Heller Lake Dam Reservoir Report
Last Updated: December 19, 2025
Heller Lake Dam, located in Vermont, Illinois, is a private earth dam constructed in 1965 with a primary purpose of recreation.
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Summary
Managed by the USDA NRCS, this dam stands at a height of 22 feet and has a storage capacity of 57 acre-feet, with a normal storage level of 32 acre-feet. The dam, designed in a buttress core type, has an uncontrolled spillway with a width of 50 feet.
Even though Heller Lake Dam is categorized as having a low hazard potential, it is state-regulated by the Illinois Department of Natural Resources (IDNR) and undergoes regular inspections every 5 years. The dam's risk assessment is moderate, with no available condition assessment data. While it lacks certain emergency preparedness features such as an Emergency Action Plan (EAP) and inundation maps, the dam remains an important recreational resource within the area, offering opportunities for water-based activities in a scenic environment along the TRIB OTTER CREEK.
Year Completed |
1965 |
Dam Length |
193 |
Dam Height |
22 |
River Or Stream |
TRIB OTTER CREEK |
Primary Dam Type |
Earth |
Nid Storage |
57 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
22 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Spoon River At Seville
|
161cfs |
La Moine River At Ripley
|
33cfs |
Spoon River At London Mills
|
86cfs |
La Moine River At Colmar
|
17cfs |
Sangamon River Near Oakford
|
356cfs |
Illinois River At Kingston Mines
|
5290cfs |
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.
Heller Lake Dam