Flat Creek Dam Reservoir Report
Nearby: Shadehill Shadehill Dike No. 1
Last Updated: December 6, 2025
Flat Creek Dam, located in Perkins, South Dakota, was completed in 1934 by the Works Progress Administration (WPA) and stands at a height of 35 feet with a length of 1673 feet.
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Summary
The dam, primarily made of earth with a stone core, serves the purpose of water storage on the TR-GRAND river. With a normal storage capacity of 2300 acre-feet and a maximum storage of 4640 acre-feet, Flat Creek Dam plays a crucial role in managing water resources in the area.
The dam is regulated by the South Dakota Department of Agriculture and Natural Resources (DANR) and undergoes regular inspections, with the last inspection conducted in November 2018. Although the hazard potential is rated as low and the condition is not rated, a moderate risk assessment has been assigned. The dam features an uncontrolled spillway with a width of 50 feet and has a maximum discharge capacity of 14,482 cubic feet per second.
Flat Creek Dam, situated in a picturesque location with a drainage area of 21 square miles, is a vital infrastructure for water resource management in the region. With its historical significance and functional design, the dam continues to ensure water supply reliability and flood control measures for the community, while maintaining a moderate level of risk management.
Year Completed |
1934 |
Dam Length |
1673 |
Dam Height |
35 |
River Or Stream |
TR-GRAND |
Primary Dam Type |
Earth |
Hydraulic Height |
35 |
Drainage Area |
21 |
Nid Storage |
4640 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
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.
Flat Creek Dam