Winkum Dam Reservoir Report
Nearby: Sob Detention Dam Long Horn #1 Dam
Last Updated: December 20, 2025
Located in Valley County, Montana, Winkum Dam stands as a testament to the ingenuity and engineering prowess of the Bureau of Land Management.
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Summary
This gravity dam, constructed by the BLM, spans 774 feet and boasts a hydraulic height of 22 feet, with a structural height of 28 feet. The dam's reservoir has a storage capacity of 72.62 acre-feet, providing essential water resources for the surrounding area.
Situated on the Middle Fork Lone Tree Creek, Winkum Dam plays a crucial role in regulating water flow and ensuring water security for the region. With a low hazard potential and satisfactory condition assessment, this dam is a vital piece of infrastructure that contributes to the overall water management efforts in Montana. Although the dam's primary purpose is unspecified, its strategic location and design underscore its importance in safeguarding water resources and mitigating potential risks associated with flooding.
Despite its uncontrolled spillway type, Winkum Dam remains a reliable and essential structure maintained by the Bureau of Land Management. With moderate risk assessment and regular inspections, the dam continues to serve its purpose effectively. As a key component in the water infrastructure of Valley County, Winkum Dam symbolizes the commitment to water resource management and climate resilience in the region.
Dam Length |
774 |
River Or Stream |
MIDDLE FORK LONE TREE CREEK |
Primary Dam Type |
Gravity |
Surface Area |
11.22 |
Hydraulic Height |
22 |
Drainage Area |
0.3 |
Nid Storage |
72.62 |
Structural Height |
28 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
28 |
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.
Winkum Dam