Pr-11 Retention Dam Reservoir Report
Nearby: Isaac Frye #4 Isaac Frye #1
Last Updated: December 5, 2025
Pr-11 Retention Dam in Montana, managed by the Bureau of Land Management, serves as a crucial flood risk reduction structure along Beauchamp Creek and the Missouri River.
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Summary
Completed in 1942, this gravity dam stands at a structural height of 17 feet and has a hydraulic height of 12 feet, with a storage capacity of 529.65 acre-feet. The dam spans 294 feet in length and covers a surface area of 99 acres, providing vital protection to the surrounding Phillips County.
Despite its low hazard potential, Pr-11 Retention Dam undergoes regular inspections every five years to ensure its structural integrity and functionality. The dam's condition is currently rated as "Not Rated," and it meets the guidelines for emergency action plans (EAP) preparation. With its primary purpose being flood risk reduction, this dam plays a crucial role in safeguarding the local community and surrounding areas from potential water-related disasters. Enthusiasts of water resource management and climate resilience will find Pr-11 Retention Dam to be a fascinating example of sustainable infrastructure for mitigating flood risks in the region.
Year Completed |
1942 |
Dam Length |
294 |
River Or Stream |
BEAUCHAMP CK./MISSOURI RIVER(R |
Primary Dam Type |
Gravity |
Surface Area |
99 |
Hydraulic Height |
12 |
Drainage Area |
0.5 |
Nid Storage |
529.65 |
Structural Height |
17 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
17 |
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-11 Retention Dam