As part of the Castaic Dam Modernization work in Los Angeles County, DWR geologists perform rock core drilling along the dam's east side to verify the geology for the installation of groundwater monitoring equipment. Photo Credit: Chris Silva, DWR Division of Engineering
SACRAMENTO, Calif. – Two key projects are set to begin as part of ongoing modernization work at Castaic Dam in Los Angeles County to reduce risks from a major earthquake. The California Department of Water Resources (DWR) will oversee the installation of new equipment to monitor the dam’s stability and work to strengthen the dam’s intake tower access bridge.
“These projects are important to helping us ensure Castaic Dam continues to operate safely and provides reliable and affordable water supply,” said DWR Deputy Director Ted Craddock, who oversees the State Water Project. “In addition to providing water supply for Southern California, Castaic Lake offers many recreational opportunities for surrounding communities.”
Monitoring equipment known as piezometers will be installed in wells adjacent to the dam’s east side. The piezometers will measure groundwater trends over time to monitor the dam’s stability. DWR will install a total of nine new piezometers and decommission three aging piezometers to improve data collection capabilities for reliable and accurate data.
During the piezometer installation, construction equipment, such as drill rigs and heavy machinery, will be used to perform the work. Increased noise and activity at the site are expected during the project, which should be completed by the end of June 2021.
As the piezometer work wraps up, Castaic Dam’s intake tower access bridge work will begin. It is expected to continue until spring 2022. Bridge work includes strengthening the tower bridge piers, which requires the temporary drawdown of Castaic Lake to access the piers.
During the drawdown that will begin in early May, all visitors are advised to stay safe during fluctuating water levels by being aware and staying away from hazards in the water. The reservoir will reach a low elevation of 1,380 feet above mean sea level by fall 2021. The water level will be lowered by over 100 feet during this period. By spring 2022, Castaic Lake will return to normal operations with water levels based on available conditions at that time.
DWR kicked off the Castaic Modernization Program in 2018. The program includes reducing seismic risk to the intake tower and access bridge, evaluation of the spillway to identify and implement necessary modifications, and earthquake monitoring capabilities on various dam components.
For more information about the Castaic Dam Modernization Program, visit the DWR website.
Castaic Lake, completed in 1974 and located 45 miles north of downtown Los Angeles, provides a water supply to more than 5.2 million Californians. The lake offers a variety of recreational opportunities and provides regulatory storage for power generation. For updates about recreational opportunities at Castaic Lake, visit website.
Contact:
Maggie Macias, Public Affairs, Department of Water Resources
(916) 653-8743 | maggie.macias@water.ca.gov