Pr-156 Retention Dam Reservoir Report
Nearby: Pr-88 Retention Dam Clausen
Last Updated: December 6, 2025
Pr-156 Retention Dam, located in Hinsdale, Montana, along the Whitewater Creek/Milk River, is a federal-owned structure under the jurisdiction of the Bureau of Land Management.
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Summary
Completed in 1937, this gravity dam serves the primary purpose of flood risk reduction, with a hydraulic height of 16 feet and a structural height of 20 feet. The dam has a storage capacity of 79 acre-feet and covers a surface area of 16 acres, helping to protect the surrounding area from potential flooding events.
Despite being labeled as low hazard potential and not yet rated for condition assessment, Pr-156 Retention Dam plays a crucial role in mitigating flood risks in the region. Operated and maintained by the Bureau of Land Management, the dam stands as a testament to effective water resource management and climate resilience efforts. With a drainage area of 0.3 square miles, the dam is strategically positioned to safeguard the local community and environment from potential water-related hazards.
As enthusiasts of water resources and climate resilience, the Pr-156 Retention Dam serves as a model for effective flood risk reduction infrastructure. With its well-defined purpose, strong design features, and historical significance, this gravity dam showcases the importance of proactive measures in safeguarding communities against the impacts of extreme weather events. The ongoing efforts by the Bureau of Land Management to operate and maintain this vital structure underscore the commitment to water resource management and climate adaptation in the region.
Year Completed |
1937 |
Dam Length |
396 |
River Or Stream |
WHITEWATER CK./MILK RIVER |
Primary Dam Type |
Gravity |
Surface Area |
16 |
Hydraulic Height |
16 |
Drainage Area |
0.3 |
Nid Storage |
79 |
Structural Height |
20 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
20 |
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.
Pr-156 Retention Dam