Diamond Valley Lake - Construction

Construction

Planning for the lake began in early 1987. The main goal was to find a way to meet Southern California seasonal, drought and emergency needs. MWD chose the current site, because of its geographical location, and began construction planning in 1993. Construction of the lake in 1995 with construction of the three dams. With over 40 million cubic yards of foundation excavation and 110 million cubic yards of embankment construction, the construction of the dams was the largest earthworks project in the United States. The shovels, loaders and trucks used on the project were the largest available in the industry and established a new standard for earth and rock movement. The two rock processing plants set up for the project provided combined production exceeding the capability of any single commercial processing operation in California. Construction of the lake was the largest construction project by the MWD since building the Colorado River Aqueduct.

At its peak in 1997 and 1998, the reservoir construction project employed an average of 1,800 people. At times, more than 1,900 people labored in building the reservoir’s three dams. From start to finish, about 5,000 people were employed by the construction project.