South Fork Impoundment Reservoir Report
Nearby: Pasture 6en Du Swsw Lester Sein
Last Updated: December 6, 2025
South Fork Impoundment, located in Shadehill, South Dakota, is a Federal-owned structure managed by the USDA Forest Service.
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Summary
Completed in 1992, this Earth-type dam stands at a height of 16 feet and serves primarily as a Fish and Wildlife Pond. With a storage capacity of 148 acre-feet and a surface area of 21 acres, the dam plays a crucial role in maintaining water resources for recreational activities and wildlife habitat in the area.
Despite its low hazard potential and moderate risk assessment, South Fork Impoundment has not been rated for its condition. While it lacks a formal Emergency Action Plan (EAP) and inundation maps, the dam is inspected every 10 years by the Forest Service to ensure its safety and functionality. The spillway, with a width of 170 feet, serves as an uncontrolled outlet for excess water, highlighting the importance of proper water management in this region.
With its location in the Perkins County along the North Fork, South Fork, and Grand Rivers, South Fork Impoundment stands as a vital resource for water conservation and recreational activities. As climate enthusiasts and water resource advocates, it is essential to monitor and support the maintenance of this dam to preserve its ecological significance and ensure the sustainable use of water in the area.
Year Completed |
1992 |
Dam Length |
675 |
Dam Height |
16 |
River Or Stream |
N.FORK-S.FORK-GRAND RIVER |
Primary Dam Type |
Earth |
Surface Area |
21 |
Hydraulic Height |
12 |
Drainage Area |
6 |
Nid Storage |
148 |
Structural Height |
12 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
16 |
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.
South Fork Impoundment