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Dams & Our Power Sources

Mayfield Dam

We serve nearly 179,000 customers within Tacoma Power's service area, which stretches across Tacoma to University Place, Fircrest, portions of Fife, Lakewood, Federal Way, Steilacoom, Joint Base Lewis-McChord, other portions of Pierce County as far south as Roy.

We use various sources of generation to keep our service territory moving. Our largest source of generation is hydro power from our seven dams on four rivers in Western Washington.

Learn about our hydro licenses with the Federal Energy Regulatory Commission

Check out our award-winning invention for cleaning moss off our dams and view the video.

Since we own hydroelectric dams, we also offer parks and recreation to the general public. Check out some great places to fish, camp and relax.

Watch a video about America's clean, renewable hydropower.


2017 Source Report
National Hydropower Association

Tacoma Power produces or buys electricity from a number of different resources. We are providing you with information about the fuel used to generate the electricity you used in 2017, the most recent numbers available.

The State of Washington requires that electric utilities provide this information to customers on a regular basis. The Washington State Department of Commerce, Energy Office, publishes the information, based on reports from electric utilities.

Our Power Sources in 2017

Fuel Type Percentage Used
Hydro Power 85.2%
Nuclear* 4.6%
Coal* 1.2%
Natural Gas* 1.6%
Wind 5.5%

Less than 2% can include other sources such as biomass, petroleum, and waste. 

*Represents a portion of the power Tacoma Power gets from the Bonneville Power Administration. 

Integrated Resource Plan

Our Integrated Resource Plan (IRP) helps us assess a portfolio of available generation and conservation resources. The IRP analysis helps us ensure we have sufficient power resources to meet your long-term needs.

Visit our Integrated Resource Plan Page to learn more.