Johnson Sauk Trail Lake Dam Reservoir Report

Last Updated: January 11, 2026

Johnson Sauk Trail Lake Dam, located in Mineral, Illinois, is a state-regulated earth dam built in 1956 for recreational purposes.


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Summary

The dam stands at 38 feet high and spans a length of 563 feet, with a storage capacity of 752 acre-feet and a spillway width of 66 feet. Situated on the TRIB King Creek, the dam's primary designer is Robert Anderson Engineers, ensuring its structural integrity and safety for visitors.

Managed by the Illinois Department of Natural Resources (IDNR), Johnson Sauk Trail Lake Dam has a low hazard potential and a moderate risk assessment rating. While the condition assessment is currently not available, the dam undergoes regular inspections every five years to ensure its continued safety and functionality. With its uncontrolled spillway and outlet gates, the dam provides essential flood control and recreational opportunities for the surrounding community, making it a vital water resource in the region.

Enthusiasts of water resources and climate will appreciate the ecological significance of Johnson Sauk Trail Lake Dam, which not only offers a picturesque recreational area but also serves as a crucial infrastructure for water management in Henry County, Illinois. With its historical significance and continued maintenance by state regulators, the dam stands as a testament to sustainable water resource management and environmental stewardship in the region.

Year Completed

1956

Dam Length

563

Dam Height

38

River Or Stream

TRIB KING CREEK

Primary Dam Type

Earth

Nid Storage

752

Outlet Gates

Uncontrolled

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

38
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.