Wynoochee River Project

Tacoma Power created the Wynoochee River Project in 1994 after building a powerhouse a quarter mile downstream from the Wynoochee Dam. The project generates enough clean, renewable hydroelectric energy to serve about 2,500 homes.

Completed in 1972, the Wynoochee Dam is owned by the city of Aberdeen and is located in the foothills of the Olympic Mountains in Grays Harbor County. It was built by the U.S. Army Corps of Engineers to provide flood control, irrigation and industrial water storage for Aberdeen. The dam formed Wynoochee Lake.

Project Licensing

All four of our hydroelectric projects are licensed separately by the Federal Energy Regulatory Commission (FERC), which was created by the Federal Power Act to ensure safe and efficient operation of power plants across the U.S. Many other agencies, tribes, organizations and stakeholders are also an important part of the licensing process.

Fish and Wildlife Programs and Public Recreation

Along with generating clean, renewable hydroelectric energy, our FERC license includes mandates for:

  • Operating a fish collection facility 2 miles downstream from the dam. There, a low barrier dam and a series of pools divert returning adult fish to a large holding pool where salmon and steelhead are separated from other species. Some are kept for brood-stock while the rest are loaded into a tank truck and hauled 5 miles upstream, past Wynoochee Lake, where they are released into the river to spawn.
  • Contracting with the Washington Department of Fish and Wildlife to enhance 1,000 acres of high-quality forage area for Roosevelt elk.
  • Providing public outdoor recreation around Wynoochee Lake including camping, fishing, boating, hiking, mountain biking and day use.
  • Learn more about our wildlife programs.
Take a Tour

Free group tours of the Wynoochee River Project facilities are available by appointment for school, civic, business and recreational groups during regular working hours. To make arrangements for a tour, please complete our request form.

  • 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 – 32 million kilowatt-hours
  • Equivalent number of NW homes served – 2,500
  • Number of generators – one 12,800 kilowatt generator
  • Installed capacity (nameplate rating) – 12,800 kilowatts