Definition The Cowlitz Falls Dam is a hydroelectric dam located on the Cowlitz River in the U.S. state of Washington.
Overview Completed in 1994, the Cowlitz Falls Dam is situated in Lewis County, approximately 40 miles northeast of Castle Rock. It is operated by Tacoma Power, a division of Tacoma Public Utilities. The project was developed as part of efforts to increase hydroelectric capacity in the region while incorporating modern environmental safeguards. The dam is located downstream of the Mossyrock Dam and forms a relatively small reservoir used primarily for power generation.
Etymology/Origin The name "Cowlitz" originates from the Cowlitz people, a Native American tribe indigenous to the region. The term is believed to derive from the Upper Cowlitz phrase meaning "river of shifting banks" or "capturing the river," reflecting the characteristics of the Cowlitz River.
Characteristics The Cowlitz Falls Dam is a concrete-faced rockfill dam standing approximately 380 feet (116 meters) high with a length of about 820 feet (250 meters). It houses a single generating unit with a nameplate capacity of 90 megawatts (MW). The dam includes a natural fish passage system, specifically a trap-and-haul facility for salmon and steelhead, to mitigate impacts on fish migration due to its location below the impassable Mayfield Lake.
Environmental and regulatory considerations were central to the dam’s design and operation. The Federal Energy Regulatory Commission (FERC) issued a 50-year operating license for the project in 1990, contingent on compliance with fish passage and streamflow requirements.
Related Topics
- Cowlitz River
- Hydroelectric power in Washington State
- Tacoma Power
- Mossyrock Dam
- Fish passage and dam construction
- Federal Energy Regulatory Commission (FERC) licensing
The Cowlitz Falls Dam represents a modern approach to hydroelectric development, balancing energy production with ecological conservation.