Work has begun on the San Diego County Water Authority’s $450 million project to raise the height of the San Vicente Dam from 220 feet to 337 feet. Raising the dam by 117 feet will require about 650,000 cubic yards of roller-compacted concrete, which is enough to fill a football field more than 28 stories high. According to the CWA, the concrete will travel about a half mile on a conveyor belt from the concrete batch plant in the reservoir’s former marina area to the main dam. It will then drop through a chute, almost 200 feet high, where it will be roller-compacted into place. When completed in about two years, the raised dam will create room for an additional 52,100 acre-feet of water for potential emergency use, and an additional 100,000 acre-feet of capacity to store water during wet years, for use in subsequent dry years (an acre-foot is about 326,000 gallons, or enough to supply two average single-family households of four people for a year.)
The project is one of the last in the CWA’s program to improve the region’s emergency storage capacity in case water deliveries from the north are cut off. The larger reservoir will also help San Diegans get through drought years. The project includes an improved access road, expanded boat ramp and parking lot, and new shade trees and picnic areas. The CWA plans to refill the reservoir between late 2014 and 2017, depending on rainfall, supply and demand for water. The San Vicente Dam was completed in 1943, and the reservoir was connected to the CWA’s aqueduct four years later. “This vital regional water infrastructure project will help enhance the reliability of San Diego County’s water supply for generations to come,”’ said Michael Hogan, chairman of the CWA Board of Directors.
