Crystal Springs Dam

Crystal Springs Dam
Official nameLower Crystal Springs Dam
LocationSan Mateo County, California
Coordinates37°31′43″N 122°21′44″W / 37.5285°N 122.3622°W / 37.5285; -122.3622
Opening date1888; 136 years ago (1888)
Operator(s)San Francisco Public Utilities Commission
Dam and spillways
ImpoundsSan Mateo Creek
Height140 ft (43 m)
Length600 ft (180 m)
Width (base)40 ft (12 m)
Reservoir
CreatesLower Crystal Springs Reservoir
Total capacity57,910 acre⋅ft (71,430,000 m3)
Catchment area29.4 sq mi (76 km2)
Surface area1,323 acres (5.35 km2)

Crystal Springs Dam is a gravity dam constructed across the San Mateo Creek which is in San Mateo County, California. It impounds water to form the Lower Crystal Springs Reservoir which sits atop the San Andreas Fault in a rift valley created by the fault. The dam itself is located about 300 yards (273 meters) east of the fault.[1][2] It was among the first concrete gravity dams built in the western United States.[3] Skyline Boulevard runs over the dam, which also forms the trailhead of the popular Sawyer Camp Trail.

  1. ^ San Andreas Bay Area Faults
  2. ^ San Mateo Ezrim
  3. ^ Advanced Dam Engineering for Design, Construction, and Rehabilitation, by Robert B. Jansen, page 117