Cottonwood Wash Detention Basin
Cottonwood Wash Detention Basin is an earth dam located in Sevier County, Utah, built in 1986. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Cottonwood Wash Detention Basin
The primary purpose of Cottonwood Wash Detention 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 Richfield City Corporation (local government). It impounds the Cottonwood Wash near Richfield.
The dam stands 50 feet tall and stretches 4,500 feet across, has a maximum storage capacity of 820 acre-feet, and collects water from a drainage area of 20 square miles. Completed in 1986, the structure is 40 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 04/27/2022.
At 50 feet, this dam is taller than 93% of dams nationwide.
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 | Sevier |
| Nearest City | Richfield |
| River/Stream | Cottonwood Wash |
| Coordinates | 38.78684, -112.08410 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Length | 4,500 ft |
| Year Completed | 1986 (40 years old) |
Storage & Hydraulics
| NID Storage | 820 acre-ft |
| Max Storage | 820 acre-ft |
| Normal Storage | 695 acre-ft |
| Drainage Area | 20 sq mi |
| Max Discharge | 194 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | RICHFIELD CITY CORPORATION |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/27/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | UT00644 |
| Federal ID | UT00644 |
| More Info | State Dam Safety Program |