Great Falls-Dearborn Diversion Dam Reservoir Report
Last Updated: December 15, 2025
The Great Falls-Dearborn Diversion Dam, also known as the Mountain Island Diverting Spillway, is a captivating structure located in Great Falls, South Carolina.
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Summary
Built in 1907 by the Southern Power Company, this gravity dam stands at a height of 15 feet and spans 1558 feet in length. Its primary purpose is hydroelectric power generation, utilizing the flow of the Catawba River to produce energy.
With a storage capacity of 2043 acre-feet and a surface area of 450 acres, the Great Falls-Dearborn Diversion Dam plays a crucial role in water management and energy production in the region. The dam features an uncontrolled spillway with a width matching its length, contributing to the efficient regulation of water flow. Despite its low hazard potential, the dam undergoes regular inspections by the Federal Energy Regulatory Commission to ensure its safety and reliability.
Overall, the Great Falls-Dearborn Diversion Dam is a historical and functional landmark that underscores the intersection of water resources and climate considerations. Its role in providing hydroelectric power while managing water flow exemplifies the importance of sustainable infrastructure in meeting energy needs and environmental challenges in the modern world.
Year Completed |
1907 |
Dam Length |
1558 |
Dam Height |
15 |
River Or Stream |
Catawba River |
Primary Dam Type |
Gravity |
Surface Area |
450 |
Hydraulic Height |
15 |
Drainage Area |
4140 |
Nid Storage |
2043 |
Structural Height |
15 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
15 |
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.
Great Falls-Dearborn Diversion Dam