Cohrs Dam Reservoir Report
Nearby: Rager Dam Gochenour Dam
Last Updated: December 13, 2025
Cohrs Dam in Iowa, managed by a private owner, was completed in 2011 and primarily serves to reduce flood risks in the area.
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Summary
Designed by USDA NRCS, the earth dam stands at a height of 36 feet and stretches 600 feet in length. It has a storage capacity of 66 acre-feet and covers a surface area of 4 acres, with a drainage area of 0.24 square miles. The dam is situated in Harrison County, near the city of Missouri Valley, and is regulated and inspected by the Iowa Department of Natural Resources.
The dam also serves secondary purposes such as creating a fish and wildlife pond, stabilizing grades, and providing recreational opportunities. Despite its low hazard potential, the dam's condition has not been rated, and emergency action plans have not been prepared. The spillway width is 20 feet and there are no outlet gates associated with the structure. Overall, Cohrs Dam plays a crucial role in managing water resources and protecting the local community from potential flooding events while also supporting environmental conservation and recreational activities in the area.
Year Completed |
2011 |
Dam Length |
600 |
Dam Height |
36 |
River Or Stream |
Trib to Willow Creek |
Primary Dam Type |
Earth |
Surface Area |
4 |
Drainage Area |
0.24 |
Nid Storage |
66 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
36 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Soldier River At Pisgah
|
112cfs |
Boyer River At Logan
|
417cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Missouri River At Decatur
|
15500cfs |
Maple River At Mapleton
|
323cfs |
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.
Cohrs Dam