Pinckneyville Reservoir Dam Reservoir Report

Last Updated: December 22, 2025

The Pinckneyville Reservoir Dam, located in Perry County, Illinois, was completed in 1953 and stands at a height of 45 feet with a length of 920 feet.


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Summary

The dam's primary purpose is to supply water, with a maximum storage capacity of 6,565 acre-feet and a normal storage of 2,870 acre-feet. It is situated on the Opossum Creek and serves as a vital water resource for the local community.

Managed by the local government, the dam is regulated by the Illinois Department of Natural Resources and undergoes regular inspections to ensure its safety and functionality. With a significant hazard potential and a moderate risk assessment rating, the dam plays a crucial role in water supply management in the region. Despite limited information on its condition assessment, the dam continues to provide essential water resources for the surrounding area.

As a key infrastructure for water supply, the Pinckneyville Reservoir Dam serves as a critical component in maintaining water security in Perry County, Illinois. With its uncontrolled spillway and significant storage capacity, the dam plays a vital role in managing water resources and mitigating potential risks. As water resource and climate enthusiasts, the dam's history, design, and operational details offer valuable insights into the intersection of infrastructure and environmental stewardship in the region.

Year Completed

1953

Dam Length

920

Dam Height

45

River Or Stream

OPOSSUM CREEK

Primary Dam Type

Earth

Surface Area

202

Drainage Area

6.5

Nid Storage

6565

Outlet Gates

Uncontrolled

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

45
       
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.