| Crystal Springs Dam | |
|---|---|
| Official name | Lower Crystal Springs Dam |
| Location | San Mateo County, California |
| Opening date | 1888 |
| Dam and spillways | |
| Height | 140 ft (43 m) |
| Length | 600 ft (180 m) |
| Base width | 40 ft (12 m) |
| Impounds | San Mateo Creek |
| Reservoir | |
| Creates | Lower Crystal Springs Reservoir |
| Capacity | 57,910 acre·ft (71,430,000 m3) |
| Catchment area | 29.4 sq mi (76 km2) |
| Surface area | 1,323 acres (5.35 km2) |
Crystal Springs Dam is a gravity dam constructed across the San Mateo Creek, impounding water to form the Lower Crystal Springs Reservoir in San Mateo County, California.
The structure was completed in 1888, and has survived both the 1906 San Francisco earthquake and the 1989 Loma Prieta earthquake — despite its location directly on the San Andreas Fault.
The dam has a road running over it and forms the trailhead of the popular Sawyer Camp Trail.
Currently the dam is undergoing renovations. The dam is being raised to increase the water storage capacity of the reservoir as well as other changes. The roadway on top of the dam is closed.