Citizens Lake Dam Reservoir Report
Last Updated: December 18, 2025
Citizens Lake Dam, located in Monmouth, Illinois, was completed in 1878 and is primarily used for recreational purposes.
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Summary
Owned by the local government, this earth dam with a buttress core stands at a height of 20 feet, stretching 353 feet in length. The dam's maximum storage capacity is 73 acre-feet, with a normal storage level of 42 acre-feet, providing ample water resources for the surrounding area.
Managed by the Illinois Department of Natural Resources, Citizens Lake Dam is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and compliance with regulations. Despite its low hazard potential, a moderate risk assessment level of 3 has been assigned to the dam. With an uncontrolled spillway and outlet gates, the dam's emergency action plan status, condition assessment, and risk management measures are currently not available. For water resource and climate enthusiasts, the dam serves as both a historical landmark and a vital recreational asset in Warren County, Illinois.
Year Completed |
1878 |
Dam Length |
353 |
Dam Height |
20 |
River Or Stream |
TRIB CEDAR CREEK |
Primary Dam Type |
Earth |
Nid Storage |
73 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Henderson Creek Near Oquawka
|
45cfs |
Pope Creek Near Keithsburg
|
25cfs |
Spoon River At London Mills
|
86cfs |
Edwards River Near New Boston
|
41cfs |
Edwards River Near Orion
|
66cfs |
Iowa River At Wapello
|
3600cfs |
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.
Citizens Lake Dam