Vesper Lake Dam Reservoir Report
Last Updated: December 30, 2025
Vesper Lake Dam, located in Madison County, Illinois, is a private-owned structure with a primary purpose of recreation.
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Summary
Constructed in 1955 by the USDA NRCS, this earth dam stands at a height of 24 feet and spans a length of 225 feet along the TRIB CAHOKIA CREEK. With a storage capacity of 54 acre-feet, the dam is regulated by the Illinois Department of Natural Resources and undergoes regular inspections to ensure its safety and compliance with state regulations.
Despite being classified as having a low hazard potential, Vesper Lake Dam poses a moderate risk due to its age and the lack of available condition assessment data. The spillway, which is uncontrolled, has a width of 35 feet, and the outlet gates are also uncontrolled. In case of emergencies, the dam does not have an Emergency Action Plan (EAP) in place, which is a cause for concern. Overall, the risk management measures and guidelines for the dam are not clearly defined, indicating a need for further evaluation and preparation in case of unforeseen events.
For water resource and climate enthusiasts, Vesper Lake Dam serves as an interesting case study in dam management and safety. With its recreational purpose and location in a populated area, the dam's condition and risk assessment are crucial in ensuring the safety of the surrounding community and the preservation of the local ecosystem. As efforts continue to monitor and improve the dam's infrastructure, it will be important to address any potential vulnerabilities and establish comprehensive emergency response plans to mitigate risks and safeguard the environment.
Year Completed |
1955 |
Dam Length |
225 |
Dam Height |
24 |
River Or Stream |
TRIB CAHOKIA CREEK |
Primary Dam Type |
Earth |
Nid Storage |
54 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
24 |
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.
Vesper Lake Dam