Mckay Creek Reservoir Report
Nearby: Beaver Pond Gravely
Last Updated: December 5, 2025
Mckay Creek, also known as Size Six Foot, is a privately owned irrigation dam located in Avon, Montana.
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Summary
Constructed in 1955 by the USDA NRCS, this earth dam stands at a height of 33 feet and has a length of 800 feet, providing a storage capacity of 156 acre-feet for irrigation purposes. Situated on TR-Sixmile Creek, the dam has a surface area of 20.5 acres and serves a drainage area of 0.34 square miles.
Managed by the Montana Department of Natural Resources and Conservation (DNRC), Mckay Creek Dam has a high hazard potential due to its critical role in supplying water for agricultural activities in the region. The dam has a maximum discharge capacity of 60 cubic feet per second and features a spillway width of 38 feet to manage excess water flow. Although the condition of the dam is currently not rated, regular inspections are carried out every 5 years to ensure its safety and integrity.
With its strategic location and vital contribution to the local irrigation infrastructure, Mckay Creek Dam plays a crucial role in water resource management in Powell County, Montana. As a key structure designed for irrigation purposes, this privately owned dam continues to support agricultural activities in the area, highlighting the importance of sustainable water management practices in the face of changing climate conditions.
Year Completed |
1955 |
Dam Length |
800 |
Dam Height |
33 |
River Or Stream |
TR-SIXMILE CREEK |
Primary Dam Type |
Earth |
Surface Area |
20.5 |
Hydraulic Height |
33 |
Drainage Area |
0.34 |
Nid Storage |
156 |
Hazard Potential |
High |
Nid Height |
33 |
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.
Mckay Creek
Gallagher Creek