Lake Piasa Dam Reservoir Report
Nearby: Craig Lake Dam Olin Pond Dam
Last Updated: December 22, 2025
Lake Piasa Dam in Alton, Illinois, stands as a testament to the intersection of water resource management and climate considerations.
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Summary
Built in 1963 for recreational purposes, the dam spans 515 feet in length and reaches a height of 47 feet, providing storage capacity of 292 acre-feet. The dam, located on Little Piasa Creek-offstream, is state-regulated by the Illinois Department of Natural Resources, with regular inspections ensuring its structural integrity.
Despite its low hazard potential, Lake Piasa Dam holds a moderate risk assessment rating, indicating a need for ongoing monitoring and risk management measures. The dam features an uncontrolled spillway and outlet gates, reflecting its design as an earth dam with a buttress core. While its primary purpose is for recreation, the dam's role in water resource management is crucial for the surrounding community. The dam's location within the Kansas City District underscores its significance in the regional water infrastructure landscape.
Enthusiasts of water resources and climate resilience can appreciate Lake Piasa Dam as a focal point for both recreational enjoyment and environmental stewardship. With its regulated state jurisdiction, regular inspections, and moderate risk assessment, the dam serves as a vital component of the water management infrastructure in Jersey County, Illinois. As climate change impacts continue to shape water resource dynamics, Lake Piasa Dam stands as a symbol of responsible planning and management in the face of evolving environmental challenges.
Year Completed |
1963 |
Dam Length |
515 |
Dam Height |
47 |
River Or Stream |
LITTLE PIASA CREEK-OFFSTREAM |
Primary Dam Type |
Earth |
Nid Storage |
292 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
47 |
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.
Lake Piasa Dam
Mc Adams Highway Jersey County