Hansen Lake Dam Reservoir Report
Nearby: Porta Reservoir No. 2 Andy Capp
Last Updated: December 14, 2025
Hansen Lake Dam, also known as Portra Reservoir #1, is a private-owned earth dam located in Medicine Lake, Montana.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1946, this dam serves multiple purposes including fire protection, stock, and small fish pond. With a structure height of 12.3 feet and a hydraulic height of 8 feet, the dam has a storage capacity of 753 acre-feet, with a normal storage level of 250 acre-feet.
Situated on TR-SAND CR river, Hansen Lake Dam is regulated by the Montana Department of Natural Resources and Conservation (DNRC). Despite being classified as having a low hazard potential, the dam's condition is currently not rated. While the dam has not undergone a recent inspection, it is subject to state regulation, inspection, and enforcement, ensuring its safety and compliance with standards. The dam's location in the Roosevelt County of Montana adds to its significance as a vital water resource for the region.
Water resource and climate enthusiasts will find Hansen Lake Dam an interesting subject for study and monitoring. Its historical significance, multi-purpose functionality, and state-regulated status make it a valuable asset for water management in the region. As climate change continues to impact water resources, the condition and safety of dams like Hansen Lake Dam become increasingly important for ensuring water security and resilience in the face of changing environmental conditions.
Year Completed |
1946 |
Dam Length |
200 |
Dam Height |
12.3 |
River Or Stream |
TR-SAND CR |
Primary Dam Type |
Earth |
Hydraulic Height |
8 |
Nid Storage |
753 |
Hazard Potential |
Low |
Nid Height |
12 |
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.
Hansen Lake Dam