Piney Run Dam Reservoir Report

Last Updated: December 5, 2025

Piney Run Dam, also known as Lake Werowance, is a privately owned earth dam located in Fairfax, Virginia, along the Piney Run river.


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Summary

Standing at 15 feet tall and 180 feet long, this dam serves a primary purpose that is categorized as 'Other'. With a maximum storage capacity of 167 acre-feet and a normal storage of 58 acre-feet, Piney Run Dam plays a crucial role in water resource management in the area.

The dam's hazard potential is currently labeled as 'Undetermined', with its condition assessment marked as 'Not Rated'. Despite this, the structure has not undergone recent inspections and lacks a formal emergency action plan. As a water resource and climate enthusiast, one may find Piney Run Dam to be an interesting case study in terms of its design, purpose, and maintenance practices. Its location in a highly populated area like Fairfax highlights the importance of proper management and monitoring of such critical infrastructure.

With its unique characteristics and uncertain hazard potential, Piney Run Dam presents an intriguing subject for further exploration and analysis in the realm of water resource and climate studies. As a privately owned structure in Virginia, its role in ensuring water supply, flood control, and environmental protection underscores the need for ongoing assessment and regulation to safeguard the surrounding community and ecosystem.

Dam Length

180

Dam Height

15

River Or Stream

Piney Run

Primary Dam Type

Earth

Surface Area

15

Hydraulic Height

15

Nid Storage

167

Structural Height

15

Hazard Potential

Undetermined

Nid Height

15
       
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.