Harrell Lake South Dam Reservoir Report
Last Updated: January 12, 2026
Harrell Lake South Dam in Adams County, Illinois, was completed in 1965 and serves as a key recreation site in the area.
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Summary
The earth dam, with a height of 24 feet and a length of 500 feet, creates a reservoir with a storage capacity of 275 acre-feet for recreational activities like boating and fishing. 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 its low hazard potential, the dam is considered to have a moderate risk level, with a risk assessment rating of 3. Emergency preparedness measures, such as an Emergency Action Plan (EAP), are not currently in place for the dam. The spillway, an uncontrolled type with a width of 40 feet, helps manage excess water flow during heavy rainfall events. Overall, Harrell Lake South Dam plays a vital role in providing recreational opportunities for local residents and visitors while also highlighting the importance of proper dam maintenance and risk management in the face of potential climate challenges.
Year Completed |
1965 |
Dam Length |
500 |
Dam Height |
24 |
River Or Stream |
TRIB FIGLEY BRANCH,MCKEE CREEK |
Primary Dam Type |
Earth |
Nid Storage |
275 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
24 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Bear Creek Near Marcelline
|
5cfs |
La Moine River At Ripley
|
48cfs |
La Moine River At Colmar
|
68cfs |
North River At Palmyra
|
11cfs |
South Fabius River Near Taylor
|
12cfs |
Bear Creek At Hannibal
|
5cfs |
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.
Harrell Lake South Dam