The Whittier Narrows Dam Safety Modification Study was completed in June 2019 and work has begun to address deficiencies identified. Issues with the San Gabriel River Spillway gates have been addressed, which was one of the biggest factors driving the dam’s risk the public. The remaining work is to prevent the earthen dam from eroding or failing if overtopped, include placing soil cement on the crest and downstream slope of the embankment and improving the seepage control system with features like trench drains and graded filter/drainage blankets.
Minor construction started in 2021, and larger construction contracts for the dam modification are anticipated to be awarded in 2025 following completion of design work. Major work is anticipated to take between four and five years to complete.
For detailed physical data visit the Reservoir Regulation page. Additional information on Whittier Narrows Dam and Reservoir can be found in the Whittier Narrows Basin Master Plan.
How this will affect the surrounding community
The remainder of the dam safety project is anticipated the have the following impacts during major construction, which is slated for 2025-2029:
- Lincoln Avenue
- Rosemead Boulevard
- Noise, vibration, dust
- Impacts to bike riders, horse riders, walkers
- Streamland Park
- Golf Course
- Sports Arena Drive
- Bicentennial Park
The Corps also engages in routine maintenance activities within the operational areas of the reservoir year round to maintain the operational capacity of the project. As congressionally appropriated funding allows, the Corps works to upgrade aging structures and systems. Annual maintenance activities at U.S. Army Corps of Engineers operated dams include grading of access roads, vegetation removal and an annual safety inspection. In addition, the control house, gates, and all mechanical and electrical equipment are checked at each dam to make sure they are functioning in accordance with the Dam Operations Manual. Graffiti removal, clearing of debris and sediment, and additional repairs are regularly performed to maintain the facility.
Review Upcoming Proposed Actions
To review public notices on our upcoming proposed maintenance activities please visit the Public Notice postings page or click the “Public Notice” link found in the navigational side bar.
Questions, Concerns, Comments?
Let us know by filling out the comment form or click the “Contact” button in the navigation bar and choose Asset Management (Real Estate | Recreation) or Asset Management (Facility Operations | Maintenance) as the recipient.
The appearance of external hyperlinks does not constitute endorsement by the U.S. Army of this Web site or the information, products, or services contained therein. For other than authorized activities such as military exchanges and MWR sites, the U.S. Army does not exercise any editorial control over the information you may find at these locations. Such links are provided consistent with the stated purpose of this Web site.