Nelson Dam No.1 Reservoir Report
Nearby: Deer Dam Paul's Irrigation Dam
Last Updated: December 13, 2025
Nelson Dam No.1, located in Harding, South Dakota, is a privately owned earth dam completed in 1974 by the Natural Resources Conservation Service.
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Summary
With a height of 25 feet and a length of 360 feet, this dam serves the primary purpose of water storage on the TR-Little M river. It has a maximum storage capacity of 80 acre-feet and a normal storage capacity of 10 acre-feet, with a low hazard potential rating.
Although the dam is not currently rated for its condition, it is regulated, permitted, inspected, and enforced by the South Dakota Department of Environment and Natural Resources. The dam has not undergone any modifications since its completion, and there is no emergency action plan prepared for it. Despite its low hazard potential, the dam plays a crucial role in managing water resources in the area and mitigating the impacts of climate change on the local ecosystem. For water resource and climate enthusiasts, Nelson Dam No.1 stands as a testament to the importance of responsible water management practices in the face of changing environmental conditions.
Year Completed |
1974 |
Dam Length |
360 |
Dam Height |
25 |
River Or Stream |
TR-LITTLE M |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Nid Storage |
80 |
Hazard Potential |
Low |
Nid Height |
25 |
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 Dam No.1