Diamond Valley Lake is a man-made off-stream reservoir located near Hemet, California, United States. It is one of the largest reservoirs in Southern California and also one of the newest. With a capacity of, the lake nearly doubled the area’s surface water storage capacity and provides additional water supplies for drought, peak summer, and emergency needs.The Metropolitan Water District of Southern California (MWD) began the $1.9 billion construction project in 1995. Filling of the lake, by way of the Colorado River Aqueduct, began in 1999 and was completed in 2003. The lake is currently served by the Inland Feeder.The lake features three earth fill dams, two located on either side of the valley and one on the north rim. Construction of the dams utilized nearby materials, and was one of the largest earthworks projects in the United States. Excavation of core materials for the dams resulted in many paleontological finds, all of which are displayed at the Western Science Center at the lake's East end. The lake is open to boating and fishing, along with hiking and other recreational activities around the lake.GeographyDiamond Valley Lake is located within the Domenigoni/Diamond valleys, between the Domenigoni Mountains and Rawson Mountains, southwest of the city of Hemet. The site was chosen because of its location between the cities of San Diego and Los Angeles, and because of the raw materials located on-site for the construction of the three dams. The location was also chosen because of its proximity, about, to the existing Colorado River Aqueduct that supplies the lake with water.
