John Isaac Reservoir Report
Nearby: Sorum Dam Glenn Wishard
Last Updated: December 6, 2025
John Isaac is a private earth dam located in Perkins, South Dakota, along the TR Moreau River.
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Summary
Built in 1951 by the Natural Resources Conservation Service, this dam stands at a height of 20 feet and has a length of 400 feet. With a storage capacity of 72 acre-feet, John Isaac serves as a vital water resource for the surrounding area, providing a maximum discharge of 500 cubic feet per second.
Despite its age, John Isaac has a low hazard potential and is currently rated as "Not Rated" in terms of its condition assessment. While lacking specific inspection dates, the dam is regulated, permitted, inspected, and enforced by the South Dakota Department of Environment and Natural Resources. The dam's emergency action plan status, risk assessment, and management measures are currently not available, indicating a need for further evaluation and preparedness in response to potential climate-related challenges.
Overall, John Isaac plays a crucial role in water management in South Dakota, highlighting the importance of monitoring and maintaining aging infrastructure to ensure the safety and sustainability of water resources in the face of climate change impacts. As climate enthusiasts, it is imperative to stay informed about the status of dams like John Isaac to advocate for sustainable water resource management practices and adaptation strategies in the changing climate landscape.
Year Completed |
1951 |
Dam Length |
400 |
Dam Height |
20 |
River Or Stream |
TR MOREAU RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Nid Storage |
72 |
Hazard Potential |
Low |
Nid Height |
20 |
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.
John Isaac