Crystal Lake Dam Reservoir Report
Nearby: Kiel Pond Dam Feyerbrand Pond Dam
Last Updated: December 21, 2025
Crystal Lake Dam, located in Alton, Illinois, is a private-owned structure primarily used for recreation.
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Summary
Built in 1954, this earth dam stands at a height of 24 feet and spans 240 feet in length, providing a storage capacity of 87 acre-feet. The dam overlooks the Trib Piasa Creek and is regulated by the Illinois Department of Natural Resources, with regular inspections conducted every 5 years to ensure its safety and functionality.
Despite its low hazard potential, Crystal Lake Dam poses a moderate risk, indicating the importance of ongoing risk management measures. While the condition assessment is not currently available, the dam's emergency action plan status and inundation maps preparation remain undisclosed. Although the spillway is uncontrolled and the outlet gates are also unregulated, the dam's design and construction details such as the core type being buttress and the foundation type being unlisted/unknown, contribute to its structural integrity.
Water resource and climate enthusiasts will find Crystal Lake Dam's history and specifications intriguing, given its role in providing recreational opportunities and water storage in the region. With its picturesque location and regulated operations, this dam serves as a vital component of the local ecosystem while also highlighting the importance of ongoing risk management and safety protocols in dam infrastructure.
Year Completed |
1954 |
Dam Length |
240 |
Dam Height |
24 |
River Or Stream |
TRIB PIASA CREEK |
Primary Dam Type |
Earth |
Nid Storage |
87 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
24 |
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.
Crystal Lake Dam