Prenda
Prenda is an earth dam located in Riverside County, California, built in 1954. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Prenda
The primary purpose of Prenda 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 Riverside County Flood Control And Water Conservation District (local government). It impounds the Prenda Creek near Allessandro Heights.
The dam stands 44 feet tall and stretches 1,313 feet across, creates a reservoir covering 15 acres, has a maximum storage capacity of 192 acre-feet, and collects water from a drainage area of 1 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. 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 12/02/2025.
At 44 feet, this dam is taller than 90% 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 | Riverside |
| Nearest City | Allessandro Heights |
| River/Stream | Prenda Creek |
| Coordinates | 33.91240, -117.37070 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 44 ft |
| Dam Height | 44 ft |
| Dam Length | 1,313 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 192 acre-ft |
| Max Storage | 192 acre-ft |
| Surface Area | 15 acres |
| Drainage Area | 1 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Riverside County Flood Control and Water Conservation District |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/02/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00799 |
| Federal ID | CA00799 |
| More Info | State Dam Safety Program |