Powered by water: The electricity powering your home is 97% carbon free thanks to hydropower

For over 135 years, hydropower has powered this nation with clean, renewable energy. In recognition of hydropower’s contributions to America’s energy grid, Tacoma Public Utilities (TPU) is excited to celebrate National Hydropower Day on Aug. 23.

Hydroelectricity is the original Northwest renewable resource. We store water from rivers, melting snow, and rainfall in reservoirs behind our dams; when we  release it, it passes through turbines to generate electricity. On rivers that have multiple dams, water gets reused over and over as it moves downstream. Our largest source of generation is hydropower from seven dams along four rivers in Western Washington.

Our hydroelectric projects generate about three billion kilowatt hours of electricity each year. Our projects include:

As part of our responsibility for operating our hydro projects, we support major fish and wildlife programs, protect more than 20,000 acres of wildlife lands, operate four excellent parks, and offer other recreational opportunities.

With the help of our hydro projects, we are able to provide power to our customers that is 97% carbon free.


The National Hydropower Association created National Hydropower Day to celebrate hydropower’s undeniable contributions to America’s clean energy infrastructure, electrical grid resiliency and reliability benefits and environmental protections. As a renewable resource that integrates other renewables, like wind and solar onto the grid, hydropower plays a critical role in America’s future.

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