Casad Dam

Casad Dam is a concrete arch dam in Bremerton, Kitsap County, Washington), built starting in 1955 and completed in 1957.[6][7]

Casad Dam
Casad Dam (near center) and Union River reservoir
Location of Casad Dam in Washington (state)
Country	United States
Location	Bremerton, Washington
Coordinates	47°32′17″N 122°46′47″W
Purpose	Municipal water supply[1]
Status	Operational
Construction began	1955
Opening date	1957
Construction cost	$1.4 million[2]
Owner(s)	City of Bremerton
Dam and spillways
Type of dam	Concrete arch
Impounds	Union River
Height	190 ft (58 m)
Length	416 ft (127 m)
Elevation at crest	643.7 ft (196.2 m)
Width (base)	56 ft (17 m)
Reservoir
Creates	Union River Reservoir
Total capacity	1,400,000,000 US gal (5,300,000 m3)
Catchment area	3,000 acres (1,200 ha)
Surface area	40 acres (16 ha)
Normal elevation	607 ft (185 m)[3]
Coordinates from USGS,[4] specifications from factsheet[5] unless noted

The dam is Kitsap County's only major water diversion structure,[8] impounding Union River to form a reservoir that is the source of over half of Bremerton's municipal water supply.[5] The water is gravity fed from the reservoir at 607 feet (185 m) in the hills[3] to the city, most of which is at or near sea level.[9]

Bremerton owns 95% of the land in its 3,000-acre (1,200 ha) watershed, and the Union River reservoir behind Casad Dam holds 1,400,000,000 US gallons (5,300,000 m³) of water.[6] The city is unusual in drawing most of its water supply from an open air source, the reservoir, which can occasionally be affected by algal blooms.[10]

The dam's intake tower underwent seismic retrofit in 2012 to withstand a 0.78 g peak acceleration in a maximum credible earthquake from the Seattle Fault which runs about four miles (7 km) away, on the north side of Green Mountain.[11][12]