Nelson Dam Reservoir Report
Nearby: Sd Noname 238 Sd Noname 242
Last Updated: December 6, 2025
Nelson Dam, located in Haakon, South Dakota, was completed in 1976 and stands at a height of 30 feet, with a storage capacity of 144 acre-feet.
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Summary
This earth dam on Witcher Hole Creek is primarily owned by a private entity and falls under the regulatory jurisdiction of the South Dakota Department of Environment and Natural Resources (DENR). The dam is classified as having a low hazard potential and a moderate risk assessment rating.
Despite being an earth dam with uncontrolled spillways, Nelson Dam has not been rated for its overall condition and lacks an Emergency Action Plan (EAP). While the dam has not been modified over the years and has no associated structures or outlet gates, it does have the capacity to discharge up to 540 cubic feet per second. With its proximity to residential and agricultural areas, it is crucial for stakeholders to stay informed about potential risks and management measures related to Nelson Dam to ensure public safety and water resource protection in the region.
Year Completed |
1976 |
Dam Length |
400 |
Dam Height |
30 |
River Or Stream |
TR WITCHER HOLE CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
30 |
Nid Storage |
144 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
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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