Loiseau Dam Reservoir Report
Nearby: Jacobs Dam Warren Jackson Dam
Last Updated: December 13, 2025
Loiseau Dam, located in Moody County, South Dakota, was completed in 1993 and stands at a height of 19 feet with a length of 356 feet.
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Summary
This earth-type dam on a tributary of the Big Sioux River has a storage capacity of 69 acre-feet and a maximum discharge of 450 cubic feet per second. Despite being privately owned, the dam is regulated by the South Dakota Department of Environment and Natural Resources (DENR) and is subject to state permitting, inspection, and enforcement.
With a low hazard potential and a condition assessment of "Not Rated," Loiseau Dam serves as a crucial infrastructure for water resource management in the region. While its Emergency Action Plan status and risk assessment remain unspecified, the dam's structure, with a spillway width of 84 feet, ensures the safety of surrounding communities in the event of a flood or emergency situation. As water resource and climate enthusiasts, understanding the details and significance of dams like Loiseau is essential for promoting sustainable water management practices and mitigating potential risks associated with aging infrastructure.
Year Completed |
1993 |
Dam Length |
356 |
Dam Height |
19 |
River Or Stream |
TRIB. BIG SIOUX RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
19 |
Drainage Area |
1 |
Nid Storage |
69 |
Hazard Potential |
Low |
Nid Height |
19 |
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.
Loiseau Dam