..., I ' I I I I I ' I I '--~ st1ll represent between 60 and 122 percent of pre-proJect average monthly flows, respect1vely Flood flows would be mod1f1ed 1n the regulated flow reg1me. Chakachatna R1ver flood flows would be smaller 1n magn1tude than past events, but would exh1b1t a greater var1at1on around a mean flood value due to the relat1vely small 1nfluence of Chakacharnna Lake on the post-proJect r1ver system. The seasonal d1str1but1on and hydrograph shape of the annual floods may sh1ft from the m1d-surnrner, long durat1on floods under the natural flow reg1me, toward a fall, short dura bon flood more typ1cal of bas1ns w1 thout the storage effects of lakes and glac1ers. The sed1mentat1on character1st1cs of the Chakachatna R1ver system w1ll change w1th the regulated flow reg1me. Sed1ment transport w1ll decrease 1n response to decreased flows. The conf1gurat1on of certa1n stream reaches would l1kely change as a result of the flow alterat1on assoc1ated w1th the proJect. The mounta1nous reaches on the Chakachatna R1ver would reta1n a s1ngle channel steep grad1ent cond1 t1on, although 1 t would be carry1ng less flow. Spl1t channel reaches would l1kely assume more of a meander1ng conf1gurat1on. The bra1ded reaches above Stra1ght Creek and 1n Noaukta Slough would l1kely become more stable and the flow would be carr1ed by fewer channels wh1ch are character1st1cs of a spl1t conf1gurat1on. The lower reaches of the Chakachatna and M1ddle R1vers would l1kely reta1n the1r mednder1ng conf1gurat1on. Ice format1on and breakup processes w1ll also l1kely be affected by the proJect. The evaluat1on of the 7-41 nature and extent of these effects requ1res further study. Ma1nstem Hab1 tats ~ The phys1cal effects of the proposed flow reduct1ons are descr1bed above The ma1nstem hab1tats appear to be currently used as m1gratory pathways, rear1ng areas for sub-adult and res1dent f1sh, and there appears to be a small amount of s1de channel spawn1ng assoc1ated w1 th areas of upwell1ng or slough flow Table 7 5 l1sts est1mated escapements of f1sh spec1es for water bod1es 1n the Chakachatna R1ver dra1nage, class1f1ed as to whether the waterbody 1s l1kely to be affected by the reduced ma1nstem flow. The tr1butary water bod1es are not expected to be s1gn1f1cantly affected by reduced flows. S1de channels 1n the Stra1ght Creek mouth area and at stat1on 17 are expected to be most affected Observat1ons dur1ng 1982 have 1nd1cated that these areas w1ll probably not be dewatered or perched. The observat1ons have 1nd1cated that turb1d ma1nstem overflow, wh1ch 1s present 1n these areas dur1ng I h1gher flows, would be absent W1thout the cover prov1ded by th1s turb1d flow, f1sh spawn1ng 1n these areas may be more vulnerable to predat1on. S1de channel spawn1ng 1n both areas represents less than 50 percent of observed spawn1ng at each s1te. Depth of water at entry po1nts to s1de channels at stat1on 17 would be expected to be shallow and may adversely affect f1sh entry. Based upon 1982 observat1ons, the m1ll1ng areas at Tr1butary Cl and at the mouth of the Chakachatna Canyon Sloughs would be s1gn1f1cantly less turb1d than at present. Th1s may also 1ncrease potent1al 7-42 I I I I I j I I I I '/ I I II I I 1 I I - I I I I v I 1 I I I I : I I I I I >I I I I I \ 'r' I I I I I l ~ I I I, _I Table 7 5 Spec1es Sockeye1 Salmon Ch1nook 2 Salmon P1nk 3 Salmon Chum 4 Salmon coho 5 --.1 Salmon I Dolly 6 .p. w Varden F1g 6 132 2 F1g 6 134 3 F1g 6 136 4 F1g 6 137 5 F1g 6 138 6 F1g 6 141 X = Used ao; ' I Est1mated escapement of 1mportant f1sh species 1n th~ Chakachatna R1ver system by waterbody class1fied by potPnt1al effects of decreased flow of watPr from Chakachamna LakP More POTFNTIALJY Affected Chakachatna Br1dge Straiqht Creek ~touth Side Channels and Sloughs 203 1,193 0 0 0 59 152 1,482 76 1,560 X and Sect1ons 6 8 3, 6 8 6 and Sect1ons 6 8 3, 6 8 6 and SPct1ons 6 8 3, 6 8 6 and Sect1ons 6 8 3, 6 8 6 and Sect1ons 6 8 3, 6 A 6 and SPct1on 6 8 6 6 c;pawn1ng areas AFFECTED WATERBODIES 1- 1- 1- 1- 1- LE'ss Affected Chakachatna Canyon Sloughs 392 0 279 121 608 X 5 5 5 5 5 Chakachatna Tr1butaq (C1) 238 0 0 165 183 X Ig1tna R1ver 2,781 0 0 0 0 X POTFNTIALLY NON-1\rFECTf"D llATERBODIES Chllllgan R1ver 38,576 0 0 0 0 X Stra1ght Creek 0 0 0 0 0 Stra1ght Creek Clearwater Tr1butary 254 1,422 7,9/5 0 172 X -_ _;r vulnerab1l1ty to 1ncreased predat1ono The extent of the potent1al 1ncrease 1n vulnerab1l1ty to predat1on of spawn1ng adults at these s1tes w1ll need to be assessed after more data are collected. There are a number of f1sh spec1es wh1ch use ma1nstem and s1de channel areas as rear1ng hab1tat The effect of decreased flow on the ava1lab1l1ty and su1tab1l1ty of th1s hab1tat can not be determ1ned at th1s t1me Wh1le decreased flow w1ll decrease the wetted per1meter and therefore the area of a stream, the decrease 1s not l1nearly proport1onal to the decrease 1n flow (Tennant, 197 5) Add1 t1onal sources of 1nflow, 1nclud1ng sloughs and tr1butar1es such as Stra1ght Creek, should result 1n somewhat 1ncreased flow downstream of the outlet structuree The add1t1onal water sources (Stra1ght Creek, var1ous sloughs, and unnamed tr1butar1es) w1ll reduce effects of the decrease 1n upstream releasese In areas where pre-proJect water veloc1t1es are too great to conta1n su1table rear1ng hab1tat, decreased veloc1t1es could potent1ally 1ncrease su1table hab1tat. Presently, there are 1nsuff1c1ent data to evaluate all expected change Decreased flows dur1ng w1nter may cause changes 1n the 1ce cond1t1ons and also result 1n decreased overw1nter1ng hab1tat The actual nature and extent of effects cannot be determ1ned from ava1lable data but a s1gn1f1cant decrease 1n ma1nstem overw1nter1ng hab1tat 1s l1kely dur1ng the early w1nter. Sloughs -Observat1ons made dur1ng March and October 1982 have 1nd1cated that flow 1n sloughs located 1n the Chakachatna R1ver canyon and at stat1on 17 appear ( 1-I I I I l1 '-' I U ,~ I : I "' I I J> I r, I I I I l I ll to be 1ndependent of r1ver flow. It 1s not expected 1 1 I I 7-44 ' I I ~II I ; I I I I I "-I ! I ~ I : I I I I I 1 ,_, I I that reduced flow ~n the r1ver w~ll have an adverse effect on these waterbod~es Th1s w~ll need to be conf~rrned through more deta~led study. The overw~nter~ng hab~ tat ~n sloughs should not be affected by reduced flow ~n the ma~nstem of the r~ver Downstream m~grants or~g~nat~ng ~n the Chakachatna dra~nage may requ~re h~gh seasonal break-up flows to tr~gger the~r m~grat~on, proposed post-proJect d~scharges may not be suff~c~ent to tr~gger th1s behav~or. However, post-proJect releases dur~ng Apr~l and May are greater than pre-proJect flows and depend~ng upon the t~m~ng of outm~grat~on may be suff~c~ent to tr1gger the downstream movement. Data collected dur~ng 1982 suggest that outm1grat~on of chum salmon and some sockeye occurs dur~ng late May and early June. Collect~ons made dur1ng the summer and fall and ~n the Sus~ tna dra~nage suggest downstream m~grat~on and smolt~f~cat~on of coho, ch~nook and sockeye salmon cont~nues throughout the summer and fall Some data ~n the l~terature ~nd~cates that sw1mm~ng act~v~ty, downstream m~grat~on, and smolt~f~cat~on of some spec~es may also be controlled by photoper~od (Lorz, 1973, God1n, 1980). If the outm~grat~on ~s photoper~od controlled, h1gh break-up flows would not necessar~ly be requ1red~ Overall, ava~lable data do not suggest that an adverse effect would be expected on st~mulat~on of downstream m~grat~on. McArthur R~ver. The McArthur R~ver w~ll rece~ve flows from the powerhouse rang~ng from a m~n~mum of approx~mately 4600 cfs ~n July to a max~mum of approx~mately 7500 cfs ~n December. Present flows ~n the upper McArthur R~ver near the powerhouse are 7-45 est1mated to average about 600 cfs 1n July and 30 cfs 1n December. Thus, flows 1n th1s upper sect1on w1ll be substant1ally 1ncreased by the operat1on of the ~proJect dur1ng the ent1re year. The relat1ve magn1tude of 1ncrease w1ll be less downstream of 1ts confluence w1th the Blockade Glac1er channels. Post-proJect summer flow 1n the McArthur R1ver downstream of 1ts confluence w1th the Noaukta Slough w1ll be less than pre-proJect cond1t1ons due to the substant1al decrease 1n flow through Noaukta Slough. Floods on the McArthur R1ver upstream of Noaukta Slough would be 1ncreased by the operat1on of the proJect The amount of 1ncrease w1ll be roughly equ1valent to the mod1f1cat1on of the base flows upon wh1ch the floods are super1mposed. That 1s, the I source of the flood waters rema1ns unchanged, but the flow 1n the McArthur R1ver as the flood beg1ns w1ll be greater" The relat1ve 1ncrease 1n flow would decrease 1n a downstream d1rect1on along the McArthur R1ver Below 1ts confluence w1th Noaukta Slough, the McArthur R1ver would l1kely exper1ence a reduced flood magn1tude Th1s 1s due to the decrease of 1nflow from Noaukta Slough dur1ng the summer as compared w1th the 1nflow under pre-proJect cond1t1ons. Noaukta Slough contr1butes a greater mean da1ly flow to the McArthur R1ver from m1d-June through rn1d-September under pre-proJect cond1t1ons than the max1mum that w1ll be' d1verted to the McArthur R1ver for power generat1on dur1ng proJect operat1on. I I f I I I I \ I I \ I I The upper McArthur R1ver w1ll exper1ence 1ncreased I sed1ment transport loads due to the larger d1scharges 1n the channel The upstream reaches w1ll l1kely scour the channel bed to reduce 1ts grad1ent In add1t1on, bank eros1on w1ll l1kely 1ncrease 1ts rate \ 7-46 ~r I (I J I (,.--' I I 1 I ' e J i ~\ I I I L I and areal extent as a result of the 1ncreased flowo Flood d1scharges 1n m1d-September 1982 caused bed scour and bank eros1on, and transported quant1 t1es of sed1ments along 1 ts channel 0 magn1tude of th1s short-durat1on event large The was approx1mately 50 percent greater than those expected on a da1ly bas1s under post-proJect cond1t1onso The 1ncreased post-proJect flows 1n the McArthur R1ver are not ant1c1pated to cause s1gn1f1cant changes 1n channel conf1gurat1on. However, some meander1ng reaches, espec1ally toward the upstream end, may assume spl1t channel character1st1cs Further analys1s 1s requ1red to ascerta1n the effects on channel conf1gurat1on, of the 1ncreased sed1ment transport 1nto the lower reaches of the McArthur R1ver The 1ce processes 1n the McArthur R1ver w1ll also l1kely be affected by the proJeCto Ice format1on may be reduced or poss1bly el1m1nated by the 1ncreased quant1ty and temperature of flow. Evaluat1on of these effects requ1res further study. Turb1d1 ty 1n the McArthur R1 ver canyon would be expected to 1ncrease dur1ng the w1nter months Pre-proJect w1nter flow 1n that area appears to be der1ved from upwell1ng and 1s clear. Water from the powerhouse ta1lrace would be expected to have a h1gher turb1d1ty as 1s normally found 1n Chakachamna Lake. Turb1d1ty 1n the lake var1es w1th depth dur1ng certa1n t1mes of the year but 1s generally s1m1lar to that measured nedr the powerhouse locat1on 1n the McArthur R1vero Below the McArthur Canyon, flow from the Blockade Glac1er channel 1s also turb1d and therefore 7-47 effects below the confluence of that channel should be m1n1mal Ma1nstem Hab1 tat -Ma1nstem areas of the McArthur R1ver appear to be used as m1gratory pathways for sub-adult and res1dent1al adult rear1ng 1 and for spawn1ng 1n the McArthur R1ver canyon Table 7 6 l1sts escapement est1mates of maJor spec1es that spawn 1n the McArthur R1ver dra1nage by waterbody. The only area 1n wh1ch spawn1ng hab1tat of these spec1es 1s l1kely to be affected 1s 1n the McArthur canyon All other l1sted areas are tr1butar1es Spawn1ng hab1tat 1n sloughs and s1de channels of the McArthur canyon occur upstream of the powerhouse ta1lrace It 1s unl1kely that these areas w1ll be s1gn1f1cantly affected. Based upon 1982 escapement est1mates 1 a relat1vely small percentage of spawn1ng salmon w1ll be vulnerable to changes 1n ma1nstem flow Some f1sh that normally spawn above Chakachamna Lake may be attracted to the powerhouse ta1lrace wh1ch may affect spawn1ng adults of McArthur or1g1n (see above) The red1str1but1on of substrate 1n the powerhouse area may also affect spawn1ng. Presently 1 there are 1nsuff1c1ent data to determ1ne 1f the effect would be benef1c1al or adverse to the ava1lab1l1ty of hab1tat to spawn1ng adults Eulachon spawn 1n the lower reaches of the McArthur R1ver ma1nstem 1 below the Noaukta Slough. Flow alterat1ons are not expected to affect spawn1ng of th1s spec1es because dur1ng the per1od of eulachon spawn1ng1 the cont1nued post-proJect McArthur R1ver 7-48 \ ' I I I I I (' I I ) l IJ Table 7 6 Estimate escapement of important fish spec1es in the McArthur River system by waterbody classif1ed by potent1al of 1ncreasPd flow of water POTENTIALLY AFFFCTED AREA <lpec1es McArthur Canyon <;tream 13X Stream 13U Sockeye 666 5 5,416 6 1,213 6 Salmon Chinook 07 452 7 1,633 7 Salmon P1nk 60 8 4,225 8 5,402 8 Salmon Chum 19 09 23 9 Salmon Coho 1,182 10 1,378 10 3:?10 Salmon Dolly Varden X X X X= Probable Spawn1ng areas 1 Based on 6 day stream l1fe Table 6 35, SPct1on 6 8 3 2 sased on count of l1ve and dead f1~h Table 6 34, Section 6 8 3 3 sased on 6 day ~tream life Table 6 36, SPct1on 6 8 3 4 sased on peak on total counts Table 6 37, Section 6 8 3 5 aa~Pd on 10 day stream life Table 6 38, Sect1on 6 8 3 6 F1g 6 132 7 F1g 6 34 8 Fig 6 36 9sased upon 10 day strean 11fP Table 6 37 10 BasPd upon 10 day stre:-aJll 11fP T,hle 6 38 POTENTTALLY NON-AFFfCTED AREAS Streal'1s Cr>mb1ned 12 1 12 2 12 3 1;1 4 27,636 6 22 7 10,0901'1 59 2,137 10 X y X X X 12 5 X and Noaukta Slough flows are expected to be s~rn~lar to pre-proJect flows Increased post-proJect flows-w~ll occur above the Noaukta Slough confluence on the McArthur R~ver. The lower post-proJect flows below the Noaukta Slough confluence dur~ng June through September should not have a s~gn~f~cant effect on f~sh passage. It ~s not clear at th~s t~me ~f the upstream m~grants above the slough w~ll even be exposed to s~gn~f~cantly h~gher veloc~t~es than they are exposed to by pre-proJect flows Th~s w~ll need to be assessed ~n the future. Pre-proJect water temperatures ~n the v~c~n~ty of the proposed powerhouse locat~on have a w~de d~urnal var~at~on dur~ng the open water season. The d~scharge of Chakachamna Lake water dur~ng operat~on would tend to stab~l~ze the temperatures Water temperatures at the proposed lake tap depth were as follows· March 2.l°C August 6.5°C September 6.2°C The temperature of d~scharged water should be fa~rly constant and should reduce d~urnal var~at~on and ma~nta~n temperatures closer to opt~mal ranges for spawn~ng and ~ncubat~on for many of the spec~es present (Bell, 1980). There are a number of f~sh spec~es wh~ch use rna~nstem hab~tats ~n the McArthur R~ver for rear~ng hab~tat. Presently, the effect of changes ~n the flow reg~me ~n d~fferent reaches of the r~ver at d~fferent t~mes of year cannot be determ~ned. Changes ~n wetted per~meter, depth and veloc~ty for d~fferent areas w~ll 7-50 r I II \ II I I, I' r I I I ./ I~ o I I I I I I I I t 1 ( 1-~J~ I I J I '--' I,""'\ {I I l J I ~) I ) C I ) 1 \ I'C"' ) I --- f I I j 4 -\ 'I I I \ ( I 1 I ,_) affect the overall total su1 table area for each spec1es and l1festageo Thus, su1table hab1tat may 1ncrease, decrease, or rema1n the same Th1s w1ll also need to be assessed Increased flmv 1n the McArthur canyon from the powerplant d1scharge may affect ava1lable overw1nter1ng hab1tat 1n the McArthur dra1nage. Data collected dur1ng 1982 1nd1cate that the McArthur canyon and areas below 1t (stat1on 13) may be used as overw1nter1ng areas Increased flow and depth may 1ncrease the overw1nter1ng area ava1lable Insuff1c1ent data are ava1lable to assess such changes Water d1scharged from the powerhouse w1ll probably be warmer than water of .HcArthur or1g1n, 2 1°C, as compared w1th 1 2°C, respect1vely, dur1ng March 1982 Th1s may result 1n greater metabol1c act1v1ty by f1sh and other aquat1c b1ota dur1ng the w1nter, and result 1n more rap1d 1ncubat1on and earl1er emergence t1mes for McArthur canyon f1sh Such emergence t1mes would be s1m1lar to those found 1n the Chakachatna R1ver It 1s unclear from present data whether th1s w1ll have an adverse effect Increased post-proJect turb1d1ty dur1ng the w1nter =/ months should not have a s1gn1f1cant adverse effect on f1sh 1n the McArthur Canyon. Turb1d1ty levels should be s1m1lar to those measured 1n th1s area dur1ng the spr1ng through fall, and 1t would be expected that f1sh are well adapted to them There may be a potent1al for the d1scharge of d1s- solved gases at levels greater than 100 percent of gas saturat1on at the powerhouse Water d1scharged at the 7-51 powerhouse, entra1ned at lake tap depths of more than 100 ft, w1ll undergo a pressure change of more than 3 atmospheres The change 1n pressure w1ll reduce the amount of gas that the water w1ll hold thus creat1ng the potent1al for supersaturat1on to occur Ev1dence of a potent1al for supersaturat1on was detected dur1ng sampl1ng 1n September 1982 If supersaturat1on occurs 1t could have adverse effects on f1sh 1n the 1mmed1ate area of the d1scharge unless m1t1gat1ve measures are taken (Merrell et al 1971, Blahm et al 1975, F1cke1sen and Schne1der, 1976, Bell, 1980). Sloughs -Some sloughs 1n the 1mmed1ate V1c1n1ty of the ta1lrace of the powerplant may become 1nundated and water veloc1t1es may 1ncrease These changes nay affect the su1tab1l1ty of these hab1tats The extent of such changes cannot be determ1ned at th1s t1ne Tr1butar1es -No s1gn1f1cant changes would be expected 1n McArthur R1ver tr1butar1es due to post-operat1onal flows based upon current data 7.3.4 1 3 Summary of Potent1al Effects Potent1al effects of the proposed proJect alternat1ve on the aquat1c b1ota w1ll vary depend1ng upon waterbody and locat1on Potent1al effects of construct1on are l1kely to be l1m1ted 1n extent and of short durat1on Effects may 1nclude o Local 1ncreases 1n turb1d1ty, unl1kely to affect f1sh s1gn1f1cantly due to already h1gh amb1ent levels, 7-52 I I I I \; I 't ( l \ I ' I tl r , I fi I I \ :1 J I I I I I I j I ,..\ II I I) I -I I I '-; \ I (} ~\ I I o Local 1ncreases 1n s1ltat1on and poss1ble degradat1on of some spawn1ng hab1tat, o Local clear1ng of banks w1 th some 1ncreases 1n water temperatures, o Re-rout1ng of flow w1th potent1al red1str1but1on or loss of ex1st1ng hab1tat; and o Potent1al sp1lls of mater1als, wh1ch although of br1ef durat1on may adversely affect b1ota. Operat1onal effects d1ffer accord1ng to the waterbody cons1dered 1nclude Potent1al changes 1n Chakachamna Lake o Potent1al loss of some lake trout spawn1ng area and fry, o Seasonal var1at1on 1n ava1lable rear1ng hab1tat, o Flood1ng of the downstream area of the Ch1ll1gan R1ver and some loss of spawn1ng hab1tdt through s1ltat1on, and o Potent1al f1sh loss through turb1ne passage The successful operat1on of the f1sh passage fac1l1ty w1ll be necessary for the cont1nuat1on ot the populat1on of sockeye salmon wh1ch spawns above Chakachamna Lake. Insuff1c1ent data are ava1lable to properly assess the operat1onal character1st1cs of the current des1gn Flow reduct1ons 1n the Chakachatna R1ver w1ll potent1ally have s1gn1f1cant effects on ma1nstem and 7-53 s~de channel hab~tats. There are ~nsuff~c~ent data to assess potent~al changes ~n the su~tab~l~ty of hab~tat and the net loss or ga~n of rear~ng hab~tat Some potent~al effects that can be ~dent~f~ed ~nclude -~ o Decrease ~n cover prov~ded by turb~d water ~n some s~de channel spawn~ng areas downstream of sloughs, ~ o Decrease ~n cover ~n some s~de channel m~ll~ng areas downstream of sloughs, o Potent~al changes ~n d~str~but~on of f ~sh w~ th changes ~n hab~tat, and o Potent~al loss of some overw~nter~ng hab~tat Potent~al effects of the ~ncreased water release ~n the McArthur R~ver ~nclude o Potent~al m~s-cue~ng, stray~ng, and/or delay of f~sh that normally spawn above Chakachamna Lake through the release of olfactory cues at the McArthur powerplant ta~lrace, o Potent~al loss of some spawn~ng hab~ tat ~n the McArthur R~ver canyon; o Potent~al hab~tat changes ~n upper reaches of the McArthur R~ver; the spec~f~c nature and extent of such changes cannot be determ~ned at th~s t~me, o Potent~al decrease ~n temperature var~at~on ~n the upper McArthur R~ver result~ng ~n more opt~mal temperatures for spawn~ng and ~ncubat~on of some spec~es, and 7-54 ~ I \, I I I f 1-0\ I I I l I I I I I I L 1/ I I I ~; I IJ II c\ I I I ' l) r~ I I I ~ ' ' I' l_' !_} 7.3 4.2 o Potent1al release of gas supersaturated water wh1ch could adversely affect f1sh 1n the 11nmed1ate v1c1n1ty of the ta1lrace. Potent1al Effects on Botan1cal Resources The development of a hydroelectr1c power proJect at Chakachamna Lake, w1ll result 1n changes 1n the d1str1but1on and spec1es compos1t1on of vegetat1ve commun1t1es. Based upon current des1gns for Alternat1ve E, these changes would occur over a relat1vely small port1on of the proJect area Changes that do occur may be benef1c1al or detr1mental to the b1ota depend1ng upon the type of changes as well as the locat1on, durat1on and magn1tude of change 7 3.4 2 1 D1rect Hab1tat Loss Construct1on of a rockf1ll dyke and f1sh passage fac1l1ty 1n the upper Chakachatna R1ver canyon and a powerhouse 1n the McArthur R1ver canyon w1ll necess1tate the removal of vegetat1on over a relat1vely small area. The powerhouse and f1sh passage fac1l1ty w1ll be pr1mar1ly underground, thus m1n1m1z1ng surface d1sturbance. The rockf1ll dyke w1ll be s1ted 1n the upper reach of the Chakachatna canyon where the floodpla1n 1s unvegetated and the canyon walls and glac1al mora1ne support S1tka alder and w1llow wh1ch are abundant throughout the proJect area The areal extent of vegetat1on removal dur1ng road, camp, a1rstr1p, and borrow p1t development 1s not yet known because the locat1on and s1ze of these fac1l1t1es have not been suff1c1ently def1ned. 7-55 7 3 4.2.2 Ind1rect Hab1tat Alterat1on The most notable changes 1n the d1str1but1on of vegetat1on w1ll l1kely occur 1n the lower McArthur R1ver and Chakachatna R1ver canyons. In the lower ~cArthur canyon, 1ncreased flows emanat1ng from the ta1lrace and the depos1 t1on of excavated mater1als w1th1n the floodpla1n near the powerhouse may reduce the extent of r1par1an vegetat1on In the Chakachatna I 1 canyon below the dyke, reduced flows may enable r1par1an vegetat1on to become establ1shed w1th1n what 1s now the act.Lve floodpla1n. In t1me, 1f these r1par1an th1ckets do expand, add1t1onal hab1tat for moose, songb1rds and furbearers may be prov1ded I D1sposal of mater1als excavated from the power tunnel I < and f1sh passage fac1l1ty w1ll be stockp1led 1n the floodpla1n above the dyke When the dyke 1s completed and the lake level ra1sed to an elevat1on of 1155 ft, th1s d1sposal area, as well as port1ons of the lake shore w1ll be flooded. In the area subJected to the annual fluctuat1ons of lake water levels, port1ons of the Nag1shlam1na, Ch1ll1gan and other smaller lake tr1butary deltas w1ll most l1kely real1ze a change 1n the1r vegetat1ve cover. Vegetat1on may recede due to 1nundat1on and shorel1ne destab1l1zat1on However, such changes are expected to 1nfluence only a small area s1nce under pre-proJect cond1t1ons, the lake level only occas1onally reaches elevat1ons at or near 1155 ft. Above the h1gh water level, the shore may also develop a d1fferent spec1es compos1t1on, one more representat1ve of early seral stages and wetter so1l cond1t1ons (Newburg and Malaher, 1972). The ant1c1pated changes 1n r1par1an and shorel1ne vegetat1on cannot be further ref1ned unt1l s1te-spec1f1c, f1e1d ver1f1ed, hab1tat maps have been prepared and the operat1ng reservo1r levels better def1ned. 7-56 I \' I 'I ', I r' , \ _' I' I I ' I I I c__J 1 l l 'I ~~ I I I I ~~ j ' I L (;-"~ l I \! I ' -- t" L ) ,, II~\ l I ( I J j l v It Downstream from the McArthur and Chakachatna canyons, the ~nfluence of altered flows, e~ther ~ncreased or decreased, on r~par~an vegetat~on w~ll depend upon the d~rect~on and magn~tude of channel m~grat~ons and the amount of floodpla1n area removed from the ~nfluence of flood events. Based upon current ~nformat~on, the McArthur R~ver channel above Noaukta Slough has been naturally m~grat~ng and some rechannel~ng has occurred 1n the slough under normal flow cond~t~ons Susta~ned h~gher flows ~n the upper McArthur R~ver may result ~n accelerat~ng th~s m~grat~on The extent of channel m~grat~on ~s also dependent upon floodpla~n substrate and bank compos~t~on Unt~l ~nformat~on ~s ava~lable on these parameters, the speed, d~rect~on, and magn~tude of m1grat~on ~n the upper NcArthur R1ver cannot be assessed The 1nfluence of reduced flows 1n the Chakachatna R~ver and Noaukta Slough may be to reduce the frequency and magn1tude of rechannel1ng 1n the slough and to remove port~ons of the now act1ve floodpla1n from the 1nfluence of flood events Based upon current ~nformat1on, 1t 1s not poss1ble at th1s t1me to est1mate the locat~on, extent or t~m1ng of revegetat1on The 1nfluence of w1nd or veh1cle-generated dust emanat~ng from cleared areas, roads, and borrow p1ts may 1nfluence the vegetat~ve commun1ty compos1t1on 1n the 1mmed~ate v1c1n~ty of these fac~l1t1es Accumulat~ons of dust may accelerate the rate at wh~ch snow melts (Drake, 1981) and affect the growth of , cottongrass and mosses (CRREL, 1980). The extent of vegetat~on changes due to accumulat~ons of dust w1ll be dependent upon the methods and level of effort exerted to reduce dust 7-57 Off-road use of veh~cles ~n the proJect area may affect vegetat~on depend~ng upon the type of veh~cle, the t~me of year, and so~l mo~sture cond~ t~ons (Sparrow et al, 1978). Currently, no pol~cy ex~sts to control or perm~t off-road use of the s~te To assess the ~nfluences on vegetat~on of construct~ng and ma~nta~n~ng a transm~ss~on l~ne, the vegetat~ve spec~es compos~ t~on, transm~ss~on l~ne des~gn, and construct~on and ma~ntenance techn~ques w~ll need to be establ~shed s~nce th~s ~nformat~on ~s not currently ava~lable, the effects of a transm~ss~on l~ne on vegetat~on cannot be evaluated. 7 3 4 2 3 Summary of Potent~al Effects Potent~al effects of the proposed proJect alternat~ve on the botan~cal resources w~ll vary depend~ng upon locat~on Small areas adJacent to proJect fac~l~t~es w~ll be ~nfluenced by the construct~on and operat~on of the proJect. Such ~nfluences may ~nclude o Increases ~n bank eros~on along the upper McArthur R~ver due to ~ncreased channel m~grat~on; o Increases ~n the extent of r~par~an vegetat~on ~n areas removed from the act~ve floodpla~n by reduced flows ~n the Chakachatna R~ver; o Altered d~str~but~ons of vegetat~on along the lake shore and deltas due to h~gher, fluctuat~ng lake levels, and o Reduct~ons ~n vegetat~ve cover and changes ~n spec~es compos~t~on ~n areas cleared for the roads, a~rstr~p, and borrow p~ts. 7-58 I r l \ I I I I 1/ ;~ \ I -- I / I I I 1 I I I ' r ~ ~J ' ~ ~ ' I I I I I (--'\ I r/ r'-4 1 () l li_l \' I I' (' L~ \'::>, I I I l I ll I I ~'--, 1 ~1 L.-0 I <~ I (I l~ A \~ I a ,it I I --· ,....._., I I L) -fJ ( r: LJ 7.3.4 3 Although 1t 1s l1kely that these vegetat1on changes w1ll occur, the extent of the change'1s less than that typ1cally assoc1ated w1th the development of a hydroelectr1c proJect. Th1s 1s because des1gns for th1s proJect have 1ncorporated a lake tap rather than a reservo1r and1 thus· o Cons1derably less vegetat1on needs to be cleared, o Effects of change 1n albedo should be negl1g1ble; o The 1nc1dence of f1re and vegetatlve dlsease should be reduced s1nce 1t w1ll not be necessary to stockp1le large amounts of cleared vegetat1on, and o The amount of w1nd-generated dust should be less s1nce a much smaller area w1ll be cleared Vegetat1on ln the proJect area has been dramat1cally changed through pr1or development. Roads prov1de unrestr1cted access to the lower port1ons of the area, extens1ve t1rnber harvest1ng has greatly reduced the vegetat1ve cover over a large area near the Chakachatna R1ver, and an underground plpellne has been Sl ted on the shore of Trad1ng Bay. It 1s unl1kely that the development of the Chakacharnna Lake hydroelectr1c proJect would 1nfluence vegetat1ve cornmunltles to the extent of these pr1or developments Potentlal Effects on W1ldl1fe Resources and Hab1tats The construct1on and operat1on of the Chakacharnna Lake Hydroelectr1c proJect w1ll affect the w1ldl1fe resources of the area. One means by wh1ch w1ldl1fe may be affected 1s through hab1tat loss due to Because the area actually occup1ed 7-59 by a fac1l1ty 1s usually small when compared to the total area encompassed by a part1cular hab1tat type, unless a fac1l1ty 1s s1ted w1th1n a spec1al use area (e.g. calv1ng, nest1ng, or molt1ng areas), the loss of a small amount of hab1tat 1s usually not cr1t1cal to the future v1ab1l1ty of a populat1on. A second means by wh1ch the b1olog1cal resources may be affected 1s through hab1tat alterat1on. In th1s case, some phase of development 1s usually respons1ble for alter1ng the phys1cal or vegetat1ve cond1t1ons Examples of th1s 1nclude the al terat1on of r1ver hydraul1cs, lake morphology, coastal sed1mentat1on, and b1olog1cal commun1ty dynam1cs. Often when such changes occur, the ex1st1ng w1ldl1fe resources respond w1th changes 1n spec1es compos1t1on, d1vers1ty, and d1str1but1on The th1rd type of hab1tat change may occur as a result of an 1nflux of support serv1ces. Typ1cally th1s equates to an 1ncrease 1n the local human populat1on, 1ncreases 1n traff1c levels (1nclud1ng a1r and ground), and 1ncreases 1n no1se These cond1t1ons may result 1n decreased use of adJacent areas by w1ldl1fe Regardless of wh1ch type of hab1tat change occurs, the response of w1ldl1fe w1ll vary w1th the t1me of year and the spec1es 1nvolved. If the hab1tat lost 1s of m1nor 1mportance and the extent 1s small, w1ldl1fe populat1ons may only abandon or d1scont1nue the1r use of the affected hab1tat wh1le rema1n1ng 1n the general V1C1n1ty. However, the effect on populat1on levels may be severe 1f hab1tats used for 1mportant l1fe funct1ons are rendered unusable by 1ntense act1v1ty, or large scale hab1tat loss or change. These 1mportant areas 1nclude the land and water used for 7-60 \ I I I r ) I I ~ ) .-' I L"- \ \ ( \ I ' I' I I j ) I ,-- 1 I lJ l \ breed1ng, nest1ng, calv1ng, stag1ng, w1nter1ng and denn1ng 7.3 4.3.1 D1rect hab1tat Loss Through development of the Chakachamna Hydroelect~1c ProJect, d1rect hab1tat losses due to fac1l1ty s1t1ng w1ll occur w1th construct1on of the dyke, d1sposal areas, powerhouse, f1sh passage fac1l1 ty, camps, roads, a1rstr1p, port and dock1ng fac1l1 t1es, and borrow p1ts The 1nfluence of th1s hab1tat loss on w1ldl1fe populat1ons should be negl1g1ble. The dyke w1ll be s1ted at the outlet of Chakachamna Lake, an area that rece1ves l1ttle use by b1rds and mammals The powerhouse and f1sh passage fac1l1 ty w1ll be located 1n the McArthur R1ver and Chakachatna R1ver canyons, respect1vely. Because these fac1l1t1es w1ll be pr1mar1ly underground, relat1vely small quant1t1es of surface hab1tat w1ll be lost. Although the exact s1ze and prec1se locat1on of the rema1n1ng fac1l1t1es have not been determ1ned, each w1ll occupy a relat1vely small amount of hab1tat 1n an area that 1s not cons1dered to be essent1al to any spec1es of b1rd or mammal It 1s assumed that development of d1sposal areas 1n both the McArthur and Chakachatna floodpla1ns w1ll result 1n the largest hab1tat loss, and greatest d1sturbance to b1rds and mammals 7 3.4 3.2 Ind1rect Hab1tat Alterat1on Chakachamna Lake. Hab1tat alterat1on and d1sturbance due to the construct1on and operat1on of the proJect could 1nfluence the d1str1but1on of some w1ldl1fe populat1ons. In the v1c1n1ty of the lake above the dyke, fluctuat1ng water levels may have several 1IDpl1cat1ons. As the lake level 1s lowered dur1ng the 7-61 w1nter, 1ce along the shore w1ll most l1kely fracture, eventually result1ng 1n a zone of broken 1ce that may prevent some large mammals from ventur1ng out onto the frozen lake surface. Moose, bears, wolves, and small mammals are the pr1mary 1nhab1tants of the lake shore dur1ng w1nter. However, the degree to wh1ch these mammals use the frozen lake surface w1ll need to be establ1shed. Dur1ng the 1ce-free per1od, a var1ety of b1rds and mammalo use the shore of the lake The h1gher, fluctuat1ng water level dur1ng th1s per1od may alter small areas of shorel1ne hab1tat but should not s1gn1f1cantly 1nfluence the overall use of the shore by these w1ldl1fe Chakachatna and McArthur R1ver Canyons Construct1on act1v1t1es occurr1ng 1n the Chakachatna R1ver and McArthur R1ver canyons may 1nfluence the apparently l1m1ted use of the canyons by mammals and b1rds. The canyons are used by eagles, bears, furbearers, moose, and passer1ne b1rds. Near the construct1on s1tes, 1ncreased levels of no1se from heavy equ1pment and blast1ng may d1scourage eaglesu moose and bears from us1ng adJacent areas (Roseneau et al., 1981, McCourt et al. , 19 7 4) • However, other mammals, 1nclud1ng furbearers and small b1rds appear to have a h1gher tolerance for human d1sturbance and may not substant1ally alter the1r d1str1but1ons (Penner, 1976, Clark and Cambell, 1977). Th1s 1nfluence of no1se and d1sturbance on w1ldl1fe populat1ons 1n the canyons should be l1m1ted to the construct1on per1od Chakachatna and McArthur R1ver Floodpla1ns. Below the canyons, w1ldl1fe act1v1ty 1s more abundant and d1verse. In these areas, a var1ety of w1ldl1fe spec1es could be 1nfluenced by construct1on act1v1t1es. Due to 1ncreased levels of no1se and 7-62 ) I l ( I ' I i I --! I I \_} -' 1 I I l \ \ (.___ \ I i I ~- d1sturbance, sens1t1ve spec1es such as moose, gr1zzly bears, gray wolves, eagles, and swans may d1scont1nue the1r use of the affected area (Roseneau et al , 1981, McCourt et al , 1974, Hampton, 1981). Other spec1es, 1nclud1ng coyotes, ducks, and other small b1rds, are more tolerant of d1sturbance and w1ll probably not alter the1r d1str1but1on (Penner, 1976, Gallop et al , 1974, Schwe1nsburg et al , 1974, Ferr1s, 1979) If avo1dance of a construct1on area occurred 1t would most l1kely be temporary w1th 1nd1v1duals return1ng to the area soon after no1se and act1v1ty levels subs1ded However, 1f areas used by w1ldl1fe for 1mportant l1fe funct1ons are abandoned, a decrease 1n the abundance of some local spec1es may be noted. To evaluate wh1ch spec1es may be affected and to what extent, 1t w1ll be necessary to establ1sh the use and- 1mportance of the Chakachatna and McArthur floodpla1ns to w1ldl1fe The alterat1on of hab1tat and w1ldl1fe d1str1but1ons below the canyons dur1ng the operat1on of the proJect may be ev1dent as a result of changes 1n the vegetat1on commun1t1es or as changes 1n the abundance or d1str1but1on of prey (part1cularly anadromous f1sh). Changes 1n the d1str1but1on of vegetat1on (as descr1bed under Potent1al Effects to Botan1cal Resources) w1ll probably not result 1n s1gn1f1cant changes 1n the d1str1but1on of w1ldl1fe populat1ons Channel m1grat1on along the upper McArthur R1ver and rechannel1ng 1n Noaukta Slough may erode relat1vely small areas of r1par1an vegetat1on. Th1s may d1splace a few 1nd1v1duals, but overall abundance of a w1ldl1fe populat1on 1n the proJect area should not be s1gn1f1cantly changed. L1kew1se, a small 1ncrease 1n the abundance of floodpla1n r1par1an vegetat1on along the Chakachatna R1ver w1ll probably not result 1n a 7-63 s1gn1f1cant change 1n w1ldl1fe spec1es d1vers1ty or abundance 1n th1s dra1nage The ant1c1pated changes may be more clearly def1ned by acqu1r1ng 1nformat1on on the extent of channel m1grat1on, revegetat1on, and the use of r1par1an areas for denn1ng, w1nter1ng, breed1ng, and calv1ng It 1s unl1kely that m1nor changes 1n anadroMous f1sh abundance and d1str1but1on (descr1bed 1n Sect1on 7 1) w1ll have a s1gn1f1cant effect on the d1str1but1on of e1ther b1rds or mammals. Several spec1es of w1ldl1fe feed on anadromous f1sh Although bears and eagles are the most v1s1ble, m1nk, harbor seals, and beluga whales also consume f1sh or1g1nat1ng 1n the Chakachatna or McArthur dra1nages The degree to wh1ch these spec1es w111 be affected can be evaluated by 1nvest1gat1ng the ant1c1pated changes 1n f1sh d1str1but1on or abundance and the rel1ance of w1ldl1fe on th1s resource (M1ller and McAll1ster, 1982) Based upon the ant1c1pated change 1n anadromous f1sh abundance and the opportun1st1c nature of the w1ldl1fe spec1es 1nvolved, no s1gn1f1cant change 1n the abundance or d1str1but1on of w1ldl1fe 1s currently expected to occur 1n e1 ther the Chakacha tna or McArthur dra1nage as a result of th1s proJect Increased access to the area w1ll affect w1ldl1fe populat1ons by two means, 1ncreased d1sturbance from construct1on act1v1t1es, and 1ncreased local hunt1ng (sport and subs1stence) pressure. By ut1l1z1ng the ex1st1ng road network for construct1on and operat1on 1n the Chakachatna dra1nage, only a sl1ght 1ncrease 1n veh1cle-related d1sturbance to w1ldl1fe should occur. However, through the construct1on and use of two road extens1ons to access the McArthur dra1nage and Chakachatna canyons, there w1ll l1kely be a short-term 7-64 \I I I I I ' I I I I ,~ I I I I \ J '- I 1---, I 1 l~ ~, I I I ~ j (( ' I I ~ I /1 I I ~-- I 1,----) fl I J r 'f I I -I I~ \ I L) reduct1on 1n the use of areas adJacent to these roads by spec1es that are sens1t1ve to traff1c, part1cularly moose, bears, wolves, eagles, 1981, McCourt et al., 1970, Elgmark, 1976, et al , Goddard, and swans (Roseneau 1974, Hampton, 1981, Carbyn, 1974). The extent of th1s 1nfluence w1ll depend upon the locat1on of moose w1nter1ng and calv1ng grounds, the locat1on of brown bear, black bear, wolf, and wolver1ne denn1ng s1tes, and the locat1on of swan and eagle nest1ng, brood rear1ng, and fall stag1ng areas Future stud1es w1ll be needed to 1dent1fy the locat1ons of these 1mportant hab1tats and to allow for more def1n1t1ve assessments. Whether local w1ldl1fe populat1ons are 1nfluenced by 1ncreased hunt1ng pressure w1ll depend upon the magn1tude of the hunt1ng 1ncrease and the level of road access allowed Currently no pol1cy affect1ng access of the proJect area has been outl1ned The 1nfluence on w1ldl1fe of construct1ng and ma1nta1n1ng a transm1ss1on l1ne and the l1kel1hood of b1rd coll1s1ons or electrocut1ons w1th the l1nes w1ll be dependent upon the spec1es 1nhab1 t1ng the area, transm1ss1on l1ne des1gn, and construct1on and ma1ntenance techn1ques Unt1l th1s 1nformat1on 1s ava1lable, these effects cannot be assessed 7 3.4.3.3 Summary of Potent1al Effects W1ldl1fe populat1ons w1th1n the proJect area may be 1nfluenced dur1ng the construct1on and operat1on of the fac1l1ty" The d1rect loss of hab1tat by fac1l1ty s1t1ng w1ll most l1kely not s1gn1f1cantly affect the abundance or d1str1but1on of any w1ldl1fe populat1on 7-65 Hab~tat alterat~on, however, may result ~n some m~nor I' changes wh~ch ~nclude the follow~ng o Reduced access for moose, wolves, bears, and car~bou to the frozen lake surface dur~ng the w~nter due to fractured ~ce along the shore, 0 Reduced ut~l~zat~on by sens~t~ve spec~es wolves, moose, bears, eagles, and swans) (such as of the areas near the construct~on s~tes, camps, and roads due to ~ncreased levels of no~se and d~sturbance, o Increased hunt~ng pressure on large mammals and b~rds allowed by the presence of road extens~ons to the Chakachatna canyon and McArthur dra~nage, and o Increased mortal~ty of b~rds due to coll~s~ons or electrocut~ons from transm~ss~on l~nes Although these changes are l~kely to occur, the magn~tude of the ~nfluences are less than those usually assoc~ated w~th the construct~on and operat~on of a hydroelectr~c fac~l~ty. Th~s ~s because des~gns for th~s proJect have ~ncorporated an underground powerhouse, and a lake tap rather than a reservo~r and thus 0 Potent~ally ~mportant hab~tat, ~nclud~ng large mammal m~grat~on routes, moose w~nter~ng and calv~ng areas, bear and furbearer denn~ng and feed~ng areas, and b~rd nest~ng areas do not have to be ~nundated to create a reservo~r, o The d~sturbance assoc~ated w~th clear~ng large expanses of land w~ll be absent, and 7-66 I ) I I I] J o Surface no1se and d1sturbance assoc1ated w1th the construct1on of a dam w1ll be s1gn1f1cantly reduced. W1ldl1fe d1str1but1ons w1th1n the proJect area have been 1nfluenced 1n the past by large scale t1mber harvest1ng, road construct1on, relat1vely h1gh levels of hunt1ng pressure, and the construct1on of an underground p1pel1ne on the shore of Trad1ng Bay It 1s unl1kely that the development of the Chakachamna Lake proJect would 1nfluence w1ldl1fe populat1ons to the extent of these pr1or developments 7-67 7.4 7.4.1 PrOJect R1sk Evaluat1on Development of the proJect would be attended by a number of r1sks assoc1ated w1th the phys1cal layout of the proJect structures and natural phenomena occurr1ng w1th1n and adJacent to the proJect area. Some of these could d1rectly 1mpact the cost of construct1ng the proJect wh1le others could e1ther 1mpa1r 1ts output or add to the cost of ma1nta1n1ng the des1gned energy generat1on and peak1ng capab1l1ty. Typ1cal among these aspects are the follow1ng PrOJect Layout Lake tapp1ng Tunnel al1gnment -rock cond1t1ons Underground powerhouse s1te Natural Phenomena Barr1er Glac1er Blockade Glac1er McArthur Glac1er Mt. Spurr, Volcano Lake Clark -Castle Mounta1n Fault Fault1ng 1n Chakachatna Valley Bru1n Bay Fault The above 1tems are treated 1nd1v1dually 1n the paragraphs that follow. Lake Tapp1ng At th1s stage of the proJect stud1es, 1t has been necessary to presume that a locat1on can be def1ned by explorat1on where the rock cond1t1ons w1ll be su1table 7-68 :1 I J ' ,~ r 'J :J J I \ I I ~ J I I J ,__I 7.4.2 for construct~ng the lake tapp~ng. Based on exam~nation of rock conditions above the lake water level, the above presumption seems to be reasonable but a significant amount of exploration will be required to define suitable rockG Furthermore, as far as It has been possible to ascertain from reviewing the technical press, the combination of diameter and depth needed for the Chakachamna Lake tapp~ng IS without precedent and considerable modification of the tentative arrangement, developed as shown for preliminary estimating purposes on Figure 3-4, may be necessary before an acceptable design concept IS reached. Specifically, the length of the final plug may need to be Increased or multiple smaller diameter open~ngs may be requ~red to penetrate from the underground excavations out Into the lake. The length of the chamber between the bottom of the Intake gate shaft and the lake may need to be Increased. Factors such as these cannot be finally determined until some design phase subsurface exploration has been performed. Tunnel Alignment Rock Conditions As set forth In Section 7G2.2, bedrock characteristics, as they may affect tunnelling conditions, have not been specifically studied within the scope of studies thus far completed. No geological mapping has been done along the proposed tunnel alignment. However, aerial observations of rock exposed along the tunnel alignment and In the walls of the Me Arthur canyon lead to the Indication that suitable tunnelling conditions should be encountered. This expectation needs to be qualified to the extent that the rock overlying about 25% of the length of the tunnel IS concealed by glacial ICe and Its surface features cannot be seen. The depth of rock cover and ruggedness 7-69 ~ I I I \ of terra1n over the tunnel al1gnment v1rtually rule out I ~ the pract1cab1l1ty of conduct1ng any subsurface explorat1ons at tunnel grade, except 1n the v1c1n1ty of the upstream and downstream ends. The depth of cover exceeds 3000 feet over about 40% of the tunnel length and 1t exceeds 2000 feet over about 66% of the length. (F1gure 3-3}. W1th such depths of cover, ground water under h1gh pressure could be encountered where the tunnel penetrates permeable f1ssures or water bear1ng JOlnts. Some dramat1c changes 1n rel1ef occur at several locat1ons along the tunnel al1gnment. These could g1ve r1se to the presence of troublesome stress concentrat1ons part1cularly, for example, where a deeply 1nc1sed U-shaped valley runs perpend1cularly to the maJor pr1nc1pal stress of the 1n-s1tu bedrock stress f1eld. Furthermore, due to the nearby presence of the Castle- Mounta1n-Lake Clark fault and the depth of cover over much of the tunnel al1gnment, there 1s the poss1b1l1ty that 1n-s1tu rock stresses may be h1gh and that rock I~ I l f bursts may be a factor to contend w1th dur1ng excavat1on i , of the tunnela H1gh pressure ground water and adverse rock cond1t1ons are factors wh1ch could add to the cost of construct1ng the power tunnel The great depth of rock cover prevents explorat1on at tunnel grade except near the two ends. In the absence of explorat1on over so much of the tunnel length, more water at h1gh pressure, and more h1ghly stressed rock than ant1c1pated, m1ght be encountered dur1ng construct1on of the tunnel, and 1n that case, the constructed cost could exceed the cost that was est1mated at the present stage of the 1nvest1gat1ons. 7-70 ,~ I ( \~ I 7.4.3 Underground Powerhouse S~te F~nal determination and conf~rmation of the locat~on of the underground powerhouse site should preferably awa1t des~gn level explorat~on, the construct~on of an exploratory ad1t and laboratory and ~n-s~tu measurement of the eng~neering propert~es of the rock. The walls of the McArthur canyon afford good rock exposures and allow a more mean1ngful assessment to be made of the rock qual1ty than any number of dr~ll holes. There 1s aga~n, however, the nearby presence of the Lake Clark-Castle Mounta~n fault and the poss~bil1ty that h1gh ~n-s1tu rock stresses may occur near the fault If so, rock bursts could occur dur~ng excavat1on of the powerhouse cavern and assoc1ated underground excavat~ons. Barr~er Glac1er Th~s 1s the glacier that conta1ns Chakachamna Lake and controls ~ts water level. It descends the southerly slopes of Mt. Spurr to the Chakachatna Valley, which ~t crosses, and thrusts aga~nst the steep face of the Chlgmit Mounta1ns that forms the south wall of the valley During the summer of 1981, the u.s Geolog~cal Survey conducted some measurements of Ice th~ckness In connect~on with an evaluation of the volcanic hazards posed by Mt. Spurr. Many of the field data are still In raw form, but ~n the floor of the Chakachatna Valley, the thickness of Ice In the Barrier 1 Glacier was believed to be In the order of 500-600 feet (Mayo, u.s.G s. Fairbanks, verbal commun~cation, 1982) • The depth of water In Chakachamna Lake 1s about 300 feet. 7-71 The natural outflow from the lake d1scharges v1a a channel eroded through the glac~al 1ce along 1ts contact w1th the mounta1n wall on the south s1de of the valley. The channel 1s armored w1th large boulders wh1ch are carr1ed along by the glac1al 1ce and are depos1ted 1n the channel as the 1ce melts. Over the years, the channel bed apparently aggrades, and the lake water level r1ses unt1l there develops a comb1nat1on of c1rcumstances that produces an outbreak flood wh1ch erodes the channel bed and lowers the lake water level. The last known event of th1s nature took place on or about August 11, 1971 The flood peak was est1mated to be 1n the order of 470,000 cfs and the lake level dropped about 14 feet. (Lamke 1972). Only unsubstant1ated reports and fragmentary ev1dence ex1st of prev1ous outbreak floods. It 1s, however, rather ev1dent that these would be cycl1c events hav1ng uncontrolled and 1ndeterm1nate per1ods, and that the lake outlet 1s 1n a state of chang1ng equ1l1br1um that among other th1ngs 1s strongly affected by the rate at wh1ch the Barr1er Glac1er advances towards the south valley wall, and the annual runoff from the watershed area d1scharg1ng 1nto the lake. No ev1dence of surg1ng has been reported 1n Barr1er Glac1er though Pothole and Harpoon Glac1ers, nearby to the north, have both been 1dent1f1ed as surg1ng glac1ers (Sect1on 5.2 1.5). Barr1er Glac1er has, however, gone through var1ous cycles of advance and retreat 1n recent t1me, and may reasonably be expected to cont1nue to do so 1n the future. The extent to wh1ch such cycles m1ght affect the lake level, and thus the amount of regulatory storage ava1lable for power generat1on, cannot be pred1cted w1th certa1nty. 7-72 7.4.5 Blockade Glac1er Th1s glac1er 1s fed by large snow f1elds h1gh on the southerly slopes of the Ch1gm1t Mounta1ns to the south of the McArthur canyono At about 1700 feet elevat1on, the glac1er spl1ts 1nto two forks, one flow1ng southwesterly and the other northeasterly towards the McArthur R1ver. The glac1er 1mpounds Blockade Lake beyond the term1nus of the soutwesterly lobe. As set forth 1n Sect1on 5 2.1.4 of th1s report, Blockade Lake 1s the source of outburst floods that d1scharge 1nto the McArthur R1ver. The present term1nal mora1ne of the northeasterly flow1ng lobe of Blockade Glac1er l1es w1th1n about 1-1/2 m1les of the mouth of the McArthur canyon. If the Blockade Glac1er were to advance dur1ng the l1fe of the proJect, 1t 1s conce1vable that the mora1nal mater1al could also advance toward the McArthur R1ver and cause the r1ver bed to aggrade downstream of the mouth of the canyon. Th1s could cause a r1se 1n ta1lwater level to occur at the power plant s1te w1th the extreme consequence be1ng a flood1ng of the powerhouse 1f a channel were not mechan1cally excavated through th1s mater1al As summar1zed 1n the clos1ng paragraphs of Sect1on 5 2.1.4 of th1s report, Blockade Glac1er 1 s recent h1story has clearly been one of recess1on, and 1t 1s bel1eved that 1t began to w1thdraw from 1ts most recent max1mum advance w1th1n the last few hundred years. At that max1mum advance, melt water from the glac1er J01ned the McArthur R1ver near the canyon mouth and outwash may have caused some aggradat1on of the r1ver bed 1n the lower reaches of the canyon. Surg1ng of the Blockade Glac1er 1s 7-73 7.4.6 7.4 7 cons~dered to be the most l1kely mechan1sm that could be expected to produce an advance of the glac1er that m1ght ~mpact on the proposed McArthur powerhouse s~te No ev1dence suggest1ve of recent surg1ng was, however, observed dur~ng the f1eld stud1es. The poss1b1l1ty that cl1matolog~cal changes and consequent changes 1n mass 1ce balance may tr1gger surg1ng of the Blockade Glac1er dur~ng the l1fe of the proJect 1s a remote poss1b1l1ty that cannot be forecast or evaluated w1th any degree of certa1nty. McArthur Glac1er The term1nus of th1s glac1er l1es 1n the McArthur canyon about 5 m~les upstream from the proposed powerhouse s~te. An advance of the glac1er over that d~stance would endanger the ta1lrace channel and portals of the ta1lrace tunnel and access tunnel to the underground powerhouse. Such an advance would, however, 1nvolve almost doubl1ng the ex1st~ng length of the glac1er and ~s, therefore, most unl~kely to occur. S1nce the Blockade and McArthur glac1ers are fed by adJacent snow f1elds, a change ~n snow supply needed to cause a f1ve m1le advance 1n the McArthur Glac1er would create an even greater problem due to advancement of the Blockade Glac1er. Mt. Spurr Volcano The summ1t of Mt. Spurr r1ses to elevat~on 11,070 feet above sea level and l1es about 7 m~les northeasterly from the outlet of Chakachamna Lake and 7-1/2 m1les from the proposed power ~ntake s1te. The 1ntake could be located 7-74 ,- further to tne west to 1ncrease 1ts d1stance from the volcano but th1s would 1ncrease the length and cost of the power tunnel, and also the d1ff1culty and cost of access to the 1ntake s1te along the prec1p1tous mounta1n slopes on the south s1de of the lake. Mt. Spurr 1 s last maJor erupt1on occurred on July 9, 1953. It eJected a large ash cloud wh1ch reached an alt1tude of approx1mately 70,000 feet, darkened Anchorage and depos1ted about 1/4 1nch of volcan1c ash on the c1ty (Juhle and Coulter 1955). The source of the erupt1on was reported to have been Crater Peak, a subs1d1ary vent at 7575 feet alt1tude on the southerly slopes of the volcano. The erupt1on tr1ggered a mud sl1de that dammed the Chakachatna R1ver about 6 m1les downstream from the outlet of Chakachamna Lake. The r1ver backed up nearly 5 m1les, overtopped the dam and has s1nce part1ally eroded 1ts way down through the debr1s. Abundant ev1dence ex1sts along the northerly slopes of the Chakachatna Valley of a long h1story of v1olent volcan1c act1v1ty. Large depos1ts of mud flow mater1als and pyroclast1c brecc1as occur for several m1les along 1ts length. Exam1nat1on of aer1al photographs taken 1n 1954, 1957 and 1978 suggest the poss1b1l1ty that some m1nor mud flows may have occurred on the slopes below Crater Peak s1nce the 1953 erupt1on. The u.s. Geolog1cal Survey undertook a l1m1ted m1cro-se1sm1c study of the Mt. Spurr area dur1ng the summer of 1982. The results have not yet been publ1shed but they are planned to be the subJect of a report scheduled to be released dur1ng 1983. 