Grieves Dam Reservoir Report

Last Updated: December 19, 2025

Grieves Dam, located in Fulton, Illinois, along the TRIB ILLINOIS RIVER, is a privately owned structure designed by MCCLURE ENGINEERING ASSOCIATES.


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Summary

Completed in 1998, this earth dam serves primarily for recreational purposes, offering a serene environment for water resource and climate enthusiasts to explore. With a height of 28 feet and a length of 430 feet, the dam has a storage capacity of 86.4 acre-feet, with a normal storage level of 45.2 acre-feet.

Despite its recreational focus, Grieves Dam also plays a crucial role in managing water resources in the area, with a significant hazard potential and moderate risk level. The dam features uncontrolled spillways and outlet gates, allowing for controlled release of water when necessary. While the dam is state regulated and inspected by the Illinois Department of Natural Resources, its current condition assessment is marked as "Not Available," highlighting the need for ongoing monitoring and maintenance to ensure its safety and effectiveness in the face of changing climate conditions.

In the heart of Illinois, Grieves Dam stands as a testament to the intersection of human ingenuity and natural landscapes, offering a space for both enjoyment and conservation. As water resource and climate enthusiasts continue to explore and engage with this vital structure, its role in the local ecosystem and broader climate resilience efforts becomes increasingly apparent. With its historical significance and ongoing management challenges, Grieves Dam serves as a reminder of the delicate balance between human development and environmental stewardship in the face of a changing climate.

Year Completed

1998

Dam Length

430

Dam Height

28

River Or Stream

TRIB ILLINOIS RIVER

Primary Dam Type

Earth

Surface Area

6

Drainage Area

0.65

Nid Storage

86.4

Outlet Gates

Uncontrolled

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

28
       
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.