Koss #3 Reservoir Report
Nearby: Stratton Reservoir R Ereaux #1
Last Updated: December 6, 2025
Koss #3, also known as Stockade, is a privately owned earth dam located in Phillips County, Montana.
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Summary
Designed by the USDA NRCS and completed in 1945, this irrigation dam has a height of 20 feet and a length of 350 feet, with a storage capacity of 150 acre-feet. Situated on TR-SECOND CREEK, this dam serves the primary purpose of irrigation, supporting agriculture in the region.
Despite being classified as a low hazard potential structure with a condition assessment of "Not Rated," Koss #3 is regulated, permitted, inspected, and enforced by the DNRC in Montana. With a spillway width of 50 feet and a maximum discharge of 250 cfs, this dam plays a crucial role in water resource management in the area. The dam's location in a rural setting further emphasizes its importance in sustaining agricultural activities and supporting the local ecosystem.
As an integral part of the irrigation infrastructure in Phillips County, Montana, Koss #3 exemplifies the collaboration between private owners and government agencies in managing water resources effectively. With a focus on maintaining safety and functionality, this dam stands as a testament to the vital role of small-scale irrigation structures in sustaining agriculture and mitigating the impacts of climate change on water availability in the region.
Year Completed |
1945 |
Dam Length |
350 |
Dam Height |
20 |
River Or Stream |
TR-SECOND CREEK |
Primary Dam Type |
Earth |
Surface Area |
19 |
Hydraulic Height |
20 |
Drainage Area |
3.02 |
Nid Storage |
150 |
Hazard Potential |
Low |
Nid Height |
20 |
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.
Koss #3