Simpson Bros. Reservoir Report
Nearby: White Hill Dam Mollman Dam
Last Updated: December 6, 2025
Simpson Bros.
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Summary
is a private dam located in Perkins, South Dakota, along the TR-SOUTH GRAND RIVER. Built in 1972, this earth dam stands at 19 feet high and spans 450 feet in length, providing a storage capacity of 60 acre-feet. Managed by the Natural Resources Conservation Service, Simpson Bros. is regulated by the South Dakota Department of Environment and Natural Resources, ensuring that it meets state permitting, inspection, and enforcement requirements.
With a low hazard potential and a condition assessment that is currently not rated, Simpson Bros. serves as a crucial part of water resource management in the area. Although the dam has not been inspected recently, it continues to play a vital role in flood control and water storage along the river. The dam's emergency action plan status, inundation maps, and risk assessment details are currently unavailable, highlighting the need for updated safety measures and risk management strategies.
As climate change continues to impact water resources and weather patterns, the significance of structures like Simpson Bros. in maintaining water security and mitigating risks becomes increasingly apparent. With its strategic location and operational history, this private dam stands as a testament to the importance of sustainable water management practices in the face of evolving environmental challenges.
Year Completed |
1972 |
Dam Length |
450 |
Dam Height |
19 |
River Or Stream |
TR-SOUTH GRAND RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
19 |
Nid Storage |
60 |
Hazard Potential |
Low |
Nid Height |
19 |
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.
Simpson Bros.