Avalon Reservoir Report
Nearby: Avalon - Canal Embankment Mayo
Last Updated: December 5, 2025
Avalon is a private hydroelectric dam located on the Mayo River in Mayodan, North Carolina.
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Summary
Built in 1900, this concrete, gravity, and masonry dam stands at a height of 30 feet and has a structural height of 18 feet. With a length of 456 feet and a storage capacity of 100 acre-feet, Avalon serves as a vital water resource for the region, providing hydroelectric power and controlling the flow of the Mayo River.
Managed by the Federal Energy Regulatory Commission, Avalon has a low hazard potential and a very high risk assessment rating. Despite its age, the dam has not undergone any recent condition assessments, but regular inspections by the FERC ensure its safety and functionality. The controlled spillway and rock foundations contribute to the dam's stability, while its location in Rockingham County makes it a key element in the region's water infrastructure.
As a historical and essential piece of North Carolina's water management system, Avalon represents a balance between energy production and environmental conservation. With its unique design and purpose, this dam stands as a testament to the ingenuity of early 20th-century engineering and continues to play a crucial role in the sustainable use of water resources in the Mayo River watershed.
Year Completed |
1900 |
Dam Length |
456 |
Dam Height |
30 |
River Or Stream |
Mayo River |
Surface Area |
11 |
Hydraulic Height |
18 |
Drainage Area |
310 |
Nid Storage |
100 |
Structural Height |
18 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dan River Near Wentworth
|
545cfs |
Mayo River Near Price
|
130cfs |
Dan R At Pine Hall
|
235cfs |
North Mayo River Near Spencer
|
56cfs |
Smith River At Eden
|
204cfs |
South Mayo River Near Nettleridge
|
45cfs |
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.
Avalon