The San Vicente Dam Raise Project has secured the 5th International Commission on Large Dams (ICOLD) International Milestone Award for Roller Compacted Concrete Dam, the San Diego County Water Authority has announced.
Employing RCC streamlined the construction process of the project, resulting in significant time and cost savings while fortifying the structure to withstand a 7.5 magnitude earthquake.
Completed in 2014, the ambitious dam raise initiative elevated the San Vicente Dam by 117ft (35.7m), equivalent to adding a towering 12-story building atop the original structure. The expansion more than doubled the San Vicente Reservoir's capacity, contributing an additional 152,000-acre feet of water storage – ample to sustain over 450,000 households for an entire year. The dam now stands 337ft (102.7m) tall.
Water Authority Board Chair, Mel Katz, expressed pride in the recognition, stating: “This award is a reminder that the San Diego region has a long history of strategic investments to protect our most important natural resource. The San Vicente Dam Raise was a landmark project and one that inspires us as we seek solutions to current and future challenges.”
Owned and operated by the City of San Diego since its construction in 1943, the expanded reservoir's capacity is shared between the city and the Water Authority. Both entities also jointly bear the operational costs of the reservoir.
“Raising the San Vicente Dam was a massive feat of engineering and it’s recognized as the world’s tallest dam extension using roller compacted concrete,” said Water Authority Engineering Director Neena Kuzmich. “More importantly, it was the final major element of the Water Authority’s $1.5 billion Emergency Storage Project, a system of reservoirs, pipelines and pumping stations designed to secure a six-month supply of drinking water for the San Diego region in case a natural disaster such as an earthquake or a prolonged drought interrupts imported water deliveries.”
Commencing in 2009, preparations for the dam expansion involved utilizing RCC as a fundamental design element. Unlike traditional wet concrete, RCC employs reduced amounts of cement and water to create a cookie dough or clay-like texture. The layer-by-layer placement and compaction process, reminiscent of road construction, expedited the construction timeline while meeting all technical requirements.
During the final phase, Stantec designed the 117ft (35.7m) raise of the existing 219ft (67m) high San Vicente Dam. The utilization of on-site quarries for RCC aggregates promoted environmental stewardship and eliminated over 100,000 truck deliveries from off-site sources.
Image of the project courtesy of Stantec
