Herman Number 20 Reservoir Report
Nearby: Fho Ranch No.1 Herman Number 17
Last Updated: December 13, 2025
Herman Number 20 is a privately owned earth dam located in Jones, South Dakota, with a low hazard potential and a height of 28 feet.
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Summary
Constructed in 1960 by the Natural Resources Conservation Service, this dam serves the primary purpose of water resource management on the TR-Bad River. With a storage capacity of 27 acre-feet and a maximum discharge of 756 cubic feet per second, Herman Number 20 plays a crucial role in regulating water flow in the region.
Owned and regulated by the state of South Dakota, Herman Number 20 is subject to state jurisdiction, permitting, inspection, and enforcement by the Department of Environment and Natural Resources (DENR). Despite being in operation for over six decades, the dam's condition assessment is currently marked as "Not Rated," indicating a need for further evaluation. Emergency action plans and risk management measures for the dam are currently not documented, highlighting potential areas for improvement in ensuring the safety and integrity of this essential water resource infrastructure.
Situated within the St. Paul District of the US Army Corps of Engineers, Herman Number 20 stands as a vital component of the region's water resource system. As climate change continues to impact water availability and quality, the proper maintenance and monitoring of dams like Herman Number 20 become increasingly crucial for sustainable water management in South Dakota.
Year Completed |
1960 |
Dam Length |
542 |
Dam Height |
28 |
River Or Stream |
TR-BAD RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
28 |
Nid Storage |
27 |
Hazard Potential |
Low |
Nid Height |
28 |
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.
Herman Number 20