Neffs Lake Dam Reservoir Report
Nearby: Rose Lake Dam Frosty Acres Lake Dam
Last Updated: December 5, 2025
Neffs Lake Dam, located in Marion, Illinois, was completed in 1963 by the USDA NRCS with a primary purpose of recreation.
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Summary
This earth dam stands at 22 feet in height and spans 310 feet in length, providing a storage capacity of 56 acre-feet. The dam, situated on the TRIB BEAR BRANCH-OFFSTREAM, is regulated by the Illinois Department of Natural Resources and undergoes state inspections and enforcement measures to ensure its safety and functionality.
With a low hazard potential and a moderate risk assessment, Neffs Lake Dam serves as a vital resource for the community of Wayne City. Although the dam's condition assessment is currently unavailable, its emergency action plan status and risk management measures are not specified. Despite these uncertainties, the dam continues to offer recreational opportunities and contributes to the local water resource management efforts in the region. Enthusiasts of water resources and climate will find Neffs Lake Dam a fascinating structure to explore and study in the context of sustainable development and environmental stewardship.
Year Completed |
1963 |
Dam Length |
310 |
Dam Height |
22 |
River Or Stream |
TRIB BEAR BRANCH-OFFSTREAM |
Primary Dam Type |
Earth |
Nid Storage |
56 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
22 |
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.
Neffs Lake Dam