Union Street Dam Reservoir Report

Last Updated: December 5, 2025

Union Street Dam, also known as Union Dam (Boardman #1), is a local government-owned structure located in Traverse City, Michigan, along the Boardman River.


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Summary

Completed in 1867, this earth and gravity dam stands at a height of 21 feet and spans 250 feet in length. With a primary purpose of recreation, the dam provides storage of up to 11,200 acre-feet and covers a surface area of 350 acres.

Despite its satisfactory condition assessment as of February 2021, Union Street Dam poses a high hazard potential due to its location and design. The dam is regulated and inspected by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) to ensure compliance with state regulations. The controlled spillway, which is 74 feet wide, helps manage water flow and reduce the risk of flooding downstream, although the dam's risk assessment remains very high.

Water resource and climate enthusiasts interested in the Union Street Dam can appreciate its historical significance and recreational value, as well as the ongoing efforts to mitigate potential risks associated with its operation. As a focal point in the Grand Traverse area, this dam serves as a reminder of the importance of maintaining and managing water infrastructure to ensure the safety and well-being of local communities and ecosystems.

Year Completed

1867

Dam Length

250

Dam Height

21

River Or Stream

Boardman River

Primary Dam Type

Earth

Surface Area

350

Hydraulic Height

20

Drainage Area

276

Nid Storage

11200

Structural Height

21

Hazard Potential

High

Nid Height

21
       
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.