Where Does My Tap Water Come From?

Scroll down to see Ventura County, Greater Los Angeles County, and the Upper Santa Clara River Watershed’s main sources of water for their region.

Ventura County Water Supply

• The water supply in Ventura County comes from three main sources: groundwater, the State Water Project, and other local surface water.
• 67% of the water sources is groundwater, which is pumped by individual well owners and by public and private water purveryors within Ventura County.
• The source of tap (or drinking) water in our community is a blend of imported State Water and local groundwater treated to meet state and federal drinking water quality standards.

*Percentages fluctuate based on climate conditions
Source: Project Changes in Ventura County Climate, Western Regional Climate Center, Desert Research Institute, 2019
*Percentages fluctuate based on climate conditions Source: Project Changes in Ventura County Climate, Western Regional Climate Center, Desert Research Institute, 2019

Greater Los Angeles County Water Supply

The water supply for the Greater Los Angeles County IRWM comes from three main sources: 1) imported water (including the State Water Project, Colorado River Aqueduct, and Los Angeles Aqueduct), 2) local surface water and recycled water, and 3) groundwater.

*Percentages fluctuate based on climate conditions
Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014
*Percentages fluctuate based on climate conditions Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014

Upper Santa Clara River Watershed Water Supply

The water supply for the USCR IRWM comes from three main sources:
(1) California State Water Project

(2) Water recycling

(3) Groundwater

The State Water Project is sourced from snow pack and rain from the Sierra Nevada range, flows to the Sacramento-San Joaquin Delta, then through the State Water Project Aqueduct to supply water to Los Angeles County. Water recycling allows for municipal wastewater to be treated and re-utilized. Groundwater is the water stored beneath the Earth’s surface. Wells are used to pump the groundwater into our water supply system.

Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014
Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014