NOI to Adopt a Mitigated Negative Declaration for the Castaic Dam High Intake Tower Bridge Retrofit Project


The California Department of Water Resources (DWR) has released a draft Initial Study (IS) and intends to adopt a Mitigated Negative Declaration (MND) for the proposed Castaic Dam High Intake Tower Bridge Retrofit Project (proposed project). The draft IS and proposed MND have been prepared in accordance with the California Environmental Quality Act to provide agencies, the public, and interested parties an opportunity to review the environmental analysis for the proposed project.

The proposed project is located at Castaic Lake, approximately 40 miles northwest of downtown Los Angeles within the Sierra Pelona Mountains, north of Santa Clarita along Interstate 5. The Castaic Dam high intake tower and bridge are located within the southwest portion of the lake on Castaic Dam’s right abutment.

DWR is proposing to implement the project to seismically retrofit the tower bridge at Castaic Lake. The project would install restrainer cables to transfer longitudinal seismic forces to the adjacent spans or frames and the piers would be jacketed with carbon fiber reinforcement. Project implementation would require the lake’s surface elevation be lowered from the normal operation elevation of approximately 1,505 feet above mean sea level (amsl) to 1,380 feet amsl to access project components, such as the piers and abutment structures holding the tower bridge above water level. Project construction is anticipated to take 15.5 months with the drawdown of Castaic Lake taking approximately 10 months.

The IS provides an assessment of the proposed project’s potential significant adverse impacts on the environment. The IS concludes the proposed project would not have any significant adverse effects on the environment after implementation of mitigation measures.

The Initial Study is being circulated for public review and comment for the period of 30 days [April 10, 2020 and ending May 10, 2020].  Written comments should be submitted and received no later than close of business on May 10, 2020 to Kevin Smith with Environmental Science Associates at or the mailing address below.

Kevin Smith
RE: Castaic Dam High Intake Tower Bridge Retrofit
Environmental Science Associates
626 Wilshire Boulevard, Suite 1100
Los Angeles, CA 90017

Copies of the draft IS and proposed MND are available at:
• Castaic Lake Park Headquarters Office: 32132 Castaic Lake Drive, Castaic, CA 91384 from 8 a.m. to 5 p.m. Monday-Friday

In order to comply with COVID-19 social distancing requirements, the IS will be available online and hard copies will be made available upon request.  Please contact Kevin Smith with Environmental Science Associates ( or 805-914-1503) for any questions or for distribution of a hard copy of the IS.