The Elsinore Valley Municipal Water District (EVMWD) provides water service to a 96 square mile area in western Riverside County. The District currently delivers a combination of local groundwater, local surface water and imported water purchased from the Metropolitan Water District of Southern California to meet the water demands of its customers. Due to its significant reliance on imported water supplies, EVMWD is susceptible to water shortages during a prolonged drought. To reduce this risk, EVMWD is considering the development of a groundwater storage program. Such a program would allow EVMWD to bank water during wet periods and extract this water during droughts or other periods of imported water reductions. The State of California has implemented a grant-funding program to encourage development of groundwater storage projects. The purpose of this program is to develop groundwater basins capable of storing sufficient water to offset all or a portion of water demand in times of drought or reduced of imported water availability. In spring of 2001, EVMWD applied to the California Department of Water Resources (DWR) for grants under the AB 303 and Proposition 13 Programs. The DWR awarded the EVMWD a grant in the amount of $250,000 under AB 303 for preparation of a Groundwater Management plan, and a grant in the amount of $1,493,250 under Proposition 13 for implementation of the Back Basin Injection Pilot Project. The primary objective of the groundwater management plan is to enhance the yield and improve the water supply reliability of the Elsinore Basin The goals for the groundwater management plan are:
• To develop a thorough understanding of the basin’s hydrogeologic characteristics.
• To enhance the yield and reliability of the groundwater supply. The basin is a major source of water supply for the EVMWD. However, EVMWD is also dependent on imported water for a portion of its water supply. As growth occurs, dependence on imported water will increase. During droughts, the District could be subject to cutbacks in imported water deliveries. Therefore, enhanced basin reliability through conjunctive use will be vital.
• To protect and enhance the water quality of the basin.
• To provide an equitable basis for financing basin management activities. Although the District is the principal groundwater producer in the Elsinore Basin, other groundwater producers would benefit from the development of a management plan.