Shadehill Reservoir Report
Last Updated: December 6, 2025
Shadehill is a federal-owned dam situated in Perkins, South Dakota, along the Grand River.
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Summary
Built in 1951 by the Bureau of Reclamation, this earth dam stands at a height of 145 feet and spans a length of 12,843 feet, with a storage capacity of 468,585 acre-feet. The primary purpose of Shadehill is flood risk reduction, although it also serves for irrigation and recreation purposes, covering a surface area of 9,900 acres and drawing from a drainage area of 3,120 square miles.
Managed by the Bureau of Reclamation, Shadehill is a significant structure in the region with a high hazard potential. Despite its critical role in flood risk reduction, the dam's condition assessment is currently listed as "Not Available," underscoring the importance of regular inspections and maintenance. While the dam has not been modified in recent years, its emergency action plan was last revised in 2017. With Dusty Johnson serving as the Congressional representative for the area, Shadehill remains a vital asset for water resource management in South Dakota, contributing to the region's water supply and recreational opportunities along its reservoir.
In the realm of water resource and climate enthusiasts, Shadehill's presence as a federal dam on the Grand River is a focal point for understanding the intersection of infrastructure, water management, and environmental stewardship. As a key component in flood risk reduction efforts, Shadehill not only safeguards communities and agricultural land but also provides a recreational outlet for residents and visitors alike. With its expansive storage capacity and strategic location, Shadehill stands as a testament to the ongoing need for effective water resource management in the face of changing climatic conditions and growing demands on water supplies.
Year Completed |
1951 |
Dam Length |
12843 |
Dam Height |
145 |
River Or Stream |
GRAND RIVER |
Primary Dam Type |
Earth |
Surface Area |
9900 |
Hydraulic Height |
114 |
Drainage Area |
3120 |
Nid Storage |
468585 |
Structural Height |
145 |
Hazard Potential |
High |
Nid Height |
145 |
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.
Shadehill