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Calero Dam and Reservoir

The Santa Clara Valley Water District built the Calero Dam during the Great Depression, completing it in 1935 after acquiring land as the Santa Clara Valley Water Conservation District. The dam and reservoir is one of the six original reservoirs approved for construction by voters in May 1934.

Both dam and reservoir are located on Calero Creek. The 2.2-miles-long reservoir can store 9,934 acre-feet of water. Its surface area is 349 acres.* Calero Reservoir provides water directly to drinking water treatment plants, which treat and test it for safety. The district then distributes the water to water retailers to sell to the county’s 1.8 million residents. Calero also captures and stores winter runoff to recharge groundwater basins, helps store water from the nearby Almaden Reservoir watershed and accepts imported water.

The water district is currently in the midst of a seismic retrofit of the Calero Dam. To learn more about that project, click here.

*Reservoir storage values have been updated to reflect recent survey results.

Inundation Maps

Inundation Map of Hypothetical Fair Weather Failure of Calero Dam (2019) (index map)

Inundation Map of Hypothetical Fair Weather Failure of Calero Auxiliary Dam (2019) (index map)

Inundation Map of Hypothetical Inflow Design Flood Failure of Calero Dam and Calero Auxiliary Dam (2019)

Calero dam and reservoir