Fox Lake Dam Reservoir Report

Last Updated: December 5, 2025

Fox Lake Dam, located in Fairfax, Virginia, is a privately owned structure regulated by the Department of Conservation and Recreation.


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Summary

Standing at 33 feet high and spanning 450 feet in length, this earth dam serves primarily for recreational purposes with a storage capacity of 108 acre-feet. Situated on the TR-Difficult Run river, the dam's hazard potential is classified as low, and its condition assessment is deemed satisfactory as of the last inspection in July 2020.

Despite its low hazard potential, Fox Lake Dam plays a crucial role in providing recreational opportunities for the local community while also serving as a water resource management structure. With a surface area of 7 acres and a drainage area of 0.17 square miles, the dam contributes to the conservation and utilization of water resources in the region. Furthermore, its satisfactory condition and regular inspections ensure its continued functionality and safety for both recreational and water management purposes.

In the event of an emergency, it is essential for the owners of Fox Lake Dam to have an Emergency Action Plan (EAP) in place, although the last revision of the plan dates back to April 2013. With proper risk assessment and management measures, the dam can continue to serve its intended purposes while mitigating potential hazards. As climate change continues to impact water resources, structures like Fox Lake Dam play a vital role in ensuring water security and recreational opportunities for the community.

Dam Length

450

Dam Height

33

River Or Stream

TR-Difficult Run

Primary Dam Type

Earth

Surface Area

7

Hydraulic Height

33

Drainage Area

0.17

Nid Storage

108

Structural Height

33

Hazard Potential

Low

Nid Height

33
       
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.