Sherman Mine Wastewater Reservoir Report

Last Updated: December 5, 2025

Sherman Mine Wastewater, located in St.


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Summary

Louis County, Minnesota, is a privately owned tailings dam constructed in 1953 with a primary purpose of storing tailings. The dam stands at a height of 20 feet and spans a length of 3200 feet, providing a storage capacity of 115 acre-feet. The dam is regulated by the Minnesota Department of Natural Resources and undergoes regular inspections to ensure compliance with state regulations.

Despite being classified as a low hazard potential structure, Sherman Mine Wastewater has not been rated for its condition assessment. The dam's last inspection was conducted in August 2019, with an inspection frequency of every 8 years. While the dam does not have an Emergency Action Plan (EAP) in place, it meets state permitting and inspection requirements. The dam's emergency contacts, risk assessment, and management measures are currently not documented.

Water resource and climate enthusiasts may be interested in monitoring the maintenance and regulatory oversight of Sherman Mine Wastewater to ensure the safe containment of tailings and the protection of nearby water resources. The dam's location near Dempsey Creek-TR and its low hazard potential highlight the importance of ongoing monitoring and adherence to state regulations to prevent any potential environmental impact from wastewater discharge.

Year Completed

1953

Dam Length

3200

Dam Height

20

River Or Stream

DEMPSEY CREEK-TR

Primary Dam Type

Earth

Surface Area

196

Drainage Area

0.5

Nid Storage

115

Structural Height

20

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

20
       
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.