Hennepin Station West Ash Pond Dam Reservoir Report
Last Updated: December 14, 2025
Hennepin Station West Ash Pond Dam in Putnam, Illinois, is a significant earth dam owned by a public utility with state regulation and oversight by the IDNR.
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Summary
This dam serves a primary purpose that falls under the category of "Other" and is classified as an earth dam with a buttress core type. Although specific details regarding its height, volume, and completion year are not provided, the dam's hazard potential is deemed significant, with a moderate risk assessment rating.
Located in the Rock Island District, this dam has a spillway type classified as "Uncontrolled" and has a spillway width of 0. The last inspection was conducted in November 2020, with a frequency of 3 years. While the condition assessment is listed as "Not Available," the emergency action plan (EAP) was last revised in December 2018, indicating a commitment to preparedness and safety measures. Overall, the risk associated with this dam is considered moderate, highlighting the importance of ongoing monitoring and management to ensure the safety of the surrounding area and water resources.
Primary Dam Type |
Earth |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
East Bureau Creek Near Bureau
|
2cfs |
Big Bureau Creek At Princeton
|
8cfs |
Illinois River At Henry
|
6710cfs |
Vermilion River Near Leonore
|
17cfs |
Fox River At Dayton
|
1040cfs |
Illinois River At Marseilles
|
4200cfs |
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.
Hennepin Station West Ash Pond Dam