LOCATION AND DESCRIPTION:
The Whittier Narrows Dam project is a flood control project with incidental water conservation. This project is the central element of the Los Angeles County Drainage Area (LACDA) flood control system. The dam was constructed in 1957 and is operated by the U.S. Army Corps of Engineers, Los Angeles District. The project is located at the "Whittier Narrows", a natural gap in the hills that form the southern boundary of the San Gabriel Valley. The Rio Hondo and the San Gabriel River flow through the reservoir flood control basin. Whittier Narrows Dam has dam safety issues requiring a very high urgency of action (DSAC I).
AUTHORIZATION: Flood Control Act of 1941
ACTIVITIES FOR FY 2023: Funds continue relocation of utilities in advance of the dam modification (Contract 1), environmental commitments (Contract 2), and design of a single construction contract for the dam modification and remaining relocation work (Contract 3)
FY 2024 PLANNED ACCOMPLISHMENTS: Funds will be used to complete Contract 1, continue Contract 2, and complete design and Real Estate Certification, including any relocation agreements and Added Work Memoranda of Agreement requested by non-Federal utility owners of Contract 3.
ISSUES AND OTHER INFORMATION: The most recent total project cost estimate update, certified February 4, 2022, affirms that the full $427.4M will not be needed to complete the project. The FY22 Presidents Budget is sufficient and necessary to fully fund the remaining construction contracts including construction management, project closeout and completion*.
The Dam is classified as DSAC I due to dam safety issues that could result in significant loss of life and property damage to a population at risk of over 1.2M. Two dam safety issues are being addressed: foundation erosion that could fail the dam and overtopping of the dam that could lead to failure. A third issue, premature opening of the spillway gates, was addressed through an Interim Risk Reduction Measure completed in 2022.
*The FY22 certified total project costs indicates additional funds are not required to complete the project. Therefore, additional capability is currently zero.
FINANCIAL SUMMARY:
As of: 14 Mar 2023
Construction
Estimated Federal Cost $427,366,000
Estimated Non-Federal Cost $0
Total Estimated Project Cost $427,366,000
Allocation thru FY22 $424,591,000
President's Budget for FY23 $0
Conference Add for FY23 $0
Approve IIJA FY23 $0
Workplan for FY23 $0
President’s Budget for FY24 $0
Balance to Complete After FY24 $2,775,000*
CONGRESSIONAL INTEREST: Senators Butler and Padilla, Representatives Chu (CA-27), Napolitano (CA-32), and Sanchez (CA-38)
U.S. ARMY CORPS OF ENGINEERS – LOS ANGELES DISTRICT
915 WILSHIRE BLVD., SUITE 1109, LOS ANGELES, CA 90017
http://www.spl.usace.army.mil