Cains Millpond Dam Reservoir Report

Last Updated: December 7, 2025

Cains Millpond Dam in South Carolina, completed in 1850, stands as a historical earth dam on Nasty Branch.


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Summary

This private-owned dam primarily serves recreational purposes and holds a storage capacity of 550 acre-feet. With a structural height of 9 feet and a length of 760 feet, the dam covers an area of 117 acres, providing a serene environment for outdoor activities.

Despite its historical significance, recent inspections have revealed that Cains Millpond Dam is in poor condition, with a significant hazard potential. The State of South Carolina regulates and inspects the dam regularly to ensure public safety. The dam's emergency action plan was last revised in 2008, and it is crucial for the owners to address the poor condition to mitigate potential risks and ensure the dam's longevity for future generations of water resource and climate enthusiasts.

As water resource and climate enthusiasts, it is essential to recognize the importance of maintaining and improving infrastructure like Cains Millpond Dam. By addressing the dam's poor condition and implementing risk management measures, we can preserve its historical significance while ensuring the safety of the surrounding community and the environment. Joining forces with regulatory agencies and local stakeholders can help create a sustainable plan for the dam's future, allowing it to continue serving as a valuable recreational resource in Sumter, South Carolina.

Year Completed

1850

Dam Length

760

Dam Height

9

River Or Stream

NASTY BRANCH

Primary Dam Type

Earth

Surface Area

117

Nid Storage

550

Hazard Potential

Significant

Foundations

Soil

Nid Height

9
       
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.