Flexibility and Minimal Visual Impact Key to Supporting Power Lines at Olivenhain Dam

摘要

The San Diego area has been dependent on distant water resources for more than a century. The San Diego County Water Authority (SDCWA) imports water from the California State Water Project, a 500-mile long connection to water sources in northern California, and from the Colorado River via a 200-mile long aqueduct system. Since these systems cross several fault lines, they have always been at risk because of California's susceptibility to earthquakes. Consequently in 1998, an $827 million project was approved in order to construct the Olivenhain Dam reservoir and related water system improvements. The Olivenhain Dam is the center- piece of the project. The goal of the project co-owners, SDCWA and Olivenhain Municipal Water District, was to build a reservoir with sufficient water storage capacity (24,000 acre-ft.) to supply the San Diego area in case of prolonged interruption of its imported water supply caused by either earthquakes or other natural or man-made events. The dam itself was designed to remain fully operational following an earthquake up to a Richter magnitude of 7.25. Located in a mountainous forest preserve area north of San Diego, the dam measures 318-ft. high by 2,586-ft. long, which made it the largest dam constructed of roller-compacted concrete (RCC) in the United States as well as California's first RCC gravity dam.