Basil Mack Dam Reservoir Report
Last Updated: December 7, 2025
Basil Mack Dam, located in Lexington, South Carolina, along the Sandy Run River, was completed in 1999 for the primary purpose of flood risk reduction.
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Summary
This privately owned earth dam stands at 13 feet in height and spans 230 feet in length, with a maximum storage capacity of 60 acre-feet. The dam's condition was assessed as fair during its last inspection in April 2017, with a low hazard potential and a moderate risk assessment rating of 3.
Despite its relatively modest size, Basil Mack Dam plays a crucial role in managing flood risks in the area and supporting fish and wildlife habitats. The dam's stone core and soil foundation provide structural integrity, while its uncontrolled spillway ensures excess water can safely flow downstream. The dam is regulated and inspected by the South Carolina Department of Health and Environmental Control (DHEC), with permits and enforcement mechanisms in place to maintain its safety and functionality.
With its strategic location and vital role in flood control, Basil Mack Dam serves as a key infrastructure asset in the Savannah District. The dam's moderate risk assessment underscores the importance of ongoing monitoring and maintenance to safeguard its effectiveness in mitigating flood risks and supporting the surrounding ecosystem. Water resource and climate enthusiasts can appreciate the intricate balance of engineering and environmental stewardship embodied by Basil Mack Dam.
Year Completed |
1999 |
Dam Length |
230 |
Dam Height |
13 |
River Or Stream |
SANDY RUN |
Primary Dam Type |
Earth |
Surface Area |
7 |
Nid Storage |
60 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
13 |
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.
Basil Mack Dam