The San Diego County Water Authority has completed a raise of the San Vicente Dam, adding 152,000 acre-feet of water storage capacity to the reservoir.
The dam raise represents the largest and final element of the authority’s US$1.5 billion Emergency Storage Project, which is a system of reservoirs, interconnected pipelines and pumping stations designed to ensure a six-month supply of water for the San Diego region.
SDCWA said about a third of the increased reservoir’s capacity is for emergency use, while the remainder will serve as “carryover storage” designed to be filled in wet years and tapped in dry years.
“This vital enhancement to the region’s water storage system will protect our economy and quality of life during future droughts and water supply emergencies,” SDCWA chairman Thomas V. Wornham said. “It proves once again that our region’s water agencies, civic leaders and ratepayers are committed to doing what it takes to maintain a reliable supply of water, not only for today but for generations to come.”
The $416 million San Vicente project represents the largest raise of a concrete dam in the United States and the largest raise using roller-compacted concrete in the world. In all, the project increased the dam’s height by 117 feet and used more than 600,000 cubic yards concrete and 150 tons of steel.
“This project improves water security for everyone living in the San Diego region as well as thousands of businesses that depend on a reliable water source to thrive,” San Diego mayor Kevin L. Faulconer said. “This project provides a template for how we can complete bold and visionary projects by working together.”
Construction started in 2000 on the comprehensive set of water storage and delivery enhancements that are part of the authority’s Emergency Storage Project. The project included building Olivenhain Dam in North County along with a pipeline connecting Olivenhain Reservoir to the Water Authority’s Second Aqueduct, an 11-mile pipeline connecting San Vicente Reservoir to the SDCWA Second Aqueduct, and pumping facilities at Lake Hodges and San Vicente Reservoir. The expanded pipeline system allows for regional distribution of water during emergencies. HydroWorld.com reported that the water authority had voted in favor of the dam raise in April 2008.
Expanding San Vicente Reservoir started as a part of the Emergency Storage Project. After Water Authority studies showed the need for more carryover storage in the region, the dam raise was “super-sized” to also include dry-year storage in the reservoir.
“By combining two projects into one, we were able to make a huge addition to our water reserves more quickly and continue our legacy of optimizing our assets for regional benefit,” said Maureen Stapleton, general manager of the Water Authority. “Super-sizing the dam raise proved to be the best way to realize the water supply benefits the region needed at the best value for ratepayers.”
San Diego County Water Authority is currently exploring the possibility of adding a 500 MW pumped-storage plant near San Vicente Dam following the closure of the 2,200-MW San Onofre nuclear power plant.