7-75 Mte Spurr ~s regarded by some volcanolog~sts to be s~rn~lar, ~n several respects, to Mt. St. Helens 1n the State of Wash1ngton whose May 18, 1980 erupt1on devastated a 200 square rn1le area. In the path of the rna~n blast, devastat1on of forest land was complete as far as 18 m1les from the cratero Present technology for pred~ct1ng volcan~c act~v~ty 1s l1rn~ted to the short term, and there ~s no way to forecast when Mt. Spurr w1ll next erupt, or whether 1t rn~ght erupt dur~ng the l1fe of the proJect. A catas- trophlc blast, such as occurred at Mt. St. Helens 1s a rare event but of course cannot be ruled out at Mt. Spurr. As d~scussed ~n Sect1on 5.2.2.2 of th1s report, the general d~rect1on of a future blast at Mt. Spurr 1s expected to be 1n the southeasterly quadrant, or d~rectly across and down the Chakachatna Valley. The proposed power 1ntake s1te on Chakacharnna Lake could be an area of ash depos1t~on. It could also be affected by a large landsl~de or rnudflow, or by hot blasts from pyroclast1c flows 1f such were to occur, and the ev1dence 1s that these have occurred 1n the past, part1cularly 1n the Chakachatna Valley. Wh~le future events s1rn~lar to the 1953 Crater Peak erupt1on would probably have l1ttle effect on the ab1l1ty of the power fac1l~t1es to cont1nue ~n operat1on, they could read1ly put the f1sh passage fac1l1t~es out of serv1ce. Another mud flow could darn the r1ver below Crater Peak thus caus~ng 1t to back up and flood the proposed structure at the downstream end of the f1sh passage fac1l1t~es. The reduced flow 1n the Chakachatna R~ver would not have the same eros1ve power to cut 1ts 7-76 way down through the debr1s dam and 1t could well become necessary to mechan1cally excavate a channel through the debr1s to lower the water level and return the f1sh passage fac1l1t1es 1nto operat1on. ~ catastroph1c event of the Mt. St. Helens type, 1f d1rected towards the lake outlet and 1ntake structure, could have very ser1ous consequences and poss1bly bury both the upstream and downstream ends of the f1sh passage fac1l1t1es, and the power 1ntake, beneath a mass1ve mud flow. The tremendous amounts of heat released by pyroclast1c ash flows could melt 1ce 1n the lower parts of the Barr1er Glac1er and 1nterfete w1th th~ glac1er's ab1l1ty to cont1nue to conta1n Chakachamna Lake. The powerhouse and assoc1ated structures 1n 1ts v1c1n1ty would probably not be s1gn1f1cantly affected by volcan1c act1v1ty at Mt. Spurr because they are sh1elded from the d1rect effects of a volcan1c blast by the h1gh mounta1ns between the Chakachatna and Mc~rthur Valleys. Depend1ng on w1nd d1rect1on at the t1me of the erupt1on, ash depos1t1on 1s probably the ma1n effect that would occur near the powerhouse s1te and th1s could lead to temporary 1nterrupt1ons 1n power supply. S1m1lar outages could be caused by ash accumulat1ng on transmlss1on l1ne 1nsulators Volcan1c events are r1sks that would be assoc1ated w1th development of the proJect. The probab1l1ty of maJor events occurr1ng dur1ng the proJect's l1fe 1s small, but the probab1l1ty or effects on the proJect cannot be pred1cted w1th certa1nty. 7-77 7.4.8 7.4.8.1 Se~sm~c R~sk The s~te l~es w~th~n a zone of h1gh se~sm~c r1sk. As set forth ~n Sect~on 5 3.3.3 of th1s report, potent1al se~sm1c sources wh1ch may affect the proJect s1te are the subduct~on zone, faults 1n the crustal se~sm1c zone and severe volcan~c act1v1ty. The Lake Clark-Castle Mounta1n fault (crustal source) and the megathrust segment of the subduct1on zone are cons1dered the most cr1t~cal w1th respect to peak ground accelerat1on and durat~on of strong shak1ng at the s1te. The max~mum probable or operat1ng bas1s earthquake for the s~te, def1ned as the earthquake that can reasonably be expected to occur dur1ng the l1fe of the proJect has not yet been def1ned. The probab1l1ty that the v1bratory ground mot1on of the operat1ng bas1s earthquake w1ll be exceeded dur1ng the l1fe of the proJect can be calculated by us1ng generally accepted techn1ques. Thus, the se~sm1c r1sks assoc~ated w~th the s1te can probably be subm1tted to more rat1onal r~sk analys~s than can the r~sks assoc~ated w~th glac1ology or volcan~sm, pr~nc1pally because much more data 1s ava~lable on the frequency of occurrence of se~sm1c events ~n the reg1on than 1s ava1lable on the frequency of s~gn~f1cant volcan1c events from Mt. Spurr or the frequency of aberrat~ons 1n glac~al act1v1ty at the s~te. Lake Clark -Castle Mounta~n Fault Th1s ~s a maJor reg1onal fault that has been traced for over 300 m1les. (Magoon et al 1976). It extends from 1ts northerly end near the Copper R~ver bas~n about 120 m~les to the northeast of Anchorage (F1gure 5-9) , to the 7-78 7.4.8.2 southerly end ~n the Lake Clark area. It crosses the McArthur Canyon at the canyon mouth where a prom~nent r~ft can be seen 1n the mounta1ns1de. The northerly parts of the Lake Clark-Castle Mounta1n fault have been extens1vely stud1ed and ev1dence of recent d1splacement has been documented near the Sus1tna Valley. Less 1s known about the southerly port1on of the fault but 1t 1s cons1dered to be capable of caus1ng a large earthquake and of exper1enc~ng s1gn1f1cant d1splacement dur1ng the l1fe of the ProJect. For th1s reason, and for reasons of 1mprovement 1n rock qual1ty w1th d1stance from the fault, the proposed powerhouse 1s shown as be1ng upstream from the mouth of the canyon, although th1s results 1n some head not be1ng developed. At least one cross~ng of the fault by the power trans- m1ss1on l1ne cannot be avo~ded, th1s w1ll be 1n the v1c1n1ty of the mouth of the McArthur Canyon. The powerhouse sw1tchyard also would be 1n th1s v1c1n1ty. Thus, some of the transm1ss1on towers and sw1tchyard structures would be subJected to very strong shak1ng 1n the event of a maJor earthquake on the fault near the McArthur Canyon Underground structures w1ll probably be less vulnerable to damage than surface structures. The structures can be des1gned to w1thstand the strongest lateral forces expected to occur, but 1t 1s not poss1ble to des1gn aga1nst s1gn1f1cant d1splacement 1n the foundat1on at any g1ven structure s1te. Consequently structures should not be located 1n the fault zone. Bru1n Bay Fault Th1s 1s one of the maJor reg1onal faults 1n Southern Alaska. In the v1c1n1ty of the proJect s1te, 1t 1s 7-79 7.4.9 7.5 1nferred to occur more or less parallel to the Cook Inlet coastl1ne about 20 m1les southeast of the mouth of the McArthur Canyon (F1gure 5-9) But, 1ts trace 1n that area 1s obscured by glac1al d1pos1ts and 1ts relatlon- sh1p to the Castle Mounta1n Fault 1s not known. Faults 1n Chakachatna Valley Four features wh1ch may be s1gn1f1cant to the ProJect have been 1dent1f1ed 1n the Chakachatna Valley (F1gure 5-9), and are d1scussed 1n Sect1on 5.3.3.3 of th1s report. Based on the 1981 geolog1c 1nvest1gat1ons wh1ch were l1m1ted to study of remote sens1ng 1magery and of aer1al (hel1copter) observat1ons, 1t was concluded that these features 1nclude faults wh1ch may offset Holocene depos1ts {less than about 2 m1ll1on years old); also, one of the features trends toward the s1te of the proposed power 1ntake structure. Further study of the ProJect should 1nclude evaluat1on of the age and extent of fault1ng wh1ch 1s related to these features, 1n order to better assess the potent1al for fault d1splacement at or near ProJect structures References Juhle, Werner and Coulter, Henry, 1955, The Mt. Spurr Erupt1on, July 9, 1953· Amer1can Geophys1cal Un1on, Transact1ons, Vol.36, Number 2, Pages 199-202. Lamke, Robert D., 1972, Floods of the Summer of 1971 1n South-Central Alaska· u.s. Geolog1cal Survey Open F1le Report. Magoon, L.B., Adk1son, W.L., and Egbert, R.M. 1976, USGS Map No. 1-1019 Show1ng Geology, W1ldcat Wells, Tert1ary Plant Foss1l Local1t1es, K-Ar, Age Dates and Petroleum Operat1ons, Cook Inlet Area, Alaska. 7-80 CONSTRUCT ION COSTS AND SCHEDULES 8 0 CONSTRUCTION COSTS AND SCHEDULES 8 1 Est1mates of Cost Est1mates of construct1on costs have been prepared for the follow1ng alternat1ves for proJect development Alternat1ve A -400 MW McArthur tunnel development Alternat1ve B -330 MW McArthur tunnel development Alternat1ve C & D -300 MW Chakachatna tunnel development Alternat1ve E -330 MW McArthur tunnel development The est1mates are based on schedules of quant1t1es of mater1als and equ1pment needed for the maJor features of each alternat1ve to the extent perm1tted by the draw1ngs for Sect1on 3~0 of th1s report. In some cases, quant1t1es were proport1oned from the construct1on records of other proJects bear1ng s1gn1f1cant s1m1lar1ty of structures and cond1t1ons expected to be encountered dur1ng construct1on of the Chakachamna Hydroelectrlc ProJect. Un1t pr1ces developed for th1s and other proJects 1nvolv1ng s1m1lar types of construct1on and from analyses of b1ds rece1ved for the construct1on of s1m1lar types of proJects 1n Alaska, adJusted as necessary to reflect January 1982 pr1ce levels, were then appl1ed to the schedules of quant1t1es to arr1ve at the est1mated costs set forth 1n the Conceptual Est1mate Summar1es, sheets 1 of 2 and 2 of 2 The summar1es show the 8-1 CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL ESTIMATE SUMMARIES-SHEET 1 OF 2 ALTERNATIVES A LAND AND LAND RIGHTS Not mcluded 0 POWER PLANT STRUCTURE AND IMPROVEMENTS Valve Chamber 5,600 Underground Power House 26,200 Bus Gallenes 200 Transformer Gallery 4600 Valve Chamber and Transformer 400 Gallery -Access Tunnel P H Access Tunnel 13500 Cable Way 800 --51300 RESERVOIR DAM AND WATERWAYS Reservoir 100 Intake Structure 10400 Intake Gate Shaft 13 200 F1sh Fae1ht1es - D1ke & Spillway - Access Tunnel -At Intake 21,600 -At Surge Chamber No 3 6600 -At M1le 3, 5, No 1 0 -At M1le 7, 5, No 2 0 Power Tunnel 626,800 Surge Chamber -Upper 12900 Penstock-Inclined Sect1on 18 000 -Honzontal Sect1on and Elbow 6,700 -Wye Branches to Valve Chamber 13,200 -Between Valve Chamber & Power House 800 Draft Tube Tunnels 1,900 Surge Chamber -Tailrace 2,400 Tailrace Tunnel and Structure 10,300 Tailrace Channel 900 R1ver Trammg Works 500 Miscellaneous Mechamcel and Electncal 7,100 --753 400 A B -McArthur development h1gh level tunnel excavated by dnlhng and blastmg C D -Chacackatna valley development excavated by dnlhng and blastmg E -Me Arthur development low level tunnel excavated by bormg machma I I ( __ I I I _ _) I~J ESTIMATED COSTS IN THOUSANDS OF DOLLARS B c D Not mcluded 0 Not mcluded 0 Not mcluded 0 5,500 5,600 5 600 25 200 26 200 26,200 200 200 200 4,300 4300 4,300 400 400 400 13,500 13,500 13,500 800 800 800 ---49,900 51 000 51000 100 100 100 9,300 10400 10400 12,400 13 200 13 200 --- --- 19100 21600 21,600 5,900 8 900 8900 0 20,800 20,800 0 14,500 14500 580 400 ir12 500 712,500 11,000 12,900 12,900 16 500 15,400 15,400 6000 6700 6,700 11 900 12100 12,100 600 800 800 1,700 1,900 1,900 2400 2400 2,400 9,600 10,300 10300 700 900 900 500 500 500 6,100 5,700 5700 --694200 --871,600 --871 600 ~~-J E Not mcluded 5,500 25,200 200 4300 400 13500 800 49900 100 9,300 17,600 85,400 9,100 0 5 900 0 0 447,800 18 900 0 6 000 11,900 600 1,700 2,400 9,600 700 500 6,100 --633,600 --1 00 w ~ I l __ l CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL ESTIMATE SUMMARIES-SHEET 2 OF 2 ~I ESTIMATED COSTS IN THOUSANDS OF DOLLARS ALTERNATIVES A TURBINES AND GENERATORS 67 900 ACCESSORY ELECTRICAL EQUIPMENT 11,200 MISCELLANEOUS POWER PLANT EQUIPMENT 8 600 SWITCHYARD STRUCTURES 3600 SWITCHYARD EQUIPMENT 13,800 COMM SUPV CONTROL EQUIPMENT 1600 TRANSPORTATION FACILITIES Port 4600 A1rport 2000 Access and Construction Roads 59600 --66,200 TRANSMISSION LINE & CABLE CROSSING 63,200 TOTAL SPECIFIC CONSTRUCTION COST AT 1 040 800 JANUARY 1982 PRICE LEVELS ENGINEERING & CONSTRUCTION MANAGEMENT 124 900 SUBTOTAL 1,165 700 CONTINGENCY@ 20% 233,100 ESCALATION Not lncl INTEREST DURING CONST @ 3% PER ANNUM 111,900 OWNER'S COSTS Not lncl ALLOWANCE FOR FISH PASSAGE FACILITIES - TOTAL PROJECT COST AT 1510,700 JANUARY, 1982 PRICE LEVELS USE 1500 000 A B -McArthur development high level tunnel excavated by dnlhng and blastmg C D -Chacackatna valley development excavated by dnlhng and blastmg E -Me Arthur development low level tunnel excavated by bormg mach me 4,600 2 000 59,600 I B c D 57 900 54500 54,500 9,500 9000 9,000 7,300 6900 6900 3600 3600 3 600 12,500 12100 12,100 1,600 1,600 1600 4600 4,600 2,000 2,000 44100 44100 66 200 --50,700 50700 63 200 56500 56,500 965,900 1117500 1117,500 115 900 134,100 134,100 1 081,800 1,251,600 1 251,600 216 400 250 300 250300 Not lncl Not lncl Not lncl 104100 101,400 101,400 Not lncl Not lncl Not lncl 50000 -50,000 1 452,300 1,603 300 1 653 300 1,450 000 1,600,000 1,650 000 E 57900 9500 7 300 3,600 12,500 1,600 4600 2,000 59600 --66,200 63,200 905,300 108,700 1,014,000 203,000 Not lncl 97,400 Not lncl Under ReservOir Item 1,314,400 1,314 000 ) follow1ng est1mated proJect costs exclud1ng owner's costs and escalat1on Alternat1ve A $1 5 b1ll1on Alternat1ve B $1 45 b1ll1on Alternat1ve c $1.6 b1ll1on Alternat1ve D $1.65 b1ll1on Alternat1ve E $1 32 b1ll1on The above costs 1nclude a 20% cont1ngency added to the spec1f1c construct1on cost plus eng1neer1ng and construct1on management, and 1nterest dur1ng construct1on. The costs for Alternat1ves B and D add1t1onally 1nclude a prov1s1onal allowance of $50 m1ll1on for f1sh passage fac1l1t1es at the lake outlet. Costs for Alternat1ve E 1nclude a constant grade tunnel from powerhouse level at the McArthur R1ver to the base of the 1ntake gate shaft at Chakachamna Lake, and pend1ng the complet1on of geolog1cal stud1es of the tunnel al1gnment, the assumpt1on 1s made that th1s tunnel w1ll be dr1ven by a bor1ng mach1ne. Included also 1n Alternat1ve E 1s the est1mated cost of proposed f1sh fac1l1t1es at the Chakachamna Lake outlet as descr1bed elsewhere 1n th1s report and shown on draw1ngs The est1mated proJect costs are cons1dered to be conservat1ve because of the conservat1ve assumpt1ons made regard1ng the amount of rock support requ1red 1n the underground excavat1ons. For all of the alternat1ves, the pr1nc1pal structures cons1st of the follow1ng o Intake structure at Chakachamna Lake w1th underwater lake tapp1ng 1 and control gate shaft 8-4 I I - I I p I I I I I I I I 1 I I I I I I~ 1 : I I I I I I I I I I I I I~ I r I I I I I ~J I I I 0 0 Concrete l1ned power tunnel w1th construct1on access ad1ts. Surge chamber and except for Alternat1ve E, emergency closure gates at the downstream end of the power tunnel. o Underground concrete l1ned pressure penstock and man1fold o Concrete and steel l1ned penstock branches lead1ng to a valve chamber and the turb1nes. 0 0 Four un1t underground powerhouse w1th exploratory ad1t (to become the vent1lat1on tunnel) and ma1n access tunnel Underground transformer vaults and hlgh voltage cable gallery. o Ta1lrace tunnel and surge chamber 0 Ta1lrace outlet channel and r1ver protect1on works. o H1gh voltage cable term1nals and sw1tchyard o Transm1ss1on l1nes to northerly shore of Kn1k Arm. 0 H1gh Voltage submar1ne cable cross1ng of Kn1k Arm. In add1t1on, for Alternat1ve E the follow1ng pr1nc1pal structures are 1ncluded 8-5 8.1.1 o Concrete l1ned surge shaft connect1ng surge chamber and downstream end of power tunnel. 0 Rockf1ll d1ke at Chakachamna Lake outlete 0 Sp1llway at lake outlete o F1sh passage fac1l1t1es at lake outlet for both upstream and downstream m1grants. Power Tunnel The cost of construct1ng the power tunnel 1s the dom1nant feature, represent1ng more than half the est1mated cost of construct1ng each alternat1ve. Deta1led evaluat1ons were made of all operat1ons and the d1rect costs cons1dered necessary to construct the 25-foot d1ameter concrete l1ned power tunnel for Alternat1ves A, C and D, us1ng both rubber t1red and ra1l haulage equ1pment. The d1fference 1n cost between the two was found to be small. Thus, the cho1ce of haulage equ1pment w1ll probably be determ1ned by other cons1derat1ons such as for example, whether excavat1on and concrete placement would be scheduled by a Contractor to take place concurrently 1n a g1ven tunnel head1ng Th1s can be accompl1shed 1f necessary 1n a 25-foot d1ameter tunnel w1th e1ther ra1l haulage or rubber t1red equ1pment. The est1mated cost of construct1ng the 23-foot d1ameter tunnel requ1red for Alternat1ve B was f1rst proport1oned from the est1mated un1t costs per l1neal foot for construct1ng the 25-foot d1ameter tunnels for Alternat1ves A, C and D us1ng the same construct1on 8-6 I I I I I I I I I I I I I I r I, I I I~ I I I I I I I I I I I I I 'I I I methods of dr~ll~ng and blast~ng These costs are ~nd~cated ~n the summary schedule for Alternat~ve B at tne end of th~s chapter as $580,400,000 For Alternat~ve E, an alternat~ve method of dr~v~ng the tunnel by a bor~ng mach~ne was cons~dered as well as a mod~f~cat~on of the prof~le of the tunnel us~ng un~form grade from near the base of the ~ntake shaft to the powerhouse. Two surface samples of rock collected from the general v~c~n~ty of the power ~ntake s~te at Chakachamna Lake and one sample collected from the surface ~n the v~c~n~ty of the powerhouse s~te near the McArthur R~ver were tested for compress~ve strength, ~ndentat~on, po~nt load, quartz content and cutter penetrat~on rate at The Robb~ns company laboratory ~n Kent, wash~ngton. Although test data obta~ned from surface samples can somet~mes be m~slead~ng when compared to comparable data obta~ned from fresh rock samples taken at depth, the data were used w~th appropr~ate conservat~sm to est~mate the rate of penetrat~on of a tunnel bor~ng mach~ne work~ng ~n th~s rock The use of a bor~ng mach~ne for excavat~ng showed a sav~ng ~n costs of $126,700,000 Chang~ng the grade of the tunnel showed an add~t~onal sav~ng of $5,000,000. The total cost of construct~ng the tunnel was thus reduced from $580,400,000 to $448,700,000 Th~s cost was used ~n the summary schedule for Alternat~ve E, the recommended alternat~ve. Tne est~mated tunnel construct~on costs are based on the follow~ng ~terns 8-7 0 Excavat1on for Alternat1ves A, B, C and D would be by convent1onal dr1ll1ng and blast1ng generally w1th full face excavat1on, dr1ll1ng 12-foot depth rounds. Allowance 1s 1ncluded for a nom1nal length of tunnel where the depth of rounds m1ght have to be reduced, or where top head1ng and bench techn1gues m1ght have to be used temporar1ly, 1f less favorable ground cond1t1ons are encountered. o Excavat1on for Alternat1ve E would be by a bor1ng mach1ne to 27-foot bor1ng d1ameter wh1ch after l1n1ng would be hydraul1cally equ1valent to the 23-foot d1ameter horseshoe for Alternat1ve B dr1ven by convent1onal methods. The rate of advance was est1mated at 50 feet per day calculated on the bas1s of a s1m1lar proJect 1n s1m1lar rock format1on Assumpt1ons for support were conservat1vely left the same as for the convent1onally dr1ven tunnel, although 1t 1s real1zed that some sav1ngs would probably result 1n actual operat1on. Also, sect1ons of the tunnel may be left unl1ned because the bor1ng mach1ne prov1des a smoother excavated surface than convent1onal methods, thus reduc1ng tunnel fr1ct1on losses. o The assumpt1ons are made that 25% of the tunnel length would requ1re steel r1b support, 25% would be supported by patterned rock bolts and 50% would be unsupported. o Cha1n l1nk mesh for the protect1on of workmen from rock falls 1s prov1ded above the spr1ng l1ne over the full tunnel length. 8-8 J I I' , I I I I J I : l I I I I I -)1 I I I lj I I I (' 1 lj I I I I I I I 1 1 I I I I f~ I I 0 0 0 Est1mated excavat1on costs 1nclude prov1s1on for handl1ng and remov1ng 2000 gallons per m1nute of groundwater 1nflow 1n each tunnel head1ng. Excavat1on and concrete l1n1ng would proceed on a 3-sh1ft bas1s, 6 days per week Construct1on access ad1ts would be located near the upstream and downstream ends of each tunnel alternat1ve In add1t1on two 1ntermed1ate ad1ts would be prov1ded for Alternat1ves C and D. Underground Powerhouse and Assoc1ated Structures For purposes of the current est1mates, the powerhouse has been taken as an underground 1nstallat1on for each alternat1ve, w1th a h1gh pressure penstock shaft and low pressure ta1lrace tunnele The est1mates of cost are based on the follow1ng cond1t1ons 0 All excavat1on and concrete work would proceed on a 3-sh1ft, 6 days per week bas1s. o The powerhouse cavern, valve chamber and ta1lrace tunnel would be excavated by top head1ng and bench. o The penstock and surge shafts would be excavated f1rst by p1lot ra1se, then by downward slash1ng to full d1ameter. o Excavat1on for the hor1zontal penstock and man1fold, access tunnel, cable gallery and draft tubes would be full face. 8-9 8.1.3 o Cha1n l1nk mesh 1s prov1ded for protect1on of workmen over the upper per1meter of all excavat1ons exceed1ng 12 feet 1n he1ghte 0 All permanent excavat1ons would be supported as determ1ned necessary by patterned rock bolts. o Allowance 1s 1ncluded for l1n1ng the upper per1meters of all caverns, chambers and galler1es requ1red for permanent access and those hous1ng vulnerable generat1ng or accessory equ1pment w1th w1re mesh re1nforced shotcrete (th1s may only be needed locally accord1ng to rock cond1t1ons exposed dur1ng construct1on) • o Excavat1on of an exploratory ad1t, and a program of core dr1ll1ng and rock test1ng w1ll precede and conf1rm the su1tab1l1ty of the s1te for the underground powerhouse complex dur1ng the des1gn phase and the costs thereof are 1ncluded 1n the est1mates o The costs 1ncluded for the ma]or 1tems of mechan1cal and electr1cal equ1pment are based on current data w1th added allowance for del1very and transportat1on to the powerhouse s1te. Installat1on costs are also 1ncluded. o Costs of mechan1cal and electr1cal aux1l1ary equ1pment and systems, control and protect1ve equ1pment are 1ncluded. Ta1lrace Channel The est1mates 1nclude a monetary allowance for the construct1on of an outlet channel and r1ver tra1n1ng 8-10 I L~ I i' I 'I I I I I~ I I I I I I 1~ ( i I_ I r' I ( _: {I I I I I (_ I I 8.1.4 8.1.6 works to protect 1t from damage dur1ng floods 1n the r1vero Deta1ls of such requ1rernents are not well def1ned at the present stage but 1t 1s contemplated that extens1ve use would be made of rock spo1l from excavat1on of the powerhouse complex for these purposes. R1ver gravels excavated from the ta1lrace channel would be processed and used to the max1mum extent poss1ble for concrete aggregate. Sw1tchyard In each alternat1ve, due to space l1m1tat1ons, the sw1tchyard would be located outs1de the mouth of the canyon on gently slop1ng land and an appropr1ate allowance 1s 1ncluded 1n the est1mates for the1r cost. Transm1ss1on L1ne and Cable Cross1ng F1eld data acqu1s1t1on has not been performed and 1nformat1on regard1ng construct1on cond1t1ons 1s l1m1ted to aer1al observat1on of the proposed transm1ss1on l1ne al1gnrnent and cable cross1ng. The cost allowed 1n the est1mate for the transm1ss1on l1ne 1s based on exper1ence and 1ncludes the est1mated cost of the submar1ne cable cross1ng to a dead end structure on the Anchorage Shore of Kn1k Arm. S1te Access and Development The est1mates 1nclude costs of construct1ng access and support fac1l1t1es needed for construct1on of the permanent works. These would cons1st bas1cally of the follow1ng 1nstallat1ons. 8-11 o Unload~ng fac~l1ty on t~dewater at Trad~ng Bay, complete w1th rece1v1ng and warehous~ng prov~slons, bulk cement and petroleum fuels storage plus a small camp for operat1ng staff. 0 Gravel surfaced all-weather access roads to construct~on s1tes (F~gure 8-1}. It has been assumed that where ex~st~ng roads are su~tably located, perm~ss~on to use them could be negot~ated w1th the1r owners ~n exchange for ~mprovements that would ~nclude w~den~ng them to full two-way traff~c roads. Br~dges and culverts would be prov1ded at all streams and water courses and where needed for dra~nage. Year- round ma1ntenance costs are ~ncluded throughout the construct1on per~od. o An a~rcraft land1ng facll~ty w~th a runway of suff1c~ent length to handle a~rcraft up to DC-9 I and 737 types, and ground support fac~l~t~es. o For Alternat~ves A, B and E, maJor construct~on camps would be located outs~de but close to the mouth of the McArthur Canyon to accommodate workers employed on the downstream head~ng of the power tunnel, the powerhouse and assoc~ated structures. A second camp for workmen employed on the upstream head1ng of the power tunnel and ~ntake works would be prov~ded JUSt east of the Barr~er Glac~er on the northerly s~de of the r~ver. Th~s camp w~ll also be used for construct~on of the lake outlet works and f1sh fac~l~t~es for Alternat~ve E. 8-12 I 1 I I I _I : \ I 1 II : I I I ) ' I I I[ l ' I I I I II) I I I I I I I I 1/ ';/, ~. '; ' A/OTES: 1.) T OPOCIRAPiiY I ~ F RO;tf U~65 Ot/AO~A io/GLE MAPS Z.)HOI?IZONTAL (;1?10 IS UNIVERSAL TRAAISV~R.SE MEC-"fTOR PROJECTIOA/1 19Z7 A.IOR.TH AMER/CAAJ DATU"'!. 3.)VER71CAL OATUM 115 M~AN LOW/11? LOW WATER. LE6£A.IO -----eXI S T"/AI G ROAD TO 6E I M PRO VED -----cXI S TIA./6 ROAO -----A./EW ACCESS ROAD 0 4 MILES ~~~liiiiiiiiii;;iiiiiil SCALE ' 1° • 2 MILES r -, l _! I I I I I I I I • I I ll I II ( I (~I J I ~ I IJ I I I I I I I I I I '1 I I IJ 0 0 0 0 0 For Alternatives C and D the main construction camp would be located outside the mouth of the Chakachatna Canyon for workers employed on the downstream heading of the power tunnel, the powerhouse and associated structures and also for the second Intermediate access adit to the power tunnel. A second camp for workers employed on the upstream heading of the power tunnel, Intake works and headings driven from the first Intermediate access adit to the power tunnel would be located east of the Barrier Glacier. The construction camps would be self-contained with all needed support facilities which would Include water supply sewage treatment, sol1d waste disposal, catering and medical services. Electrical power during construction IS provided for on the assumption that diesel driven equipment would be used. MaJor compressed air facilities would be required for the excavation work and their cost IS provided for 1n the estimates. Camps needed to accommodate transmission line workers would be l1ght weight "fly camps". Much of the line work would be undertaken In winter and would be avoided during waterfowl nest1ng periods. As construction work approaches completion, all temporary facilities will be dismantled and removed from the site, which will be restored Insofar as Is 8-15 8 2 poss1ble to 1ts or1g1nal cond1t1on, and the cost of such demob1l1zat1on and s1te restorat1on 1s 1ncluded 1n the est1mates. Exclus1ons from Est1mates The est1mates of construct1on costs do not 1nclude prov1s1on for the costs of the follow1ng 1tems. 0 0 0 Owner's adm1n1strat1ve costse F1nanc1ng charges. Escalat1on (Est1mated costs are "overn1ght costs" at January 1982 pr1ce levels. o Land and Land R1ghts. o Water R1ghts. o Perm1ts, l1censes and fees. 0 Sw1tchyard at the Anchorage transm1ss1on l1ne term1nal. 8.3 Construct1on Schedules Typ1cal construct1on schedules are shown on F1gure 8-2 for Alternat1ves A and B, on F1gure 8-3 for Alterna- t1ves C and D, and on F1gure 8-4 for Alternat1ve E. These schedules have as the1r beg1nn1ngs the ex1st1ng schedule for complet1on of the proJect feas1b1l1ty study and preparat1on of the appl1cat1on to the Federal Energy Regulatory Comm1ss1on (FERC) for a l1cense to construct the proJect. 8-16 I I : ~ • L I I ~I I I I I I l \ I I II I I :-J I I : I I I I ~- 1 I I \ I ) ,_j I I l_r ', I L1 [j I I I l_l - 1983--- DESCRIPTION ENGINEERING Feas1b1hty Study FE A C L1cense Exploration Program -P1oneer Road Intake Exploration Program Engrneenng Des1gn PROCUREMENT-TURBINE/GENERATOR CONSTRUCTION Mob1hzat•on and Water/Sewage Plant Tradmg Bay Port and Fac1ht1es A1rstnp Access Roads & Camps -Intake Access Roads & Camps -Downstream Tunro:l -------· --Access Roads & Camps-P werhouse Access Tunnels -Intake Access Tunnels-Downstream Access Tunnels -Powerhouse ~ Power Tunnel -Excavat1on Power T.unnel -Concrete .... Upper Surge Chamber Intake Gate Shaft Intake Tunnel and Lake Tap ' Powerhouse Complex Lower Surge Chamber Penstock and Mamfold Ta1lrace Tunnel Top Headmg & Bench - Tatlrace Canal R 1ver Trammg Works Sw1tchyard I Transm1ss1on Lme Demob1ltzatton and Stte Restoration ~- I 1984 ' CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SCHEDULE AL TEA NATIVES A AND B 1985 1986 1987 1988 p... 1--1- ~rJ ~I IFJ ~t:S ElM ~ ~ ~ ~ ld ~ Ia! - 1\. I I I I "' IJf I I ~ p,... ) t't l;f I I I ; i I t:. IL:. IV - :-1-: I 1-...., I-- 1--"""' 1- I 1- 1989 1990 I I I 1-1-Foe F-1-f- I I IE ps IRI fiV ~I t'il ~( I I I ~ ~ !I 'I ~ I u I! I I I II II I -~J I It: ~:: ::;'1' I, II ~ I ~ I :-Fa r--~ """" I 1-.... i-1-p... ( I I :-I -I ~ I I 1991 -t-~ I:S AI 1 Jf' ~ - 1-1-.. "' 1 .... 1992 AI .LIU Nl ~ ~ i-.... 1- 1993 .::,. ~" L, 1994 Nl fiGURE 8-2 \ l \~ I i I I_ I j I I I i I _) I I I I I I 1 I _) - I I I I I __ 'I I I 1_1 ,- 1 I ), 1 r L_l JJ ----------------------------- 1983 DESCRIPTION ENGINEERING Feas1b1llty Study FERC License Explorat1on Program-P1oneer Road Intake Exploration Program \ Engrneenng Des1gn PROCUREMENT-TURBINE/GENERATOR CONSTRUCTION Mobilization and Water/Sewage Plant Tradmg Bay Port and FacJI!ttes Arrstrrp - Access Roads & Camps -lntal<'e & PH ~cce~ Tunnels-lntalr'! -- Access Tunnels-Mrle 3 5 Access Tunnels-Mtle 7 5 Access Tunnels -Downstream Access Tunnels -Powerhouse Power Tunnel -Excavate Power Tunnel -Concrete Upper Surge Chamber Intake Gate Shaft Intake Tunnel & Lake Tap Powerhouse Complex Lower Surge Chamber Penstock and Mamfold Tarlrace Tunnel Top Headmg & Bench Tarlrace Canal Rrver Trammg Works Swrtchyard Transm1ss1on Lme DemobJhzatJon & S1te Restoratton "- --~-------------- CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SCHEDULE AL TERNATDVES C AND D 1984 1985 1986 1987 ... r, r, I I NGF F ~B El•"l:: 'I I ..... -1- - 1\_ "' u I , i I T I I I : ! 1 j l1 J I' '\. I I I -I : I I I J l '1 E [( v I [""" "' 1" f-F=< I :-- -----L -------- 1988 1989 1990 I 1991 1992 1993 .-1994 --P--1-... :--... ~ I I I ~I 1::) R M I II 'G I fill! .... !"&~ I I I I I' I' II At L UN 11 i) ( NLI ~E ~ ~~ :c. IN A~ ~· s· A HJe e" I 1-II I """" ~ f-1/ -1-~ -1=' jl -i'='" ~ .. !"' Fm 1-p. II Ill ~ r-Ia'< I ~ .. -o:!m !a> "' -""' ""' 1-il II I FIGURE 8-3 I J ~j - \ I I I T I ) I j I ! I I I I ( I I Li I -I I I 1 I L ) I I J ' 1' I I li_ \ I LJ : [ L_) DESCRIPTION ENGINEERING Feas1b1l1ty Study FER C L1cense ExploratiOn Program -P1oneer Road Intake Exploration Program Engmeenng Des1gn PROCUREMENT-TURBINE/GENERATOR CONSTRUCTION MobJ11zat1on and Water/Sewage Plant Tradmg Bay Port and Fac1llttes - A1rstnp Access R cads & Camps -Intake Access Roads & Camps-Downstream Tunnel !l,~cP.~ t\oads & Cafrps-Pc.. n I -l' Access Tunnels-Intake Access Tunnels -Downstrearn Access Tunnels-Powerhouse Ftsh Facll1t1es Chakachatna 01ke and Sp1llway ... Power Tunnel-ExcavatiOn Power Tunnel -Concrete Upper Surge Chamber Intake Gate Shaft Intake Tunnel and Lake Tap Powerhouse Complex Lower Surge Chamber Penstock and Mantfold Tailrace Tunnel Top Headmg & Bench Ta1lrace Canal R1ver Trammg Works Sw1tchyard Transm1ss1on Lme Demob1hzatton and S1te Restoration 1983 \ I CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SCHEDULE AlTERNATIVE E 1984 1985 1986 1987 \ M3F F ~8 IT 1-""" ~ I" I ' I I I : I ~ 1-J I I I ! I; I ~ 1- """' ~ t- i- ·--------- 1988 1989 1990 1991 1992 1993 ~ 1994 I I I I I I I I I I '"" J..= 1-1-~ "-1-I~ 1-1- """" I EM E i>S RE M. p.ft trG -P- I ' I l I I : ' I I I I ! J. Ll u Nl l ~ fU f'l .Ill l~ I " ~· ~ I II ~ :J CJ v Cbl\ CF E E ~s l:iY s trt R ru tl I I """ ~ I I 1-1-.. ~ '""" ~ """ lo-p... 1--1-= .... """" 1-1-1-I rl If ;..... 1-II I I """ I p... """" .. ... ., p I-' fiGURE 84 l I I I I I , r L I I The assumpt1on has been made that the l1cense appl1cat1on would be subm1tted to FERC March 1, 1984" Assum1ng also that the FERC l1cens1ng process cont1nues 1n much the same manner as 1t does at the present t1me, an early step w1ll be the preparat1on of an env1ronmental assessment of the proJect by FERC staff. Th1s generally takes about 12 months follow1ng wh1ch 1s a 60-day per1od for rev1ew and comment by 1nterested agenc1es. Thus, by the end of Apr1l, 1985, 1t should have become clear whether there are any outstand1ng unresolved 1ssues If there are not, then 1t would be poss1ble to forecast w1th reasonable certa1nty that the FERC l1cense would be 1ssued 1n early 1986, 1n wh1ch event there would not appear to be any reason why the construct1on of access fac1l1t1es and camp 1nstallat1ons could not commence by June 1, 1985. In order to prov1de adequate lead t1me to commence des1gn and prepare plans and spec1f1cat1ons for the construct1on of access fac1l1t1es, des1gn eng1neer1ng of the proJect would need to commence at the beg1nn1ng of 1985 Not1ng that there 1s a poss1b1l1ty that FERC m1ght also requ1re complet1on of an exploratory ad1t and rock test1ng program at the powerhouse s1te oefore 1ssu1ng the proJect l1cense, June 1, 1984 would appear to be a log1cal t1me to commence that program. Mak1ng an early start 1n the manner descr1bed above would perm1t the plant to commence commerc1al operat1on a year earl1er than 1f the des1gn of the proJect and construct1on of 1nfrastructure d1d not commence unt1l after the FERC l1cense had been 1ssued. 8-23 Construct1on of the power tunnel l1es on the cr1t1cal path for complet1on of development v1a the McArthur R1ver 1n Alternat1ves A, B, and E. For convent1onal excavat1on methods assumed for Alternat1ves A and B the schedule was based on tunnel excavat1on advancement at an average rate of 26 feet per day 1n each head1ng. At that rate, excavat1on would be completed 1n approx1mately 3-1/2 years. For excavat1on by bor1ng mach1ne assumed for Alternat1ve E the schedule was based on net advancement of 50 feet per day from one head1ng at wh1ch rate the excavat1on would be completed 1n approx1mately the-same t1me. Placement of the concrete l1n1ng would proceed generally concurrently w1th the excavat1on. Total construct1on t1me for the tunnel 1s thus 50 months and the f1rst un1t 1n the powerhouse could be started up by August 1, 1991. As d1scussed above a sav1ng 1n t1me m1ght be effected 1f any sect1ons of the tunnel can be left unl1ned as a result of smoother bor1ng mach1ne excavat1on and reduct1on of rock shatter1ng. For development v1a the Chakachatna R1ver 1n Alternat1ves C and D, the ab1l1ty to prov1de two 1ntermed1ate construct1on access ad1ts enables the tunnel construct1on to be completed w1th1n 32 months, or 18 months less than for the McArthur tunnel T1mely del1very of the turb1nes and generators, and construct1on of the powerhouse complex becomes more cr1t1cal. Assum1ng an early start on s1te access and 8-24 r I I I I I I I I I I ~ I I I I ~I I I I I 1 r I L I~ I I L_! development as descr~bed above for Alternat~ves A and B, the f~rst un~t ~n Alternat~ves C and D could be started up by February 1, 1990, or 18 months earl~er than would be the case w~th Alternat~ves A, B and E. 8-25 ECONOMIC EVALUATION l - - I I l I L_ I ~ I I I 'I L l 9 0 9.1 ECONOMIC EVALUATION General Dur1ng the 1n1t1al proJect stud1es carr1ed out 1n 1981, an evaluat1on was made of the econom1c tunnel d1ameter and econom1c tunnel length for the four bas1c alternat1ve schemes developed at that t1me, Alternat1ves A, B, C & D (descr1bed 1n Sect1on 3) Th1s econom1c study was made us1ng tunnel costs calculated for tunnel excavat1on by convent1onal dr1ll and shoot methods. Subsequent stud1es performed 1n 1982 1nd1cated that cost sav1ngs w1ll be ach1eved 1f the tunnel would be dr1ven by tunnel-borlng mach1ne. Alternat1ve E 1s based on tunnel bor1ng mach1ne excavat1on. These stud1es are d1scussed 1n Sect1on 8 No re-exam1nat1on of the econom1c tunnel d1ameter or length has been made us1ng these mod1f1ed tunnel costs, but any change 1n econom1c d1ameter or length of tunnel 1s cons1dered to be small. Determ1nat1on of the econom1c tunnel d1ameter 1nvolves compar1ng the construct1on costs of tunnels of vary1ng d1ameters, w1th the present worth of the d1fference 1n power produced over the l1fe of the proJect as a result of the changes 1n hydraul1c loss 1n the tunnel as the d1ameter 1s var1ed The econom1c tunnel length 1s determ1ned from an econom1c balance between the cost of 1ncreas1ng the tunnel length to develop add1t1onal head on the powerhouse, and the present worth of the add1t1onal power produced by the h1gher head over the l1fe of the proJect. It should be noted that these econom1c evaluat1on stud1es were based on econom1c parameters preva1l1ng 1n 1981. These parameters wh1ch 1nclude cap1tal costs of thermal generat1ng plants and fuel costs for both coal and natural gas have, of course, now been superseded. In 9-l 9 2 9.3 9.3.1 future stud1es, the 1nfluence of updated econom1c parameters on the econom1c tunnel d1ameter and length should be made Parameters for Econom1c Evaluat1on Alaska Power Author1ty has developed the follow1ng parameters for econom1c analyses of hydroelectr1c proJects. Inflat1on Rate Real D1scount Rate Econom1c L1fe of Hydroelectr1c ProJects Econom1c l1fe of thermal plants (convent1onal coal f1red or comb1ned cycle) 0% 3% 50 years 30 years In s1z1ng the var1ous proJect elements, 1.e., tunnel d1ameter and length, the value of power generated by the hydroelectr1c proJect has been cons1dered equal to the cost of the equ1valent power generated thermally by coal f1red plant or by natural gas f1red comb1ned cycle plant. As agreed w1th APA, 1n order to arr1ve at a proJect cost wh1ch can be read1ly compared w1th that for the Sus1tna ProJect a 50% plant factor has been used for determ1n1ng the 1nstalled capac1ty of the power plants d1scussed 1n th1s report. Future stud1es should concentrate on ref1n1ng the preferred plant factor for the proJect. Cost of Power from Alternat1ve Sources General To ensure un1form1ty of data between the var1ous feas1b1l1ty stud1es of hydroelectr1c proJects wh1ch are currently 1n progress, 1nclud1ng the Sus1tna Hydroelectrlc ProJect, APA requested that the follow1ng 9-2 I I I 'J I I l I I I I I I I I I ~I I I ~~ \ I L I 1 I : I I I l _I L ; l il I I I I I I I 9.3.2 sources be used for the development of cost of power from alternat1ve thermal generat1on (1) Acres Amer1can Incorporated report 11 Sus1tna Hydroelectr1c Pro]eCt 11 Task 6 Development Select1on Report, Append1ces A through I, July 1981 for construct1on cost of coal f1red and comb1ned cycle thermal plants. (2) Battelle Pac1f1c Northwest Laborator1es, for the cost of operat1on and ma1ntenance and fuel for coal f1red and comb1ned cycle thermal plants. Data on these 1tems were obta1ned dur1ng a v1s1t to Battelle's off1ce on September 1, 1981. Construct1on Cost (a) Coal f1red thermal plant The Acres Amer1can report referred to above develops the construct1on cost of a 250-MW coal f1red thermal plant at Beluga 1n 1980 dollars to be $439,200,000 d1rect construct1on cost and $627,650,000 total cost 1nclud1ng 16% cont1ngency, 10% for construct1on ' fac1l1t1es and ut1l1t1es and 12% for Eng1neer1ng and Adm1n1strat1on, but not 1nclud1ng 1nterest dur1ng construct1on. Th1s total cost corresponds to $2510/kW. Includ1ng 1nterest dur1ng construct1on at 3 percent per year for a 6 year construct1on per1od, the total cost amounts to $2706/kW. (Th1s d1ffers but l1ttle from the $2744/kW value g1ven 1n Table B.l3 of the Acres Report apparently because of some round1ng of numbers 1n the Acres calculat1on and apparently sl1ght d1fference 1n cash flow dur1ng the construct1on per1od.) 9-3 9.3.3 9 3 4 (b) Comb1ned Cycle Plant The Acres Amer1can report also develops the construct1on cost of a 250-MW comb1ned cycle plant 1n 1980 dollars to be $121,830,000 d1rect construct1on cost and $174,130,000 total cost 1nclud1ng 16% cont1ngency 10% for construct1on fac1l1t1es and ut1l1t1es and 12% for Eng1neer1ng aDd Adm1n1strat1on, but not 1nclud1ng 1nterest dur1ng construct1on. Th1s corresponds to $697/kW When 1nterest dur1ng construct1on 1s added at 3 percent per year, the total cost 1s $707 5/kW. Operat1on & Ma1ntenance Cost Data obta1ned from Battelle 1s summar1zed below for 1980 pr1ce levels. (a) Coal-f1red Thermal Plant F1xed Operat1on and Ma1ntenance $16 71/kW/year Var1able Operat1on and Ma1ntenance 0.6 mllls/kWh. Escalat1on above general 1nflat1on rate 1.9% unt1l year 2012 w1th no escalat1on after 2012. (b) Comb1ned Cycle Plant F1xed Operat1on and Ma1ntenance $35 00/kW/year Var1able Operat1on and Ma1ntenance 0 m1lls/kWh. Escalat1on above general 1nflat1on rate 1.9% unt1l year 2012 w1th no escalat1on after 2012. Fuel Cost Data obta1ned from Battelle 1s surnrnar1zed below for 1980 pr1ce levels 9-4 I - I I I I I I I I \ I I I { ~ I l I L I I I I I I L I I I I : (a) Coal from Beluga Fuel cost $1.09/rnlll. BTU Escalat1on above general 1nflat1on rate 1.5% unt1l year 2012 w1th no escalat1on after 2012 Heat Rate 10,000 BTU/kWh. (b) Natural Gas -Cornb1ned Cycle Plant The natural gas pr1ces as est1rnated by Battelle for the future years are g1ven 1n Table 9-1 Heat rate 7500 BTU/kWh TABLE 9-1 NEW CONTRACT GAS PRICE (AML&P)-ANCHORAGE Year Gas Pr1ce $/M1ll BTU 1980 1 08 1981 1.08 1982 1 09 1983 1.09 1984 1.09 1985 1.09 1986 1.35 1987 1.56 1988 1.65 1989 1.89 1990 2.11 1991 3 62 9-5 9 4 1992 1993 1994 1995 3.74 3 86 3 98 4 ll Forecast escalat1on after 1995 = 3% per year unt1l the year 2012, and no escalat1on thereafter. Value of Hydro Generat1on The value of the hydro generat1on 1s establ1shed by determ1n1ng the cost of generat1ng power from alternat1ve sources. For the purpose of th1s study an analys1s has been made of the cost of alternat1ve coal-f1red and comb1ned cycle generat1on, us1ng the bas1c cost data presented prev1ously 1n Sect1on 9.3. The annual cost of 1nterest, deprec1at1on and 1nsurance for the alternat1ve thermal plants were calculated on the follow1ng bas1s Interest Deprec1at1on (30 year l1fe) Insurance Annual Charge on Cap1tal Cost 3 0% 2 1% 0.25% 5 35% Based on an arb1trary select1on of 1990 as the 1n-serv1ce date for the Chakachamna ProJect and exam1n1ng a f1fty year per1od, equal to the econom1c l1fe of the hydro plant, and us1ng the un1t costs for thermal generat1on d1scussed above, comparat1ve costs were prepared for each year of the 50 year per1od of the cost of generat1ng power at 50% load factor by each of the two alternat1ves, convent1onal thermal us1ng Beluga coal and comb1ned cycle 9-6 ' I I I I I I I I ' I \_I I ! I I ) I I I I ~~ I ~I I I I I I I I l_l I I I I I I I I I I I us1ng gas. These annual costs over the SO year per1od were then used to determ1ne the1r present worths at the f1rst year of generat1on taken as 1990 The calculat1ons were performed on a cost per kWh bas1s and are presented 1n Tables 9-2 & 9-3 for the convent1onal coal f1red and comb1ned cycle cases respect1vely. The level1zed annual cost of generat1on by a coal f1red plant us1ng Beluga coal 1s calculated to be 5S.60 m1lls per kWh compared w1th 75.21 m1lls per kWh for the comb1ned cycle plant, based on 50% load factor generat1on The h1gher cost for the comb1ned cycle plant 1s due pr1mar1ly to a h1gher 1n1t1al fuel cost, a much h1gher escalat1on on the cost of fuel, and somewhat h1gher operat1on and ma1ntenance cost. Taken collect1vely these more than offset the much lower annual charge on the cap1tal cost of construct1ng the cornb1ned cycle plant. The cost of power produced by the coal f1red plant was therefore adopted as the alternat1ve for establ1sh1ng the value of hydro generat1on. The cap1tal cost of a hydro plant wh1ch g1ves a level1zed annual cost over the SO year l1fe equal to the level1zed annual cost of the coal f1red thermal plant of 55.60 m1lls per kWh, based on 50% plant factor, and 1nclud1ng a cred1t of 5% less 1nstalled capac1ty requ1red 1n a hydro plant because of the reduced system reserve requ1rements w1th hydro generat1on, 1s calculated to be $6,117 per kW. Th1s total cost 1ncludes cont1ngency, construct1on camp fac1l1t1es, eng1neer1ng, and construct1on management and 1nterest dur1ng construct1on. 9-7 Year 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 NOTE TABLE 9-2 ( Sheet 1 of 2 ) COAL FIRED PLANT COST OF GENERATING POWER AT 50% LOAD FACTOR AmortJ.zatJ.on Present & Insurance O&M Fuel Total Worth 33.02 5.32 12.65 50.99 49.50 33 02 5 42 12.84 51.28 48 34 33.02 5.52 13.03 51 57 47.19 33 02 5.63 13 23 51.88 46.09 33.02 5.74 13 43 52.19 45 02 33.02 5.84 13 63 52.49 43.96 33.02 5.96 13 83 52.81 42.94 33 02 6.07 14 04 53 13 41.94 33.02 6.18 14 25 53.45 40.96 33.02 6 30 14 46 53 78 40 02 33.02 6.42 14 68 54.12 39.10 3J.02 6.54 14.90 54.46 38.20 33.02 6.67 15.12 54.81 37 32 33.02 6.79 15 35 55.16 36 47 33.02 6 92 15 58 55.52 35 64 33.02 7.06 15 82 55.90 34 84 33.02 7.19 16 05 56.26 34.04 33.02 7.33 16.29 56 64 33 27 33 02 7 47 16 54 57.03 32.52 33.02 7.61 16.79 57.4 2 31 79 33.02 7.75 17 04 57 81 31 08 33 02 7.90 17.29 58 21 30 38 33.02 7 90 17 29 58.21 29 49 33.02 7.90 17.29 58.21 28 64 33.02 7.90 17 29 58.21 27 80 946 54 EscalatJ.on rates above the general escalatJ.on rate are as follows. AmortJ.zatJ.on & Insurance -NJ.l. OperatJ.on & MaJ.ntenance -1.9% for fJ.rst 22 years only Fuel -1.5% for fJ.rst 22 years only. 9-8 I I I I I I I I _I --1 I \ I I I I I TABLE 9-2 (Sheet 2 of 2) COAL FIRED PLANT COST OF GENERATING POWER AT 50% LOAD FACTOR Amort1zat1on Present Year & Insurance O&M Fuel Total Worth Fwd. 946.54 26 33 02 7.90 17.29 58.21 26.99 27 33.02 7.90 17.29 58.21 26.21 28 33.02 7.90 17.29 58 21 25.44 29 33 02 7.90 17.29 58.21 24.70 30 33 02 7.90 17.29 58.21 23.98 31 33.02 7.90 17.29 58 21 23 28 32 33.02 7.90 17.29 58.21 22.61 33 33.02 7.90 17.29 58.21 21 95 34 33 02 7. 90 17.29 58.21 21.31 35 33.02 7.90 17.29 58 21 20.69 36 33 02 7.90 17.29 58.21 20 08 37 33 02 7.90 17.29 58 21 19.50 38 33.02 7.90 17.29 58.21 18.93 39 33.02 7. 9 0 17.29 58.21 18.38 40 33.02 7.90 17 29 58.21 17.84 41 33.02 7.90 17.29 58.21 17 32 42 33 02 7 90 17.29 58.21 16.82 43 33 02 7. 9 0 17.29 58.21 16 33 44 33 02 7.90 17 29 58r 21 15.85 45 33 02 7.90 17 29 58.21 15 39 I I I 46 33.02 7.90 17.29 58.21 14 94 47 33.02 7.90 17.29 58 21 14.51 48 33.02 7.90 17.29 58.21 14.09 I 49 33.02 7.90 17 29 58.21 13 68 50 33.02 7.90 17.29 58 21 13.28 i I 1430 64 I I - 1- ( I Equ1valent Level1zed Annual Cost = 55~60 m1lls/kWh. I 1 I I I 9-9 Year 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 NOTE TABLE 9-3 (Sheet 1 of 2) COMBINED CYCLE PLANT COST OF GENERATING POWER AT 50% LOAD FACTOR AmortJ.zatJ.on Present & Insurance O&M Fuel Total Worth 8 64 9 64 21.1 39.38 38 23 8.64 9.82 36 2 54 66 51.52 8.64 10 01 37.4 56.05 51 29 8.64 10.20 38.6 57.44 51.03 8.64 10.39 39.8 58.83 50 75 8.64 10.59 41.1 60 33 50 53 8.64 10.79 42.33 61.76 50.22 8.64 11.00 43 60 63.24 49 92 8.64 11 21 44.91 64.76 49 63 8.64 11.42 46.26 66.32 49.35 8 64 11.64 47.65 67.93 49 07 8.64 11 86 49.08 69 58 48 80 8.64 12.08 50.55 71.27 48 53 8.64 12.31 52.06 73 01 48 27 8 64 12.55 53.63 74.82 48 02 8.64 12.78 55 23 76.65 47 77 8.64 13.03 56 89 78.56 4 7 53 8 64 13.28 58.60 80 52 47 30 8.64 13 53 60.36 82.53 47 07 8 64 13.78 62.17 84 59 46.84 8.64 14.05 64.03 86.72 46 62 8.64 14.31 65 95 88.90 46 40 8.64 14.31 65.95 88 90 45 04 8 64 14.31 65.95 88.90 43 73 8.64 14 31 65 95 88.90 42 46 1195 92 EscacalatJ.on rates above the general escalatJ.on rate are as follows. AmortJ.zatJ.on & Insurance -NJ.l. OperatJ.on & MaJ.ntenance -1.9% for fJ.rst 22 years only. Fuel -1.5% for fJ.rst 22 years only. 9-10 I I I I i I I I I I _I I I I j_; (~ I I I I \ ~ I I I I - I i - I I I 'I I I I '-I Year 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 so TABLE 9-3 (Sheet 2 of 2) COMBINED CYCLE PLANT COST OF GENERATING POWER AT 50% LOAD FACTOR Arno rt1 za t1on & Insurance 8.64 8.64 8.64 8.64 8.64 8.64 8.64 8.64 8 64 8.64 8.64 8.64 8 64 8.64 8.64 8.64 8. 6 4 8 64 8.64 8.64 8. 