Calvin Reservoir Report
Nearby: Hansen Lake Dam Katy's Lake Dam
Last Updated: January 11, 2026
Calvin is a private water resource located in Sheridan, Montana, specifically in the city of Medicine Lake.
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Summary
This dam, completed in 1945, serves multiple purposes including fire protection, stock, and as a small fish pond. Its primary source agency is in Montana, and it is regulated by the Department of Natural Resources and Conservation (DNRC). The dam has a height of 15 feet and a maximum storage capacity of 91 acre-feet, with a normal storage capacity of 9 acre-feet.
Situated on the East Brush Mountain Creek, Calvin's low hazard potential poses minimal risk to surrounding areas. The dam's condition is currently not rated, and there is no recent inspection data available. However, it is reassuring to note that the state agency enforces regular inspections, permitting, and maintenance to ensure the safety and functionality of this water resource. Congressional oversight comes from Representative Greg Gianforte (R) in Montana's Congressional District 00.
Water and climate enthusiasts will appreciate Calvin's contribution to local water management, particularly in fire protection and livestock support. With its historical significance dating back to the mid-20th century, Calvin stands as a testament to sustainable water resource development in the region. Despite its low hazard potential, ongoing regulatory oversight and potential future risk management measures will continue to ensure the safety and resilience of this essential water infrastructure in Montana.
Year Completed |
1945 |
Dam Length |
200 |
Dam Height |
15 |
River Or Stream |
EAST BRUSH MOUNTAIN CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Nid Storage |
91 |
Hazard Potential |
Low |
Nid Height |
15 |
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.
Calvin