George Knapp Dam Reservoir Report

Last Updated: December 6, 2025

George Knapp Dam, located in Pennington, South Dakota, is a private-owned structure that serves as a crucial water resource for the area.


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Summary

Completed in 1955, this earth dam stands at a height of 15 feet and spans a length of 1060 feet, providing a storage capacity of 110 acre-feet. Situated on the TR-CHEYENNE river, the dam is regulated by the South Dakota Department of Environment and Natural Resources, ensuring proper inspection, enforcement, and permitting processes are in place.

Despite its low hazard potential, George Knapp Dam plays a significant role in flood control and water storage for the region. Managed by the Natural Resources Conservation Service, the dam supports a normal storage capacity of 48 acre-feet and a maximum discharge of 1800 cubic feet per second. While the condition of the dam is currently not rated, its strategic location and design contribute to its vital role in maintaining water quality and availability in the area.

As a key component of the local water infrastructure, George Knapp Dam contributes to the overall water management efforts in Pennington County. With its modest height and impressive storage capacity, the dam serves as a reliable resource for water supply, irrigation, and environmental conservation. As climate change continues to impact water resources, structures like George Knapp Dam play a crucial role in ensuring a sustainable and resilient water supply for the community.

Year Completed

1955

Dam Length

1060

Dam Height

15

River Or Stream

TR-CHEYENNE

Primary Dam Type

Earth

Hydraulic Height

15

Nid Storage

110

Hazard Potential

Low

Nid Height

15
       
Seasonal Comparison

Weather Forecast

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.