6 4 8.64 8.64 8.64 8.64 O&M 14.31 14.31 14.31 14.31 14 31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 14.31 Fuel 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 65.95 Total 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88 90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 88.90 Equ1valent Leve11zed Annual Cost = 75.21 mllls/kWh. 9-11 Present Worth 1195.92 41 22 40.02 38.86 37.72 36.63 35.56 34 52 33 52 32.54 31.59 30.67 29.78 28.91 28 07 27 25 26.46 25 69 24.94 24 21 23 51 22 82 22.16 21.51 20 89 20.28 1935 25 9.5 Econom1c Tunnel S1z1ng The econom1c d1ameter of the ma1n power tunnel has been 1nvest1gated by compar1ng the 1ncremental cost of vary1ng the tunnel d1ameter w1th the 1ncremental value of the d1fference 1n power produced as a result of such var1at1on 1n tunnel d1ameter For the same powerhouse flow, 1ncreas1ng the tunnel d1ameter reduces the head losses 1n the tunnel thereby 1ncreas1ng the total head on the powerhouse w1th a consequent 1ncrease 1n power product1on. In establ1sh1ng the var1at1on 1n est1mated tunnel construct1on cost 1t has been assumed that the tunnel w1ll be fully concrete l1ned w1th the typ1cal horseshoe sect1on shown 1n F1gure 3-2 and would be excavated by convent1onal dr1ll and shoot methods Future stud1es should evaluate the mer1ts of a norn1nally unl1ned tunnel. It should also be noted that when the method of dr1v1ng the tunnel by tunnel bor1ng mach1ne was exam1ned 1n 1982, no attempt was made to ref1ne the econom1c tunnel d1ameter For the case of Alternat1ves A & C w1th no water release to meet 1nstrearn flow requ1rements 1n the Chakachatna R1ver (1.e., all controlled water be1ng d1verted for power product1on purposes) , F1gure 9-1 shows the plot of est1mated tunnel construct1on cost and value of power product1on w1th var1at1on 1n tunnel d1ameter Th1s curve shows that the econorn1c d1ameter of a concrete l1ned tunnel 1s 25 feet. In Alternat1ve B, w1th the flow d1verted to a powerhouse s1ted on the McArthur R1ver, but w1th water reserved for 1nstream flow requ1rernents 1n the Chakachatna R1ver a separate study to establ1sh the econom1c d1ameter was not made Instead, as an approx1rnat1on, the tunnel d1arneter was selected such that 9-12 I I I I I - I I I I I I 70 60 \ ~ rTOTAL COST 50 \0 f l I_J I I I I_ I ,__, I I L \ I I I I lJ 0 \ ->4 <1)-40 I ) ~ ~ til 0 t.J ~ ~~ ~ r.::l ~ 30 r----__ -'" ~ \. ..... ~ ~ \ \_ANNUAL CO~T -$29.29 x 10 6 ~ ~ ~ -~ ~ 20 ~ ~ ~ OPTIMUM TUNNEL DIA 25' __.E COST ~ 10 ........... ~ hL ~POWER LOSS COST r----_ ~ " p-- 0 -17 18 20 22 24 26 28 30 TUNNEL DIAMETER -FEET I I l J ECONOMIC TUNNEL DIAMETER FIGURE 9-1 I I I r 1 \_ I I I I I I I I 1 1 I I I l~l ~ l I I I I I I I I I I I : I 9 6 the veloc1ty of flow through the tunnel w1th the generat1ng un1ts operat1ng at full output and at full level at Lake Chakachamna would be the same as that obta1ned under these same operat1ng cond1t1ons 1n Alternat1ve A for wh1ch the econom1c d1ameter had been calculated. Th1s approx1mat1on g1ves a 23-foot horseshoe tunnel. In the case of Alternat1ve D where only an average release of 30 cfs flow 1s ma1nta1ned below Chakachamna, Lake, the 25 foot d1ameter tunnel was reta1ned, s1nce the powerhouse flow d1ffers by less than 1%. In the case of Alternat1ve E developed 1n 1982, based on dr1v1ng the tunnel by tunnel bor1ng mach1ne, a 24 foot d1ameter c1rcular tunnel was selected ThlS lS hydraullcally equ1valent to the 23 foot d1ameter horseshoe shaped tunnel 1n Alternat1ve B If future geolog1c stud1es conf1rm the su1tab1l1ty of the rock for mach1ne bor1ng, the econom1c tunnel d1ameter should be re-evaluated. Econom1c Tunnel Length For both bas1c alternat1ve developments by d1vers1on to the McArthur R1ver or downstream along the Chakachatna R1ver, an exam1nat1on has been made of the econom1c tunnel length. As the powerhouse 1s moved downstream to develop add1t1onal head, the power tunnel becomes longer and hence more costly. The econom1c tunnel length 1s therefore determ1ned from an econom1c balance of est1mated tunnel construct1on cost and value of power produced. Based on the value of the hydro generat1on as d1scussed 1n Sect1on 9 4, the present worth of the power produced by 1 foot of head when all controlled water 1s 9-15 used for power generation Is equal to approximately $3,500,000 which corresponds to $139,000 annually over the 50 year life of the plant at 3% rate of Interest. The economic balance Includes consideration of the additional estimated tunnel construction cost by Increasing the tunnel length, additional powerhouse cost to develop the power produced from the additional head and the value of the additional power generated by the additional head developed. The additional head Is based on the Increased gross head due to the lower tailwater obtained by extending the tunnel less the Increased friction head loss In the longer tunnel. Figure 9-2 and 9-3 show respectively the plots of the economic tunnel length for the development via the McArthur River and down the Chakachatna River The final selected tunnel lengths and corresponding powerhouse locations are shown In Figures 3-2 and 3-3. 9-16 1 I I I I I I I I I I I I I ~I I I I I I I r--- 1 1,-------) 120 100 \0 0 .-4 :>< U>- I ~ 80 ~ § A ~ E-1 60 tr.l 0 u ~ tr.l ::> 0 gj [31 40 0 P-1 -...:I ~ ~ 20 0 35 ' '~-J -__ I r -.... ~ ~RE~NUE ~ GENERATED FROM POWER I f I $88xl06 ~MAXIMUM ANNUAL POWER ~VENUE == 'I v-----\ - I --...e T v \. r-NET ANNUAL REVENUE I GENERATED FROM POWER I q> / ~OPTIMUM TUNNEL LENGTHo53 9 400' r -...... \... TUNNEL/POWERHOUSE COST If" -1"\. --..., - 40 45 50 55 60 65 TUNNEL LENGTH-FT x 1000 70 - 75 McARTHUR TUNNEL ECONOMIC LENGTH FIGURE 9-2 I 120 " 100 \0 0 """' ~ (I)- ~ 80 ~ ~ ~ ~ Cll 60 8 ~ Cll ::;J 0 ~ ~ 40 ,:~., ....... v ~ ANNUAL REVENUE GENERATED FROM POWER -\ ~ ~ ~ OPTIMIZATION NOT POSSIBLE-TUNNEL- LENGTH LIMITED BY TOPOGRAGHY AT ~\ ~ Ci1 ~ON MOUTH ~ - NET ANNUAL REVENUE v GENERATED~ _.o..- ~ - ~IJ' ..... ..... -~ ,. .... ""' ~ -~ 20 --.. -..... ~ \ L TUNNEL/POWERHOUSE COST 0 45 so 55 60 65 70 75 80 85 TUNNEL LENGTH-FT X 1000 CHAKACHATNA TUNNEL ECONOMIC LENGTH FIGURE 9-3 4 ~~~=---= -~~~~-=--~---1 ~~ ~ ~ -. -c __ ~-.--, COORDINATION I I ¥ ~ I I ( r \ t t I I ~ 1 I f \ J I \ I i; 1....., ~~I I I_ I 10 0 10 1 10 2 10 2.1 COORDINATION Introduct1on Dur1ng the course of the proJect stud1es, coord1na- t1on w1th var1ous 1nterested part1es was conducted v1a 1nformal contacts, wr1tten commun1cat1on, and formal meet1ngs 1n order to afford these part1es an opportun1ty to make the1r 1nterests 1n the proJect known and to enable the Power Author1ty to respond to quest1ons and concerns about var1ous aspects of the proJect In th1s sect1on of the report, cop1es of correspondence and meet1ng notes are reproduced to demonstrate coord1nat1on between the Power Author1ty and 1nterested agenc1es HUMAN RESOURCES Meet1ng -December 10, 1981 Representat1ves of U S Bureau of Land Manangement, Nat1onal Park Serv1ce, and the Alaska State Archae- olog1st were 1nv1ted to attend a meet1ng w1th repre- sentat1ves of Bechtel, Woodward-Clyde Consultants on December 10, 1981 A copy of the meet1ng notes pre- pared by Bechtel, Woodward-Clyde Consultants follows 10-1 CHAKACHAMNA HYDROELECTRIC PROJECT JOB No 14879 MEETING NOTES DATI: December 10, 1981 LOCATION Bus1ness Park, Anchorage, Alaska PARTICIPANTS Name Bob Loder Dav1d Cornman H1ke Joyce Chuck Holmes Dave Hobraten Ba1ley Breedlove John Isaacs Organ1zat1on Bechtel Bechtel 1-loodward-Clyde Consultants Subcontractor to Woodward-Clyde Consultants Anchorage D1str1ct Off1ce of the Bureau of Land Management Nat1onal Park Serv1ce Woodward-Clyde Consultants SUBJECT Human Resources Scop1ng Meet1ng Representat1ves from Bechtel C1v1l and M1nerals and Woodward-Clyde Consultants (WCC) presented a summary of the proposed 1982 Human Resources stud1es and the results of the 1981 reconna1ssance program to representat1ves of the Anchorage D1str1ct Off1ce of the Bureau of Land Management (BLM) and the Nat1onal Park Serv1ce (NPS) The State Archaeolog1st was unable to attend the meet1ng An 1ntroduct1on descr1b1ng the proJect, team organ1zat1on, and potent1al development schemes was prov1ded by Bob Loder Th1s 1ncluded conceptual des1gn and locat1ons of the proJect alternat1ves M1ke Joyce presented a general overv1ew of the env1ronmental program, followed by Jon Isaacs, who d1scussed the 1981 Human Resources reconna1ssance and the 1982 work program The agency representat1ves each had rece1ved a copy of the 1982 proposed work plan pr1or to the meet1ng At the conclus1on of the presentat1ons, the agency representat1ves were asked to supply oral and subsequently wr1tten comments express1ng the1r concerns w1th the proposed hydropower proJeCt and the proposed human resources work plan for 1982 The maJor concerns expressed orally at tn1s meet1ng are listed below BLM o m1neral1zat1on of the area, and potent1al resource extract1on should be 1nvest1gated o 1mpacts on f1sh and w1ldl1fe resources are l1kely to be the b1g 1ssue, econom1c 1mpacts on the Cook Inlet f1shery should be determ1ned 10-2 I , r ~ l - v \ I I I - I I I I l-I I ~ I 0 ~ I I I I / I I I I j \ I ~s 0 w~th regard to perm~ts, ~t ~s l~kely that no perm~ts for 1982 stud~es w~th~n the power s~te w~thdrawal ~11 be requ~red Out- s~de of the w~thdrawal, perm~ts w~ll be requ~red for act~v~t~es ~nvolv~ng s~gn~f~cant surface d~sturbance, such as dr~ll~ng or road construct~on o ~nput from Cook Inlet Reg~on Inc (CIRI), Tyonek Nat~ve Corpora- t~on (TNC) and the State of Alaska should be sol~c~ted o maps convey~ng land to the Nat~ve corporat~ons and state should be checked for road and powerl~ne easements o concern~ng proJect construct~on and operat~on, waste d~sposal from tunnel construct~on w~ll be an ~ssue of concern BLM would have no problems w~th road construct~on w~th~n the power s~te boundar~es o use of the proJect related roads and where they m~ght put use pressure are of concern, part~cularly ~n the v~c~n~ty of Chaka- chamna Lake, where Lake Clark Nat~onal Park could be affected o the potent~al drawdown of Lake Ken~buna by the proJect needs to be ~nvest~gated o ~nterest was expressed on Mt Spurr's ~nfluence on the proJect o potent~al effects to salmon runs enter~ng Lake Clark Nat~onal Park (Ken~buna Lake) w~ll be ~nvest~gated o potent~al ~mpacts to the proJect from glac~ers and volcan~c act~v~ty were noted o s~tuat~on problems s~m~lar to those ant~c~pated on Sus~tna, may occur on the Chakachamna ProJect In add~t~on to these comments, several quest~ons where asked about the b~olog~cal (w~nter f~sh d~str~but~ons, peregr~ne falcon) and eng~neer~ng (tunnel construct~on) aspects of the proJect 10-3 '" 10 2 2 10 3 10.3 1 Response The concerns expressed by these agenc1es were noted and used for gu1dance 1n the plann1ng and conduct of prOJect stud1es F1sh and w1ldl1fe aspects were taken up w1th the1r respect1ve Federal and State Agenc1es In1t1al contacts were made w1th Cook Inlet Reg1on, Inc. (CIRI) and Tyonek Nat1ve Corporat1on (TNC) An attempt to schedule a meet1ng w1th TNC was unsuccessful but future meet1ngs are planned Contacts and a meet1ng also took place w1th the Nat1onal Park Serv1ce and the Super1ntendent of Lake Clark Nat1onal Park. B1olog1cal Stud1es Meet1ng -December 11, 1981 A meet1ng was convened 1on December 11, 1981 between representat1ves of Alaska Department of F1sh and Game, Nat1onal Mar1ne F1sher1es Serv1ce, U s. F1sh and W1ld- l1fe Serv1ce and representat1ves of Alaska Power au- thorlty, Bechtel and Woodward-Clyde Consultants The purpose of the meet1ng was to sol1c1t and d1scuss verbal comments on proposed 1982 b1olog1cal stud1es for the Chakachamna Hydroelectr1c ProJect A copy of the meet1ng notes prepared by Bechtel, Woodward-Clyde 1s reproduced on the follow1ng pages 10-4 I) I~ t \ \ I I I I ( I H' I _I ' I I ,) l I ...... /II-I - ~HAKACHMNA HYDROELECTRIC PROJEC1 JOB 14879 MEETING NOTES DATE December 11, 1981 LOCATION Bus1ness Park, Anchorage, Alaska PARTICIPANTS Alaska Department of F1sh & Game Carl Yanagawa Don McKay Ken Tarbox Kelly Hepler Larry Heckart Paul Ruesch Ron Stanek Tom Arm1nsk1 Bechtel Dav1d Cornman Bob Loder SUBJECT Chakachamna Agency Scop1ng Meet1ng Nat1onal Mar1ne F1sher1es Serv1ce Brad Sm1th Dave Ferrel Alaska Power Author1ty Er1c Marcheg1an1 Woodward-Clyde Consultants M1ke Joyce Larry Rundqu1st Paul Hampton Braxton Dew Wayne L1fton Jon Isaacs Representat1ves from Alaska Power Author1ty (APA), Bechtel C1v1l and M1nerals, and Woodward-Clyde Consultants (WCC) presented a summary of the proposed 1982 b1olog1cal stud1es and the results of the 1981 reconna1ssance efforts to repre- sentat1ves from the Alaska Department of F1sh and Game (ADF&G), Nat1onal Mar1ne F1sher1es Serv1ce (NMFS), and US F1sh and W1ldl1fe Serv1ce (FWS) The purpose of the meet1ng was to d1scuss and sol1c1t verbal comments on proposed b1olog1cal stud1es for the 1982 Chakachamna Hydroelectr1c ProJect 10-5 An ~ntroduct~on descr~b~ng the proJect, ~ts proJect team organ~zat~on, and potent~al development scheme was prov~ded by Er~c Marcheg~an~, Bob Loder described the conceptual design and locations of the five proJect alternatives and Mike Joyce Introduced the environmental presentation The Woodward-Clyde task leaders (hydrology, aquatic, and Wildlife bi- ology) then briefly described the results of the two reconnaissance efforts In 1981 and the proposed studies for 1982 The agency representatives each had received a copy of the 1982 proposed work plan prior to the meeting At the conclusion of the presentations, the agency representatives were asked to supply oral and subsequently written comments expressing their concerns with the proposed hydropower proJect and the proposed environmental work plan for 1982 Che maJor concerns expressed orally at thi~ meeting are listed below o Were the five reaches selected for Instream Flow Gauging chosen only on the basis of hydrologic Information or was fishery Information also used? 0 Both hydrologic and fisheries data were used to select the number and location of critical reaches Will one year of work be sufficient to accurately assess the Instream flow requirements? One year should be sufficient because of the amount of data gathered In previous hydrologic and fisheries studies that can be compared to our data Also, the IFG model will be verified after the Initial July data are available However, ~f cr~t~cal data def~c~enc~es are ~dent~f~ed, measures w~ll be taken to resolve such def~c~enc~es o If only five critical reaches are chosen for the Instream Flow studies, will that Information be sufficient to assess the Impacts to the entire fishery? 10-6 I ! \ l I \ ~ A ,, I \ I ' I \ \ I I I 0 J 0 ( ......, -~ I { li, I 0 0 I r Because the critical reaches Include the maJor spawning, rearing, and migration areas, and the areas that could potentially be Influenced the most by the proJect, we feel that the data gathered will provide enough Information to assess Impacts In addition, If future studies Indi- cate that more critical reaches are needed, we will consider Including them Will the distribution of age and size classes as well as the Intra-areal movements of JUVeniles and residents be Investigated? Through the diverse nature of the collecting gear and the number of sample Sites, age and size class distribution will be Investigated Local movements of residents and JUve- niles Within the study area Will not be directly addressed, because data collected through other aspects of the program (maintenance of habitats) Will be sufficient to assess proJect Influences on local movements Since the winter low flow periods are a critical time of year, will the winter studies be sufficient to evaluate the effects of altered discharge on the fish populations? At this time we feel that the sampling effort planned for the Winter will be sufficient to assess the effects of altered discharge on the fish populations Local f1sherman and the resource agenc1es are perhaps most concerned about the cumulative effects of the Chakachamna and other Upper Cook Inlet proJects on commerc1al f1sher1es The comment was noted Are the Hab1tat Evaluat1on Procedures be1ng appl1ed and what, 1f any, changes 1n the program are antic1pated? The Hab1tat Evaluat1on Procedures are be1ng appl1ed Only two changes are ant1c1pated 10-7 1) The change ~n hab~tat un~ts over the l~fe of the proJect w~ll not be calculated because the potent~al effects of other nearby developments (Beluga Coal f~elds, t~mber harvest~ng, and offshore o~l develop- ment) cannot be accurately assessed 2) Because the models descr~b~ng the hab~tat preferences of the evaluat~on spec~es are based on a general~zed n~che concept, changes w~ll be made, where necessary, to make the models more appl~cable to the preferences of the spec~es ~n the study area o Are the transm~ss~on l~ne corr~dor and road r~ght-of-ways go~ng to be ~nvest~gated 7 Both w~ll be evaluated by all d~sc~pl~nes after the general routes have been determ~ned o Are any env~ronmental stud~es planned for the mar~ne or ~ntert~dal zone 7 The poss~b~l~ty of spawn~ng, rear~ng, and m~grat~on areas ~n the ~ntert~dal zone w~ll be ~nvest~gated The spec~es compos~t~on and d~str~but~on of b~rds and mammals ~n the ~ntert~dal zone w~ll also be ~nvest~gated No stud~es are planned at th~s t~me for the mar~ne env~ronment o What fac~l~t~es are planned for the coast? 0 At th~s t~me, the only proposed development of the coast w~ll be a dock and an a~rstr~p near Gran~te Po~nt W~ll the results of the 1981 ~nvest~gat~ons be ava~lable for agency rev~ew? 10-8 I' ; ' c__) ' l \ \ \ l I ' -J r- 1 ~\ I Ll I \ / I I 'i L 0 0 0 In January 1982, the results of the envlronmental studles as well as a complete proJect descrlptlon wlll be sent to the agenc1.es Wlll a more detalled 1982 work plan be avallable that descrlbes the functlons that wlll be performed by subcontrac- tors, who the subcontractors are, and what the approxlmate level of effort lS for each sub-task? A new work plan wlll not be prepared However, a llst of subcontractors and thelr obllgatlons wlll be sent to the agencles along wlth a schedule of the approxlmate level of effort apport1.oned to each sub-task Wlll an Agency Task Force approach be lnstlgated to coordl- nate agency lnput to mltlgatlve measures? If the agencles choose that approach, APA, Bechtel, and Woodward-Clyde are wllllng to work Wlth the Task Force When, where, and how many publlc meetlngs are planned? No speclflc tlmes, dates, places, or numbers have been determlned However, due to the speclal lnterest of the people ln Soldotna, one of the meetlngs may be held there The representatlves from the agencles agreed to submlt further wrltten comments after they had revlewed the results of the 1981 lnvestlgatlons and revlewed the prellmlnary proJect deslgns They wlll each submlt comments to thelr supervlsor and one letter from the head of each agency Wlll be submltted to the APA 10-9 10 3.1.1 10.3 2 Response The responses to the quest~ons ra~sed at the meet~ng are set forth ~n the meet~ng notes preced~ng th~s paragraph, ~mmed~ately after each quest~on Correspondence The follow~ng pages d1splay reproduct1ons of corres- pondence rece1ved from the follow1ng agenc1es o u.s. F~sh and W1ldl1fe Serv1ce, March 5, 1982, March 26, 1982 o Alaska Department of F1sh and Game, February 18, 1982 o Nat1onal Mar1ne F1sher1es Serv1ce, February 18, 1982 Th1s correspondence relates to the 1982 work plan wh1ch was d1str~buted to the agenc1es pr1or to the December 11, 1981 meet~ng as well as to the proposed proJect development The comments rece1ved from the f1shery agenc1es 1n these letters were taken under adv1sement and as gu1dance 1n def1n1ng and execut1ng the f~nal 1982 work plan The 1mplementat1on of many of the agenc1es' suggest1ons however, has had to be deferred unt1l later I I I I \ I I I I I ~ I ) I !' l ~ I I I I stud1es. Responses by the Power Author1ty to the letters ! ', from the agenc1es 1mmed1ately follow the letters from each agency I I 10-10 I ' ft \ I I - ! I \ I _~:I ,~, I I, ' ~j I \_ y I I \ ! I \----' U n1ted States Department of the In tenor IN REPLY REFER TO WAES Mr Er~c P Yould Execut1ve D1rector Alaska Power Author1ty FISH AND WILDLIFE SERVICE 1011 E TUDOR RD ANCHORAGE ALASKA 99503 (907) 276 3800 0 5 MAR 1982 333 West 4th Avenuep Su1te 31 Anchoragep Alaska 99501 Re Dear Mr Yould Chakachamna Hydroelectrlc ProJect 1982 1vork Planp Env1ronmental Stud1es Th2s letter transm1ts to the Alaska Power Author1ty (APA) comments and recom- mendahons of the U S F1sh and W1ldllfe Sernce (FWS) relah ve to the 1982 1vork Plan, Env1ronmental Stud1es for the Chakachamna Hydroelectr1c ProJect Our comments are based on a rev1ew of the 1982 Work Plan 1n conJunctlon Wlth a rev1ew of the Chakachamna Hydroelectr1c ProJect Inter1m Report dated November 30, 198lp and forwarded to us on January 9, 1982, and coord1nat1on meet1ngs between APA, ~ts consultant, FWS, the Alaska Department of F1sh and Game (ADF&G), the Nat1onal Mar1ne F1sher1es Serv1ce (NMFS), and other 1nterested I part1es. The FWS apprec2ates the opportun1ty to part1c1pate 1n developlng the b2olog1cal program for the Chakachamna Hydroelectr1c Feas1b1l~ty Study We feel that the 1982 Work Plan has prov~ded an outl~ne for some of the bas1c b1olog2cal stud1es that w1ll be requ1red to address the effects of the Chakachamna HYdroelectrlc ProJect on f1sh and w1ldl1fe resources We are prov1d1ng comments spec1f1c to the 1982 Work Plan to 1dent1fy the 1nformat1on we bel1eve 1s essent1al to 1dent1fy f1sh and w1ldl1fe resources of the proJect area, determ1ne potent1al ~mpact of the proJect upon those resources, evaluate alternat1ves to the pro- posed proJect, and formulate m1t1gat1on/enhancement measures Our comments are as follows GENERAL COMMENTS As presently conce1ved, the scope of stud1es presented 1n the 1982 Work Plan w~ll not prov~de the data necessary to meet the study obJeCt1ves as ~dent1f1ed on Page 1 Thorough 1nteragency coord1nat~on and comprehens1ve plann1ng of b1olog1cal stud1es ~s needed to 1nsure an adequate ~nformat1on base for the preparat1on of env1ronmental exh2b1ts for subm1ttal to the Federal Energy Regulatory Comm1ss1on (FERC) Formal state/federal 1nteragency coord2nat~on can best be 1n1t1ated by appl2cat1on for a FERC prel1m1nary perm1t Advantages 1n apply1ng for a prel1m1nary perm1t 2nclude the early 1dent1f2cat1on of all 1nvolved agency concerns as well as establ1shment of a formal relat1onsh1p w1th 10-11 Page 2 the FERC The ldentlflcatlon of agency concerns early ln the plannlng process can prevent delays ln processlng the appllcatlon for llcense and preparatlon of an Envlronmental Impact Statement (EIS) Under the FERC llcenslng process, the appllcant may be requlred to collect add1t1onal data 1f the envlronmental exh1b1ts are found to be 1nadequate by state and federal resource agenc1es To date, there has been only br1ef reconna1ssance-level f1eld 1nvest1gat1ons conducted late 1n the 1981 f1eld season We understand that fleld stud1es are scheduled to term1nate 1n November 1982 and that, three months later, a feasl- blllty report and FERC l1cense appllcatlon are due Cons1der1ng the complex1ty of the Chakachatna and McArthur R1ver systems, the lack of baslc qualltatlve flshery resource data, and the magn1tude of the potent1al 1mpacts to these resources wh1ch would result from hydroelectrlc development, the approx1mate ten months allocated to f1eld stud1es and three months allocated to the analysls of the results of these stud1es lS 1nsuff1c1ent to adequately assess the effects th1s proJect would have on f1sh and Wlldllfe resources The 1mpact of th1s proposed proJect upon both the Lake Clark Nat1onal Park and the Trad1ng Bay State Game Refuge adds to the complexlty of the assessment A llst of l1terature c1ted should be added to the work plan to fac1l1tate the use of references c1ted Speclflc Comments Env1ronmental Hydrology Reg1me Observat1ons (Page 2) We are pleased w1th the scope of study of th1s sect1on, but quest1on how the reg1me character1st1cs 1dent1f1ed on pages 3 and 4 can be adequately assessed 1n a s1ngle rema1n1ng f1eld season As related to salmon1d spawn1ng hab1tat, a more deta1led d1scuss1on 1s needed to show how character1st1cs of Slde channels and h1gh water channels, tr1butary character1st1cs, and bed scour, degradat1on, and aggradat1on w1th1n the Chakachatna and McArthur R1ver systems w1ll be assessed The t1m1ng and level of fleld effort to accompl1sh th1s need to be 1dent1f1ed. The use of aer1al photographs should not be used as a subst1tute for ground-level observat1ons 1ncorporat1ng phys1cal parameter measurements The eros1on stud1es proposed for the lake tr1butar1es need to be expla1ned 1n further deta1l Hydrology (Page 4) We feel that rel1able flow data 1s obta1nable, 1n llght of the 13 years of record by USGS, for the Chakachatna R1ver. We are concerned, however, that representat1ve flows for the McArthur R1ver may not be An assessment of groundwater lnflow through s1de channels and sloughs, aga1n 1n relat1on to salmon1d spawn1ng hab1tat, 1s needed The evaluatlon of w1nter flow charac- ter1st1cs needs expans1on. The expans1on should 1nclude the methodolog1es and study s1te locat1ons as well as an assessment of the correlat1on between these s1tes and f1sh over-w1nter1ng hab1tat 10-12 I ~ I I \ I I I ) It I I I_ l I I I ~ I I I ' I I I \ ( i L l \ 'I \:~ I r I I I ~J I f 1_ I I Page 3 We are concerned that the level of effort needed to assess the flow requ2rements for the ma2ntenance of the Noaukta Slough and Trad2ng Bay wetlands w2ll not oe met Thls portlon of the hydrology program needs expanson Pdd2t2onally, a water-qual2ty program needs to be developed and the t2m2ng and level of effort 2dent2f2ed Instream Flow Invest2gat2ons (Page 5) We have contacted the FWS Cooperat2ve Instream Flow Group (CIFG), Ft Coll2ns, Colorado, for lnput lnto th2s port2on of the 1982 ''fork Plan Thelr comments, once rece2ved, Wlll be forwarded to you for cons2derat2on 2nto your study des2gn We are pleased that the IFG Incremental Methodology Wlll be appl2ed However, there appears to be a l2m2ted data base to support the select2on of the study s2tes 2dent2f2ed 2n the study plan Prlor to appl2cat2on of the 2ncremental methodology, a qual2tat2ve understand2ng of morpholog2c, hydraul2c, and blologlc character2st2cs of the two r2vers must be obta2ned The seasonal dlstrlbutlon and hab2tat ut2l2zat2on of flsh spec2es as well as the seasonal flow patterns and channel structure must be known before study s2tes can be selected. There are a number of anadromous and res2dent f2sh 2n thls system A good qual2tat2ve understandlng of relat2ve abundance, seasonal hab2tat requ2rements and d2strlbut2on should be obta2ned for all key spec2es However, for appll- catlon of the lncremental methodology, and development of habltat su2tab2l2ty crlterla we suggest that target spec2es be selected 2n consultatlon Wlth state/federal resource agencles for deta2led analys2s We are concerned about the tlmlng of the 2nstream flow stud2es These stud2es are generally conducted ln two phases. Dur2ng phase I a qual2tat2ve under- standlng of the b2olog2c, hydraul2c, and morpholog2c character2st2cs of a system 2s obtalned. From thls 2nformat2on a phase II study plan lS formulated The r2ver lS subdlvlded 2nto relat2vely homogenous segments and study s2tes are selected for deta2led analys2s Relatlonshlps of ex2st2ng f2shery resources are rev2ewed and target spec2es are selected for use 2n the analysls Phase II 2ncludes the collect2on of hydraullc cal2brat2on data, computer modellng of study sltes, development of hab2tat su2tab2l2ty cr2ter2a and analys2s of pro- Jected effect S2nce the tasks 2n phase II are dependent on the results of phase I stud2es, we do not bel2eve these two phases can be undertaken concur- rently. We refer you to An Assessment of Envlronmental Effects of Construct2on and Operat2on of the Proposed Terror Lake HYdroelectr2c Faclllty, Kodlak, Alaska, Instream Flow Stud2es, prepared by Arct2c Env2ronmental Informatlon and Data Center, Un2vers2ty of Alaska, March 1981, as a good example of an Alaskan appl2cat2on of 2nstream flow techn2ques whlch requ2red two full fleld seasons to obtaln. F2nally, there arena data to substant2ate the 19% prov2slonal reservat2on of the average annual lnflow to Chakachamna Lake, as presented ln the Inter2m Report and derlved by the Montana Method, to meet the 2nstream flow requ2rements for f2shery resources ln the Chakachatna R2ver Because of the apparent 2mportance of s2de channel hab2tats, the Montana Method may not be appropr2ate for appl2ca- t2on to the Chakachatna Rlver The 2nstantaneous and seasonal flows necessary to sustaln thls resource should em2nate from the 2nstream flow stud2es planned 10-13 Page 4 Aquat1c B1ology Macro1nvertebrates (Page 7) Wh2le the effort presented 2n thls sect2on lS commendable, we cons2der the forage stud1es to be of lesser pr2or2ty than the flsh studles Accord2ngly, the prlmary obJeCtlve should be conductlng adequate flsh stud2es The t2m2ng and study s2te locat2ons lnvolved 2n the macro2nvertebrate 1nvest2gat2ons should be 2dent2f2ed 2n the study plan. F1sh (Page 9) In general, we feel that the f2sh studles presented 1n th1s sect2on are one of the stronger port2ons of the overall 1982 Work Plan Our maJor concern lS that one f2eld season Wlll not be adequate to gather the necessary f2eld data to adequately assess spec1es presence, compos1t2on, and d1str2but2on, spawn2ng hab2tat, m2gratory pathways, JUVenlle rear2ng hab2tat, and general habltat ut1l1zat1on Th1s may be further compl1cated by the fact that 1982 represents an even-year p1nk salmon run 1n Cook Inlet and returns could be substant1al The use of hydroacoust1cs 1n 1dent1fy1ng these parameters needs further explanat1on and expans1on We suggest the poss1ble use of rad1o-tagg1ng techn2ques to further 1dent1fy m1gratory pathways and spawn2ng hab1tats The FWS, F1sher1es Research Center, Alaska F1eld Stat1on, has successfully appl1ed th1s techn1que 1n ch1nook salmon 1nvest1gat1ons on the Kena1 R1ver Add1t1onally, the Alaska Department of F1sh and Game has appl1ed the techn1que to assess chum, coho, and ch1nook salmon hab1tat 1n the Sus1tna R2ver It 1s part2cularly appl2cable 1n systems where VlSlb1l1ty lS a l1m1t2ng factor I Spawn1ng (Page 9) It 1s necessary to 1dent1fy the relat1ve 1mportance of d1fferent types of spawn1ng hab1tats throughout the Chakachatna and McArthur R1vers and the1r relat1ve contr1but1on to the total product1on of the system We are 1nterested 1n the relat2ve 2mportance between ma1nstem and s1de channel hab1tats and an evaluat1on of 1ncubat1on success 1n these hab1tats. We are part1cularly 1nterested 1n the s1de channel hab1tat 1n the Chakachatna R1ver wh1ch may be affected by reduced flows. Ident1f1cat1on of spawn1ng hab1tat 1n Chakachamna and Ken1buna Lakes and the1r tr1butar1es 1s needed M1grat1on (Page 11) The assessment of m1gratory pathways should be focused on those areas to be 1mpacted by the proJect It 1s 1mportant to 1dent1fy the relat1ve 1mportance of the var1ous m1gratory routes A more deta1led d1scuss1on of the sampl1ng s1te locat1ons and t1m1ng 1nvolved 1n th1s effort 1s needed Hab1tat Ut1l1zat1on (Page 12) We feel that the adequate assessment of over- w1nter1ng hab1tat 1s cr1t1cal 1n regard to m1n1mum flow requ1rements A descr1pt1on of how and where th1s Wlll be accompl1shed 1s lack1ng 1n th1s sect1on Commun1ty Analyses (Page 13) A further explanat1on of what th1s sect1on w1ll contr1bute to the overall analys1s of f1shery resources 1n the Chakachatna and McArthur R1ver systems lS needed Impact Assessments (Page 13) It 1s essent1al for the FERC perm1t appl1cat1on to 1nclude a comprehens1ve m1t1gat1on plan developed 1n cons1derat1on of but not l1m1ted to the folloWlng 1 Develop1ng f1sh pathways at the mouth of 10-14 ~ 0 I I I I I I I ( I I J I I I I I J I I j I \ I L I I I I I I l \ I \ - \ I I (--. I I I '-I II Chakachamna Lake to ma2nta2n outm2grat2on and adult escapement, 2 use of art2f2c2al ~pawn2ng channels to mltlgate the loss of spawn2ng hab2tat, 3 malntenance of m2grat2onal pathways to the tr2butar2es of Chakachamna and Ken2buna Lakes after lake drawdown, 4 mltlgatlon for the loss of spawn2ng hab2tat along the lakeshores Temperature The 1982 Work Plan lacks completely a sect2on on the assessment of temperature reg2mes 2n the r2ver and lake systems We suggest a program be developed to address thls 2ssue and that the 2mpacts of altered temperature reg2mes be assessed A temperature model needs to be prepared W2ldl2fe Blology (Page 14) We are pleased that a HEP analys2s lS proposed As an 2ntegral part of HEP, we encourage you to make use of a state/federal 2nteragency team to select 2nd2cator specles and techn2cally ass2st 2n the appl2cat2on of HEP In so do2ng you Wlll lnsure that the perspect2ves of all agencles are lncluded 2n the process, thus 2ncreas2ng the acceptab2l2ty of the product One 2nd2cator spec2es, prel2m2nar2ly chosen, the tule goose, has never been found to nest ln the area Its usefulness as an 2nd2cator spec2es 2s quest2onable We suggest that the proJect boundary be reevaluated to encompass not only the total land and water areas where d2rect 2mpacts could occur, but where secondary 2mpacts due to human encroachment and construct2on act2v2t2es result2ng 2n w2ldl2fe d2splacement are expected Spec2f2cally, proposed construct2on camp s2tes, access road al2gnments, transm2ss2on corr2dor al2gnments, proposed a2rstr2ps, and t2dewater fac2l2t2es need to be assessed closely for potent2al 2mpacts to w2ldl2fe m2grat2on routes as well as loss of potent2ally 2mportant feed2ng and cover hab2tat types We would l2ke to see a compar2son, based on quant2f2ed I hab2tat un2ts, of the relat2ve 2mpacts of alternat2ve access routes and alternat2ve proJect des2gns on w2ldl2fe resources The mapp2ng of vegetat2ve hab2tat types should cover the ent2re area of pro- Ject 2nfluence to a scale of l 2nch per m2le. The scale should be expanded to 4 2nches per m2le 2n areas of s2gn2f2cant alterat2on We recommend th2s expanded scale be used to map all r2par2an and wetland hab2tat types We are part2cularly concerned about potent2al 2mpacts to the trumpeter swan popula- t2on 2n the proJect ~rea (143 swans reported 2n 1980) Potent2al confl2cts between m2grat2on routes and transm2ss2on corr2dor al2gnments for swans and other waterfowl spec2es need to be 2dent2f2ed early Add2t2onally, potent2al 2mpacts to nest2ng pa2rs of swans should be exam2ned carefully. Other 2mportant cons2derat2ons 2nclude the 2dent2f2cat2on of bear denn2ng s2tes and moose and car2bou calv2ng grounds wh2ch may be w2th2n the proJect boundary Part2cular attent2on should be focused on f2eld 2nvest2gatons of r2par2an hab2tat and the extens2ve wetland complex of Trad2ng Bay 2n regard to the h2gh use by w2ldl2fe these areas rece2ve Wh2le the W2ldl2fe B2ology port2on of the 1982 Work Plan 2dent2f2es these concerns 2n general, 2t falls to adequately descr2be the t2m2ng and level of effort to be appl2ed to comprehens2vely evaluate them Add2t2onally, we are concerned about the d2sposal s2te locat2on for talus mater2al from power tunnel excavat2on and the locat2on of a barge fac2l2ty 2n the t2delands of Trad2ng Bay Alternat2ve locat2ons for these proJect features need to be 2dent2f2ed and relat2ve 2mpacts assessed il.0-15 \ Endangered Spec1es As requ1red by the Endangered Spec1es Act (87 Stat 884, as a~ended), the FERC, or the1r des1gnee, should formally request a l1st of threatened or endangered spec1es from th1s agency If the l1st 1nd1cates that these spec1es are present 1n the proJect area, FERC 1s requ1red under Sect1on 7(c) to con- duct a B1olog1cal Assessment~ Th1s assessment would 1dent1fy any l1sted or proposed threatened or endangered spec1es and d1scuss potent1al prOJect related 1mpacts The assessment 1s to be completed w1th1n 180 days after rece1pt of the off1c1al l1st, unless a t1me extens1on 1s mutually agreed upon No contract for phys1cal construct1on may be entered 1nto and no phys1cal construct1on may beg1n unt1l the B1olog1cal Assessment 1s completed If the conclus1ons drawn from the B1olog1cal Assessment 1nd1cate that endan- gered or threatened spec1es are l1kely to be affected by the construct1on proJect, FERC 1s requ1red by Sect1on 7(a) to request formal consultat1on Conclus1on and Recommendat1ons The results of the 1982 f1eld 1nvest1gat1ons w1ll prov1de some of the basel1ne data necessary for 1mpact assessment. We feel th1s data w1ll be qual1tat1ve 1n nature w1th ref1nement poss1ble only after add1t1onal study and analys1s. The compressed t1me-frame of the feas1b1l1ty study as currently proposed, however, does not allow such analys1s To date, there has been l1ttle effort g1ven to the development of 1mpact assessment and m1t1gat1on strateg1es As plann1ng and stud1es cont1nue, we feel a more comprehens1ve and formal coor- d1nat1on process should be establ1shed and 1mplemented between APA, the con- sultant, and the resource agenc1es Also, there has yet to be developed a forum for publ1c 1nput It 1s obv1ous that there has not been adequate t1me allocated for env1ronmental stud1es to be conducted wh1ch are comensurate w1th the magn1tude and complex1ty of the potent1al 1mpacts assoc1ated w1th the Chakachamna Hydroelectr1c ProJect. Accord1ngly, we recommend l That an Interagency Task Force be establ1shed 1n order to techn1cally ass1st 1n the terrestr1al hab1tat and 1nstream flow analyses, coord1nate and rev1ew the results of further enVlronmental stud1es, assess 1mpacts, and formulate m1t1gat1on proposals, 2. that the APA apply for a FERC prel1m1nary perm1t to 1n1t1ate formal 1nteragency coord1nat1on, 3 4 5 that the t1me-frame for the scope of the env1ronmental stud1es assoc1ated w1th the feas1b1l1ty study be expanded and that the 1982 f1eld season be ut1l1zed to collect adequate qual1tat1ve basel1ne b1olog1cal data of suff1c1ent scope, that a rev1sed Work Plan for env1ronmental stud~es, based on the expanded t1me-frame, be formulated and rev1ewed by the Interagency Task Force, that appropr1ate procedures be developed for coord1nat1on between resource agenc1es and the APA to 1nclude coord1nat1on meet1ngs w1th suff1c1ent lead t1me to allow for 1nformat1on exchange and proJect rev1ew, and 10-16 I ( I I I I I l I I I _j I I I \~ I l I 'I \ _J I J I I I I I ~ 1-----, I I I ,I l ~' I l J r- L I _'I I { I L ~ I I • I I I 1 I c ~' Ll I ~ L_ lJ Page 7 6 that a forum for mean~ngful publ~c ~nput be establ~shed F~nally, we can see no advantage ~n present~ng an appl~cat~on to FERC, wh~ch w~ll be rev~ewed by FWS, that does not conta~n an ade~uate assessment of proJect ~mpacts to f~sh and w~ldl~fe resources and a comprehens~ve m~t~gat~on plan Subm~ss~on of env~ronmental exh~b~ts under such a compressed t~me-frame can only h~nder the des~gn~ng of an env~ronmentally sound prOJect Accord~ngly, the FWS recommends the l~cense appl~cat~on be delayed unt~l suff~c~ent b~olog~cal data are ava~lable We look forward to cont~nu~ng to work closely w~th the APA ~n the future to develop and ~mplement a mutually acceptable feas~b~l~ty study We encourage your consultants to now contact our Western Alaska Ecolog~cal Serv~ces F~eld Off~ce for techn~cal ass~stance ~n plann~ng for the appl~cat~on of HEP and Instream Flow methodology cc FWS-ROES, WAES, CIFG ADF&G, ID1FS, EPA, ELM, USGS, NPS, ADEC, ADNR M~ke Joyce, Woodward-Clyde FERC, Wash~ngton, D C 10-17 Uruted States Department of the Intenor IN RE"L Y REFER TO WAES Mr Er~c Yould, Execut~ve D~rector Alaska Power Author~ty 334 W 4th Avenue Anchorage, Alaska 99501 FISH AND WILDLIFE SERVICE Western Alaska Ecolog~cal Serv~ces 733 W 4th Avenue, Su~te 101 Anchorage, Alaska 99501 (907) 271-4575 ~)t,-.... i{ Re Chakachamna Hydroelectr~c ProJect, 1982 Work Plan, Env~ronmental Stud~es Dear Mr Yould Th~s letter transm~ts to the Alaska Power Author~ty (APA) comments and recom- mendat~ons of the U.S F~sh and W~ldl~fe Serv~ce (FWS) Instream Flow and Aquat~c Systems Group, Fort Coll~ns, Colorado, relat~ve to the 1982 Work Plan, Env~ronmental Stud~es for the Chakachamna Hydroelectr~c ProJect Prev~ous FWS comments relat~ve to the 1982 Work Plan, Env~ronmental Stud~es, were forwarded to you on Marah 5, 1982 The enclosed comments are spec~f~c to the ~nstream flow and hydrolog~c aspects of the 1982 Work Plan I We look forward to cont~nu~ng to work closely w~th the APA ~n the future to develop and ~mplement a mutually acceptable feas~b~l~ty study We encourage your consultants to contact our Western Alaska Ecolog~cal Serv~ces F~eld Off~ce for technlcal ass~stance ~n plann~ng for the appl~cat~on of Instream Flow methodology for th~s proJect Enclosure cc FWS-ROES, WAES, CIFG ADF&G, NMFS, EPA, BLM, USGS, NPS M~ke Joyce-Woodward-Clyde FERC-WDC s~ncerely, F~eld Superv~sor 1e-1a I I -I I I I I I I t I l \ I , I ' L (r I I I ~ I '~ I L -" I l I Untted Statc.s l)cp,lrtment of the In tenor Mr Dave ferrell ~l\11 -\I'll> \\II lliiH C.,fRVIC ~ OFFICE OF BIOLOGICAL SERVICES We~rcrn Energy & land U~e Te11m Drake Cr(.eb1de Budd1ng 2625 Redwmg Ro11d Fori Coll1n. Colorado 80526 Instream Flow and Aquat~c Systems Group March 12, 1982 ~estern Alaska Ecolog1cal Serv1ces 733 W 4th Avenue, Su1te 101 Archorage, AK 99501 Dc1r Mr Ferrell rrc 206 As per your letter of february 1, 1982 and your phone conversat1ons w1tn Cl<:nr Stalnaker, I have rev1ewed the Inter~m Report on Chakacharrna Hydroelectr1c ProJect and the work plan for the env1ronmental stud1e~ Hy 1n~t1al react1on 1s that there 1s not enough 1nformat1on 1n the env1ronmental work plan on wh~ch to base any comments for 1nstancc, there 1s no 1nformat1on on water temperature aspects 1n the 1ntcr1m report and no mentlon of water temperature ~n the env11onment~l work plan I w1ll return to the work plan later l1rst, let us loo~ at the 1nter1m report, the purpose of the report was to prov1de a prel1m1nary evaluat~on of the proposed pro1ect Consequently, all elements of the proposed proJect could change before construct1on The Tennett (Montana) method was used to obta1n some ~dea of the 1nstrean flows wh1ch are needed 1n the var1ous streams It 1s 1nterest1ng that the Bechtel staff have assumed r1vers of the northern great pla1ns are representat1ve of glac1al r1vers 1n Alaska It 1s not 1nappropr1ate to use a techn1que that uses a fract~on of the natural flow 1n the stream as an 1n1t1al est1mat1on of the 1nstream flow needs The ftact1on should be developed for s1m1lar geomorphology and b1olog1cal cond1t1ons In the case of the Ch.Jir"Jch•mn1 proJect, d>ta for ro'1St1l nrC'gon, \'1slnngton, 11rd !It lLlt II (tdumld 1 'II wlll 11 Allt•tku, u•uld It IVL bt<.ll u ul lo dLVLI<•!• the hydrograph mult1pl~ers to est1mate the 1nstrenm flow needs If 1t 1s assumed all the 1nformation ava1lable about the f~shcrtcs .1spect of the proJect area are covered ~n the rcrort, then there LS 1 maJor lack of bas1c data on the ex1st1ng cond1t1ons wh1ch, 1n my op1n1on, 10-19 m'1h.c.., It difficult to devLlop 1 work pl11' for envlronmL!lt>l studies At tfn, po1nt, I can onlv outl1nc d fc\-' of my m110t concerns, these arc l !here tppeJrs to be no Llemcnt 1n the \.Jorh. plan to ~tudy thL streJms dhove the. l1h.c-they should be studied 2 3 4 The channel streams flowing Into the l1ke are l1h.ely to change as a result of lower1ng the lake level -thls aspect 1s very 1mportant and must be stud1ed The Chakachatna r1ver channels downstreaM of the lake and the McArthur r1ver channels arc al~ost certain to change as a result of the proJect, '1n engineer1ng study 1s requ1red S What hab1tat cr1ter1a are to be used to relate the f1sh spec1es to the phys1cal habitat, arc new criteild data to be collected? 6 It 1s d1ff1cult for me to comment on the s1te select1on because of the lack of 1nformation but the proposed sites do not 1nclude the channels below Noaukta Slough I suspect the proposed proJect w1ll have an 1mpact on the channels below "l'oaukta Slough I would l1ke to know JUSt what "cornnun1ty analys1s" 1s as descr1bed on page 13 of the work plan and how 1t f1ts 1n w1th other elements of the 'ork. plan I If I were do1ng the proJect plann1ng, I would cons1der select1ng only a few s1tes th1s year for 1nstream flow stud1es and spend most of the effort obtain1ng a cledr p1cture of the system The follow1ng year would be used for the more deta1led stud1es Th1s way I would soon have 1nformat1on on the 1nstream flow needs on wn1ch to base future plann1ng stud1es and have the type of Informat1on needed for the f1nal analys1s some t1me later I hope these comments are of use to usc -unfortun1tely I can do l1ttle more because of the lack of 1nfornat1on 1'1 the environmental ~ark plan ~1ncercly, Robert H1lhous Hydrolog1st 10-20 -1 j I I I I I I \ I I i I I I I I I j \, I I 1 I I I r-( \ I I I I_ (~ I I I I ~ J I (-, I I ~- I I I ,---1 I ' ' -, \ I I ( I \ L~ I [: 0 /"\ I ( l __ } I I I ~ 334 WEST 5th AVENUE ANCHORAGE, ALASKA 99501 RECEIVED DEC 2 1982 R. T LODER Mr Ke1th Schre1ner Reg1onal D1rector U.S F1sh & W1ldl1fe Serv1ces 1011 East Tudor Road Anchorage, Alaska ~503 Dear Mr y(rf.n~; November 26, 1982 Phone (907) 2n-7641 (907) 276-0001 Please reference your agency•s letter of March 5, 1982, concern1ng Chakachamna Hydroelectr1c ProJect 1982 Work Plan, Env1ronmental Stud1es The Alaska Power Author1ty apprec1ates the deta1led comments your agency has prov1ded, but due to severe budget restra1nts we have not yet been able to 1mplement most of those The Power Author1ty through our consultant, Bechtel/Woodward-Clyde, has collected f1shery data dur1ng th1s past summer and fall Your agency personnel v1s1ted the proposed proJect area wh1le Woodward-Clyde was actually collect1ng th1s data dur1ng August 1982 We would l1ke to 1nv1te you and your staff to a meet1ng at 9 30 AM on December 9, 1982, 1n the new Feder~l Bu1ld1ng, Nat1onal Weather Serv1ce, 5th floor, East Conference Room. The purpose of the meet1ng w1ll be to present 1nformat1on collected dur1ng the summer anc fall and answer quest1ons on an 1nformal bas1s concern1ng the resource 1n the area I have attached an agenda for the meet1ng We have requested add1t1onal fund1ng for the FY 84 budget year 1n order to complete the feas1b1l1ty study Once leg1slat1ve approval has been acqu1red, a new work plan for env1ronmental stud1es w1ll be developed tak1ng 1nto account concerns prev1ously expressed by your aqency and others It 1s our 1ntent to coord1nate th1s plan w1th the concerned agenc1es Thank you for your cont1nued part1c1pat1on 1n our plann1ng act1v1t1es cc Robert Loder, Bechtel Wayne L1fton, Woodward-Clyde Kenneth Plumb, FERC z:ely~ Er1c P Yould Execut1ve D1rector Gary Stackhouse, U S F1sh & W1ldl1fe Serv1ce Lenny Cor1n, U.S F1sh & W1ldl1fe Serv1ce Attachment Agenda 10-21 , r , ATTACHMENT A TENTATIVE AGENDA FOR DECEMBER 9 MEETING Chakachamna Hydroelectric ProJeCt I Open~ng Remarks Purpose of Meeting Provide Background to New Personnel To Rece~ve Agency Input To Keep Agenc~es Informed II Descr~pt~on of ProJect Er~c Marcheg~an~/Bob Loder Engineer~ng Stud~es to Date F~sh Passage Fac~l~ty Concepts III Env~ronmental Stud~es Wayne L~fton FY 1982 FY 1983 -scope, general obJect~ves Hydrology L Rundqu~st Aquat~c B~ology Wayne L~fton l0-22 1 !' l-! I~ 'J r I [ \-\ t I !J :J I I i_) il ~ J I I r \, ~1 r I I l I' l~ r, 1 : w DlEP~RT~lE~T ®IF lfi~&U -\ ~D G \Will-~ OFFICE OF THE COMMISSIONER February 18, 1982 Alaska Power Author1ty 334 W. 5th Avenue Anchorage, Alaska 99501 Attent1on Mr Er1c P Yould, Execut1ve D1rector Gentlemen --y JAYS HAMJIIONO GOVERJlOR PO BOX 32000 JUNEAU AJ.,MK4A19.9.802 PHONE 4btl-UU r • .:~EI\:L..u M.A.,q 11982 7US<A POWER AUTHORITY Re 1982 Chakachamna Hydroelectr1c ProJect Study Plan Rev,ew, Inter1m Report Eng1neer1ng and Geolog1cal Stud1es (November 1981), Woodward-Clyde Env1ronmental Study Work Plan (December 1981) The Alaska Department of F1sh and Game has rev1ewed the proposed 1982 Chakachamna Hydro Study Plan and subm1ts the follow1ng comments 1982 Env1ronmental Study Work Plan We are concerned that the rema1n1ng one year of study may prove to be 1nsuff1c1ent as very l1ttle 1s currently known about the f1sh and w1ldl1fe resources w1th1n the proJect area In add1t1on, the study plan does not spec1fy the effort devoted to each task or expected sequence of events and from all appearances the 1982 effort looks to be an overly amb1t1ous undertak1ng As we have sa1d 1n the past, we are w1ll1ng to prov1de spec1f1c d1rect1on towards development of stud1es 1f you des1re our ass1stance Please f1nd com~ents spec1f1c to port1ons of the 1982 Study Plan enclosed In add1t1on, please feel free to contact us 1f you have any quest1ons or comments S1 ncerely, [', (\ -. ~~·~ ~koog ( . ) ~-ITinlSSlOner ~ Enclosure I) L~ I i I I .J cc· C Yanagawa R Andrews R Red1ck L Trasky S Pennoyer R Somerv1lle R Logan A K1 ngsbury S E1de D Da1sy R Rays J Fall 10-23 . .l.R 1 1982 ALASKA POWER AUTHORilY 10 1 Eng1neer1ng Stud1es Para 1 Eng1neer1ng stud1es should also address development of structures to reduce or el1m1nate f1sh entra1nment 1n the power tunnel or turb1nes If elevated thermal reg1mes are ant1c1pated, mult1level 1ntakes for both water d1verted for generat1on and that to prov1de 1nstream flows should be cons1dered 10 1 1 Hydrolog1cal Stud1es Para 1 In add1t1on to synthes1z1ng Chakachamna Lake outflow data, we bel1eve 1t necessary to determ1ne the percentage of flow 1n the Chakachatna system contr1buted from tr1butary streams, wetlands, and groundwater w1th respect to spec1f1c stream reaches Th1s w1ll reveal the s1gn1f1cance of lake outflow regulat1on 1n reaches where lowered flows may l1m1t hab1tat It would be w1se to analyze the McArthur system 1n much the same manner but w1th respect to augmented flows Flow augmentat1on may result 1n morpholog1cal changes, changes 1n hab1tat su1tab1l1ty and poss1ble thermal effects Para 2 10-2 4 I t ' J I I -J j \ I_ r \ I ~ I r- \ I I 4 - ,- I L) ( I I I I __ ! I I < I , L.J I I I I ) I In add1t1on to mak1ng pred1ct1ons w1th respect to Chakachamna Lake thermal reg1mes, 1t w1ll also be necessary to pred1ct changes 1n thermal reg1mes (wh1ch would affect salmon1d 1ncubat1on rates) 1n both McArthur R1ver and Chakachatna R1ver Both systems have reaches 1n wh1ch spawn1ng occurs that w1ll be affected by lake releases or power d1vers1ons We suggest that record1ng thermographs be placed 1n stream reaches where spawn1ng m1ght be 1mpacted Th1s 1nformat1on along w1th Chakachamna Lake thermal model1ng, meteorolog1cal data, and hydrolog1cal data can be used 1n a pred1ct1ve stream thermal model 10 1 3 Reservo1r and F1sh Passage Fac1l1t1es Para 1 In add1t1on to pass1ng f1sh 1n and out of Chakachamna Lake, prov1s1ons must be developed to allow f1sh to m1grate 1n and out of tr1butar1es to the lake It appears that dur1ng operat1on, the lake water surface elevat1on w1ll never reach currently ex1st1ng levels and may drop 1n excess of one hundred feet below ex1st1ng levels Th1s w1ll effect1vely 1solate tr1butar1es w1th respect to f1sh m1grat1ons 10 1 4 Power Intake and Tunnel Para 1 Cons1derat1on should be g1ven to des1gn these features to prevent entra1nment of f1sh 10-2 5 10 1 5 Underground Powerhouse Complex Para 1 S1nce the ta1lrace d1scharge w1ll be located 1n an 1dent1f1ed spawn1ng area, 1t should be des1gned to prevent hab1tat degradat1on It may even be poss1ble to des1gn th1s feature to 1ncrease the quant1ty of spawn1ng hab1tat ava1lable and help to offset hab1tat losses elsewhere 10 1 6 Transm1ss1on L1ne and Submar1ne Cable Cross1ng Para 1 Al1gnment select1on and construct1on log1st1cs should be coord1nated w1th the env1ronmental effort to determ1ne the least detr1mental alternatlVe 10 1 7 Access Roads and Construct1on Fac1l1t1es Para 1 Camps1te select1on, road al1gnments select1on, and construct1on should be coord1nated w1th the env1ronmental effort to determ1ne the least detr1mental alternat1ves 10 1 8 Cost Est1mates and Construct1on Schedule 10-2 6 I I I I ' r I I I I I I I J I I ) ' ) I '-I I J I I ' r \ L 1 I \_ I I I J ~ I -, I I I I r ' I I ,_ I~ I Para 1 Construct1on schedul1ng should str1ve to m1n1m1ze env1ronmental 1mpacts by avo1d1ng d1sturbances to f1sh and w1ldl1fe dur1ng sens1t1ve per1ods (spawn1ng, calv1ng, etc ) 1982 Work Plan -Env1ronmental Stud1es, Woodward-Clyde Consultants, December 8, 1982 ENVIRONMENTAL HYDROLOGY Reg1me Observat1ons Para 1 W1ll these reg1me observat1ons ult1mately result 1n a deta1led pred1ct1on of potent1al morpholog1cal and sed1mentat1on changes arr1ved at through model1ng or w1ll pred1ct1ons be subJect1ve 1n nature? Hydrology Para 1 What 1s the rat1onale for those locat1ons? Have they been chosen w1th respect to 1nflux of tr1butary waters, channel conf1gurat1on, f1sh hab1tat, etc ? 