Wilson (Judith Basin) Reservoir Report
Nearby: Wendall Willkie Dordrecht
Last Updated: December 5, 2025
Wilson (Judith Basin) is a privately owned dam located in Montana, specifically in Judith Basin County.
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Summary
Also known as Surprise Creek Dam, it was designed by the USDA NRCS and serves the primary purpose of irrigation. Completed in 1952, this earth dam stands at a height of 28.6 feet with a hydraulic height of 24.5 feet, creating a storage capacity of 148 acre-feet for water from the Surprise Creek. The dam has a high hazard potential due to its location and condition assessment, but it was rated as satisfactory during the last inspection conducted in February 2021.
Although the Wilson dam has a moderate risk assessment rating, it remains regulated and inspected by the DNRC in Montana. It has a spillway width of 140 feet and is equipped with valve outlet gates for water control. The dam covers a drainage area of 15.6 square miles and has a maximum discharge capacity of 720 cubic feet per second. With a surface area of 12.3 acres and a normal storage capacity of 134 acre-feet, the Wilson (Judith Basin) dam plays a crucial role in sustaining agricultural activities through irrigation in the region. Despite its age, the dam continues to meet guidelines and is actively managed to ensure the safety of surrounding communities and water resources.
Year Completed |
1952 |
Dam Length |
680 |
Dam Height |
28.6 |
River Or Stream |
SURPRISE CREEK |
Primary Dam Type |
Earth |
Surface Area |
12.3 |
Hydraulic Height |
24.5 |
Drainage Area |
15.6 |
Nid Storage |
148 |
Structural Height |
28.6 |
Outlet Gates |
Valve |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
29 |
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.
Wilson (Judith Basin)