Historic San Vicente Dam Raise Project Completed
July 16, 2014
The largest water storage project in San Diego County history is complete, providing the region with a critical hedge against…
The largest water storage project in San Diego County history is complete, providing the region with a critical hedge against future water shortages.
The San Vicente Dam Raise project adds 152,000 acre-feet of water storage capacity to the reservoir, enough to serve more than 300,000 homes for a year. Filling the reservoir will take two to five years, depending on water supply and demand conditions statewide. The newly added storage volume is greater than any reservoir in the county.
The San Vicente Dam Raise Project is the largest piece and final major element of the Water Authority’s $1.5 billion Emergency Storage Project, a system of reservoirs, interconnected pipelines, and pumping stations designed to ensure a six-month supply of water for the San Diego region in case imported water deliveries are interrupted – for instance, by an earthquake. About one-third of the reservoir’s new capacity – 52,000 acre-feet – is for emergency use. The project also provides 100,000 acre-feet of “carryover” storage that is designed to be filled during wet years and tapped in dry years.
The dam raise project cost $416 million. Related projects that include a surge tank, a pump station and 11 miles of large-diameter underground pipeline brought the overall cost to $838 million.
Approximately 200 state and local water leaders, elected officials, civic and business leaders, and community stakeholders attended a dam raise dedication celebration at the project site on Wednesday.
“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,” said Thomas V. Wornham, Chair of the Water Authority’s Board of Directors. “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.”
San Vicente Dam has been owned and operated by the city of San Diego since it was built in 1943 to hold 90,000 acre-feet of water for city customers. Capacity in the enlarged reservoir is shared by the city (90,000 acre-feet) and the Water Authority (152,000 acre-feet). The Water Authority and the city will share the cost of operating the expanded reservoir.
“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,” said San Diego Mayor Kevin L. Faulconer. “I’m proud the city helped make this happen with our great partners at the San Diego County Water Authority. This project provides a template for how we can complete bold and visionary projects by working together.”
John Laird, secretary of the California Natural Resources Agency, also attended Wednesday’s ceremony. “Ongoing statewide drought conditions highlight the need for forward-thinking projects like the San Vicente Dam Raise,” Laird said. “The Water Authority should be congratulated for starting this project well before the current drought hit, and all Californians should see this as an example of what’s possible with good planning and strong financial commitment to water supply reliability.”
San Diego Regional Chamber of Commerce President and CEO Jerry Sanders praised the Water Authority’s efforts to diversify its water supplies so that the region is no longer dependent on a single supplier for almost all of its water. “This has been a top public policy priority at the Chamber for years,” Sanders said. “By combining a diversified set of water supply sources with greatly enhanced storage capacity, we are developing a more robust safety net for San Diego County.”
“A reliable water supply is critical for economic growth and maintaining a competitive business climate,” said Mark Cafferty, president and CEO of the San Diego Regional Economic Development Corp. “The raised dam will enhance San Diego County’s position as a prime spot for starting or growing a company because it provides greater assurance that we can weather future droughts and emergencies.”
Construction started in 2000 on the comprehensive set of water storage and delivery enhancements that are part of the Water 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 Water Authority’s Second Aqueduct, and pumping facilities at Lake Hodges and San Vicente Reservoir. The expanded pipeline system allows for regional distribution of water during emergencies.
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.”
Preparatory work on the foundation for the enlarged San Vicente Dam began in June 2009, and construction concluded in June 2014. The dam now stands 337 feet tall, an increase of 117 feet. It was the tallest dam raise in the nation and the tallest in the world using a construction technique called roller-compacted concrete. Roller-compacted concrete is just as strong as conventional concrete but takes less time and water. It is placed in layers, one on top of the other, in a process that resembles road construction.
Concrete for the San Vicente project was custom-designed to match the strength of the original dam, allowing the two sections of concrete to function as one unit. Almost all of the concrete was produced on site with material mined from the hillsides near the old marina, avoiding 100,000 delivery truck trips through the local community.
The Water Authority also conducted a comprehensive environmental mitigation program for the project. The program met all wildlife agency permit requirements and created, enhanced, restored or preserved more than 670 acres of sensitive upland and wetland habitats from Oceanside to Imperial Beach. In many locations, the mitigation program resulted in multiple public benefits, such as watershed protection and preserving existing trail systems.
Now that work is finished on the dam, remaining construction projects in the area include the completion of a new, improved marina that will feature twice as many boat launch lanes, a longer boat ramp and more parking spaces. In addition, a new pipeline will be built for the city of San Diego to replace a section that will be under water when the expanded reservoir is full. The ancillary projects are expected to be completed in 2015.
The city of San Diego plans to reopen the reservoir to the public as soon as the water level reaches the new boat ramp, which will depend on the availability of imported water and local rainfall along with local water demand.