10-2 7 W1ll the gauges be operat1onal for more than one year (1982) or at least one water year? W1ll synthet1c data be developed for these gages whose per1od of record equals that used to determ1ne generat1ng capac1ty, reservo1r operat1on, etc ? Para 3 W1ll any attempt be made to quant1tat1vely assess the s1gn1f1cance of the selected wetlands? In add1t1on to the above quest1ons, we are concerned that hydrolog1cal stud1es of the scope necessary to prov1de an adequate assessment of hydrolog1c-hydraul1c 1mpacts cannot be completed dur1ng the 1982 season We assume that the gauge network has not been 1nstalled at th1s t1me nor have transects been located or surveyed If these tasks are accompl1shed th1s spr1ng and summer, the stud1es w1ll have to be Pxtended t1ll at least summer 1983 to get one water year of data and that 1s a very m1n1mal amount Instream Flow Invest1gat1ons Para 1 Are the f1ve study s1tes cons1dered representat1ve or cr1t1cal reaches? It 1s our understand1ng that the cr1t1cal reach approach should be 10-2 8 I I I I I I I I I ' I I I I I~ I 1 I I ,_ 0 I I _r ! I L I I I L I Para appl1ed to reaches whose phys1cal or chem1cal character1st1cs l1m1t the f1shery resource W1th the current knowledge we have of these systems, we suspect that the s1tes should be treated as representat1ve reaches w1th the poss1ble except1on of Chakachatna Canyon wh1ch could be a l1m1t1ng factor w1th respect to m1grat1ons 3 W1th respect to the locat1on of the transects, 1t 1s our understand1ng ( that two cons1derat1ons are paramount 1) a r1g1d channel, and 2) b1olog1cal pert1nency Changes 1n channel shape and whether the locat1on 1s at a hydraul1c control are secondary cons1derat1ons In add1t1on, 1t would be advantageous to have a resource 1nteragency team rev1ew transect select1on Off1ce Analys1s W1ll the bed and bank eros1on analys1s of the McArthur R1ver be a subJeCtlve effort or w1ll 1t 1nvolve use of a sed1ment transport model The analys1s should be appl1ed to Chakachatna R1ver also Operat1on of the proJect w1ll attenuate peak events wh1ch probably move great amounts of sed1ment through the system W1thout these events, there may be s1gn1f1cant morpholog1cal changes W1th respect to the 1nstream flow 1nvest1gat1ons, although not spec1f1ed 1n the study plan, we assume that the IFG-3 model w1ll be 10-29 used to determ1ne we1ghted usable area (WUA) once hab1tat su1tab1l1ty curves have been developed AQUATIC BIOLOGY Macro1nvertebrates How w1ll 1mpacts to macro1nvertebrates be pred1cted? F1sh Para 1 W1ll th1s character1zat1on and quant1f1cat1on of hab1tat effort be co1nc1dent w1th the 1nstream flow effort? Spawn1ng Para 1 If spawn1ng areas have yet conclus1vely 1dent1f1ed, m1ght 1t not be premature to have already selected IFG methodology study s1tes wh1ch are to be representat1ve of spawn1ng areas? Perta1n1ng to the statement that hydro-acoust1c techn1ques w1ll be tested to est1mate spawn1ng dens1ty, 1f th1s techn1que proves 10-30 \ I I I _) I ) l_ l I I 1 l '~ ) I I I \ I I I I I - ' I I ) ' l~ < I '-\ \ I I I J I I I LJ I I l ~ I ' I L successful, w1ll a full scale program be started? what w1ll the program 1nvolve and who w1ll be contracted to conduct 1t? Para 9 We bel1eve that record1ng thermographs would be 1nstalled 1n selected spawn1ng areas to prov1de add1t1onal data needed to determ1ne 1f detr1mental thermal 1mpacts w1ll result Temperature probes should be 1nstalled to record temperatures of both surface and 1ntragravel flows Para 10 & 11 Are m1grat1on pathways addressed through the IFG methodology 1n a representat1ve or cr1t1cal reach study s1te? W1th respect to out-m1grant mon1tor1ng, properly des1gned, th1s program could 1nd1rectly enumerate smolts and prov1de one way of quant1fy1ng the contr1but1on of the McArthur and Chakachamna systems to the Cook Inlet f~sher1es to establ1sh levels of m1t1gat1on necessary The Department currently conducts a smolt out-m1grant study on the Kas1lof R1ver that could serve as a model for the Chakachamna program Hab1tat Ut1l1zat1on Para 4 l0-31 As ment1oned earl1er, 1t would be w1se to rev1ew establ1shment of proposed hab1tat transects w1th an 1nteragency team F1sh Populat1ons Para 1 If 1t becomes apparent that the proJect w1ll s1gn1f1cantly 1mpact the f1sher1es resources of these systems, 1t would be w1se to cont1nue f1sh populat1on stud1es for several years Otherw1se there w1ll be no data regard1ng numbers of f1sh on wh1ch to base levels of requ1red m1t1gat1on Impact Assessment Para 2 We suggest that an 1nteragency team be establ1shed to propose and rev1ew m1t1gat1on measures and to 1dent1fy areas where further study m1ght be 1nd1cated WILDLIFE BIOLOGY W1ldl1fe Para 2 10-32 I I I I I I ) I 1 I I -I I I I ( ---' -, I I Lli I I I I _j I I I I I ( I I I I I \l I I J I ; I I I I I I '- I I I u I I I LJ ~ ! ' What 1s the reason for reevaluat1ng the 1981 spec1es select1on? Are there other relevant cr1ter1a than the three ment1oned here that must be cons1dered If so, what are they? Hab1tat Su1tab1l1ty W1ll the ex1st1ng U S F1sh and W1ldl1fe Serv1ce Alaska models be used to der1ve HSI or w1ll the consultant develop h1s own? Impact Assessment Rather than depart1ng from the standard HEP analys1s because of the uncerta1nty of future development, we suggest development of three scenar1os that descr1be vary1ng levels of 1mpact to the area and use them to complete the HEP analys1s We bel1eve that there 1s currently enough 1nformat1on for development of these scenar1os 10-33 f 334 WEST 5th AVENUE· ANCHORAGE, ALASKA 99501 RECEUVE'D DEC 2 1982 A. I. [l.()DfR The Honorable Ronald 0. Skoog, Cormn1ss1oner Alaska Department of F1sh & Game Subpart Bu1ld1ng Juneau, Alaska 99801 Dear Comm1ss1oner Skoog November 26, 1982 Phone (907) 2n-7641 (907) 276-0001 Please reference your agency's letter of February 18, 1982, concern1ng Chakachamna Hydroelectr1c Pro1ect 1982 Work Plan, Env1ronmental Stud1es The Alaska Power Author1ty apprec1ates the deta1led comments your agency has prov1ded, but due to severe budget restra1nts we have not yet been able to 1mplement most of those The Power Author1ty through our consultant, Bechtel/Woodward-Clyde, has collected f1shery data dur1ng th1s past summer and fall Your agency personnel were 1nv1ted to v1s1t the proposed proJect area wh1le Woodward-Clyde was actually collect1ng th1s data dur1ng August 1982 We would l1ke to 1nv1te you and your staff to a meet1ng at 9 30 AM on December 9, 1982, 1n the new Federal Bu1ld1ng, Nat1onal Weather Serv1ce, 5th floor, East Conference Room The purpose of the meet1ng w1ll be to present 1nformat1on collected dur1ng the summer and fall and answer quest1ons on an 1nformal bas1s concern1ng the resource 1n the area I have attachea an agenda for the meet1ng We have requested add1t1onal fund1ng for the FY 84 budget year 1n order to complete the feas1b1l1ty study. Once leg1slat1ve approval has been acqu1redj a new work plan for env1ronmental stud1es w1ll be developed tak1ng 1nto account concerns prev1ously expressed by your agency and others It 1s our 1ntent to coord1nate th1s plan w1th the concerned agenc1es. Thank you for your cont1nued part1c1pat1on 1n our plann1ng act1v1t1es cc Robert Loder 9 Bechtel Wayre L1fton, Woodward=Clyde Kenneth Plumb, FERC S1ncerely, kS?~~ Execut1ve D1rector Carl M Yanagawa, Alaska Department of F1sh & Game Don McKay, Alaska Department of F1sh & Game Ph1 Byrna, Alaska DepartmPnt of F1sh & Game Attachment Agenda 10-34 I I I i ----1 i I ~~J - I I \ J I I I I - \ I l I l I I I ' I I I \ I I I (- i I l -1 \~ I I I February 18, 1982 Mr Er1c P Yould Execut1ve D1rector Alaska Power Author1ty 333 West 4th Avenue, Su1te 31 Anchorage, Alaska 99501 Dear Mr Yould U S D!EPARTMEffi1J' C J;OMMIEIRCE National Ocaenu; Blnld ...... mosphall'lc Admln!mt:rli!ltlan Nat~onat Mar~ne F~sher~es Serv~ae p 0 Box 1668~ Juneau~ Alaska 99802 REGElVED We have rece1ved the Chakachamna Hydroelectr1c ProJect Inter1m Report - November 30, 1981, and the 1982 Work Plan for Env1ronmental Stud1es Assoc1ated w1th th1s proJect We have completed our rev1ew of both documents and offer the follow1ng comments The Intenm Report, accord1ng to your letter of January 8, 1982, 1s be1ng d1str1buted 1n order to prov1de add1t1onal data on wh1ch to base comments regard1ng the 1982 Env1ronmental Stud1es Work Plan Accord1ngly, we have l1m1ted our rev1ew of th1s document only to those sect1ons pertl- nent to the Env1ronmental Stud1es program, sect1ons 6 and 10 Sect1on 6 prov1des a summary of those reconna1ssance-level surveys conducted dur1ng the 1981 season Although l1ttle data are prov1ded, th1s sect1on 1dent1f1es areas that appear to be 1mportant to f1sher1es resources and d1scusses gaps 1n ava1lable knowledge Sect1on 10 (descr1b1ng the 1982 stud1es) and the 1982 Env1ronmental Stud1es Work Plan both target upon these 1mportant areas However, we feel some caut1on should be used 1n bas1ng future stud1es heav1ly on the results of the 1981 work Paragraph 6 3 4 states that these surveys were of "l1m1ted durat1on" and prov1de only a l1m1ted "look" at these r1 ver systems The extent of p1nk salmon spawn1ng and the locat1on of such spawn1ng w1th1n the Chakachatna R1ver are unknown The same 1s true for coho w1th1n th1s system Only l1m1ted survey work occurred on r1vers tr1butary to Ken1buna Lake or w1th1n Ken1buna Lake 1tself The strength of the 1981 salmon runs may not have been representat1ve, as even year runs of p1nk salmon 1n upper Cook Inlet are larger than odd year runs It w1ll be 1mportant for 1982 study efforts to rema1n flex1ble 1n order to fully understand the f1sher1es resources of the proJect area The 1982 Work Plans presented to us do not have th1s flex1b1l1ty or suff1c1ent scope to adequately assess 1mpacts or 1dent1fy necessary m1t1gat1ve measures We have made some spec1f1c comments on both documents, wh1ch follow 10-3 5 2 Inter1m Report 10 1 3 Reservo1r and F1sh Passage Fac1l1t1es The report states that stud1es Wlll be conducted regard1ng f1sh passage 1nto and out of the reservo1r The Env1ronmental Stud1es Work Plan does not 1dent1fy these stud1es What type of research 1s be1ng d1scussed here? 10 3 Env1ronmental Stud1es Th1s paragraph 1mpl1es that current m1n1mum flows were based on f1eld research on f1sher1es These prel1m1nary releases were developed us1ng a percentage of mean flow (the Montana Method) and do not necessar1ly meet the needs of the f1shery resources w1th1n the system 1982 Work Plan -Env1ronmental Stud1es General -We do not bel1eve the proposed stud1es are of suff1c1ent scope to ach1eve the stated ObJeCtlves of prov1d1ng data to accurately prepare env1ronmental exh1b1ts for the FERC appl1cat1on, assess proJect 1mpacts, descr1be ex1st1ng cond1t1ons or develop m1t1gat1on measures At th1s t1me we are most concerned w1th 1dent1f1cat1on of waters w1th1n the proJect area whlch support hab1tat ut1l1zed by f1sh, evaluat1on of altered flow to f1shery hab1tat and the 1mpact of altered temperature reg1mes The 1982 f1sh survey s1tes should 1ncrease our understand1ng of the relat1ve value of prOJect waters as hab1tat We are pleased that 1nstream flow group (IFG) methodolog1es are be1ng proposed to assess changes 1n hab1tat values However, we bel1eve that a proper appl1cat1on of th1s system requ1res cons1derable effort beyond that wh1ch 1s presented 1n the work plan Input from several areas 1s requ1red 1n order to apply the IFG methodology It w1ll be necessary to know the d1str1but1on of f1sh spec1es w1th1n the system, to select target spec1es and l1fe stages, and to correlate th1s 1nformat1on w1th add1t1onal 1nput concern1ng hydro- logy and proJect operat1ons We real1ze that much of th1s descr1pt1on would be too deta1led to be 1ncluded 1n a general work plan Hov'ever, as th1s study element 1s cr1t1cal to 1mpact assessment and m1t1gat1on plann1ng, we bel1eve a separate scope of work should be prepared and c1rculated for comment wh1ch deals w1th the IFG methodology as 1t appl1es to the Chakachamna proJect stud1es The work plan does not adequately address the 1ssue of altered temperatures We suggest that the upcom1ng stud1es allow for th1s 1mportant 1ssue Cont1nuous record1ng themographs may be valuable at s1tes wh1ch may be 1mpacted by thermal changes W1ll a temperature model be prepared? 1 The Work Plan fa1ls to d1scuss how m1t1gat1ve measures w1ll be developed for 1nclus1on 1nto the l1cense appl1cat1on We suggest early coord1nat1on between the contractor and resource agenc1es on th1s 1ssue A m1t1gat1on pol1cy s1m1lar to that be1ng developed for Sus1tna would be valuable Page 4, paragraph 5 The cr1ter1a used 1n select1ng these wetlands for study are not ment1oned Are these areas assumed to be representat1ve of the wetlands w1th1n the area of 1mpact or of a spec1al value as hab1tat? 10-36 I I I I I I ' I I I I I I I I I I_ I I I I I I I I ~-I I I 3 Page 7, paragraph 2 The 1nstream flow 1nvest1gat1ons w1ll prov1de necessary data on the 1mpacts of flow regulat1on Based on prel1m1nary 1nformat1on presented by Woodward-Clyde 1t appears that sloughs or s1de channels 1n the upper McArthur and 1n the Chakachatna R1ver below Stra1ght Creek are 1mportant spawn1ng areas Many of these channels may be 1mpacted by altered flows and should be 1nvest1gated us1ng 1n-stream flow methodology The Work Plan 1s not clear on whether these s1tes w1ll rece1ve spec1al attent1on, but states that new s1tes w1ll be stud1ed us1ng IFG-2 methodolog1es We feel that some new s1tes (such as s1de channels ut1l1zed by spawners) should rece1ve the IFG-4 methodology to more closely assess proJect 1mpact Page 7, Aquat1c B1ology The work plan does not descr1be what work 1s planned for further l1mnolog1cal 1nvest1gat1on of Lake Chakachatna or Ken1buna Water qual1ty parameters, depth prof1les and plankton tows are some th1ngs that should be cons1dered F1nally, we must express our concern w1th regard to the proJect schedule It 1s unl1kely that any study effort, regardless of 1ts thoroughness, could properly 1dent1fy the f1shery and related 1mpacts w1th1n a 10 month per1od (February to November) The fact that l1ttle 1nformat1on currently ex1sts for these systems adds to th1s concern, as much work w1ll be needed to gather bas1c reconna1ssance-level data We suggest the t1m1ng of the FERC l1cense appl1cat1on and the scope of envlron- mental stud1es for th1s prOJect be recons1dered Wlth an a1m at 1nsur1ng a thorough understand1ng of the resources and a profess1onal assessment of prOJect related 1mpacts and m1t1gat1on opportun1t1es We apprec1ate th1s opportun1ty to comment at th1s t1me S1ncerely, -~~ 77 ~7--~-<!--~obyrt W McVey ~ector, Alaska Reg1on 10-37 / Phone (907) 2n 7641 I I I _j 334 WEST 5th AVENUE ANCHORAGE, AlASKA 99501 RECEIVED (907) 276-0001 ) DEC 2 1982 R. T LODER Mr Robert W McVey D1rector, Alaska Reg1on Nat1onal Mar1ne F1sher1es Serv1ce P 0. Box 1668 Juneau, Alaska 99802 Dear Mr McVey November 26, 1982 Please reference your agency's letter of February 18, 1982, concern1ng Chakachamna Hydroelectr1c ProJect 1982 Work Plan, Env1ronmental Stud1es. The Alaska Power Author1ty apprec1ates the deta1led commPr.ts your agency has prov1ded, but due to severe budget restra1nts we have not yet been able to 1mplement most of those The Power Author1ty through our consultant, Bechtel/Woodward-Clyde, has collected f1shery data dur1ng th1s past summer and fall Your agency personnel v1s1ted the proposed proJect area wh1le Woodward-Clyde was actually collect1ng th1s data dur1ng August 1982. We would l1ke to 1nv1te you and your staff to a meet1ng at 9 30 A M on December 9, 1982, 1n the new Federal Bu1ld1ng, Nat1onal Weather Serv1ce, 5th floor, East Conference Room The purpose of the meet1ng w1ll be to present 1nformat1on collected dur1ng the summer and fall and answer quest1ons on an 1nformal bas1s concern1ng the resource 1n the area. I have attached an agenda for the meet1ng We have requested add1t1onal fund1ng for the FY 84 budget year 1n order to complete the feas1b1l1ty study Once leg1slat1ve approval has been acqu1red, a new work plan for env1ronmental stud1es w1ll be developed tak1ng 1nto account concerns prev1ously expressed by your agency and others. It 1s our 1ntent to coord1nate th1s plan w1th the concerned agenc1es Thank you for your cont1nued part1c1pat1on 1n our plann1ng act1v1t1es cc ~obert Loder, Bechtel Wayne L1fton, Woodward=Clyde KPnneth Plumb, FERC S1ncerely, b P. Yo~"\JA- Execut1ve D1rector Ronald Morr1s, Nat1onal Mar1ne F1sher1es S~rv1ce Brad Sm1th, Nat1onal Mar1ne F1sher1es Serv1ce Attachment Agenda 10-3 8 lj I t _I rl I I I I I rJ I I il I ~\ I I I I ~1 I I I I I \ I I I I I I I I I ~-! I I ( I I 10 3 3 Meet1ng -December 9, 1982 Representat1ves of the agenc1es llsted below were 1nv1ted to attend a meet1ng 1n Anchorage, Alaska on December 9, 1982 o U s. F1sh and W1ldl1fe Serv1ce o Alaska Department of F1sh and Game o Natlonal Mar1ne F1sher1es Servlce o Nat1onal Park Serv1ce o Alaska Department of Natural Resources o Northern Alaska Env1ronmental Center At th1s meet1ng, representat1ves of Alaska Power Author1ty, Bechtel C1v1l & M1nerals, Inc., and Woodward- Clyde Consultants presented a summary of results of the 1982 eng1neer1ng and env1ronmental stud1es performed on the proJect A copy of the meet1ng notes 1s reproduced on the follow1ng pages 10-39 DATE LOCATION SUBJECT PARTICIPANTS CHAKACHAMNA HYDROELECTRIC PROJECT MEETING NOTES December 9, 1982 Anchorage, Alaska Chakachamna ProJect Rev1ew Meet1ng Alaska Power Author1ty Eric Marcheg1ani Bechtel Bob Loder Dave Cornman Woodward-Clyde Wayne Lifton Larry Rundqu1st M1ke Joyce Nat1onal Park Serv1ce Larry Wr1ght Alaska Department of Natural Resources Karen Oakley Alaska Department of F1sh and Game Ken Tarbox Bruce K1ng Ph1l Brna Kev1n Delaney J1m Faro Gary L1ep1tz U.S F1sh and W1ldl1fe Serv1ce Lenny Carin Gary Stackhouse Nat1onal Mar1ne F1sher1es Serv1ce Brad Sm1th NAEC m'C Meyers Representat1Ves from Alaska Power Author1ty, Bechtel C1v1l and M1nerals, and Woodward-Clyde Consultants (WCC) presented a summary of results of the 1982 eng1 neer1 ng and env1 ronmenta 1 stud1es performed on the Chakachamna Hydroelectr1c ProJect to local, state, and federal agency personnel The purpose of the meet1ng was to prov1de background 1nformat1on to new agency personnel, to 1nform all present of new proJect data, and to rece1ve agency 1nputs regard1ng study results and future proJect plans. 10-40 \ I I I I i I --, I I I I l I I I I I I I I I '~ r I I I i I I I ,_ 'I I I I I I I ~~I r , I I l J Er1c Marcheg1an19 Alaska Power Author1ty 9 1n1t1ated the meet1ng by 1ntroduc1ng those present. A 61-page handout was d1str1buted conta1n1ng deta1led draw1ngs of conceptual f1sh passage fac1l1t1es of 1982 f1sher1es data and other relevant 1nformat1ono Er1c then rev1ewed pr1nc1pal proJect events wh1ch have occurred s1nce the last proJect rev1ew meet1ng, December 11i 1981. In add1t1on~ Er1c rev1ewed the Power Author1ty requests for funds and the funds appropr1ated, by the Leg1slaturei for Chakachamna ProJect s1nce 1981. The FY 83 budget made 1t poss1ble to 1nvest1gate f1sh passage 1nto and out of the lake, enumerat1on of the f1shery resources, and an evaluat1on of a reduct1on 1n the cost est1mate due to ut1l1z1ng a tunnel bor1ng mach1ne. The Power Author1ty has requested $2 9 m1l11on for FY 1984, to carry the proJect through out Federal Energy Regulatory Comm1ss1on {FERC} l1cens1ng Bob Loder, Bechtel, br1efly rev1ewed the eng1neer1ng stud1es performed to evaluate var1ous dam and tunnel alternat1ves for develop1ng the Chakachamna Lake hydro resource. These stud1es were reported 1n the 1981 Inter1m Report. These eng1neer1ng and cost stud1es showed that a Chakachamna Lake tap and tunnel dwers1on to the adJ01mng McArthur R1ver was the most attract1ve alternat1ve for power development A prel1m1nary cap1tal cost est1mate of $1 2 b1ll1on was arr1ved at assum1ng the use of tunnel bor1ng mach1nes Loder then prov1ded a deta1led rev1ew of the f1sh passage fac1l1ty concepts developed 1n 1982 Fac1l1ty structures and operat1on were descr1bed on large mult1-colored wall draw1ngs Seasonal passage for downstream and upstream m1grant f1sh 1s prov1ded at all proJected lake operat1ng levels F1sh passage fac1l1t1es cons1st of a one m1le long d1v1ded tunnel from the lake outlet to a po1nt downstream on the Chakachamna R1ver, a mult1-level sp1ral1ng f1sh ladder for upstream m1grants, and two alternat1ve lake out- let fac1l1t1es for downstream m1grants Wayne L 1 fton (WCC} presented a br1ef overv1ew of env1 ronmenta 1 stud1es performed to date on the proJeCt. Larry Rundqu1 st (WCC) then summar1 zed the results of the 1982 hydrolog1c stud1PS conducted 1n August and October Gage locat1ons were 1llustrated. The data base for record1ng gages on the Chakachamna and McArthur R1 vers was prov1 ded 1 n overhead presentat1 on, along w1th a summary of the staff gage data base A general descr1pt1on of flow d1stnbut1on and sed1ment character1st1cs was gwen based on f1eld observat1ons and prel1m1nary data. L1fton then presented the prel1m1nary results of the 1982 f1sher1es program w1th a sl1de presentat1on 1llustrat1ng the 24 sampl1ng stat1ons. Study emphas1s was placed on the Chakachamna R1ver F1sh hab1tat, hab1tat ut1l1- zat1on, and spawn1ng were 1nvest1gatedo Fyke nets and other gear were used 1n r1vers and streams and g1ll nets, se1nes, and shock1ng werP used on the 1 ake The results were summarlZed 1 n f1 gures (overhead presentat1 on of graphs} represent1ng each sampl1ng stat1on Prel1m1nary presentat1on of graphs) represent1ng each sampl 1 ng stat1 on Prel 1m1nary escapemPnt est1 ~ mates were prov1ded 1n thP handout. It appears that only Sockeye and Dolly Varden are found 1n streams above Lake Chakachamna 10-41 The maJor quest1ons and concerns vo1ced at the meet1ng are l1sted below General· * Er1c Marcheg1an1 -The total cost est1mate 1s based on the Power Author1tyas econom1c parameters. Do not compare these costs w1th those on the Sus1tna ProJect, unless they ut1l1ze the same parameters 1n an econom1c compar1son. F1sh Passage Fac1l1t1es * Would someone be on s1te to control the gates? * * The system can operated manually or by automat1c sensors Has th1s system been used elsewhere 1n an automat1c mode? An ex1st1ng reservo1r 1n Oregon accorrmodates s1m1lar change 1n water level A ladder 1s convent1onal, however, the water supply chambers and open1ngs to the reservo1r are unconvent1onal Has a gated system been used before? I II I I I (II I I I 1 Not sure, need to f1nd out. Th1s 1s not exot1c change from what ,_, has been used 1n the past The most d1fferent feature 1s the one-m1le~long tunnel * Is there an aux1l1ary water system to ach1eve 1 9 000 cfs? * * * That 1s part of the downstream m1grat1on system, and w1ll be d1scussed later W1ll a dark tunnel make avo1dance probable? The tunnel could be l1ghted 1f nece~sary Could th1s create ma1ntenance problems? There w1ll be veh1cular access Someone would check fac1l1t1es on a regular bas1s. The powerhouse operator would check water levels and gates W1ll the water temperature be regulated 1n the lower outlet' No, not as planned It JUSt takes water from the channel Water taken from the lower depths would be colder Thermocl1ne may cause f1sh to pool up 10-42 I I, J I I____, I I I I I I I I I I -. : I I I I I I ___) I I I I i I I_ I I I I I ' I ~ I I LJ - I I I I I I r -~ 1 I \ I * Would th1s be a year~round operat1on? Yes * How w1ll 1ce and debr1s be handled 1n the system (1.e , at the grate)? * * * * * * * We would probably prov1de means of el1m1nat1ng 1ce and debr1~ at the 1ntake After November 1, no f1sh w1ll be go1ng upstream Ice 1s an 1ssue that has to be dealt w1th 1n the des1gn of the fac1l1t1es What 1s the depth of the power tunnel 1ntake? Approx1mately 150 feet below normal lake level and below lake level 1n the spr1ng W1 11 downstream m1 grants f1 nd the power outlet or 1 ake outlet {attract1on)? Intake must be des1gned so they do not f1ned the power 1ntake What 1s the poss1b1l1ty of vary1ng temperature 1n the McArthur? Have not addressed th1s problem yet. Expla1n the dyke. Where does 1t term1nate? Protect1ve dev1ce for des1gn of f1sh channel. Channel has to be excavated to allow water entry at dayl1ght level What 1s cost est1mate of tunnel' Do not know yet, but there 1s an advantage of a totally grav1ty system {pumps are another opt1on) The water level var1at1on was ra1sed to accomnodate the grav1ty system {1,195 feet to 1,095 feet) W1ll slough hab1tat be mod1f1ed downstream? Th1s 1s another aspect wh1c~ w1ll be addressed later F1sher1es Stud1es * Expla1n the graphs. L1ve f1sh counts were made on weekly bas1s Counts were plotted versus consecut1ve days Area under curve f1sh-days, these are d1v1ded by the amount of t1me the f1sh were 1n stream and result 1n est1mated total number of l1ve f1sh per stream 10-43 * * * * * * Essent1ally, the same techn1que was used on Sus1tna ih1s 1nformat1on was supplemented w1th electroshock1ng, nett1ng 9 and ground counts Data gaps d1d occur dur1ng the September storm How many people counted f1sh' Two. How d1d you cover the area? Hel1copter was equ1pped w1th spec1al bubble w1ndows Overfl1ghts were made as slow and as near to the qround as poss1ble Were there f1sh at streams you could not mon1tor' We counted every stream 1 n wh1 ch spawm ng f1 sh were found and some where there were no f1sh Were you aware of when runs began? We took the hel1copter out once a week for the ent1re schedule, essent1ally s1nce m1d-July It 1s hard to understand how two people d1d all that Actually, f1ve or s1x people were 1n the f1eld cover1ng spawn1ng r1ght now W1ll count data be presented? I am JUSt Each count w1ll be recorded The hydroacoust1c survey was conducted dur1ng the fall to count JUVen11e d1str1but1on 1n the lake (overhead presentat1on) We were eventually weathered out. What 1 s the d1 str1 but1 on at 100 feet? What do the m ne and twelve mean' Number of f1 sh per m3 x 10 3 F1 sh were gerera lly found deeper than prev1ously expected, to 100 feet The numbers are ten foot depths 1ntervals F1sh were shore-or1ented 01d you f1nd any lake trout? Yes, qu1te a few 01d you 1dent1fy any areas where lake trout were concentrated? We 1dent1f1ed large concentrat1ons of lake trout 1n 1981 10-4 4 I I r _) II I I I I I I I I I I I ( I - \ I I I I '~ I I I I I ' I I I I I 1 I I \ L_ * How many Dolly Varden were there' * * * They are res1 dents and pr1mar1 ly caught by gear wh1 ch g1Ves relat1ve abundance, so can only est1mate. ~re Dolly Varden the most abundant' Maybe, hard to say~ lots of sl1my sculp1n, pygmy wh1tef1sh, etc. Also, lots of JUVen11e sockeye 1n lake. Are escape est1mates m1mmum numbers and d1d you only count clearwater streams' Clearwater counts were great We feel very conf1dent 1n those areas When streams clouded up as 1n September~ counts were much less rel1able. Many cloudy areas-s1de channels were countable and counts were corrected by ground truth1ng Any spawn1ng 1n ma1nstream 1nd1cated or seen? Ma1nstream areas do not seem to be used. The water was too turb1d, substrates were bad for spawn1ng. Only f1sh we found 1n ma1nstream were not r1pe or were spawned out (m1grants) When was fyke nett1ng started' August 6 What was your recovery on tagged adult f1sh? Not count1ng Dolly Varden, under 150 Petersen tagged salmon Of a 11 spec1 es? No~ pr1mar1ly sockeye, coho, and chums, w1th some p1nks General D1scuss1ons Er1c Marcheg1an1, Power Author1ty, expla1ned the process for future proJect fund1ng A d1scuss1on ensued on the need to develop a deta1led plan of study for full feas1b1l1ty early 1n 1983 pr1or to cont1nuance of planned f1eld stud1es A two-st~p approach to agency rev1ew was suggested 1) Ident1fy program elements and set pr1or1t1es, 2) Prov1de deta1l on agreed upon l1st of programs and pr1or1t1es Er1c Myers (NAEC) expressed concern regard1ng the FERC l1cens1ng process on the Sus1tna ProJect and an apparent lack of comm1tment to adequately study Chakachamna as an alternat1ve to Sus1tna Er1c Marcheg1an1 assured every- one that the Power Author1ty 1s comm1tted to evaluat1ng Chakachamna as an element of an alternatwe to Sus1tna as requ1red for FERC l1cens1ng In add1t1on, the Power Author1ty 1s pursu1ng a deta1led feas1b1l1ty study of 10-45 Chakachamna as an 1ndependent proJect as 1nd1cated by 1ts request for $2.9 m1ll1on for the ProJect 1n FY 84 Er1c Marcheg1an1, Power Author1ty, concluded the meet1ng, 1nd1cat1ng that the next report w1ll be out by the end of February. There w1ll be a June Addendum to cover winter and spnng work Please rev1ew the f1sh and bypass system and prov1de your ideas to us. We w1ll meet to d1scuss plans for spr1ng and w1nter. 10-4 6 I ') [I I I I I I I J I I I I I I ( I 1 : '_) I I I \ I ) \ ~ I \ I I i I r I I I I I I I I ) I = 1 I I I I I I I I I : v I I I I I I D1str1but1on of December 9, 1982 Meet 1 ng Summary The Honorable Esther Wunn1cke Cormn1ss1oner Department of Natural Resources Pouch M Juneau, Alaska 99811 cc Mr Robert Loder, Bechteli San Franc1sco Mr Wayne L1fton, Woodward-Clyde, Anchorage Ms Kay Brown, D1v of M1nerals & Energy Mgt , DNR, Anchorage Ms Karen Oakley, D1v of M1nerals & Energy Mgt , DNR, Anchorage M~ Roland Shanks, D1rector, D1v of Research and Development Mr Robert W McVey, D1rector Alaska Reg1on Nat1onal Mar1ne F1sher1es Serv1ce Post Off1ce Box 1668 Juneau, Alaska 99802 cc Mr Robert Loder, Bechtel, San Franc1sco Mr Wayne L1fton, Woodward-Clyde, Anchorage Mr Brad Sm1th, Nat'l Mar1ne F1sher1es Serv1ce, Anchorage Mr Ronald Morr1s, Nat'l Mar1ne F1sher1es Serv1ce, Anchorage Mr Ke1th Schre1ner Reg1onal D1rector 1011 East Tudor Road Anchorage, Alaska 99503 cc Mr Robert Loder, Bechtel, San Franc1sco Mr Wayne L1fton, Woodward~Clyde, Anchorage Mr Lenny Cor1n, U S F1sh & W1ldl1fe Serv1ce, Anchorage Mr Gary Stackhouse, U S F1sh & W1ldl1fe Serv1ce, Anchorage Comm1SS1oner Alaska Department of F1sh & Game Subpart Bu1ld1ng Juneau, Alaska 99801 cc Mr Robert Loder, Bechtel, San Franc1sco Mr Wayne L1fton, Woodward-Clyde, Anchorage Mr Carl Yanagawa r1r Don McKay D1rector Nat1onal Park Serv1ce 540 West F1fth Avenue, Room 201 Anchorage, Alaska 99501 cc Mr Robert Loder, Bechtel, San Franc1sco Mr Wayne L1fton, Woodward~Clyde, Anchorage Mr Larry Wr1ght, Nat1onal Park Serv1ce, Anchorage 10-47 10 3.3 1 Response The Nat1onal Mar1ne F1sher1es Serv1ce and U S F1sh and W1ldl1fe Serv1ce repl1ed to the Power Author1ty's 1nv1tat1on to comment on the proposed conceptual des1gns of the f1sh passage fac1l1t1es for the Chakachamna Lake outlet as descr1bed at the December 9, 1982 meet1ng Cop1es of the NMFS February 1, 1983 letter and U S F1sh and W1ldl1fe Serv1ce March 9, 1983 letter are reproduced on the follow1ng pages. The1r suggest1ons have been taken under adv1sement but t1me does not perm1t act1on by the Power Author1ty at th1s JUncture Present plans prov1de for an addendum to th1s March 1983 Inter1m Feas1b1l1ty Assessment Report to be 1ssued as rap1dly as poss1ble after the spr1ng stud1es have been completed 1n June 1983 The Power Author1ty's response to NMFS and U S F1sh and W1ldl1fe Serv1ce suggest1ons Wlll be addressed 1n that addendum 10-48 ( l I \ I I I I , ) 1 I I I (l I ~I I -~ r 1 ' ~l I I {II I I ,_ -I 1 I ( , I tl I I - -- r I I I /" I I I i - . . - February 1, 1983 Mr. Er1c Marcheg1an1 Alaska Power Author1ty 334 W. 5th Avenue Anchorage, Alaska 99501 Dear Mr Marcheg1an1 UNITED STATES ltk,...,AI!UMIENT OF COMMERCE Nat1onal Ocearuc ar11d Atmospheric Adman1stratsan Nat?;onaZ Mazt1..ne F1;ahenea Servwe P.O Box 1668 Juneau, AZaska 99802 0 FILES ..,roject 0 General 0 Vol Rf,~FilidiQ ~~ate Entere""ildr:--------- ' ... 0 7 1983 ALASKA POWER AUTHO~ The Nat1onal Mar1ne F1sher1es Serv1ce has rev1ewed the Summary of F1sh Passage Fac1l1ty Des1gn Concepts and Prel1m1nary Results of FY 1982-83 F1sh Stud1es -Chakachamna Hydroelectr1c ProJect, Bechtel/Woodward Clyde, December 1982 Our F1sh Fac1l1t1es D1V1s1on has developed comments spec1f1c to the conceptual passage des1gns, and we are forward1ng these for your cons1derat1on pr1or to complet1on of the February report We w1ll be able to prov1de a more complete analys1s of f1shways des1gn when operat1onal concepts are f1nal1zed The proposed f1sh passage structures appear feas1ble, but we bel1eve relat1vely h1gh mortal1ty w1ll occur w1th respect to out-m1grants 1 The turn pools at all ladder turns are too short The 1nter1or ladder wall at all turns should extend at least 8 feet upstream and downstream from the adJacent we1rs. The exter1or wall would of course extend further than 8 feet 2 All adult f1sh ladders and channels must be l1ghted to encourage f1sh movement Natural l1ght or art1f1c1al l1ght can be used Access for art1f1c1al l1ght1ng ma1ntenance 1s requ1red 3 The upstream passage fac1l1ty shows a ladder w1th 60 pools For th1s or1f1ce-overflow type of ladder to funct1on properly the water surface 1n the pools should be controlled to prov1de 1 0 ft of head on the we1rs, plus or m1nus 0 1 foot The document does not expla1n how the water level 1n the ladder w1ll be controlled dur1ng per1ods when the forebay elevat1on 1s above or below an even-foot elevat1on It 1s assumed flow would be controlled by throttl1ng the 1nlet con- trol gate to the appropr1ate water supply chamber Proper operat1on of the ladder w1ll requ1re faultless operat1on of all 60 gates to the 1nd1v1dual ladder pools and all 1nlet gates to the water supply chambers Th1s w1ll requ1re good access for frequent gate 1nspec- t1on and O&M No method of access lS 1nd1cated 4 The ladder ex1ts must be suff1c1ently removed from the downstream m1grant fac1l1ty to prevent adult f1sh from fall1ng back downstream 10-49 / 5 Both schemes for JUVenlle passage appear to have potent1al for h1gh f1sh losses. Scheme A m1ght be mod1f1ed to avo1d the turbulent plunge pool wh1ch would ex1st, part1cularly when e1ther of the top two drum-type gates are operated The drop of up to 80 feet ± 1nto the bas1n shown would be very hazardous for f1sh, s1nce they would be subJected to extreme turbulence w1th assoc1ated pressure fluctua- tlons and shear forces pr1or to ex1t1ng through the tunnel. H1gh lnJury and mortal1ty rates can be expected Cont1nuous smooth sp1llway crests downstream of each gate to a standard sp1llway st1ll1ng bas1n, and a smooth gradual trans1t1on to the tunnel would be an 1mprovement. Scheme B has more potent1al problems than Scheme A. These are (1) More mechan1cal equ1pment 1s 1nvolved, therefore more chance for malfunct1on (2) The ent1re flow 1s not near the surface where 1t would a1d f1sh outm1grat1on (3) F1sh may not read1ly sound to the depth requ1red to ex1t through the tunnel, after they pass over the flow control plate (4) F1sh pass1ng through the two 7 ft x 4 75 ft tunnel d1scharge control gates can be expected to suffer h1gh mortal1t1es, based on exper1ence at other proJects of even lower max1mum heads (5) Some f1sh can be expected to ex1t the forebay through the two low level bypasses, part1cularly 1f lower forebay elevat1ons ex1st dur1ng outm1grat1on, and flow cond1t1ons 1n the bypass condu1ts could be damag1ng to f1sh 6 The proposed breakwater 1n the lake could result 1n downstream m1grants not f1nd1ng the lake outlet so read1ly The locat1on and length of the breakwater and 1ts relat1onsh1p to shorel1ne topography should be corsldered very carefully to avold anadromous f1sh passage problems •. The approach channel to the lake outlet should be des1gned w1th cons1derat1on to ma1nta1n1ng adequate veloc1t1es to move f1sh to the outlet structure 7 The proposed power outlet from the lake to the powerhouse w1ll apparently be located cons1derable d1stance from the f1sh passage fac1l1t1es No 1nformat1on 1s g1ven as to the magn1tude of the power d1scharges Power d1scharges can be expected to detract from the l1m1ted outm1grant attract1on prov1ded by the f1sh passage fac1l1t1es, reduc1ng the1r effect1veness 1n ma1nta1n1ng f1sh runs Should you have any quest1ons regard1ng these comments, please contact our Anchorage F1eld Off1ce at 271-5006 i S1nceQ~ 91 ;;?~ Robe,i W McVey 1 /o~ctor, Alaska Reg1on I / 10-5 0 I I r \ I I I ' C: ( I /' I I I I r ~ ' ) ( I United States Department of the In tenor (I IN REPLY REFER TO r f' WAES I I FISH AND WILDLIFE SERVICE 101 { E TUDOR RD ANCHORAGE, ALASKA 99503 (907) 276-3800 I ' I I u f \' I I I~ ' I i ~~~ ;j I f I [,1 Er1c P Yould, Execut1ve D1rector Alaska Power Author1ty 334 West 5th Avenue Anchorage. -xi ask a 99501 Dear Mr Yould 0 9 MAR IYbj The F1sh and W1ldl1fe Serv1ce has rev1ewed the report prepared for you on the Chakachamna Hydroelectr1c ProJect by Bechtel/Woodward-Clyde 1n December 1982 ent1tled, A Summary of F1sh Passage Fac1l1ty Des1gn Concepts and Prel1m1nary Results of FY 1982-83 Fish Studies Our comments below are specific to the conceptual fish passage structures 1llustrated 1n the report and do not address the f1sh1ng stud1es. Prev1ous letters, dated 5 March~ and 26 March, 1982, prov1de comments wh1ch are st1ll pert1nent to the on-go1ng f1sh and w1ldl1fe stud1es The follow1n~ comments are presented 1n the order of the sketches conta1ned 1n the Bechtel/Woodward-Clyde report Draw1ng No. SK-C-001. 1. The proposed reduct1on 1n d1scharge at the lake outlet m~ accelerate the lakeward movement of Barr1er Glac1er toward the proposed approach channel and passage fac1l1ty structure. Accord1ng to U.S. Geolog1cal Survey measurements made dur1ng 1961 through 1966, th1s glac1er advanced several feet per year at measur1ng stat1ons located near the r1ver bank at the lake outlet 2. Ant1c1pated flows 1n the v1c1n1ty of the rock-f1ll f1sh barr1er should be determ1ned Draw1ngs No. SK-C-002. SK-C-003. 1. F1shway pools numbered 1105, 1125, and 1145 should be at least ten feet 1ongp cons1stent w1th the des1gn of the other f1shway pools 2 Prov1s1on for an access walkway along the top of the f1shway pools and natural or art1f1c1al l1ght1ng should be prov1ded. 10-51 3 4. 5. The proposed f1shway 1s a we1r type (s1x foot by ten foot pools) w1th spl1t Ice Harbor type baffles Each f1shway pool would have the standard bottom or1f1ce plus an add1t1onal gated open1ng 1n the outs1de wall of each pool to compensate for the ant1c1pated 60 foot fluctuat1on 1n lake level. We recommend the follow1ng des1gn parameters for the f1shway baffles We1r crest he1ght = We1r overflow w1dth = Or1f1ce s1ze = F1shway flow = 6 feet 3 feet 18 1nches x 18 1nches 27 cub1c feet per second (w1th 12 1nch head on baffle) Gate operat1ng mechan1sms for the 60 gated open1ngs 1n the f1shways are not shown We understand gate operat1on would be automat1c, us1ng sensors wh1ch open and close des1gnated gates, and would compensate for changes 1n lake level Due to the large number of gates, we ant1c1pate operat1on and ma1ntenance problems Reduc1ng the extent of lake fluctuat1ons dur1ng the upstream m1grat1on per1od would reduce the number of gated open1ngs requ1red. The f1shway pool s1ze 1s dependent upon the des1gn populat1on of f1sh to be passed The des1gn populat1on w1ll need to be establ1shed and f1shway pool s1ze should then be adJusted accord1ngly Draw1ng No. SK~C-004 1. The downstream m1grant fac1l1ty should draw flow from the surface of the lake as 1pd1cated on th1s draw1ng However, the passage of 1ce through th1s system w111 be a problem dur1ng the w1nter and spr1ng 2. The drop from the upper gate 1nto the plunge pool can be decreased by ut1l1z1ng an or1f1ce or gate at the entrance to the d1scharge tunnel. Draw1ng No. SK-C-005 1. Scheme B may not prov1de suff1c1ent flow from the surface of the lake to be effect1ve for downstream m1grants The establ1shment of adequate lake releases 1s essent1al to assure that the system max1m1zes outm1grat1on to the estuary Draw1ng No SK-C-006 1. It appears that the adult f1sh 11 fa11 backs .. from the lake w1ll be trapped by the hor1zontal grat1ng proposed at elevat1on 1072 1n the outlet structure Th1s potent1al problem could be avo1ded through use of an angled vert1cal screen or rack 1n l1eu of the hor1zontal grat1ng. Th1s angled rack would also serve to gu1de upstream m1grants to the f1shway 10-52 I I 1\ \ - ~ ( I l ) ~) ( 1\ II I; I A -' ~ i I I ~~ I \ : I v I I I I ' ....... I I If 1 \ J I I ( I - :J I I We hope that these comments are helpful as Bechtel/Woodward-Clyde cont1 nues to ref1 ne the 1111 t1 al passage fac1l1 ty concepts If you have any quest1ons regard1ng our comments, please contact Leonard P Cor1n (907-271-4575) at our Western Alaska Ecolog1cal Serv1ces f1eld off1ce S1 ncerely, cc FWS-WAES ADF&G, NMFS, EPA, Anchorage 10-53 10 4 Nat1onal Park Serv1ce 10 4 1 Lake Clark Nat1onal Park The copy of the January 12, 1982 Power Author1ty letter to Mr Paul Haertel, Super1ntendent of Lake Clark Nat1onal Park 1s reproduced on the follow1ng three pages to 1llustrate the nature of coord1nat1on effected w1th the Nat1onal Park Serv1ce. 10-54 I I I - I I I I -I \ I ~ G \ r- ' y ) I ~ I \J I I l 'I I "'\ ~ I I I ~ I I {_.,I -~ ;, I l_l I ~\ I I ! ALASKA POWER. AUTHORITY 334 WEST 5th AVENUE ANCHORAGE, ALASKA 99501 Mr. Paul Haertel SUperilltendent of Lake Clark NatJ.onal Park Serv1.ce U. S Federal Bw.ldJ.ng Anchorage, Alaska 99501 Dear Mr. Haertel January 12, Phone (907) 277 7641 (907) 276 0001 We are presently undertakl.ng a feasl.b1.l1.ty study of the proposed Chakachanma Hydroelectr1.c ProJect. The study ccmrenced ill August 1981 and 1.s scheduled for carnplet1.on ill early 1983 ( The proJect area l.S located approxJ.Inately 60 Inl.les west of Anchorage. The water storage reservo1.r for the proposed hvdro:pcMer proJect 'WOuld be exJ..stl.Ilg Chakachamna Lake, a 23 square-rrJ..le lake forrred ill a steep valley behl.nd a glac1.al norame CUrrent stufues have 1.dent1.f1.ed several alternat1.ve arrangements for the proJect The al ternatJ. ve Wl. th the greatest power potentJ.al illvol ves a lake tap leadl.Ilg through an 11 Inl.le transrrountal.n fu vers1.on tunnel to a power plant on the McArthur RJ. ver Such a d1. vers1.on of flOVJ rray have s1.gn1.f1.cant env1.ronrnental 11I1pacts ill the McArthur Rl. ver and ill the Chakachatna RJ. ver, the outlet stream fran Chakachamna Lake These two r1.vers are known to have runs of anadrarous f1.sh The planned proJect constructl.on for any of the alternatJ.ve layouts presently under cons1.deratJ.on does not illvolve any canstructl.on act1.v1.tJ.es wl.thill the boundar1.es of Lake Clark Nat1.onal Park HCMeVer, as stated above, the proJect operatJ.on rray affect the f1.sh and W1.ldl1.fe ill the Chakachatna Rl. ver basill illcludl.Ilg part of the NatJ.onal Park by fu vers1.on of water fran the Chakachatna RJ.ver and by seasonal lowerillg of the level of Chakachamna Lake The work beillg perfonred ill the feasl.b1.l1. ty study illcludes an assessment of the env1.rornrental mpact of the proJect canstruct1.on and operatJ.on. To evaluate the illfluence of the proJect on the f1.sh and W1.ldl1.fe p::>pUl.atl.ons of the area 1. t l.S necessary to illclude ill th1.s evaluatJ.on those resources w1.thl.n the NatJ.onal Park, spec1.f1.cally Keru.buna Lake Sillce a portl.on of the anadrarrous f1.sh run passillg through Chakachamna Lake enters Kenl.buna Lake. At thl.s t.ure, the 1981 env1.ronrnenta.l stufues f1.eld program (aer1.al and ground reconna1.ssance of the general study area) has been completed The f1.rst overv1.ew was conducted ill August w1.th the cbJectl.ves beillg to document the presence of sockeye sa.lm:m ill the rra.Jor proJect waters and to survey the Sl. te ill preparatl.on for the fall reconna1.ssance. The second illVestl.gatJ.on was carr1.ed out m Itll.d-Septernber and l.llVolved two 10-55 ~l Mr Paul Haertel January 12, 1982 Page 2 ,b " weeks of f~eld data collect1.on The obJectl.ves of the effort were to obtam suff~c~ent ~onrat1.on and understandJ..ng of the proJect s1.te and 1.ts resources to allow for the des1.gn of rrore de~led 1982 stud1.es, and to assess, m a prell.Imncu:y nature, the overall feasl.b1.l1. ty of the conceptual des1.gns of the proJect altematl.ves. In th1.s 1981 program, no actJ..v1.t1.es were performed w~thl.n the Nat1.onal Park Smce part of the 1982 f1.eld program w1.ll occur w1.thm Lake Clark Nat1.onal Park, we are reques~g that a spec1.al use pemt be author1.zed for the env1.ronmental mvest1.gat1.ons Spec1.f1.cally, we are requestmg that the followmg nonconsurrptl.ve actJ..v1.t1.es be author1.zed 1.n the Natl.onal Park 0 fly over and land near the Ig1.tna, Neacola, Another, and Clull1.gan Rl. vers usmg a hell. copter, 0 use a rrotor1.zed raft on Keru..buna I.ake, 0 use standard surveymg techn1.ques and depth soundJ..ng equ1.prrent, and 0 conduct vegetatl.on surveys. In adfu non, we request that the followmg consurrptl. ve, yet nondestructJ..ve, a~v1.tl.es be author1.zed 1.n the Nat1.onal Park 0 the collect.l.on of stream and lake substrates to assess stab1.l1. ty, 0 the use of fyke nets, electro shoe~ egu1.prent, and semes (adults captured by these techn1.ques Wl.ll be released) ; 0 the l~ted use of g1.ll nets along the steep banks of the lake shore If used, the g1.ll nets Wl.ll be set for short per1.ods of tJ..Ire to prevent excess1. ve losses. There Wl.ll be no carrpmg or smlar actJ..v1.t1.es assoc1.ated w1.th these above act1.v1.t1.es. A schedule for these act1.v1.t1.es 1.s attached The ~rk descrl.bed above would be performed for the Author1. ty by Bechtel C1. v1.l and Ml..nerals, Inc and theu env1.ronrrental subcontractor Wc:xXiward-clyde Consultants Subsequent to these stuches, we do not antl.c1.pate any further mvest1.gat1.ons WJ. thm the Lake Clark Nat1.onal Park If you have any quest1.ons or 1.f you regu1.re a~tl.onal mformat1.on on any phase of ~s program, please contact rre. Smcerely, Attachment. Schedule t:ffti!f!::- ~ 'l CC ~ To Loder, Bechtel~ 10-56 I I I I-I i ~ I \ I~, I '-J I 1--f. ,I 'l J -, I J --; I L' I ( ALASKA POWER AUTHORITY Table 1. Tentat1ve Schedule for Act1v1t1es to be Conducted w1thm Lake Clark Nat1onal Park F1sh Aer1al Schedule* and Ground Surveys 31 May-2 June X 21-23 June X 12-14 July X 2-4 August X 23-25 August X 13-15 September X 4-6 October X Act1V1ty W1ldl1fe V1sual Reconna1ssance X Hydrology Hab1tat Parameter Measurerrents X X *Act1v1t1es should only requ1re one day dur1ng each schedule per1od 10-57 10 5 Northern Alaska Env1ronmental Center 10 5.1 Correspondence A copy of a December 13, 1982 letter rece1ved from Er1c F. Myers of the above referenced agency 1s repro- duced on the follow1ng e1ght pages 10.5.1 1 Response A copy of the Power Author1ty's reply, dated December 30, 1982, 1s reproduced on the two pages follow1ng the reproduct1on of Mr. Myer's letter 10-58 \ l I I I I I ,, I ~ I I I I I I \ ~ '--J \ I \ I 1 \ ,__::: t • ~ I t Northern Alaska Environmental Center 833 Gambell Streeet -Su~te B Anchora~e. Alaska 99501 Mr Er~c Yould Execut~ve D~rector Alaska Power Author~ty 334 West 5th Avenue Anchorage, Alaska 99501 Dear l-4'r. Vould (907) 277-6814 13 December 1982 lBI:!Ce(VeQ ' [EC l 61982 ~ f.OWER !tUTHOIIJtt I am wr~t~ng to exoress for~ally my great concern about the orogress and adequacy of the Lake Chakachamna feas~b~l~ty stud~es As you well know, the Chakachamna oroJect ~s the most s~gn~f~cant and l~kelv hydro alternat~ve to Sus~tna and a comorehens~ve evaluat~on of th~s ootent~al hydro opt~on ~s central to the on go~ng Ra~lbelt power stud~es W~thout the comm~tment of the APA to undertake and execute the necessary ~nvest~rat~ons to assess proJect feas~b~l~ty at the level of deta~l requ~red for preparat~on of a FERC l~cense aopl~cat~on, the APA w~ll preclude ~ean~ngful cons~derat~on of the Chaka- chamna opt~on As a result of attend~ng the recent December 9, 1982 ~nter agency br~ef~n~ on the status of the Chakachamna stud~es, ~t ~s apparent that the APA ~s not honor~np ~ts nubl~c comm~tment to cont~nue the Chakachamna ~nvest~gat~ons ~n a substant~ve and t~mely fash~on It ~s now ev~dent that the FY 83 fund~ng of S800,000 allocated by the APA Board to the Chakachanna stud~es ~s ent~rely ~nsuff~c1ent to address the outstand1ng quest~ons about proJect feas~b1l1ty and that th1s w~ll have the effect of d~scount~ng the v1ab1l~ty of the Chakachamna oot1on as part of the FERC Sus1tna proceed1nfs The Northern Alaska Fnv1ronmental Center has, over the oast three years, repeatedly c1ted the need to Move forward u1th the Chakachamna ~nvestL~at~ons 1n an appronr1ately ag~ress1ve fash1on so that the Chakachamna and Sus1tna oot1ons can be cons1dered on an equal bas1s That 1s why last June I urped the APA to allocate the full $3 3 M1ll1on necessary to under- take the ful~ scone of feas1b1l~ty stud1es requ1red to assess the Chakacha~na sLte At that June Board ~eet1ng vou reoresente0 that ~800, 000 v70uld be suff1c1ent to cont1nue the· evaluat1on of the Chakacramna opt1on At the December 9 1nteragency meetLnr,, hm-1ever, APA proJect Manager Er1c ~1archep1an1 Made reneated reference to "bud~etarv constra1nts" and the fact that he has not "had the level of fund1ng necessary to sunnort" a feas1- b1l~ty level rcoort The Northern Alaska F.nv1ronmental Center cont1nues to be deeply concerned that a lack of coMm1tment on the part of the APA to conduct the aporonr~ate eng1neer1ng, 10-59 Mr Yould, p 2 geotechn~cal, and env~ronmental stud~es of the Chakachamna s~te w~ll result ~n a preJud~ced evaluat~on of Ra~lbelt elec- tr~cal opt~ons Prec~sely the s~tuat~on we had hoped to avo~d ~s now be~ng real~zed The l~m~ted work done by Bechtel and Woodward-Cl je has accom- pl~shed l~ttle more than conf~rm the fact that Chakachamna ~s very attract~ve econom~cally (relat~ve to Sus~tna) and that the s~te supports a s~gn~f~cant f~shery resource (as does the Sus~tna). The work by Bechtel/Woodward-Clyde, however, w~ll not y~eld a level of assessment necessary for preparat~on of a FERC l~cense appl~cat~on as stated by Mr Marcheg~an~, nor w~ll the Bechtel/Woodward-Clyde work prov~de a suff~c~ent bas~s for co~par~ng the relat~ve econom~c and ev~ronmental mer~t of these proJects as requ~red for the FERC/NEPA-EIS process It seems ~nescapable that the subm~ss~on of a Sus~tna l~cense appl~ca t~on ~n the f~rst quarter of 1983 (as presently planned) would, on ~ts face, be def~c1.ent u1 th~s t.egard The Northern Alaska Env~ronmental Center shares your oft stated concern for the potent~al f~shery ~mpacts that could attend de- velopment of the Chakachamna s~te, as we are concerned w~th the myr~ad ~mpacts that would be assoc~ated w~th development of the Sus~tna bas~n Ne~ther of these proJects should enJoy bl~nd support and both must be carefully evaluated as part of a com- prehens~ve Ra~lbelt power plann~ng effort It ~s lamentable that some perce~ve the more modestly scaled 330MW Chakachamna proJect as a t~reat to Sus~tna Espec~ally at a t~me when electr~cal demand proJect~ons are dropp~ng dramat~cally and future load growth ~s clouded w~th great uncerta~nty, such a narrow nerspec- t~ve contr~butes l~ttle to the need for caut~ous cons~derat~on and prudent plann~ng to develop an opt~mal supply strategy for the Ra~lbelt As you well anprec~ate, the quest~onable need for a mass~ve proJect l~ke Sus~tna requ~res careful evaluat~on of more flex~ble capac~ty supply strateg~es wh~ch could ~nclude a comb~nat~on of short-term benef~ts from comb~ned cycle combus- t~on turb~nes us~ng natural gas and long-term benef~ts from ~ more modestly scaled hydro proJect l~ke Chakachamna For these reasons we formally ask the APA to defer f~l~ng of the Sus~tna l~cense appl~cat~on ~n February so that (1) deta~led evaluat~on of the Chakachamna ont~on may be ~ncluded ~n the appl~cat~on and (2) the f~shery and w~ldl~fe ~mpacts that would be