Chakachamna Hydropower

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Chakachamna Hydropower

• TDX Power
• Nicholas Goodman
• Eric Yould
• for
• Alaska Forum on the Environment
• February 13, 2008

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Inventory of Alaska Hydropower Potential

• U.S. Bureau of Reclamation
• U.S. Army Corps of Engineers
• 256 sites with continuous power greater than 2500
  KW
• 192 billion KWH energy potential
• 40 of the United States untapped hydropower

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Potential Major Alaska Hydropower Projects
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Existing Hydropower Statewide

• 40 projects
• Most located in Southeast

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Existing Hydropower Southcentral

• Eklutna 37.5 MW
• Bradley Lake 115 MW
• Cooper Lake 20 MW

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Susitna Project Location
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Upper Susitna Dam Sites
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Susitna Four Dam Scheme
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Devil Canyon Watana
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Watana Site Layout
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Devil Canyon Site Layout
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Results of Screening Process
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Alternatives Outside the Susitna Basin
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Hydro Alternatives
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Chakachamna Hydropower Investigations
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Chakachamna Hydro Power

• Studied by Alaska Power Authority in early 1980s
• Divert stream flow from Chakachatna River to a
  powerhouse on the McArthur River by way of a 10
  mile 25 foot diameter power tunnel
• Minimal dam on Chakachamna Lake
• Installed capacity of 330 MW, generating 1.6
  billion KWH annually
• Total cost of project in 1980 dollars 1.0
  billion
• Project is 40 miles from Chugach Electric power
  facilities at Beluga

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Chakachamna Project Location
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Chakachamna Aerial View
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Chakachamna Dam Site
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Power Plant Site
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Chakachamna Selected Plan
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Chakachamna Lake Tap Gate Shaft Inflow to
Power Tunnel
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McArthur River Underground Powerhouse
(Chakachamna)
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Chakachamna Lake Outlet Plan
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CHAKACHAMNA FISHERIES

• 5 species of salmon use the basin
• Sockeye the main salmon species
• Dolly Varden ubiquitous in the streams
• Lake trout observed in lake
• Not a large anadromous fishery but worthy of
  protecting
• Fish ladders at lake outlet required
• Possible temperature enhancement to river

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1982 FISH INVESTIGATIONS
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CHAKACHAMNA WILDLIFE

• 56 species of birds
• 16 species of mammals
• Moose, wolves, lynx, bear, wolverine, other fur
  bearers
• None on the endangered species list
• Less impact than other hydro projects of similar
  size

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Chakachamna Wildlife
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Geotechnical Considerations

• Seismic Castle Mountain Fault
• Volcanic Mount Spurr (1992 1953 eruptions)
• Glacial Barrier, Blockade, McArthur, Shamrock

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Geotechnical Overview
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CHAKACHAMNA DAM SITE
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CHAKACHAMNA DAM SITE
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MT. SPURR GEOTHERMAL
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BARRIER GLACIER
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KENIBUNA LAKE
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McARTHUR RIVER POWERHOUSE SITE
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McARTHUR RIVER UNDERGROUND POWERHOUSE
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SUSITNA CHAKACHAMNA COMPARED
Susitna Chakachamna
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SUSITNA CHAKACHAMNA COMPARED
Susitna Chakachamna
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Next Steps