Alder Dam
Alder Dam stores water in Alder Lake, the largest reservoir in the Nisqually River Project. Water released from the lake passes through the Alder Powerhouse to generate renewable electricity before continuing downstream to LaGrande Dam.
The dam and powerhouse have been part of Tacoma Power’s generating system since 1945 and generate enough renewable electricity to serve approximately 18,000 Northwest homes each year.
Alder Lake Park provides recreation access along the reservoir for camping, boating, swimming and other activities.
Questions? Reach out to Nisqually@tacoma.gov.
At a Glance
- Dam type: Concrete arch-gravity and embankment
- Completed: 1945
- Height: 330 feet above bedrock
- Length: 1,600 feet
- Reservoir: Alder Lake
- River: Nisqually River
- Powerhouse: Alder Powerhouse
- Generators: Two
- Installed capacity: 51,000 kilowatts
