Orchard Estates Retarding Basin
Orchard Estates Retarding Basin is an earth dam located in Orange County, California, built in 1999. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Orchard Estates Retarding Basin
The primary purpose of Orchard Estates Retarding Basin 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 County Of Orange (local government). It impounds the Tr Rattlesnake Can near Northwood Point.
The dam stands 21 feet tall and stretches 810 feet across, creates a reservoir covering 11 acres, has a maximum storage capacity of 138 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1999, the structure is 27 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 09/09/2025.
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 | Orange |
| Nearest City | Northwood Point |
| River/Stream | Tr Rattlesnake Can |
| Coordinates | 33.73840, -117.74670 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 21 ft |
| Dam Height | 21 ft |
| Dam Length | 810 ft |
| Year Completed | 1999 (27 years old) |
Storage & Hydraulics
| NID Storage | 138 acre-ft |
| Max Storage | 138 acre-ft |
| Surface Area | 11 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | County of Orange |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/09/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA01436 |
| Federal ID | CA01436 |
| More Info | State Dam Safety Program |