Coffeen Southwest Detention Pond Dam Reservoir Report
Last Updated: December 5, 2025
Located in Greenville, Illinois, the Coffeen Southwest Detention Pond Dam is a vital structure designed by Hanson Professional Services, Inc.
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Summary
to mitigate flood risks along the Trib McDavid Branch river. Completed in 2010, this earth dam stands at a height of 23 feet and stretches 350 feet in length, providing storage capacity of 86.6 acre-feet to manage floodwaters in the area. With a spillway width of 53 feet and a maximum discharge of 84.8 cubic feet per second, the dam plays a crucial role in reducing the risk of flooding in Montgomery County.
Managed by a public utility, this dam is state-regulated by the Illinois Department of Natural Resources, ensuring that it meets all necessary inspection, enforcement, and permitting requirements. While its hazard potential is classified as low, its risk assessment is moderate, indicating the importance of ongoing monitoring and maintenance to safeguard against potential hazards. Despite its low hazard potential, the dam's purpose of flood risk reduction underscores its critical role in protecting the surrounding community and environment from the impacts of extreme weather events.
Through its construction and operation, the Coffeen Southwest Detention Pond Dam exemplifies the intersection of water resource management and climate resilience. As climate change continues to amplify the frequency and intensity of extreme weather events, structures like this earth dam are essential for safeguarding communities and ecosystems against the threats of flooding. With its strategic location and design features, this dam serves as a beacon of resilience in the face of a changing climate, highlighting the importance of sustainable water resource management practices for a more secure and resilient future.
Year Completed |
2010 |
Dam Length |
350 |
Dam Height |
23 |
River Or Stream |
TRIB MCDAVID BRANCH |
Primary Dam Type |
Earth |
Surface Area |
4.95 |
Drainage Area |
0.15 |
Nid Storage |
86.6 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
23 |
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.
Coffeen Southwest Detention Pond Dam