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 are located along Hicks Creek on Guadalupe Creek, a tributary of the Guadalupe River.
Issues facing the dam and reservoir
Guadalupe Reservoir, which can store about 3,415 acre-feet of water, has a critical problem of extensive mercury contamination. It lies about two miles from the now closed New Almaden Mines, once one of the largest mercury producing mines in the Americas, and still feels the effects of the old work, particularly during large runoff events when mercury containing sediments from mine wastes get into the water from the mining areas. The reservoir is impaired because of its level of toxicity. For more information on how the water district has addressed the problem, click here.
The Guadalupe Dam, meanhwile, will soon be the subject of a seismic upgrade to shore up the dam after a 2011 engineering study found it to be a risk during a large earthquake.
Guadalupe Dam Inundation Maps_2014
*Reservoir storage values have been updated to reflect recent survey results.