Yellow Water Main Dam Reservoir Report
Nearby: Yellow Water Dike J King #2
Last Updated: January 7, 2026
Yellow Water Main Dam, located on Yellow Water Creek in Petroleum County, Montana, was completed in 1938 for the primary purpose of irrigation.
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Summary
This rockfill dam stands at a height of 37 feet and has a storage capacity of 6695 acre-feet, with a normal storage level of 3835 acre-feet. The dam covers a surface area of 490 acres and serves a drainage area of 55 square miles, with a maximum discharge capacity of 3900 cubic feet per second.
Managed by the state agency DNRC, Yellow Water Main Dam is classified as a high hazard structure with a satisfactory condition assessment. The dam has a controlled spillway type and undergoes regular inspections with an inspection frequency of every 5 years. In case of emergencies, the dam's Emergency Action Plan is periodically reviewed and updated to meet safety guidelines. Despite its high risk assessment, the dam is crucial for providing irrigation water to the surrounding agricultural lands in Mosby, Montana.
Enthusiasts of water resources and climate will appreciate the historical significance and engineering marvel of Yellow Water Main Dam. Its strategic location on Yellow Water Creek supports the local agricultural community while also posing challenges in terms of potential hazards and risk management. As one of the key infrastructure projects in Montana, this dam serves as a vital water resource for sustaining the region's ecosystem and economy, highlighting the intricate balance between water management and environmental conservation in the face of changing climate conditions.
Year Completed |
1938 |
Dam Length |
1695 |
Dam Height |
37 |
River Or Stream |
YELLOW WATER CREEK |
Primary Dam Type |
Rockfill |
Surface Area |
490 |
Hydraulic Height |
37 |
Drainage Area |
55 |
Nid Storage |
6695 |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
37 |
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.
Yellow Water Main Dam