Manchester Reservoir Report
Nearby: Payton Place Sunny Bueno
Last Updated: December 5, 2025
Located in Cascade County, Montana, Manchester is a privately owned water resource regulated by the Montana Department of Natural Resources and Conservation (DNRC).
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Summary
The dam on the Sun River has a significant hazard potential and a maximum storage capacity of 150 acre-feet, with a normal storage of 100 acre-feet. Despite not being rated for its condition, Manchester meets state jurisdiction and regulatory requirements, with inspection, enforcement, and permitting all in place.
With a hydraulic height of 6 feet and a dam height of 8 feet, Manchester serves a primary purpose classified as "Other," indicating its multifaceted role in water resource management. Although the dam's completion year is unspecified, its location in Congressional District 00 of Montana underscores its importance in the region's water infrastructure. The presence of emergency action plans and risk management measures, however, is not explicitly stated, raising questions about preparedness for potential hazards.
As a water resource and climate enthusiast in Manchester, there is an opportunity to delve deeper into the dam's design and operational aspects, such as spillway types, outlet gates, and potential modifications over the years. Understanding the risk assessment and emergency response protocols for Manchester could provide valuable insights into the resilience of the region's water infrastructure in the face of changing climate patterns. Further exploration of Manchester's role in supporting irrigation, flood control, and other water-related activities can shed light on its significance in sustaining local ecosystems and communities in Montana.
Dam Height |
8 |
River Or Stream |
TR - SUN RIVER |
Hydraulic Height |
6 |
Nid Storage |
150 |
Hazard Potential |
Significant |
Nid Height |
8 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Muddy Creek At Vaughn Mt
|
86cfs |
Sun River Near Vaughn Mt
|
2680cfs |
Missouri River Near Ulm Mt
|
3160cfs |
Lake Creek Near Power Mt
|
30cfs |
Missouri River Near Great Falls Mt
|
3530cfs |
Sun River At Simms Mt
|
1620cfs |
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.
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