Lyman Number 6 Reservoir Report
Nearby: Lyman Number 4 Lyman Number 3
Last Updated: December 7, 2025
Lyman Number 6 is a privately owned earth dam located in Jones, South Dakota, with a primary purpose that is currently unspecified.
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Summary
The dam, completed in 1958, stands at a height of 27 feet and has a storage capacity of 39 acre-feet. Situated on the TR-Bad River, the dam serves to regulate water flow and provide flood protection to the surrounding area.
Managed by the Natural Resources Conservation Service, Lyman Number 6 is subject to state regulation, inspection, and enforcement to ensure its safety and efficacy. Despite having a low hazard potential and being in a not-rated condition assessment status, the dam's emergency action plan, risk assessment, and inundation maps preparedness remain unclear. With a maximum discharge capacity of 2835 cubic feet per second, the dam plays a crucial role in water resource management within the region.
Overall, Lyman Number 6 serves as a vital infrastructure for water resource enthusiasts and climate advocates in South Dakota. With its historical significance and ongoing regulatory oversight, the dam exemplifies the importance of maintaining and monitoring critical water infrastructure to ensure the safety and sustainability of water resources in the area.
Year Completed |
1958 |
Dam Length |
294 |
Dam Height |
27 |
River Or Stream |
TR-BAD RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
27 |
Nid Storage |
39 |
Hazard Potential |
Low |
Nid Height |
27 |
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.
Lyman Number 6