Lyman Number 4 Reservoir Report
Nearby: Lyman Number 3 Lyman Number 6
Last Updated: December 7, 2025
Lyman Number 4 is a privately owned earth dam located in Jones County, South Dakota, near the city of Bone.
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Summary
Built in 1957 by the Natural Resources Conservation Service, this dam stands at a height of 27 feet and has a storage capacity of 54 acre-feet, with a normal storage level of 33 acre-feet. It is situated on the TR-BAD River and falls under the regulatory jurisdiction of the South Dakota Department of Environment and Natural Resources.
The dam has a low hazard potential and is currently rated as "Not Rated" in terms of its condition assessment. While specific details about its inspection frequency, emergency action plan, and risk management measures are not provided in the data, it is clear that the dam plays a crucial role in water resource management and flood control in the area. With a maximum discharge capacity of 504 cubic feet per second, Lyman Number 4 serves as a key infrastructure for regulating water flow in the region.
Although the dam's associated structures, inspection dates, and emergency preparedness information are not included in the dataset, its significance in safeguarding the local community against potential water-related risks cannot be understated. As a vital component of the St. Paul District of the US Army Corps of Engineers, Lyman Number 4 highlights the importance of effective water resource management and climate resiliency efforts in the face of changing environmental conditions.
Year Completed |
1957 |
Dam Length |
339 |
Dam Height |
27 |
River Or Stream |
TR-BAD RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
27 |
Nid Storage |
54 |
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 4