John Cowan Dam Reservoir Report
Last Updated: January 5, 2026
John Cowan Dam, also known as Cowan Lake Dam, is a privately owned structure located in Stoddard, Missouri.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1980, this earth dam stands at a height of 27 feet and serves primarily for flood risk reduction and grade stabilization along the TR-POPLAR BRANCH stream. With a storage capacity of 36 acre-feet and a surface area of 7 acres, the dam plays a crucial role in protecting the surrounding area from potential flooding events.
Managed by the St. Louis District of the US Army Corps of Engineers, John Cowan Dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment. Despite its moderate risk level, the dam has not been inspected recently and lacks an emergency action plan. With a maximum discharge capacity of 380 cubic feet per second, the dam's uncontrolled spillway and lack of outlet gates may present challenges in managing potential overflow during extreme weather events.
Although John Cowan Dam may not be as well-regulated or inspected as some other dams in the region, its presence is crucial for mitigating flood risks and stabilizing the surrounding area. As water resource and climate enthusiasts, it is important to monitor the condition of this infrastructure and advocate for necessary maintenance and emergency preparedness measures to ensure the safety and functionality of John Cowan Dam for years to come.
Year Completed |
1980 |
Dam Length |
400 |
Dam Height |
27 |
River Or Stream |
TR-POPLAR BRANCH |
Primary Dam Type |
Earth |
Surface Area |
7 |
Hydraulic Height |
27 |
Drainage Area |
96 |
Nid Storage |
36 |
Structural Height |
27 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
27 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Little River Ditch No. 1 Near Morehouse
|
105cfs |
Castor River At Zalma
|
169cfs |
St. Francis River At Wappapello
|
245cfs |
Mississippi River At Thebes
|
91700cfs |
Black River At Poplar Bluff
|
562cfs |
St. Francis River Near Patterson
|
235cfs |
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.
John Cowan Dam