Refilling Diamond Valley Lake, Southern California’s Largest Reservoir

After three years of relying on stored reserves to meet Southern California water needs, the Metropolitan Water District of Southern California agency will refill the region’s largest reservoir, Diamond Valley Lake, with state supplies made available by this winter’s storms.

By News Desk

On Monday, March 27, Metropolitan and state officials shared the various operational actions being taken to maximize the amount of water stored in reservoirs and groundwater basins depleted by drought, to develop new local supplies, and to encourage efficient use of water across Southern California.

As the water cascaded from the top tier of DVL’s inlet/outlet tower into the lake, which is now at about 60 percent of capacity, officials watched as water formed a “bathtub ring” highlighting lowered levels of the lake.

During dry years, Metropolitan relies heavily on its reserves in Diamond Valley Lake to provide water to Southern California. Without this 810,000-acre-foot reservoir, near Hemet, the impact of the drought on the region would have been far worse. Built in the late 1990s, DVL is owned and operated by Metropolitan Water District. In addition to being a vital source of drinking water, DVL offers fishing and boating and a wildflower trail. Adjacent to the lake is the Southwestern Riverside County Multi-Species Reserve, a 13,500-acre protected preserve that is home to many sensitive, endangered or threatened native California bird, animal and plant species.