The Desert Water Agency and the Coachella Valley Water District, both in Riverside County, have entitlements to State Water Project (SWP) water, but they lack any physical connection to its facilities. However, both agencies are adjacent to the Colorado River Aqueduct (CRA). In order to enable these agencies to obtain water equal to their SWP entitlement, Metropolitan Water District (MWD) has agreed to exchange an equal quantity of its Colorado River water for the Desert Water Agency and Coachella Valley Water District's SWP water.
These exchanges provide water to MWD with a lower concentration of total dissolved solids than it would otherwise receive, and they allow the Desert Water Agency and Coachella Valley Water District to obtain imported water supplies that they could not otherwise access. The original exchange contracts were to be in effect from 1967 through January 1990, but in 1983 they were extended through 2035.
The maximum amount that can be stored under this agreement is 600,000 acre-feet (af), and the maximum annual withdrawal is currently 61,200 af.
In 1984, MWD executed an advance delivery agreement with these agencies. This agreement allows MWD to supply the Desert Water Agency and Coachella Valley Water District with Colorado River water in advance of the time they are entitled to receive water under the exchange contracts. In future years, MWD can recover this water by reducing its deliveries under the exchange contracts.
MWD is currently investigating transferring a portion of its SWP water to the Desert Water Agency and Coachella Valley Water District. This proposal is currently undergoing an environmental impact review.
MWD is also exploring an additional program with these agencies. Under the current Advance Delivery Program, MWD delivers water near the Whitewater Recharge area. This provides water to the upper Coachella Valley groundwater basin underlying the Desert Water Agency service area. The upper basin is nearing capacity and the lower basin is overdrafted. The technical relationship between the upper and lower basins has yet to be determined. MWD's board has authorized the expenditure of $750,000 for a feasibility study of the conjunctive use program that would store water in the lower basin. This may require the construction of new facilities. Current expectations are that this new program could provide MWD with the right to withdraw 100,000 to 150,000 af per year, over a ten-year cycle.