Gilbert No.2 Reservoir Report

Last Updated: December 6, 2025

Gilbert No.2 is a private dam located in Harding, South Dakota, along the TR-South Fork Grand River.


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Summary

Built in 1956, this earth dam stands at a height of 22 feet and has a storage capacity of 430 acre-feet. Despite its age, the dam's hazard potential is rated as low, and its condition has not been formally assessed.

Managed by the Natural Resources Conservation Service, Gilbert No.2 is not federally owned or funded. The dam is regulated by the South Dakota Department of Environment and Natural Resources, with state permitting, inspection, and enforcement in place. While the dam does not have a designated primary purpose, it serves as a vital water resource for the surrounding area, with a normal storage capacity of 175 acre-feet and a maximum discharge rate of 4200 cubic feet per second.

Although Gilbert No.2 has not been recently inspected, its emergency action plan status is unknown, and it has not been rated for condition assessment. Despite these uncertainties, the dam remains a crucial infrastructure for water management and climate resilience in the region, contributing to flood control and water supply for agricultural and environmental purposes.

Year Completed

1956

Dam Length

1050

Dam Height

22

River Or Stream

TR-SOUTH FORK GRAND RIVER

Primary Dam Type

Earth

Hydraulic Height

22

Nid Storage

430

Hazard Potential

Low

Nid Height

22
       
Seasonal Comparison

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Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.