A 2012 independent engineering study of the Guadalupe Dam found that during a large earthquake, the dam could deform significantly, resulting in an uncontrollable release of reservoir water. In response, the state Division of Safety and Dams (DSOD) imposed storage restrictions for the reservoir of 18-feet below the dam spillway crest, keeping water levels lower than normal to prevent over spilling until the water district assesses and conducts corrective action to restore the dam’s full integrity.
The Santa Clara Valley Water District is moving forward on the project design for the Guadalupe Dam Seismic Repair Project. On March 8, 2018, the district held a scoping meeting on the project, collecting public input that will help form the final Environmental Impact Report. This report, known as an EIR, identifies likely effects of the project on the surrounding area and proposes measures to offset them.
The district will continue to accept written comments until April 9, 2018. In the fall, the public will have the opportunity to review the draft EIR and attend a water district board meeting when directors prepare to certify the report.
Stabilizes dam embankments
Modifies or replaces outlet works
Modifies or replaces the spillway to increase freeboard
The Santa Clara Valley Water District built the Guadalupe 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.
The reservoir’s surface area is 74 acres. Both the dam and reservoir are located along Hicks Creek on Guadalupe Creek, a tributary of the Guadalupe River.
The reservoir primarily stores water for recharging groundwater basins. Groundwater is present beneath the surface in soil pore spaces and in fractures of rock formations and supplies and provides nearly half the drinking water each year for Santa Clara County’s residents.