MWA is responsibly using State Water Project resources
Nearly all the water supplied to businesses, homes, and farms throughout the High Desert is pumped from groundwater. Production wells exist throughout the region, owned by a multitude of water users from homeowners with domestic wells to large water districts, with some wells pumping millions of gallons every day.
The Mojave River is the primary source of "recharge" to groundwater. On average, about 54,000 acre-feet of water enters groundwater basins within the Mojave Water Agency (an acre-foot is roughly the amount of water two households use in a year). Most of the natural water flows entering local aquifers originate in the San Bernardino Mountains and reach the Mojave River in the form of runoff from rainfall or snowmelt.
The State Water Project
Although the area receives substantial natural inflows of water, the High Desert region has been in overdraft for decades—that is, more water is pumped from groundwater basins than what goes in. To make up the difference, MWA is using State Water Project resources, delivering water from the State Water Project (SWP) to groundwater recharge sites throughout the region to supplement natural water supplies. MWA’s currently has access to an average of 50,000 acre-feet per year in water supplies from the SWP. Click here to view a map of MWA’s SWP delivery facilities.
A Watershed Approach - the Adjudication
As a result of a lawsuit in the early 1990’s, a court Judgment adjudicated water rights in the Mojave Basin Area. MWA serves as the court-appointed Watermaster over the Mojave Basin Area, implementing the Judgment. During the Adjudication, water rights were divided up according to the producers’ historical water use, and then "ramped-down" proportionately among water users to a level roughly equal to the natural yield of the basins. To the extent that water users pump more than their "right," they pay MWA to import supplemental water supply from the SWP to make up for the over-pumping. The Watermaster takes a holistic approach to accounting for water entering and leaving the basins, keeping records of groundwater pumping, natural and imported water flows into the basins, and other sources of groundwater recharge such as treated wastewater. The goal is to provide a sustainable water supply, keeping groundwater basins in balance over the long-term.