Your Water
Ensuring safe, reliable water
Your Water
Page Title
Your Water
Back to top

Groundwater Studies


Zone of Benefit  

Valley Water protects and replenishes local groundwater supplies to ensure water supply reliability for Santa Clara County. Management of the sustainable groundwater supply is funded by groundwater charges, which are applied to groundwater pumpers within zones benefiting from district activities. These activities include replenishing groundwater with local and imported surface water, monitoring and protecting groundwater from pollutants, and constructing, operating, and maintaining facilities that help sustain groundwater supplies.

The district is currently conducting a study to evaluate the extent of the zones of benefit to ensure they accurately reflect the areas receiving benefit from district activities to protect and replenish groundwater. The study is not evaluating the rates that are charged within the zone of benefit. This study will provide the district with a scientific, transparent basis for proposing changes to the current zones of benefit, if necessary.

Salt and Nutrient Management Plans

Valley Water lead the effort to prepare Salt and Nutrient Management Plans (SNMP) for the Santa Clara and Llagas Groundwater Subbasins in Santa Clara County. This stakeholder-driven process assessed all salt and nutrient loading in the subbasins to evaluate existing and projected future assimilative capacity, as required by the State Water Resources Control Board 2009 Recycled Water Policy.

Recycled Water Irrigation and Groundwater Study (August 2011)

Valley Water initiated this multi-year study in 2007 to advance water district policies of aggressively protecting groundwater and supporting recycled water development in Santa Clara County.

The goal of this study was to evaluate the potential effects of recycled water used for irrigation on groundwater quality and to identify best management practices to protect groundwater quality.

The study included laboratory testing of soils irrigated with recycled water and an 18-month field study at a site using recycled water for irrigation.

Groundwater Vulnerability Study (October 2010)

The goal of this study was to predict the vulnerability of groundwater to potentially contaminating land use activities to allow Valley Water to prioritize groundwater protection efforts and resources on the most vulnerable areas, evaluate groundwater quality impacts from land use changes, and provide information to decision makers at the district, land use agencies, and regulatory agencies to improve groundwater protection.

Related Files
Attachment Size
Groundwater Vulnerability Study 10.5 MB

Solvent Studies

Valley Water has conducted several studies related to solvents and the related threat to groundwater resources. This includes a study on the threat posed by current and former dry cleaning sites in Santa Clara County and a white paper on solvent stabilizers, including 1,4-dioxane.