Groundwater

Groundwater exists beneath the earth’s surface within the soil and rock pore spaces, fractures, and caverns. As part of the hydrologic cycle, groundwater generally flows with the topography, from high to low areas, and ultimately discharges into rivers, lakes, or the ocean. In this way, groundwater and surface water are essentially one resource. Groundwater and surface water interactions are controlled by their hydraulic communication. Groundwater basins are thick accumulations of soils and sediments that often occur in valleys or other areas between bedrock slopes or ridges. Aquifers are the more permeable soil and rock formations where groundwater yields are higher than surrounding areas. Groundwater for human use is most often tapped by wells installed within an aquifer, or by naturally-occurring springs.

Groundwater basins are thick accumulations of soils and sediments that often occur in valleys or other areas between bedrock slopes or ridges. Aquifers are the more permeable soil and rock formations where groundwater yields are higher than surrounding areas. Groundwater for human use is most often tapped by wells installed within an aquifer, or by naturally-occurring springs. For more information visit the following links:

• California Department of Water Resource’s Groundwater Information
• USGS Hydrologic Cycle Information
• USGS Interconnected Surface Water Depletion
• USGS Aquifer and Groundwater Information

Existing and potential beneficial uses applicable to groundwater in the Region include municipal and domestic water supply (MUN), industrial water supply (IND), industrial process supply (PRO), agricultural supply (AGR), groundwater recharge (GWR), and freshwater replenishment to surface waters (FRSH). Groundwater also replenishes and moderates the temperatures of streams, rivers, and wetlands supporting wildlife including threatened and endangered species. Unless otherwise designated by the Water Board, all groundwater is considered suitable, or potentially suitable, for municipal or domestic water supply (MUN). In making any exceptions, the Water Board will consider the criteria referenced in State Water Board Resolution No. 88-63 and Water Board Resolution No. 89-39, “Sources of Drinking Water”.