Erity Dam Reservoir Report

Last Updated: December 5, 2025

Erity Dam, located in Beverly Hills, Michigan, along the River Rouge, was completed in 1913 and serves primarily for recreational purposes.


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Summary

This gravity dam stands at a height of 16 feet with a length of 320 feet, providing a surface area of 27 acres and a drainage area of 41 square miles. Despite its low hazard potential, the dam's condition assessment in 2012 was deemed poor, highlighting the need for maintenance and potential upgrades to ensure the safety of the surrounding community and environment.

Managed by the local government, Erity Dam is regulated by the Michigan Department of Environment, Great Lakes, and Energy (DEGLE), with state permitting, inspection, and enforcement in place. With a maximum storage capacity of 200 acre-feet and a normal storage of 150 acre-feet, the dam can discharge up to 800 cubic feet per second through its uncontrolled spillway. While the risk assessment categorizes the dam as moderate, ongoing risk management measures are essential to mitigate any potential hazards and ensure the long-term resilience of the structure.

In light of its historical significance and crucial role in providing recreational opportunities, Erity Dam stands as a vital piece of infrastructure in Oakland County, Michigan. As water resource and climate enthusiasts, it is imperative to monitor and support efforts to maintain and improve the dam's condition, safeguarding its integrity for future generations to enjoy and benefit from.

Year Completed

1913

Dam Length

320

Dam Height

16

River Or Stream

River Rouge

Primary Dam Type

Gravity

Surface Area

27

Hydraulic Height

16

Drainage Area

41

Nid Storage

200

Structural Height

16

Hazard Potential

Low

Nid Height

16
       
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.