State Water Project Modernization Highlights - 2019


Crews install piezometers on the gated spilway for the Pyramid Dam Modernization project in Los Angeles County, California.

Crews install piezometers on the gated spilway for the Pyramid Dam Modernization project in Los Angeles County. DWR/2019

The Department of Water Resources (DWR) is moving forward with the modernization of State Water Project (SWP) facilities across the state to reduce seismic and hydrologic risks. Several projects kicked off in 2019 across California.

Current and proposed projects represent a significant investment in addressing seismic and hydrologic risks to California’s water infrastructure. As we enter a new year, DWR will continue to identify and make improvements to SWP facilities that will ensure public safety and a reliable water supply.

  • Pyramid Dam Modernization Program in Los Angeles County kicked off in September 2019 with assessments on the condition of the facility and possible improvements to the emergency and gated spillways. The gated spillway is used approximately once per year and the emergency spillway has never been used. DWR wants to continue safe operations of the gated spillway and emergency spillway if used. Field investigations will be completed in early 2020 and evaluations are planned for completion in 2022.
  • Castaic Dam Modernization Program in Los Angeles County began on October 28, 2019 with the assessment of the integrity of a 60-foot-wide rectangular concrete chute used to pass natural flows from Castaic Lake into Castaic Lagoon. DWR will conduct additional assessments of the dam, spillway, intake towers, and other associated structures to ensure that the dam continues to operate safely and reliably. The modernization efforts of the dam facility are expected to take about 10 years.


  • At Perris Dam in Riverside County, DWR began retrofit work on October 2, 2019 on the outlet tower bridge, which is a part of the Perris Dam complex. The bridge work, which is the second of three Perris Dam seismic retrofit projects, includes modifications to the bridge support and seat. The tower bridge retrofit is expected to be completed by fall of 2020.

  • At Sisk Dam in Merced County, DWR and the U.S. Bureau of Reclamation completed final environmental impact statement/report and initiated geotechnical explorations for seismic retrofit of Sisk Dam in 2019.