Louis Bonhorst Number 4 Reservoir Report
Last Updated: December 14, 2025
Louis Bonhorst Number 4 is a privately owned earth dam located in Stanley County, South Dakota, along the tributary Plum Creek.
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Summary
Built in 1961 by the Natural Resources Conservation Service, this dam stands at a height of 35 feet and has a storage capacity of 32 acre-feet. With a low hazard potential and a condition assessment that is not rated, this structure is regulated by the South Dakota Department of Environment and Natural Resources, which conducts inspections, permitting, and enforcement activities to ensure its safety and compliance.
Although the dam's primary purpose is unspecified, it serves as a vital resource for water management and flood control in the region. With a maximum discharge capacity of 2700 cubic feet per second, this structure plays a crucial role in mitigating the risk of flooding and protecting the surrounding communities. Despite not having an Emergency Action Plan in place, Louis Bonhorst Number 4 continues to be a key component of the local water infrastructure, safeguarding the area from potential water-related hazards.
As an essential part of the water resource system in South Dakota, Louis Bonhorst Number 4 contributes to the overall resilience and sustainability of the region. With its historical significance dating back to the early 1960s, this earth dam stands as a testament to the importance of proper water management and infrastructure development in ensuring the well-being of both the environment and the local population. As climate change continues to pose challenges to water resources, structures like Louis Bonhorst Number 4 will play a crucial role in adapting to the changing conditions and safeguarding the community against potential risks.
Year Completed |
1961 |
Dam Length |
380 |
Dam Height |
35 |
River Or Stream |
TRIB. PLUM CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
35 |
Nid Storage |
32 |
Hazard Potential |
Low |
Nid Height |
35 |
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.
Louis Bonhorst Number 4