Lester Sein Reservoir Report
Last Updated: December 6, 2025
Lester Sein is a privately owned earth dam located in Perkins, South Dakota, with a low hazard potential and a normal storage capacity of 60 acre-feet.
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Summary
Completed in 1949, this dam on the TRIB. SOUTH GRAND RIVER has a height of 24 feet and a length of 380 feet. While the dam is not currently rated for its condition, it is regulated by the South Dakota Department of Environment and Natural Resources (DENR) and undergoes regular inspections, permitting, and enforcement.
Managed by private owners, Lester Sein plays a vital role in water resource management in the region, providing flood control and water storage capabilities. The dam has a maximum discharge capacity of 200 cubic feet per second and a storage capacity of 86 acre-feet. Despite its older construction date, the dam continues to operate effectively and is essential for maintaining water quality and quantity in the area.
With its proximity to the St. Paul District of the US Army Corps of Engineers, Lester Sein contributes to the overall water infrastructure of the region. Even though it has not been assessed for its Emergency Action Plan (EAP) or condition, the dam remains a critical piece of infrastructure for water resource and climate enthusiasts interested in sustainable water management practices in South Dakota.
Year Completed |
1949 |
Dam Length |
380 |
Dam Height |
24 |
River Or Stream |
TRIB. SOUTH GRAND RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
24 |
Nid Storage |
86 |
Hazard Potential |
Low |
Nid Height |
24 |
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.
Lester Sein