Nankin Mill Dam Reservoir Report

Last Updated: December 5, 2025

Nankin Mill Dam, located in Westland, Michigan, along the M Br River Rouge, is a gravity dam constructed in 1921 primarily for recreational purposes.


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Summary

Standing at a height of 17 feet and stretching 600 feet in length, this dam provides a storage capacity of 140 acre-feet and covers a surface area of 25 acres. With a drainage area of 62.88 square miles, the dam has a maximum discharge capacity of 2340 cubic feet per second.

Despite its satisfactory condition assessment as of January 2018, Nankin Mill Dam poses a high hazard potential due to its location and structural features. The dam is regulated by the Michigan Department of Environment, Great Lakes, and Energy (EGLE), with state permitting, inspection, and enforcement in place to ensure its safety and compliance with regulations. The dam's emergency action plan, last revised in May 2016, reflects a very high risk assessment, emphasizing the need for ongoing risk management measures and preparedness.

As a popular spot for recreation and leisure activities in Wayne County, Nankin Mill Dam serves as a vital piece of infrastructure for the local community. Its controlled spillway, measuring 73 feet in width, helps manage water flow and mitigate potential flooding risks. With a designated emergency contact plan and regular inspection schedule, the dam continues to provide both functional and recreational benefits while maintaining a focus on safety and risk management in the face of changing climate conditions.

Year Completed

1921

Dam Length

600

Dam Height

17

River Or Stream

M Br River Rouge

Primary Dam Type

Gravity

Surface Area

25

Hydraulic Height

17

Drainage Area

62.88

Nid Storage

140

Structural Height

17

Hazard Potential

High

Nid Height

17
       
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.