Cowan Dam Reservoir Report
Nearby: Gene Huft Harold Meyer
Last Updated: December 13, 2025
Located in Corson, South Dakota, Cowan Dam stands as a crucial water resource management structure along the TRIB-COTTONWOOD CREEK.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1969, this earth dam reaches a height of 30 feet and spans 334 feet in length, with a storage capacity of 50 acre-feet. Despite its low hazard potential and a current condition assessment of "Not Rated," Cowan Dam is subject to state regulation, inspection, and enforcement by the South Dakota Department of Environment and Natural Resources (DENR).
Owned privately, Cowan Dam plays a pivotal role in flood control, irrigation, and water supply in the surrounding area. With a normal storage capacity of 35 acre-feet and a maximum discharge capability of 3994 cubic feet per second, this dam ensures the efficient management of water resources for both agricultural and environmental purposes. While its Emergency Action Plan (EAP) status is currently unspecified, Cowan Dam remains a key feature in the region's water resource infrastructure.
As climate change continues to impact water resources and availability, the significance of structures like Cowan Dam in ensuring sustainable water management cannot be understated. With its strategic location and functional design, Cowan Dam serves as a vital component in safeguarding the region's water supply and mitigating potential risks associated with extreme weather events. As water resource and climate enthusiasts, understanding the role and regulation of dams like Cowan Dam is crucial in advancing our efforts towards a more resilient and sustainable water future.
Year Completed |
1969 |
Dam Length |
334 |
Dam Height |
30 |
River Or Stream |
TRIB-COTTONWOOD CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
30 |
Nid Storage |
50 |
Hazard Potential |
Low |
Nid Height |
30 |
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.
Cowan Dam