South Fork Reservoir
South Fork Reservoir is an earth dam located in Harney County, Oregon, built in 1968. It carries a Significant hazard potential classification.
About South Fork Reservoir
The primary purpose of South Fork Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Tree Top Ranches (private). It impounds the South Fork Malheur River near Riverside.
The dam stands 30 feet tall and stretches 900 feet across, creates a reservoir covering 10 acres, has a maximum storage capacity of 625 acre-feet, and collects water from a drainage area of 14 square miles. Completed in 1968, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. The most recent inspection on record was 10/30/2020.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Oregon |
| County | Harney |
| Nearest City | Riverside |
| River/Stream | South Fork Malheur River |
| Coordinates | 43.23426, -118.33255 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 30 ft |
| Dam Height | 28 ft |
| Dam Length | 900 ft |
| Year Completed | 1968 (58 years old) |
Storage & Hydraulics
| NID Storage | 625 acre-ft |
| Max Storage | 625 acre-ft |
| Normal Storage | 536 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 14 sq mi |
| Max Discharge | 418 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | TREE TOP RANCHES |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not Rated |
| Last Inspection | 10/30/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | OR00498 |
| Federal ID | OR00498 |
| More Info | State Dam Safety Program |