Engdahl #4 Reservoir Report
Last Updated: January 11, 2026
Engdahl #4 is a privately-owned earth dam located in Garfield County, Montana, along TR-HELL CREEK.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1950 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock watering, and creating a small fish pond. With a height of 25 feet and a length of 175 feet, Engdahl #4 has a storage capacity of 53 acre-feet and a maximum discharge rate of 500 cubic feet per second. The dam is regulated by the Montana Department of Natural Resources and Conservation (DNRC) and undergoes regular inspections, with a low hazard potential and a moderate risk assessment rating.
Despite its age, Engdahl #4 has not been rated for its condition and lacks an emergency action plan (EAP). The dam's spillway is uncontrolled with a width of 100 feet, and it has not been modified in recent years. The risk management measures for the dam are currently not specified, and it is not owned or funded by any federal agency. The surrounding area is designated as having a moderate risk level, with the dam being assigned a DSAC date and a risk assessment rating of 3. Overall, Engdahl #4 presents an interesting case study for water resource and climate enthusiasts, highlighting the importance of regular inspection and maintenance of aging infrastructure to ensure public safety and water resource management.
Year Completed |
1950 |
Dam Length |
175 |
Dam Height |
25 |
River Or Stream |
TR-HELL CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Drainage Area |
1.48 |
Nid Storage |
53 |
Hazard Potential |
Low |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Nelson Creek Near Van Norman Mt
|
33cfs |
Musselshell River At Mosby Mt
|
240cfs |
Flatwillow Creek Near Mosby Mt
|
17cfs |
Milk River At Nashua Mt
|
233cfs |
Milk River At Tampico Mt
|
123cfs |
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.
Engdahl #4