Nelson Dam Reservoir Report
Nearby: Latham Dam Homer Faeller
Last Updated: December 6, 2025
Nestled in Harding, South Dakota, the Nelson Dam stands as a vital structure on the TR MOREAU RIVER, serving as a water resource hub for the region.
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Summary
Built in 1956 by the Natural Resources Conservation Service, this private-owned Earth dam stands at 23 feet in height and spans 1050 feet in length. With a storage capacity of 350 acre-feet, it plays a crucial role in regulating water flow and ensuring water security for the surrounding areas.
Despite its age, the Nelson Dam has maintained a low hazard potential and is deemed to have a moderate risk level. The dam's uncontrolled spillway, with a width of 100 feet, allows for the safe release of excess water during peak flow periods. While it has not been inspected since 1999, the dam remains in a not rated condition, reflecting its sturdy construction and ability to withstand the test of time.
As a key component in South Dakota's water infrastructure, the Nelson Dam serves as a testament to the importance of maintaining and regulating water resources in the face of changing climate patterns. Its strategic location and design make it a critical asset in water management efforts, ensuring a reliable water supply for the region's agricultural, industrial, and residential needs.
Year Completed |
1956 |
Dam Length |
1050 |
Dam Height |
23 |
River Or Stream |
TR MOREAU RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
23 |
Drainage Area |
2 |
Nid Storage |
350 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
23 |
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