Long Lake Control Structure Reservoir Report

Last Updated: December 5, 2025

The Long Lake Control Structure, located in Brighton, Michigan, is a gravity dam built in 1951 primarily for recreational purposes.


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Summary

With a height of 7.7 feet and a hydraulic height of 5.8 feet, this structure serves as a key feature along the South Ore Creek, offering a storage capacity of 400 acre-feet and a normal storage level of 230 acre-feet. Despite its low hazard potential, the dam's condition assessment in 2018 revealed poor maintenance, indicating a need for potential improvements to ensure its long-term functionality and safety.

Although the Long Lake Control Structure does not fall under state jurisdiction or regulation, its significance lies in providing recreational opportunities and maintaining water levels for the surrounding area. The dam's spillway type is uncontrolled, with a width of 38 feet, allowing for a maximum discharge of 185 cubic feet per second. While the risk assessment categorizes the structure as moderate, there is room for enhancement in terms of condition assessment, emergency action planning, and risk management measures to address any potential safety concerns and ensure the sustainable use of this water resource for future generations of climate and water enthusiasts.

Year Completed

1951

Dam Length

50

Dam Height

7.7

River Or Stream

South Ore Creek

Primary Dam Type

Gravity

Surface Area

146

Hydraulic Height

5.8

Drainage Area

4.3

Nid Storage

400

Structural Height

7.7

Hazard Potential

Low

Nid Height

8
       
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.