Whittier Narrows Dam
Whittier Narrows Dam is an earth dam located in Los Angeles County, California, built in 1957. It carries a High hazard potential classification.
About Whittier Narrows Dam
The primary purpose of Whittier Narrows Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Usace - Los Angeles District (federal). It impounds the San Gabriel River near Whittier.
The dam stands 56 feet tall and stretches 16,960 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 66,702 acre-feet, and collects water from a drainage area of 554 square miles. Completed in 1957, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 07/07/2022.
At 56 feet, this dam is taller than 94% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | California |
| County | Los Angeles |
| Nearest City | Whittier |
| River/Stream | San Gabriel River |
| Coordinates | 34.02090, -118.05497 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 56 ft |
| Dam Height | 56 ft |
| Dam Length | 16,960 ft |
| Year Completed | 1957 (69 years old) |
Storage & Hydraulics
| NID Storage | 66,702 acre-ft |
| Max Storage | 66,702 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 554 sq mi |
| Max Discharge | 307,900 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Los Angeles District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 07/07/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA10027 |
| Federal ID | CA10027 |
| More Info | State Dam Safety Program |