Construction is underway at Castaic Lake, as officials from the California Department of Water Resources work to make seismic improvements on Castaic Dam’s tower access bridge.

Castaic Lake is one of many State Water Project facilities that supply water to the state, specifically providing water for the greater Los Angeles area and more than 5.2 million Californians in 2019, according to DWR.

DWR is modernizing its SWP facilities as it works to identify and proactively address any issues that could impact water supplies across the state.

“We’re moving forward on some of these projects to increase the resiliency of the facilities, and this was one of the projects that we’re doing to increase the seismic capacity of this bridge so that it doesn’t fail in a very large earthquake,” added Jason Brabec, DWR supervising engineer for the Castaic Dam Modernization Program.

As part of the Castaic project, the tower access bridge’s piers are being strengthened with a reinforced fiber wrap, among other improvements being completed on the superstructure, Brabec said.

Scaffolding surrounds a partially completed column during this portion of a Castaic Dam Modernization Project whose goal is to allow the facility to better withstand earthquakes’ effects by among other things, wrapping piers with sections of Fiber Reinforced Polymer for the first time. The column in white is a completely wrapped section on Oct. 4, 2021. Courtesy of Andrew Innerarity/DWR

However, before work could begin on the bridge, DWR worked to lower the water level of Castaic Lake to access the submerged bridge piers.

“This has been a project we’ve been working on with our stakeholders for at least two and a half years, because drawing down the lake is a big endeavor,” Brabec said, adding that the temporary drawdown began in May.

Department of Water Resources Engineer Angela Hall , left, and DWR Project Manager Jason Brabec, right, walk along the tower access bridge during this portion of a Castaic Dam Modernization Project designed to allow the facility to better withstand earthquakes’ effects by among other things, wrapping piers of the dam’s tower access bridge with sections of Fiber Reinforced Polymer for the first time on Oct. 4, 2021. Courtesy of Andrew Innerarity/DWR

DWR has also worked in conjunction with the L.A. County Department of Parks and Recreation to minimize the impact on the community, notifying boaters and other lake users of the lower lake levels.

Through the drawdown, the upper lake remains fully accessible to the public, and water deliveries have continued to the state water contractors, while the lower lagoon’s water levels have not been impacted, according to Brabec.

DWR is also continuing to do further investigations to see what additional infrastructure rehabilitation work is needed, if any, so the facility continues to meet DWR standards for continued operation, Brabec added.

A drone view of Castaic Lake and the dam taken Feb. 17, 2021. Courtesy of Kelly M Grow/DWR

A drone view of Castaic Lagoon and the bottom of Castaic Dam emergency spillway on Feb. 17, 2021. Courtesy of Kelly M Grow/DWR

DWR is set to operate construction equipment in all phases of the modernization program, with some localized noise and increased activity expected, particularly during rehabilitation construction efforts.

DWR’s project continues to be on schedule, both in the drawdown and the construction work, with the project expected to wrap up in early 2022.

For more information on the Castaic Dam Modernization Program, visit water.ca.gov/Programs/State-Water-Project/SWP-Facilities/Southern/Castaic-Dam-Modernization.