Riedy Dam Reservoir Report
Nearby: Robinson Dam Allen Robinson
Last Updated: December 6, 2025
Riedy Dam, located in Perkins, South Dakota, is a privately owned structure that plays a crucial role in water resource management in the region.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1934, this earth dam stands at a height of 22 feet and has a storage capacity of 150 acre-feet, with a normal storage level of 54 acre-feet. The dam is situated on E. Thunder Hawk Creek and is regulated by the South Dakota Department of Agriculture and Natural Resources.
With a low hazard potential and a moderate risk assessment rating of 3, Riedy Dam is considered to be in relatively good condition, though it has not been recently assessed. Despite its age, the dam continues to serve its primary purpose of water storage and flood control effectively. The dam features an uncontrolled spillway with a width of 75 feet and a maximum discharge capacity of 2180 cubic feet per second.
Although Riedy Dam has not been inspected since December 1999, it remains a vital piece of infrastructure for the local community. Climate enthusiasts and water resource experts can appreciate the engineering and design of this historic dam, which continues to play a significant role in managing water resources in South Dakota.
Year Completed |
1934 |
Dam Length |
350 |
Dam Height |
22 |
River Or Stream |
E. THUNDER HAWK CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
22 |
Drainage Area |
6 |
Nid Storage |
150 |
Outlet Gates |
None |
Hazard Potential |
Low |
Nid Height |
22 |
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.
Riedy Dam