Herrin Reservoir 1 Dam Reservoir Report

Last Updated: December 5, 2025

Herrin Reservoir 1 Dam, located in Williamson County, Illinois, is a local government-owned structure primarily used for recreation purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam, completed in 1915, stands at a height of 6 feet and has a length of 489 feet, with a maximum storage capacity of 271 acre-feet. Situated on the TRIB HURRICANE stream, the dam has an uncontrolled spillway with a width of 19 feet and is regulated by the Illinois Department of Natural Resources.

Despite its age, Herrin Reservoir 1 Dam is classified as having a significant hazard potential, with a moderate risk assessment rating of 3. The dam has a history of regular inspections, with the most recent one conducted in June 2017. While the condition assessment is not currently available, the dam's emergency action plan status and risk management measures are not specified in the data provided. Overall, Herrin Reservoir 1 Dam serves as a crucial recreational resource in the area, demonstrating the importance of proper maintenance and monitoring for water resource and climate enthusiasts.

This Earth-type dam, featuring a buttress core design, plays a vital role in providing recreational opportunities for the community. However, its significant hazard potential underscores the importance of ongoing maintenance and risk management to ensure the safety of nearby residents and visitors. With a moderate risk assessment rating, Herrin Reservoir 1 Dam serves as a reminder of the importance of sustainable water resource management practices in the face of changing climate conditions.

Year Completed

1915

Dam Length

489

Dam Height

6

River Or Stream

TRIB HURRICANE

Primary Dam Type

Earth

Nid Storage

271

Outlet Gates

Uncontrolled

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

6
       
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.