Potrero
Potrero is a gravity dam located in Los Angeles County, California, built in 1967. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Potrero
Potrero is a dam in Los Angeles, California. The dam is owned by Westlake Lake Management Association (private). It impounds the Triunfo Canyon Cr near Cornell.
The dam stands 40 feet tall and stretches 730 feet across, creates a reservoir covering 95 acres, has a maximum storage capacity of 1,600 acre-feet, and collects water from a drainage area of 28 square miles. Completed in 1967, 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 03/18/2025.
At 40 feet, this dam is taller than 87% 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 | Cornell |
| River/Stream | Triunfo Canyon Cr |
| Coordinates | 34.13530, -118.82510 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 40 ft |
| Dam Height | 40 ft |
| Dam Length | 730 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 1,600 acre-ft |
| Max Storage | 1,600 acre-ft |
| Surface Area | 95 acres |
| Drainage Area | 28 sq mi |
Ownership & Safety
| Purpose | Other |
| Owner | Westlake Lake Management Association |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 03/18/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00743 |
| Federal ID | CA00743 |
| More Info | State Dam Safety Program |