Wallenstein Reservoir Report
Nearby: Ernest Wallstein Dam Scoria
Last Updated: December 5, 2025
Wallenstein is a privately owned irrigation dam located in Carter County, Montana, along the TR-Humbolt Creek.
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Summary
Built in 1945 by the USDA NRCS, this Earth dam stands at a height of 20 feet and spans 75 feet in length, with a storage capacity of 93 acre-feet. The dam serves the primary purpose of irrigation and is regulated by the Montana Department of Natural Resources and Conservation, ensuring that it meets state permitting, inspection, and enforcement standards.
With a low hazard potential and a condition assessment of "Not Rated," Wallenstein is a vital infrastructure for water resource management in the region. The dam has a spillway width of 50 feet and a maximum discharge of 500 cubic feet per second, providing important water supply and flood control benefits to the area. While the dam has not been modified in recent years and lacks certain emergency preparedness measures, its presence plays a crucial role in supporting agricultural activities and maintaining water security in the surrounding community.
Despite its age, Wallenstein continues to be a reliable asset for irrigation in the region, with a normal storage capacity of 48 acre-feet. Located in a remote area near Marmarth, North Dakota, this dam exemplifies the importance of sustainable water management practices and the need for ongoing monitoring and maintenance to ensure its continued functionality. For water resource and climate enthusiasts, Wallenstein serves as a reminder of the critical role that infrastructure plays in supporting agricultural livelihoods and environmental sustainability in arid regions like Montana.
Year Completed |
1945 |
Dam Length |
75 |
Dam Height |
20 |
River Or Stream |
TR-HUMBOLT CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Drainage Area |
0.67 |
Nid Storage |
93 |
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.
Wallenstein