Ring Thunder Reservoir Report
Nearby: Krogman No.6 Krogman No.5
Last Updated: December 8, 2025
Ring Thunder is a federal-owned recreational dam located in South Dakota, specifically in Todd County.
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Summary
Built in 1974 by the Bureau of Indian Affairs, this earth dam stands at a structural height of 30 feet and spans 900 feet in length. With a storage capacity of 300 acre-feet, the primary purpose of Ring Thunder is for recreation, offering visitors the opportunity to enjoy the surrounding Little Oak Creek-Tr stream.
Despite its recreational appeal, Ring Thunder poses a high hazard potential, with a very high risk assessment rating. However, the condition assessment is currently marked as "Not Available," and the last inspection was conducted in August 2012 with a frequency of every 5 years. It is crucial that risk management measures are put in place to address the potential risks associated with this dam, given its location and the high hazard potential it presents.
In the event of an emergency, it is unclear whether an Emergency Action Plan (EAP) has been prepared for Ring Thunder, as the status is listed as "Not Available." It is essential for the Bureau of Indian Affairs to update and ensure that the EAP meets established guidelines to protect surrounding communities in the event of a dam failure. With proper risk assessment and management measures in place, Ring Thunder can continue to provide recreational opportunities while ensuring the safety of those who visit and live in the area.
Year Completed |
1974 |
Dam Length |
900 |
River Or Stream |
LITTLE OAK CREEK -TR |
Primary Dam Type |
Earth |
Nid Storage |
300 |
Structural Height |
30 |
Hazard Potential |
High |
Nid Height |
30 |
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.
Ring Thunder