assoc~ated w~th e~ther proJect may be better understood We ask, moreover, that the APA ~~ed~ately ded~cate the necessary f~nanc~al and personnel resources to ungrade the Chakachamna study effort to that of a true feas~b~l~ty study and so that the 1983 f~eld season may be as product~ve as poss~ble At a very m~n~mum, th~s should start w~th the conven~ng of an ~nter agency steer~ng comm~ttee for the Chakachamna nroJect analogous 10-60 I I l ~ ' r\ I ' I II I I I I I \ I f I I \. i I !J ~I, I \ ) -l /; I ) /~ \ I "' I \ ,c_, I I I I ' -=-I~ I ~-~ ,._, I \ J I_ j Mr Yould, p 3 to the Sus~tna Hydro Steer~ng Comm~ttee In the absence of such act~on on the part of the APA to ~nsure a thorough analys~s of Ra~lbelt power alternat~ves, we feel that vou w~ll Jeopard~ze the Sus~tna l~cense appl~cat~on and subJL-t the ent~re process to unecessary delay The Chakachamna Alternat~ve The Northern Alaska Env~ronmental Center has not been alone ~n ~ts effort to draw attent~on to the need to carefully cons~der more modestly scaled power opt~ons such as Chakachamna as an ~ntegral aspect of formulat~ng a respons~ble plan to meet future Ra~lbelt power requ~rements Indeed, the External Rev~ew Panel of ~nternat~onal experts reta~ned by the APA to prov~de an ~n dependent assessment of the Sus~tna proJect, ~n formal test~mony to the APA Board, strongly recommended that your agency ~dent~fy v~able power alternat~ves ~n the event that (1) Sus~tna ~s delayed or (2) the demand forecasts change Prec~sely the latter c~rcum stance has emerged w~th current Battelle energy proJect~ons for the year 2010 as much as 447. lower than the ISER forecasts used by Acres ~n ~ts development select~on analys~s wh~ch led to the adopt~on of the Watana/Dev~l Canyon scenar~o See Table 1 Th~s adv~ce was reflected ~n the letter sent by the APA to the State leg~slature (Apr~l 26, 1982) wh~ch recommended that the qhakachamna and North Slope gas alternat~ves be thoroughly ~n vest~gated. The APA Board spec~f~cally ~nd~cated that FY 83 costs to cont~nue the Chakachamna feas~b~l~ty stud~es was on the order of $3 3 I'l~ll~on The Pol~cy Rev~ew Comm~ttee, charged w~th the respons~b~l~ty of manag~ng the Battelle Alternat~ves to Sus~tna study, concurred w~th these assessments and also supported FY 83 fund~ng to assess the Chakachamna opt~o, ~n deta~l along w~th add~t~onal ~nvest~ gat~on of the North Slope gas and Beluga coal opt~ons More recently, the D~v~s~on of Budget and Management noted cer- ta~n def~c~enc~es ~n the FY 83 stud~es respect~ng the APA staff desc~s~on not to undertake necessary geotechn~cal stud~es The D~v~s~on of Budget memo (August 19, 1982), d~str~buted to the full Board by Dr Ronald Lehr, noted that the l~m~ted scop~ of the FY 83 Chakachamna stud~es "may result ~n a (Sus~tna) FE"?C l~cense appl~cat~on next spr~ng wh~ch ~s ne~ther complete nor adequate " Fund~ng I As you know, when the leg~slture adJourned, ~t had appropr~ated $25 6 m~ll~on for the cont~nuat~on of the Sus~tna/ Ra~lbel t power stud~es At the June 24, 1982 APA Board meet~ng cons~derat~on 10-61 Mr Yould, p 4 was g~ven to the ~ssue of subm~tt~n~ a FERC l~cense appl~cat~on ~nclud~ng the role that the Chakachamna feas~b~l~ty study played ~n the overall evaluat~on of Ra~lbelt power opt~ons I myself took the opportun~ty at that t~me to make a statement to the Board and urged that the full $3 3 m~ll~on necessary for the Chakachamna stud~es be ded~cated to that purpose from the $25 6 m~ll~on ava~lable To my great d~saoo~nt~ent ~t was your recommendat~on to the Board that only $800,000 be allocated to the Chakachamna ~nvest~gat~ons It was your content~on that $800,000 was suff~c~ent to carry the stud~es forward As noted ~n the recently prepared APA FY 84 budget proposal relat~ve to the Chakachamna proJect, the "FY 83 funds are com~ng from the Sus~tna funds s~nce Chakachamna ~s cons~dered as an alternat~ve to the Sus~tna ProJect " The budget document goes on to state that the FY 83 ($800,000) phase of ~nvest~gat~on "w~ll see a threshold level of env~ronmental ~nvest~gat~on and add~t~onal eng~neer~ng stud~es to conf~rm the construct~on cost est~mate and cost of power " It ~s not clear to me what a "threshold level" of evaluat~on means ~n l~ght of the data that has been gathered by Bechtel/\-loodward- Clyde and wh~ch was presented at the December 9 ~nteragency meet- ~ng Clearly, the proJect ~s st~ll econom~cally attract~ve, ~n fact even more so now than when Acres d~d the~r feas~b~l~ty work on Sus~tna as a result of downward rev~s~ons ~n cap~tal cost est~mates by about $0 22 b~ll~on due to the ab~l~ty to use state- of-the-art tunnel bor~ng technology As for the env~ronmental work ---wh~ch has focused exclus~vely on the f~shery ---there ~s l~ttle to be concluded beyond the fact that the McArthur and Chakachatna dra~nages support a s~gn~f~cant f~shery resource on the bas~s of very l~m~ted escapement data The "threshold" level of data developed by Bechtel and Woodward-Clyde has conf~rmed the fact that the Chakachamna alternat~ve ~s as much (~f not more) of a Ra~lbelt power alternat~ve due to (1) downward rev~s~ons ~n expected cap~tal costs and (2) downward rev~s~ons ~n expected load growth The Need for Add~t~onal Invest~gat~ons At th~s po~nt, the Northern Alaska Env~ronmental Center ~s very concerned that the Chakachamna stud~es be expanded substant~ally ~n scope We urge that the APA ~mrnead~ately comm~t the f~nanc~al resources presently at ~ts d~soosal toward the development of a comprehens~ve f~as~b~l~ty study of a qualLty and deta~l equal to t~e Sus~tna stud~es The scope of ~nvestLgat~ons should ~nclude a much more deta~led exam~nat~on of the Chakachatna tunnel alter- nat~ve, espec~ally ~n l~ght of the recent f~nd~ngs regard~ng tunnel bor~ng technology (Wh~le the Chakachatna tunnel alter- nat~ve may not be as attract~ve as the ~cArthur tunnel scenar~o, ~t offers the d~st~nct advantage of oerha~s avo~d~ng altogether ~mpacts to the HcArthur draLnage ) It ~s ~mperat~ve that th~s effort be ~n~t~ated ~m~ed~ately and aggress~velv so that the Chakachamna hydro opt~on can be cons~dered on a par~ty basLs w~th 10-62 I l I \I I \ I _J ' \ I I I I l 'I I I l ! I ' c { I I \ I I I \ \ I I I_) 1 I \ Mr Yould, p 5 Sus~tna It was clearly ev~dent from the comments made by the resource agency personnel at the December 9 meet~ng that there ~s a great amount of work to be done between now and the po~nt when we could ach~eve such a level of comparab~l~ty Th~s ~s part~cularly d~sturb~ng ~n look~ng back thrnugh the November 1981 Inter~m Report on the Chakachamna stu Les wh~ch was very expl~c~t about the fact that the consultant was pro- v~d~nf; serv~ces "for uerform~ng a feas~b~l~ty study and for pre- par~ng an appl~cat~on for a FERC l~cense to construct" the Chakachamna proJect The "1982 Work Plan -Env~ronmental Stud~es" c~rculated by the APA to the resource agenc~es almost exactly one year ago was equally expl~c~t w~th regard to the overall obJect~ve be~ng to prepare the necessary env~ronmental exh~b~ts to accompaPy an ~PA l~cense appl~cat~on Unfortunately, th~s "paper comm~tment" has not been supported monetar~ly As currently planned, Bechtel/Woodward-Clyde w~ll ~ssue the~r f~nd~ngs at the end of February and the study at that po~nt w~ll not be of suff~c~ent qual~ty to make a clear determ~nat~on about proJect feas~b~l~ty It ~s perhaps not ent~rely ~ron~c that the same month ~s targeted for subm~ss~on of the Sus~tna FERC l~cense appl~cat~on Further work on the Chakachamna feas~b~l~ty study w~ll then be dependent upon the vagar~es of leg~slat~ve appro- pr~at~on dur~ng a t~me when ~ncreas~ng pol~t~cal pressure ~s be~ng orchestrated to "pour concrete " The Need for a New Plan of Study I do not mean to ~mply that even an unl~m~ted budget for the Chakachamna stud~es as of last June could have y~elded a com- pleted feas~b~l~ty study by "late w~nter of 1983" as was pro- posed ~n the "1982 Work Plan -Env~rot1I'lental Stud~es" document The 1982 ~Jork Plan was def~c~ent ~n many regards, as po~nted out ~n the comments prepared by ADF&G (February 18, 1982), USF&WS (March 5, 1982, March 12, 1982) and NMFS (February 18,1982) much rema~ns to be done to work out a comprehens~ve Plan of Study to ~dent~fy and e~ecute essent~al f~eld stud~es However, a larger budget last June and resolve on the part of the ~PA to ~n~t~ate the necessary ~ntera~ency urocesses would have advanced the stud~es much further than they are today W~th the l~m~ted fund~ng, the 1982 Work Plan and agency coMments were "set as~de" (to use ~r Marcheg~an~'s words) and a scope of work negot~ated between the APA and Bechtel/Woodward-Clyde w~th out the appropr~ate ~nvolvement of other resource a~ency personnel. the result ~s that wh~le we do know somewhat more about the proJect s~te, a great deal of money and, more ~mportantly, t~me has been wasted Based on the l~m~ted ~nformat~on currently ava~lable, the 330~ Chakachamna proJect stLll appears to be very attract~ve economLcally 10-63 Mr Yould, p 6 w~th an est~mated cap~tal cost of approx~mately $1 23 b~ll~on (Bechtel/October 1982 Progress Reoort) As you noted ~n re- cent remarks to the Alaska Env~ronmental Assembly (November 13, 1982) the Chakachamna proJect ~s very compet~t~ve w~th Sus~tna and qu1te poss~bly the more attract~ve econom~c cho~ce Th~s ~s pa1 _cularly so because a proJect the s~ze of Chakachamna would not be vulnerable to the uncerta~nt~es of load proJect~ons (~e , we can reasonably assume the need to replace 330MW of thermal capac~ty but cannot necessar~ly assume the need for all 1600MW's offered by Sus~tna) Wh~le you have acknowledged the econom~c mer~t of Chakachamna, you have expressed great concern for the f~shery ~mpacts that could attend development of the proJect Th~s sent~ment ~s reflected ~n the Acres feas~b~l~ty reoort where Chakachamna was not ~ncluded ~n the "base case" plan because "~t may have a substc>rt~al f~shery ~mpact" and because "stud~es to date have been ~nsuff~c~ent to determ~ne expected cap~tal costs w~th prec~s~on" (Acres/Summary Report, March 1982, p 7) Notw~thstand~ng the substant~al expend~tures by APA to Acres, the same general observat~ons may be made about the Sus~tna proJect The Sus~tna related f~shery resource ~s only d~mly understood at th~s po~nt w~th only the ~n~t~al phases of a bas~c 5-year study program complete Recent correspondence to your agency by USF&WS (October 5, 1982) and NMFS (October 15, 1982) descr~bes the more ~mportant f~shery ~ssues that rema~n ent~rely unresolved The fact that the 1982 (second year) f~eld data w~ll not be ~n cluded ~n the l~cense appl~cat~on h~ghl~ghts further the severe l~m~tat~ons to our current understand~ng of the potent~al ~mpacts to the Sus~tna bas~n f~shery More succ~nctly, at present the Federal and State resource agenc~es are only now ~n the process of descr~b~ng the ex~st~ng resource and are far from understand~ng the ~mpacts assoc~ated w~th post-proJect cond~t~ons Resoect~ng conf~dence ~n the Acres cap~tal cost est~mates for Sus~tna, the fact that an ~ndependent cost est~Mate by Ebasco y~elded a $0 36 b~ll~on d~spar~ty clearly ~nd~cates that t~e "prec~s~on" of Acres Sus1.tna cost est~mate ~s somewhat susoect F~nally, I would note that the m~nutes of the June 24th APA Board meet~ng reflect your comment that "Sus~tna must be the best alter- nat~ve before the FERC w~ll ~ssue a l~cense '' It ~s our hooe that the FERC process w~ll, ~n fact, ~nsure that the Chakachamna alternat~ve ~s ~nvest~gated adequately and the best Ra~lbelc.~ower alternat~ve developed To that end, we urge the APA to defer ~ts Sus~tna l~cense appl~cat~on and move forward ~~ed~ate1y w~th expanded Chakachamna stud~es so that these two maJor alternat~ves may be cons~dered on a comparable bas~s s~ncerely, i;;;?J~ 10-64 I I I l I I I I I I I I I I I I I I _, I : I I ( I I f \_ I ' { I ' i l j I r- 1 I ' I ( Mr Yould, p 7 cc APA Board USF&WS NMFS ADF&G ADNR Sus~tna Hydro Steer~ng Cornrn~ttee Quent~n Edson, FERC s~erra Club Alaska Center for the Env~ronment Trustees for Alaska Governor Sheff~eld 10-65 Year 1980 1985 1990 1995 2000 2005 2010 Table 1 DECLINING LOAD GROWTH PROJECTIONS ''Med~um'' Load Growth 1980 1982 ISERl Batte11 e2 2790 2551 3570 3136 4030 4256 5170 4875 6430 5033 7530 5421 8940 6258 ProJect~ons/GWh Rev~ sed Battelle3 2551 3000 3391 3884 4010 4319 4986 Notes 1 Used by Acres for generat~on plann~ng stud~es for development select~on, Acres feas~b~l~ty study Table 5 6 2 Battelle "base case" • Battelle CoMment Draft Table A 12 3 Rev~sed Battelle forecast, Prologue Table 3 (Draft) 10-66 "' I ~ ... ( I I I -j I' I \ I -- ) ~ I I I l -" ~ I ~I / I I I I r 1 I Lj {~ I I I (, I t II ~~ I \ I I { ALASKA POWER AUTHORITY 334 WEST 5th AVENUE ANCHORAGE, ALASKA 99501 ~~CE~VEtD JAN 4 1983 ft. T~ LODER Mr. Er1c F. Meyer Northern Alaska Env1ronmental 833 Gambell Street Su1te B Anchorage, Alaska 99501 Dear Mr Meyer Center Phone (907) 277 7641 (907) 276 0001 December 30s 1982 Please reference your letter of December 13~ 1982 1n wh1ch you suggest the Alaska Power Author1ty defer the f1l1ng of the FERC l1cense on Sus1tna We w1ll not defer the f1l1ng of the Sus1tna FERC l1cense appl1cat1on. The Power Author1ty bel1eves the stud1es be1ng done on the Chakachamna proJect to date are more than suff1c1ent to fulf1ll all FERC requ1rements for the study of alternat1ves for Sus1tna l1cense appl1cat1on. Furthermore 9 the Chakachamna proJect 1s not 1tself an alternat1ve to Sus1tna~ but rather an element of a larger alternat1ve scenar1o that 1ncludes coal and natural gas f1red generat1on. Over $1 8 m1ll1on has been 1nvested by the Power Author1ty and the Governor•s off1ce 1n evaluat1ng the Chakachamna hydroelectr1c potent1al Ne1ther the Sus1tna Feas1b1l1ty Study nor the Battelle Alternat1ves Study found the Chakachamna proJect to be the preferred Ra1lbelt power generat1on alternat1ve At the same t1me, however, the potent1al for eventual contrary f1nd1ngs was recogn1zed. New 1nformat1on on Chakachamna costs, Sus1tna costs, or load forecasts could conce1vably reverse the f1nd1ngs Therefore, add1t1onal work to explore money sav1ng construct1on concepts was deemed adv1sable The necessar} funds were taken from the Sus1tna appropr1at1on A FY 82 study plan was drafted wh1ch addressed the pr1mary area of concern affect1ng feas1b1l1ty proJect cost F1shery 1mpact was also deemed 1mportant, as m1t1gat1on measures (m1n1mum flows and f1sh passage) could potent1ally 1mpact proJect output and cost The current program has three maJor components 1) f1sh passage 1nto and out of the lake, 2) enumerat1on of the f1shery resource, and 3) the appl1cab1l1ty of tunnel excavat1on by means of a tunnel bor1ng mach1ne (Th1s poss1b1l1ty represents the source of the greatest uncerta1nty 1n the cost est1mate.) The f1sh passage fac1l1ty analys1s has 1nvolved the development of a structure wh1ch would perm1t passage of f1sh at var1ous lake levels w1th grav1ty flow In order to prov1de grav1ty flow through the fac1l1ty, the proJect would requ1re a small 50 foot rock f1lled dam at 10-67 . ' Mr Er1c F Meyer December 30, 1982 Page 2 the outlet of the lake. Th1s structure would probably requ1re cont}nuous ma1ntenance due to the movement of the Barr1er Glac1er The f1shery enumerat1on program has collected data cont1nuously between July and November. In add1t1on, there w1ll be a w1nter survey and a spr1ng survey The program w1ll est1mate the seasonal d1str1but1on, hab1tat abundance, and numbers of f1sh. ThP est1mate of f1shery 1mpact w1ll be updated based on th1s add1t1onal data. Further work such as an 1nstream flow assessment would be requ1red to fully evaluate proJect 1mpacts and m1t1gat1on measures, but such 1mpact work cannot effect1vely beg1n unt1l a year of base l1ne data collect1on 1s accompl1shed As you are aware, a representat1ve rock sample has been acqu1red near the McArthur power house s1te and has been sent to the Robb1ns Company Test1ng Laborator1es 1n Seattle, Wash1ngton. The Robb1ns Company has reported that the rock 1s s1m1lar to the rock found at the Kerckhoff proJect 1n Cal1forn1a, where a 24 foot d1ameter tunnel bor1ng operat1on has been 1n sat1sfactory progress dur1ng the past year. The test data from the rock analys1s has generated 1nformat1on wh1ch was ut1l1zed to est1mate the cost of us1ng a tunnel bor1ng mach1ne rather then the convent1onal dr1ll and blast method. The est1mate has reduced the cost of the proJect by approx1mately $200 m1ll1on In summary, the Alaska Power Author1ty has pursued the Chakachamna ProJect w1th the appropr1ate d1l1gence, g1ven that stud1es to date have shown 1t not to be the preferred Ra1lbelt power generat1on alternat1ve The current stud1es are more than adequate to fulf1ll all FERC requ1rements for the study of alternat1ves. cc Robert Loder, Bechtel Wayne L1fton, Woodward/Clyde Kenneth Plumb, Secretary, FERC W1ll1am Wakef1eld, FERC Charles Conway 10-68 S1ncerely, -;--.. ~ Er1c P Yould Execut1ve D1rector "'I I ! I I I I I I I I I I I l ~ APPENDIX TO SECTION 4.0 POWER STUDIES \ \ l --~ PRCJECT l~R7°"01 INSTALLED CAPACITY q(JJ"J VW A~~UAL ~LA~T FACTfP OVERLGAC fACTrfl DO PLA~T EFFJCif~CY .1350 FRICTIC~ LC~S COEFFiflE~T 000002370 640 .620 .610 INITIAL LAKf STfRACE 4P)3200. AC-FT MJNifiUpl LAKE STfRAG[ O. AC-FT ~AXI~Upl LAKE STCRAGE 403~200. AC-FT CH~Vf,Cf Al1 ~1 A Pf<LluECT CPfRATION STUDY 1/l,,tl~rr,p[(bTEL CIVIL&r INERALS INC.,SF. ALASKA POWEP IUTHORITY ill TERt-.ATIVE A I-ICARTIIUR SHIRT TUNNEL, 11/0 FISt-RELEASES 64L .100 .aoo .920 1.ooo I- I DATE 110581 --" ~ PAGE 1 fQ) ~ ~ f) f) t) •) I) I) f) () j <) 0 (_) 0 _) 0 c~•KAC~AMNA PROJfCT OPERATION STUDY t II ,ti&CF oDECIITEL CIVIL&f-'INERALS 11\C oSF. PROJECT 141'79~01 ALASKA POYER AUThORITY DATE 110581 PAGE 2 ALTE~NATIVE A MCARTI'UR SHORT TUNNEL. W/0 FISI-RELEASES PE"SERVCIP ~T(l"ff[-r LfVATJI 1\-AilfA Af-Fl FrrT Affit r 7 ( L o c. 2J2" 7~ r A 1 r. 730() 77 130C 27200 7 f ( 2£. r r 0 111000 r 2 r !:f.? G. ----::'41ron I > C • nn. 39HO 0 • 1'40. 1'270. 57::'~oc Ff.'J 9::'80 769"00 !l~O. 10400. Cf1f2CO 9CC 115°Co 1224000 0 2 c 11%0 f) 1'tf7~oc. "4 () 1?32(1. 1717000 9EO 1 ?1'50 1"73QOC oer 1?980 ?2 7 6GOO 10C'Oo 1 7 ?1'0. 2504GOO 1 0.< 0 13520. 2771i~oo. 1 ()4 0 1374G. 3053000 1060. 13q6o. 333"000 lOHC. 14170. 3E2COOO 11 c c 14390 0 3"1~ooo. 11:?C. 14620. '103~200 11::-e l'i212 0 T t ILYATER-FLOII R[LATICI\SPIP ------- FrET fFS 0 210 0. 21 c. 100000. 0 MOI\THLY I'TNII"UM 11\STRFAI' FLOIIS IN CF S. 0 () . ~. 0 0 0 0 0. 0 0 0. 0 0 MONT'-'LY DIVERSifll RFQUIPUIENT5 HI CF S 1). (' n r c 0 c 0 c c 0 MONTIIL y RLSFRVC1IP f V ~ P t R 4 T I (l r' ItJ I ~I(' It E <; 0 o. o. 0 0 0 o. 0 G 0 0 0 0 0 L- PROJECT 14fl7C,' UJ 11\FLOIIS Tfl Tllf lti'E If\ CFS YEAR 6 7 A a 1 0 11 J f.'' ~tro f177 633 4<"8 ~H 419 'J, B 'i ~ 1 • 534 4A'i 497 'ill 877 364 FFr ~c1 rpc:, ~ 'll ~"7 4~5o ?1". 3~E 449 'ilO 41'E 'i04 430 "!'". 21" 2f-7o 47C 471 315. 332. 337 350. 384. 467. "00. 550 lf04 550. 267. APR ~'33 346 470 ~37o 477. 398 410 880. 630 652. 899 536 eoq 337 ------., I fl trfCI Afi,NA PHOJE.CT OPERATIOfll <;JUDY I /I • ifO \F 11 E C f-. T F l C I V I L & f' I N [ R fll S I N C • • Sf • ~L~SI<A POWEr /•UTt'rP I TY DATE 110581 ~LHPfiATIVE A f'CARTIUP SHORT TUNNEL, 11/0 FISt-RELEASES I' f y ~f-7,7 1 fIll 12t5. 1PC1e lP""O 1286 1803 2 03 0. 299f- 1941l. 2265. 2076 363 7. 1265 JU"J f:!'37 7"83 7925. 47"'J5. 80G3 ~490. e 012. 8761. 7808. --9271. 6789 7251. 9271. 3'190. JUL 11209 12808 1314° l31'49o 10700. 13046. 1C303o 14931. 13117. -12510. 1('360 12307. 149"'i1o 10303. AUG 9337 10899. 10411. 12208. 11798 10516. 997'1. 15695 11257. 72.97 ·- 7986. S[P 31'1'i 6225. 5542 58lf7o lf246o 10802. 6608. 6191. 2793. 2793. 273lf. 10671. 5175 15695o 10802o 72.97. -2.73'1. OCT 1439. 1'i86o 1197. -2056·--- 12'15. 211'1 0 1953. 20'10. 976. 3057._ 1359. NOV 799. 8'13. 863. 930. 909. 597. 910. 1215. 689. 12.15. 742. 1729. 883 3057. 1215 -976. -597. DEC 870. 696 613 710. 662. '166 313. 571. 612. 5'11. 460. 592. 870. 313. PAGE AVEYR 3220. 3767. 3590 3587. 3'124 3641. 34'i9. '1473 3532. 3396. 2929 3547. CALYR 1960 1961 1962 1963 196lf 1965 1966 1967 1968 1969 1970 ( ·~ "I I - ~ (J 0 I ~ t] 0 I) l)t ~ ') () ') \) ~') I o.) 0 ...) I _J 0· ' ' C hf I' A C' I A 1-'1\ II PROJECT OPERATION STUDY 0 1-/II,II~CfoGECI-'TEL CIVIL&"IIJERALS H;C ,sr PROJfCT 1~li7"'C01 nASI< A P OlJfR ~UHiflRITY DATE 110581 PAGE ~ 0 ALTfRIIJA T I VE A MCARTI•UR SHORT TUNNEL, 11/0 FISI-RELEASES POlJER RELEA<;F II\ CFS ') YEAR JArl FER MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR ') 'il'l" 31'-80 3356. ;?C9:;> 2793 2635. ?530. 2597. 3079. 3282. 3910. '1288. 32~6 1%0 2 '1('14 3/t 7 7 3443 31~9 29~1. 2771 2">91. 2597. 2851. 3282. 3910. '1288. 3310. 1961 3 4r 14 31'7 7 3 5 'i6 3149 2Cl4}. 2771 .c656. 2659. 2851. 3282. 3911. '1'103. 3338. 1962 0 4 'ICI4o 3r77 3536. 3149. 2"'41. 28'15a 2656. 265'3. 2851. 3282 •• 3910. '1288. 333'+• 1963 ') 4 (• }4 3117f 353f.o 314'1. 2"'41 2771 i-656. 265°. 2851. 3282. 39Uo '1'103. 3336. 196~ 6 ~C14. 7 r77. 3536. 3149. :? 94 1 • 2fl45. 27?4. 2724. 2851. 3282. 3°10. 4288. 3345. 196" f) 7 4014 3877 3536. 3149. 2941. 2771 2656 2659. 2851. 3282. 3910o 4288. 3328. 196€- A 4014. 3P.77. 35"16. 3149. 29'11 2771. 2591. 2597. 2851. 3282. 3910. 4288. 3317 196 7 9 4014. 3f!7f.o 34'14. 3149. 2Pf>'io 2771. 25<11. 2597o 2851. 3282. 3911. 4'103. 3313o 1°68 () 1 0 4 0 14. 3877. 35"1f>o 3149. 2941. 2771. 25°1. 2659. 2851. -3282. 3910. -'1288. 3323. 1969 1 1 '1014 ..,877. 3536 "11~9 28(,5. 27710 2656. 2659. 2920. 3363. 4013. 4405. 3352 • 1970 0 t'EAI\ 39°6 "1'~9. 3503. 3135. 291~. 2772. C.627 2643. 2878 3289. 3920. 4330. 3322o I' AX 4014 3~77 3536 31'1o. 2 G41o 2845. ';724 2724. 3079. 3363. '+013. '1'105. 3352 0 I'll\ 'ill!' "6l'O. 3356. 2'3'32. 279'i 2635. 2530. 2597. 2851. --3282 0 -3910. 4288. 324E.o ') 0 0 c) --------- 0 1..) L) Q Q 0 0 liD ,Q I _) l_ _j .., __ .-! l~-- l_ l '------ ' r-~l c-_] r'--r~-~ ,~ -I I I I I I L ~ _j -~~J L L-~ I~ CHAKACI A,..NA PROJECT OPERATION STUDY 1-/llollf.CF 9BECJ-,Tfl CIVIl&MHJfRALS INC •• SF. PROJECT 14r79r 01 ALASKA POIJER /UTI'ORITY DATE 1105B1 PAGE 5 ALHRI\'ATIVE A MCARTI UR SHORT TUNNElo W/C FISI-RELfASES SPill II\ CFS YEAR JAN fEB MAR APR rAY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR 1 0 0 0. 0 r 0 1 41 7. 6740. 66. o. o. o. 685. 1960 ? 0 0 o. 0. 0 o. 0 2437. 3374. o. o. o. 4 84. 1961 3 0 0 0 0. 0 0. 0. 12lf8 26q1. 0. o. o. 328 1962 " 0 o. o. o. o. o. o. ---o. 2342. ---Do-0. -0. 195. 1963 "' 0 0 0 0. n o. o. 874o 1395 0. o. 0. 189. 1964 6 0 IJ. o. o. 0 0. o. o. 3444 o. o. 0 287 1965 7 0 0. o. 0. 0 0. 0. o. 1882. o. Do o. 157 1966 A 0 o. 0 o. 0 o. o. 10188. 33l!Oo o. o. 0 1127. 1967 q 0 0. o. o. 0 o. o. li580o o. o. Do o. 382 1968 10 o. o. o. Do---0. o. --0.-o. o. ---Do---~-D~ o. Do 1%9 11 0 0 0. o. o. 0. o. o. 0. o. o. 0. 0 1970 l'.EAN 0. 0 o. o. -o. o. 129. 2370. 1685. o. 0. o. 349. !'AX 0 o. 0. 0. 0 o. 1lf17o 10188. 3ljljlj. 0. o. 0. 1127 Mit.. o. 0 0 o. o. o. 0 ·-Do ---0. o. __ Q_. -__ o .. o. o. 0 0 J ' ) CHAKACHAMNA PROJECT OPERIIT ION STUDY ~/HoH&CfoBECHTEL c I VJLUil NERALS INCeoSF. PROJECT 1H79(l01 ALASK~ POI.ER 1\UTHOR ITY DATE 11D581 PAGf 6 ALHRNATIVE A MCARTbUR ShORT TUNNEL, lol/0 FISt-RELEASES FISh RflF A<;E IN CFS ------ YEAR Jl\1, FEE' f'AR APR MAY JUN JUL AUG SfP OCT NOV DEC AVEYR CALYR 1 0 0. 0. 0 0 D. o. D. D. o. o. De D. 1960 2 o. o. o. D. o. Do o. o. o. o. Do Do D. 1961 3 0 0 o. o. 0. 0 o. o. 0. D. o. D. D 1962 4 0. o. o. 0. o. --0. o. o. o .. --0. -0 0 De D. 1963 '5 0 0 0. D. o. o. D. Do D. Do o. o. 0. 1964 6 0. 0. 0. o. D. D D o. o. D. o. D. D 1965 7 o. 0. 0 0. 0 o. 0. 0. o. D. o. Do 0. 1966 R 0 o. o. o. D o. 0. D. o. D. D. D. 0 1967 9 (') 8 0. D. 0 0. 0. 0. Do De Do D. o. 1968 1 0 0 0 o. o. o. o. 0 -0. D. -D._ __ o. _ --D. o. 1969 11 0 0 o. 0. 0 0 0 0. D. Do D. o. D. 19 7 0 f'EAN 0 0 0 0. e o. o. 0. 0. o. D. 0. D f'A)( 0 c 0 0 0 Do 0. 0. o. o. o. o. 0 f'JN 0 o. o. o. a. o. 0. --0. o .. o.-_o. Do o. 0 l) 0 0 0 I--___ l ' ;-1 =~-J _) L--'---- C II t If A C I A 11 N A PROJECT OPERATION STUDY h /II oil F. C f , ~ E C liTE L CIVIL&r'INERALS INC.,SF PRCJECT H879C01 ALA'>KA PUIJER AUTHORITY DATE llo5el PAGE 7 HTERNATIVE A MCARTI-!UR SHORT TUNNELt W/C FISt-RELEASES NET EVI•PORAT I ON IN A C-rT YEAR JAfJ FEr MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR 1 0 0. 0. Q 0. Oe o. o. o. o. o. 0. o. 1960 2 0 0 0 0 o. o. o. Oo o. o. o. o. 0. o. 1961 3 0. 0 0 0. 0. 0. 0. 0. o. o. o. 0. 0. 1962 4 o. o. o. o. o. ---Oo----o. o. -0 .. -0·----0·---o. o. 1963 ') 0 0. 0 0 0. 0. o. o. o. o. 0. o. o. 196'1 6 o. 0. o. o. o. 0 o. 0. o. o. o. 0. o. 1965 7 0 0 0 (1. 0. o. o. 0 0 0. o. o. 0. 0. 19'66 ll 0 0. o. o. 0. o. o. o. o. o. o. o. 0 1%7 Cl 0 0 0 o. 0 o. 0 o. o. o. o. 0. 0 1968 1 0 0 o. o. o. o. -0. o. o. o. o. _o .. -Do o. 1969 11 0. 0 o. 0. 0 0. 0. o. o. o. o. 0. 0 1970 i'EAN 0 0 • o. o. 0. o. o. o. 0. o. o. o. 0. I' A)( ~ 0 o. 0 0. o. 0 o. o. o. o. 0. o. I' TN 0 0. o. o. o. o. o. 0. -o. Do-_Q., ---o. o. t), 0 0 0 '' "' CI-IAKACI'M11\A PROJECT OPERATION STUDY 1/llollll.CroDECIIT~L CIVIL&MINERALS lNCooSFo ,, PPGJECT 1487'H01 ALASKA POIIER AUTHORITY DATE 110581 PAGE 8 AL TEP ~lA T IV[ A r-oc AR TI'UR SHORT TUNNEL, 11/0 FISI-RELEASES ., E.O.P STORAGE IN ACR£-FT "I YEAR JtN FrB I"AR APR MAY JUN JUL AUG SEP OCT NOV DEC AHYR CALYR ~1'?3~~1 :3f2<;">.1? ~4~<;~85. 3284714. -.~~U-37. "<58£:£:51. 403~200 4033200. 4033200. 3<;19884. 3734772. 3524610. 3698241. 1960 ·~ ;> "'33171/l 3149100. 29662G1o 279<;474. 2734289. 30l!4413. 3672605. l!033200. 4033200. 3928923. 3746l!29. 3525568. 3413767. 1961 3 3~17673. 3132"'8" 2943921.'27~4482. 2£:81l!21o 298(1093. 3633277 4033200. 4033200. 3905004. 37236511. 34"0595. 3388909. 1962 4 3?743'l9o 3078f97o ?880837. 2713484. 26l!3365. 2755850e-3407174o .399li312. 4033200 • 3557822. 3780505e 356050lj. 33li0029o 1963 "I 5 3336069. 3138121. 2941106. 2787081f. 2713763. 3030432. 3525033. 4033200. 4033200. 3907956. 37293li3. 31f99297o 3389131fo 196'l 6 3278243. 307'i077. 2878370 2714f47. 2612861. 2651264. 3285913. 3765014. 4033200. 35£:1388. 3764256. 3529253. 3295790 1965 7 33062c4o ~10'3(25. 2913717 2750708 2686245. 300H65o 3471855. 3921630. 4033200. 39!:11189. 3772981. 3528571. 3370665. 1966 8 33ll!404 312lf01lo ?930194. 2795151. 273'll28o 30'J'i546o 3854284. 11033200. 4033200. 3'3!:6838. 37%480. 3567933. 34366'37. 1967 9 3353<;~0 316031£:. 2977276. 2827358 0 2P35420o 3135142. 3782341. 4033200. II 029735. 3887950. 36962117. 3463126. 3'l31838. 1968 1 0 3?46131. "'057793. 2871108. 2722499. 26f1418. 30lf8183. 3658052. 3943232. 3939767. 3525938._3765579._3535188. 3364574. 1969 11 3318930. 3131""2 2947982. 2814070. 2777lll5 ~01E272 348°967. 38175011. 3806li40o 3683224. 31188577. 3246018. 3294813. 1970 MEAN 33'i464<J 31102"8" 297183'1 2817152. 2765612. "3032137. "'61°'127. 3967354. 11003776. 3507856. 3727166. 31197333. 3402223. r~ Ax 3!123331 3(2"312 343'3385 3284714 3:!36fiHo ~58H51o 403~200. 4033200. 4()33200. 3%1388. 37961180e 3567933. 3698241. f.' IN '2461".1. 30'1779:3 2871108. 2713484. 2fl?8&1. 26512£.4. 326'1913. 3765014. 3806440. 3Ee3224o-31f88577e 324&018. 3294813 1) 0 0 0 0 0 r- '~ PROJErT 14fl79v01 WATLR BALANCE YEAR JfN F[f I"AP APR 1 0 0 0 0. 2 0 Q 0 o. ~ 0 c c 0 4 0 o. o. o. 'i 0 Q. 0 0. 6 0 0 0 0 7 0 0. 0 0 fl 0 c (! o. 9 0 c 0 0 10 0 0. o. o. 11 0 0 o. o. MEAN 0 0 o. 0 I" AX 0 0. o. 0 I"JN 0 o. -o. -a. (~ I l -J Ct/rACPAM~A PROJECT OPERATION STUDY I /I' ,1, & r F • 0 F ('II T r L C I VI L & ~11 N r R A L S H• C • o SF • ~LA~KA POWER AUTHORITY ~LTEfHd1TIVE A I'CARTIIUh SIIORT TUNNEL, 11/C FIS~ RELEASES 1-'AY JUN JUL AUG SEP OCT 0 0. 0 0 o. 0. o. o. 0 0 0 o. o. 0 o. 0 o. 0 0 0 o. -0. u. o. o. Oo- c 0 0 0 o. o. o. o. 0 o. o. o. 0 0 0 0 0 0 o. o. 0. c. Oo a. o. 0 o. 0 o. o. 0 0 o. o. Oo o. Oo --De- 0 0 o. o. 0 0 o. 0 • 0 0 0 o. 0. 0. 0. 0. o. o. o. -o. ~ ---a. o. --~ 0. ~ o. _Q.. __ --, __ , -" (jl DATE 110581 PAGE 9 tl , NOV DEC AVEYR CALYR ') 0 0 o. 0. 1960 o. 0 0 o. 1961 Oo 0 0. 1962 ') _Q., 0 0 Oo 1963 0. 0 o. 1964 o. o. o. 1965 f) 0 0 0 196f> o. o. o. 1967 o. o. Oo 1968 f) o. o. o. 1969 0 0 o. 0 1970 I) o. 0 0. o. o. 0 () - _ __Q. o. o. () f) 0 ) ~) 0' _..) J ) ~ ) l_), 0 f' rl•~~ /.CHAMNA PROJECT OPfRATION STUDY 0 I /II o H & C F o BE C fJ T E L C I VI L& " I ~. E R A L S l!I.C .sF. PRCJECT 141\7'1 •01 ALASKA PO\.JER AUTf-lORITY DATE 110581 PAGE 1 0 0 ALTERNATIVE A MUR Ti'UR SHORT TUNNEL, IJ/0 FISt-RELEASES POiolrR II\ ~1lol ) YEAfl J A~' Ffll f'AR APR ~~ ~ y JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR -) 1 £40. 227. 203. 103. 1f.7. 162. 159. 167. 183. 209. 240. 261. 200 1960 2 ('40 ?27. 20~ 11?3. 167 162 159 167. 183. 209. 240. 261. 200. 1%1 3 24C ??7 203 183. 167. 162. 159. 167. 183. 209o 240. 261. 200. 1962 ') 4 240. 227 203. 183. 167. 162.. 159. 167. 183. 209. -2'10. -261. 200. 1963 5 24!1. 227. 203. 183 167. 162 159 167. 183. 209. 240. 261. 200. 1964 6 240 227. 203. 183. 16 7o 162. 159. 167. 183. 209. 2'10. 261. 200. 1965 () 7 240 227. 203. 183. 167. 162. 159. 167. 183. 209. 240. 261. 200. 1966 ll 240. 2?7. 203. 1£!3. 167. 162. 159. 167. 183. 209. 240. 261. 200. 1967 9 240 227 203. 1fl3. 167. 162. 159 167. 183. 209. 2'10. 261. 200. 1961! () 1 0 240 ?21. 203. 183. 167. -162. -159.----167. 183. __ 209._ 2.40._ 261. 200. 1°69 11 240. 227 203 183. 167. 162. 159. 167. 183. 209. 240. 261. 200. 1970 0 t-'EIIN 240 ?27 203. 1B~. 16 7 162. 159 167. 183. 209. 240. 261. 200. I' AX 240. 227. 203. 11'~. IF.7 162. 159. 167. 183. 209. 240. 261. 2Ci0. ') f-1IN ?40 ?27. 20~. 183 .. 167. 162. --159. 167. 183. 209o_-2.4 0 e _ 261. 200. 0 0 ---- r) c) ----- 0 0 ---- 0 0 a 0 0 0 I I I -~ '-------"\ y____. --~ I~ ~-~ -, -" C HA K A C f' A ~1tJ A P R (,J E C T OPERATION STUDY I-III, Ill; C r, BE C I, TEL CIVIL&f'INERALS INC.,SFo PRCJECT 14fl79001 ALIISKA POIJEP ~UTIIOR I TY DATE 110581 PAGE 11 ALTEPNATIVE A MCARTI'UR SHORT TUNNELt IUO FI<;I-RELEASES E'IEflGY IN H/1 1 YEAR JfN rEP f'AR APR ~AY JUN JUL AUG SFP OCT NOV DEC TOTYR CALYR 1 17El5f0 1~7'H:? l"d38El 131478 124216 1Hlf52. 11f'.303o 12lf216. 131 1178 155270. 172800. 19'1087. 1756299. 1960 (' 178~(0 1"i2'1}5o 1"1'~88 13147Ho 124216 11£,452. 111'3°3. 124216 131'178. 155270. 172800. 194087. 1750852. 1961 3 178<"1'.0 1"2!JI!': 15138(\ 131478. 1 24216 116'152 11£'39'1. 124216. 131478. 155270. 172800. 19'1087 1750852. 1962 4 178"1'>0. 15?515. 15138R 131478. 12421£.. 116452. 1183q3 124216. 131478. 155270o-172800. 194087· 1750852. 1963 5 178%0 1"i79f'2. 15131'8 131478. 124216 11(:45(1 118393. 1?4216 131478 1!:5270. 172800. 194087. 1756299 1964 6 178'160 152~15. 1513fl8. 131478. 124216. 116452. 1H'393o 124216. 131478. 155270. 172800. 154087. 1750852. 1965 7 17A560 152 .. 15 1513BB 131478. 12'1216. 116452 11!'3°3 124216 131478. 155270. 172800. 194087. 1750852. 1966 8 17P560. 152"15. 1"13P8 131478. 12'1?16 116452. 11£1393. 124216. 131478. 155270. 172800. 194087. 1750852. 1967 9 178~60 157°f0(' 15138£1. 1'11478 12'1216 116452. 1lf393o 124216. 131478. 155270. 172800. 194087. 175629°. 1968 10 17P560 152"15. 1"1380 1~1478. 124216. 116452. 118393o 124216. 131478._ 155270.-172800. _19" 0 8 7. 1750852. 1%9 11 1785(:0 1"2"i15. 1513B8 131478 124216 11f:452. 1183<l3o 124216. 131'178. 1!:5270. 172800o 194087. 1750852. 1970 "'EAN 178~(0. l':i4CCOo 151388. 13147e 124216. 116452. 118'193. 12'1216. 131478. 155270. 172800. 194087. 1752338. flAX 178"f-0 15791:;> 1"'13fl8 1314 78 124216 116'152 118393. 12'1216. 131478. 1:5270. 172800. 194087. 1756299. I'll\. 178560 152515 151388. 1314 78. 124216 -116452.. 11e393e 124216. 131'178. 155270._172800. 19'1087. 1750852. 0 0 l..) I \ 0 u• 0 CIIIIKACI AMNII PROJECT OPERA liON STUDY 1/ H ,I• & C F • BE C liTE L CIVIL&I'I,_ERALS INC.,sF. PROJECT 14! 7'3~01 ALASKA POIJER AUTIIORITY DATE 110581 PAGE 12 AL TEP•JATI VE A ~1C Afl TIIUR SHORT TUNNEL, W/0 FISI-RELEASES REI'AINII\Ci "PILLS I 1\ CI-S -------- YfAR J~N FEr I'AR APR MAY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR 1 0. 0 • 0. 0. 0. o. o. 3170. o. o. o. o. 264. 1960 2 0. 0 o. o. o. o. o. o. 38. o. o. o. 3. 1961 3 c 0. 0 0 0 0. 0. o. o. o. o. 0. o. 1962 ) 4 o. 0. o. !). 0. 0. o. 0. -Oo --0. o. 0. o. 1963 ') c c 0 0 0 0 0. o. o. o. o. o. 0. 1964 6 o. 0. o. o. o. o. o. o. 108. 0 o. o. 9. 1965 7 0 o. 0 0. o. o. 0. (I • o. o. o. o. o. 1966 p 0 0. 0 0. o. 0. 0. 661q. 4 o. Oo o. 552. 1967 9 0 0 0 0. () 0. o. 1 011. o. o. o. o. 84 1968 1 0 0 0 0 0 o. o. 0 0. o. o. ____ o.--0. o. 0 196<1 11 (1. 0 0. (' 0 0 0. 0. o. o. o. o. 0 1970 0 MEAN G 0 r Q Q 0 0. 982. 14. o. o. o. 83. I' AX n c (' 0 o. 6619. 108. o. o. o. 552. MIN 0 0. o. o. L • 0 0 0 o. o. _o. -_o.-o. o. 0 0 0 0 0 ''-/<. _j l ___ j , .. CflAI<f 0'~ I'N A PROJECT OPERATlOrJ STUDY 1/H,H&CFoB[CbTEL ClVlLU'lNERALS INCo~SFo PRCJfCT 141l7"C01 ALASKA POIIER AUTHORITY DATE 110581 PAGE 13 flTERNATIVE A I'CARTI'UP SHORT TUNNELt W/0 FISI-RELEASES AVER fiG[ f [ N E 'l A 1 ]( '• Jr, r I. Dl R IrJ G '>f-ILLS YEAR JfN fffl ~IAfl APR IHY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYfl 1 0 o. 0 r. 0 256. 400. 188. o. o. 0. 70. 1960 ? 0. 0 0 G ~ " . 0 0 327o 400. o. o. o. 61 1961 "" 0 a 0 0 (, . o. o. 2'i3o 358. o. o. o. 51 1962 4 ~ (, 0 n 0. --0 0 c. 0 .. --336. 0 ·--Oo o. 28. 1963 v. uo 5 0 0 o. 0. 0 0. o. 229. 275 o. o. o. lf2o 196'1 6 0. () . 0. o. 0. o. o. o. 400. o. 0. o. 33 1965 7 0 0. 0 0. 0 o. 0 o. 306. 0. o. o. 25 1966 fl 0 0 o. o. o. o. o. 400. 400. o. o. 0. 67o 1967 9 c 0 o. 0. 0. o. o. 400. o. o. o. o. 33 1968 1 0 0 0 o. o .. 0.-o. o. o. o. _o.--o. o. 0 1969 11 0 Q .. 0. 0 0. 0. 0. 0. 0. o. o. 0. o. 1970 1). "EAN 0 0. 0 0. 0 0. 23. 183. 2tt2. o. o. o. 37o I' {IX 0 c 0 0 0 0 2'i6o 400 400. o. o. o. 70. I' IN 0 0 0 o. c 0. o. o. o. _.Q._ _o. -o. 0 f), 0 l) I 1.) Jl 0 '' CI'~KACI AM~ A PRC'JECT OPERATION STUOY I-JII9hE.CF oBECHTEL C IV 1 L&.r-' I NER ALS INCooSF PROJECT 14P7CfiQJ ALAS VA POWER AUTHORITY DATE 110581 PAGE 14 ALTERNATIVE A MCARTIIUR S 1~0 R T TUNNEL, W/0 FISt-RELEASES SLRPLUS EtERGY II\ ,..Ill- -------~ ------ YEAR JAN FE I' MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTYR CAL YR 1 0 0 o. 0 o. o. 72279. 17338lf. lf167. D. o. D. 249830. 196D 2 0 G • 0. D. D. Do Do 118747. 156522. Do o. D. 275269. Jl961 3 0 o. o. 0. o. o. o. 6lf330. 126489. o. Do o. 190819. 1962 4 0. o. o. o. o. o. -Oo ---Do 11D265. D.---0. D. 11 D265. 1963 ') 0 0. D. 0. 0 o. D. 46308. 66163. o. Do 0. 112lf71o 196lf 6 0 0. 0 0. 0. o. o. 0 156522. o. o. o. 156522. 1965 7 c 0 o. o. 0. o. o. o. 88832. o. o. Do 88832. 1966 A 0 0 c. o. 0 o. o. 173384. 156522. o. o. o. 3299D6. 1967 c 0 • p 0. 0 r o. 0. 173"'84. o. o. o. o. 17338lfo 1968 0 1 0 0 0 0 o. 0 o. o. o. o. -D·--De-D. 0 1969 11 0 0 0 0 0 D 0. o. D o. o. o. 0 1970 f'EIIN 0 " 0 0. r D. f.571o 68140. 711680. o. o. o. 153391. ~AX 0 0 0 0 0 0. n219 17338lfo 156522. o. o. o. 329906. ~IN 0 0 ::. o. c. 0 0 o. D. o. o. _D. D. o. ') t) 0 0 0 0 I _ __j L INSTALLfn CAF'~CilY .P:~OO '<I' AN~UAL FLINT FAClf~ OVERLOAC FACTC'R PLANT EFFICIE'CY fl5C FRICTIC~ LOSS CCfFFICIE~T 000002370 "'ONTHLY L(lAO FACTORS 7CC 640 .620 .610 I~ITIAL LAKE STCRACE lf033200o AC-FT t I~IMU~ LAKE STCRAGf Oo AC-FT ~AXI~U~ LAKf STfRAGE 40~3200. AC-fT C--J :_-_j C'H~"CI-!Hfl PROJFCT OPERATION STU[JY I /1 ol qr,rECI!TEL CIVIL&MINE~ALS HC oSF fl~SIIIr PC'I'f~ /UTPORITY 1-..-----I ~ DATE 110581 tLTEf'rAlTVf P r'CARTI'UR SHORT TUI\NELt WITH FISt-RfLEASES 64 0 HO .800 920 1.000 ~-\ ,- I ~---J ~---r \ I) PAGE 1 '1 0 ') f) ') f) ~ {) ) t) ') o () 0 r ') g a 0 0 0 PROJECT 141179)01 RTSERVOIR 'iTORAGE-ELEVAliO~-AREA AC-Fl FFEl AfRf o. 760 o. 202!'!. 7Pio Ill 0 • 7300. 770e 1300. 27200 7ACo 2b90. 111COr. fl :J 0 5670. 2lf1QOr. l ? G 7320. 397000 ,•q r IJ27C 57:'"00 P60o 0 280 76rco~. r 1\(' lOlfCC. 9fi'COa "nO 11 "1°0 1::'24000 c.?c 119f0 llfPnoo r4 r 1232" 17170CO " ( 0 t::>r"( 15730(!0 0(1(1 1?'180 ::'<'"'HCO 1~'JO 13?11(.. 25(14000 182( 13520 2771'-000 1 r 4 0 13740. 3053000. 1"60. l"'\%0. 3335(00. lull G. llfl70 3f2L000o 1 1 0 0. 1 11390. 3C1')Q(lQo 1120. 14'>:>0. 4 P33?CC 11 ;>[ 1521::> TAILIJATEP-rLO! PFLATJrr--St-JP FFET CF<; 210 0 210. 100000 MONTHLY I' If II11H1 I~>;STREAI' FLOWS IN CF S 3(,'j 365 3f5 J(ICij 1091f 1Q01j 1CCJ4 MONTIILY DIVERSJO~ RfQU IR EMEt TS IN CF'i 0 0 G 0 0 0 0 f-'ONTIILY RESER\Olfl fVAPCRAl ION IN INCitES o. Q 0 c 0 0 0 CHAKACHAMNA PROJfCT OPERATION STUDY I' /ll,ll&CF, DECIHEL ri VI l&l" I NE RALS HIC & t 'iF e ALASKA POIJER AUT II OR ITY DATE 110581 ALTERNATIVE B MCARTIIUR SHORT TUNNELt WITH FISI-RELEASES 1 oc If 1094 0 c 0. 0 .. f5 365 0 0 o. o. 365 • 0 0 ~~~ 1 I "' PAGE 2 ') f) ~ I) f) I) ") f) ') () ') ·) ·) ,) ) ._) .J 0 0 0 --~ I Cl!f Kt.U At-INA PROJECT PPfRATION STUDY I') 1-/Hot19Cfof3ECiiTEL CIVIL&f'INERALS Ir-.c •• sF. PROJECT 1487"1 01 ALASKA PO~ER AUTHORITY DATE 110581 PAGE 3 ALTONA Tl VE El MCARH'UR SHORT TUNNELt WITH FISI-RELEASES INFLOWS Til TIE LIIKE I 1\ CFS YEAR JAN f[[l ~AR 1\PR ~AY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR 1 4no. '107 n1 393 "~637 6837 112C9o 9337. 31'15 1439. 799. 870. 3220. 1960 ? P77 ~119 470. 346. lffl 7°83. 12808. 10899. 6?25. 1586o 843. 696. 3767. 1961 3 fd 3 'i41 4 71 470 12 f ~ 0 702'). 13149. 10'111 5'ilf2 1197. 863. 613 3590. 1962 lj 4' El. ~~7e 315 337 lBCl 4735. 13240 0 12208. 5847. 2056. -930. 710. 3587 1963 'j 3(.4 4"'5 33? 477 lf-"'0 C093 lr700. 11798. 4246. 1245. 909. 662. 3'124. 1964 6 419 219. 337. 398. 1286 3490 1304(:. 10516. 10802. 211'1. 597. 466. 3641. 1965 7 ~' e 13c;. 350. 410 1893 P072. 1(:!03. 997lfo 660Bo 1953. 910. 313. 3'159. 1966 B 5"'1 4lf5 38'1 880 2 03 r 8761. 14931. 15695. 6191. 20lf0o 1215. 57lo 4'173. 1967 9 53'1 .-1 D. 4&7. 630 2CJ96 7808. 1">117. 11257. 2793. 976. 689. 612. 3532. 1968 1 0 4h'i 4Ff 500. 652. }ClfBo 9271. 12510. -7297. 2793. 3057. -1215o 5H. 3396. 196<; 11 4'-7 "04 550 f.CCJ 22F>5. f78<J. H360o 7986. 2734 1359. H2o lf60. 2929o 1970 f)' I'EAN 511. 430. 40'1. 536 z on 7251 12307. 10671. 5175o 1729o 883. 592. 3547. flAX A77 "'fl9 550. 899. '?,f:17 '3271. 14931. 1569'). 10802. 3057. 1215. 870. 4473. f'IN 364. ?19. 267. 337o 1265. 3it90. 1030.3. 7297 0 273ito _976. 597. -313. 2929. i) i) () i) 0 0 0 Cf'AKACI Atlt'A PF rJECT OPERATION STUDY ~ 1/fJ,I ~cr.fCCIHFL C1Vll&'-1JI\[R4L') INC.oSF. PRCJECT 1 IJ ll7G ( (11 nAS~A PC'PE.R AUTf!ORITY DATE 110581 PAGE (9 Ill TERt•ATIVE f' tH. A flli.UR SHORT TUNNEL, IJ!Th Fist-RELEASES POIJlfl RELEASE p, (Fr il) YEAR J~N FEP r'AR JIPR ~.A y JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR f} 1 31 c 11 ;>ace. 2739. 2448. 223?. 2160. 2075. 2130. 2335 2682. 3180. 3475. 26~0. 1960 2 32(0 .3151 • 2'l0q • 2'i73. 2 ~4 5. 2?69. 2125. 2130. 2335. 2682. 3180. 3475. 2694. 1961 ') 3 32f·O 3151 2809. 2573 234'i 2269 2125. 2180. 2335. 2682. 3180. 3475. 2699. 1962 4 32f0o ~151. 2809. 2r73o 2"'45. ;>269. --2177. -2180 .,_ -2335. -2682,._ 3180. -34 75. 2703. 1963 'i 3?1i 0 3151. 2809 ?573. 234 5. 2269. 2177. 2180. 2335. 2682. 3180. 34 75. 2703. 1964 ~ 6 "'2(,0. 3151. 2809. 257~. 234'i 2328. 2231o 2232 0 2336. 2682. 3180. 3475. 2717. 1965 7 32l0 .S151 2809 2573. 23lf5o 2269. 2177. 2180. 2335. 2682o 3180. 3475 • 2703. 1966 8 3;uo. ~151 2809. 2573. 2345. 2269. 212.:;. 2130. 2335. 2682. 3180. 3475. 2694. 1967 () Q 321:0. ~(172. 2809. 2573. 2345. 2213. 2125. 2130. 23~5. 2682. 3180o 3564. 2691 1968 \ -10 32(0 3151. 2 BB 1. -2573. 2406 .. ----2269.-2125. -2180 .. -2390. -2H6._ 311!0. -3564. 2727. 196Q 11 3260 31"1. 2881. 257~. 2345. 226Q. 2177. 2232. 2390. 2813. 3260o 3658. 2751. 1970 I) MFAN 3246 3130. 2e15 2562. 234 0. 2260. 214q 2171. 2345. 2699. 3187o 3508. 2701 to' AX 32(0 31!:1 ?881. 2573. 21Jr6 2328 2231 2232. 2390. 2813. 3260. 3658. 2751. f) r'JN 31C4 -'.'JCf;o 2739. 2448. 2232. -2160. -2075. -2130. -2335. -2682.._ :nsa. 3lf75. 2630. ') ') I) t) •) 0 0 0 _.) .._1 J 0 I -__I I _ __) - I ' I - ClfAKAChAMNA PRC'JECT OPERATION STUDY f' llio I' & C F • B E C h T E L CIVIL&MINERALS INCotSF. PRCJECT 14fl7'lC01 ~LASKA POIJER AUTHORITY DATE 110581 PAGE 5 AL TfRIJA T I VE ll ~'CARTIIUR SHORT TUNNEL 9 WITH FISt-RELEASES SPILL I 1\ crs ---~--------- YEAR JAN F [f t'AR APR MAY JUN JUL AUG SFP OCT NOV DEC AVEYR CALYR 1 0 0. 0 0. o. o. 8~6o 6113o 0. o. o. o. 579 1960 2 0 o. o. Oo o. o. o. 2082o 2796. 0. o. 0. 406. 1961 3 0 0. 0 o. 0. o. 0. 1218 2113 o. Oo o. 278. 1962 4 o. c. a c. Oo o. o. -0 0 2065. 0. o. 0. 172. 1963 5 c 0 o. 0 (). o. 0. 831. 817. 0. o. o. 137. 1964 f, 0 u. 0. a. 0 a o o. 0 0 3180. 0. o. o. 265. 1965 7 0 0. 0 Oo o. 0. o. o. 1321. o. o. 0. 110. 1966 8 0 0 o. o. c. 0 o. 9736. 2762. o. o. o. 1041. 1967 q n • e 0 0. 0 o. 0 4288. o. 0. o. 0. 3'17. 1968 1(1 u. o. o. o. 0. o. c. o. 0 -0. -0. -0. o. 196q 11 0 o. c. 0. c 0 0. o. o. o. o. o. Oo 1970 I'EAN 0 Oo o. o. r • 0. 76. 2206. 1368. o. o. o. 30lfo t'~X e 0 0 0. 0 0. 836. 9736 318 0. o. a. 0. 1041. ~11 N o. 0. o. o. o. 0. o. o. o. 0. --o .. o. o. 1) ' 0 (}I g, 0 ., CllfKACIIM1t-A PROJECT OPERATION STUDY Ct j-./ti~H&rF .nECHTEL C I VILU11NERALS 11\jC •• SF PRCJECT )ljiJ7°001 ALASKA POIJER AUTIIORITY DATE 110581 PAGE 6 ~ /ILTERNATIVE B MCARTIIUR SHORT TUNNELo IIITH FISt-RELEASES FJSII RELEASE JN CFS 0 YEAR JAN Hr "AR APR MAY JUN JUL AUG SEP OCT NOV DEC AVEYR CAL YR 0 1 365 "'>07. 267 393. 1094. 1091f. 1091f. 1091f. 109lj 365. 365. 365. 658. 1960 2 3Pio 3 f.'i 0 365 31f6. 1 091f. 1094. 1091f. 1094. 1094. 365. 365. 365. 667 1961 .., 3(5 • .3(5. 365 • lt70. 1091t. 1091t. 109'1. 1091fo 1091fo 365. 365o 365. 677 1962 I) 4 ..,f,5. -.,o:: 7. -315.--337 .. --1 094., --l 094 .. ---1094 ·---1094 ·----1 091f ... 365<>--365e ---365. 662. 1963 5 3(,1f 3l:5& 332 t,77 1094 .. 1094. 1C94o 109'1. 11!9'1 365. 365. 365. 675. 1964 f, 3,:.5 219 337o 3GB. 1094. 1091t. 109'1. 1094. 1094. 365. 365o 365. 657 1965 f) 7 3t;5 3~£ 350 It 1 0. 1C9'1o 1094. 1094. 109'1o 1094. 365. 365. 313. 664. 1966 fl 3f.5. 365 365. PBO. 1C94. 109'1. 1091to 109'1. 109'1. 365. 365. 365. 712. 1967 0 3( !J. ~65. 36"io 630. 1 09'1. 1094. 109'1. 1091t. 1094. 365. 365. 365. £91. 1968 f) ] 0 ..,,5. -.,f. 5o 365. 65;:> .. -1094.---1094. 1094o-1 09 4 ·--1094. -~65o-365.-365. 693. 1969 11 365. 36~. 365. 899. 100lj 1094. 109'1. 1094. 1094. 3{>5. 365. 365. 713 1970 0 MEAN 365. 3lj3. 31f5. 5~6. 1094. 1094. 109'1. 1094. l091f. 365. 365. 360. 679. "AX ..,1"5 365 • 36"i. 899 1 O'lt, 1094 109'1. 1094. 10911. 365. 365. 365. 713. f) MIN 361t ;:>1". 267. 3!7. 1 O':l4 • 109'1. 10°4. 1 0 9 4. 1094. -365 .. 365 ... 313. 657. f) I) 0 () ,) 1..) 0 0 ~ _) J ,_ ,0 L __ _ I I (_ NfT EVAFOPATI~~ I~ AC-FT YEAR .J ,, rJ FEP 0. G 2 r c 3 0 l lj 0 c • 5 0 ( 6 0. o. 7 0 n 8 0 0 q (' 0 10 0 Oo 11 0 0 fo'EAN 0 () ~lAX 0 0 HI'IJ 0 0. MfR t.PR 0 0. o. o. 0 o. 0 0. e 0. 0. o. o. 0. 0. o. o. o. o. -0. 0. 0. 0 0. 0. 0. o. o. r -- ( l CHHAC'f Ar NA PRflJECT OPERATION STUDY Ill oi 1FCFoBEChTEL CIVILH'I"JERALS INCotSF. AL~S~A PO~ER AUTHf1RJTY DATE 110581 ALTEkNATJVE B MCARTfUR SHORT TUNNEL, YJTH FIS~ RELEASES MAY JUN JUL AUG SEP OCT NOV 0. 0. o. 0 o. o. o. 0 o. o. o. 0 o. 0. 0 0. 0 o. o. o. Oo o. o. o. _o. -o. o.-o. (' 0 0 o. 0. o. o. o. 0 0 a. o. o. 0. 0. o. 0. 0. o. o. o. o. o. o. o. 0 o. o. o. 0 0. o. o. o. o. c. -Oo --0. -__ Q. -o. _o._ -o. __ - 0. o. 0 0 o. o. o. 0. o. o. o. o. 0. o. o. 0. o. o. o. o. o. o. -o. o. o. o. -Oa--0 0 ---, PAGE 7 DEC AVEYR CALYR 0, 0 0. 1960 o. 0 1961 o. I 0 o 1962 0. o. 1963 0 0 1964 o. 0 196'1 o. o. 1966 o. 0. 1967 Oo o. 1968 o. 0 1969 0. o. 1°70 0. o. o. 0. 0. 0 r) ' 0 () 0 0 0, 0 ' C~~KACtAMI\A PROJECT OPfRA liON STUDY ~II tllf.CF,BECI1TEL CIVILUIJNERAL'i JNC.,SF. PROJErT 14879001 ALASKA P0~1 ER AUTHORITY DATE 110581 PAGE 8 ALTERNATIVE B fo1CARTIIUR SHORT TUNNELt IJ I Tli FISt-RELEASES E 0 P. ST'lRAt;[ I I ACRE-fl YEA,R JAN rrr MAR APR r-'H JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR ] 3f4441l6. 36720!:1 ~50~609. 3357932. 3n705'+. ~59C235. 4033200 4033200. 4016273. 3c17430o 3754049. 3571403. 3722577. 1960 2 34024~7. ~239H5o 3073650. 2920553. 2824773. 3099f.75. 3689300. 4033200. 4033200. 39113396. 3782633. 3589288. 3116'l~32. 1%1 3 34n531q 324CH1. 3073928. 2920830. 2787174. ~058625. 366°218. 4033200. 4033200. 3919477. 3759904. 3561'156o 3455203 1962 If 33£9186. 31941C~• 3021502. 2El68398. 2767700. 2849328. 3462870o-4012209o-4033200o 3'372295. 3816709._3624225. 3415984. 1963 5 3'•~37°7. 32'16581 3073891. 292G7c3o 2821878. 3103326. 3560138. 4033200 4033200. 3c22428o 3765593. 3570158. 3456249 1964 6 3~7"i0~0 ~1980~7 3025346. 21172242. 2739877. 27'+3929. 3341621. 3783716. 4033200. 3975861. 3800460. 3592974. 3373358 1965 7 3.393C40o 3 211• '3 If 7. 3046256. 2803152. 27911110. 307f308o 3510710. 3'322686. 11033200. 3965961. 3809186. 3595489. 3438829. 1966 8 34C524 7 3t'3'1c;::a. 3063397. 2910300. 282"i682. 3144879. 3865042. 4033200. '1033200. 3'371311. 3832684o 3631653. 31195793 196 7 9 344lf.17. 3273230. 310681 o.. 2953713. 2°26'192. 3194307. 3802931. 4033200. 3995328. 3868016. 3698073. 349H18o 3482320. 1968 10 33 1il0'19. 3132759. 2963905. 2810801. 271539ll. 3066'338. :'163(>240. 31!85616. 3844'173. 38'11176. 3702533. 3li94213. 3366425. 196° 11 3301flA1o ~134~"1. 296881 1o 2815707. 27435'19. 29li71100. 3383303. 3669834 3625181. 35133111· 3341792. 3122697. 32lli007. 1970 I'E AN 34 23817 325320fl. 30£13737. 2931311. 2P477'lO. 3079723. 3632416. 395211'1. 3973968 38C1881o 3733056. 3531607 3444552 flAY .. f14lj lj fl6 3f.720!:1 3503609. 3357q32. 3~7705'1 ~59C235. '1033200. 4C33200. 11033200. 3975861. 383268lio 3631653. 372~577 I'll'. 330]04'J. 3132759. 296390'). 2810801. 2715-.'lllo ~743929. 3341621o 366983'1. 3625181. 351334lo-33li1792o 3122697. 32111007. ) 0 .. ~ ~--!' ' ) \ -_) --! -----, r Cl'~~ ACI Afl~ A PROJECT C'PERATION STUDY ') I /II , II "' C f • E. E C 1'1 E L CIVILKI'INERALS If>.C eSF. FRCJECT 14b7'>',rl Ill .ASK A POI.[R f.UTIIOR I TV DATE. 110581 PAGE P) tLTfPI\1\TIVE p ~CARTI'UR SHORT TUNI\Elv Willi FISt-RELEASES WATER E'.ALAI\!CI ') YEAR JI\N FEP f'AR APR 11A Y Jlll\! JUL AUG SEP OCT NOV DEC AVEYR CALYR ') 0 0 0 0 • r o. o. 0. o. o. o. o. o. 1%0 2 c r 0 0 0 Q 0 o. o. o. o. o. 0. 0 1961 3 0 0 Q 0 0 o. o. Oo 0. o. o. 0. 0. 1%2 0 4 0 0 0 0. 0 o. o. o. Oo o.-o. o. o. 1963 5 0 ~ 0 c. 0. 0. o. Oo 0. Oo o. 0 0 1964 . f. 0 0 0. 0. 0 o. o. 0. o. o. o. o. o. 1965 f) 7 0 (l o. 0 0 0. 0. 0 o. 0. o. 0 o. 1966 !1 0 0. 0 o. 0 0 o. o. o. o. 0. o. 0. 1967 q 0 0 0. 0. 0. 0. 0 o. o. o. o. o. Q 1968 I') 1 0 o. o. o. o. o. o. o. o. o. D • -o. o. o. 1%9 11 0 c c 0. 0 0 o. Do o. o. Oo o. 0 0 1970 f) PEMI 0 0 0 0 • 0 0 o. 0. 0. o. o. o. 0 f'AX 0 n a 0 0 0 0. 0 o. 0. o. o. o. f) MIN o. 0. o. o. 0 o. o. o. o. o. -0. 0. o. f) 0 !) () i) <) 0 0 0 QJ 0 0 ., C II f K A C I' AM ~1 11 PROJECT OPERATION STUDY 1/Holi&CFoRErHTEL CJVIL&MJNERALS lNCooSFo PflrJECT ]4A7"c01 ALASKA PnlJER AUTf10R ITY DATE 11 0 581 PAGE 10 /ILTEPNATIVE !l ~CARTIIUR S II OR T TUNt.EL~ 1/JTI' FISt-RELEASES POlJfP lfl I lJ YEA f.' J~N Fff1 fJAR APR MAY JUN JUL AUG SfP OCT NOV DEC AVEYR CALYR 1 1"1' H7 11'>1\o 151. 138 133 1 31 0 13!1 0 151. 172. 198o 215. 165. 1960 ;> 1 ( p 11' 7. 1' q. 1 'i 1 • 1~8. 133 131. 138 151. 172. 198. 215 165. 1961 ... 1"P l p 7. 168 151. 1.31' 133 131 138. 151. 172. 198 • 215. 165 196;> 4 lrO un 1Mf!o 151. 1~R. 13 .... 131. -138 ·-151. ---172._ 198.---215. 165. 1963 5 1Cfl , e 1. Hllo 151. 131'. 133 131. 138. 151. 172. 198. 215. 165. 1961f ,., 1r11 IE7 161'. 151. nP 133 131. 138. 151 172. 198. 215. 165. 1965 7 108 1P7 lfll 151 13ll 133 131. 138 151. 172. 198. 215. 165. 1%6 il 1°8 1 fl7. 160. 1 'i 1 • 1 ... , •• 133. 131. 138. 151. 172. 198. 215. 165. 1967 a 1a£1. 1 p 7 16A 151 1 7 p 133 131 138 151 172. 198. 215. 165. 1968 1 0 108 1 p 7. 160. 1"1. 17 p. 133. 131. 138. 151. 172. 1.98. ---215. 165. 1969 11 1' p 1E7 16R 1"o1 1'f: 133 1'H 138. 151. 172. 198. 215. 165. 1970 I'EAN 1 r 8 o 1P7 168 1 "'1 1 ~ ll 133. 131 138 151. 172o 198. 215. 165. fJA)C 1<'8 H'7 1f.E' 151. 138 133 131 138. 151 172. 198. 215. 165. nN 1"(! lf7. lf.llo 151. L31l. 13 .... 131. 138. 151. 172. 198o 215 165 0 0 0 PROJECT 14879G01 ENERGY II\ I'WII J ~ ( ___ \ CIIAKACI'AMNA PROJECT OPERATION STUDY 1/Htti&CFoBECHTfl CIVIL&I'INERALS INCooSFo ALASKA POWER AUT~PRITY DATE 1105A1 ALTERNATIVE P MCARTIJUP SHORT TUNNEL, WITH FISt-RELEASES PAGE 11 HAR JllN ff[ APR l'fY JUN JUL AUG SEP OCT NOV DEC TOTYR CALYR 1 2 3 4 5 6 7 8 9 1 0 11 "'EAN I' AX I' IN 14 1"' 12 147312 14n 12 147312 147312 147312 l'l7.312. 147312 147312 147312. 147312 1'17312 130~18 12"f;:5. 1?"-u:r 1?5(2~. 130311' 125£2!: 12~12"· 1251-2~. 130""18. 125f~5. 1?51<2 ... 127050 124895. 1?'1P9'io 124895. 1?4895 124895. 12'1895. 124895. 1('4f95. 124895 12489'io 12489" 108470. 10e470. 1Ci8470o 108470. 108470o 108470. 10P'l70o 101'470. 108470. 108470. 1(1!''170. 102478 102478. 102478. 102478. 102478. 102478. 102478. 102478. 102478 102478. 102478. 124895. 108470. 102478. 147312. 13G~1Po 124P95o 10P470o 102478 • 147312o 1?'il25o 124895o 108470o 102478. 96073 976711 96073. 97674. 9607~ 97674. 96073. -97674·- 96()73. 97674. 96073. 97674. %~73. 97674. 96073. 97674. 96073o 97674 '36073. -9767'1. 96073. 97674. 102478. 102478. 102478. 102'178. 102478. 102478. 102478. 102478. 1 02'178. 102478o 102478. 108470. 108470. 108470. 108'170o 108'170. 108470. 108470. 108'170. 108'170. 108470. 108470. 128097. 142560. 160122. 14489'17. 128097. 142560. 1~0122. 1444453. 128097. 1'12560. 160122. 14'14453. 128097o-142560c 1E:0122o 1444453o 128097. 142560. 160122. 1'1489'17. 128097. 142560. 160122. 1'144453. 128097. 142560. 160122. 14'14453. 128097. 142560. 160122. 1444453. 128097. 142560. 160122. 1448947. 128097o-142560e-lf0122o 144'1453. 128097. 1'12560. 160122. 1444453. 96073. 97674. 102478. 108470. 128097. 142560. 160122. 1445679. 96073o 97674o 102478o 108470o 128097o 142560o 160122o 1448947o .96073. _97674. 102478. 108470. 128097. _142560 .... _160122. 144'1453. 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 }Q70 ~ ----- 0 0 I) 0 I} ') J J I) r) 1) ,) .) l) 0 0• 0 0 0 a 0 C.HAI<AC11A~.NA PRf'JfCT GPERA Tl ON STUDY t-/II , 11 F.t F • B F C Ill E L CIVIL&MINFRALS INCooSF. PPCJECT 14~79001 ALASKA POIIER AUTIIORITY DATE 110581 PAGE 12 ALTERNATIVE E' I'CARTIUR SHORT TUNNELo IIITH FISt-RELEASES REIIAINII\G SPILL'> I 1\ CFS YF~R JAN FEP 1-'AR APR MAY JUN JUL AUG SEP OCT NOV DEC AVEYR CALYR 1 0 c 0 D o. c. 0. o. 3189. 0. o. 0. o. 266. ,196 0 2 0 0 o. D o. o. o. o .. 66o 0. o. o. 5o 1961 3 0 0. o. o. 0. 0. o. o. o. o. 0. o. Do 1962 4 0. c. o. o. c. o. ----Do---Q,._ o .. Q., __ -0 e -,o. o. 1963 ., 0 0 0 0. 0 0 • 0. o. o. o. o. o. o. 1961+ 6 0. o. o. o. o. Do o. o. 1+45. o. o. 0. 37 1965 7 0 0. o. o. 0. o. o. o. 0. o. o. o. o. 1966 ll 0. 0 o. o. 0 0 o. o. 6812· 32. o. o. o. 570. 1967 q 0. 0. o. 0. 0. 0. o. 1364. o. o. Do o. 114. 1968 0 10 0 o. o. 0. -o. o. o. -0 .. o. D •--De o. o. 1969 11 D 0 o. 0. 0 0 0 o. Co o. o. 0. o. 1970 MEAIIJ 0. o. 0. 0. 0 0. o. 1033. If 9. o. o. 0 qo MAX (). o. o. 0 0. o. o. 6812. lflf5o o. o. o. 570 MIN o. 0 o. o. o. o.--0. --o. 0. _o.-_o. ---o. o. 0 0 0 0 ---r~-:J .. .. r -~ ... ,-----, _! I -~ ) L -----:J -=--= CHAKACHAMI\A PROJECT OPERATION STUDY 1-/H 91i&CF o BECJ· TEL C IV I L&M I NERALS _Jt-.C o, SF • PRCJECT 14!79001 ALASKA POIJEP AUTHORITY ALTfRNATIVE n r-"CARTHUR SHORT TUNNEL, WITH FISt- AVERAGE GENERAl If I\ II\ l"lol DLRING '>PILLS YEAR JMJ rEI:' I"AR HR i"AY JUN JUL AUG SEP 1 0 c. o. o. o. o. 190. 330. o. 2 0 0 0 o. o. o. o. 275. 330. 3 0 0 o. o. o. 0 0 o. 222e 29Co 4 c. o. :l. o. o. o. o. o. 287. "i 0 0 o. o. 0. o. o. 196. 205. 6 0. 0 c. o. o. 0. 0 0 o. 330. 7 0 0 o. 0 u. o. 0 o. 238. !' o. o. o. 0. Go 0. 0 330. 330. Q c 0 0 o. o. l'. 0 0 o. 330. o. 10 0 0 o. o. 0 o. 0 o._ -0. 11 0 0. o. o. 0 0 o. o. o. r-'EAN 0 0 0 0 0 0 0 o. 17. 153. 183. f'AX 0 0 0 o. o. 0 0. 190. 330. 