Hanson Creek Dam Reservoir Report
Nearby: Pike Creek Dam East Fork Dam
Last Updated: December 5, 2025
Hanson Creek Dam, located in Lewistown, Montana, was completed in 1974 and serves multiple purposes including flood risk reduction and recreation.
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Summary
The dam, owned by the local government and designed by USDA NRCS, stands at a height of 61 feet with a hydraulic height of 62 feet and a structural height of 72 feet. It has a storage capacity of 860 acre-feet and a surface area of 32 acres, making it a significant water resource for the area.
With a high hazard potential and a satisfactory condition assessment, the dam is regulated and inspected by the Montana Department of Natural Resources Conservation (DNRC). The spillway type is uncontrolled with a width of 400 feet, and the maximum discharge capacity is 14,500 cubic feet per second. The dam is situated on Hanson Creek and plays a crucial role in managing water resources in the region.
Water resource and climate enthusiasts will find Hanson Creek Dam an interesting site to explore due to its unique design and purpose. The dam's moderate risk assessment rating indicates the importance of ongoing monitoring and maintenance to ensure its continued reliability in managing flood risks and providing recreational opportunities for the community. With its picturesque location and significant impact on the local water system, Hanson Creek Dam is a noteworthy example of sustainable water resource management in Montana.
Year Completed |
1974 |
Dam Length |
759 |
Dam Height |
61 |
River Or Stream |
HANSON CREEK |
Primary Dam Type |
Earth |
Surface Area |
32 |
Hydraulic Height |
62 |
Drainage Area |
9.85 |
Nid Storage |
860 |
Structural Height |
72 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
72 |
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.
Hanson Creek Dam