Cottonwood Wash Detention Basin Reservoir Report
Last Updated: December 5, 2025
Located in Richfield, Utah, the Cottonwood Wash Detention Basin is a crucial infrastructure designed for flood risk reduction along the Cottonwood Wash river.
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Summary
Owned and regulated by the Utah Division of Water Rights, this local government-operated detention basin was completed in 1986 and has a hydraulic height of 45 feet, with a structural height of 50 feet. With a storage capacity of 820 acre-feet and a drainage area of 20 square miles, this earth-type dam plays a vital role in protecting the surrounding area from potential flooding events.
The Cottonwood Wash Detention Basin has a high hazard potential but is currently assessed to be in satisfactory condition, as of the last inspection in May 2020. The basin operates under the oversight of the Utah Division of Water Rights, ensuring regular inspections and enforcement of safety measures. With a primary purpose of flood risk reduction, this structure serves as a critical line of defense against flooding in the region. The basin's location at 24,23S~3W SL makes it a key asset in the flood management infrastructure of Sevier County, Utah.
With a maximum discharge capacity of 194 cubic feet per second, the Cottonwood Wash Detention Basin stands as a testament to effective water resource management in the face of climatic challenges. Its strategic design and operational efficiency highlight the importance of proactive flood risk reduction measures in safeguarding communities and infrastructure against the impacts of extreme weather events. As climate change continues to pose threats to water resources, the role of structures like the Cottonwood Wash Detention Basin becomes increasingly vital in ensuring resilience and safety for the residents of Richfield and the surrounding areas.
Year Completed |
1986 |
Dam Length |
4500 |
River Or Stream |
COTTONWOOD WASH |
Primary Dam Type |
Earth |
Hydraulic Height |
45 |
Drainage Area |
20 |
Nid Storage |
820 |
Structural Height |
50 |
Hazard Potential |
High |
Nid Height |
50 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Cottonwood Wash Detention Basin