Mirror Lake Dam Reservoir Report

Last Updated: December 5, 2025

Mirror Lake Dam, located in Liberty, Michigan, is a privately-owned structure regulated by the Michigan Department of Environment, Great Lakes, and Energy.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1966, this earth dam stands at 21 feet high and spans 865 feet across the Grand River, serving primarily for recreational purposes with a storage capacity of 745 acre-feet. The dam's spillway is uncontrolled, with a width of 19 feet, and it has a significant hazard potential but is currently in satisfactory condition as of the last inspection in October 2020.

With a drainage area of 4.26 square miles and a maximum discharge capacity of 200 cubic feet per second, Mirror Lake Dam plays a crucial role in managing water resources in the region. Its location within the Detroit District of the US Army Corps of Engineers highlights its importance in the local ecosystem. While the dam poses a moderate risk according to the latest assessment, emergency action plans have been prepared to ensure public safety in case of any unforeseen events.

As water resource and climate enthusiasts explore the role of dams in mitigating floods and providing recreational opportunities, Mirror Lake Dam stands as a vital infrastructure in Jackson County. With ongoing state inspections and regulatory oversight, this dam serves as a symbol of responsible water management and environmental stewardship in the region, contributing to the resilience of the local community in the face of changing climate conditions.

Year Completed

1966

Dam Length

865

Dam Height

21

River Or Stream

Grand River

Primary Dam Type

Earth

Surface Area

61

Hydraulic Height

21

Drainage Area

4.26

Nid Storage

745

Structural Height

21

Hazard Potential

Significant

Nid Height

21
       
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.