Hartenstene Dam Reservoir Report

Last Updated: December 5, 2025

Hartenstene Dam, also known as Ellis Brothers Dam, is a private dam located in Mottville, Michigan, along the Mill Creek.


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Summary

Built in 1912, this earth dam stands at a height of 30 feet and stretches 300 feet in length. With a storage capacity of 950 acre-feet, the dam serves primarily for recreational purposes, offering a surface area of 69 acres for visitors to enjoy.

Managed by the Michigan Department of Environment, Great Lakes, and Energy (DEGLE), Hartenstene Dam has a low hazard potential and is deemed to be in satisfactory condition as of the last inspection in October 2016. Despite its age, the dam continues to provide valuable recreational opportunities to the local community and beyond. The controlled spillway, with a width of 13 feet, helps regulate the flow of water and ensures the safety of the surrounding area.

With Fred Upton as the representative for the area, the dam remains a vital part of the local landscape, offering both recreational benefits and a source of hydraulic control for the Mill Creek watershed. As climate and water resource enthusiasts, the conservation and maintenance of structures like Hartenstene Dam are crucial in ensuring the sustainability of our water systems and the protection of our natural environment.

Year Completed

1912

Dam Length

300

Dam Height

30

River Or Stream

Mill Creek

Primary Dam Type

Earth

Surface Area

69

Hydraulic Height

30

Drainage Area

44

Nid Storage

950

Structural Height

30

Hazard Potential

Low

Nid Height

30
       
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.