Groundwater and local surface water is the county’s original source of water supply. Local rainfall and runoff flows into reservoirs for storage and blending with imported water. The water is released into creeks and ponds to augment natural percolation and maintain groundwater levels. Some of the local surface water is processed at drinking water treatment plants. The treated water is sold to local water retailers such as San Jose Water Company, who use their own distribution systems to serve customers. Water pumped from the groundwater aquifer through wells is used by private well owners, farmers, and water retailers.
About 55 percent of Santa Clara County’s water supply comes from hundreds of miles away - first as snow or rain in the Sierra Nevada range of northern and eastern California, then as water in rivers that flow into Sacramento-San Joaquin River Delta or directly to water conveyance systems. Often called “imported water”, it is brought into the county through the complex infrastructure of the State Water Project, the federal Central Valley Project and San Francisco’s Hetch Hetchy system.
A small, but important and growing source of water is recycled water. Used primarily for irrigation, industry and agriculture, recycled water is wastewater that has been purified to meet strict standards set by the California Department of Health Services. Using recycled water helps conserve drinking water supplies, provides a dependable, drought-proof, locally-controlled water supply, reduces dependency on imported water and groundwater and helps preserve our saltwater and tidal habitat by reducing freshwater discharge to the bay.
Did you know that only less than 1 percent of all water on Earth is suitable for use by people? The rest is salt water, like the kind found in the ocean, or is permanently frozen. We can’t drink it, wash with it or use it to water plants. With California in the midst of drought, we must be careful not to waste this precious limited resource.