Nelson #2 Reservoir Report
Nearby: Nelson #1 Lyle Nelson #7
Last Updated: December 5, 2025
Nelson #2 is a privately owned earth dam located in McCone, Montana, along Anderson Creek.
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Summary
Built in 1960 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock, and small fish pond. With a height of 15 feet and a length of 1700 feet, Nelson #2 has a storage capacity of 83 acre-feet and a drainage area of 4.22 square miles.
Despite its low hazard potential, Nelson #2 is regulated and inspected by the Montana Department of Natural Resources and Conservation (DNRC). The dam has a spillway width of 80 feet and a maximum discharge capacity of 800 cubic feet per second. While its condition assessment is currently "not rated," Nelson #2 meets state permitting requirements and is subject to regular inspections to ensure its continued safety and functionality.
Nelson #2 is a crucial infrastructure for water resource management in the region, providing essential services for fire protection, livestock, and recreational use. As climate change continues to impact water resources, the maintenance and regulation of dams like Nelson #2 will be increasingly important to ensure the sustainable management of water supplies and the protection of communities downstream. With its strategic location and multiple functions, Nelson #2 embodies the intersection of water resource management and climate resilience in Montana.
Year Completed |
1960 |
Dam Length |
1700 |
Dam Height |
15 |
River Or Stream |
ANDERSON CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Drainage Area |
4.22 |
Nid Storage |
83 |
Hazard Potential |
Low |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Nelson Creek Near Van Norman Mt
|
33cfs |
Milk River At Nashua Mt
|
233cfs |
Missouri River Near Wolf Point Mt
|
5020cfs |
Redwater River At Circle Mt
|
4cfs |
Milk River At Tampico Mt
|
123cfs |
Poplar River Near Poplar Mt
|
28cfs |
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 #2