Carbone Flood Control Dam Reservoir Report
Last Updated: December 5, 2025
Carbone Flood Control Dam, located in Decker, Montana, serves as a vital component in managing flood risk along the North Fork Spring Creek.
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Summary
Completed in 2002, this earth dam stands at 32 feet in height and spans 2400 feet in length, with a maximum storage capacity of 1050 acre-feet. The dam plays a crucial role in flood risk reduction for the Big Horn County area, with a high hazard potential but a satisfactory condition assessment as of the last inspection in 2020.
Managed by a private entity, Carbone Flood Control Dam is regulated by the Montana Department of Natural Resources and Conservation (DNRC) with state jurisdiction and permitting in place. The dam features an uncontrolled spillway with a width of 25 feet, capable of handling a maximum discharge of 14,300 cubic feet per second. While the risk assessment is moderate, ongoing risk management measures are not specified, highlighting the importance of continued monitoring and maintenance to ensure the dam's effectiveness in flood control.
In the event of an emergency, the dam's Emergency Action Plan (EAP) status is unclear, emphasizing the need for updated emergency contacts and preparedness guidelines. Despite the high hazard potential, Carbone Flood Control Dam remains a critical infrastructure asset for the community, demonstrating the importance of proactive risk assessment and management to safeguard water resources and mitigate potential flood impacts.
Year Completed |
2002 |
Dam Length |
2400 |
Dam Height |
32 |
River Or Stream |
NORTH FORK SPRING CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
21.9 |
Nid Storage |
1050 |
Hazard Potential |
High |
Nid Height |
32 |
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.
Carbone Flood Control Dam