Harold Flatmoe Reservoir Report
Nearby: Tom Gabbert Floyd Hall
Last Updated: December 6, 2025
Harold Flatmoe is a privately-owned dam located in Perkins, South Dakota, along the YR Moreau River.
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Summary
Constructed in 1957, this earthen dam stands at a height of 16 feet and spans a length of 320 feet, with a storage capacity of 57 acre-feet. Despite its age, the dam has a low hazard potential and is currently rated as "Not Rated" in terms of its condition assessment.
Managed by the Natural Resources Conservation Service, Harold Flatmoe falls under the jurisdiction of the South Dakota Department of Environment and Natural Resources. It is regulated, permitted, inspected, and enforced by the state, ensuring compliance with safety standards. The dam's emergency action plan status and risk assessment details are not available, suggesting a need for further evaluation and documentation in the event of an emergency.
Given its significance in water resource management and climate resilience, Harold Flatmoe serves as a key infrastructure for flood control and water storage in the region. With its location on the YR Moreau River and close supervision by state authorities, this dam plays a crucial role in safeguarding communities and ecosystems against potential risks and hazards. Further monitoring and assessment of its condition and emergency response preparedness will be essential for ensuring its continued effectiveness and safety in the face of changing environmental conditions.
Year Completed |
1957 |
Dam Length |
320 |
Dam Height |
16 |
River Or Stream |
YR MOREAU RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
16 |
Nid Storage |
57 |
Hazard Potential |
Low |
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.
Harold Flatmoe