Mt Tunnels Tailings Dam Reservoir Report

Last Updated: December 22, 2025

Mt Tunnels Tailings Dam in Jefferson, Montana, is a privately-owned structure regulated by the state's Department of Environmental Quality.


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Summary

The dam, with a surface area of 256 square meters, was completed for the primary purpose of tailings storage. Despite lacking specific data on its height, volume, and other technical details, the dam has been assessed as being in satisfactory condition as of June 2018.

Located at coordinates 46.362143 latitude and -112.112989 longitude, Mt Tunnels Tailings Dam is under the jurisdiction of the state and is subject to regular inspections and enforcement measures by the DEQ. With a high hazard potential, it is crucial for water resource and climate enthusiasts to monitor the dam's condition closely. While specific information on the dam's design and construction is unavailable, it is known that it falls under the oversight of the Mine Safety and Health Administration for regulatory and inspection purposes.

The dam's emergency preparedness, including the existence of an Emergency Action Plan and the availability of inundation maps, remains unclear. However, the satisfactory condition assessment and state regulation provide some assurance of its stability. As a point of interest for those interested in water resources and climate, Mt Tunnels Tailings Dam serves as a reminder of the importance of proper monitoring and maintenance of critical infrastructure to prevent any potential environmental disasters.

Surface Area

256

Hazard Potential

High
       
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.