Green Coulee Dam Reservoir Report
Nearby: Burgess #1 (Garfield) Burgess #2
Last Updated: December 5, 2025
Green Coulee Dam, located in Garfield County, Montana, was constructed in 1960 by the USDA NRCS for the primary purposes of fire protection, stock water supply, and small fish pond creation.
°F
°F
mph
Wind
%
Humidity
Summary
This earth dam stands at a height of 20 feet and stretches 200 feet in length, with a storage capacity of 78 acre-feet. Situated on TR-Flat Creek, the dam is regulated by the Montana Department of Natural Resources and Conservation (DNRC) and is inspected, permitted, and enforced by the state.
With a low hazard potential and a moderate risk assessment rating, Green Coulee Dam serves as a vital infrastructure for water resource management in the region. The dam's uncontrolled spillway, with a width of 50 feet, can handle a maximum discharge of 250 cubic feet per second. Although the dam's condition assessment is currently not rated, it meets state regulatory requirements and demonstrates a commitment to ensuring public safety and environmental protection. As a private-owned structure, Green Coulee Dam plays a crucial role in sustaining the local ecosystem and providing essential water resources for various purposes.
Year Completed |
1960 |
Dam Length |
200 |
Dam Height |
20 |
River Or Stream |
TR-FLAT CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Drainage Area |
3.91 |
Nid Storage |
78 |
Hazard Potential |
Low |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Nelson Creek Near Van Norman Mt
|
33cfs |
Redwater River At Circle Mt
|
4cfs |
Milk River At Nashua Mt
|
233cfs |
Missouri River Near Wolf Point Mt
|
5020cfs |
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.
Green Coulee Dam