Bullfrog Lake Dam Reservoir Report

Last Updated: December 5, 2025

Bullfrog Lake Dam, located in Lemont, Illinois, is a local government-owned structure that serves as a recreational area for water resource and climate enthusiasts.


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Summary

Built in 1958, this earth dam stands at a height of 17 feet and spans 700 feet along the Trib Des Plaines River. With a storage capacity of 144 acre-feet, it offers opportunities for outdoor activities such as fishing, boating, and hiking in the surrounding area.

Managed by the Illinois Department of Natural Resources (IDNR), Bullfrog Lake Dam is regulated, permitted, inspected, and enforced by the state to ensure its safety and functionality. While the dam's hazard potential is considered significant, its risk assessment is moderate, indicating a level of awareness and preparedness for any potential emergencies. The dam lacks available condition assessment data, but regular inspections are conducted every three years to monitor its structural integrity and address any maintenance needs.

Despite its uncontrolled spillway type and limited outlet gates, Bullfrog Lake Dam remains a popular destination for nature enthusiasts seeking outdoor recreation in Cook County, Illinois. Its strategic location and proximity to the Des Plaines River offer visitors a chance to connect with nature and enjoy the serenity of the surrounding landscape. As a vital part of the local ecosystem, this dam serves as a hub for water-based activities and wildlife habitat preservation, making it a valuable asset for the community and a must-visit spot for water resource and climate enthusiasts.

Year Completed

1958

Dam Length

700

Dam Height

17

River Or Stream

TRIB DES PLAINES RIVER

Primary Dam Type

Earth

Nid Storage

144

Outlet Gates

None

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

17
       
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.