Upper Stillwater
ROCK CREEK·
Duchesne, Utah·
Built 1986·
Concrete·
285 ft tall
Physical Details
| Dam Height | 285 ft (taller than 94.1% in UT) |
| Dam Length | 2,660 ft |
| Dam Type | Concrete |
| Max Storage | 35.3K acre-ft |
| Normal Storage | 33.1K acre-ft |
| Surface Area | 329 acres |
| Drainage Area | 102 sq mi |
| Max Discharge | 75,000 cfs |
| Year Completed | 1986 (40 years old) |
| NID ID | UT00608 |
Safety Information
High Hazard
Loss of human life is likely if the dam fails
Emergency Action Plan: Yes
Last Inspection: August 19, 2020
State Regulated: No
Ownership
RECLAMATION
Federal Government
Frequently Asked Questions
What is the hazard classification of Upper Stillwater?
Upper Stillwater is classified as High Hazard. Loss of human life is likely if the dam fails.
Who owns Upper Stillwater?
Upper Stillwater is owned by RECLAMATION (Federal Government).
When was Upper Stillwater last inspected?
Upper Stillwater was last inspected on August 19, 2020.
When was Upper Stillwater built?
Upper Stillwater was completed in 1986, making it 40 years old.
Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.