Fact Sheet: Bremerton's Casad Dam
Casad Dam is located approximately 10 miles from downtown Bremerton in a protected watershed. The dam is a concrete arch structure completed in 1957. It is owned and operated by the City of Bremerton to impound the Union River for the City's drinking water supply. Downstream of Casad Dam is McKenna Falls, which provides a natural barrier to migratory fish. The City provides an environmental benefit by protecting water quality and ensuring downstream fish flows.
When full, the Union River Reservoir holds over a billion gallons of water and supplies about 60% of the City's drinking water during years with normal precipitation. Casad Dam is one of Bremerton's most remarkable and valuable investments.
Specifications
- Height: 130 feet from ground level
- Length 416 feet
- Elevation at top: 643.7 feet above sea level
- Thickness at base: 56 feet
- Drainage Area: 3,000 acres
- Surface area at crest: 40 acres
- Water storage at crest: 1.4 billion gallons
Dam & Water Use
Use of Casad Dam is regulated by the Washington Department of Ecology Dam Safety Section in accordance with state law. Ecology's directive is to reasonably secure safety to life and property by assuring that dams are properly designed, constructed, operated and maintained. Dam engineers regularly inspect Casad Dam. Engineering analysis concludes that the dam is well constructed and maintained and that the basalt rock that supports the dam is stable. Casad Dam can handle stresses very well and has adequate strength under flood and earthquake conditions.
The purpose of the dam is solely for water supply. There is now power generation. Although the dam is not operated for flood control, high flows from early winter storms are attenuated by the dam.
The City of Bremerton Operation and Maintenance Manual and Emergency Action Plan describe procedures to minimize damage and alert emergency responders and downstream residents of any problems. Bremerton ensures reliability of Casad Dam through responsible operation and maintenance, regular inspections, and coordinating with dam safety officials and local emergency management personnel in both Mason and Kitsap County.