Hett No.2 Reservoir Report
Nearby: Hett No.1 Gilbert No.2
Last Updated: December 6, 2025
Hett No.2 is a privately owned earth dam located in Harding, South Dakota, along the TR-SOUTH FORK GRAND RIVER.
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Summary
Built in 1949 by the Natural Resources Conservation Service, this dam stands at a height of 19 feet and has a length of 395 feet, providing a storage capacity of 142 acre-feet. While the dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is regulated by the South Dakota Department of Environment and Natural Resources, with regular inspections and enforcement measures in place to ensure its safety and compliance.
Despite its age, Hett No.2 continues to serve its primary purpose of water storage and management effectively, with a maximum discharge capacity of 420 cubic feet per second. The dam's normal storage capacity is 75 acre-feet, and it plays a crucial role in managing water resources in the region. With its strategic location and design, Hett No.2 remains a vital infrastructure for mitigating flood risks, providing irrigation water, and supporting the overall ecological balance of the area. As a key component of the local water resource infrastructure, this dam exemplifies the importance of sustainable water management practices in the face of changing climate conditions.
Year Completed |
1949 |
Dam Length |
395 |
Dam Height |
19 |
River Or Stream |
TR-SOUTH FORK GRAND RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
19 |
Nid Storage |
142 |
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.
Hett No.2