330. MIN o. 0 o. o. o. o. o. o. Do ~-"" ,~ I===-"\ I I '--c~ DATE 110581 RELEASES OCT NOV DEC o. o. 0 o. 0 0 0 0 o. o. o. 0 0-_o. -c. o. o. o. Do Do o. o. o. o. o. o. o. o. o. o. o. ___ _o. o. o. o. o. o. o. o. o. o. o. o. _o. o. I ... PAGE AVEYR 43. 50. 43. 24o 33. 27o 20. 55. 27o o. o. 29. 55. o. --c_ 13 CALYR 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 - (') 0· 0' t) 0 i) I 0' Q, 0 01 I o' l ol I o' CHAI"ACI"Afi'\A PROJfCT OPERATION STUDY ~ h/lloii&CF.llECHTEl CIVIL&HINfRAlS INCooSFo PRCJECT 14870'101 Alii'SKI\ POlJER I'UTHORJTY DATE 110581 PAGE 14 ~ ftlTERN.I>TIVE fl "C/IRTHUR SHORT TUNNELt WITH F I Sl-RELEASES SURPLUS ENfRGY II\ 1-'WII ') Yr AR JAN FEB MAR AFR MAY JUN JUL AUG SEP OCT NOV DEC TOTYR CAlYR "') 0 0. 0. 0. c. 0. '13738o 143042. 0. o. o. o. 186780. 1960 ? 0 c o. 0 o. o. o. 1 021'15. 129130. o. o. o. 231275. 1961 I) 3 n 0 o. o. 0. 0. 0. 62388. 100187. o. o. o. 162575. 1962 4-0 0. ---0. --o. ---Oo----0 c.----IJ-.--9 794 6 ·----0 ., __ _ Q .. ____ - o .. 97946. 1963 'i 0 0. 0 o. 0 o. o. 43608. 39391o 0. o. o. 82999. 196'1 0 6 0 0. o. o. o. o. o. o. 129130. o. o. o. 129130. 196'i 7 0 0. o. o. o. 0. Do o. 63069. o. o. o. 63069. 1966 p c o. o. o. 0. 0. o. 143042. 129130. o. o. o. 272173. 1967 t) 9 o. • 0 o. 0. o. o • o. 1'130'12· 0. Oo o. o. 1'130'12. 1968 10 0 o. o. o. 0 ---Do -o. ----Q.,_ -o. -Do----o .. o. o. 1969 11 0. 0. :J. 0 0. 0. o. 0 0 0 o. o. o. o. 1970 0 fEAN 0. 0 o. 0 0 o. 3976. 57933. 62544. o .. o. o. 124'154. "AX o. 0 o. 0. o. o. '13738. 1430'12. 129130. o. o. o. 272173. 0 "IN o. o. o. o. c. o. o. -o. o. _Q._ __Q 0 -o. o. G) \ 0 () 0 •) 0 Q ) I l () ---I -~ -/J ,~(..-"1"'1 ----.. .. ~ I ----~-_) ~ ~ l " - 1--I PROJECT Jql\79001 IN 5 TALL ED CAPACITY 8 J 0 0 0 0 o K 11 A~NUAL PLANT FACTUR 5 OVERLOAD FACTURa 1.00 PLANT ~FFiciENCy! .esn FRICTI!Jtl Lnss CUtFFIClENTx 0000021:100 MONTHLY LOAD FACTURSi .920 ,B7o '780 700 btiO b20 INITIAL LAKE. STORAGE 111033200. AC.,FT HINXMIJM LAKE 'HllRAGE 124?3000 • AC•FT MAXIMUM LAKE STORAGE &11033200, AC~FT biD .,..-. ,----~ ( --,\ ~----I ~ -I !ilttnia ......... lAKJ; .. ~ ~A -,,.,O:CT ~ ATL -_IUD~ 11/H, H&CF 1 BFCHTEL C IVIL&MINERALS INC • 1 SF, ALASKA POWER AUTHORITY DATE 323!1.3 ALTERNATIVE C! CHAKACHATilA TU~lNEl., WITH(JUT FISH RELEASE.S ouo 700 oBOO Pt.GE l ,------- \ ) -~ -.... CHAKACHAMNA PROJECT OPERATION STUDY H/II,H~CF,BECHTEL CIVIL&MINERAL.S INC.,SFe PROJE.CT IIJAHOO I ALASKA POWER AUTHORITY DATE 32383 PAGE 2 ALTERNATIVE C I CHAKACHATNA TUNNEL, WITHOUT FISH RELEASE.S RESERVOIR STORAGE~ELEVATION•AREAi ACoFT FEET ACR~ 0. 7b0, o. 202'5. 7b5. a 1 o. 7300. 770 1300. 27200. 780. 2b90. '-1\louo. BOO '5b70 2/Jiouo. 820. 73?0. 397ooo. 6/JO 8270. 572ooo. 860. 9280. 7b9ooo. aao, 10400. 96Booo. 900 115911 122/Jooo. 920 119bO. 1llb7ooo. '1/JO 12320. 1717ooo. 9b0 12b50 I9Booo. 980 12980. 223oooo. 1 on o. 13280, 25 0 II 0 0 0 0 1020 13520 277onoo. IOIJO 1'\7/JU 30S3ooo. lObO 139b0 3BSooo. 106\l 111170 3o2oooo. II 0 0, 11J390. 3'1101)00. 1120. 111o2o. IJ0332oo. 1128 15212 TAILI'IATER•FLOW RELATIONSHIP! FE.ET CFS IJOO 0 IIIlO tuonoo MONTHLY t11NIMUM IIISTREAH FLOWS IN CFS! '- 0. 0 0 0. 0 0. 0. 0 0. o. 0. o. ..... HUNTHL.Y DIVEH&IUN RECJU I REr~EN T:, IN CFS! ._ 0. n 0 0. 0 0. o. n 0 o. 0. 0. MONTHLY RESERVOIR EVAPORATION HI INCHES! -o. n 0 0. 0 o. o. _ o __ o. __ o. 0 -_o. ~, .!.«! ~ ~ ' ., -~ ---...;;;;;_- ,_ ::c~ (~ ~~"""""') r~, l~:l r~l ~ I~ --J ~ ~-) -.. ,--.,._.----.. L~--~ '-,. --I __ , c~~ 1 ___ ,, ~~ CHAK AC HAMNA PROJECT OPERA T fur~ STUDY H/H,H~CF,BECHTEL CIVIL~MINERALS INC.,SF. PROJECT 14879001 ALASKA POWER AUTHORITY DATE 32363 PAGE 3 ALTERNATIVE Cl CHAKACHATNA TUI~NEL f IH THUUT FISH RELEASES HlFl.OWS TO THE LAKE IN CFS YEAR JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT rwv DEC AVEYR CALYR I tiOO~ 307 267, 393, 3b37 i1837 11209, 9337. 31115. 11139. H9 0 870. 3220. 19b0 2 877 p 589 £170 3Qb. 1881 H83, 12808 10899. 6225. 1586. 8£13. b96. 37b7. !9b1 3 633 541. ll 7 I • 117 0. 1265 7925 13149. 10tlll. 55112. 1197 863. b 13. 3590, 19&2 (j £198~ 357 315 337. 1801 Ll735.-13249. 12208. 58117. 2056. 930. 71 0. 3587, 19&3 5 36tl 435. 332. 1177. 1830 8093 10700. 11798. 1124&, 12115. 909, &62. 31124. 19b£1 6 t119,. 219. 337 398. 1286. 3tl90, J30Q6. 10516. 10802, 21 ill 597. 466, .ib41. 1%5 7 38~, 33& 350. ljl 0. 1893 ao12 10303. 99741 6&oa. 1953. 910. 3 13. 31lS9, 19&6 8 531 /149. 3811. sao. 2n3o 8761 111931. 15695. 6191, 2040, 1215. 571. IIIA73, 19&7 9 5311, Sto. 1167 630. 2996 78081' 13117. 11257. 2793. 976. b89. 612. 35]2. 19&8 1 0 IJ8S QB&. son. b52. 19118 9271 12510 7297. 2793. 3057. 1215. 541. 3396. 19&9 11 IJ97 ~04. 550. 899. 22b5 6789 10360, 7986. 2734. 1359, 742, tlbO. 2929, 1970 MEAN 511 430, 4011, 536. 2076 7C!51 1C!307 10671, 5175. 1729, 8113 1 592. 351J7, MAX 877. 589, 550 89q. 3b37 9271' JQ931. 15695, 10802. 3057 1215. 871). 11£17.5. HlN ]btl 219 2b7, 337. 12b5 31J90' 10303. 7297. 2734. 976. 5q7. ~13. 2929, - - CHAKACHAMNA PROJECT OPEHATION STUDY H/H,HIICF,I:IECitTEL CIVIL~MINE.RALS INC.,SF. PROJECT 14879001 ALA~KA POWER AUTHORITY DATE 32383 PAGE. ALTtRNATIVE Cs CHAKACHATNA TUIJNEL, WITHOUT FISH RELEASES POWER Rt.LEASE IN CFS YEAR JAN F-EB HAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC "VEVR CALVR -1 36B 3~67 326o 2903. 2o36 2550 21129. 21178. 2725. 31116, 3798, 11187, 31 t 3. iQ60 2 3939. 3d28. 33811. 3 11 I • 2821 272bp !?507 21179. 2725, 31116. 3798. 11187, 3221. 19bt 3 3939 3b28, 33811 3111 • 2923 2727 2507. 21179. 2725. 31116. 3798. U!B3, 32,?9 1962 ' ..... ll 3939 38 31. 3508. 3111 • 29211 2825 259(1 25'56. 2725, 311J6. 3798. 11187. 3262. 1963 5 3939, 3828 33diJ. 3111. 28;>1 2727. 2590. 2556. 2725. 3146. 3798. lq87. 32JIJ. !96/J b 3939. 3831, 3'508, 3 111 • 2921J 2825 2680, 2638. 2725. 31116. 3798, 11187, 32'16. 1965 ... .... 7 3939,. 3831. .S5oa. 311 I • 2923 2727, 2590. 25~6. 2725, 31116 "\798. 4187. 3253. 1966 8 3939, 3828. 3381. 3 I II I 2A21 2726,. 2507. 2479. 2725, 31116. 3798. 11187. 3221. 1967 q 3939 3828 3384. 3111. 2821 2726 2507. 2479. 27251 31461 3Boo. 113113. 32311. !968 10 3939~ 3831, 3506. 31 I 1 I 2'12/J ?727p 2507. 25551 2725. 31116 3670. IH87. 32361 t9b9 II 3936 3828 3364. 3111 I 28~1 272b 2507 2556, 2725, !2118. 38 (10 0 113/J31 32Q9. 1970 .... 11EAN 391/J 360b 3tll8 3092. 2851 2728 25:S8 2528. 2725. !1~6. 3787. 11215, 3230. MAX 3939, 3831. 3506 31 II • 29211 2825,. 2b8() 2638. 2725. 32118. "3600, 43/J31 327b. MIN 3673 3~67 32bo, 2903, 263b 2550 2/J29. 21l78, 2725. 3111b 3&70. 11163. 311 31 - .... -l .,.. \ - PROJECT I4R7900l SPILL IN CFS YEAR I 2 3 u 5 b 7 8 q I 0 11 liE AN MA,I( HlN JAN o, o, o, o, o, o, 0 0~ 0 o: 0 0 o' 0 FE!:! 0 0' 0. 0. 0. 0. 0. 0 0 0. o. 0. 0. 0 0. o. 0. o. o. o. o. o. 0 0 o. o. o. o. o. r -__ J APR 0. 0. 0 I 0. 0. 0. 0, I) I o. o. o. 0, o. o. jl CHAKACHAHNA PROJECT OPERATION STUDY HIH,H&CF,I:!ECHTEL CIVIL&MINE:.RALS INC,,SF. ALASKA POWER AUTHORITY -I ~· DATf:. 32383 ALTE:.RNATIVf C& CHAKACHATtiA TUNNEL, WITHOUT FXSH RE:.LE.ASES HAY 0 0 0 0 0 0 0 0 0 o. 0 0 0 0 JUNE 0 o' 0 JULY 2177 o. o. 0. 01 0 o. o. I) 0 0 o. 2177 0. AUG o8S9 .- Bb5, 2292. 221. 18b2. 0. 0. 11212. 51133. 0. o. 2840. 11212, o. SEPT 11201 3Soo. 28171 3122. 15211 1111071 2791. 34ob, oe. 0. 0. 2010. 1!407. o. OCT o. 0, 0 0. 0. 0, 0 0 0. o. 0. 0. 0, o. o. NOV 0. o. 0. 0. o, (). 0. 0. 0. o. o. 0 1 0. o. Of:.C 0. 0 1 0. 0. 0, 0. 0. 0. 0. 0. 01 0. 0. o. PAGE 5 AVEYR CAL VR 788. 572. ll2b 279. 282. 367, 233. 12?3. usa. (l, 0. 1%0 19b1 1962 1963 !9bll 1965 19bb 1967 1968 lqbq 1970 ~-l .... CHAKACiiAHNA PROJECT OPERATION STUDY ..... H/H,H&CF,HFCHTEL CIVIL&HINERALS INC.,:,F. PROJECT 14A7900J ALASKA POWER AUTHORITY DATE 32383 PAGE .... ALTERNATIVE Ci CHAKACHA HIA TU!INEL., WITHOUT FISH RELEASES FISit RELEASE IN CFS YEAR JMI FEB MAR APR HAY JUNE JULY AUG SEPT OCT NOV Df.C AVFYR CALYR o' ..... I o, 0. 0 u. 0 0 o. o. o. 0. 0. 0. 1960 2 (l 0 0 0. 0 0 o. o. o. 0 o. o. 0. 1961 3 01' 0. 0. 0, 0 o,. o. 0. o. 0. o. 0 I 0 0 1962 J 4 o, o. o. o. 0 0 0. o. 0. o. 0 1 0. 0. 1963 s o, 0. o. 0 0 0 op 0. o. o. 0 I 0 1 0. ll. 19611 b 0 0 I) • I) I 0 0 o. o. 0. 0 0 o. o. o. 1965 . "" 7 o, 0. (). o. 0 0 o. 0. 01 0. o. 0. 0. 1966 8 0 0. 0 0 0 0 0 o. Oo o. 0. 0 1 Q I 0 I 1967 9 o, 0 o. o. 0 0 0. o. o. o. 0 1 0. 0 0 1968 > ..... 10 0 0. o. 0. 0 0 o. o. o. o. o. 0. 0. 19&9 11 0 0. 0. 0. 0 0 o. o. 0. o. 0. 0. 0. 1970 . ..... 'lEAN () 0 0 0. o. 0 0 0 o. o. o. o. 0. 0. MAX 0 u. 0 o. 0 0 o. 0. 0. 0. 0 0 0. 0. MIN 0 0. o. o. 0 0 o. o. o. 0. o. 0. 0 I I j-L~= ~~-1 -.. r~~ .. ~\ I' ~--I - L __,__-J L I ~ _j "1, I ' / -J -~}! _., '--___, ~> --~,.,...! -CHAKACHAHNA PROJECT OPERATION STUDY HIH,H&CF,BfCHTFL CIVlL&MINERA~S INC.,SF. PROJECT lllA79UOl ALASKA POWER AUTHORITY DATE 32383 PAGE 7 ALTERNATIVE c! CHAKACHATNA TUNNEL, WITHIJUT f"I SH RELEAS~S ,NET EVAPURATimJ UJ ACaFT YEAR JAN fEU MAR APR HAY JUNE JULY AUG S!:.PT OCT NllV DE.C AVEYR CAL't'R I o, 0 0 o. 0 OP 0 0 0. 0 0 0. o. (j. 0. 19&0 2 o, 0. 0 o. 0 op 0 0. 0 o. 0. 0. 0' IQbl l 0 0. o. 0. 0 0 0 0. 0. f) • 0' 0. 0. 19&2 Q OP 0 0. 0. 0 o, o. o. o. o. 0. 0. 0 0 19&3 5 0 0. o. o. 0 0 0. o. 0. 0. 0. o. 0. 19btl b , 0 o. o. 0 0~ o. o. 0 0 o. 0. o. 0. ll)bS Op 7 o, 0. 0. o. 0 o, o. o. 0. 0. 0. 0. 0. 19&6 8 0 0. o. o. 0 0 0 o. 0. o. o. o. 0. 19&7 9 o, 0. o. o. 0 OP o. o. o. 0. 0. 0. 0. 1%8 10 o, 0. o. o. 0 0 o. o. 0' o. 0 0 0. 0 0 tQ&Q 1 I 0 o. o. o. 0 0 0 Oo 0. 0. 0. 0. 0. 1Q70 tiE AN 0 0. o. 0. 0 0 o. o. 0. 0. 0. 0. 0. MAX o, 0 o. o. 0 o, () 0. a. 0. 0. 0. 0. '"Ill~ 0 0. 0. o. 0 0 o. 0. Oo 0. 0. 0 0 0. - '-CHAKACHAHNA PROJECT OPERATION STUDY HIH.H&CF,BECHTEL CIVIL&MINERALS INC,,SF. PROJEcT ltj87900t ALASKA POWER AUTHORITY DATE:. 32383 PAGE:. 8 ALTERNATIVE C! CHAKACHATNA TUNNEL, WITHOUT FISH RELEASES E,o.P. STORAGE IN ACREoFT YEAR JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVfVR CALYR I 38·q 933 lb1JIHI15. JIJ59987 3liObOb, 3372125 3b27219 IJ033200. IJ0332oo. tl03l2oo. 3928218. 371J9757. 351l5788. 3711l1J7. 1960 2 33<;7525,. 3177b21. ,?996/JblJ 2833?61. 217blb3 30I:I8CJ71,. J7 ?2Jbb. ljOJ32oo. tj033i?OO, 3937256. 37bi1JliJ. 3SIJ6711b, 31l389o7. 1961 3 331JJQ8o 3lb0911 291!1815. 28211690. 2722736 3032053 3686391. ''0332oo. ll03320IJ. 3913338, 3738685. 3519172. 3415Bob. 1%2 4 Bo7oOU 1 .511 LloSo. ?918324, 275328'3. 26811231 2797895 3115 329 2. 11033200. 4033200. 39bo1So~ 37951190. 3581683. 33&q91B. 1963 s 33~1876, 3lbb690. 29790118. 2822339. 276liJOb 3080719p 3579tjl2. 11033200. 11033200. 3916289, 3 7tPI3 711. ~527616. 31117tat. !96Q -6 33ttl9t .5110578. ?915599. 27511189. 2o53tJ70 2693051 33301160. 381118611. 11033200. 3%9722. 37192111, 35501132. 33?b3J3, 1965 7 3332100 3137986, 291Jl806. 2783110. 2719771. 3017835 3512089. 3968230. 11033200. 3959822. HB79o7. 351197119. 3397!]9. 1966 8 331J021t, lt52532. 2q6B27o. 283~51.12. 278b90b 31'lb007 p 39099110. 11033200. 1103321)0. 3965172. .38111165. 3589111. !llb11296. 1%7 9 3379757 3188885 J0095ll3. 2661q3'11, 2872700 31750911 38271189. 11033200. IJ033200. 389971l9. 37lllb08. 3tJ8520B 0 31156181. 1968 1 0 32728/lt: 3087057 2902100. 2755605, 21J95HO. .3085~99 .. 3700270. !991830. 3995875. 3990379. 3811112711, 3620075. 311117tll. 1969 1 I 31jo8o3o 3221J007. JOII97b8, 2918t7t. 2883985 3125 llll 3b08bl7. 39112521. l91l30SS. 382b882 3&11/jaqs. 3110b!t!8, 31ll52o2. !970 -~1EAN 3381:110/J 31968119. 3011520. 2859•121. 2811753 3080890 3669tlll. 399511110. 11021612. 3933907 • .37blt06. 3538339. 3~38863 r-11\X 3tlJ19.53: .561JIIIjl5. ~1159987 3311Jb0b 0 3H212S 3b27219,. IUJ33200 ljQJ3200. 1103.3200. 3990379. 38111J2711, 3b2oo7s. 37111117. MIN 32728 1H 3087057. 2902100. 27~3285. 2653£170. 2b93051 3330IJ60 381ll6bll. 39113055. 382b882. 36~11895. 31l0blliB. 33263J3. - - I_- PROJECT lll87900i - E,tl,P, LAKE LEVEL Ill FEET YEAR JAN FEB MAfl APR I 1100, II 0 0. 1080 JOb0 0 2 lOBO lObO. 1 0 II 0 • 1ollo. 3 tnBo, lObO. 1 Oil 0. 1040. 4 tooo, I ObO • 10110, 1020. 5 lOBo, lObO 10110 I .JIIO • b lObO lObO. lOilO. to2o. 7 tobo' lObO. 1040, 1o11o, 8 lOBO,. lObO 10 /j 0. 1ouu. q lOBO lObO, 10110 1040. 10 lObO, lObO l Oil 0, 1020. II lOBO lObO. 10110 1(140. MEAN I07S IObll, 1 0 /j/l • to:Sb. HAX 1100 1100. lOBO. IObllo MIN I Obo' lObO, 1040 0 I021Jo ... .... ..... looot ..., """' looot CHAKACHAHNA PROJECT OPERATIUII STUDY HIH.H~CF,HECHTEL CIVIL&MINERALS INC.,SF, ALASKA POWER AUTHORITY DATE 323B3 ALTERNATIVE Ci CHAKACHATNA TUNNEL, WITHOUT FISH RELEASES HAY JUNE JULY AUG SEPT OCT NIJV 1080 1100, 112 0. 112 0. 1120, 1120. II 0 0, 1 OliO lObO 11 0 0. 1120. 1120. 1120 1100, liJi'O~ 1040~ 1100. 1120. 1120. 1120, 1100, 1020, lotio. lOBO 1120. 1120, 1120. 110 0 • 1020 lObo, 1080, 1120, 112 0. 1120. 1100, 1020 1020 lObO, 110 0. 1120, 1120. 1100, 1020 lOilO lOBO, 1120, 1120. 1120. 1100. 10110 lObO, 1100. 1120. 1120. 1120. 11 ('10. 1 OliO lObO 1100. 1120, 1120. 11 no. ll 0 0. 1020 lobo,. 1100. 1120. 1120, 1120 1100. lOilO lObO lOBO. 1120. 1120. 1100. I I 0 0 • I 033 loSS 1091 • 1118 0 1120. Ill b. 1100. 1080 110 0. 1120. 1120. 11 2 n. 1120. 1100. 1020 1020 lObO • 1100. 1120. 1100. 1100. PAGE DE:C AVEYR lOBO, I 098. 1080, 101!0. loBo. i077. loBo. 1072, lOBO, 1077. lOBO. 1067, loBo. 1073. lOBO, lOBO, lOBO, 1076. 1100. 1017. 1060 0 1077. 1082. 1078, 11 0 0. 1oqa. toBo. I Ob 7. I ,_ 9 CALVR 19b0 l9bl 190? 19b3 19bll 1965 !9b6 19&7 19oB 19b9 1970 c CHAKACHMINA PROJECT OPERATION STIIDY HI H, li ~ C F 1 BECHTEL C I VI L & M PJ ERA L S !NC.,SF. PROJECT lliAHOOI ALASKA POWER AUTHORITY DATt. 32383 PAGE I 0 ALTERNATIVE Ci CHAKACHATNA TUtiNEL 1 WITHOUT FISH RELFASES WATER BALANCE YEAR JAN FEB MAR APR NAY JUNE JULY AUG SEPT OCT NOV ot.c AVEYR CALYR 1 . 0. 0, 0. n 0 0. 0. 0. Do 0. 0 I 0 0 IClbO o, 2 0 0 0. 0. 0 0 0. o. 0 I 0 0. Oo 0 1 I qb I 3 , o. Oo o. 0 0 0 0. Oo 0. o. 0. 0. 1%2 o, II o, o. o. o. 0 0 o. 0. 0. o. 0, 0. 0. 19&3 5 0 0. o. 0 0 0 o. 0. o. 0 0 0. o. 0 I 0. lqbQ b o, o. o. 0. 0. 0 0. o. Oo 0. o. 0 0 0. lqbS 7 o, u. o. 0. 0 0 n o. 0. o. 0. 0. o. 1q66 B o. u I o. 0. 0 0 o. 0. 0 0 0 Oo 0 1 0. 19b7 q o,. 0 I o. o. 0 o,. o. o. o. 0 0 0. 0. o. 1%8 10 o, 0. 0. o. 0 o, o. o. o. o. 0 0 (l I 0. i%9 11 0 0 0, o. 0 0 0 0. 0. 0. 0. Oo 0 0 1970 'lEAN 0 ' 0 0 0. o. 0 0 0. o. o. o. o. 0 0 0. MAX o, o. 0 o. 0 0 II • o. 0. 0. o. 0. 0. MIN o. u. o. 0 0 0 0 0 o. o. o. Do o. 0 0 ~ ~-, ~-~, r , .. r-,., ' ~ l _} ) A I I I -------I ~_!,. -~_] -~~ -~· -CHAKACHAMNA PROJECT OP~RATION STUDY H/H,H&CF,BECHTEL CIVIL&MIN~RALS INC.,SF, PROJECT !lli.!7900t ALASKA POWER AUTHORITY DATE:. 3.!383 PAGE I l .... ALTERNATIVE Cl CHAKACHATNA TUNNEL, lilTHUUT FISH RELEASES POWER Ill Hw - YEAR JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DE:.C AVtyR CALYH -I lBO~ 170. 1'53 t37, 125 121 119 125. 137. 157 tao. t9b, i':i 0 • 1%0 2 1BO, 170. !53 13 7. 12~ 121p 119 125. \37. 15 7. tao. t9b. 150, 1961 3 tBn 170. 1~3 137. 125 121 119. 125. \37. 157. lBO. t96. 150. !962 lj tao, 170 153. 137. 125 121,_ 119 125. 137. 157. 180, 196, 1 s 0. 1963 5 lBO 170 153. 137. 125 121 119 125. 137. 157. lBO. t96, ISO, 19611 b tBo, 170 153 13 7. 125 121 .. 119. 125. 137. 157. lBO. 196. 150, 1965 7 tao, 1 7 0. 153 137. 125 121, 119. 125. 137. 157. 180. t96. ISO 19bb 8 tao, 1 7 0. 153. 137, 12'5 121 11 9. 125, 137. 157. 180, i96. l"iO, 1967 9 tao, 170. 153, 137. 125 121 11 q 125. 137. 157 lBO. t9b. 15 0. 1968 10 tao, 17 0 0 153. 137. 125 121 119. 125. 137. 157. 180, t9b, Is o. 1969 1 1 lBO 170. 153. 137. 125 121 119. 125. 13 7. 157. lBO. 19&, 150. 1970 HEAN 180 170. 153. 137. 125 121 119, 125. 137. 157 180, 19&. 1 so. -HAX tao, 1 7 0. I 53. 137. 125 121 119. 125. 13 7. 157. 1 fl 0. I 9b • I "i o. HIN 180 170. 153 137. 125 121 119 125. 137. 157. I BO. 196. 1 "i 0. PROJECT EIIERGY YEAR 1 2 3 II 5 6 7 8 9 1 0 1 I liE AN ~1AX MIN 1487900l IN HHH JAIJ 1l392o llH2o,. 1l392o 1U92o, 1 U92o, ll392o I'B92o, 133920, I '3920 1l3920f 133920 1U92o' 133920: 133920 FE I.! 118471. 11113136. I!IJ386. IIIJ386, I !8 IJ 71 • IIIJ38b 0 I!IJ38b 114386, I 181171 • Jt/J38b 1111386, 115~00. 1 181l71 111Jl86 I _ _. MAH APR l I 3!llll • 98b0'1. 11 35111 91!609. 1135111. 98b09. 113':111 1. 98609. 1135111 98b09. 1135111. 9'8609. 11 351J I • 98b0'1. 11 35111. 98o0'1. lt35ll1. 98&0'l. I I 3 Sll I • 98ol)9• 1135£11. 98b09. 1135111 98u09. 113541 98bO'l. 11351ll 96&09. \, CHAKACHAHNA PROJECT OPERATION STUDY I,. H/H,HI!.CF,BECHTEL CIVIL&MINERALS HIC.,sF. ALASKA POWER AUTHORITY DATE 32383 PAcE 12 ALTERNATIVF Cl CHAKACHATNA TUNNEL, WITHOUT FISH RELEASE 'I .... MAY JUNE JULY AUG SEPT OCT NOV DEC TUTYR CALYH 931£.2 67339 88795. 931b2. 9Bbo9. 1161152, .... 129bOO, 1115565. !317221l. 19&0 93162 87:539 88795 931b2. 98bo9. 1161152. 129&00, 145565. 1313139. !961 931&2 87339f 88795. 93162. 9Bb09. 11 &1152. 129bOO, 145565 0 1313139. 19&2 93Jb2 117 339 r 887<15. 93162. 98&09. II 6 II 52 • 129&00 0 11155&5. !313139, 1963 931b2 'l733Q f 88795. 931&2. 9Bb09. 11&1152, 129bOO. 11155&5. 13172?4, 19bll 93!b2 A7339 88795. 931&2. 91.1609. 11 6 II 52 , 129600, liJSSbS. !313139. 191»5 93lb2 87339f 88795. 93162. 9Boo9. 1161152. 129600. lil5565' 1313139. 1966 93162 1!73!9 88795. 931&2. 98&09. 11bll52. 129&00. 11J5Sb5 0 1313139. !9&7 93lb2 87339' 88795. 931&2. 913b09, llbl~52. 129&oo. 1115565. !3172?/j. 19&8 93162. 87339 8879';. 931&2. 98&09. 11biJ52. 129&00. 11J55&S. 1313139. 19&9 93tb2 87339 88795. 93162. 981,09. 1161152. 129&00. l455bS 1 1313119' 1970 931u2 87339 88795 93162. 98&09. 11&452. 129600. 11155&5. 13142c;3. 9:Sib2 87339' 88795. 931&2. 913&09. ll6ll52. 129600. 1q5S65a 1317224. 931&2 87339' 88795. 93162. 98b09. 1161152. 129600. ltJSSbS. 1313139, ~-l c_] G r ~l (_] r ~ ~ -I L--::___ ~ ,--1 _....~-~ ...--~I r -f~ ~ 1\ I \ L--...,.-I L~_l ._. l~---L-I L-,. _( I I ~-J, L~ _ ___, L-~~ '----..--l ....... CHAKACHAHNA PROJECT OPERATION STUDY H/H,Jt&CF.BFCHTEL CIVIL!i.HINERALS INC.,SF, PROJECT 141179001 ALASKA POWtR AUTHORITY DATE:. 32363 PAGE 13 ..._. ALTERNATIVE Ci CHAKACHATNA TUNNEL, WITHOUT FISH RELEASES ENERGY DEFt ciT JN M IH ..... YEAR JAtJ FEB MAR APR ~lAY JUNE JULY AUG SEPT OCT NOV DEC TOTYR CALYR .... 1 , 0 o. 0. o. o, II, o. o. o, 0. 0. 0. 19b0 o, 2 0 o. 0. o, 0 0 o. o. o. 0. o. 0. 0. 1%1 '-' 3 o, o. o, 0. 0 o .. o. o. 0 0 IJ • 0. 0. (1, \9b2 q o, 0. o. o. 0 o. o. o. o. 0 0 0. 0 0 0 0 \9bl 5 o, o. o. o. 0 o, o. o. 0. 0. 01 0. 0. \9&11 ~ b 0 0. 0 I o. o. 0 o. o. 0 1 0. 0 1 0 1 0 1 19b5 7 0 o. 0 o. 0 0 o. o. 0. 0. 0. o. 0' l9bb 8 , 0 o. o. 0 o, o. o. 0 0 Q I 0. 0. 0. 19&7 o, ~ 9 0 o. o. o. 0 0 o. o. o. o. 01 0 1 o. 19b8 1 0 , 0 01 o, o. of o. o. 0. o. 0. o. 0. 19b9 o, II 0 0 o. o. 0 0 o. o. o. o. 0 1 o. o. 1970 .... liE AN 0 0. o. 01 0 0 o. o. 0. o. o. 0 1 0. HAX 0 0 o. o. 0 o' o. o. o. 0 0 0. o. HlN o' o. 0 0. 0 0 o. o. 0. 0. 0. 0. o. ... CHAKACHAMNA PROJECT OPERATION STUDY "' H/H,It&C.F,BECHTEL CIVIL&MINERALS INC.,SF. PROJECT lll87900t ALASKA POWER AUTHORITY DATE 32383 P~GE 14 ALTI:.RNATIVE C& CHAK ~CHA PIA TUNNEL, IH THOUT fiSH RELf'ASES AVERAGE. GENERAT rOrJ IN HW IN MONTHS Uf SPILLS YEAR JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVEYR CALYR I n, 0. o. o. 0 0 2Jb. 3oo. I bO • o. 0. 0. sa. 19&0 2 o, 0. o. o. 0 0 o. 299. :soo. o. 0. 0 1 so. 19bl .3 n, 0 0. o. 0 o, 0. 241l. 282. 0 1 0 1 0 I 4IJI 19b2 q n, u o. I). 0. o,. o. 1112. 297. 0 0. 0 1 37. !9b3 5 u, 0. o. o. 0 0 o. 22b. 21&. o. o. o. 371 1%11 b 0 0 o. 0. 0 o, o. o. 3oo. o. 0. 0. 25. 19&5 7 o, 0 I o. 0. 0 0 o. o. 280. o. 0. o. 23. 19bb 8 0 0 o. o. 0 0 o. 3oo. 300. o. 0. 0. so. 1967 9 . 0. 0 0 o. 0 o,. Joo. 142 0 o. 0. 0. 37. 19&8 o,. o. I 0 o, 0. o. o. 0 0 o. o. 0. o. 0, 0. 0. 1969 II 0 0. o. 0. 0 0 o. o. 0. o. 0. 0 I 0. 1970 ~IE. AN 0 0. 0 o, 0 0 21. 165. 207. 0 o. 0. 33. MAX o, 0 o. o. 0 0 236. 300. :soo. o. o. o. sa. MIN 0 0. 0 1 o. 0 0 o. 01 0. 0 0 o, 0. 01 ) _J r-_-....-~ ,~ .. 1 --, ~-~ ~~ ~ ~ r-----~ C~-~ l _ ___~ ) ..,.,..---...:. 1.__ l _? L_ --l __ J L~- CHAKACHAMNA PROJECT OPERATION STUDY HIH,H&CF,BECHTEL CIVIL&MINERAL.S INC.,SF. PROJECT 111879001 ALASKA POWER AUTHORITY DATE 3Z383 PAGt. IS ALTERNATIVE Cl CHAKACHATIIA TUNNEL., WITHOUT FISH RELEASES SURPLUS EtlffHoY Ill Ho'IH YEAR JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC TOTYR CALYR ..., , I o, 0. o. 0. 2 o, o. o. o. ""' 3 0 0 I o. o. 0 0 8bb81, 130038. 16519. o. o. o. 233238. 1960 0 0 o. 129139, 117391. o. 0 D 0. 2t!b5JO. 19&1 0 0 o. 88319. 101.12&11. o. o. o. 192583, 1962 II o, o. o. o. 5 0 o. o. o. I). 0~ o. 12317. 1151.129. o. 0, o. l277tJb, 19&] o. 0 o. 7llbb0 0 ~b822. o. o. o. l311182. 19&lJ '-1 b o, 0. 0. o. 7 o, 0. o. o. 8 o. 0. o. o. o. o,. o. o. 117391. o. o. o. 117391. i9h'5 0 0 o. 0. 103318, 0, 0. o. 103:3t8, 19bb 0 0 o. 130038. 117391. o. o. 0 I 2117430. 19&7 lai 9 o, 0. o. o. 10 o, 0. o. o. I I 0 0. 0. 0. 0 o, o. 130038, 3oB. 0. 0. 0. 13lb71. 19&8 0 -o, o. 0 I a. o. 0. 0. o. 19b9 0 0 o. o. o. 0. 0. o. 0. 197a ..,; , HEAN 0 o. o. o. 0 0 7880. b31tl1. b8378. 0. 0. 0. 139399. \lid MAX o, o. o. o. MIN 0 0. o. o. o. o, 8bb81. 130036, 117391. 0. a. 0. 2!171130, 0 0 o. o. o. o. o. 0. 0. ""' ~ w 'otJ ..,; loti t,J ..,; .., \J -........, --Ait \od ... CHAKACHAMNA PROJECT OPERATION STUDY .. H/H,H~CF,BECHTEL C IV I L&~l I NER AL.S INCpSFo PROJECT 11187900J ALASKA POWER AUTHORITY DATE 32363 PAGE 16 ALTERNATIVE Cl EHAKACHATNA TUNNEL, WITHOUT FISH RELEASES REMAINING SPILLS IN CFS YEAR JAN HB MAR APR HAY JUNE JULY AUG SEPT OCT NOV DEC AVFYR CALYR I 0 0 0. a, 0 0 o. 31170. 0, 0 0 I 0. 289, 1960 2 o, 0. 0 0, 0 o, 0 01 3211. o. 01 0. 27. 1961 3 0 0. 0 a. 0 a o. 01 a. 0. o. Q. o. 1962 q o, o. 0, o. 0 0~ o. o. 0. 0, a. I) I 0. 1963 5 o, 0 o. o. 0 o,. o. a. 0. o. a. 0. 0. 196tl b 0 a. o. o. 0 a, a. a. 1232. 0. 0. 0. In 3. 19&5 7 , Oo a. 0 0 o. o, a 0, 0 o,. a. o. 0. 0. 19bb 8 o, a. Q 1 o. 0 o, o. 7823, 290. 0. 0. ll, 676, 1967 9 0 0. o. a. 0 o. o. 2alltl. 0. o. a. 0. 170 0 I%A 1 0 o, 0. 0 o. 0 o, o. Oo a. 0. 0 0 0. 0. 1969 1 1 0 a o. a. 0 0 o. o. a. a 0. 0. 0. 1970 MEAN o' 0 o. o. a a. a. 1212, 168, 0 0 0 0. 115. MAX , 0 a o. 0 o, 0 7823. 1232, (), 0. 0. 67b. o, HlN 0 0. 0, a. 0 0 0, o. 0. 0. a. 0. a' -, -_, PROJECT I4A790nj ~ INSTALLED CAPACITY! 100000 KW ANNUAL. fJl.ANT fACTIJR! 5 OVERLuAD fACTORs 00 ,850 FRICTION Ln&s coEFFICIENTs 000002800 ' ... MONTHLY LUAO no .a7o JIIITIAL LAKE HINIHUM LAKE MAXIMUM_ LAKE FAcTURSI '7ao STORAGE STOIHGI;. STORAGE 700 , btiO 620 ,11033200. AC .. FT 12ll23bu0o AC•FT lll03l200. AC.,fT 610 C H AK ACHA I~NA PROJECT OPERATION 5 TIJD V HIH,H&CF,BECHTEL CIVIL&HINERA~S INC.,SF. ALASKA POWER AUTHORITY ALTERNATIVE Di CHAKACHATNA TUNNEL 6 WITH FISH RELEASE& 6110 700 ,600 920 I 000 L L~ -l DATE 32383 CHAKACHAHNA PROJECT UPERATIUtl STUDY ti/H,HI!.CF ,BECHTEL CIVIL&'1INERALS INC.,sF. PROJECT 11lA79ool ALASKA POWER AUTHORITY DATE 32383 PAGE: 2 ALTERNATIVE Dl CHAKACHATNA TUNNEL, WITH FISH RELEASES RESERVOIR STUHAGEaELEVATIUN•AREAI AC~Fr FEET ACRE 0. 7b0, o. 2025. 765 810 7~oo, 770. l 300. 27;lOO, 780, 2b90. 111ooo. aoo. 5b70. 21llooo, 820. 7.320. 397ooo. 81l0, 1:1270 572ooo, BbO, 9280 769ooo. 880 101100 98Booo. 900 11590 1221looo. 920. 11960. 14o7ooo. 940 12320 1717ooo, 9b0 ltlb50 1973ooo. ?80, 12980. 223booo, 1000 1328(1 250tlooo. 1 u2 o. 13520. 277t.ooo. toiiO I HIIO 3053ooo, lObO 139bO, H3Sooo, lOBO. I u 1 7 0 3o20ooo I I 00 I U390 l910ooo. I 120 • 111b20 1.1033200. 1128 I <;212 • TAILI'IATER-FLOW RELATIONSHIP I FEET CFS IJOO 0 40o looooo MONTHLY MINIMUM Ill5THEAM FLOWS IN CFSi 30, 3o 30 30, 30 30. 30. .so 30 30. 30. 30. MONTHLY Dl VERSION RE.QUIREt~F-NTS IN CfSi o. 0 0. 0. 0 o. 0. 0 0 u, o. 0. MONTHLY RESERVOIR EVAPOHATJON I II lllCHES, 0 0 _o, 0 0. 0 0 o. 0. 0 0 _o._ --0 o. '!!" ..J "' -.f _j L-.-l ~~~l \=~= ~--~\ 1---,-r---1 r~, .. ---, ----, I r-~, c--= r I I I I \..__ _ l_-J I __.,_ __ ( I l __ I L __j l ~---' __ J --- CHAKACHA~NA PROJECT OPFRATIUN STUDY HIH,H&CF,BECHTEL CIVIL~MIN~RALS INC.,SFI PRUJECT lllfl79001 ALASKA POWER AUTHORITY DATE 32383 PAGE. l ALTERNATIVE Dl CHAKACHATNA TUNNEL, WITH FISH RELEASES INFLO..JS TO THE LAI'E IIJ CFS YEAR JAN FE.B MAR APR ~tA Y JUtlE JULY AUG SEPT OCT NUV DE.C AVEYR CALYR ._ 1 jJ oo, 307 2b7. ]93. 3b31 b8l7 11209. 9337. 3ll15 0 11J39. 799. 870. 3220, l9b0 2 an' !>69. IJ70. 3116. 1881 H83, 128o8. 10899. 6225. 1586. 8113. o96. 37o7. lQbl 3 b33' SLII. 1171 1 u7o, 12b5 7925 13149, I 01111 • 55421 II 97 863. b 13' 35qo, 1%2 Ll 1198,. .SS7. 315. 337. 18 u 1 4735, 13249. 12208. 58117. 20561 ' 930. 71 0 0 3587. 1963 5 loll Ll35 332. u77o 1830 8093 10700. 11798. 11211&. 121l5, 909. bb2. 311211. t9bll b IJ19, 219. 337. ]98o 126b 3490~ 130116. 1051b. 10802. 21lll. 597, llbb, 3biJ1 0 !965 7 388, 33b, 350. lj 1 0. 1893 8072 10303. 99711. bbOB. 1953, 9 I 0, 313. 3tl'i9 1 19bb 8 531, 11119. 38110 8Bo. 2030 87b1 111931 0 1Sb95 0 b 191. 20110. 121 s. s 71. '11173, t%7 9 S.Sil, 5 I 0 • llb7. b30o 299b 7808 13117. 11257. 27 1)3, 97b. b89, bl2. 3532, !9b8 1 0 -u8s, tl6b. soo. b52. 19118 9271 12510. 7297. 2793, 3057. 121 5. 541. 3Hb, t9b9 II IJ97 SOli. sso. 899, 22b5 b769 I03bO, 79Bb. 27311, 1359. 7112. llbO, 2929. 1970 HEAN 5 It , 1130 11011, s3o. 207b 7251 12307. 10671. 5175. 1729. 883, 592, 35117, MAX an: !)89 sso. S9Q• 3b37. 9271, t/1931. 1Sb9S. 10802. 3057 121 s 0 8701 11117.3. MIN 3(111 219. 2b7. 337. 12b5. 31!90 10303. 7297, 2734, 97b. 597. 313. 29?9, dJ >ttl CHAKACHAMNA PROJECT OPERATION STUDY 1li87900J tllli,H&CF ,bECHTE.L CIVIL&MINERALS JNC,,!:IF'. PRoJECT ALASKA PO~ER AUTHORITY DATE 32383 PAGE ALTlRNATIVE Di C~AKACHATNA TUNNEL, HITH FISH RELE.ASE.S POWER RELEASE HJ CFS YEAR JAN FEB MAR APR MAY JUNE. JULY AUG SEPT OCT NOV DE:C AVEYR CALYR l 3673 3567. 326o, 290.5. 2726 2550 21129, 21178, 307b. Jlllb 37Q8, tq67. J1sn. IQbO 2 HH: 3828. 3384. 31 11 • 2821 2727. 2507 21179. 2725, 31llb, 3798. tq87. 32?1. I qb I -3 3939 3828. 3381 0 3111 • ?923 2727 250b, 2555. 2725. 31116, 37Qa. '1343. 32uB. 19h2 4 HH, 3831. 3508, 3111. 2924 2625r 2591. 2556. 2725. 31Lib. 3798. 11167. 3262. l9b3 5 3Cl39 r 3628, 3381. 3 111 • 2923 2727, 2590. 2556, 2725, 31llb, 37Q8. 4187. 321J3. 1Clb4 b 39H 3831. 350B. 3111 • 292/1 2625 268o. 21:136. 2725. 31llb, 3798. 11187, 3276, 1Cl65 7 3939, 3831 3508. 3 111 • 2924 2727, 2590, 2556, 2725, !tllb, 3798. 4187. 32s.s. lClbb 8 3ClH, 3831 3508, 3111. ?821 2727, 2507. 21179. 2725. 3146, 3796. 1.1187. 3232, 1Clb7 ~ 9 39JQ 3828 33811 3 I 1 1 • 2821 272b 2507. 2479. 2725. 3146, 38no. 4343, 32]4, 1908 1 (J 3939, 3831 3508 3111 0 2Cl21J 2727, 2507. "\ 2555. 2725, 3146. 37Q8. tq87. 321J 7. 1Clb9 11 393Q 3828 3384 31 11 • 2821 2726 2590, 25!16, 2811. 3249, :saoo. 4348. 32b4. 1970 .,; H1s' liE AN 380b. 342Q 3092. 2BbB 2728 254b. 2535. 2765. 3156 3799. 4230, l2J9. HAX JQ39~ 3831 3508, 31 I t , 2924 2825, 2b6n 2638. 3076. 3249 3600. IJ34B. 327b. HIN 3b73 351:17 32ob. 2903. 2726 2550 2429 • 21J78. 2725. 31116. 3798. 11187. 31sn, ..,. ..,; 4 <tl <IJ f) _L..;l ..,/ ,= L~ ,_ -\ ~I r -r--~- ( ( ~ ,__ '-~-I '---- .... CHAKACHAMNA PROJECT OPERATION STUDY PROJECT lli8HOO I H/H,H~CF,UECHTEL CIVIL&MINERALS INC.,SF. ALASKA POWER AUTHORITY DAH. 32"383 PAGE. 5 ALTI:RNATIVE Dl CHAKACHATNA TUNNEL, WITH FISH RELEASE& SPILL ItJ CFS YEAR JArJ FEB MAR APR HAY JUNE JULY AUG SEPT OCT NOV DEC AVE:.YR CALYR I o, 0 0 o. 2 0 0. o. o. l o, 0. 0. o. /j o, 0 Do 0. 5 o, o. o. o. b o, 0 o. o. 7 0 o. o. o. 0 o, 1882 6829. 39. 0. o. 0. 729. IQbO 0 0 0 0 30110. 31170. o. o. 0. 5u3. 1961 o. 0, o. 1B9bo 2787, 0. 0. 0. HO o 1962 , 0 o, o. o. 2820. 0. o. o. 235. 19b3 0 o, o. 11138. 11191. 0. 0. 0. 2llll. 19bll 0 o, o. o. IIOLI2 0 o. o. o. 337. 19b5 0 0 o. o. 21125. 0. 0. 0. 2o2. !9bb 8 • 0. 0. 0. 0~ q 0 0. o. o. 0 o' o. 10757. llllb. o. 0, o. 1183. t9b7 0 o"' 0. 5108. 38. o. o. o. 1129. 1968 - 1 0 01' o. 0 o. 11 0 o. o. o. 0 o,. o. o. n • o. o. 0. 0. 1Qb9 0 0 0. o • 0. o. o. 0. 0. 1CHO MEAN . o. 0. o. o. 0 o' 171. 2bll2. 1868, o. 0. 0. ]qO • MAX , o. 0 0 o. 0 0 1882. 10757. 110112. 0 0. o. 11 A3 • MIN . 0. o. 0. o, 0 __ 0 o. o. 0. o. o. 0 0 0. CHAKACHAMNA PROJECT OPERATION STUDY H/H,H&Cf 1 BECHTEL ClVIL&MINERALS INC,,SF. PROJECT lllA7900! ALASKA POWER AUTHORITY DATE 32383 PAGE b ALTERNATIVE Dl CHAKACHATNA TU~INEL, WITH FISH RELEASES FISH RELEASE IN CFS YEAR JAIJ FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV D~C AVEVR CALYR \ ""' I 3o, 30 30. 30. .so 30, 30p 30. 30. 30 30. 30, 30, lllbO 2 3o, 30. 30. 30. 30 Jo, 30. 30. 30. 30. 30. 30. 30. I 9b I 3 3o, 30 30. 30. 30 3 01 30. 30. 30. 30 30. 30. 30. l9b2 . .._ ~ 3o 1 30. 30. :so. 30. 3o, 30. 30. 30. 30. 30. 30. 30. l9b3 5 3o, 30. 30. 30. 30 30, 30. 30. 30. 30. 30. 30. 30. l9b~ b 3o 1 30. 30. 30. 30 30, 30. 30. 30. 30. 30. 30. 30. 1965 'OJ 7 3o, 30. 30 3o. 30 30, 30. Jo. 30. 30. lo. 30. 30. 19bb B 3o, 30, 30. 30. 30 30 30. 30. 30. 30. 30. 30. 30. 1967 q 3o, 30. .50. 30. 30 30, 30. 30. 30. 30. 30. 3 0. 30 • 1968 -1 0 3o, 30. 30. 30. 30 30. 30. 30. 30. 30, 30. 30. 10. 1969 II 3o 30. 30. 30. 30 30 30. 30. 30. 30. 30. 30. 30. 1970 ' "" MEAN 30. 30. 30. 30. 30 30 30. 30. 30. 30 30. 30. 30. MAX 3o, 30. 30. 3o. 30 Jo, 30. 30. 30. 30. 30. 30. 30. HIN 30 30. 30. 30. 30 30 30. 30. 30. 30. 30. 30. 30. I I ~-J _j -, I ~ ~~, r-{~-~ '1 l_ ~ ~--.. 1--l r--, ~~~-( -I ~ _j '--~ c__j __ I _! l _ --.._______) -J I L ~) - "' CHAKACHAHNA PROJECT OPERATION STUDY 1487900l HIH,H~CF,BECHTEL CIVIL&MINEHALS INC.,SF, PROJECT ALASKA POriER AUTHORITY DATE 32363 PAC. E. 1 ALTERNATIVE Dl CHAKACHA HIA TUNNEL, WITH FISH RELEAS~S ,NET EVAPORATION IN AC .. fT ... YEAR JAN FEB MAR APR HAY JUNE JULY AUG SEPT OCT NOV DEC AVEYR CALYP -I 0~ 0. o. o. 0 o, o. 0. o. 0. o, D, o. l9b0 2 o, 0 1 0, o. 0 o, o. 0. 0. o. o, 0. 0 1 19bl ... 3 0 o. o. o, 0 0 0, o. o. o. 0 1 o. 0 • l<lb2 lj . o. o. o. 0 o, o. o. 0, 0. o. o. 0. l<lb3 o,. 5 0 o. 0 I o. 0 0 o. o. o. 0. 01 0. 0. l9btl 6 I o. o. o. Do o' o. o. o. o. o. o. 0. lqb5 -o,. 7 o,. 0 0, o. 0 o'" 0, o. 0. 0. o. o. 0. l9bb 8 o, 0. o. o. 0 o' o. 0. o. 0 1 o, 0. 0. 19b7 -q o, o. 0, 0. 0 0 o. o. 0. 0, 0. 0. 0 0 19b8 I 0 o, o. o. 0. 0 o, o. o, o. o. 0 1 0. o. lqbq II n o. 0 0 1 0 0 o. o. o. 0. 0. 0. 0. 1q7o ... ~lEAN 0 0. o. 0, 0 o' o. o. o. 0, 0. 0. o. HAX o, o. 0 0, 0 o' 0 o. 0. o. 0. 0. 01 HIN 0 0. o. o. 0 0 .. o. o. 0, o. 0. 0. o. - .... CHAKACHA~NA PROJErT OPERATION STUDY H/M,H&Cf,RECHTEL CIVIL&MINERALS INCH:,F. PROJECT lll8HOOt ALASKA POWER AUTHORITY DATE 32383 PAGt A ALTERNATIVE Di CHAKACHATNA TUNNELP WIPi F"I SH RELEASFS E,O,P, STORAGE JN ACREooFT YEAR JAN FED MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVEYR CALYR I 38Joo88 JbtJ08411 11154572. 33031106. 3357590 3&10899 1103320(1 11033200. 111133200, 392&373 0 37116127, 351103111. 37n9tst, t9bO 2 3l'i020b., 3lb81.l36 i'987b3S. 262t311b, 27617ol.l 3072b87p 3701~237. 11033200, 11033200. 39 351112. 37577811. 35CI1272. 31J30bt0 0 19b1 3 33Jblbl 31'Jt92b. 29711bB. 2812258. 27081159. 30!5'191 3668577. 11033200. 4033200, 3911493. 37350Sb. 3503872. 34067Ao. t9b2 II 32901100~ 30956115. 2897bb8 0 273081111. 2b599Ub 2771625, 3 11253115. 4n17oo5. 4033200, 391:1113!1 0 3791860, 357&209. 335451.13, 1963 5 Bc;us57, 3t51ol.l5o 291:16341, 26098117. 27110789 30'JB318 355Sibo. II0332oo. 4033200. 391414114. 3711071111 8 3522it11. 340736b 1 !964 b Bo3872, 310!593. 29011769, 2741575. 2639010, ao76Bo7' 3312371. 37911930. 11033200. 39b7877. 31756\2. 351111957. 3316381 0 !965 7 Btll.l76 1 3129000. ;l932 1'nb 0 277otJ9S. 27052511 30?1533 3ll9H42. 3946239. 11033200. 3957978. 378113371 35411275. 3387167, t9&6 8 3332892, 31£13387 ?94?t152, 26111939. 276 111159 3121736, 38638211o LI033200 • 11033200. 39b3327. 3607635. 3583637. 311521.:157. 19b7 9 3372436 317981.10. ?998654, 2849265. 2858181. 3158790 36093tiO. 11033200. tlo332oo. 38979011. 3710979. 31179733, 341181160 0 1968 1 0 32t-552(1~ 3078072. ?891270. 2743190. 2681330, 30bB9511, 3682181, 3971897. 397ll!56, 39obB16. 36113211. 3585281, 33933:33. 1969 11 337!807 3185517. "\009435. 287bu52. 28110021 3o7999o 3555938. 3887997. 386162b. 37b35t14. 3579772. 3338860. 3361.1215. 1970 MEAN 3375707 3181.1755 299b903, 2843u2o. 27921l31 305977b 3bll76tl7. 3983570. 110111053. 39211498. 37119221, 3523b88. 31l246ob, MAX 38lll088, 361J061.111 JIJS/1572 33031JOb. 3357590 3b10699' 11033200. ti033200. 11033200. 3967877 3811324. 3585261, 3709151. MIN _32t>5522 3078072o 2891270. 273o61111. 2639010 267oBo7' 3312371 379ti930. 366162&. 37635tlll 3579172, 33388801 3316381. L --" ~-~ I -\ '---=J r-~-I r-IIIli -~-l --, (--Wf \-I ) I I I __ _~ -~ _j ~ _J L_ ~ .... CHAKACHAHNA PROJECT OPERATION STUDY PROJECT tt1117qoo\ H/H,tii!.CF ,BECHTEL CIVIL&MI~'ERALS INC.,SF. ALASKA POWER AUTHORITY DATE 323!13 PAGE q .... ALTERNATIVE D& CrlAKACHA HIA TUNNEL, WITH FISH RELEASES E.Q.P LAKF LEVEL Jll fEET YEAR JAN FEB MAR APR MAY JUI~E JULY AU C. SEPT OCT NOV DEC AVEYR CALYR ... I 11 on, i l 00 1080, tnoo. to8o. 1080f 1120. 1120. 1120o 1120. 1100. 1 oao. IOq7. 1%0 2 1060 lOcO lOtiO. totlo. 1020 lObO 1100. 1120. 1120, 1120. 1100. 1 a eo. 1078, 1%1 3 1oao, lObO. 1040. 1o11o. 1020 lOtiO, 1100. 1120. 1120. 1120 11 0 0. 1 oao. 1077, JQb2 u lObO lObO. 1040 1020, 1020 1020 lOBO. 1120. 1120. 1120. II 0 0, 1080, l070o lqb3 5 toBo: lObO. !OliO. 1 ()II 0, 1020 IOb0 1 lOBo. 1120. 1120o 1120o 1100. toeo. 1077 0 lqbll b lObO lObO 10110. 1020. \020 1020. lObO. 1100. 1120. 1120. II 00 • toBo. 1067. IQoS 7 lObO lObO. 1040. 1020. 1Cl20 lOtiO lOBO. 1120. 1120. 1120. liOOo toeo. 1072. l%b 8 lObO, lObO. 1 Qlj 0. to4o. 1020 lObOp 1100. 1120. 1120. 1120. II 0 0 • toao. 1077, 1Qb7 q 1080. I OoO o I 0 4 0 • 1041), I Oil 0 lObO 11 0 0. 1120. 1120, 1100, I 10 0 • toea. 1078, \Q/)8 10 tobo, IUbO. !OliO 1020. 1020 lObO. 1100 1120. 1120. 1120 II 00. 1080. l07':l, lqbq 11 to8o lObO, 10110 totro. I Oil 0 lObO 1080 1100 • 11 0 0. I 1 0 0 o toao. 1080, 10 7 2' IQ70 .... HEAN to73' 10b4, 10411. 1035, l02Q 1051 lOQl. 111 b. 111 8. 111 b 0 IOQ8 0 1080, 107b, .... MAX II On r II 00. 1080 lObO. 11180 lOBO 1120. \120, 1121J • 1120 1100. I080o 10Q7. MIN 1000 lObO. !OliO. 1020. 1020 1020 lObO 1100. 1100, 1100. 1080 0 1080, \067. .... CHAKACHA~NA PROJECT OPERATION STUDY HIH.H&CF,BFCHTEL CIVIL&MINERAL~ INC.,SF. PROJECT lt18790o I ALASKA POWER AUTHORITY DATE 32383 PAGE:. 1 0 ALTE:.RNATIVE 01 CHAKACHATNA TUNNEL, IIITH f"ISH RELEASES WATER BALANCE YEAR JMJ Ffl:l MAR AP~ HAY JUNE JULY AUG SE.PT OCT NIJV DEC AVFYR CALVR I , o. o, 0 o, 0. 0. 0. 0. 0. 0. o, 0 0. 1960 2 o, o. 0. o. 0 0 o. o. o. 0. o. 0. 0. 1961 l o, "· o. 0. 0 of o. o. 0. o. o. 0. 0. 1962 II o, o. 0. o. o. -o, o. o. 0. 0. 0. 0. o, 1963 5 o, o. 0. 0. 0 0 0. o. 0. 0. 0. 0. 0. 19611 6 o, o. o. o. 0 o, o. o, 0. o. 0. 0. 0. lq65 1 o, 0. o. o. 0 0 o. o. o, 0. 0. 0. 0. 1966 6 0 0. 0. o, 0 0 o. o. o. o. 0. 0. 0. 1967 9 0~ o. 0. o. 0 o, 0 o. 0. o. 0. 0. 0. 1968 1 0 o, 0. 0. o. 0 o, o. o. 0. 0. OM o. 0. 1969 11 0 0. 0. 0. 0 0 o. o. 0. 0. o, 0. o. 1970 MEAN o' 0. 0. 0. 0 o' o. o. 0. 0 0. 0. 0. MAX o, 0. 0 o. 0 o' o. 0. o, 0 o. o. 0. MIN 0 0. o. 0. 0 o' o. o. 0 1 0. 0. 0. 0. (--- I '--' c--, ~--\ I r~-, c_-=--IIIII r-~ -' ---I I __ _) I L ________! , _ ___j l _ __j I ... CHAKACHA~NA PROJECT OPtRATIO~ STUDY 14R790ol H/H,H&CF,BECHTEL CIVIL&MINERALS INC.,SF. PROJECT ALASKA POWER AUTHORITY DATE:. 32383 PAGE. I I ""' ALTERNATIVE Dl CrlAKACHATfiA TUNNEL~ WITH FISH RELEASES POWER I r~ Mw - YEAR JAN FEB HAR APR MAY JUNE JULY AUG SE.PT OCT NOV DE.C AVEYR CALYR I tao; 170 153. t37. 125 121,. tl9. 125. 137. 157. lao. 196. triO, 191:!0 2 tao, 170. 153. !37. t25 121, 119. 1251 137. !57. tao. 196. 1'i0 1 1961 3 tao 1701 153. !37 I 125 121 1 I 9. 1251 t3 7. 157. tao. !96. I 'iO I t962 4 180~ 170 I t53. 13 7 0 t25 121,. 119. 125. 1371 !57. 180, 196. 1'501 1963 5 tao 170. t53, !37. 125 121 119. 1251 137, !57. !80._ !961 ISO, 19611 b tllo~ 170. !53. t37, 125 121,. 119. 125. 137. 1570 160. )96 I 150. !965 7 tao, 170. !53. 137, 125. 121, 119 125, 137, 157. 160. l 96. 1'50, t96o 8 teo, 170 D 153. 137. 125. li!l, 119. 125. 137. 157, tao. 196. ISO, 19&7 9 tao, 170. !53, 137. t25 121i' 119. 125. 137. 157. ta 0. )96. l so. t9&8 10 teo, 170, t53. 137 0 125, li!l, 119. 125. 137. 157 180. t96, I SO o 19bQ 11 lllO 170. 153. 137. 125 121 119, 125, 137. t57. 1BOo 196, ISO, 19 7(1 -t8n' MEAN 170. 153, I.H • 125 121 t 1 9 • 125, \37, 157, 180. !96, I '50, MAX t8o, 170 153 t37o 125 121' 119. 125. I:H. 157. 180, 19&. IS 0 • MIN l!lo 1701 153, 137, 125 121,. 119, 125. 137. 15 7. 180, 19&. ISO, ..,. - \ CHAKACHAMNA PROJECT OPeRAT!Oil STUDY .. I11879UOl H/H,H&CF,BECHTEL CIVIL&MINERALS INC.,SF, PROJECT ALASKA PU~ER AUTHORITY DATE 32383 PAGe 12 .. ALTERNATIVE D! CrlAKACHATNA TUNNEL 1 WITH FISH ReLEASES ENERGY IN MWH YEAR JMI FEB MAR APR MAY JUNE JULY AUG SEPT UCT Nf)V OE.C TOTYR CALYR 1 1 ~H2o 1181171 1135111. 98b09. q31o2 87339 68795, 93162. 96609. 11 bll52 129oou. 1115565, 13172?11. 1Cib0 2 I B92op 1111386. )135111, 9aao9. 931b2 87339. 88HS. 93162. ?86o'il. 1161152. 129600 0 1tl5So5. 1313139. I 9b 1 3 1 l392o 1111386. I I 35/ll. 98o09. 93162 873]9 88795. 93162. 98ba'il. 1161152. 129&oo. 1115So5. 1313139. 1962 II 113920~ 1!438b. 113541. 9Bo09. 93162 117339, 88795. 93162. 98oo'il. 1161152. 1296oo. 111~5o5. 1313139. 1963 5 113920, U81l71. 1135111. 98609. '13162 87339,. 88795. 93162. q.q6o'il. 1161152. 12'ilooo. 111!:1565. 13172?11, 1964 6 1 '\3920 i lll38b. 1135ll1. 98o09 0 93162 87339 88795, 93162. 986o'il. 1li:IIJ52. 129600 0 145565. 1313139. l'il6'i 7 I'U92o' 114386. 11351.11. 98609, 93162. 87339 88795. 93162. 98oo9. 11b'l52. 129600 1 1115565. 1313139. !9bb 8 1 'B92o: illlj86. 113541, 98609, 931b2 1:17339 88795. 93162. 9R6o9. 11b452. 129ooo. 145565. i313!l9 0 lqb1 9 113920 118•H1. 113541. 98b09. 931u2 A73H' 8879!:1. 93162. 98b09. 116452, 129&oo. 11155&5. 13172tl4. 1968 10 133920~ llll38b. 113541. 98609. 93162 8733'=11' 88795. 931b2, 98609 0 116452. 129bOO, 11J5565, 1313139. 1969 11 113920 ltiJ38b. 113541. 98609. 93162. 87339 88795. 93162. 98bo9. 1lb452. 129600. 145Sb5. 13131'!9. 1970 ~lEAN 113920 115500. 113541. 98o09. 93lb2 87339 88795. 93162. 9Bbo9. 1161JS2. 129bOO. 145565. 13111253, MAX I B92o; 1181171 113541 98o09, 9311>2, ll73H, 88795. 9l162, 9B6oq, llbll52 129bOO. lll55b5. !3112i?ll. MIN I 13920 1111386 1135111 98b09. 931b2 87339. 86795 93162, 98bo9. 11bll52, 129bOO, 145565. 1313139. I I '-- I ___) -l ...,I r -I ----, c=---~ r~-~--l r -=-~ ---, r--~, .. e_-~ r l ____ I I __ j I L_ '----- "' C HAK AC ~tA"lNA PROJECT OPERt.TIUtl STUDY llta79oo I H/H,H&CF.HECHTEL CIVIL&MINERALS INC.,SF. PROJECT ALASKA POwER AUTHORITY DATE. 32383 PAc,E:. 13 .... ALTERNATIVE Dl CHAKACHATNA TUNNEL, WITH ~ISH RELEASE:.S ENERGY DEFICIT Jtl HWH ~ YEAR JAN FEB MAR APR MAV JUNE JULY AUG SEPT OCT NOV OE:.C TOTYR CALYR 1 ' a • o. o. 0 0 0 o. o. 0. 0. o. 0. Q I t9b0 o, 2 o, o. 0. o. 0 o, o. o. o. 0. 0 1 0. o. I 9b 1 3 o, a. o. o. 0 0 o. o. 0. 0. 0. 0. o. 19b2 4 o, a. 0. llo 0 0 o. Oo a. o. 0. 0. 0 I 19b3 5 o, 0. o. o. 0 o, o. 0. 0. 0. 0 I 0. 0 0 19&4 b 0 0. 0. o. 0 0 o. a • 0. 0 o. 0 0 0. 19b5 7 o. 0. o. o. 0 0 o. o. o. o. o. o. 0 1 19bb 6 o. o. o. Oo 0 go 0. o. 01 o. n • 0. 0 I 1967 l:<o q 0 0 o. Oo 0 o. 01 0. 0. 0 1 0. 0. 1968 1 0 o, o. o. o. 0 o, o. o. 0. o. o. o. o. 1969 11 0 01 o. 0. 0 0 o. o. 0. 0. o. o. o. 1970 .... ~lEAN 0 ' 0 o. o. 0 0 o. o. 0. 0. o. 0 1 0. MAX ' o. 01 o. o. o' o. o. o. o. o. 01 0. "" o, MIN o. 0. o. o. o. or o. a • o. o. 0. 0. 0. ""' PROJECT AVERAG~ YI:AR I 2 J q 5 b 1 8 9 1 0 11 MEAN ~<lAX HlN lll87900t GE~JERATIUII JAN o, o, o, o, o, n, o, 0 n, 0 0 o' n, 0 I I ________.) IN Hw IN MONTHS UF SPILLS FEB HAR APR 0 0. o. 0 o. o. 0. 0 0 o. 0' 0' o. o. 0 o. o. 0. o. 0 o. o. 0. o. o. o. 0 o. 0, 0 o. o. o. o. 0 0 o. 0 0 o. 0 o. o. l-_' CHAKACHAHNA PROJECT OPERATION STUDY HIH,H&CF 1 BECHTEL CIVIL&MIN~RALS INC,,SFo ALASKA POWER AUTHORITY DATE 32363 PAGE I /J ALTERNATIVE Ds CHAKACHATNA TUNNEL, WITH FI 511 RELI:.ASES HAY JUNE JULY AUG SEPT OCT NOV DEC AVEYR CALVR 0 o, 221 300, I Ill o o. 0. 0. S'J, J9b0 0. 0 0 282. 300. 0. o. 0. (jq. I 9b I 0 0 0 227. 281). 0. 0. 0. ll2. 19b2 0 o, o. o. 282, o. 0. o, 23. !9b3 0 o, 0. 204. 214. o. 0. 0. 35. 196/J 0 0 o. o. 300. 0, 0. 0. ?'J. J9b5 o. 0 o. o. 262, 0. 0. 0. 22. !9bb 0 0 0 3oo. Joo. o. o. 0. so. 19&7 o. o' 0. 3oo. liiO. 0 0 0. 0. 37. !9bB 0. o' 0. o. 0. 0 o. o, 0. 1969 0 o' o. o, 0. o. 0. 0. 0. 1970 0 0 20. 11l7. 202, 0. 0. 0. 3 I • 0 o, 221. 300. 300, 0. 0. 0. ss. 0 0 0 o. o. o. o, 0. 0. ,--, c::--::-1 ,----c--=~ ,---.. r-:_=~ I I r r-~ I t __ --I I I I ---I ____) CHAKACHAMNA PROJECT OPERATION STUDY HIH.H&CF,BECHTtL CIVIL&MINEHALS INC1,SF1 PROJECT I IIAHOO I ALASKA POWER AUTH~RlTY DATE 32383 PArl 15 ALTERNATIVE Di CHAKACHATNA TUNNEL., WITH FISH RELEASFS SURPLUS EI~ERGY IN MIH YEAR JAU FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DI:.C TUTYR CALVR I r 0 o. 01 0 0 75LI27. 1.50038. 2&79. 0 1 0 1 0. 20811111, 19&0 o, 2 o, 0. o. o. o. o, o. 11b782. 117391. o. o. o. 2341711. 1961 .3 0 o. 0 o. o. 0 o. 7~918. 1031o6. o. o. o. l790EIII, 19b2 II o, 0. o. o. 0 o, o. o. 101131,8. o. 0. 0 1 lOII3bB. 19b3 5 0 0. o. 0. 0 0 o. ~85tU • 557211. a. a. o. 114265. J96LI 0 r 0. o. o. 0 o, o. o. 117391. o, o. a. 117391. 1965 o, 7 o, 0. a. o. a 0 o. o. 89921. o. o. o. 89921, !9b6 8 o, 0. o. o. 0 0 o. 130038, 117H1. 0 0 o. o. 2471130. 1967 9 o, 0. 0. o. 0 or o. 130038. 2535. 0~ a. () . 132573. 19b8 1 0 o, o. o. o. 0 o, o. o. o. a. 0. o. n. J9b9 11 0 0. o. o. 0 0 o. o. 0. a. 0. 0. o. 1910 HEAN o' 0. o. o. 0 o' b857. 58305. 64597, 0. 0. 0. 12ns9. HAX o, 0. o. 0. 0 o, 751127. 130038. 117391, 0. o. 0. 21171130, MIN 0 0. o. o. 0 o. o. o. o. 0. 0. 0. 0. '-' CHfiKACHA11NA PROJECT OPERATiml STUDY _. H/H,H&Cf,BECHTEL CIVIL&MINERALS INC 11 SF. PROJECT l£1879001 ALASKA POWER AUTHORITY DA H. 32383 PAGE: I b ALTERNATIVE Dl CHAKACHATNA TUNNEL, WITH FISH RELE.ASE.S REttAINltJG SPILLS IN CfS YE.AR JAN FEB MAR APR Mf\Y JUNE JULY AUG SEPT OCT NOV Of.C AVEYR CALYR 0 0 0 0. 0 0 o. 3£1'10. 0. 0. 0. 0. 287, 1960 2 0~ 0. 0 o. 0 o. o. o. 29£1. 0. 0 I 0. 25. 1961 3 0 0 o. o. 0 0 o. o. 0. 0. 0. 0. 0. 1962 q o, 0. 0 o. 0 o, o. o. o. o. 0. 0. o. lll63 5 o, 0. o. o. 0 o, o. o. 0. o. 0. 0. 0. 19btl b 0 0. o. 0. 0 0 o. o. Bo7. 0 o. o. 72. 1965 7 o, 0. o. 0. 0 0 o. o. o. 0. o. 0. 0. 19b6 8 o, o. 0 o. o. o, o. no a. 2&0. 0. 0. 0. b36. 19o7 q 0 0. o. o. 0 0 o. 1 71 q. 0. 0. 0. 0. 1113. 1968 10 . o. o. o. 0 o,. 0 0. o, 0 o. o. o. 19o9 o,. \ 11 0 o. o. o. 0 0 o. o. 0. 0 o. 0. 0. 1970 HE All 0 0. o. 0. 0 0 t). 1139. 129, o. o. 0. I Ob, MAX o, 0 0 0, 0 o. 0 73bB o Bb7. u. o. 0. b3b. MIN 0 o. 0 o. 0 0 o. o. 0. 0. o. 0. 0. r I __ I __ , __ I 1- PROJECT l4b79001 INSTALLED CAPACITY 330~00 Klol ANNUAL PLA~T FACTOR 45 OVEI\LIJAD FACTOR 00 PLANT EFFICIENCY • 85 0 FRICTIIJN LOSS COEFFICIENT 00001J2370 STARTER CAPACITY 50;) Go CFS TOLERAII.CE 01 0 PERCENT MONTHLY LOAD FACTORS 6'10 .,2G .610 6'1 0 7 00 BOO PIITIAL LAKE STORAGE l!'l775uo AC-FT MINIMUM LAKE STORAGE 33777"JO. AC-FT 1AXIMUM LAKE STORAGE 'tli77500 AC-FT J 920 CfiAKACIIAMNA PROJECT OPE RAT ION STUDY H/Holi&CfoBECHTEL CIVIL&MINERALS INC.,Sfo ALASKA POYER AUTHORITY r -- 1 I • DATE 32483 AL TERNATIH E I'CARTIIUR SHORT TUNNEL, \.liTH fiSH RELEASES 1. 0 0 0 • 920 .117 0 .780 .700 l_ --- PAGE ]-I -__) - PROJECT 14879~01 RESERVOIR STORAGE-ELEVATION-AREA AC-F T FEET /lCRE 0 76 c c 2r25 765 810 7'300. 770. 1300. 272"0 780 2&90 1110')!) 80'1 5670 241300 820 7320 397~30. f\4 0 82 70 572"t'Oo 86 a 928() 7td~Jo. 880 1 'J4 (10. CJSP~(IU CJC'l 11590. 12240v0 920 119f.:J. 1467000. 94 0. 12320 17170Cr>. 960 1265') 197301)0 981) 12'180 22360(0. 1COJ. 132110 25~41r0. 1!.'20. 135 20 2776"00. 1 04 0 1"'>740 3053000. 10&C 13'160 3335000 1 08 0 14170 362C'JOO 1100 14391). 391::00(). 1120. 1462J. 42180"0· 114 (I 1611"('. 425'J'J!!~ 1142 1678::: 4477500. 1155 17842 TAIUIATER-FLOII RELATIONSHIP F!:.ET CFS ;> 1 ~ , 21:) 100000 110NHILY MitJHoUM INSTREAf' FLOWS IN CFS 1094 1r94 1094 1094 1094 3f.5 MONTHLY DIVERSION RrauiREf'ENTS IN CF~ 0 J 0 0 0 CHAKACIIAMNA PROJECT OPFRATION STUDY ti/H,H&CFofiECIITEL CJVIL&f>IHJERALS INC ,SF. ALASKA POWER AUTHORITY DATE 3;>483 ALTERNATIVE E MCARTHUR SHORT TUNNEL• IIITH FISH RELEASES 365. 365 365 365 365. 1094 o. 0 o. 0 0. 0. 110NTIIL Y rlESERVO I R EVAPOKAT Iut. IN lNCHlS 0 Jo l __ ) ~~-_I 1-l o. I --__) 0 ~I-- 0 0. o. 0 (l 0. L __ t ( PAGE 2 -.... PROJECT 148f5t01 INFLOWS TO T~E LAKE IN CFS YEAR 1 2 3 4 5 6 7 p 9 1~ 11 12 13 1'1 1"> 16 17 18 10 2" 21 22 23 24 2'1 26 27 28 29 30 31 MEAl I MAY '1513. 2C"i5 3831 2G27. 3992 343'1 2193 2936 4393 2it 0 6 3120 3637 lf\61. 1265. 1811 1 !J:! Q 1286 1893. 2030 2996. 19lt8. 2265. ij:Jf:3 3it68 2131. 4215 it78it 5283 '1335 5387. 6776. 32Q1 6776 12f.5 JUNE 1072&. 8~72 1() 719 8204. 13247 90112 6826 7it75 14 R 17 9930 9459 61\37 798~ 7925 it735o 8093. 3490 RD72. 8761 1e'18 0 271 6789 12672 P22R 7 1157 6248 10649 8587. 191\64 7917 851'1. 8991'. JULY 152:>0. 1319it 13 09 "i 12575. 13355. 12091 12996 1'1601. 131'19 10163. 10388 11200 12R08. 131'1°. 1324 9 10700 11633 111303. lit931 13117 12478. 1Q360. 13 695 13'190 885'). 67fl1 1Q889. 83 04 13898 10146. 8958. 11928 1522 o. 6781 _j AUG 11615. 10'148. 8831. 9431. 10R08o 12£14&. 9983. 10235. 1 0 4 05. 8&91. 11731. 9337 10899 1 0411 12 2 08. 11798. 11929. 9974 15695. 11257 7297. 7986. 16680. 9263 7 8 09. 6159. 6802. 64 94. 11224. 7865. 9157. 10147. 16680 6159 I--~ CHAKACHAHNA PROJECT OPfRATION STUDY H/lloii&CFtBFCIITEL CIVIL&MINERALS INCotSF, ALASKA POWER AUTHOR lTY DATE 32'183 ALTERNATIVE E MCARTHUR SHORT TUNNELo Willi FISII RELEASES SEPT 6305. '1521 86)5. 3562. 45(15. 607'). 5068 594 0. 6910 3'1')2 3662 3145 6225 ">542 5847 4 24 6. 10802 66~8. 6191 27°3 27°3. 2734 ')07">. ')012. 2794 1'1850 ')117 4947. 6()'19 4513. 4572. 5177 101\02. 2n4. OCT :>61\9. 1761 3216. 2712. 2002. 2787. 1988. 2[)53. 2707. 1896. 1370. 1'13° 1586 11'l7. 2086. 124">. 2114. 1953. 2040. 976 3057. 1359 3181. 2396 :>527 3£i"i9 3136 3917. 3709. 3258 4471 2383 '1'171 976 NOV 802. 5b 0 o 842 865. 629. 75':io '195. 5H~. 793. 526. 654. 799. 843 863 930 9()9. 597 910 1215. 689. 1215. 742. 1090. (.,79. 740 9 0°. 814. 10 58. 922. 708. 1412. 828o 1412. 526 DEC 636. 532. 699 642. 550. 619. 532. 565. 562. 483. 50Ro -870. 696. 613 710. 662. 466. 313 571 612. 601. 460 736. 514 623. 53'1. 622 1055 700 7Plo 882. 621. 1055. 313 JAN 54 2. 495. 63'1. 523. 5:>7. 578 5Cilo 569 569 42&. 400. 877. 633. '198. 364 419. 388. 531. ')34. 485 497. 394. 581 495. 558 498. ')'14 1 0'14. 619 597. 762. 551 104 4. 364. FEll 488. 472. 495. 477. '172 507 475o 536. 51'Jo 468 307 '189. 5 '11 • 357 435 219. 336. 449. 510o 486. 5'14. 'I'll. ':i31. '192. 526. '185. 'l24. 773. 5~7. 562. 718. 4 91 773o 2l'Jo MAR 't'l3o 45[J. 4&7 477. 458 lif-6 4'10 505 480 4'tq 267 47C. 471 "'>15. 33? 337 35" 384. 467 r;or 55). 513 492. 480. 'jQl 4P5o 498. 1'.06 50"' 547 64 7 64 7 2&7 APR 541. 6 31. 510. 6 '11. 541 487 496 598 6 75 ':i26 3°3 346 470. 337 477 398 410. 88'1 63() 652 B 99 • 12 75 "79 '186 554 4 89 li25 (, ~& 55 A 713 810. 588 1275 337. PAGE AV'YR CALYR 4 5'18 3650 4 32 8 3 511 4?57 'I 071. ~5G'l 388~. 4&6"io 32"l2 3522. 3296. 37~3. 35~9. 359P 3405 365'). 3523. 4465 3'131. 3426. 294 3 4 94 0. 3759 2923 305'lo 3 75 0 3556 5327 3576. 3973. 37lH '1327 2923 19'10 1<l'il 1<>52 1953 10'i4 19~5 195& 19'17 19'i8 1°59 1%0 19~1 1962 1963 1964 1%"> }Of, f. 1%7 1968 196° 107r 1971 1°72 !07~ 1"7'1 1975 1976 1977 1978 1979 ..980 ., CfiAKACIIAHNA PROJECT OPERA TIO~I STUDY H/HoH&CFtBECHTEL CIVIL&MINfRALS INCotSFo PROJECT 14879001 ALASKA PO\IER AUTHORITY DATE 324 83 PAGE d ALTERNATIVE E MCARTHUR SHORT TUNNEL. WITH FISfl RELEASES PO\IER RELEASE IN CF S .. YEAR "lAY JUNE JULY AUG SEPT OCT NOV DEC JAN FER ~1A R APR AVE YR CALYR ., ' 1 1 P3't 1756 1712 lP 10 2004 2311. 2682 2954. 2740 2614 2360 2134. 2243 195( 2 196:?. 1879 1782 1813 2010 2315. 2693. 2970. 2756 2631 '?376. 21'19 2278 1951 " 3 1968. 1867 1 766. 11\19. 19'J5o 23 0 9. '?681. 2953. 2738. 2612. 2359. 21 ~3. 226 7 1552 .. " 1%1 1/lAO 1 78 7 0 lll18. (' 014 2311 2681. 2953. 2739. 2613 23f.Oo 2134 2271 1953 5 1Q52 1842. 1 7 3 7. 1013. 2 011 2314 ?690 296"i. 2752o 2626. 2H2 2145. 2268. 19'i4 F. 1966 18 74 1 781 1808 2 00 5 2~11o 2682. 2954 274 0. 2614 2%0 21"'15 226° 1955 .. 7 1°'12 11381> 17%. lll22 0 20Q8. 2~1'1 ?690. 2966. 2753. 262A 2374o 21'17 2279 1956 8 1970 1887 1788 1814 2005 231". 2689. 2965. 2751 2625 2370 2143. 2277 19"i7 9 1959. 1840 1 731 181'1. 2002 2311 2682 295'1 2 741 261'1. '?361 213"i 22€.2 195!\ 1 ~ 1960 li'F-.9 1781 le2~. 2014 231"io 2691. 2969 27%. 2631 2377 2150 2278 195Q 11 1971. 1879 1790 1820. 2014 2317 2696. 297'1. 2761. 2631l 231!'1 2157 228'1. 1960 12 1976. 1892. 18(9 18't2o 201F.. 2317. 2695. 2969. 2751. 26??. 2~68. 21'11. 2283 1961 .. 13 1970 1889 1 79"i 11119 20J't. 2316. ?6°3. 2967. 2752. 2625. 2371. 214'1 2279 1962 1'1 1975. 1898 1802 1826 2007. 2318 ?697 2973 2759 263lt 2381 21'1lt 228'1 1063 15 19f 2 1Q17 1830 1843 20 1 6 231'1 2687 2959. 27 116 2622 ?369 214"'1 2285 196'1 16 1CJ72. 1891 18115 1832. 2 012 2318. 2696 2972 2758. 26 33 2380 2153. 2285 196') 17 198lt 1927 18') 2o 1868. 1 98 7 2314. 2689 2965. 2753. 2629. 2376. 2149. 2291. 1%6 18 1977 H% 1811 18lt5 2003 ?~15. 26P9o 2964. 2 751. ?626. 2372. 2!46 2283 1967 ... 10 1973 1889 1783 1796. 2004. 23llt. 2686 2957. 27Lt4. 2618. 2365 21"'19. 2272 1968 20 1962. 11178 1785 1811 2 01 7. 2322. 270'1 2983. 2768 26lt3o 2387 21'19 2285 196CI 21 19116. lll"9 180C 1837 2017 2312 2679 29'19 2735 2610 2356 2130 2276 1970 ... 22 1957 1P81. 1803 18'14. 2 01 7 2321. 2700. 2979 2766. 26lt2o 2386 2157. 2288. 1<l71 23 1973 1862 1754 1793 2008 2~ 09 2680. 2950 2735 2609. 2356. 2130 2263 1972 24 19'i1 1!'64 1771. 1818. 20Jq 2~13. 2685. 2960. 27lt7o 2621. ?367. 2141. 227 0 19n 2'1 1 ')(, ll 1889 1813 1 f\60. ;> 02 0 2318. 260l 2956 27'12 26 25 2371 2144. 2285 1974 26 19'11 1&78 1 816. 1 P78 2029 2310. 2681 2953. 27lt 0 26H 2361. 2135. 228 0 1975 27 19Lt9 18Lt6 1 7'l 8 1826. 2C~8. 2309 2682. 2 954. 2HO. 2614 2.561. 21 "'15 2265 1976 28 19Lt7. 18'>0. 1776 1833 2£!09 2306 2680 2948. 272 8. 2598. 23Lt3. 2117 2251 1<l77 29 1931 1 7q4 1 71h 1811o 2C05o 2~07 2681 29'12. 273 7. 2611. 2357 2131. 2253 1978 3n 194 3. 1f''19. 1771 1823 2 011. 2309 268'?. 2954. 2HO. 2613. 2~59 2133 2265. 1979 .... 31 1938. 1836 1763. 1818. 2 010. 2303. 2678. 29Lt5. 2728. 26 00 23L!5. 2119 2257 198[) MEAtl 19~9 11;170 1 78 3 lll26. 2009 ?313 2688. 2961. 2747 26 21. 2367. 21Lt1. 2274. HAX 1986 1°27 1852 11.178. 2(129 ?322 "704. 2 983. 2768. 2643. 2387 21 '19 22Cil. I'IN lb3lto 17'>6. 1712 1793 19P 7 • 2303 2678. 29'1'1 2728 2598. 234~. 2117. 2243 l __ L__ l -~,or \ PROJECT 14879C01 SPILL Ill fFS Yf AR 1 2 3 4 ? 6 7 8 9 l'l 11 12 13 14 15 16 17 18 1q 2~ 21 22 ?3 21f 25 26 27 28 2Q 3C 31 MEAN 4A X MHJ MAY 1585 0. ~ . ~ 0 0. 0 0 0 0 0 c o. a 0 0. o. 0 0 0 c 0 (J 0 f) 0 0 0. 0 0 Q 0 0 0. 51 1 ')8 5 0 JUNE 7878 0 0 0 0. 0. 0. ~ 0 0 0 n 0 0 0. 0 c 0 c 0 0 0 a n 0 0 0 6592. 0 0. 467 7878 0 '~J JULY 12414 77'Jo 3074 0 7508 '104 n 731 8312, 0 o. Q 0 0 0 !l r. 0 1533 lf71 0 0 521° 2584. 0 a 321!:;. 0 11 088 80? 1436 1921 12'+14 n IIUG R7llo 7641. 5918 63 78. 79 01. 911flf 6028 7327 74 97 5238. 7217. 2861 f.q26 '18 03. 4180 55l!2. 575 ~8 09 12805. 8352 2567 11'66 13793 6351. 0 0 • 3PR2 o 2695. R319 494P 6245 5791 1379~ o. I __ ) CIIAKACHAI-'NA PROJECT OPERATION <iTUOY H/H,II&CF,DECIITEL CIVIL&MINERALS HlC oSF ALASKA POIJER AUTHORITY DATE 32483 ALTERNATIVE E MCARTIIUR SHORT TUNNEL, WITH FISit RELEASES SEPT 32il7 1417. 55'1 6 454 1'100. 2976. 1966 2 841. 3814 34 4 554 ~5o 3127 2441. 27'17 114 0 7721 3511 3 093. 0 0 !l. 1973 19~9. 0 107 20~5. 1844 ?960. 1'100 1468. 20£l0. 77?1 0. orr 13. 0. 542 o. 111. 0 0. 31. 0 o. 0 0 () 0 Q. 0 0 0. 0 72 0. 507. 0 0 38'1. 462. 12'16. 10~7. 504 1803. 220. 1803. () . NOV 0 0 o. 0 Co o. 0 0 0 0 0 0 o. o. 0 0 0 0 0 0 o. 0 o. 0 o. 0 0 0 !l 0 o. 0 0 o. flo 0 DEC 0 o. 0 0 0 0 0. 0 0 0. 0 0 o. 0 Oo 0. o. o. o. 0 0 o. 0 0 c. o. 0. o. 0. 0 0 0 0 o. JAN 0 0 0. o. 0 0. 0 0. o. 0 0 0 o. 0. IJ 0. o. 0 0. 0 0 o. 0 0 0. 0. 0. (). 0 0 • 0 0. 0. a FEO 0 0 0. 0 0. o. 0. c. 0 o. 0 0. o. a • o. 0. 0 0. 0 0 0 0 Q 0 0 0. 0. 0. c. 0. 0 0. 0 0 MAR o. Oo c 0 3 ~ o. 0 0. I) () ~ n o. 0 o. 0 n. !) ~. n 0 o. [l '1 0 o. c n ~ 0 o. 0 0 APR 0 0 n 0 0. 0 0 n • a Q 0. 0 o. 0. c 0 ~ 0. 0. 0. 0 0 (1 • c. c 0. 