Nelson Dike B Reservoir Report
Nearby: Nelson Dike C Nelson Dike A
Last Updated: December 6, 2025
Nelson Dike B is a federal offstream storage reservoir located in Saco, Montana, serving as a vital irrigation source in the region.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1922 by the Bureau of Reclamation, this earth dam stands at 14 feet high and spans 1590 feet in length, with a storage capacity of 79,224 acre-feet. The reservoir covers a surface area of 4560 acres and receives diversions from the adjacent river, making it a key component of water management in the area.
Managed by the Bureau of Reclamation, Nelson Dike B has a high hazard potential and is categorized as a risk management priority. Despite its age, the dam's condition assessment is currently not available, prompting a need for further evaluation and maintenance. The reservoir plays a crucial role in supporting agricultural activities in Phillips County and contributes to the overall sustainability of water resources in the region. With its historical significance and ongoing importance for irrigation, Nelson Dike B remains a focal point for water resource and climate enthusiasts interested in the intersection of infrastructure and environmental conservation.
Year Completed |
1922 |
Dam Length |
1590 |
Dam Height |
14 |
River Or Stream |
OFFSTREAM STORAGE RESERVOIR RECEIVING DIVERSIONS F |
Primary Dam Type |
Earth |
Surface Area |
4560 |
Hydraulic Height |
9 |
Drainage Area |
35 |
Nid Storage |
79224 |
Structural Height |
14 |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
14 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Nelson Dike B