Smith Lake Dam Reservoir Report

Last Updated: December 22, 2025

Smith Lake Dam, located in Alton, Illinois, is a private dam constructed in 1966 by the USDA NRCS.


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Summary

With a primary purpose of recreation, this earth dam stands at a height of 37 feet and spans 300 feet in length. The dam's maximum storage capacity is 85 acre-feet, with a normal storage level of 60 acre-feet, making it a valuable resource for water recreation enthusiasts.

Managed by the Illinois Department of Natural Resources, Smith Lake Dam is regulated, permitted, inspected, and enforced by state authorities. The dam's hazard potential is considered low, with a moderate risk assessment rating. While the condition assessment is not available, the dam's emergency action plan status and risk management measures are currently unspecified. Despite its uncontrolled spillway and outlet gates, Smith Lake Dam continues to provide a safe and enjoyable environment for water activities along the Trib Little Piasa Creek.

Overall, Smith Lake Dam serves as a vital water resource in Jersey County, Illinois, offering recreational opportunities and contributing to the local ecosystem. With its picturesque location and well-maintained structure, the dam is a popular destination for outdoor enthusiasts seeking a peaceful retreat by the water. As climate change continues to impact water resources, the importance of maintaining and monitoring dams like Smith Lake becomes increasingly crucial for sustainable water management and environmental conservation efforts in the region.

Year Completed

1966

Dam Length

300

Dam Height

37

River Or Stream

TRIB LITTLE PIASA CREEK

Primary Dam Type

Earth

Nid Storage

85

Outlet Gates

Uncontrolled

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

37
       
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.