0. o. 0 0 0 0 0 PAGE 5 AVEYR CALYR 2 817. 819. 1257 572 1401 1 05 3. 666. 9u8 1638 '16'io 648 241 831.1 68 7. 577. 557 691. 52 7. 1453 735 22 0 1 'i 5 1791 Q04 0 '11 797 482. 2'100. 64 5 913 871 2817 o. 19'10 1951 1°5? 1953 19'14 1955 19"£: 1957 1958 1959 1960 1961 }O(,;> 1%3 196'1 }C6'i 1%6 196 7 191;8 1%9 1970 1"~71 1°72 1973 1974 197'1 1976 1977 1G78 1°7Q 19rc / io.l CIIAKACHAMNA PROJECT OPERATION STUDY H/lloii&CFoBECIITEL CIVIL&"'INERALS INc.,sr. PROJECT l't879il01 ALASKA PO!JER AUTHORITY DATF 32483 PAGE 6 ""' AL TERNATIVf E MCARTHUR SHORT TUNNfL, WITH FISH RELEASES FISH RELEASE IN CF S ._ YEAR MAY JUNf JULY AUG SEPT OCT NOV DEC JAN FEB MAR APR AVEYR CALYR 1 1G94 1C94 109 4. 1 c 94 1 Q04 365 36"io 365. 36"i. 365. %5 5 41 6A 3 19'i" 2 109 4 1 c 94. 10°4 1 .. 94. 1 J'J 4 365 365. 365 31',5 365. "'65 631. 691 1951 3 1094o 1 0 94 1094 1 0 94 1 oa 4 365. 365 "'i65. 365. 365. 36"i 510 681 19'i2 4 10"4. 1094 1094 1C94. 1 0"4. 365 365. 365. 365. 365. 36'io 641 69~ 1°5' 'i 1 09 4 1 ~ 94 1 0° 4 1 'j94 1004. 365 365 365. 365 365 365 541 68 3 1954 6 1G94 1094 1Q94 1 ~94. 1 094. 365. 365 365. ..,65 36"i ..,6" 487 679 19"i'i 7 1CC4 1 0 94 H94 1 n94 • 1 09 4 365 365 365. 365. 365. "'i65. 496 68 0 1°56 p 1'J"4. 1 094 1 09 4 1 ')94. 1 004 36"i 365 365 365 365 36"i 598 688 1957 ... 9 1~94 1 0 94 1 094 1 G 94 10"4 3&'i. 365 365. 365 36'5. "'i6"i. 6 t"i. 695 1°58 1 c 1!!0 4 1094 1 09 4. 1C94 1 QCI4 365 365. 365. 365 365 365 526 6fl2 1950 11 1094. 1~94 1 09 4 1 094 1 094 ..,65 %5 %5 %5 307 267 303 6'i8 1%C 12 10°4 1094 1 O'J 4 1 J 94. 1 0 CJ 'I 365 365. 365 36"i. 36'i 365 346 66 7. 1961 13 10"'1 1(!9'1. 1094. 1'JCilj 10'l4 365. 3€>5 365 36"i. "'i6'5 365. '170. 678 1962 1'1 1094 1094 109'l 1 ~ 94. 1 na 4 • 365 365 365. 3&5. 357. 315. ..,37 662 1°63 1'i 1 QCI4 o 1 094 1 ~9 'I 1 r 94 • 1C94o 36'i. ..,65. 365 • 36'l 365. 33~ 477 675 1964 16 10°4 1094 1094 1 :!94 1()94. 36"i 36"i. 365. 36'io 219 337 -.,a8 657 1965 17 11)9'1 1 0 °4 1 09 4 1C9'1 1 094 j65 365 365 3F>5 336 ... so 410. 669 1°66 1l< 1094. 1 c 94 1 094. 1 (\ 94. 10"'1. 365. 365 313. 365 365 365 880 707 1"67 10 1 0" 4 1094. 10°4 1 () 94 1(194 365. 365. 365. 365. 365 %5. 630. 691 10(.fl 2J 109lfo 1~0 lf 1 39lfo F9'1 1 ('194. 365. ..,65. 365 • 365. 365 365. 652 6"3 1CI6° 21 10°4. 1 ~94 1 oa 4 1 0 94 1 394 365. 36'1 36'1. 365. "'i65 36"i 899 713 197Q 22 1 OCJ4 • 1094 109lf 1 e 0 '1 1 O'J 'I 365 365. 365. 365. 365. 365. 1 0 9lf. 73 0. 1071 ;>3 1u9'1 1''94 1 O'J 4 1 ~ 94. 109lfo 365. "'if>'lo ..,65. 365. 365 ;16'1 4 79 678 1972 2lf 1n94 1 ~94. 1 ()'J 4 1 09'1. 1094. 365. 365. 365. 36'1 36"i. '65. 586 68 7 1973 25 1 GCI 4 U94 1 0 'J 4. 1 n94. 1 n94 36"i 365. 365o 365. 365. 365 554. 685 1 Q 7lf 26 109lf 1G94 1094 1()Qq 1 O'l4 • 365. 365. 365 365. 365. 36'1 4 fl9 679 197'1 27 1 O''l'l 1094 1 O'J lf 1 0 9lf 1 0°4 365 36'1 365. 365 365 36"i 625 690 1°76 21l 1C'3lfo 1C"lf 1 09'1. 1 r 9lf o 109'1. "'65 365. 365. 365 365 365 6 06 689 1977 20 1 0° 4 1"94 109lf 11°4 1 oq4 365 365 ,65 365. 36"i ..,6'1. '5"8 61'5 1"78 30 1094. 1 a 9 'I. 1094. 1 r 94. 1 OCI4 o 365 365 365. 365 365. %5 713. 6"8 1979 31 1C9lf 1 0 94. 1094 1&94 1 0°4 365. 365. 365. 365 365 365. 810. 706 1980 ~lEAN 1094 1 0 9lf 1 09lf. 1 0 9'1. 109'1. 365. 36"io 363. 365 357 358 ':ifl~ 6fl 5 MAX 1 [)04. 1G94o 1094. 1 fl94. 1094 365. 365. 365. ..,6"io "'i65. "'i6'1o 1 (J "4. 73 0 I" IN 1 09 'lo 1119lf 109'1 1, 91J. 1 091J. 3&5. 365. 313. 36lf. 219 267 337 657 , " " L ( PROJECT 14879001 ,NET EVAPORATION IN AC-FT YEAfl 1 ? 3 4 '1 6 7 8 q 1 (' 11 12 13 14 15 16 17 18 19 2v 21 22 23 24 25 ?6 27 ?8 ?9 3C 31 ME t.rJ MAX MIN 0 () 0 o. 0. 0 0 0. 0. o. 0 0 0. 0. 0. 0 0. o. 0. 0. 0 o. 0 c. 0. 0 0. c. 0. c 0 0 0 0 JUNf 'l c 0 0 0 0 0 0 0 0 0 0 0 0. ,., . o. 0 0 0. 0. a o. 0 • 0. 0 c (1. 0 0 0. 0. 0 0 0 ~I JULY 0 0 0 0 o. 0 0. 0 a 0 0 0 o. 0 o. 0 ~ 0 0 o. o. 0 0 0 0 o. o. 0 o. c 0 0 o. o. AUG 0. 0. 0 o. 0 • 0 0. 0. 0. o. o. o. o. o. o. o. 0 • o. 0. 0. (I • (). 0 0 0 0. 0 0 c 0 0 0 0. 0. 0 0 i; CHAKACHAMNA PROJECT OPERATION STUDY HIH.H&CF,AECIITEL CIVIL&MINERALS lNCotSFo ALASKA POWER AUTHORITY / DATE 321t83 ALTEkNATIVf E MCARTHUR SHORT TUNNELt WITII FlSit RELEASES SEPT 0 0 0 o. o. o. Oo 0 • o. 0 0. 0 0 0 0 0. Oo 0 0. o. 0. o. 0. 0 0 0 o. 0 0 o. 0 0 0 0 0 0 0 OCT 0 0 0. o. 0. 0. 0 o. 0 o. 0 0 0. 0. 0. o. 0 o. 0. 0 0 0. 0. 0 o. o. o. 0. 0. o. 0. 0 0 0. NOV o. 0. 0. 0 o. 0 0 0 0 o. 0 o. 3. o. o. 0 0 0 0 o. o. o. o. 0 o. Oo o. o. 0 o. 0 o. 0 0. DEC 0 o. o. o. o. o. 0. o. o. o. 0 o. o. o. o. o. 0 0 o. o. o. o. o. 0. o. 0 0 0. 0. 0 () 0 o. 0 o. 0 JAN 0 0. 0 o. 0. o. 0 0 0 o. o. 0 o. 0. Oo o. 0 0. 0. o. 0. 0. 0. 0 o. o. o. 0 0. 0. 0. 0 0 0 FEB o. 0 0 0. 0 • 0. o. o. :l. Oo 0. Oo 0 0 0 0 0. o. 0. () 0 0. o. 0 0. 0 0 0. o. 0 0 0 o. 0 0. 0. 0 HAR o. p. I' 0 0 c. 0 e 0 o. 0 0 n 0 ,., 0 "• c. 0 o. '] o. 0 o. 0 0 ~ 0 I) o. ~ 0 0 APR o. 0 0 0. 0 0 • 0. 0. 0 o. o. () 0 0 0 0. 0 0. 0. 0. 0 (I !) 0. 0. 0 0 0. 0. 0. 0 (1 0 0. PAGE 7 AVEYR CALYR o. lq~(l 0 1"'i1 0 1"'12 Q 1953 0 ]0 54 r. 195'\ o. 1°56 o. 19'17 0 1958 0 195Q 0 1Q6(l o. 1961 0 196? 0 1963 o. 1Q64 0. 196'1 0 1966 IJ 1967 0 1°66 0 196° o. 1q70 0 1971 0 197? 0 1973 o. 1Q74 0 1Q75 0 1976 ~. 1977 o. 1978 o. 197° o. 1980 0 o. 0 CIIAKACHAMNA PROJECT OPERATION STUDY ,/" """ H/H,It&CFoBECHTEL CIVIL&MINERALS INc •• sF. PROJECT 14879001 ALASKA POldER AUTIIOR ITY DATE 32483 PAGE 8 I... AL TEHNA Tl VF E MCARTHUR SHORT TUNNEL, WITH FISH RELEASES E.o.P. STORAGE IN ACRE-FT "' YEAR ~lAY JUNE JULY AUG SEPT OCT NOV DEC JAN FEB MAR APR AVEYR CALYR '"'" 1 44775 0 4477~00 4477500 1t477'i00o 4477!lOO 4 4 775 0 0. 434"'937. 41789fl2 4021409. 3Rfl3070. 3745820. 3618830 4221420 195~ 2 35'i7:'1l0 3A9C445 4477500 447750() 44775fl0. 4420969. 4272884. 4100551. 3939069. 3798899. 3658001. 3530102. 4"50058. 1951 3 3575%1 4037?06 4477500 4477500 4477500. 4477500. 4346329 4185300. 4(133252. 3890484 3751712. 36247A2 4112885. 1952 "" 4 35615b1 3872769. 4468818 4477500. '1'1775CO '1'177"iOO. '1347705. '1183166. 4024'170. 38B'i551 37'17341) 3628366 4095354 1953 5 367fl'il3 4292C86. 447750J 4477500 44 77"i00 4435A5'1 4291513. 4120550. 3%1305. 3821397 36812'i9 3553606 4105715 1C54 6 .. 576621. 391%57 4477500 4477'i00. 4477500. 4477500 4341126 4175085 4019690 1A82394 • 3743466 3616452. 4100041 1°55 7 3563406 379226A 441~665. '1477ooo 4477500. 4434989 421!8605 4116'189. 3955768. 3810939. 3670121 35'12351. 4045300 1956 8 3534480 3801875. 4477500 4477500 '14775()0 4'1"9004. '1291944. 4121916 3965287. 3829002. 369186 o. 356'1316. 4056015 19"i7 9 3f>466Q6. 43531109. 4477500. '1477500. '147751JO. 4477500. 434339A. 4173860 4017892. 3A8 0744 • 3743219 3616202. 4n ~48'i 19'iA 10 35A11l77 ~996422 4444'i"i3 4477500. '1477500 4429307. 4278737. 4103451. 3937736. 3 797327 3656348 3528432. 405°QC9o 195° 11 "531794. 3917746 4379145 4477500. 4477"i00 4396818, 4253567. '1079480. 39118'19. 3760115. 361349Co 34A5129e 4023679. 1960 12 3520C05, 37'19135 '12">9863. 4477500 '1477500. 4401080. '12665'16 '1115051. 3971393. 3Alf4210. 3705083 3577675 lj030920. 1961 13 3504':165· 38112458. 4'11233() 4'177!:>00 '1'177500. 4410160. 4278352. '11162'17. 3963506. 3827'1 79 3688216 356063"i 4043279 1962 14 3449689 3743212 4373660 '1477500. lf477"i00 '138613~ '12'i5?71. '1087709. 39262li8o 37799'19. 36 3356 8 3505'111· 4C07910l7 1963 1'i '427032. 3529642 4164483 4'177500. 4'1 775C 0 4ljlj]Qlf;>. '1314758. lf15lf012o 3985169. ~838383 3692693 3565157 4~r"iE14. 196'1 -16 3489171 3793096 4272757. 4477500. '1'177500 '13A9C.98o '126101!! '1096569. 3930333. 378lf082. 3637751 3509638 4009876. 1965 17 3 .. QOlj76 3'127392 39615C9 4lt7750!J lflf775ro 4lflf277lo lj 296588 lil20li95. 39526'18 38'16661. 3660597 3532726· 3962988 1966 18 346"3P7 3762715. 4217(,20 4'i77'100o '14 77"i'J 0 4'132827 43 G!i262o H23035. 396'1069. 3822909 3671\212. 3'l"i0527o 4022707. 1967 ..... 19 34A6753 3830!:>84 '1477500 4477500 4'177500 4'138201. 432893'1. '1159771. 4001'159. 38'l9198 3720061 3592806. '10708"i5 1968 2J 358914 5. 3876930 4477500. 447750C '1458"ifl0 '~"'53391 4211779 li0'135'i1o 3880715 37'10634 3602136. 3'173645 4015'159 196° 21 3404il28 3777592 4366893 4477500 4458580 4'177500 436fl638 420181lf 40U 746 3914523. 3771 oLt a. 364'1315 407'1515. 1C7() 22 "5595992 3A22934 4281846 4477"iOO. '1455056. '1373491. 4235260. 4 0579'18. 3889667. "7'17179 36 09563 3491978 4G03201 1971 23 35532'17 4131lfl6o 4477500 lflf77500. '1477500. lj 4 7 75 0 0 '1361162 '1202599. 4047738 39)7217 3770185 3643444. 412 7 ::>51 1972 24 3&69439. 3983032 4477500. 41f77'iOO. 4477'1QO. 4lf60189. lf319090 '1146270. 3985373 31!'16862 370838'1. 3581010 4u94346 1973 25 352~781 3790004 4155425. 4 4"i3961 4'134923 442'1319 '1287507. 4121009. 3963688. 3826825 3689'111 3561842. 4C1947lf 19 74 26 36331°A 3828135 40661~1 '126211!1 4'177500 4'177500 '1350336. '117/l901. '1018605. 3880068 37'12288 3615262 '1044170. 197"> 27 H?22°2 '1181POlfo 4477"i00 '14775 00 '1'177"iQO 4'177500 '134465'1 '11788'12. '1021391. 38!!0166. 37'13191 3616174. 41331li3 1976 28 37"i4042o 4:J8981Ao 4423913 lf477500o lflf77500 4477500. lf359248. 422039'1. lf09'14illfe 3972776. 38'13551. 3717551 41"i9016o 1977 29 3A595C3o '1'177500 4477500 '1'177500 4477510. 'llf77'iOO. 435111lfo lj19020'1. lf036918o 391)1486 3765lf4 0 3(38650 4177575 1978 30 37P3157 't079l'IC 4'177500 4477500 44775'10 4477'i00 '133831'1 '1177313. '1023122 388A93lto 3755092 3628197 lf131C39 1979 31 ~858'116 4190670 '1'177~00 '147750() '14775CO '1477500 4380lf21. lt231118. 4087815. 3958563. 3831711. "7C5592o 4179525. 19PO ~1EAN 3611904 3943038. 4381455 446979) '1'17'1 182 4442521 lf310129 41'13925. 3986'1'13. 38'17033 3708091. ~581058 4fl74964 - Mid( '1477500 '147750~ 4lf77500 4lf77ouo 4477500 '1'177500 lf380421 4?31118 '109lflf0'1. 3972776 "'84"551 3717551 42?1 112 0 IHN 3399'176 3'127392 3961 "i09 '1262118 '143'1923. 4353391. '1211779. 4043551. 3880715. 374063'1. 3602136. 3473645 3962988 I , __ -0 l-1~ --=-~ ---' ., ~~'' I' ~-:::::= "" CIIAKACHAMNA PROJECT OPERATION STUDY 11/II,II&CF tBECIITEL C I VI L&MINERALS INC.,SFo PROJECT 1487"001 ALASKA POYER AUTIIORITY DATE 324 03 PAGE 9 t:l ALTERNATIVE E MCARTHUR SIIORT TUNNEL, WITH FISH RELEASES EoOoPo LAKE LEVEL IN FEET el YEAR MAY JUNE JULY AUG SfPT OCT NOV DEC JAN FEB MAR APR AVEYR CALYR d 1 1155 1155 1155. 1155. 11 'i 50 1155 114 7. 1137. 11:>7. 1118. 110"· 11 c 0. 1139. ..19 50 2 1096 1119 11'i5 1155. 11 'i 5. 1152. 11'13 1132. 1122. 1112. 1H"'io 1 0 94 1128 1951 J 3 1097 1128 1155 1155. 11'i5. 115'io 1148. 1138. 1128 1119. 1H9 110n. 1132. 1952 4 1C96 1117. 11 <; 5. 1155. 1155. 1155. lllf B. 1138. 1127. 111 B. 1109. 1100. 1131 1953 5 llulf lllf4o 11 'i 'io 1155. 11 "5. 1153 1144 1134 1123 111'1. 110'1 1095 1132. 1954 d 6 10°7. 1122 1155. ll'i5 1155. 1155. 1147. 1137 1127 1118 1109o 11C0o 1U1 1"5'1 7 1096 1112 1151 1155 11'15. 1153 ll'llf 11~3. 1123 1113 11 C3 1095 1128 1"56 8 1C 0 4 1113 11'15 1155. 1155. 1153 1144 1134. 1124. 111'1 1105. 1096. 1128 1957 rtJ 9 1102 11'18 11'i5 1155. 1155. 1155 111f7 1137. 1127 1118 1108. 11 00. 11 ~4. 1958 10 1097. 1126 1153 1155 11 '15 0 1152. 114'1. 1133 11 ;:>2 1112. 110 ~ 1 0 94. 112 9 1959 11 1'i91f. 1121 11'19 1155. 1155. 1150 1142 1131 1120 1110. 1100 l!l91 112 6. 196C ~ 12 1r"3 1109. 1143 1155. 11'15 1151 1143 1133. 1124 1115 1106 1C97 112 7 1%1 13 10°2. 1113 11., 1 11 'i5 11'15. 1151 1141fo 11~~. 1123 1111f. 11Q5 1 0 96. 112 8. 1962 1'1 1088 1108 114° 1155 11'i5o 1150. 1142 1132. 1121. 1111. 1101 1092 1125 1"63 ~ 1'i l'J86. 1~94. 1137 11'i5o 1155 ll'i3 1146. 11%. 11::>5 1115. 1105 1096 1125 196'1 16 1091 1112 1143 1155. 1155. 1150. 11'13. 1132. 1121. 1111. 1101. 1C92o 112 6 1°65 0 17 1 J85. 1086. 1123 1155 1155 1153 1145 1134. 1123 1113. 1103. 1!l94 112 2. 1966 18 1089 1110 1140 1155 11':15 1152 1145 1134. 1124 1114. 1104 10°5 112 6 1"!07 1" 1091 1115 1155 1155. 11'i5 1153. 1147. 1136. 1126 1116. 1107 1098 112 9 1°68 lb 20 109!1. 1118. 1155. 1155. 115lto 11lt8o 11lt0o 1129. 1118. 11 oa. 1099. 1 0 90 112 6 196° 21 1 08 5 1111 11lt 9. 1155 1154 1155 1149. 1139. 1129. 1120 1110. 11 02. 1130 1970 22 1!l"8 1114 114lt. 11'15. 1154 1149 1141. 1130 1119 1109 109°. 1091 11::>5 1"71 23 1 .195. 1134 11'i'i 115'i. 11'15 1155. 11 lf8o 1139. 1129 1120 111 0. 11 02 1133 1972 d 2lf 1103. 1125 1155 1155 11'35. 115lt. 111f6 1135. 1125 1116. 1106. 1C97 1131 1"73 25 1093 ~ 112 1136 115lto 1153. 11'12 114lt 113lt. 11::>3. 1114. 1105 1 ()96 112 6. 1974 2f> 1101. 1114 113 0 1143. ll"'i 115'1 1148. 1137. 1127 1118 11 o8. 1100 1128 197'i d 27 11u7o 1138 1155 1155. 11'i5 1155. 11lt7. 1137. 112 7. 1118. 1108. 1103. 113lfo 1976 28 11,9. 1132 0 1152 1155 115 5. 1155 lllt8o 11lf0o 1132. 1124 111 t:. 1107 1135 1977 29 1117 1155 115 5o 1155. 11!:J5. 115'i 1148 1131lo 11211. 1119 1110. 1101. 1136 1"78 d 3(' 1111 11 31 11 ')5. 1155 115 5 1155 114 7. 1137. 1127. 1119. 1109. Ill' 1 113lt. 1"7" 31 1116 1138 11'\'i 11'i5o 1155. 1155 1149 11lt1o 1132 1123. 1115 1106. 1137. 1981' tJ 11E AN 1099 1122 114 9 1155 ll'i'i 1153 114!:1 1135 1125. 1116 1106 1097 113 0 MAX 1155. 11'i5 1155 1155 11'15. 1155 1149. 1141. 1132. 1124 0 1115. 11 07 113 9 d MIN 1085. 1CB6o 112 3. 11lt3. 1153. 11lt8o 114 0 1129. 1118 1100. 109 9 1090 112 2. .It) ,..) >1!111 ~ ~ ,i:J \ PROJECT 14879001 IJATER BALANCE YEAR 2 3 4 5 6 7 8 9 10 11 12 13 1 4 1'i 16 17 18 19 20 21 22 23 24 2'i 26 27 28 29 31 31 ~lEAN f~AX MIN ,_ f1A Y 0 (1 o. 0 0. 0 0 0 'l c. c 0 t 0 0 :J. :J (l • 0 c. (I • :J 0. 0 0 0 0 0 0 0 G 0 0 0 JUNf 0 , G 0. 0. 0 0 0 o. :J 0 0. 0 0. c D c • 0 0 !) • 0 0 0 s. c 0 0 .. 0 0. 0 0 JULY 0 'I D :J 11 J I) "· 0 o. n , ') a n 0 '1, o. 0 0 0 :J 0 :J 0 0 0 n 0 :J 0 IJ n AUG 0. 0 0 0 0 0 0 0 o. 0 0 a IJ • a 0 o. 0 0 • 0 a. 0 o. 0 0. 0. 0 a :J 0. a. o. 0. 0 o. CIIAKACHAMNA PROJfCT OPfRATION STUDY H/ll,ll&CF.BECitTEL CIVJL&MINERALS INCooSFo ALASKA POIJER AUTHORITY DATE 32483 ALTERNATIVE E MCARTHUR SHORT TU~JNELt IJITH FISH RELEASES SEPT 0. 0. I) 0. 0 0 a. a. 0. o. a 0 a. 0 0 0 0 0. 0 o. 0 0 0 () 0 0 0 o. 0 0 0 0 • 0 0 OCT 0 0. 0. 0 I). o. 0 0. 0. 0. () 0. 0. I) 0. 0. 0 0. 0 0. 0 o. 0. 0 0 0. 0. 0. (' o. 0. 0 0. 0 NOV c. o. a. 0 0 '1. 0 o. o. 0 :J. 0 'lo 0 0 o. o. 0 0 0 0 o. 0. 0 0 0 0 0. o. 0 0 0 0 o. DEC 0. 0 0. o. 0 0. o. 0. o. 0 0. :J 0. 0. o. o. o. 0. 0. o. 0. o. 0. 0 0 0. o. 0. 0 0 0. 0 n • 0. JAN 0. 0. 0. o. 0. 0. 0 0. 0. o. 0 0 0. 0 o. o. 0. 0. 0 0. o. o. (). 0 o. o. 0. o. 0 0. o. 0. o. 0 FEB o. 0. 0 o. 0. o. o. o. 0. 0 0. 0 0 0 0. 0. 0 0. 0 o. o. 0 0. c. o. 0. 0 o. 0 0 o. 0 (). ~IAR 0 ( :). :J n. 0 '1 '1 (' o. 0 n 0 0 o. n :J 0 £l. 0 0 o. 0 () 0 o. 0 0 0 0 o. 0 c 0 APR • c 0. o. 0 • 0. c 0. 0 0. o. 0. i) • (' 0 0 0. 0 0 0. 0. 0 c r • 0 0 0 0 () . 0. G 0 0 0. 0 0 PAGE 10 AVEYR CALYR 0 19"0 o. 1Q51 a 1952 0 1953 0 1°54 o. l9'i5 a 1956 o. 1°57 a 1°'i8 a. 195° a. 1°€-0 0 lq61 0 1962 !) 1q63 0 }Q64 (). 1965 a 1966 "· 1967 "· 1968 0 1°6q a 197a c. 1971 0 1972 o. 1973 a 1974 (' 1975 0. 1 q 76 o. 1977 o. 1°78 0 1979 0 198a 0 0. a - PROJECT 148790:l1 POYER IN "'IJ YEAR 1 2 3 4 5 6 7 p 9 1: 11 12 13 14 1') 16 17 18 }Cl 20 21 22 23 24 25 26 n 28 2<1 3~ 31 MEAN o1AX JAIN MAY 124 124. 124 124 124 124. 124. 124 124 124. 1?4. 12 4. 124 124 124 124 12". 124 124 124. 124 124 124 124. 124 1?4. 1?4 124. 1?4 124 124. 124 124. 124 JUN[ 12u 120 1?0 120 120 120. 12C 12() 120 120 120 120. 120 12u 1?0 120 12(). 120. 1?0 12G 120 120 1?0 12J 12u 12u 12 0. 120 12:i 120. 120 120 120 12G ,, J JULY 118 111l. 1lll 118. 118 118 118. 118 11.13 118 118 llP 118 118 118 118 1113. 1Ul 118 118 118 11fl. 118 118 118 118 11R 118 118 118 118 111' 118 11 A AUG 124 124 1 ?4. 124. 124. 124. 124. 1 ?4. 124 124 1?4. 124. 124. 124. 124 1 ?4 124. 124 124 124. 124. 124. 1 24. 12l!. 124 124 124 124 12l! 12l! 12l!o 124 124 124. ) __ / CHAKArHAMNA PROJECT OPERATION ~TUDY 11/litllfCFoBECIITEL CIVIL&MINERALS INC.oSF. ALASKA POWER AUTHORITY ,- -.1 I DATE 32l!83 ALTERNATIVE E MCARTHUR SHORT TUNNELo lollTII FJSIJ RELEASES SEPT 136 1% 1% 136. 136. 13Go 1"36. 1% 136. U6 136. 136. U6 136 1% 1>:6. 136. 1% 136 136. 136. 1% 136 136 1% 136. 136 136 136. 136. 136. 1~6 1% OCT 155 155. 155. 155. 155. 155 155o 155. 155 155. 15') 1'l5. 155 155. 155o 155 15'lo 155 155 155. 155 155. 155 1'l5. ~155 1'55 1!:i5 155. 155. 155 155. 155. 155 155 NOV 178. 178 17Ao 178. 178. 178. 178. 178. 178 178. 178. 178. 1/8. 178. 17&. 178 178o 178 178 178. 178. 178. 178. 178. 178 178. 171!. 178. 178 178 178. 178. 178 178. DEC 19l!. 194 1<14. 19l!. 194. 191j 19l!o 194. 194. 194. 19'1. 1<llto 1<14 194. 194 194 194. 194 194 0 194. 194. 194. 194. 194. 194. 191J 194. 191J. 194. 19l!. 191J. 191Jo 19l!. 194 JAN 178. 178 178. 178 11 a. 178 178. 178 178 178 178 178. 178 178. 178. 178. 17 8. 17P 178. 178. 178 178. 178. 178 178 178 178. 178. 178 178. 178. 178 178 178. FEB 16<1 169 169 169. 169. 169. 169 169 169. 169. 169. 16<1. 169. 169. 169. 169. 169. 16<1 169. 11'.9. 169. 169 169. 16<l 169 169 169. 169. 16<1. 169o 169 169. 169 169 MAR 151 151 l"i 1 • 151. 15!. 1'i1o 151 151 151 1'i1. 151 151 151. 151 151 151. 1'i1 151. 151 151 1')1 1'l1 151 151. 151 151 l'i 1o 151. 151 I'll I'll 151. 1'll 1'll APR 136 136 136 136. 136 136 1% 1 'i6. 13&. 136. 136 1 'i6 0 l'i6 136 136. 136 136 136. 136. 136. 136 1'i6o 13&. 136. 136 l'i6. 136. 136 136 136. 136 136. 1% 136 ---1 _, PAGE 11 AVEYR CALYR 14 9. 149. 14 Cl. 1l! 9. 14 9. 149. 149. 14 9. 14 9 14 9 149 149. 14 9. 14 9. 149. 1l! 9 14 9 14 9 14 9. 149. 149 14 9 14 9 14 9 14<l 14 9 14 9. 149 14 9 14 Cl 149 14 9 14 9 14 9 19!:>0 1Q51 1<l'J? 1953 195l! 1°55 1956 1957 l<l5r 1959 1960 1%1 1°62 1963 1964 196'> 1966 1967 1968 196<1 197C 1°71 1972 1973 1974 197'l 1976 1977 1978 197° 198!! / (b rl CHAKACHAMNA PROJECT OPERATION STUDY fQ HI H eii&CF, BECIHEL CIVIL& MINERALS INC .sF. PROJECT 141'79001 ALASKA POIJER AUTIIORITY DATE 32483 PAGE 12 q , ALTERNATIVf E MCAR H'UR SHORT TUNNELt WITH FISII RELEASES ENERGY IN MIJH c " YEAR f1A Y JUf'.E JULY AUG S[PT OCT NOV DEC JAN FEB MAR APR TOTYR CALYR r 1 92230. e' 'l r, f fl7907 92 30 97623 115288 128304. 144110. 132581. 113242. 11240'; 9762~ 130COOP 1950 2 92230 &6%6 87907 92<'3!1. 976?3. 11'i2fl8. 128304 144110. 132581. 113242 112405 97623. 1300008 1951 3 Cl22~0. 86466 87907 92230. 97623 11'i288 1211304 144110. 132581 117287 1124 05 Cl7623 1304052 r 1"'i2 4 92230 86'166. 87907 92230. 97623. 115288. 12£1 304. 144110. 1325EI1o 11321!2. 1124 05. 976?3. 1300008. 1953 'i Cl2230 86466 El7907 92230 97623 1152fl8 128304. 144110o 132581· 11324?. 112405 97623. 130('008. 1 C) '54 ( 6 92230 86466. 87907 92230. 97623 11"288 1283G4o 144110. 132581. 113242 1124 C5o 97623 130<1008 1955 7 92230. 864fo6. 87907 92230 97623 115? 8 8 1t>R3(14. 144110. 132581 117287· 112'+05 Cl7623o 1304 052. 19'i6 [l 92230. 86466 87907 Cl2?3C 97623 115288 12830'1 144110. 132'i81. 113242. 11240'i 976?~. 1300008 1Cl'i7 ("' 9 9223C 86466. A79G 7. 92230. 971'.?3. 115?8A· 1?A~C4 144110o n?5111· 11~242. 112405 Cl762~ no o oa a 1Cl58 1n 9?23:! 86466 87907 9?<'.30. 97623 115? 8 8 12A304 144110. 132581 113242. 1124 05 97623. 13000~8. 1959 11 9::>?30 86466 87907 92230. 97623 115288 128304. 144110. U2581o 117287 112405 "7623 1 'I ()4 O'i2 196C f'J 12 92230 fl6466. 87907. 92230. 976?~. 11'5288. 128304. 144110. 132581. 113242. 112'10'io 976?3 1~00008. 1961 13 92?30 86466 87907 92230 97623 11!:!288. 1211304. 144110. 132581 113242. 1124~'i 9762'1. 1300008. 1962 14 92?30 86466 P.79~7 92230 97623 115288. 128304 14lf110. 132581. 113242 112405. 97623. 130~008 1963 15 Q2?30 A6466 117907 9213u 97623 ll'i21lR. 12ll30lj 1'11!110 132'58lo 117287. 112lj05 97623 1304 052 19 64 r, 16 92230. 86466. P79'J7 92230. 97623. 115288. 128304. 1'14110. 132'581 113242. 11240'5. 97623. 1'00008 196'i 17 92230 86466 87907 9223u Cl7623 115288. 12830lj. 144110. 132581. 113242. 1124 05 97623. noooo8. 1966 18 92230 A6466 87907 92230. 97623 115288. 128304 144110. U2581 113242. 112405 97623 1300008. 1967 ("I 1Q 92?30 86466 P7907 92230 97623 11'i288 12830'1 144110 132581 117287. 1124 05 97623. 13Cij052 1968 20 92230 f\6466 87907 922"0 9 7 6? ~. 115288 128304 144110 1~2'ifl1 113242 112405 9 7623 1300008. 1969 21 Cl22.30 86lj66 87907 92?30. 97623 1152 8 8 12830lj 1'1'1110. 132581 113242 112405 97623 1300008 1970 r;. 22 9;>230 86466. 87907 92230. Cl7623 1152 8 8 12P.304 14Ljll0. 132581. 113242. 112405. Cl7623. 1300008 1q71 23 92230 86466 87907 0 22~0. 9762~. ll'i288. 12P~04o 1'1'+110o 132"ifl1o 1172P7. 1124U5. 976?3 1304052 1972 24 92230 86466 87907 0 22 30 97623. 115288. 12A304e 144110. 132581 113242 112405 97623 1300008 1°73 ('; 25 Cl;:>230 86466 87907 9?;>30 97623. 115288. 126304. 144110. 132581 113242 112lj05 9 7623 13000J8. 1974 26 92230. 86466 El7907 92?~0. Q7623 11'1288. 12b3G4 144110. 132581. 113242 11240'i 'l7623 1300008 197'i 27 "2230 86466 879u7 9?230 97623 11'i281l 12PH4 14'1110. 13?'ill1 11 7?87. 1124(15. 97623. 1304 052 1976 \") 28 92?3 0 864F,6 87907 92230 976?3. 11528A. 12fl304 144110. 132581. 11~242. 112405 97623. 1300008 1977 29 9?2~0. P6466 87907 9?230 "76?3 11528A 1283Qlj 144110. 132581. 11 ~2 4 2 112405 9 7623 13000(18 19 78 31 0 2230 86466 87907 92230 97623 115288. 121130'1. 1'14110. 13?'581. 113242. 11240'i. 97623. 1300008 1979 (". .. 31 "2230 86'166. 87907. 92230 97623 115288. 128304. 14H10 132581 117287. 1124('5 97623 1304052. 1980 MEM' 922~0. 86lj66. 87907 92;i30 97623 11'i288o 128304. 14lj111J. 13?5fl1o 114286. 112405. 976?3 1301051 c MAX "2230 86466 87907 "22 30 9762 3 11'i?88. 128304. 1lj4110o 132581 117287 112405 97623 110" 052 r;, MIN 92230 86466 87907 922JO 97623. 115288. 128.304. 144110. 1325fl1o 113242. 1124(15. 97623. 13000'18 ,.. ,.., ("-_. JO>_, 1'.), ---, PROJECT 14fl79G01 ENERGY DEFICIT I~ M~H YEAR 1 2 3 4 lj 6 7 8 0 1J 11 12 13 14 15 16 17 10 19 2C 21 <:2 23 21f 2"i 26 27 28 33 31 MEAN "1AX ~~~ N MAY c. (l 0. 0. 0. 0 D n • 0 o. 0 0 o. 0. 0 c. o. 0 0 o. o. ~. 0. 0. o. Q. 0. r • 0 0 o. 0 0. 0 0. JUNE 0. 0 • 9 c r . . 0 a 0 ll (I 0 0 0 0 ll. 0 0. " 0 0 0 0 n 0 o. [l • 0 Q 0 a 0 0 0. JULY o. n '1. 0 c 0 c. 0 n 0 J l' n 0 0 0 'I o. 0. c. o. !l. o. o. 0 9. n Q 0 r. :J. D 3 (' AUG o. 0. 0. 0. 0 o. 0. o. 0 o. 0 o. 0 0 o. o. 0. 0. 0 o. o. 0 0 0 0. 0. 0. 0. o. o. 0. 0 0. 0 I L ~ = rHAKACHAHNA PROJECT OPERATION STUDY 11/ll,lf&CF,BECHTEL CIVJL&MINERALS INC oSF ALASKA POYER AUTHORITY ~ I ) ~- DATE 32411.5 ALTERNATIVE l MCARlltUR SHORT TUNNELo IIITtl FISH RELEASES SEPT o. o. 0. o. 0. o. o. 0 c. o. 0 a I) a 0. o. 0 0. o. c 0. 'l 0 0 0. o. o. 0 0. o. 0 0. I) • o. OCT o. o. 0. 0. 0. (.l. 0. 0. {) 0 0 0 0. D • 0 0 o. 0. o. o. o. 0. c () . 0 0. o. 0 0. o. o. o. D 0 • o. NOV o. a. 0. 0 0 0 0 o. o. 0 o. o. 0. 0 o. o. o. 0. o. o. 0 o. o. o. o. D o. o. o. 0 o. o. 0 o. ore o. o. 0. o. 0. o. o. o. 0. 0. o. o. o. 0. o. 0. o. 0. o. 0. o. o. 0. o. o. o. 0 o. o. o. o. o. 0. 0. JAN 0. 0. D. o. 0 Oo 0. o. o. o. o. 0. 0 0 0 o. 0 0. 0. 0 0 o. o. o. 0. 0. 0. 0. o. 0 0 0 0 0. 0. 0. fEB o. 0. 0 Do 0 • o. c. 0 0 0 0 c. c. o. o. o. 0. 0. 0 0. o. 0. 0. 0 0. o. 0. 0. 0 0. 0 0. c 0 0 MAR o. o. n o. o. !l. 0 P. a 0 J. 0 ~. 0. 0 o. o. n o. 0 n. o. o. 0 ~ o. I) a. IJ "· o. 'I APR 0 0. 0. n • Q o. 0 ... 0 o. ~. c 0. n 0 0. a c 0. 0. J. D n 0. o. 0. n • 0. 0 0. a. 0. 0 0 PAGE" TOTYR CALYR o. 1q5o' o. 1951 0 1952 0 1953 0 1°54 0. 19'i'5 0. 19 56 0 1957 0. 19 58 o. 195° 0 1°60 0 1%1 o. 1962 o. 1963 0 1 °6'1 0 0 1965 o. 1966 0 1967 0 1968 0 196Q c. 1970 0 1971 0 1972 0 1073 0 1074 0 1975 o. 1976 "· 1977 0 1°78 0 1979 0 1980 I) 0. 0 ... v AVERAGE GEl [RATIO~' IN I'IJ W t10NTJIS OF SPILLS YEAR 1 2 4 5 6 7 8 9 1 n 11 12 13 14 1'1 16 17 18 19 20 21 22 23 24 25 26 2 T 28 29 30 31 MEAN MAX "liN MAY 231 0 0. o. ,.. 0 0. D • 0 o. 0 (). c G 0 0 0 0 0. 0 0 0. n • !! 0 0 0. 0 c c 0 7 231 o. JU~IE 33U o. 0 • 0 0 0 0 n 0 c 0 0 0 Q 0 • 0 lj 0. (I. 0 0 II • 0. J c 0 c • 0 330 0 0 21 330. !J • JULY 33 Q 17'?. 326 o. 3311 14 7 n 1 7:J 33~ o. Oo 0 r -· fl J flo n t'24 152o 0 0 3~0 294. o. 0 33" 0 ~ ~ ~ 174 216 124 331) ,.. AUG '130. 3 30. 330. 330. 330. 330. 330. 3 ~f). 330. 330. ~30 ~17. 330 330 :na 330. 165o 314. '130 330 297 2 'iG • 33(1 330. 0 0 330. 3 05. 3~~ 330 330 298. 330. 0. CltAKACHAMIIIA PROJECT OPERATION STUDY lt/lloH&CFoDECIHEL CIVILUIINERALS HIC oSF ALASKA POWER AUTHORITY DATE 32483 ALTEPNATIVE E MCAPTHUR SIIORT TUNNEL, WITH FISol RELEASES SEPT 3-S 0 2~1 330. 166. 230 330 267 326 33!!. 1~9. 173 1~Ao 330o 299. 3? 0. 212. 33 0 3~0. 330 o. o. 0. 268 264 o. 144. 271'\ 259. 3~0 230 234 231. 3~0 0 ,_. OCT 156 o. 191. 157. 0 163. 0 0. 157 o. o. 0. 0 0 0 0 0 0 0. 'l. 160 o. 189 0 0 181. 186. 2.38. 224 194 275. 80. 27'5o 0. NOV o. 0 0. o. o. 0 0 0 o. o. 0 0 0. 0. o. !! o. 0 0 0 0 o. o. 0 o. 0 o. o. o. 0 0 o. o. o. DEC 0. 0. Do o. 0 o. o. 0. o. o. o. o. 0. 0. o. 0. 0 0. o. o. 0 0. 0. () 0 0. 0. 0. o. 0 0. o. o. o. -, JAN 0 0. 0. 0 0 0 o. 0 o. 0 o. 0. 0 0 0 o. 0 0 o. o. 0 0 0 0 0 0 0 0 o. 0. 0 Oo 0 o. 0. 0 FEB 0 0. (). 0. 0. 0 0 0 0 Oo 0 () () 0 () . 0 0 0. 0 0 0. o. 0 0. 0 0 0 0. 0. a 0. 0 o. 0 0. MAR IJ 0 0 ('. 'l 0 o. a o. 3. 0 0 o. J. 0 o. n 0 o. (1. 0 n () "· o. I). J 0 ) APR 0. 0. 0. 0 () 0 0 () 0 ~ 0. () n • o. 0. a. Q 0 0 0 0. 0 !) o. 0 0. a. 0 0. a. 0 0 a • o. 0 PAGE 14 AVEYR CALYR 142 61. 98. 54. 74 81 50. 69. 96. 41 42 18 "\5 52 54 45. 41 54 74 40. 31! 21 q3 74 0 0 27. 93a 67. 129. 77 86 63 1li 2 0 19"0 1951 1952 1953 1954 19'i'i 1956 1957 1958 195q 1Q6r 1%1 1962 1963 1964 1565 191i6 1967 1968 1969 1970 1971 1972 1973 1974 197"\ 1976 1977 1978 1979 198C ,, PROJECT 1487°001 SURPLUS ENERGY lN Mllli YEAR 1 2 3 4 'i 6 7 8 9 10 11 12 13 14 1'1 H: 17 18 10 20 21 22 23 24 25 26 27 28 20 3n 31 MEAN MAX MIN MAY 793'i6o 0. 0 !l. o. 0 (I 0 c o. o. o. o. 0. 0. o. 0 0. 0 o. o. ~. o. 0. 0. o. 0. 0. 0 ~. 0. JUNE 151134 0 0. c. () . 0 0 0 c • !l. a o. 0 0. 0 () 0. 0. 0 0 0 0 0 0 • c 0 0. 0 () . 151134 ~ 0 2560. 9751 79356 151134 0 0 JULY 157613 40191. 155008 157613. 21737 0 38512 157613 0 () () 0. 0 o. 0 0 785C5 25295 J c 157613. 130615 rr o. 157613 0 157613 41 23 6 72645 49'381 15761~ 0 1 I i_...---y CIIAKACHAMNA PROJECT OPERATION STUDY H/H,H&Cf,[3ECIITEL CIVIL&MINERALS INC oSF. ALASKA POIJER AUTHORITY DATE 3241!3 ALTERNATIVE E MCART~UR SIIORT TUNNEL, IJITII FISII RELEASES AUG 153290. 153290. 153290 153290. l'i32°0 o 15~290. 153:>90 153290 153290. 153290. 15329(). 11t"'>566. 153290. 153290. 15~290. 15~290. 30253. 141059. 153293. 153290. 128560. 93760. 153?90. 153290. 0. () . 153?0 0. 135L36o 15329(). ]532D0 1'13290. srPT 139977. 611462· 139977. 21985. 67686. 139977. 94971. 137231. 139977. 16654. 2~832 1776 139q77 117943. 132724. 5513ltG 139977 0 l-.,0 977o 13°977o 0. o. 0 0 95310 92257 0. 5914. 96861. 891L7o 13°977o 6fl074 70933 135416. 81279. 153?90. 139977. 0. 0. OCT 72..,. 0 27030. 187lo 0 • 5615. Oo 0 1621. 0. () 0 0 0. o. Do 0 0. 0. 0 3732 0. 25283 o. 0. 19192 23036 6 2023 'i1639. 29126. 89677 10986. 89677. 0. NOV 0 0. o. o. o. 0 o. o. Go o. o. o. 0 0 () o. o. o. o. o. o. 0 0 o. 0 0 0 o. o. 0 0. 0 o. 0 DEC 0. o. 0. o. 0. o. 0 o. 0. Oo 0. ~ . o. o. a. o. 0. Oo 0. o. !lo o. 0. o. o. o. 0 0. (l • 0 0. 0. o. o. JAN o. 0 0 o. 0. 0 0. 0. o. o. 0. 0. o. 0 0 0 • o. 0. o. o. 0. 0. 0. o. 0. 0. 0 0. 0. 0. 0 0. 0. 0. FEB 0. o. 0. o. 0 0 0. c. Q. 0. 0. 0 0. ~. D. 0 0 0. a • 0. 0. o. 0 c. o. o. 0. 0 • 0. o. 0. 0 0. (I. MAR o. ,. 0 o. o. 0. 0 'l. 0 rJ. 0 n. o. o. 'l n 9 0 o. !) o. c o. ~. o. a o. 0 o. D 0 0 0 o. PAGE 15 APR TOTYR CALYR o. 682G93. o. 261942. o. 4753~5 ~. 177146. Oo 378'i89o o. 320619 o. 248261 0 12°0'3 0 452502 o. 169944. c. 180121. 0 145342. 0 293257. o. 271233· o. 28601'1 o. 21184?4 o. 170231 o. 281036. o. 371773. o. 178'185. o. 132293 o. 93760 0 431496 o. 376162. 9. 0. o. 25107. o. 430!l01. o. 21!6166 0 653654. o. 291726 0 386546. 0 289973 ~ 682093 0. 0. 195(! 1951 1952 1953 1954 1955 1956 1957 19'18 1959 1960 1961 1962 1963 1964 196'i 1966 1967 1968 1969 1970 1971 1972 1973 197lf 197'i 1976 1977 1978 197° 1980 r~ I PROJECT 14879C01 REMAINING SPILLS IN CFS YEAR 1 2 ~ 4 5 6 7 8 9 1 0 11 12 13 1'1 1'i 16 17 18 29 20 21 22 23 2'+ ?5 26 n 2P 2q 30 31 MEAN ~AX MIN 11A Y o. (l 0 J () 0 :J n 0 Q 0 'I 0 • oJ 0 0 0. G • 0 0. c. a o. 0 0 0. 0 () . o. ~ n • 0 :J 0 JUNF '17'12. ') 0 c il • 0 0 0 0 0 J 0 0 0 0 • 0 () 0 0 0 0 () . c c 3 () 0 0 3'19'1 0. 0 266 '17'12 JULY 9239 () 0 '1353 o. 0 G 5151 o. c o. 0 0 ('I 0 (\ n () o. '1 0 2 08 ~. 0 '1 0 81. D 7917 0 930. 9239 0 AUG 5629 '1562. ?fl'l!: 3 ~ Glf • '1822 6c60o 2959 '12'19. '1'119 2169. '11'15 o. 3A 53 • 2736. 1126. 2'182. o. 0. 9709 5271. o. o. 1 0 6 9'1. 3277. o. 0 816 0 5238 1 A 79 • 3171 3078 1069'1 0 CHAKACHAMNA PROJECT OPERATION STUDY lfllltlf&CF,BECHTEL CIVIL&MINERALS INC.,SFo ALASKA POWFR AUTHORITY DATE 32'185 ALTERNATIVE E MCARlHUR SHORT TUNNEL, WITH FISH RELEASES SfPT 3('8. 0 2638. 0 0 78. 0 0 913 0 • 0 IJ. 228. 0. (! 0. '1805 611 19'1. o. 0 0 n, 0 () 0 0 0 62 0 0 317 'lbv5 D OCT I .. 0. 0 0. 0. 0 0. o. 0 0 0 o. o. 0. 0 o. o. 0 0 0 • o. o. 0. 0 0 0 0 0. 0 o. 0 G 0 0. 0 0 NOV o. o. 0. o. 0 o. 0 o. o. 0. 0 0 o. c. o. 0 0 0 0 o. o. o. o. o. o. 0 0 0 0 0 0 0 0 !l DEC 0. 0. () 0. Q. I) 0 0. 0. 0 0 0. o. 0 0. o. 0 0 o. 0 0 • o. 0 Jo () 0 0. 0 0 0. 0. 0. o. 0 0. 0. JAN 0 0 o. 0. o. o. o. 0. 0 0 • 0 0. o. !l. 0. 0 o. o. o. o. 0 o. o. 0 0 0 o. o. 0 0 0. 0. o. 0. 0 0 r - I .. FEB 0 c. 0 0. 0. 0. 0 o. 0 0 0. 0 0 0 0 0 0. 0 0. 0 0 0. 0. 0. o. o. 0 0 0 0. 0. 0 0 0 MAR o. 0 0 o. o. n. " n 0 0 o. 'I o. :J. o. o. o. o. () o. o. o. o. 0 n c (\ a. 1'\ 0. 0 o. o. 0 APR 0. () . n • 0 0. 0. 0 0 0 Oo J 0 0 0. n 0 0 0. G • n :J 0 0. 0 • 0 0 0. 0 0 0 0. 0 0 0 PAGE 16 AVEYR CALYR 165 0 0 380. lf57. 275. 755 512 247 35'1 874 181 3lf 5 0 3lf I) 228. 9'1. 237. '100. 51 • 825 '139 !l 0. 1 06 50 273. 0 o. 7'i 0 1393 157 2611. 383. 166 0 0 1950 1951 1952 1953 195'1 1955 1956 1957 1956 195Q 196" 1961 1962 1q63 196'1 lq6'i 1q66 1967 1968 1969 1Q7Q 1971 197:' 1973 197<1 1q7'i 1976 1977 1978 1979 1980 t .. '~ APPENDIX TO SECTION 8.0 / ESTIMATE SUMMARIES \ ('---~-_...........__ ~ -...._ ......._ ""- ) I ~) )__ _7' I --:> ( --<-_--~ l_ ~ f -) ~-__:-_) - CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL ESTIMATE SUMMARiES-SHEET 1 OF 2 ~·--, ,~1 \ -----l ESTIMATED COSTS iN THOUSANDS OF DOLLARS Al TEIRNATiVES A LAND AND lAND RiGHTS Not mcluded 0 POWER PLANT STRUCTURE AND IMPROVEMENTS Valve Chambe~ 5,800 Underground Powe~ House 26 200 Bus Gallenes 200 Transformer Gallery 4600 Valve Chamber and Transformer 400 Gallery -Access Tunnel P H Access T1.11nnel 13,500 Cable Way 800 --51300 RESEk,IOIR, DAM AND WATERWAYS Ret3r•ou 100 Dnta' ~~Structure 10,400 ln\ak~o Gate Shaft 13,200 F1sn Facllltlez - D1ke & Spel!way - Access Tunnel -At Intake 21,600 -At Surge Chamber, No 3 15,600 -At Mila 3 6 No 1 0 -At Male 7 5 No 2 0 Power Tunnel 626 800 Surge Chamber -Upper 12 900 Penstock -lncimed Sect1on ,8 000 -Honzo1111tal Sectaon and Elbow 6700 -Wye Branches tc Valve Chamber ,3200 -8etwee1111 Valve Chamber 8r Power House 800 Draft Tuba Tunnei1 1,900 Surge Chamber -Yaeirace 2,400 Tailrace Tunnel and Structure 10,300 Taalrace Channel 900 Rnter Trammg Works 500 Mesceilaneoui Mechanict.ll and Elactl'lcal 7,100 --753,400 A 8 -McArthur development h1gh level tunnel excevatad by dnlhng end blastmg C D -Chacackatne valley development excavated by dnllmg and blastmg E -Me Arthur development low level tunnel excavated by bormg mach me B Not mcluded 0 5,500 25,200 200 4,300 400 13,500 800 -49900 100 9300 12400 - - 19100 5,900 0 0 580400 11000 16 500 6,000 '81,900 600 1,700 2400 9600 700 500 6,100 --694,200 c D E Not IIJllcluded 0 Not mcluded 0 Not mc!uded 5600 5,600 5500 26,200 26 200 25 200 200 200 200 4300 4300 4300 400 400 400 13501!]) 13,500 13,500 800 800 800 -51,000 -51,000 ---49,900 100 100 100 10,400 10,400 9300 13 200 13,20Q 17,600 --85,400 --9,100 21600 21,600 0 8,90(]1 8,900 5,900 20800 20800 0 14500 14,500 0 "12,50(]1 712,500 447,800 12 900 12 900 18,900 15 400 15 400 0 6700 6,700 6000 12100 12100 11900 800 800 600 1,900 1900 1,700 2400 2400 2400 10300 10 300 9600 900 900 700 500 500 500 5,700 5,700 6,100 --871,600 --871 600 --1533,600 CHAIKACHAMNA HVDROEliECTR!C PROJECT CONCEPTUAl ESTIMATE SUMMARIES-SHEET 2 Of 2 -J Al TEIRNATiVES ESTiMATED COSTS !N THOUSANDS OF DOILLAIRS A TUIRIBHiiiiES AND GENERATORS 67,900 ACCESSORY EILIECTIFUCAIL EQUiiPMEi\!1" 11,200 M!SCIEILILANEOUS POWIER PLANT !EQUiPMENT 8 6001 SW!1l'CHYARID STRilJICTUIRES 3,600 SWITCHYARIO IEQ!miPMIENT 13 800 COMM SUPV COINTIROILIEQUIIPMEN"'J' 1600 TRANSPORT ATBON IF ACB Uli'"IIES Pert 4,600 Aurport 2000 Acces! allld Constructaoro Reads 59600 --66200 TRANSMiSSiON! U~E & CABLIE CROSSING 63,200 TOTAL SPECDFBC CONSTIIU.IICTDONI COST AT 1,040 8001 .UANIUIARY 19821PRiCE !LEVElS ENGINEERING & CONSTRIUICTHON MANAGEMENT 124,900 SI!JBTOTAl 1165 700 COII\ITINGIEI\!CV@ 20% 233100 ESCAILA'TIONI Not lncl IIMTEIRIEST DURING CONST @ 3% IPEIR ANNUM 111900 OWNER'S COSTS Not Dncl AllOWANCE FOIR FISH! PASSAGE FACIUTiES - TOTAl PIROJIECT COST AT , 510 700 JANUARY, 19821PROCIE !LEVELS USE 1500 OCIO A B -McArthur development h1gh level tunnel excavated by dnlhng and blastmg C D -Chacackatna valley development excavated by dnlhng and blastmg E -Me Arthur development low level tunnel excavated by bonng mach me 4600 2 000 59600 -- IB c II) 57 9001 54500 54500 9500 S,OOOI 9,000 7 300 6,90(!1 16 900 3600 3,600 3,600 12 500 12,100 12100 , 600 1,600 1,6001 4,600 4,600 2,0010 2,000 44,100 44,100 66200 50,700 50,700 63 200 56,500 56,5001 965 900 1,1H 500 1,117 500 H5 9001 ,34100 134,100 , 081 8001 1,251 600 ~ 251,600 216 400 250 3001 250,300 Not !1111c8 Not l1111c! Not ~nci 104,100 11n 40o 101,400 Not lnci Notlm:l 1\!ot Inc! 50000 -50 000 1452 300 1,603,300 1,653,300 1,450 000 1600 000 1650 000 ( -~ I-~I 4,600 2000 59,600 IE 57,900 9,500 7,300 3600 12 500 1,600 66,200 63,200 905 300 108,700 1,014 000 203 000 Not Drn:l 97,400 Not Unci Ulirnder Reservoer !tem 1,314,400 1,314,000 ALTERNATIVE A ESTIMATED COST HAJ/APD PAEPAAED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE A NO DESCRIPTION I .y POWER PLANT STRUCTURE & IMPR( Valve Chamber Excavation & Supports Concrete & Reinf Steel I I --__, CJ r-' L __ __! ESTIMATE SUMMARY CHAKACHAMNA UYDRQELECTRIC PRQJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT COSTS VEMENTS 10,500 CY 270 6.520 CY 410 AMOUNT 2,835,000 2,673,200 Struc Steel & Mise Meta s 52 TON 1,800 93,600 Round-Off (1,800) Underground Powerhouse Dewatering LS 4,100,000 Excavation & Supports 64,000 CY 155 9,920,000 Drilling-Percus & Rotarv 15,000 LF 30 450,000 Concrete & Reinf Steel 14,200 CY 630 8,946,000 Struc Steel & Mise Metals 330 TON 5,300 1,749,000 Architectural LS 1,000,000 Round-Off 35,000 Bus Galleries Between Power house & Transformer Vaults -Excavation & Supports 200 CY 825 165 ,000 Concrete 120 CY 21)0 34,800 . Round Off 200 HlsCF CSE 623 13-801 14879-001 JOB NO NOV 1981 DATE SHEET 1 OF 15 TOTALS REMARKS 5,600,000 Ent1re Undereround Comnlex 2" -3"0 26,200,000 200,000 -r r--~~ l __ ~ _j '---~ HAJ/ APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHIECKED BV DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 2 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE A PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS ~ TrsmAformer Gallerv & Tunne 8 Excavation & Supports 13,000 CY 280 3,640,000 Concrete & Reinf Steel 900 CY 460 414,000 Struc Steel & Mise Metals 130 TON 3,800 494,000 Round Off 52,000 4,600,000 Valve Chamber & Transformet Gallery-Access Tunnels Excavation & Supports 1.500 CY 250 375 .ooo Concrete 60 CY 290 17.400 Round-Off 7'.600 400 000 Powerhouse Access Tunnel Porte! Excav & Protection 56.000 CY 10 560.000 Portal Cone & Reinf Steel 1,000 CY 570 570.000 Tunnel Excav & Supports 24.000 CY 300 7 200.000 Tunnel Concrete 900 CY 290 261.000 Tunnel Mise Metals 30 TON 11 000 330 000 Subsurface Exploration Mobilization LS 1 500 000 Exploratory Adit 1.000 LF 1.800 1 800.000 Core drilling 5.000 LF 140 700.000 Helicopter Service LS 600 000 Round-Off (21 .000) 13_._500 .. 000 HBsCF CSE 623 13-801 I r--~1 L --J r--, ( --J r- 1 ___ j t __ J '----- ESTIMATE SUMMARY HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 3 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE A PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS C..Rhl~ Wav C.nn"-r~t:~ & R~inf St:~~l 1 000 CY 700 700 000 MiS!: Metals & Cable Suo 26 TON 5.100 132.600 Pnrt: P.Rn~lA Rnund-Off (32.600) 800,000 TnTAT. PnWF.R PT.ANT STRI lUlU!. ~lillV~'.fl:i 51,300.000 HS.CF CSE 623 (3-801 I --~, ! ___ J ......__.-_ _) HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE A NO DESCRIPTION LJLK DAM & WATF.RtJI\.YS ~ ....... Llat-...... T ... u .. l R .. l'nT"tHn11 Tni"<al.r .. St.ruct-HTII> Si t"A Rvnlnr<atinn Mnhi1i~"'rinn r.n...... Tlri 11 i no .HPlirnnt"~T SE>rvir~ 'l'tm~l "'~""'" ~ C!. 't"A 'l'unnal f'.nnf' 1.. R .. inf' St"P .. J ... lr .. -T.,n (FinJ>l Rn11ntll Pl.,,...a ~ T .. mn r.nnf' n-fu-fno r.rPW Rnnnd-Off In take Gate Shaf.t. Shaft Ex£'.av .& Stmnnrt:& Mass Sur.f"'""' FYI'::t~ Cancre_t-~ t. RE>inf Stt~>E>l Misc. Metal.s . r.., t-.. 1'1 & Hni It" Rnund...,.Q£f_ ·HIICF CSE 623 13-801 r - I (-:-_J l~ ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS LS LS 150 000 5,000 LF 80 400 000 LS_ 150 .. 000 12,000 CY 470 5 640 000 100 CY 350 35 000 LS 3,000,000 600 .CY 700 420,000 60 I DAYS_ ~o .. ooo 600,000 5,000 10 000 CY 360 3 600 000 50 000 lc:v 30 1 500 000 5,700 lc:v 890 5,073 000 244 i'l'ON ti.2 500 3 ,050 ... 000 (23 .000) r--\ I TOTALS 100,000 10 400 000 13 200 000 L = 26' _14879 001 JOB NO NOV. 1981 DATE SHEET 4 OF 15 REMARKS I L HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE A NO DESCRIPTION Access Tunnel at Intake Portal Excav & Protectio Tunnel Excav & Supports Tunnel Cone & Reinf Stee Round-Off Access Tunnel at Sur2e Cham Portal Excav & Protectio Tunnel Excav & Suooorts Tunnel Cone & Reinf Stee Grout:fnll Cnnt~ct & Pressu Wateri2ht Bulkhead & Fram Round-Off Power Tunnel Excavation & Suooorts Concrete Grnutin~ C.nnt~ct & Pressu Round-Off HIIICF CSE 623 13-801 J I L ESTIMATE SUMMARY (- l ; l 14879-001 JOB NO NOV 1981 CHAKACHAMNA HYDROELECTRIC PROJECT DATE er ~e !-e PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 6,000 CY 50 300.000 72,000 CY 295 21.240.000 200 CY 500 100.000 (40,000) 6.000 CY 35 210,000 17 000 CY 295 5,015,000 2.000 CY 420 840,000 2.500 CF 58 145,000 27 TON 13,800 372,600 17.400 53.400 LF 8,800 469,920,000 410,000 CY 334 136,940,000 370.000 CF 54 19,980,000 (40,000) SHEET 5 OF 15 TOTALS REMARKS 21,600,000 6,600,000 626,800,000 - HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYI'E OF ESTIMATE ALTERNATIVE A NO DESCRIPTION Sur2e l'hn-'-~r -Unn~E!r p..,.,.n••.,t-inn Ft. ~nnnnrt-a Concr~E!t:e & Reinf ~t-PPl F.art"hwnrlc:A Ft. li'Pnl'ina Round-Off PenAt-nrk-lnl'l inP<l ~a ... t-inn F.Xl"SliVAt"inn Ft. ~nnnnrt-a Concrete & Reinf Steel Groutin2 Contact & Pres Round-Off Penstock-Horizontal Sectic ..,....,.,.n .. 'ltion & SuoDorts Concrete S Reinf St~E!el Groutin2 -Contact Round-Off H&CF CSE 623 13-801 I l_ ESTIMATE SUMMMV CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 35 500 ~ 200 7.100.000 6.100 ~ 880 5,368.000 15 000 ~ 27 405,000 27.000 27.000 CY 280 7,560,000 12.000 CY 845 10,140,000 !sure 6 200 CF 52 322,400 (22.400) n & Elbow 14.000 CY 310 4,340,000 6,000 CY 365 2,190,000 3_,000 CF 50 150,000 20,000 ~r l -r TOTALS 12,900,000 18,000,000 6,700,000 14879-001 JOB NO NOV. 1981 DATE SHEET 6 OF 15 REMARKS He11port, Storage, Work Area , __ ) l-_~_j (-j I ___ ] ~-I I j ~--1 HAJ/APD ES11MATE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAl. CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 7 OF 15 TYPE OF ESTIMATE ALTERNATIVE A ALASKA POWER AUTHORITY PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS P~~>nat-nl'lt-'L1v4'1 Rr::anl'h<>a rn V::; ltve C.h<~mh~r Excavation & Sunnorts 10 000 CY 440 4 400 000 Concrete & Reinf Steel 7,200 CY 608 4.377 600 Steel Liner 850 TON 5 000 4 250 000 Groutin2-Contact 3,000 CY 50 150.000 Round-Off 22.400 13,200,000 Penstock Between Valve Chan her & Powerhoufe Excavation & Supports 1,000 CY 440 440,000 Concrete & Backfill 600 CY 550 330.000 Round-Off 30.000 800,000 Draft Tube Tunnels Rock Bolts & Grout 19,000 LF 27 513,000 Concrete & Reinf Steel 3,300 CY 425 1,402,500 Round-Off (15.500) 1,900,000 Sur2e Chamber -Tailrace Excavation & Sunnorts 5,000 CY 480 2 400.000 HS.CF CSE 523 (3-801 ( L ___ I r---\ r--- I HAJ/APD PREPARED BY MF CHECICED BY CONCEPTUAl. TYPE OF ESTIMATE ALTERNATIVE A NO DESCRIPTION .Tailrace Tunnel & StructurEs l'.nff~rdam & n~wat~r{n~ Portal Excav. & Protecticn Concrete & R~inf Steel Walkwav Bridtze Stoolo!Zs & Hoists Tunn~l Exrs:~v. & SnnnnrtA PlUJZ Excavation Round-Off Tailrace r.h:;mnP1 r.h:~~nnPl Excavation River Tr11ininll Works River Bed Deepening Mech & Elec r -- L J CHAKACHAMNA HYDROEI.ECTRTC PRO.IECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS LS 2,000,000 2 000 CY 65 130,000 1 200 CY 600 720,000 LS 65,000 81 TON 8,500 688,500 25_..000 C'{ 260 6,5UU,UUU 4_,000 CY 50 200,000 (3 ,500) 100_,000 CY 9 50,000 CY 10 LS TOTAL RESERVOIR, DAM AND Wi TERWAYS HACF CSE 623 13-801 -' I TOTALS 10 ~._300 ~._000 900,000 500,000 7.100 000 753,400,000 l_ l _) 14879-001 JOB NO NOV 1981 DATE SHEET 8 OF 15 REMARKS I I ----' HAJ/APD PREPARED BY MF CHECkED IBIY I -~J I '-- CONCEPTUAL l"YPE OF ES'fiMA'fE ALTERNATIVE A NO DESCRU'TION 'l'urbines & Generators Turbines Generators Round-Off Accessorv Electrical EauiDI Eauioment -Mise Power Plant Eouioment Crane Bri<il!e Other Power Plant Equin Switchvard Structures Earthworks Concrete & Reinf Steel ent Struc Steel & Mise Meta s Round-Off -i&CF CSE 623 I:WWI I I ~...... __ J c=-~ CHAKACHAMNA HYDROEI.ECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 4 EA 9.930.00~ 39,720,000 4 LA 7,050,00 0 28,200,000 (20.000 LS 1 EA 1 100.000 LS 7.500.000 15,000 CY 25 375.000 3,800 CY 640 2.432 000 225 TON 3,500 787.500 5.500 I -.J TOTALS 67,900,000 ll,ZOO,uuu 8.600.000 3,600,000 ~-I ) 14879-001 JOB NO NOV 1981 DATE SHEET 9 OF 15 REMARKS l-~- JJAJ/APD PREPARED BY CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE A NO DESCRIPTION Switchvard Eauinment - Transformers 105 MVA Unit &.Line Breakers Switches & Li2htn Arrestc rs 230 KV Cables Controls & Metrv2 Eauin Rnund Off Crnnmun1.cat1on and Suov r.nnt.rol Eouin -. H&CF CSE 623 13-801 --I CHAKACHAMNA HYDROELECTRIC PROJECT QUANTITY 5 7 30 18,000 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNIT UNIT AMOUNT COSTS EA :U52,000 5,760,000 EA 206,000 1,442,000 EA 37.00( 1,110,000 LF 140 2,520,000 LS 3,000,UUU (32 ,OOU) LS - l -j 14879-001 JOB NO NOV. 1981 DATE SHEET 10 OF 15 TOTALS REMARKS l.J,I:SUU,UUU .L,ouu,uuu I ,-~\ I ·~-- (~ _ ___, HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 11 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE A PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS ~SPORTATION FACILITIES Port Facilities Causeway 19.600 CY 80 1,568,000 Trestle Piles 50 TON ~1,300 565,000 L -150 LF, !612 , t -~· Trestle Struct Steel 110 TON 3,500 385,000 Trestle Reinf Cone 150 CY 700 105,000 Facilities -Allowance LS 2,01)0,000 Round-Off _(23 ,000) 4,600,000 Airport Earthwork 54,500 CY 16 '0/'L,UUU Culverts 1,000 LF 65 65,000 Subbase & Base 55,000 CY 14 770 ,ouo Building -Allowance LS 300,000 Round-Off (7 000) 2,000,000 - i&CF CSE 523 I:WWI -I I HAJ/APD PRIEPA!ItiED BY MF CHECK lED BY CONCEPTUAL TYPIE OF IESTIMAVIE -~ I ..._---- ~-- 1 ALTERNATIVE A NO DESCRIIPTIOi\1 ,,.,. .. .,., I. Construction Rn;u1l~; Mil"' 0+00 t"n 1R+OO F.aTt:hfol'nrk f'onlv.,.rt"A Rr"fldo~A ~"~bas~ & Bas~ n,,.ll!"d Rai ~ llon<>ir Exist.inJP: RnA.t ~nnw F'"nC'~R Round.-Off u.ft ,..,. 1 A.Mln tn -:ti\+On Ji'A'!r"t"L Culverts SubhAR~ I. RaAP- r.uard Rail R~'>nAi1" RxiRtfm~ Rnad Snnw F~nc~s Round-Off MH,. 1'i.+On tn 1Q+OO F.arthwnrk Culv~rts Rriclol'> c .. hh:a<> F. RaAP- r.nard Rail Snnw FPnceR lllnun.-1. -Off HG!CIF CSE 623 13-801 r----r --1 1 I-"-- 14879-001 JOB NO NOV 1981 DATE CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 12 OF 15 ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS 175 000 CY 6 60 1,155,000 1 500 LF 65 97,500 36 11i CMP 1 400 SF 150 210,000 85,400 CY 15 1,281,000 1 200 lF 25 30,000 95,000 LF 10 950,000 5.000 LF 35 175,000 1~500 3,900,000 1.465 000 CY 6 60 9,669,000 3 600 LF 80 288,000 48"~ CMP 165 000 CY 15 2,475,000 13 .ooo LF 25 325,000 16 000 LF 10 160,000 1,000 LF 35 35,000 482000 13 ;oo-o ;non 445.000 CY 8 30 3,693,500 1,000 LF 80 80,000 48"~ CMP 9 000 SF 150 1,350,000 38.000 CY 15 570,000 10.000 LF 27 270,000 2,000 LF 35 /U,UUU (33 2 500) 6,000.000 l __ __ _) HAJ/APD PREPARED SY MF CHIECCC:ED BY CONCEPTUAL TYI'E OIF ESTIMATE ALTERNATIVE A ~0 DESCRIPTION _Walkwo To Gate Shaft Earthwork Guard Rail Bridge Rip rap Round-Off Access Road to MacArthur Earthwork Culverts Bridae Improvements Subbass & Base Guard Rail Snow Fences lRo_Ul!ld-Of f A.rc•a:>A.A. _Roa,_d _to Tailrace Es.rthwork Culverts Subbase & Base Guard Rail Round-Off HEIICF CSE 623 13-601 CHAKACHAMNA HYDROELECTRIC PROJECT QUANTITY 1,200 1,000 200 100 Valley 545,000 2 400 9,000 105,000 6,000 3,000 unnel 56,000 100 2,500 600 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNiT UNIT AMOUNT COSTS CY 20 24.000 LF 25 25.000 SF 150 30.000 CY 35 3,500 17__.500 CY 7 3 815 .ooo LF 75 180__.000 SF 70 630,000 CY 15 1,575 .ooo LF 25 150,000 LF 35 105,000 45,000 CY 8 448,000 LF 80 8,000 CY 20 50,000 LF 25 15,000 (21 000) r~ I 14879-001 JOB NO NOV 1981 IDA TIE SHEET 13 OF 15 TOTALS AEMARI<S 100,000 36"~ and 48"!6 CMP 6,500,000 48"~ CMP 500,000 HAJ/APD PREPARED BY MF CHECKED BY -r J l- I j~--- CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL PROJECT TYPE OF ESTIMA1"E ALASKA POWER AUTHORITY ALTERNATIVE A PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT COSTS Access Road to Downstream p, ~er Tunnel Earthwork 215 000 CY 9 80 2.107.000 Culverts 800 LF 80 64.000 BridRe 3 000 SF 150 450.000 Subbase & Base 10 000 CY 21 210.000 Guardrail 9.000 LF 32 288.000 Snowshed & Slide Fall 1 000 LF ROO 800 000 Round-Off (19.000) Temt>orarv Construction Roada Earthwork 61 000 CY 6 366 000 Culverts 600 LF 80 48.000 Bridge 3.000 SF 150 450.000 Guardrail 2.000 LF 25 50,000 Round-Off (14.000) Road Maintenance Sunaner Season 45 MO 150.000 6,750,000 Winter Season 30 MO oOO,OOO 18,000,000 Round-Off 50,000 TOTAL ACCESS & CONSTRUCTION R( !ADS Hll!Cf CSE 523 (3-801 14879-001 JOB NO Nov 1981 DATE SHEET 14 OF 15 TOTALS REMARKS 48"~ CMP 3.900.000 48"~ CMP 900,000 24,800,000 59,600,000 ~I r-,-- \ ~T HAJ/APD 14897-001 PREPARED BV JOB NO NOV 1981 CHECKED BV DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 15 OF 15 TYPE OF ESTIMA TIE ALASKA POWER AUTHORITY ALTERNATIVE A PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNiT AMOUNT TOTALS REMARKS COSTS Transmission Line Clear & Grub 82 MI 225 000 18,450~000 Transmission Line 82 HI 343,000 28,126,000 Submarine Cable 21 MI 792,000 16,632,000 Round-Off (8,000) 63,200,000 TOTAL SPECIFIC CON:-> K :oN c OST AT .JANUARY lqR? PRH~F. T.F.VF.T.S 1,040,800,000 HGJCF CSIE 523 IJ.80) ALTERNATIVE B ESTIMATED COST ,~ I I ( ~~-f ---{ ~ tlJ HA:J/APD ES11MATE SUMMARY PREPARED BY MF CHECKED BY CONCEPTUAL CHAKACHAMNA HYDRQELECIRIC PROJECT TYPIE OF ESTIMATE ALTERNATIVE B i\10 DESCRIPTION PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT COSTS POWER PLANT STRUCTURE & IMPR< VEMENTS Valve Chamber Excavation & Supports 10,000 CY 275 Concrete & Reinf Steel 6.520 CY 410 Struc Steel & Mise Meta s 52 TON 1,800 Round-Off Un__l!erground Powerhouse Dewatering LS Excavation & Supports 58 900 CY 168 Drilling-Percus & Rotary 12 700 LF 27 Concrete & Reinf Steel 13.100 CY 630 Struc. Steel & Mise Metals 300 TON 5 300 Architectural LS Round-Off Bus Galleries Between Power house & Transformer Vaults Excavation & Supports 200 CY 825 Concrete 120 CY 290 Round Off HIICF CSE 623 (3-601 AMOUNT 2,750,000 2.673.200 93,600 (16_!_800) 4_,100 _,000 9,895,200 342,900 8,253,000 1,590_~000 1,000,000 18,900 165,000 34,800 200 TOTALS 5,500,000 25,200,000 200 .000 --l --' 14879-001 JOB NO NOV 1981 DATE SHEET 1 OF 15 REMARKS Ent1re Underground Complex 2"-3"0 ,--, I r-' -~ --, 1 ,' HAJ/ APD 14879-001 II'RIEPARED BY JOB NO MF NOV 1981 CHECkED BV DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 2 OF 15 TYi'E OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE B PREPARED FOR NO DESCRIIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS ~ Transformer ~all~rv & Tunne ~8 Excavation & Supports 11.960 CY 290 3.468.400 Concrete & Reinf Steel 830 CY 460 381.800 Struc Steel & Mise Metals 120 TON 3,800 456.000 Round. Off (6 .200) 4,300,000 Valve Chamber & Transformer Gallery~Access Tunnels Excavation & Supports 1,500 CY 250 375 000 \ Concrete 60 CY 290 17 400 Round-Off 7.600 400,000 Powerhouse Access Tunnel Portal Excav & Protection 36 ,ooo CY 1:0 560.000 Portal Cone & Reinf Steel 1,000 CY 370 570,000 Tunnel Excav & Supports ~4,-000 CY 300 7.200,000 Tunnel Concrete 900 CY 290 261,000 Tunnel Mise Metals 30 TON 11,000 330,000 Subsurface Exoloration Mobilization LS 1,500,000 Exploratory Arlit 1,000 LF 1.800 1,800,000 Core drilling 5,000 LF 140 700,000 I Helicopter Service LS 600,000 Round-Off (21.000) 13,500,000 H&Cf CSE 623 (3-801 HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION Cable Wav C:nnc.r~t~ & R~inf St~~l Mim:. Metals & Cable Suo Pnrt Psm~lA Round-Off TOTAl. POWER PLANT STRUCTURE HBlCF CSE 523 13-801 f l ~ 1 CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 1,000 CY 700 700,000 26 TON 5' 100 132,600 (32,600) U'U'K' IVJ!.l'll'..l'll·. >:J ' ) TOTALS !:SUU,UUU 49.900,000 14879-001 JOB NO NOV 1981 DATE SHEET 3 OF 15 REMARKS ,- I~] ,.._-- \ ___ l HAJ/APD 14879 om PREPARED illY JOB NO MF NOV ll.981 CHECICED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET .., 4 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE B PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT COSTS AMOUNT TOTALS REMARKS RJi'c:!' nAM Fr. WATF.R'IJAYS Doo<>!l"un.,r u,t-Pr T.auP1 R~rnrclino LS 100.000 Tno-q\rp ~,. ... ,.,.o-ur~ c:!.ftp F.xn11oratinn Mnh-! l i '7<1 t--f nn ILS 150.000 ('_n,... ih-.W11 i ,.,.,. 5 000 ILF 80 400.000 u., 1 .f ,.,.~~~-..... c::: ........ """ IT.S 150 000 "''"""""1 ii'v""'" ~ ~nnnort"R 10.000 CY 510 5,100,000 T, ... -... 1 l'nnl' F. Ro-lnf: St"PP 90 cr 350 31.500 lq\rp-T.an (1i'in.<~1 RnBUnti) ILS 2,500,000 L 26' 'Dl "'""" I.."' n. Tomn ._Cnnr 550 lr.v 700 3R5 000 -~ n~uino r. .... ,..., 60 I nAYS 10 000 600.000 1DI'1!nnn<il:t11if f' (16,500) 9.300.000 Tnt--'llr~'> r.at-P Sh.,ft Sh<1ft" F.Yf"<>U F. ~ilnnn .. t-R 10 000 CY 36C 3,600.000 M:~q!'l Stn•f.,,.,. F.xr:~ 50 000 ICY 30 1.500 .ooo Conc.rPtP F. RPi_nf St-PPl 5,200 lev 890 4.628 000 M:lAr MPf-<>1 a f!.:at-.. ., I. Hni It-220 I TON 12 ._200 2,684.000 lllnun.-1-0ff (12,000) 12 400 000 H&CF CSIE 523 (3.001 l __ ) ~~~ ~--~ L -) PREPARED BY MF CHECKIED BY CONCEPTUAL YYPIE OF ESTDMATIE ALTERNATIVE B NO DESCRIPT~OIIil Access Tunnel at Intake Portal Excav & Protectio Ttmnel Excav & Suooorts Tunnel Cone & Reinf Stee Round-Off Access Tunnel at Suree Cham Portal Excav. & Protectio Tunnel Excav & Suooorts Tunnel Cone & Reinf Stee GroutinR Contact & Pressu: Wateright Bulkhead & Fram Round-Off Power Tunnel Excavation & Suooorts Concrete Groutin2 Contact & Pressu~ Round-Off \ HQCF CSE 523 13-801 r l CRAKACHAMNA HYDROELECTRIC PROJECT er ·e ~e PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT cosvs 6.000 CY 50 300 000 60.000 CY 312 18.720.000 170 CY 500 85 000 (5 .000) 6.000 CY 35 210.000 14 000 CY 317 4 438 000 1. 700 CY 420 714.000 2.260 CF 58 131 080 27 TON 13.800 372.600 34 320 53.400 LF 8.372 447.064.800 348,000 CY 334 116.232.000 317 .ooo CF 54 17.118.000 (14.800) -~ 14879-001 JOB NO NOV, 1981 DATE SHEET 5 OF 15 TOTALS REMARKS 19,100,000 5,900,000 580,400,000 1 -- 1 -J HAJ/APD PREPARED BV MF CHECKED BY CONCEPTUAJL TYPE OIF !ESTIMATE ALTERNATIVE B NO DESCRIPTION Su.rlle Chs:~mh211" -Uoner ll<' ............ "'tinn 1. co .. ----1:-o. Concret:e & Reinf St-PP1 Eal!"t"hwnrkA 1. FPn ... in~ Round-Off P«"'!nAtnck=lnl"1-fnPd s ..... f'inn li'YI"nn"''tinn 1. Snnnn..-t-a Concrete & Reinf Steel Grout:in~ Contact & Pres Round-Off Penstock-Ho~izontal Sectio F.xcavation & Sunnorts Concr2te S R2inf St2e1 Groutin2 -Contact Round-Off HBICF CSE 623 (3-801 J -j ~--~} ( --_] CJ CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 25 .500 r:v 227 5,788,500 5 500 r.v 880 4,840,000 15.000 r.v 27 405,000 (33,500) 24_ 000 CY 306 7,344,000 10 500 CY 845 8,872,500 sure 5 .500 CF 52 286,000 (2.500) n & Elbow 12.000 CY 334 4,008,000 5.100 CY 365 1,861,500 2 600 CF 50 130,000 500 ~-l I I~~, 1~l __ _) - TOTALS HeJ.1port u.ooo 000 16,500,000 6,000,000 r 14879-001 JOB NO NOV. 1981 DATE SHEET 6 OF 15 REMARKS Storal!e Work Area - \ ~ ) HAJ/APD PREPARED BY MF CHECKED BY ~---\ CONCEPTUAl, TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION PIPnafl"n,..lr-Wv@ Br.<~nl"hiPa to V.E Excavation & Supports Concrete & Reinf Steel Steel Liner Grouting-Contact Round-Off Penstock Between Valve Chan Excavation & Supports Concrete & Backfill Round-Off Draft Tube Tunnels Rock Bolts & Grout Concrete & Reinf Steel Round-Off - Surge Chamber -Tailrace Excavation & Supports H&CF CSE 523 (UO) -[J I r _-__-_ J 14879-001 JOB NO NOV 1982 DATE CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 7 OF 15 ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS 11 ve Chamber 9.000 CY 480 4.320 000 6.100 CY 608 3.708.800 700 TON 5 000 3.500 000 7.000 CY 56 392,000 (20,800) 11,900,000 ber & Powerhom e 850 CY 440 374.000 500 CY 550 275.000 (49.000) 600,000 15.000 LF 29 435,000 2.975 CY 425 1,264,375 625 1,700,000 5.000 CY 480 2,400,000 - l--1 l _j (_-~I r-1 I I I c~-j I I I __ j HAJ/APD 14879-001 IP'REPARED BY JOB NO MF-NOV 1981 CHECKED BY DATE CONCEPTUAl. CHAKACHAMNA HYDBOEI.ECTRTC PRO.JECT PROJECT SHEET 8 OF 15 TYPE OF ESTIMATE ALTERNATIVE B ALASKA POWER AUTHORITY PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Tailrace Tunnel & Structu~Es Cnff~rdam & Dewaterinll LS 2 .ooo.ooo Portal Excav & Protecti(n 2,000 CY 65 130,000 C'.nncrete & Reinf Steel 1 200 CY 600 720,000 'IJ$1lkwav Bridlle LS 65,000 Stoolo2s & Hoists 81 TON 8,500 688,500 Tunnel Excav & Suonorts 20,000 CY 290 5,800,000 .PlUIZ li'.v,.<~uqtion 4,000 CY 50 200,000 Round-Off (3 ,500) 9,600,000 T$1-flT$11">'> r.Jt.qnnPl r.hann~l Excavation 80,000 CY 9 720,000 (20,000) 700...!.000 River Traininll Works River Bed Deepening 50,000 CY 10 500,000 Mech & Elec LS 6,100,000 \ TOTAL RESERVOIR, DAM AND W~ TERWAYS 694,200,000 H&CF CSE 623 13-801 ~~ ---, ,----- l_ J ( L - HAl/APD tiiJ PREPARED BY MF CHECKED I!IV CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION Turbines & Generators Turbines Generators Round-Off Accessorv Electrical Eouio11 tent Eauioment Mise Power Plant Equioment Crane Brid2e Other Power Plant Eouio Switchvard Structures Earthworks Concrete & Reinf Steel Struc Steel & Misc.Meta s Round-Off Hli!CF CSE 623 (3-801 _j I j I_ -~ - J CHAKACUAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 4 EA 8~11ITI 33,920,000 4 EA 16,00(\0lJi 24,.000,000 12U;lYOUJ LS 1 EA 930,000 LS 6,370.000 15.000 CY 25 3/5,000 3.800 CY 640 2.432.000 225 TON 3,500 787.500 5 500 TOTALS 330 MW 'J 1, ~uu ,uuu ~,'JUU,UUU 7,300,000 3 ,6oo t_ooo I _, ( ------. \ --j 14879-001 JOB NO NOV 1981 DATE SHEET 9 OF 15 REMARKS r - HAJ/APD PREPARED BY CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION Switchvard Eauioment TrAnAfnnn~rR 105 MVA Unit. & Line Breakers ~uf tl"'h~A & Lil1htn..Aue_at~ rs . 230 KV . cables Controls & Metr'2 [Quip Rmmd Off Commun1cat1on and Sun:v Cont.rol Eauio HlaCF CSE 623 13-801 - CHAKACHAMNA HYDROELECTRIC PROJECT QUANTITY 5 7 30 18~000 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNIT UNIT AMOUNT COSTS EA I!,OJOPO< 5,150,000 EA 185,00 ~ 1,295,000 EA 34,00~ 1,020,000 LE_ 130 2,340,000 LS 2,700,000 _{5__,0001_ LS ( ~- TOTALS 12,500,000 1,600,000 r-- 1 I_~ r-l I l -- 14879-001 JOB NO NOV. 1981 DATE SHEET 10 OF 15 REMARKS - L_ -\ L HAJ/APD PREPARED BY ME CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION TRANSPORTATION FACILITIES Port Facilities Causeway Trestle Piles Trestle Struct Steel Trestle Reinf Cone Facilities -Allowance Round-Off .... Airport Earthwork Culverts Subbase & Base Building -Allowance Round-Off H&CF CSE 623 (J.80) I _) -I I -I I_-J -__ _] ESTWATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 19,600 CY 80 1.56R.OOO 50 TON 11 300 565 000 110 TON 3 500 385 000 150 CY 700 lO'i.OOO LS 2.000 000 _(23 000) I I 54.'100 CY 16 872,000 1.000 LF 65 65,000 55 ()()() CY 14 170,000 LS 300,000 (7_,000) _I 14879-001 JOB NO NOV 1981 DATE SHEET 11 OF 15 TOTALS REMARKS ) L = 150 LF ID12 II t = !..," 4.600.00 ~ 2.000,000 ,-J -J HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 12 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE B PREPARED FOR UN IV ~ NO DESCRiPTION QUANTITY UNIT COSTS AMOUNT TOTALS REMARKS A ........ aa & Construction~ . Mil~~ ..1Hfi(l -t.n .lil±OO_ F.AT "'-.1. 175.000 CY 6.60 1 .155.000 r.ul"'le.rt.s. 1.500 LF 65 97 .500 36 11 0 CMP B r id.lle.s. 1.400 SF 150 210 000 Subbase & Base 85.400 CY 15 1 281 000 f.lanA l!"cl RA i 1 1 200 LF 25 ..10_ ..illlli. R~nair Erlstinll _Road 95.000 LF 10 950~000 ~nnw F~P>nrPA 5o000 LF 35 17.5_ 000 Round-Off 1 .500 3.900.000 Milt<> ]fU-00 t-n 15+00 Ji'..a~ 1,465,000 CY 6 60 _2_ 66_2_ 000 Culverts 3,600 LF 80 288_.,000 48n!6 CMP Subbase & Base 165.000 CY 15 2 475 000 Guard Rail 13,000 LF 25 325 000 B.enai.r .Exis tlrut _Borul 16,000 LF 10 160 000 Snow Fencea 1,000 LF 35 35_,000 Round~Off 48,000 13 000.000 Mile .35±0n _to ..39±00. F.arthwork 445,000 CY 8 30 3 693 500 Culverts 1,000 LF 80 80,000 . 48"c.6 CMP _B r idlz.e._ 9.000 SF 150 1 350 000 .Suhha.sa ..&.. Bage 38,000 CY 15 570 000 Guard Rail 10,000 LF 27 2701.000 Snow ~enc.ea 2,000 LF 35 70 000 'Rnimrl-Off (33 500) 6 .ooo non HI!CF CSE 623 13-801 -1 I HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE B NO DESCRIPTION Walkwav To Gate Shaft Earthwork Guard Rail BridRe Ri_prap Round-Off Access Road to MacArthur Earthwork Culverts Brid~e Improvements Subbase & Base Guard Rail Snow Fences Round-Off ,&,.,..>aa Road to Tailrace _Earthwork Culverts Subbase & Base _Guard Rail Round-Off - HIIICF CSE 523 (~0) ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT QUANTITY 1.200 1 000 200 100 Valley 545 000 2.400 9.000 105.000 6.000 3 000 unnel 56 000 100 2.500 600 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNIT UNIT AMOUNT COSTS CY 20 24.000 LF 25 25 000 SF 150 30.000 CY 35 3,500 17.500 CY 7 3,815 .ooo LF 75 180.000 SF 70 630,000 CY 15 1,575,000 LF 25 150,000 LF 35 105.000 45,000 CY 8 448.000 LF 80 8,000 CY 20 50,000 LF 25 15,000 (21,000) j -- L ,- 14879-001 JOB NO NOV 1981 DATE SHEET 13 OF 15 TOTALS REMARKS 100,000 36"~ and 48"~ CMP 6,500,000 48"gS CMP 500,000 I~-=-~ HAJ /APD 14879-001 PREPARED BY JOB NO MF Nov 1981 CHIECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 14 OF 15 TYPE OF IESTIMATIE ALASKA POWER AUTHORITY ALTERNATIVE B PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS Access Roaa to l>ownstream lf( ilier Tunnel Earthwork 215,000 CY 9 80 2,107,000 Culverts BOO LF 80 64,000 48".P CMP Brid2e 3,000 SF 150 450,000 Subbase & Base 10,000 CY 21 210,000 Guardrail 9,000 LF 32 288,000 Snowshed & Slide Fall 1,000 LF 800 ---srrrr,uuu Round-Off -cr9;omry J,~uu.uuu Temporarv Construction Roads Earthwork 61,000 CY 6 366,000 Culverts 600 LF 80 48.000 48"~ CMP Bridge 3,000 SF 150 450,000 Guardrail 2,000 LF 25 50,000 Round-Off (14.000) 900,000 Road Maintenance Summer Season 45 MO 1150,000 6,750,000 Winter Season 30 MO ~00,000 18,000,000 Round-Off 50.000 24,800,000 ITOTAI AIY~P.~~ F. flNS' 'll ION RO lns 59,600,000 HilzCF CSE 523 13-80) I _-__ I -I HAJ/APD 14897-001 PREPARED BV JOB NO MF NOV 1981 CHECKED BV DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 15 OF 15 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE B PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Transmission Line Clear & Grub 82 MI 225,000 18,450,000 TrAnami t:u:d nn Line 82 MI 343,000 28,126,000 Submarine Cable 21 MI 792,00( 16,632,000 Round-Off (8t0QQ) o:J ;zmr ;uou TOTAL SPECIFIC CONSTRUCTION COST AT JANUARY 1982 PRICE LEVELS 965,900,000 H&CF CSE 523 13-801 ALTERNATIVE C ESTIMATED COST ~I HAJ/APD ESnMAYE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 1 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS POWER PLANT STRUCTURE & IMPR( VEMENTS Valve Chamber Excavation & Supports 10,500 CY 270 2,835,000 Concrete & Reinf Steel 6,520 CY 410 2,673,200 Struc Steel & Mise Meta s 52 TON 1,800 93,600 Round-Off ll~800) ~,bUU,UUU Un__()_erground Powerhouse Dewaterin~ LS 4,100,000 Ent1re Underground Como1ex Excavation & Supports 04,000 CY 155 9 920 000 Drilling-Percus & Rotary 15,UUU LF 30 450.000 2 11 -3"0 Concrete & Reinf Steel 14,200 CY 630 8,946,000 Struc Steel & Mise Metals 330 TON 5_}_300 1. 749 000 Architectural LS 1,000,000 Round-Off 35,000 26,200,000 Bus Galleries Between Power house & Transformer Vaults Excavation & Supports 200 CY 825 165,000 Concrete llU CY :z~u 34,800 Round Off 200 200 000 HIIICF CSE 623 13-801 r--\ ~ .. ~ ~~~) - HAJ/ APD PREPARED BY II i:S11MATE SUMMARY 14879-001 JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 2 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE c PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS Transformer Gallerv & Tunne s Excavation & Suooorts 11 960 CY 290 3.468.400 Concrete & Reinf Steel 830 CY 460 381,800 Struc Steel & Mise Metals 120 TON 3,800 456.000 Round Off (6 .200) 4,30U,UUU Valve Chamber & Transformer Gallery-Access Tunnels Excavation & Supports 1.500 CY 250 375,000 Concrete 60 CY 290 17,400 Round-Off 7.600 400,000 Powerhouse Access Tunnel Portal Excav & Protection 56,000 CY rrr %0 000 Portal Cone & Reinf Steel 1,000 CY 510 570 000 Tunnel Excav & Supports 24,000 CY -mer 7 'lOO 000 Tunnel Concrete 900 CY 290 261 000 Tunnel Mise Metals 30 TON 11,000 330 01)0 Subsurface Exoloration Mobilization LS 1 500 000 Exploratory Adit 1,000 LF 1.800 1 800 000 Core drillinR 5,000 LF 140 700 000 Helicopter Service LS 600 000 Round-Off <21 ooo) 13 500 000 H&CF CSE 623 13-801 -----=::..,- HAJ[APD IIJ ESYVMATE SUMMARY PREPARED BY 14879-001 JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 3 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE c PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT COSTS AMOUNT TOTALS REMARKS Cabl"" Wav r.nnc.re.t"" F. R .. inf St .... l 1 000 r.v 700 700,000 Miat!.Me.tals F. C.<~h1e. Sun. 26 TON 5.100 132,600 'PnTt P.<~nPlA Rnunrl-Off (32,600) 800,000 TOTAl. POWF.R PT.ANT STRlir·-· tllF. TMPRI IVI(MI<;N' IS 51,000,000 HBICF CSE 623 13-80) -- HAJ'/APD ESTIMATE SUMMARY 14879 001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT DATE PROJECT SHEET 4 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT COSTS AMOUNT TOTALS REMARKS R~<~!;lJt:RVOTR OAM F. t.JA"'"'n .... rs DAga.-un-f..- lJA t-a..-T """' ... 1 RPrn,..t i no LS 100 000 Tnt-AkP t;;lt--rtrt"n-rP Sff"p Rvnlnr;:~t-fnn Mnh-11~ "">t-i nn J.S 150,000 r"" ..... n...f ll.fno 5.000 IJ.F 80 400,000 Uol-f~~ ... t-a..-C::o-ruiro<> IT.s 150.000 Tunn<> 1 ..,,_. .... F. Snnnnr t-.. 12,000 !CY 470 5,640,000 Tnnnol f'~n~ F. Do-f~f St-<><> 100 rY 350 35,000 T-<>lr~~>-T,.n (Fin<>l llnnnn\ ILS 3,000,000 L 26' Pl.,._.., L n" TAmn r.nnr 600 lrv 700 420.000 nfuino r ........ -. 60 I nAYS 10.000 600,000 Rntan..t:nff 5,000 10,400,000 Int-ak~ Gat~~> Sh;:~ft- Shaft F.Yr<>u F. C::nnnro-rt-a 10.000 CY 360 3.600.000 M;:~AI'I Surf;:~I"P Rvroqu 50,000 lrY 30 1,500,000 C:r~~-"'t-P F. RPfnf StPII>l 5,700 lrv 890 5.073.000 MiRr MPt-~l .. "r.<>t-<>a F. Hni ~t 244 l'l'ON 12,500 3,050,000 Rnnn..'I-OFF (23 000) 13 200.000 HBICF CSE 623 (3-80) HAJ/APD PREPARED BY MF CHECt(ED BY CONCEPTUAL VY!i'E OF ESTIMATE ALTERNATIVE C NO DESCRIPTION Access Tunnel at Intake Portal Exeav 61 Proteetio Tunnel Exeav & Suooorts Tunnel Cone & Reinf Stee Round-Off Access Tunnel at Sur2e Cham Portal Exeav. & Protectio Tunnel Excav.& Suooorts Tunnel Cone & Reinf Stee GroutinR CnntAt".t & PressUJ Rc;mnd.-Off Hli!CF CSE 623 13-801 ---j ~, CHAKACHAMNA HYDROELECTRIC PROJECT er :e PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT COSTS f.o.OOO CY 50 72 000 CY 295 200 CY 500 6 000 CY 55 23 000 CY 323 2.300 CY 420 3.400 CF 58 AMOUNT 300.000 21.240 .ooo 100.000 (40.000) 330.000 7.429.000 966,000 197.200 (22.200) 14879-001 JOB NO NOV 1981 DATE SHEET 5 OF 16 TOTALS REMARKS 21,600,000 8,900,000 • r--~ -<--(<::..__-~ -------j-.) --\ r I ' ! ) \) ' ' \ ' )_ --" '-----/ "--= v-' ~~- I -) '-~ ~ _./" ~ ESTIMATE SUMMARY HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 6 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS Access Tunnel at M1le 3 5 No 1 Portal Excav & Protect1on 6,000 CY 53 318,000 Tunnel Excav & Supports 68_,000 CY 297 20,196,000 Tunnel Cone & Reinf Steel 500 CY 430 215,000 Grout1ng-Contact & Pressure 1,125 CF 58 65,250 Round-Off 5.750 20,800,000 Access Tunnel at Mile 7 5 No 2 Portal Excav & Protect1on 6,000 CY 54 324,000 Tunnel Excav & Supports 45,000 CY 298 13,410,000 Tunnel Cone & Re1nf Steel 1 600 CY 420 672,000 Grout1ne:-Contact & Pressure 2 300 CF 58 133,400 Round-Off (39,400) 14,500,000 Power Tunnel Excavat1on & Supports 67 000 LF 7.698 515,766,000 Concrete 514,000 CY 334 171,676,000 Grout1ng-Contact & Pressure 464~000 CF 54 25,056,000 Round-Off 2,000 712,500,000 H&CF CSE 523 (3-80) r--- ( -=-11 ,-"-\ '-~~!; HAJ/APD MJ ES11MA11E SUMMMV PREPARED BY 14879-001 JOB NO MF CHECKED BY NQV. ]981 DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 7 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE c PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT COSTS AMOUNT TOTALS REMARKS Sur1111> r.hamb~r -Uoner .... ~,.~· Ltion & !=:unnnrt:A 35 500 ("{ 200 7 100,000 Con~rPt"P & R~inf .St:~l"l 6.100 ("{ 880 5,368,000 RArt"huorkR & Ji',.n,.inP 15.000 f'.V 27 405,000 Heliport, Storage, Work Area Rnnnrl-{)ff 27.000 12~900,000 I P~nR~n,.lr-Tnl'l in<u'l SPI'f"inn !:'~~~· tinn & SnnnnrtR 23.400 CY 271 6,341,400 Concrete & Reinf Steel 10,500 CY 837 8,788,500 Groutin2 Contact & Pres !sure 5,000 CF 52 260,000 Round-Off 10,100 15-;-ziUO,OUO Penstock-Horizontal Sectio n & Elbow Excavation & Suooorts 14.000 CY 310 4 340,000 f'.onr.rete S R~i nf Steel 6.000 CY 365 2.190,000 Grontim~ -Contact 3.000 CF 50 150,000 Round-Off 20.000 6 700.000 -illaCF CSE 623 13-601 J~ ~ tESIJ1!M~11E SflllMM~Y 14879-001 JOB NO ll'REPARED BY HAJ/APD NOV 1982 CHECKED BY DATE CONCEPTBIAX. CHAKACHAMNA HYDROELECTRIC PROJECT 8 16 PROJECT SHEET OF TVPE OF ESTIMATE ALASKA fOWER AUTHORITY PREPARED FOR ALTERNATIVE C NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS 'PDnat-n.,..1r~WvP-Rrs:~n.,..hoa ll"n VSI lve Ch.amber Excavation & Supports 10,000 CY 432 4,320,000 Concrete & Reinf Steel 7,200 CY 608 4,377,600 Steel Liner 650 TON s.ooo 3,250,000 Grouting-Contact 3,000 CY 50 15_9,000 Round-Off 2,400 12 ,100 .ooo Penstock Between Valve ChaE her & PowerhoU! e Excavation & Supports 1 000 CY 440 440.000 Concrete & Backfill 600 CY 550 330.000 Round-Off 30.000 800,000 Draft Tube Tunnels Rock Bolts & Grout 19 000 LF 27 513 .ooo Concrete & Reinf Steel 3~300 CY 425 1.402,500 Rotmd-Off (15.500) 1,900,000 Surge Chamber -Tailrace Excavation & Suooorts 5 000 CY 480 2.400,000 HGICF CSE 523 13-801 • ,~-~ /-'-.~ 1-=:: J ~-~, .<:;_-~-] {£_____> ~~ .. \ _ __,) \ ( --=-J\ l"'---,f-~~ ( ~ ::_ --J \ ! r l '---~ ,., \~ __J ~---~ -~ ~~- " - HAJ/APD 14879-001 PREPARED BV JOB NO MF NOV 1981 CHECKED BY DATE CONCEPTUAl. CHAKACHAMNA HYDROEJ.ECTRTC PRO.JECT PROJECT SHEET 9 OF 16 TYPE OF ESTIMATE ALTERNATIVE C ALASKA POWER AUTHORITY PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS cosrs Tailrace Tunnel & StructurEs Coffelt"dam & Dewaterinll LS 2.000,000 Portal Excav. & Protecticn 2,000 CY 65 130 000 C4 !te & Reinf Steel 1.200 CY 600 720 000 IJ .. l1ru .. v Brid2e LS 65,000 Stoololls & Hoists 81 TON 8,500 688,500 Tunnel Excav & Suonorts 25,000 _CY_ 260 6,500,000 Plu11 li'v"""'•"\tion 4,000 CY so 200,000 Round-Off (3 ,500) 10,300,000 TAilrAl'd'> r.h~nnPl C. I-•1 li'~~~ ''ltion 100,000 CY 9 900,000 River Traininll Works River Bed Deepening 50~000 CY 10 soo.ooo Mech & Elec LS 5,700,000 TOTAL RESLRVOIR, DAM AND wt TERWAYS 871,600,000 H&CF CSE 623 (3<80) ;' --I ~=----~) "----.............---.---..... ~....._ HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1981 CHECKED BY DATIE CONCEPTUAL CHAKACHAMNA HYDROELECTBIC PROJECT PROJECT SHEET 10 OF 16 TYI'IE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRiPTiON QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Tul!."bines & Generators 300 MW Turbines 4 EA 7.970,00 31,880,00( Generators 4 EA 5,660,00 22,640 ,00( Round-Off 120 .ooc I) 54,500,000 Accessorv Electrical Eauior ent Eauioment LS 9,000,000 Mise Power Plant Eauivmen Crane Brid2e 1 EA 900 ,00< Other Power Plant Ecruip LS 6,000.00( b,YUU,UUU - Switchvard Structures Earthworks 15.000 CY 25 375 ,OOl Concrete & Reinf Steel 3,800 CY 640 2,432 ,oar Stl!."UC Steel & Mise Meta s 225 TON 3,500 787,50( Round-Off 5 ,50( 3,600,001 HIICF CSE 623 f:WWI I I \ /~ - PAJ/APD 14879-001 PREPARED BY JOB NO MF NOV. 1981 CHECKED BY Cl~CHAMNA HYDROELECTRIC PROJECT DATE CONCEPTUAL PROJECT SHEET 11 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTiTY UNIT UNIT COSTS AMOUNT TOTALS REMARKS Swit:chvard Eauioment 1'r.Qnqfl 10'\ MVA 5 EA 1,010,00 5,050,000 Unit-& Line Breakers 7 EA 180,00 1,26(),00() ~wi t-rnQa & T,i t>ht:n Arrestc rs 30 EA 33,00( 990,000 210 KV Cables 18,000 LF 12C 2,160,000 Cont:rols & Metr'2 r:auio LS 2,630,000 Rnamrl Off 10,000 12,100,000 "'"'"""' Rupv C.onrrol Eau1 n LS 1,600,000 -H&CF CSE 523 13-601 HAJ/APD PREPARED BY ( ~ . , __ l r ESTIMATE SUMMARY l~ -=---"" I --<' 1 .. 14879-001 JOB NO NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 12 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS TRANSPORTATION FACILITIES Port Facilities Causeway 19 600 CY 80 1 568 000 Trestle Piles 50 TON 11 300 565 000 L = 150 LF. ~12". t = ~" Trestle Struct Steel 110 TON 3,500 385,000 TrestTe Reinf. Cone 150 CY 700 105.000 Facilities -Allowance LS 2,000,000 Round-Off (23 ,000) 4.600.000 Airport I Earthwork 54.500 CY 16 872,000 Culverts 1 000 LF 65 65,000 Subbase & Base 55 000 CY 14 770,000 Building -Allowance LS 300,000 Round-Off (7 ,000) 2.000,000 H&CF CSE 623 13-801 r~l \-:__] HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE C NO DESCRIPTION At',.PAA & Construction Roads MilP 0+00 l"n 1R+00 F.archwork C.nlVPTI"R Brida~A SuhhAA~~> & Base l':nATrl RAi 1 ~nair Existinll Road ~nnw FPnl'PA Rmmrl.-Off Mi 1 ~~> 1 R+OO t-n 11H-00 F.Art"hunrlra Culverts Subbase & Base Guard Rail R~nair F.xistim~ Road Snow Fences Round-Off Mil~ 35+00 to 'lQ+OO Earthwork Culverts BriduP Suhhase & Base Guard Rail Snow Fences Rnund-Off HBICF CSE 623 (J.8DI r --">-~ I I ~ l I ~ ' ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTIIORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 175,000 CY 6 60 1,155,000 1,500 LF 65 97,500 1,400 SF 150 210,000 85,400 CY 15 1,281,000 1.200 LF 25 30,000 95,000 LF 10 950,000 5,000 LF 35 175,000 1,500 1,465,000 CY 6 60 9,669,000 3,600 LF 80 288,000 165,000 CY 15 2,475,000 13,000 _LF 25 325,000 16,000 LF 10 160,000 1,000 LF 35 35,000 48,000 445,000 CY_ 8 30 3,693,500 1,000 LF 80 80,000 9,000 _SF 150 1,350,000 38,000 CY 15 570,000 10,000 LF 27 270,000 2,000 LF ~ 35 70,000 (33,500) ~ r I TOTALS 3,900,000 13,000,000 6.000,000 .. 14879-001 JOB NO NOV 1981 DATE SHEET 13 OF 16 REMARKS 48"!6 CMP 48"!6 CMP :~-=:.l HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATe ALTERNATIVE C NO DESCRIPTION Walkwav To Gate Shaft Earthwork Guard Rail BridRe Riorao Round-Off Access Road to Tailrace T1 Earthwork Culverts Subbase & Base G~ard Ra1l Round-Off H&CF CSE 523 (3-801 / I I ES11MATE SUMMARY CUAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 1~200 CY 20 24,000 1,000 LF 25 25,000 200 SF 150 30,000 100 CY 35 3,500 17.500 nnel 56,000 CY 8 -li4!f ,lmlJ 100 LF 80 8,000 2,500 CY 20 50,000 600 LF 25 15,000 (21,000) (~ - I .. 14879-001 JOB NO NOV 1981 DATE SHEET 14 OF 16 TOTALS REMARKS lUU,IJUU 4H"!6 CMP .:>UU,UUU HAJ/APD ESTIMATE SUMMARY 14879-001 PREPARED BY JOB NO MF Nov 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 15 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE C PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Access Road to Downstream p, ~Wer Tunnel Earthwork 215 000 CY 9 80 2.107.000 Culverts BOO LF 80 64.000 48'¢ CMP BridRe 3.000 SF 150 450.000 Subbase & Base 10,000 CY 21 210,000 Guardrail 9,000 LF 32 288,000 Snowshed & Slide Fall 1.000 LF 800 800.000 Round-Off (19.000) 3,900,000 Temporarv Construction Road~ Earthwork 61.000 CY 6 366.000 \ Culverts 600 LF 80 48,000 BridRe 3,000 SF 150 450,000 Guardrail 2,000 LF 25 50,000 Round-Off (14.000) 900,000 Road Maintenance Summer Season 36 MO 120,000 4,320,000 Winter Season 24 MO 480,000 11,520,000 Round-Off (40,000) 15,800,000 TO'J'AT. Ar.r.F.~~ Fv IINS' 'H lr.'l'TON 1 loAns 44 100.000 \ - HIICF CSE 523 13-801 -~ J HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE C NO DESCRIPTION Transmission Line Clear & Grub TrAAsmiasion Line Submarine Cable Round-Off TOTAL SPECIFIC CONSTRUCTION C AT JANUARY 1982 PRICE LEVELS ~ HSICF CSE 623 (3-801 OST ( ' l J '-- ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 70 MI 725.,000 15,750,000 70 MI 344 000 24.080.000 21 MI 792,000 16,632,000 38.,000 I......_-J 14897-001 JOB NO NOV 1981 DATE SHEET 16 OF 16 TOTALS REMARKS 56.500.000 1,117,_500,000 I ALTERNATIVE D ESTIMATED COST ,--1 r - \ __ __ .. HAJ/APD ESTIMATE SUMMARY PAIEPAAED BY MF CHECKED BY PROJECT CONCEPTUAL CUAKACHAMNA UYDBOELECIRIC PROJECT TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT COSTS POWER. PLANT STRUCTURE & IMPR( VEMENTS Valve Chember Excavation & Supports 10,500 CY 270 2,835,000 Concrete & Reinf Steel 6,520 CY 410 2,673,200 Struc Steel & Mise Meta s 52 TON 1,800 93,600 Round-Off U 2 H001 Underground Powerhouse Dewatering LS 4,100,000 Excavation & Supports 64,000 CY 155 _9.920 000 Drilling-Percus.& Rotary 15,000 LF 30 MO .ooo Concrete & Reinf Steel 14,200 CY 630 8,946,000 Struc. Steel & Mise Metals 330 TON 5,300 1.749,000 Architectural LS 1,000,000 RoiWld-Off 35,000 Bus Galleries Between Power house & Transformer Vaults Excavation & Supports 200 CY 825 165,000 Concrete llO CY :.!90 34,800 Round Off 200 ~· HlrCF CSE 623 134101 TOTALS .:J 1 bUU 1 UUU 26,200,000 200 000 -----~ I r--~ I I JOB NO NOV 1981 DATE SHIEEV OF 16 REMARKS Entire Underground Como lex _2"-31iti ~~ I l HAJ/APD PREP'ARED BY MF CHECCCEO IV CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE D 1110 DESCRIPTION POWER PLANT STRUCTURE & IMPR( Valve Chamber Excavation & Supports Concrete & Reinf Steel ( L-I CHAKACUAMNA HYDRQELECIRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNiT UNIT AMOUNT COSTS VEMENTS 10,500 CY 270 2,835,000 6,520 CY 410 2,673,200 Struc Steel & Mise Meta s 52 TON 1,800 93,b00 Round-Off (1, tsUU) Un!Jer_g_round Powernouse Dewatering LS 4,100,000 Excavation & Supports 64,000 ex 155 9 .920 000 Drilling-Percus.& Rotarv 15,000 LF 30 450.000 Concrete & Reinf Steel 14,200 CY 630 8,946,000 Struc Steel & Mise Metals JJO TON 5,300 1,749,000 Architectural LS 1,000,000 Round-Off 35,000 Bus Galleries Between Power house & Transformer Vaults Excavation & Supports 200 CY 825 165,000 Concrete lZU CY z~u 34,800 Round Off 200 I......- H&CF CSE 623 IUOI r ~I I c-) JOB NO NOV 1981 DATE SHEET ] OIF 16 TOTALS REMARKS :J,bOU,OOU Entire Under2round Como lex 2 11 -3"0 26,200,000 200.000 l __ J (~ ' ,---, .--~ -~----~ [~~1 r I I L --I I I ~ 1 ""'~-~-' c-1 ~~- r--1 /- 14879-001 f>REPARED IIV JOB NO MF NOV 1981 CHECKED IIY DATE SHE IE"!' 2 OF 16 CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DIESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS RIEMARKS COSTS TY"AnAf:ormer Gallerv & Tnnne lls Excavation & Supports 11 960 CY 290 3,468,400 Concrete & Reinf Steel 830 CY 460 381,800 Struc Steel & Mise Metals 120 TON 3,800 456,000 Round Off (6,200) 4,300,UOO Valve Chamber & Transformer Gallery-Access Tunnels Excavation & Supports 1.500 CY 250 375~000 Concrete 60 CY 290 17,400 Round~Off 7,600 400,000 Powerhouse Access Tunnel Porte! Excav.& Protection 56,000 CY 10 560 000 Portal Cone & Reinf Steel 1,000 CY 570 570.000 Tunnel Excav & Supports 24,000 CY 300 7 .200 000 Tunnel Concrete 900 CY 290 261 000 Tunnel Mise Metals 30 TON 11.000 330_~000 Subsurface Exploration Mobilization LS 1 500~000 Ex~loratory Adit 1,000 LF 1~800 1 800_._000 Core drilling 5,000 LF 140 700 000 Helicoi!_ter Service LS 600_._000 Round-Off (21 000) 13 500 000 H&CF CSE 623 13-801 -, L __ HAJ/APD PREPARED 81f MF CHECKED illY CONCEPTUAL TYPE OF IESTU\IIAl'IE ALTERNATIVE D NO DESCRIPTION Cable Wav ,._ !f"~ & R~inf St-~~] Mim.Metals & Cable Suo Pnrt" P.111nAlA Rnmui-Off Tn'I'AT. Pnt.JRR Pl.ANT :onHII "UKJO; HBICF CSE 623 IUOJ r-l __ ~ CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PRIEI!I'ARED IFOR QUANTITY UII!IT UNIT AMOUNT COSTS 1 000 CY 700 700.000 26 TON 5,100 132,600 (32,600) ll'li" ".l:l ,-~ [~ r -_] tl -~ " L ' t 14879-001 JOB NO NOV 1981 DATE SHEEV 3 OIF 16 TOTALS REMARKS 800,000 51,000,000 r --] ~ ~ ~~~ '---\_____! J --I \~ J.r---- ( _ _j HAJ/APD 14879-001 PREPARED BV JOB NO MF NOV. 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHIEET" 4 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS I "R nAM & WA"!'ERWAYS R ...... ll"vnir W.at-~11" T..sav<Pl R~c-n1rdin" LS 100 000 Tn~.allrll> ~t"r11rhtT~ !':ill"lll> RvnlnTJitinn 'Mnh-t1i'1>At-"inn ILS 150.000 lf'.nT41> nT"i 11 i no 5,000 ILF 80 400~000 11 .. 1 i ll'nnt"ll>r ..: .. ..., ... """ ILS 150,000 TnnnM F.~r..av .. & ~unnnrl:a 12 _t_ooo leY 470 5.640.000 Tunn .. l C'.nnl' & Rt:ainf .~t-.... 100 lcr 350 35.000 l.ak~ ... TAn lJlinal Rnunrf'li ILS 3.000,000 L = 26' D1 .... oa li.." n 'i'amn r.nnll' 600 lev 700 420.000 1'11-ft uri n D r.r """' 60 I DAYS 10,000 600,000 Rnamd:Off 5,000 10,400.000 int-Alr~ Gat.e ~h.11ft" Shaft Exc-av. & Snnnorta_ 10.000 CY 360 3, 600 _t_ 000 Mass Surfac~ Exc~v, 50.000 lr.v 30 1.500,000 n. ~t.e & Rein£ _St.:•<P1 5.700 lr.v 890 5.073 .ooo MiRe-M~t"Al A .l!Ati:•A f. Hni It 244 I TON 12,500 3,050,000 _luumtf-Off_ (23 000) 13.200 000 HAICF CSE 623 13<001 i"ll'liEi"ARED lliY MF ICHECe<tEIO GIY CONCEPTUAL TYPE Of ESTIMATIE At.TEMATlrVE D NO DESCRIPTION ~cess Tunnel et Intake Polr!tel Encav. & Protectio Tunnel Excav & Supports tunnel Cone & Reinf Stee Round4>ff Arraaa Tunnel at Surste Cheml Portal Excav. 6r Protectio1 Ttmnel Excav. 6 ... ~ts T~nnel Cone. 6 Reinf.Steel Groutin.R Cnn~a~t & Pressu Round.-Off I HI!CF CSIE &23 IHOI I '-- I '--~ CHAKACHAMNA HYDROELECTRIC PROJECT er :a PROJECT ALASKA POWER AUTIIORITY PREPARED FOR OUAii!TUTY UNIT UNIT COSTS 6.000 CY 50 72.000 CY 295 200 CY 500 6~000 CY 55 23 000 CY 323 2.300 CY 420 3_400 CF 58 A~OUNT 300_._000 21.240_._000 100~000 (40~000) 330,000 7.429.000 966_,000 197,200 (22.200) r ~ --I 1 ~.._ _________ I --- 1 14879-oon JOB NO NOV. 1981 DATE SHIEIEV 5 Of 16 TOTAlS REMARKS 21~600~000 8.900.000 HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE D NO DESCRIPTION Access Tunnel at Mile 3 5 No 1 Portal Excav & Protection Tunnel Excav & Supports Tunnel Cone & Reinf Steel Grouting-Contact & Pressure Round-Off Access Tunnel at Mile 7 5 No 2 Portal Excav & Protection Tunnel Excav & Supports Tunnel Cone & Reinf Steel Groutimz-Contact & Pressure Round-Off Power Tunnel Excavation & Supports Concrete Groutin2-Contact & Pressure Round-Off H&CF CSE 523 IJ-801 ~ ' r -- ~-' ESnMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 6 000 CY 53 318.000 68.000 CY 297 20,196,000 500 CY 430 2159000 1.125 CF 58 65,250 5.750 6.000 CY 54 324,000 45 000 CY 298 13.410,000 1.600 CY 420 672,000 2.300 CF 58 133,400 (39.400) 67.000 LF 7.698 515.766.000 514.000 CY 334 171.676,000 464.000 CF 54 25,056,000 2.000 TOTALS 2U,BUU,UUU 14,500,000 712,500,000 I I '---- 14879-001 JOB NO NOV 1981 DATE SHEET 6 OF 16 REMARKS .. I L --- HAJ/APD !4879-001 fi'AEPAAIED BV JOB NO MF NOV" 198! CHIECKIED BY OAT IE CONCEPTIJAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHIEIET ] OF 16 TYPIE OF !ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR ~0 DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS RI.':MARKS cosrs SurRe r.hAmhPr -Uooer v-~ •• , lt"inn t.. ~nnnnrt-a 35.500 C"'V 200 7,100,000 Ct !1"11!! & Rll!!inf .~t"PP1 6.100 ("' 880 5.368,000 Ear-L -'ull & Fen~:l no 15.000 r.v 27 405,000 Heliport, Storage, Work Area R_ound-Off 27.000 12,qoo,ooo Penat:ock -T nl" 1 f nll!!il SPr I'" inn v ... ~n .. '\t::!lon & C::nnnnrt-111 23.400 CY 271 6,341,400 Concrete & Reinf Steel 10,500 CY 837 8,788,500 Groutin2 Contact & Pres sure 5.000 CF 52 260,000 ' Round-Off 10.100 I 15,40U,OUO J I Penstock-Horizontal Sectio n & Elbow I );',.., '"""'\tion & Suooorts 14 000 CY 310 4 340--t.900 Concrete S Reinf Steel 6.000 CY 365 2.190.000 Groutin2 -Contact 3.000 CF so 150.000 Round-Off 20.000 ) 6,700,000 HS.CF CSE 623 IHOP ---.I I c~-~-) .. --~ ( J HAJ/APD 14879=001 FAEPAAIED BY JOB NO MF NOV 1982 CHECKED IIV DATE CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTJJAJ. PROJECT SHEET 8 Of 16 TYPE OF IESTIMATIE ALTERNATIVE D ALASKA POWER AUTHORITY l'.lO DIESCRIP'r!ON QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS 'Pi!l!nA~nrk-lolv41> R'i"AnrhPA tn V11 ,1VP C'hamhPT Excavation & Supports 10 000 CY 432 4,320,000 Concrete & Reinf Steel 7.200 CY 608 4~377 ,600 Steel Liner 650 TON 5.000 3~250,000 Grouting-Contact 3,000 CY 50 150,000 Round-Off 2,400 12,100,000 Penstock Between Valve Chao ber & Powerhom e Excsvation & Supports 1 000 CY 440 440.000 Concrete & Backfill 600 CY 550 330.000 Round~Off 30.000 800,000 Draft Tube Tunnels Rock Bolts 61 Grout 19.000 LF 27 513 .ooo Concrete & Reinf. Steel 3.300 CY 425 1.402.500 Round-Off (15.500) 1,900,000 Surge Chamber -Tailrace Excavation & Suooorts 5 000 CY 480 2.400 000 Hl!sCF CSE 523 IJ.80l HAJ/APD 14879-001 PFII!PAAEO BY JOB NO NOV 1981 CHECKED BY IDA TIE CONCEPTIIAJ, CHAKACHAMNA HyDROEI.ECTRTC PRO.IECT PROJECT SHEIE"'' 9 OF 16 TYPE OF ESTIII/lA Tli: ALTERNATIVE D ALASKA POWER AUTHORITY PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Tailrace Tunnel 6J Structurts if".nfF .. ..,..I.am & D~wAtf'!rinll' LS 2,000,000 Port.ml Excav & Protf'!cth In 2.000 CY 65 130,000 f'.nnrrll\t.e _& Rf'!inf Steel 1,200 CY 600 720,000 Ya11n:.rav Br:ldlte LS 65,000 Stonlo~ta & Hoists 81 TON 8,500 688,500 Tmmf'!l Excav. & [!, '":B 25,000 CY 260 6,500,000 Plua J;O, ttion 4,000 CY 50 200,000 Ro~d-Off (3,500) 10,300,000 'J'Af1fi'A<' .. r.l\pnnol r.hann~l ExrAvAit"inn 100)_000 CY 9 900,000 IU..var Trainimr Works River Bed Deepening 50_1000 CY 10 500.000 Mech & Elec LS 5,700,000 TOTAL RESERVOIR, DAM AND W~ TERWAYS 871.600,000 HIIICF CSE 623 IJ.801 HAJ/APD PREPARIED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATIE ALTERNATIVE D NO DESCRI'TION Turbines & Generators Turbines Generators Round-Off A ........ "'sorv Electrical Eouiot ent EClluioment Misc. Power Plant Eouioment Crane Brid2e Other Power Plant Eauio ~wit:chvard Structures Earthworks Concrete & Reinf. Steel Struc Steel & Mise Meta s Round-Off HlsCF CSE 623 (3<801 :_j OUANTITV 4 4 1 15,000 3.800 225 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNIT UNIT AMOUNT COSTS EA 7.970.00 31.880,00( EA 5.660.00 22,640 ,00( (20.00( LS EA 900 ~00( LS 6 .ooo.om CY 25 375,00( CY 640 2 '432 ,00( TON 3,500 787 ,soc 5 .soc 14879-001 JOB NO NOV. 1981 DATE SHEET 10 OF 16 TOTALS REMARKS 300 MW I> 54,500,000 9,000,UUU f>,YUU,UUU 3,600,00f .. -~, I __ j i -1 I L ___ l -I l - HAJ/APD 14879-001 PREPARED BV JOB NO MF NOY. 1981 CHECKED lilY CliAKACHAMNA HYDROELECTRIC PROJECT DATE CONCEPTUAL PROJECT SHEET 11 OF 16 TVPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Swit-... hv~trd Eouioment Tl".anal!. ·a 101) MVA 5 EA l~OIO,.OOC 5,050,000 llni t-& T.fn~ Breakers 7 EA 1Bo,oor 1,260,00() SwH:r!hea I. 1.i oht-n.Arrestc rs 30 EA 3J.OOC 990,000 230 KV CAbl~A 18,000 LF 12C 29160,000 Cnntx:-ols & Metr'R Eauio LS 2,63U 9 UUU 'Rn .. n~ Off 10.000 rz-, nr<r ;umr l'.n...... Sunv Control Eouin LS 1,600,000 I H&CF CSE 623 13-801 J ---I HAJ/APD 14879-001 PREPARED BY JOB NO NOV 1981 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 12 OF 16 TYPE OF ESTIMATE ALASKA POWER AUTIIORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS rt'RAMSPORTATION FACILITIE~ Port Facilities Causeway 19 .600 CY 80 1 568 000 Trestle Piles 50 TON 11.300 565.000 L = 150 LF, !612 11 , t = ~11 Tr~stle Struct. Steel 110 TON 3,500 385JIOOO Trest}.e Reinf Cone. 150 CY 700 105_._000 Facilities -Allowance LS 2,000,000 Round-Off (23 .ooo) 4,600.000 Airport Earthwork 54,500 CY 16 872_._000 Culverts 1.000 LF 65 65,000 Subbase & Base 55 000 CY 14 770.000 Building -Allowance LS 300,000 Round-Off (7 _,000) 2~000,000 H&CF CSE 623 (HOI ,--~~~ \ __ ~) ..., c__l ... ) '~-__ I ESTIMATE SUMMARY HAJ/APD 14879-001 PREPARED BV JOB NO MF NOV 1981 CHECKED illY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEEl" 13 OF 16 VYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS RIEMARC{S COSTS A~>~>aaa i. l'.nnA t:rttr. t: inn RoadE Mi 1'" n...on t-n 1 A+nn li'a~~hunrlr 175,000 CY 6 60 1,155,000 r. .. lv~T~A 1,500 LF 65 97,500 RrtdaeA 1,400 SF 150 210,000 Cool..l.. .. aa I. R~AI2 85,400 CY 15 1~281,000 n ...... .r~ Da-11 1.200 LF 25 30,000 v .. n~ir F.viAII"ino RnAit 95,000 LF 10 950,000 ~nnu v.., ... ,. ... ., 5,000 LF 35 175,000 Rmmd-Off 1,500 ~l,900 ,000 vH ... uu.nn t-n 11\.1.00 v ..... e-l. ........ lr .. 1.465,000 CY 6 60 9_~669~000 Cnlverta 3,600 LF 80 288,000 48"0 CMP Subbas12 & Baae 165,000 CY 15 2,475,000 Guard Rail 13,000 LF 25 325.000 J DDnair F.YiAII"ino Road 16,000 LF 10 160,000 Snnw F12.nr.12.A 1,000 LF 35 35,000 Round-Off 48,000 13,000,000 Mi 1"' 111\~n tn '\Q-4-00 F.Art:hwork 445,000 CY 8 30 3,693,500 lf:nlv12.rta 1,000 LF 80 80,000 48''1 CMP Rrifiog 9,000 SF 150 1,350,000 c .. l..l ....... t. RsaAI2 38,000 CY 15 570,000 C!na.rd Rail 10,000 LF 27 270p000 Snnu ii'Dnl"ii>A 2,000 LF 35 70,000 Dn,.n.rl-nf~ (33,500) 6,000 000 HizCF CSE 623 13-801 L~l (-- I HAJ/APD PREPARED BY MF CHECICIED lll"' CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE D NO OESCRIPTIOI\l ti.Alkv.rAv To Gate Shaft Earthtrorlt Guard Rail Bridae Riorao .Round-Off .a............ Road to Tailrace T1 Earthwork Culverts Subbase & Base Guard Rail Round-Off H&CF CSE 523 IHOI l \ ~) CRAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 1,200 CY 20 24,000 1,000 LF 25 25,000 200 SF 150 30,000 100 CY 35 3,500 17 :soo nnel 56_,000 CY 8 -441J;omr 100 LF 80 8,000 2,500 CY 20 50,000 600 LF 25 ls-,000 (21.000) ----, 14879-001 JOB NO NOV 1981 DATIE SHEE"r 14 OF 16 TOTALS REMARKS 100,000 4H"9'1 CMP ~uu,uuu .. HAJ/APD PREPARED BV MF CHECitED BY ,--~ \ 4 I --~ ES11MATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL PROJECT TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE D PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT COSTS Access Road to Downstream Pc !Wer Tunnel Earthwork 215 000 CY 9 80 2.107.000 Culverts 800 LF 80 64.000 BridRe 3,000 SF 150 450.000 Subbase & Base 10.000 CY 21 210,000 Guardrail 9,000 LF 32 288,000 Snowshed & Slide Fall 1.000 LF 800 800.000 Round-Off (19.000) Temoorarv Construction Roads Earthwork 61.000 CY 6 366.000 Culverts 600 LF 80 48,000 Bridae 3,000 SF 150 450,000 Guardrail 2,000 LF 25 50,000 Round-Off (14.000) Road Maintenance Summer Season 36 MO 120.000 4.320,000 Winter Season 24 MO 480,000 11,520,000 Round-Off (40.000) 'T'OTAT MY~F.~~ 1i. ~l' UN F loAns HQCF CSE 523 13-801 TOTALS 48'/J CMP 3,900,000 900,000 15,800,000 44 100 000 I \ '----=-) 14879-001 JOB NO Nov. 1981 DATE SHEET 15 Of 16 PEMARKS C] HAJ/APD PRIEI'AAED BY MF ' CHECKED BY CONCEP'lWAl!. TYPE OF IESVOMATIE ALTERNATIVE D NO DESCRDPT90N T1ransmission Line Clear & Grub 'Jl'rmvun-ilaAinn Line Submarine Cable Roun«i-Off TOTAL SPECIFIC CONSTRUCTION C OST AT JANUARY 1982 PRICE LEVELS ~QCF CSE 523 13-801 I~ ---.....- CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AU'll'HORITY PREPARED FOR l!liUAI'<!TITV UNOT UNIT AMOUNT COSTS 70 MI ~25.000 15.750 .ooo 70 HI 344 000 24 080 000 21 MI ~92.000 16.632 .ooo 38.000 I~ - - '\l'OTALS 56.500,000 1.117 500.000 I ~ I 14897-001 JOB NO NOV 1981 DAVIE SHEET 16 OF 16 REMARKS ALTERNATIVE E ESTIMATED COST HAJ"/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION POWER PLANT STRUCTURE Valve Chamber & I ~-~1 IMPRC Excavation & Supports Concrete & Reinf Steel ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PRO.IECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT COSTS VEMENTS 10,000 CY 275 6.520 CY 410 AMOUNT 2,750,000 2,673,200 Struc Steel & Mise Meta s 52 TON 1,800 93_,600 Round-Off (16,800) I Underground Powerl!_ouse Dewatering LS 4,100,000 Excavation & Supports 58.900 CY 168 9,895,200 Drilling-Percus.& Rotary 12 700 LF 27 342,900 Concrete & Reinf Steel 13 100 CY 630 8,253,000 Struc Steel & Mise Metals 300 TON 5 300 1,590,000 Architectural LS 1,000,000 Round-Off 18,900 Bus Galleries Between Power house & Transformer Vaults I:xcavation & Supports 200 CY 825 165,000 Concrete 120 CY 290 34,800 Round Off 200 -H!&CF CSE 623 13-601 • 14879-001 JOB NO NOV 1982 DATE SHEET 1 OF 20 TOTALS REMARKS 5,500,000 Ent1re UnderRround Complex 2"-3"~ 25,200,000 - \ 200 .000 1~1 l -~ 7 HAJ/ APD ESTIMATE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 2 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Transformer Gallerv & Tunne 9 Excavation & Supports 11.960 CY 290 3.468.400 Concrete & Reinf Steel 830 CY 460 381.800 Struc Steel & Mise Metals 120 TON 3,800 456.000 Round Off (6 .200) 4,300,000 Valve Chamber & Transformer Gallery-Access Tunnels Excavation & Supports 1,500 CY 250 375.000 Concrete 60 CY 290 17.400 Round-Off 7.600 400,000 Powerhouse Access Tunnel Portal Excav.& Protection 56,000 CY 10 560.000 Portal Cone.& Reinf Steel 1,000 CY --s-70 570,000 Tunnel Excav & Supports 24,000 CY 300 7.200.000 Tunnel Concrete 900 CY 290 261.000 Tunnel Mise Metals 30 TON 11.000 330,000 Subsurface Exploration Mobilization LS 1,500,000 Exploratory Adit 1,000 LF 1.800 1,800,000 Core drilling 5,000 LF 140 700,000 Helicopter Service LS 600.000 Round-Off (21.000) 13 500 000 H&CF CSE 623 (3-801 -~ i I ESTIMATE SUMMARY HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 3 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Cable Wav r.nnl'r~t~ I. R~inf St~~l 1,000 CY 700 700,000 Mi At:: Me tsls & Cah le _Sup. 26 TON 5,100 132,600 Port: P::~nPl A Round-Off (32 ,600) 800,000 \ _TOTAl. POUF.R PT.AN'l' s· 'Hill :TiffiF. TMPR1 IVEI'ofEN"'S 49 ,_900 _,000 H&CF CSE 523 I:J-80) - HAJ/APD ESTIMATE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 198? CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 4 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT COSTS AMOUNT TOTALS REMARKS ITR DAM 1.. WATERWAYS u ............. ,.f .. u .... ,...,. T.PvPl R~~>t"nrdinl7 LS 100.000 Tnt-alrP St"Tnrt-nrP ~ ...... ll'vnln,."'f"ii"Jn M...,hili,.nt-inn T.S 150.000 1"...,,..,. Tlri 11 inB 5.000 T.F 80 400.000 lti<>l i l'nn .. .,.,. ~ ........ .f ,.,.. T.S 150.000 'l'uY1nP1 ll'vr::nr 1. Sunnnrt"a 10.000 'cv 510 5,100,000 ~ '1' .. .,...,,..] f'.nn,. 1. RPinf St-1<>11> 90 r.v 350 31.500 T ... lra-'l'an (Fin<~ 1 Rnnnrl) T.S 2,500,000 L 26' 'Dlfti'O 1. n 'l'omn (",....,.,. 550 r.v 700 3R5 000 . ni nina r. ... ,....., 60 DAYS 10,000 600,000 Rnuntl-Off (16,500) 9,300,000 ------=--1=~ -~-==-r ------ ---------------------------------l ----------------------- H&CF CSE 623 13-60) r-..., .. C' ... -~ h " ( \__~ I J -=-- a@ !ESTIMATE SUMMARY 14879-001 HAJ PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CHAKACHANMA HYDROELECTRIC PROJECT CONCEPTUAL PROJECT SHEET 5 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Intake Gate Shaft Exca'Lation & ~nnnnrtl'l 1no T.l<' 17 soc 6 300 000 Mass Surface Excavation 50 000 CY 3C 1 500 000 Concrete & Reinf ~tf>f>l 5 200 CY 89C 4 628 000 Mise Metals. Gates & Hois 220 TONS 12 20( 2 684 000 Access Road 1 25 MI .000 0 DO 2.500 000 Round Off (12.000) 17 600 000 H&CF CSE 523 (3-80) r-' ;;------\ r -' - EST~ATE SUMMAIRV RAJ 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 6 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Fish Passage Facil1ties Approach Channel Channel Excavation 1.040.000 CY 11 30 11.7 52.000 Slope Protection 90.000 CY 28 00 2 520.000 Round (22 .000) 14.250,000 Upstream Portal Excavat1on 1n Rock 64 500 CY 30 00 1.935.000 Rock Bolts -Ch LK Mesh LS 544.500 Dewatering Durmg Construct LS 50.000 Fence 400 LF 45 00 18 000 Round 2 500 2 550 000 \ H&CF CSE 523 (3-80) '- I~ I ' -J ESTIMATIE SUMMAAV RAJ 14879-001 PREPARED BY JOB NO MF NOV. 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 7 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTIRNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS ~~stream Fish Passage Facilit' Excavat1on & Support 16,550 CY 163 2,697,650 Concrete & Reinf Steel 5 880 CY 759 4,462,920 Mise Metal, Gates & Crane LS 1,786,300 Electr1cal & Instrumentat1or LS 200,000 Round Off (3 '130) 9,150,000 Downstream Fish Passage Facility Excavat1on & Support 8,900 CY 191 1.699 900 Concrete & Reinf Steel 2,600 CY 635 1,651,000 Mise Metal. Gates & Crane LS 2,283,000 Electrical & Instrumentatior LS 100,000 Round Off (3, 900) 5,730,000 Access Tunnel Excavat1on & Support 122,500 CY 303 37,117,500 Concrete & Reinf Steel 22.800 CY 573 13.064,400 M1SC Metal LS 405,000 Electr1cal -Lighting LS 231,000 Round Off (7 ,900) 50 810 000 H&CF CSE 523 (3-80) J-J I -I 1-,-_ _; I ' __ __) fESTiMATE SUMMARY RAJ 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE SHEET 8 OF 20 CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS F1sh Passa11:e Facilities Excavat1on & Sunnort 6 600 CY 53 349 800 Concrete & Re1nf Steel 740 CY 778 57 5 720 Mise Metal Gate etc LS 434 650 Round Off (170) . 1 360.000 Chakachatna R1ver Flow Regulat1on R.1.ver Bed Deepenrng 10 000 CY 9 5( 95.000 Rip-Rap 1 000 CY 35 oc 35 000 130,000 Access Road LS 300,000 Access Tunnel to Fish Passage Facilities Portals Excavat1on 700 CY 93 65.100 Tunnel Excavation & Sunnort 3 350 CY 314 -_}_,_Q_~1_, 90_9 Round Off 3,000 1 120 000 Total Fish Facilities 85 400 000 H&CF CSE 523 (3-80) \ f J ' - HAJ PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION Chakachata Dike and Spillway Excavat1on & Slone Protecti Concrete & Reinf Steel T11nber Bridge Dike Round Off ,- 1 on Access Tunnel at Surge Chamber Portal Excavation & Protect ion Tunnel Excavation & Suooorts Tunnel Concrete & Reinf St eel Grouting Contact & Pressure Watertight Bulkhead & Frame Round Off H&CF CSE 523 (3-80) mil ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 280 000 CY 29 50 8 260 000 1 100 CY 325 357 500 2 200 SF 150 330.000 250 000 CY 0 75 187.500 ( 35.000) 6.000 CY 35 210.000 14.000 CY 317 4.438.000 1 700 CY 420 714 000 2.260 CF 58 131.080 27 TON 13.800 372.600 34.320 ----l ( ~ --~ ( ~ I --'"' (- -J \ --I I -I 14879-001 JOB NO NOV 1982 DATE SHEET 9 OF 20 TOTALS REMARKS 9,100,000 5,900,000 r I - !ESTiMATE SUMMARY HAJ/APD 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 10 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Power Tunnel TBM Excavation & Supports 53 400 LF 6,110 326,274,000 Concrete 267 000 CY 341 91 047 000 Grouting 540 000 CF 56 4( 30 456 000 Round Off 23.000 447 800 000 H&CF CSE 523 (3-80) HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION Surge Chamber -Uooer Excavat1on & Suooorts .-- 1 Concrete & Reinf Steel Earthwork & Fencing Round Off Penstock -Hor1zontal Sect1on Excavation & Supports Concrete & Remf Steel Grouting -Contact Round Off H&CF CSE 523 (3-80) r ' EST~ATIE SUMMARY 14879-001 JOB NO NOV 1982 DATE CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 11 OF 20 ALASKA POWER AUTI-IORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS 27 100 CY 353 9 566 300 10 000 CY 893 8 C)30 000 15.000 CY 27 405 000 \ __/ ( 1 300) 18.900 000 12 000 CY 334 4 008 000 5 100 CY 365 1,861,500 2,600 CF 50 130.000 500 6,000 000 , l \ ~) HAJ/APD ESTIMATE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAl. CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 12 OF 20 TYPE OF ESTIMATE ALTERNATIVE E AI..ASKA PQWER AUTHORITY PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT COSTS TOTALS REMARKS P~nAt-n,.lr-t.ru#> R ... t~nf'h<>a t-n U~ :1 ve Chamber Excavation & Suooorts 9 000 CY 480 4.320.000 Concrete & Reinf Steel 6.100 CY 608 3.708.800 Steel Liner 700 TON 5 000 3.500.000 Grouting-Contact 7.000 CY 56 392,000 Round-Off (20.800) 11,900,000 Penstock Between Valve Chan ber & Powerhom e Excavation & Suooorts 850 CY 440 374.000 Concrete & Backfill 500 CY 550 275 000 Round-Off (49.000) 600,000 Draft Tube Tunnels \ Rock Bolts & Grout 15 .ooo LF 29 435,000 Concrete & Reinf Steel 2.975 CY 425 1,264,375 Round-Off 625 1,700,000 Sur2e Chamber -Tailrace Excavation & Suooorts s.ooo CY 480 2, 400_, 000 H&CF CSE 523 (3-601 I __ --) HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAl. TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION Tailrace Tunnel & StructurEs Cofferdam F. DPwRt~rin~ Portal Excav. & Protecti<n C.oncrete & Rein£ Steel Walkwav Bride.e Stoololls & Hoists Tnnn~l Excav & " ·ts Pluo Excavation Bnnnd-Dff Tai 1 T.<l N> r.h.c~nnP 1 Ch111nn~l Exr_Rvat:inn Biv~r Traininll Works River Bed Deepening Mech & Elec -' ' I r ~J ESTIMATE SUMMARY CHAKACHAMNA HYDROET.ECTBTC PBO.JECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS LS 2,000,000 2~000 CY 65 130,000 1.200 CY 600 720,000 LS 65,000 81 TON 8,500 688,500 20.000 CY 290 5,800,000 4,000 CY 50 200,000 (3 ,500) 80,000 CY 9 720,000 (20,000) 50,000 CY 10 LS TOTAL RESERVOIR, DAM AND WJ TERWAYS H&CF CSE 623 13-80) 14879-001 JOB NO NOV 1982 DATE SHEET 13 OF 20 TOTALS REMARKS 9,600,000 700,000 1 500,000 6 '100 ,000 1113 60f) flOfl I - HA.I/ APD ESTIMATE SUMMARY 14879-001 PREPARED BY JOB NO MF NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 14 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS COSTS REMARKS Turbines & Generators 330 MW Turbines 4 EA 8;-480,00( 33,920,000 Generators 4 I: A 6,00(\001 24,.000,000 Round-Off (20,000) 57,YOO,OOO Accessorv Electrical Eauio11 ent Eaui~ment LS Y,:>uu,uuu Mise Power Plant Eauiomen Crane Brid2e 1 EA 930,000 Other Power Plant Eauio LS 6.370.000 7,300,000 Switchvard Structures Earthworks 15.000 CY 25 'JTS,OOO Concrete & Reinf Steel 3,800 CY 640 2.432.000 Struc Steel & Mise Meta s 225 TON 3,500 787.500 Round-Off 5.500 3,600 000 1 H&CF CSE 623 IJ.801 ( --f -~- L--I HAJ/APD PREPARED BY CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION Switchvard EouipJII.ent Transformers 105 MVA Unit &.Line Breakers Switches & Li!:!htn Arrestc 230 KV Cables Controls & Metr'~ :Cquip Rnuntf Off (' rnnmun l cat 1J:Ln and Sunv r.nnl:"rnl En· tin H&CF CSE 623 I:HJOI \ ,~- 1 I \.__ ~' -~ --.1 I ESTIMATE SUMMMY CIIAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT COSTS 5 EA ~030,00( 5,150,000 7 EA 185,00 J 1,295,000 rs 30 EA 34,00) 1,020,000 18,000 LF 130 2,340,000 LS 2,700,000 i_5,_000)_ LS TOTALS 12,500,000 ' 1,600,000 I '-----) 14879-001 JOB NO NOV 1982 DATE SHEET 15 OF 20 REMARKS ~-~ ~~-J HAJ/APD PREPARED BY - I r -I ~I ESTIMATE SUMMARY • r -1 '-- 14879-001 JOB NO NOV 1982 CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 16 OF 2() TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS [RANSPORTATION FACILITIES Port Facilities Causeway 19.600 CY _80 1.568.000 Trestle Piles 50 TON 11 300 565.000 L = 150 LF ~12". t = !.," Trestle Struct Steel 110 TON 3 500 385 000 Trestle Reinf Cone 150 CY 700 105.000 Facilities -Allowance LS 2 000 000 Round-Off (23.000) 4.fi00.00 Airport Earthwork 54 500 CY 16 872,000 Culverts 1 .000 LF 65 65,000 Subbase & Base 'l'l ()()() CY 14 770,000 Building -Allowance LS 300,000 Round-Off (7,000) 2,000.000 H&CF CSE 623 13-801 HAJ/APD PREPARED BY F CHECKED BY CONCEPTUAL TYPE OF ESTIMATE ALTERNATIVE E NO DESCRIPTION At".ceRa & Construction Roade Mil P f\+.00 t-n 1 R.J.OO F.~rt-hwnrk CtLl vert:a_ Brido:es SnhhstRe & BaRe r.u .. rr'l R<ail RPnstir ExiRtino: Road _Snnw _Fences Round-Off MilE> lR+OO_tn':\5-HlO F.~trt"hwnrkR _Culv~rta .Suhbf!Re & Base Guard Rail Renair Existimz Road Snow Fences Round~Off -' Mile 35+00 to 39+00 F.strthwnrk CulvertR _Brj_do:e.. ..S: thh:HU:'! F. R:Hif'! r.mt ret R;t i 1 SnowFenrPR Rnunri-Off H&CF CSE 523 (3-801 ,___] I '~ ESTIMATE SUMMARY \_~-- CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT ALASKA POWER AUTHORITY PREPARED FOR QUANTITY UNIT UNIT AMOUNT TOTALS COSTS 175 000 (';'{ 6.60 1.~5.000 1,500 LF 65 97 500 1,400 SF 150 210 000 85,400 CY 15 1 281 000 1 200 LF 25 30.000 95,000 LF 10 950 000 5.000 LF 35 175 OOQ 1 500 3 90Q.QOO 1_J465 000 CY 6 60 9 669 000 3,600 LF 80 288 000 165,000 CY 15 2 475 000 13,000 LF 25 325,000 16 000 LF 10 160 000 1,000 LF 35 35 000 48,000 13 000,000 445,000 CY 8 30 3_.693 500 1,000 LF 80 80,000 9,000 SF 150 1_.350 000 38,000 CY 15 570 000 10,000 LF 27 270,000 2,000 LF 35 70 000 (33 .500) 6.oon non _j 36"0 CMP 48"!ll CMP 48"0 CMP ,--, I~ 14879-001 JOB NO ~~J DATE SHEET 17 OF 20 REMARKS HAJ/APD PREPARED BY MF CHECKED BY CONCEPTUAL TYPE OF ESTIMATE I_--I I 1 '-~ ALTERNATIVE E NO DESCRIPTION Walkwav To Gate Shaft Earthwork Guard Rail BridRe Riorao Round-Off Access Road to MacArthur Earthwork Culverts Brid2e Imorovements Subbase & Base Guard Rail Snow Fences Round-Off Access Road to Tailrace F..arthwork Culverts SuhhaRe & Base Guard Rail Round-Off H&CF CSE 523 IJ.80) ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT QUANTITY 1.200 1 000 200 100 Valley 545 000 2 400 9.000 105.000 6.000 3.000 ~unnel 56.000 100 2.500 600 PROJECT ALASKA POWER AUTHORITY PREPARED FOR UNIT UNIT AMOUNT COSTS CY 20 24.000 LF 25 25.000 SF 150 30.000 CY 35 3.500 17.500 CY 7 3.815 .ooo LF 75 180,000 SF 70 630,000 CY 15 1.575.000 LF 25 150,000 LF 35 105.000 45,000 CY 8 448.000 LF 80 8,000 CY 20 50,000 LF 25 15,000 (21,000) 14879-001 JOB NO NOV. 1QR2 DATE SHEET 18 OF 20 TOTALS REMARKS 100,000 36"!11 and 48"!11 CMP 6,500,000 4R't/J CMP 500,000 -I RAJ /APD PREPARED BY MF CHECKED BY I I ESTIMATE SUMMARY CHAKACHAMNA HYDROELECTRIC PROJECT CONCEPTUAL PROJECT TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT COSTS Access Road to Downstream p, ~Wer -Tunnel. Earthwork 215,000 CY 9 80 2,107,000 Culverts 800 LF 80 64,000 Bridge 3,000 SF 150 450,000 Subbase & Base 10,000 CY 21 210,000 Guardrail 9,000 LF 32 .288;DOU Snowshed & Slide Fall 1,000 LF 800 800,000 Round-Off (19!000) Temporarv Construction Road~ Earthwork 61,000 CY 6 -300,000 Culverts 600 LF -sn 48.000 Bridge T,OOO SF T50 450,000 Guardrail 2,000 LF ~5 50,000 Round-Off (14.000) Road Maintenance Summer Season 45 MO 150,000 6,750,000 Winter Season 30 MO 1600,000 18,000,000 Round-Off so.ooo ITOTAl Ar.r.R~~ F. r.oN~'T'RTTr.'T'ION ROi los HlitCF CSE 523 IJ-801 ( - J 14879-001 JOB NO NOV 1982 DATE SHEET 19 OF 20 TOTALS REMARKS 48"¢ CMP J,~uu,uuu 48"!6 CMP 900,000 24_,800 ,000 59,600,000 __.J.;: 'At!~~ I --1 ) \~.., I I --/ ___ ! l_j r l_ __ ___ I • ESTIMATE SUMMARY HAJ[APD 14897-001 PREPARED BY JOB NO MF CHECKED BY DATE CONCEPTUAL CHAKACHAMNA HYDROELECTRIC PROJECT PROJECT SHEET 20 OF 20 TYPE OF ESTIMATE ALASKA POWER AUTHORITY ALTERNATIVE E PREPARED FOR NO DESCRIPTION QUANTITY UNIT UNIT AMOUNT TOTALS REMARKS COSTS Transmission Line _Clear & Grub 82 MI 225,000 18,450,000 Transmission Line 82 MI 343,000 28,126,000 Submarine Cable 21 MI 792,000 16,632,000 Round-Off (8 2000) . ()_.1_, zuu, uuu _f TOTAL SPECIFIC CONSTRUCTION COST AT JANUARY 1982 PRICE LEVELS go_s,3oo,ooo H&CF CSE 623 13-801