Palisades Reservoir is an earth dam located in Orange County, California, built in 1963. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 146 ft146 ft tall and 620 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Palisades Reservoir
The primary purpose of Palisades Reservoir is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by South Coast Water District (public utility). It impounds the Offstream near San Clemente.
The dam stands 146 feet tall and stretches 620 feet across, creates a reservoir covering 6 acres, has a maximum storage capacity of 147 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1963, 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 04/02/2025.
At 146 feet, this dam is taller than 99% of all dams in the United States.
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 | Orange |
| Nearest City | San Clemente |
| River/Stream | Offstream |
| Coordinates | 33.46380, -117.65220 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 146 ft |
| Dam Height | 146 ft |
| Dam Length | 620 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 147 acre-ft |
| Max Storage | 147 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | South Coast Water District |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/02/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00843 |
| Federal ID | CA00843 |
| More Info | State Dam Safety Program |