Twin Lakes Upper Dam Reservoir Report

Last Updated: December 5, 2025

Twin Lakes Upper Dam, located in Edgefield, South Carolina, was completed in 1948 for the primary purpose of recreation.


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Summary

This earth dam stands at a height of 17 feet and has a length of 270 feet, creating a reservoir with a storage capacity of 147 acre-feet. The dam is situated on the TR-Little Horse Creek and is owned privately, but is regulated by the South Carolina Department of Health and Environmental Control (DHEC).

The condition assessment of Twin Lakes Upper Dam is rated as poor, with a significant hazard potential. The last inspection took place in September 2020, and the dam is inspected every 3 years. Despite its condition, the dam continues to provide recreational opportunities for the local community, with a surface area of 11 acres. The dam's emergency action plan (EAP) was last revised in 2015, and further risk assessment and management measures are yet to be documented.

With its scenic location and historical significance, Twin Lakes Upper Dam serves as a vital water resource for the area while also posing potential risks due to its poor condition. Climate and water resource enthusiasts may find the dam's complex regulatory framework and maintenance challenges intriguing, as efforts to ensure the safety of the structure continue to be a priority for both the private owners and state authorities.

Year Completed

1948

Dam Length

270

Dam Height

17

River Or Stream

TR-LITTLE HORSE CREEK

Primary Dam Type

Earth

Surface Area

11

Nid Storage

147

Hazard Potential

Significant

Foundations

Soil

Nid Height

17
       
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.