Choate Lake Dam Reservoir Report

Last Updated: December 6, 2025

Choate Lake Dam, located in Union, Illinois, serves as a vital water resource and recreational site along Kohler Creek.


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Summary

Built in 1907 with a height of 25 feet and a length of 700 feet, the dam provides a storage capacity of 450 acre-feet and a surface area of 33.5 acres. The primary purpose of Choate Lake Dam is for recreation, with additional benefits for water supply.

With a high hazard potential, Choate Lake Dam is regulated and inspected by the Illinois Department of Natural Resources to ensure its safety and functionality. The dam features an uncontrolled spillway with a width of 46 feet, allowing for a maximum discharge of 673 cubic feet per second. While the condition assessment is not available, the dam is considered to have moderate risk (level 3) and emergency action plans are being evaluated to meet guidelines.

For water resource and climate enthusiasts, Choate Lake Dam offers a fascinating glimpse into the intersection of human engineering and natural ecosystems. As a key feature in the St. Louis District, the dam's historical significance and ongoing management provide valuable insights into the challenges and opportunities of maintaining water infrastructure in a changing climate.

Year Completed

1907

Dam Length

700

Dam Height

25

River Or Stream

KOHLER CREEK

Primary Dam Type

Earth

Surface Area

33.5

Drainage Area

1.1

Nid Storage

450

Outlet Gates

Uncontrolled

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

25
       
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.