Little Black River Structure A Reservoir Report
Last Updated: December 5, 2025
Little Black River Structure A, located in Cheboygan, Michigan, is a flood risk reduction dam on the Little Black River.
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Summary
Built in 1962 by the USDA NRCS, this earth dam stands at 34 feet high and has a hydraulic height of 27.5 feet. It spans 350 feet in length and has a storage capacity of 440 acre-feet. The dam is equipped with an uncontrolled spillway that is 303 feet wide, capable of handling a maximum discharge of 11,200 cubic feet per second.
Despite its satisfactory condition assessment as of August 2017, Little Black River Structure A is classified as having a high hazard potential. The dam is regulated by the Michigan Department of Environment, Great Lakes, and Energy (EGLE), with state permitting, inspection, and enforcement activities in place. The primary purpose of the dam is flood risk reduction, serving to protect the surrounding area from potential inundation during periods of high water levels. With a drainage area of 9.7 square miles, the dam plays a crucial role in managing water flow and mitigating flood risks in the region.
In the event of an emergency, it is crucial for stakeholders to have an Emergency Action Plan (EAP) in place. While the last EAP revision dates back to March 1996, the risk assessment for the dam is moderate, indicating a need for ongoing monitoring and management measures to ensure the safety and integrity of Little Black River Structure A. As water resource and climate enthusiasts, understanding the role of dams like this one in safeguarding communities against flooding and water-related hazards is essential for fostering resilience and sustainable water management practices.
Year Completed |
1962 |
Dam Length |
350 |
Dam Height |
34 |
River Or Stream |
Little Black River |
Primary Dam Type |
Earth |
Hydraulic Height |
27.5 |
Drainage Area |
9.7 |
Nid Storage |
440 |
Structural Height |
34 |
Outlet Gates |
None |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
34 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
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