General Motors Dam Reservoir Report

Last Updated: December 5, 2025

General Motors Dam, also known as Sloan Lake Dam, is a private-owned structure located in Brighton, Michigan.


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Summary

Completed in 1926, this arch-type dam serves primarily for recreational purposes, offering a tranquil setting for visitors to enjoy the surrounding Mann Creek and Sloan Lake. With a height of 13 feet and a length of 380 feet, the dam has a storage capacity of 420 acre-feet and a surface area of 69 acres, making it a significant feature in the area's water resource management.

Managed by the Michigan Department of Environment, Great Lakes, and Energy (DEGLE), General Motors Dam is subject to state regulations, inspections, and enforcement to ensure its safety and functionality. Despite its low hazard potential and satisfactory condition assessment, the dam is monitored regularly, with the last inspection conducted in October 2019. The risk assessment for the dam is moderate, reflecting the need for ongoing risk management measures to mitigate potential hazards and ensure the safety of the surrounding community and environment.

With its picturesque location and historical significance, General Motors Dam remains a vital component of the water infrastructure in Livingston County, Michigan. As a popular spot for outdoor enthusiasts and nature lovers, the dam continues to serve as a recreational hub while upholding safety standards and regulatory compliance. As climate change and water resource challenges continue to impact the region, the management and maintenance of dams like General Motors Dam play a crucial role in sustaining water availability and safeguarding against potential risks in the future.

Year Completed

1926

Dam Length

380

Dam Height

13

River Or Stream

Mann Creek

Primary Dam Type

Arch

Surface Area

69

Hydraulic Height

13

Drainage Area

12.8

Nid Storage

420

Structural Height

13

Hazard Potential

Low

Nid Height

13
       
Seasonal Comparison

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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.