John Ballentine Dam Reservoir Report

Last Updated: December 5, 2025

John Ballentine Dam, located in Berkeley County, South Carolina, was completed in 1970 and stands at a height of 11 feet with a length of 720 feet.


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Summary

The primary purpose of this earth dam, with a buttress core type, is for recreation, offering a surface area of 28 acres and a storage capacity of 252 acre-feet. Situated on the TR-Wassamassa Swamp, this dam is under state regulation by the South Carolina Department of Health and Environmental Control (DHEC), ensuring regular inspections and enforcement of safety measures.

Despite its low hazard potential, John Ballentine Dam has been assessed to be in poor condition as of November 2017, highlighting the need for maintenance and potential upgrades. The dam's spillway type is uncontrolled, with no outlet gates or associated structures. Although the risk assessment categorizes it as moderate, with a DSAC (Dam Safety Action Classification) assigned date not specified, there is room for improvement in risk management measures to ensure the safety of the surrounding community and the environment. With its picturesque location and recreational opportunities, John Ballentine Dam holds potential for further enhancement and sustainable management in line with evolving climate and water resource conservation practices.

Year Completed

1970

Dam Length

720

Dam Height

11

River Or Stream

TR-WASSAMASSA SWAMP

Primary Dam Type

Earth

Surface Area

28

Nid Storage

252

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

11
       
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.