Moos #1 Reservoir Report
Last Updated: December 6, 2025
Moos #1 is a privately owned irrigation dam located in Circle, Montana, along the TR-Horse Creek.
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Summary
Designed by the USDA NRCS and completed in 1943, this earth dam stands at 15 feet high and spans 300 feet in length, with a maximum storage capacity of 56 acre-feet. With a normal storage capacity of 35 acre-feet and a drainage area of 5.33 square miles, Moos #1 serves as a crucial water resource for agricultural purposes in the region.
Managed by the DNRC, Moos #1 has a low hazard potential and is currently not rated for its condition assessment. Despite not having a designated emergency action plan or updated inundation maps, this dam plays a vital role in water management and irrigation in McCone County, Montana. While it has not been inspected recently and lacks certain risk management measures, Moos #1 continues to support the local ecosystem and agricultural activities in the area.
As an important structure in the region, Moos #1 highlights the intersection of water resource management and climate resilience. While its condition assessment and risk management measures may need improvement, the dam's contribution to irrigation and water storage underscores the ongoing need for sustainable water management practices in the face of changing climate conditions. By addressing these challenges and ensuring proper maintenance and oversight, Moos #1 can continue to play a key role in supporting water security and agricultural sustainability in the region.
Year Completed |
1943 |
Dam Length |
300 |
Dam Height |
15 |
River Or Stream |
TR-HORSE CREEK |
Primary Dam Type |
Earth |
Surface Area |
7 |
Hydraulic Height |
12 |
Drainage Area |
5.33 |
Nid Storage |
56 |
Hazard Potential |
Low |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Redwater River At Circle Mt
|
1cfs |
Nelson Creek Near Van Norman Mt
|
33cfs |
Missouri River Near Wolf Point Mt
|
5020cfs |
Milk River At Nashua Mt
|
233cfs |
Poplar River Near Poplar Mt
|
28cfs |
Yellowstone River At Glendive Mt
|
6000cfs |
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.
Moos #1