In 1994, Tacoma City Light taps the Wynoochee River in the Olympic Mountains for hydroelectricity. The U.S. Army Corps of Engineers built a flood-control dam there in 1972. Tacoma invested $25 million in a generating station that produces 30 megawatts of electricity, enough to power 2,600 homes.
By 1970, large-scale hydroelectric projects like the Nisqually and Cowlitz projects had been completed. Environmental concerns and the shortage of good sites meant that no more big dams would be built. Tacoma City Light looked at existing flood control and irrigation dams to see if they were suitable for adaptation. One source was as close as the water system. A turbine was inserted into a city water pipe and it generated enough electricity for 300 homes.
The U.S. Army Corps of Engineers had built Wynoochee Dam to control flooding and irrigation in Grays Harbor County. City Light built a powerhouse about a quarter mile downstream and took over operation of the dam. The Corps of Engineers took control of water releases during heavy rains.
