Hess Reservoir Report

Last Updated: December 5, 2025

Hess is a privately owned water resource located in Fergus County, Montana, with a primary purpose of serving as a fire protection, stock, or small fish pond.


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Summary

Built in 1930, the earth dam stands at 20 feet high and has a storage capacity of 51 acre-feet, with a normal storage level of 26 acre-feet. The dam is situated on the TR-Missouri River and falls under the jurisdiction of the Montana Department of Natural Resources and Conservation (DNRC).

Although Hess has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is subject to state regulation, permitting, inspection, and enforcement. The dam has a maximum discharge capacity of 1200 cubic feet per second and a length of 350 feet. Despite lacking detailed data on surface area, drainage area, spillway type, and outlet gates, Hess remains a crucial water resource for fire protection and livestock management in the region. With its historical significance and role in supporting local ecosystems, Hess contributes to the sustainable management of water resources in Montana.

As water resource and climate enthusiasts, the Hess dam presents an intriguing case study in the resilience and management of small-scale water infrastructure. With its modest size and multi-purpose functionality, Hess showcases the importance of maintaining and monitoring dams for both human and environmental needs. By staying informed about the regulatory oversight, condition assessment, and emergency preparedness measures associated with Hess, enthusiasts can gain valuable insights into the complexities of water resource management in the face of changing climate conditions. As a key player in the local water landscape, Hess serves as a reminder of the interconnectedness between water resources, climate dynamics, and sustainable development practices.

Year Completed

1930

Dam Length

350

Dam Height

20

River Or Stream

TR-MISSOURI RIVER

Primary Dam Type

Earth

Hydraulic Height

20

Nid Storage

51

Hazard Potential

Low

Nid Height

20
       
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.