Hillside (Lake) Reservoir Report
Nearby: Ninepipe Maughan Dam
Last Updated: December 5, 2025
Hillside (Lake) is a significant water resource located in Lake, Montana, with a storage capacity of 95 acre-feet and a dam height of 30 feet.
°F
°F
mph
Wind
%
Humidity
Summary
The dam was completed in 1940 under the supervision of the DOI BIA. Despite not being state-regulated, Hillside (Lake) has a significant hazard potential, highlighting the importance of proper monitoring and maintenance to ensure its structural integrity.
Although specific details about the dam's purpose, design, and construction are not available, its location within the Seattle District suggests its importance for water management in the region. With a lack of recent inspection data and condition assessment, it is crucial for water resource and climate enthusiasts to advocate for comprehensive monitoring and emergency preparedness measures to mitigate potential risks associated with the dam. Furthermore, engaging with federal agencies and local stakeholders to ensure the dam's safety and compliance with guidelines is essential for the long-term sustainability of Hillside (Lake) as a vital water resource.
As a site with limited information available, Hillside (Lake) presents an opportunity for further research and engagement by water resource and climate enthusiasts. By advocating for regular inspections, emergency preparedness measures, and risk management strategies, stakeholders can contribute to the preservation and sustainable use of this important water resource in Montana. Additionally, collaboration with federal agencies and local communities can help ensure the safety and integrity of Hillside (Lake) for current and future generations.
Year Completed |
1940 |
Dam Height |
30 |
Nid Storage |
95 |
Hazard Potential |
Significant |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South Crow Creek Near Ronan Mt
|
9cfs |
Mission Cr Ab Reservoir Nr St Ignatius Mt
|
27cfs |
Flathead River At Perma Mt
|
8540cfs |
Flathead River Near Polson Mt
|
8210cfs |
South Fork Jocko River Near Arlee Mt
|
83cfs |
Clark Fork Near Plains Mt
|
11300cfs |
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.
Hillside (Lake)