Upper
Upper is an earth dam located in Washakie County, Wyoming, built in 1922. It carries a Low hazard potential classification and has a poor condition assessment.
About Upper
The primary purpose of Upper is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Rice Ranch, Inc (private). It impounds the Spring Branch Brokenback Cr near Manderson.
The dam stands 15 feet tall and stretches 600 feet across, creates a reservoir covering 36 acres, and has a maximum storage capacity of 373 acre-feet. Completed in 1922, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 04/15/2025.
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Location
| State | Wyoming |
| County | Washakie |
| Nearest City | Manderson |
| River/Stream | Spring Branch Brokenback Cr |
| Coordinates | 44.15620, -107.46990 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 600 ft |
| Year Completed | 1922 (104 years old) |
Storage & Hydraulics
| NID Storage | 373 acre-ft |
| Max Storage | 373 acre-ft |
| Normal Storage | 125 acre-ft |
| Surface Area | 36 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Rice Ranch, Inc |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 04/15/2025 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY01065 |
| Federal ID | WY01065 |
| More Info | State Dam Safety Program |