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Wynoochee River Project


Wynoochee Dam began generating electricity in 1994

Tacoma Power created the Wynoochee Hydroelectric Project in 1994 by adding a hydroelectric facility to the U.S. Army Corps of Engineers' Wynoochee River dam.

The dam, owned by the City of Aberdeen, is located in the foothills of the Olympic Mountains in Grays Harbor County. In 1972, it was built by the Corps of Engineers to provide flood control, industrial water storage for the City of Aberdeen, and water irrigation. It also supports the river's fishery.

Tacoma Power built a powerhouse one-quarter mile downstream from the dam. The powerhouse began generating electricity in 1994 and produces about 30 million kilowatt-hours of electricity each year, enough to serve 2,100 Northwest homes.

Take a Tour
Free group tours at the Wynoochee River Project are available. Tours are available by appointment to school, civic, business and recreational groups during regular working hours. To make arrangements for a tour, call Tacoma Power at (253) 502-8759.


Statistics

  • Year completed - dam, 1972; powerhouse, 1993
  • River system - Wynoochee
  • Original investment - dam, $24 million; powerhouse, $25 million
  • Type of dam - concrete gravity and embankment
  • Height - above riverbed, 175 feet; above bedrock, 175 feet
  • Length - 1,028 feet
  • Width - top, 20 feet; base, 146 feet
  • Volume of concrete in dam - 92,800 cubic yards
  • Average flow - 534 cubic feet/second
  • Drainage area - 41 square miles
  • Reservoir length - 4.4 miles
  • Miles of shoreline - 13 miles
  • Reservoir area at maximum elevation - 1,140 acres
  • Reservoir elevation - full, 800 feet; lowest allowable, 700 feet
  • Average annual generation - 30 million kilowatt-hours
  • Equivalent number of NW homes served - 2,100
  • Number of generators - One, 10,800 kilowatt
  • Installed capacity (nameplate rating) - 10,800 kilowatt