Johnstone Pasture Reservoir Report

Last Updated: December 7, 2025

Johnstone Pasture is a private dam located in Poplar, Montana, that serves multiple purposes including fire protection, stock, and small fish pond.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1950, this earth dam stands at a height of 18 feet and has a storage capacity of 51 acre-feet. Situated on the TR-Pasture Creek, this dam is regulated by the Montana Department of Natural Resources and Conservation (DNRC) and is inspected regularly to ensure its safety and functionality.

With a low hazard potential and a condition assessment of "Not Rated", Johnstone Pasture presents a reliable water resource for the surrounding area. The dam's primary purpose of fire protection highlights its importance in managing the risk of wildfires in the region. Additionally, its strategic location in Congressional District 00, Montana, under the representation of Greg Gianforte (R), underscores its significance in safeguarding the local environment and community.

Overall, Johnstone Pasture stands as a vital infrastructure for water resource management in Dawson County, Montana. Its role in providing water for livestock, fire protection, and recreational purposes makes it a valuable asset in the region. As efforts continue to monitor and maintain the dam, it remains a key player in enhancing water security and climate resilience in the area.

Year Completed

1950

Dam Length

150

Dam Height

18

River Or Stream

TR-PASTURE CREEK

Primary Dam Type

Earth

Hydraulic Height

18

Nid Storage

51

Hazard Potential

Low

Nid Height

18
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.