South Mack Glass Pond Dam Reservoir Report
Last Updated: December 18, 2025
South Mack Glass Pond Dam, located in Oquawka, Illinois, is a private-owned structure designed by USDA NRCS for the primary purpose of serving as a Fish and Wildlife Pond.
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Summary
Built in 1974, this Earth-type dam stands at a height of 29 feet and stretches 200 feet in length, with a storage capacity of 32 acre-feet. It is situated on Henderson Creek N, within the Rock Island District, and is regulated by the Natural Resources Conservation Service.
With a low hazard potential and a moderate risk assessment rating, South Mack Glass Pond Dam plays a crucial role in providing fire protection, stock, and recreational opportunities in the area. Despite its uncontrolled spillway and outlet gates, the dam's condition assessment is not available, highlighting the need for regular inspections and maintenance to ensure its continued safety and functionality. As a significant water resource structure in Warren County, Illinois, this dam serves as a vital component of the local ecosystem and supports various recreational activities for residents and visitors alike.
Year Completed |
1974 |
Dam Length |
200 |
Dam Height |
29 |
River Or Stream |
Henderson Creek N |
Primary Dam Type |
Earth |
Surface Area |
2 |
Drainage Area |
0.12 |
Nid Storage |
32 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
29 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Henderson Creek Near Oquawka
|
45cfs |
Edwards River Near Orion
|
66cfs |
Pope Creek Near Keithsburg
|
25cfs |
Spoon River At London Mills
|
86cfs |
Edwards River Near New Boston
|
41cfs |
Mill Creek At Milan
|
3cfs |
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.
South Mack Glass Pond Dam