As another storm approaches the region, the San Diego County Water Authority and its member agencies for the first time have taken advantage of wet winter conditions to pump captured local runoff out of Lake Hodges and store it elsewhere for future use.
The Water Authority, at the request of the City of San Diego, has moved approximately 7,500 acre-feet of water (enough to meet the annual needs of 15,000 single-family households) from Lake Hodges to the Olivenhain Reservoir. The Water Authority is now transferring that water to bolster the city’s supplies in the city-owned San Vicente Reservoir near Lakeside.
Lake Hodges, which had been filled to within four feet of capacity several weeks ago because of previous storms, now has more than 8,000 acre-feet of room to capture additional runoff from this week’s rainfall and from future storm events this spring. (Lake Hodges is owned by the City of San Diego, and both the city and the Water Authority have storage rights in the reservoir.)
“The transfer is another example of the region’s enhanced water management capabilities created by our internationally acclaimed Emergency & Carryover Storage Project,” said Mark Muir, chair of the Water Authority’s Board of Directors. “Last year, the E&CSP allowed us to store more than 100,000 acre-feet of conserved water in the newly expanded San Vicente Reservoir for future use. This year marks the first time since we completed our Lake Hodges Pumped Storage facilities that Mother Nature has given us enough rainfall to allow us to move a significant amount of captured runoff from Lake Hodges to further increase our region’s water reserves. These facilities will continue to boost water supply reliability for our region’s 3.3 million people and $222 billion economy for decades.”
All of the major infrastructure involved in this transfer were built or expanded as part of the E&CSP:
- The Olivenhain Dam and Reservoir, Pipeline and Pump Station, which were completed in 2003,included construction of a 318-foot-tall dam that added 24,000 acre-feet of water storage, including 18,000 acre-feet of emergency storage.
- The Lake Hodges Pipeline and Pump Station, which connected Olivenhain Reservoir to Lake Hodges, provided access to up to 20,000 acre-feet of emergency water storage in Lake Hodges and enabled the transfer of available local runoff stored in the reservoir. The pipeline was completed in 2007; the pump station was completed and operational in 2012. Prior to the completion of this project, Lake Hodges water was only available for customers of the San Dieguito Water District and the Santa Fe Irrigation District.
- The San Vicente Pipeline and Pump Station includes an11-mile, 12-foot-diameter tunnel and 8.5-foot-diameter pipeline connecting the San Vicente Reservoir to the Water Authority’s Second Aqueduct, and the pump station moves the water from the reservoir to the aqueduct. The pump station was completed in 2010 and the pipeline was completed in 2011.
- The San Vicente Dam Raise,the tallest dam raise in the nation, raised the dam by 117 feet, creating 52,100 acre-feet of emergency water storage capacity and 100,000 acre-feet of carryover storage capacity – water stored during wet years to help meet demands in dry years – for the Water Authority. Major construction was completed in 2014. (The City of San Diego owns and operates the reservoir and retains the original reservoir’s 90,000 acre-feet of storage capacity.)
The E&CSP, which has comprised $1.5 billion in investments since 1992, is designed to ensure up to six months of local supplies are available and can be moved around the region after an emergency, such as an earthquake that damages the large-scale pipelines delivering imported water into the region. It also added 100,000 acre-feet of local carryover storage. Overall, it added 196,000 acre-feet of locally available water storage.
Last week, the American Society of Civil Engineers awarded the E&CSP its 2017 Outstanding Civil Engineering Achievement Award, one of the engineering industry’s most prestigious global awards, noting how the project anticipated the need to help the region solve future water supply challenges. More information on the ASCE award is at http://news.asce.org/emergency-and-carryover-storage-project-earns-ocea/.
More information on the E&CSP is at http://www.sdcwa.org/emergency-carryover-storage-project.