Armstrong Pond Dam Reservoir Report
Last Updated: December 5, 2025
Armstrong Pond Dam, located in Pleasant Mound, Illinois, is a private earth dam constructed in 1974 for recreational purposes.
°F
°F
mph
Wind
%
Humidity
Summary
Standing at a height of 26 feet and with a length of 275 feet, the dam boasts a storage capacity of 96 acre-feet with a normal storage level of 62 acre-feet. Although primarily used for recreation, the dam is also state-regulated by the Illinois Department of Natural Resources, ensuring that it meets inspection, enforcement, and permitting requirements.
With a low hazard potential and a moderate risk assessment rating, Armstrong Pond Dam is considered to be a relatively safe structure. The dam features an uncontrolled spillway and outlet gates, with no associated locks. Despite its relatively low hazard potential, the dam undergoes inspections every five years to ensure its continued safe operation. The last documented inspection of the dam took place in June 2018, with its condition assessment listed as "Not Available."
Water resource and climate enthusiasts may find Armstrong Pond Dam to be an intriguing structure for its unique design features and recreational purpose. As a privately-owned earth dam in the St. Louis District, the dam serves as a testament to the diverse ways in which water resources can be utilized for both practical and leisure purposes. With its state-regulated status and regular inspections, Armstrong Pond Dam stands as a symbol of responsible dam management and safety in the region.
Year Completed |
1974 |
Dam Length |
275 |
Dam Height |
26 |
River Or Stream |
TRIB AVERY BRANCH |
Primary Dam Type |
Earth |
Nid Storage |
96 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
26 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Armstrong Pond Dam