Hyrum Dam is an earth dam located in Cache County, Utah, built in 1935. It carries a High hazard potential classification.
Dam profile
NID height · 116 ft116 ft tall and 540 ft long, taller than 98% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Hyrum Dam
The primary purpose of Hyrum Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bureau of Reclamation (federal). It impounds the Little Bear River near Wellsville.
The dam stands 116 feet tall and stretches 540 feet across, creates a reservoir covering 480 acres, has a maximum storage capacity of 18,685 acre-feet, and collects water from a drainage area of 217 square miles. Completed in 1935, the structure is well-established, with more than 75 years of service.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 08/27/2020.
At 116 feet, this dam is taller than 98% of all dams in the United States.
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 Utah 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 | Utah |
| County | Cache |
| Nearest City | Wellsville |
| River/Stream | Little Bear River |
| Coordinates | 41.62400, -111.87320 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 116 ft |
| Dam Height | 116 ft |
| Dam Length | 540 ft |
| Year Completed | 1935 (91 years old) |
Storage & Hydraulics
| NID Storage | 18,685 acre-ft |
| Max Storage | 18,685 acre-ft |
| Normal Storage | 18,685 acre-ft |
| Surface Area | 480 acres |
| Drainage Area | 217 sq mi |
| Max Discharge | 6,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Bureau of Reclamation |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not assessed |
| Last Inspection | 08/27/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | UT10123 |
| Federal ID | UT10123 |
| More Info | State Dam Safety Program |