4-s Ranch Reclamation Reservoir
4-s Ranch Reclamation Reservoir is an earth dam located in San Diego County, California, built in 2000. It carries a High hazard potential classification and has a satisfactory condition assessment.
About 4-s Ranch Reclamation Reservoir
The primary purpose of 4-s Ranch Reclamation 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 Olivenhain Municipal Water District (public utility). It impounds the Artesian Creek near San Diego.
The dam stands 22 feet tall and stretches 1,270 feet across, creates a reservoir covering 13 acres, and has a maximum storage capacity of 410 acre-feet. Completed in 2000, the structure is 26 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 04/03/2025.
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 | San Diego |
| Nearest City | San Diego |
| River/Stream | Artesian Creek |
| Coordinates | 33.01470, -117.11300 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 22 ft |
| Dam Height | 22 ft |
| Dam Length | 1,270 ft |
| Year Completed | 2000 (26 years old) |
Storage & Hydraulics
| NID Storage | 410 acre-ft |
| Max Storage | 410 acre-ft |
| Surface Area | 13 acres |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Olivenhain Municipal Water District |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/03/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA01446 |
| Federal ID | CA01446 |
| More Info | State Dam Safety Program |