Castle Rock Reservoir Dam Reservoir Report
Last Updated: December 5, 2025
Castle Rock Reservoir Dam, located in Rosebud, Montana, is a vital public utility structure that serves as a key water resource in the region.
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Summary
Completed in 1976, this Earth type dam stands at a height of 67 feet and has a storage capacity of 3540 acre-feet, providing essential water storage for the surrounding area. The dam is situated on the TR-East Fork Armells Creek, with a drainage area of 0.89 square miles, ensuring a reliable water supply for the community.
Managed by the Montana Department of Environmental Quality (DEQ), Castle Rock Reservoir Dam is regularly inspected and regulated to ensure its safety and functionality. With a high hazard potential but a satisfactory condition assessment, the dam plays a critical role in flood control and water management in the region. The dam's emergency action plan is in place to address any potential risks and ensure the safety of nearby residents in the event of an emergency.
With its strategic location and significant water storage capacity, Castle Rock Reservoir Dam plays a crucial role in water resource management in Montana. As a key public utility structure, it provides essential water supply for the community while ensuring safety and compliance with regulatory standards. The dam's continued maintenance and inspection underscore its importance in protecting the surrounding area from potential hazards and ensuring a reliable water source for years to come.
Year Completed |
1976 |
Dam Length |
1095 |
Dam Height |
67 |
River Or Stream |
TR-EAST FORK ARMELLS CREEK |
Primary Dam Type |
Earth |
Surface Area |
140 |
Hydraulic Height |
67 |
Drainage Area |
0.89 |
Nid Storage |
3540 |
Hazard Potential |
High |
Nid Height |
67 |
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.
Castle Rock Reservoir Dam