Seven-Up Detention Dam Reservoir Report
Nearby: Lazy J-D #4 Gull Wing Detention Dam
Last Updated: December 5, 2025
Seven-Up Detention Dam, located in Phillips County, Montana, serves multiple purposes, including fire protection, stock maintenance, and providing a habitat for small fish.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1967 by the Bureau of Land Management, this gravity dam stands at a height of 24 feet and has a hydraulic height of 20 feet. With a storage capacity of 162.6 acre-feet, the dam covers a drainage area of 2.5 square miles and has a surface area of 27 acres.
Managed by the Bureau of Land Management, Seven-Up Detention Dam is classified as having a low hazard potential and a fair condition assessment. The dam features an uncontrolled spillway with a width of 2 feet and has a moderate risk assessment rating. Despite its age, the dam is regularly inspected every five years to ensure its structural integrity and safety. The surrounding area is monitored for any potential risks, and emergency preparedness measures are in place to mitigate any potential hazards.
As an essential water resource for the region, Seven-Up Detention Dam plays a crucial role in water conservation and management. With its strategic location on Seven Mile Creek near the Missouri River, the dam not only provides valuable water storage but also contributes to the local ecosystem. Climate and water resource enthusiasts can appreciate the engineering marvel of this dam and the efforts taken to ensure its continued functionality for both human and environmental purposes.
Year Completed |
1967 |
Dam Length |
1170 |
River Or Stream |
SEVEN MILE CK./MISSOURI RIVER |
Primary Dam Type |
Gravity |
Surface Area |
27 |
Hydraulic Height |
20 |
Drainage Area |
2.5 |
Nid Storage |
162.6 |
Structural Height |
24 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
24 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Missouri River Near Landusky Mt
|
9100cfs |
Peoples Creek Near Hays Mt
|
4cfs |
Milk River Near Dodson Mt
|
68cfs |
Milk River At Malta Mt
|
0cfs |
Milk River Near Harlem Mt
|
69cfs |
Judith River Nr Mouth
|
368cfs |
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.
Seven-Up Detention Dam