Manson Heights Dams Reservoir Report
Nearby: Bruington Lake Dam Spoon Lake Dam
Last Updated: December 14, 2025
Manson Heights Dams, also known as Manson Heights Lake, are privately owned dams located in Maquon, Illinois.
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Summary
Constructed in 1950, these earth dams have a height of 25 feet and a storage capacity of 300 acre-feet, primarily serving for recreational purposes. Situated on the TRIB SUGAR CREEK, these dams are regulated, permitted, inspected, and enforced by the Illinois Department of Natural Resources (IDNR), ensuring their safety and compliance with state regulations.
With a surface area of 26 acres and a drainage area of 0.3 square miles, Manson Heights Dams have a low hazard potential and a moderate risk assessment. The spillway type is uncontrolled, and the outlet gates are also uncontrolled. The last inspection was conducted in September 2018, with a regular inspection frequency of every 5 years. While the condition assessment is currently unavailable, the dams meet state guidelines and are equipped with emergency action plans to mitigate any potential risks.
Despite the dams' private ownership, they play a crucial role in providing recreational opportunities for the local community and visitors. The dams offer a serene environment for activities such as fishing, boating, and picnicking, making Manson Heights Dams a valuable asset in the landscape of Knox County, Illinois, for water resource and climate enthusiasts to enjoy and appreciate.
Year Completed |
1950 |
Dam Height |
25 |
River Or Stream |
TRIB SUGAR CREEK |
Primary Dam Type |
Earth |
Surface Area |
26 |
Drainage Area |
0.3 |
Nid Storage |
300 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Indian Creek Near Wyoming
|
12cfs |
Spoon River At London Mills
|
79cfs |
Edwards River Near Orion
|
66cfs |
Illinois River At Kingston Mines
|
4770cfs |
Spoon River At Seville
|
111cfs |
Green River Near Geneseo
|
185cfs |
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.
Manson Heights Dams