Lopez Dam
Lopez Dam is an earth dam located in Los Angeles County, California, built in 1954. It carries a High hazard potential classification.
About Lopez Dam
The primary purpose of Lopez Dam is debris control. The dam is designed to catch sediment, rocks, and debris carried by flowing water — particularly important in areas prone to mudslides or heavy erosion. The dam is owned by Usace - Los Angeles District (federal). It impounds the Pacoima Wash near Los Angeles.
The dam stands 50 feet tall and stretches 1,300 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 209 acre-feet, and collects water from a drainage area of 34 square miles. Completed in 1954, 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 02/27/2024.
At 50 feet, this dam is taller than 93% 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 | Los Angeles |
| River/Stream | Pacoima Wash |
| Coordinates | 34.30401, -118.41039 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Height | 50 ft |
| Dam Length | 1,300 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 209 acre-ft |
| Max Storage | 209 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 34 sq mi |
| Max Discharge | 32,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Debris Control |
| Owner | USACE - Los Angeles District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 02/27/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA10020 |
| Federal ID | CA10020 |
| More Info | State Dam Safety Program |