Demontigny Reservoir Report
Nearby: Pr-54 Retention Dam French Fry #1
Last Updated: December 6, 2025
Demontigny is a privately owned irrigation dam located in Whitewater, Montana, along the TR-Whitewater Creek.
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Summary
Built in 1954 by the USDA NRCS, this earth dam stands at 20 feet high and spans 200 feet in length, with a storage capacity of 82 acre-feet. Despite being regulated by the Montana Department of Natural Resources and Conservation, Demontigny has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment.
This structure plays a crucial role in providing irrigation water for agricultural purposes in the region, with a normal storage capacity of 42 acre-feet. The dam's maximum discharge capacity is 150 cubic feet per second, ensuring efficient water distribution for the 3.25 square mile drainage area it serves. Although the dam has not undergone recent inspections or assessments, its low hazard potential indicates a stable and safe operation for the surrounding area.
With its strategic location and significant contribution to local water resource management, Demontigny serves as a vital infrastructure for sustaining agricultural activities in Phillips County, Montana. The dam's design and construction by the USDA NRCS reflect a commitment to water conservation and land stewardship, highlighting the importance of maintaining and monitoring such structures to ensure their continued effectiveness in water supply management. As climate enthusiasts and water resource advocates, the data on Demontigny offers valuable insights into the intersection of infrastructure, environmental regulation, and sustainable water use in the region.
Year Completed |
1954 |
Dam Length |
200 |
Dam Height |
20 |
River Or Stream |
TR-WHITEWATER CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Drainage Area |
3.25 |
Nid Storage |
82 |
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.
Demontigny