Glen Lyn Fly Ash Dam Reservoir Report

Last Updated: December 5, 2025

Located in Giles, Virginia, the Glen Lyn Fly Ash Dam is a significant earth dam with a height of 43 feet and a length of 2230 feet.


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Summary

This dam, built for purposes other than flood control or water supply, stands as a crucial infrastructure managed by the Department of Conservation and Recreation. With a normal storage capacity of 80 acre-feet and a maximum storage of 300 acre-feet, this dam plays a vital role in controlling water flow and storage in the New River.

The dam, with a hazard potential rated as high, has a satisfactory condition assessment as of October 2018. Regular inspections are conducted to ensure its safety and functionality. While the last Emergency Action Plan (EAP) revision was in September 2019, the dam's risk assessment and management measures remain unspecified. Despite lacking certain details, the Glen Lyn Fly Ash Dam serves as a critical asset in water resource management for the region.

With its location along the New River and its role in water storage and control, the Glen Lyn Fly Ash Dam is a key component in Virginia's water infrastructure. Managed by the Department of Conservation and Recreation, this earth dam stands as a testament to the state's commitment to regulating and monitoring its water resources. As climate change impacts water availability and quality, maintaining the safety and efficiency of structures like the Glen Lyn Fly Ash Dam becomes increasingly crucial for the region's water security.

Dam Length

2230

Dam Height

43

River Or Stream

NEW RIVER(OFF STREAM)

Primary Dam Type

Earth

Surface Area

4.2

Hydraulic Height

43

Drainage Area

0.01

Nid Storage

300

Structural Height

43

Hazard Potential

High

Nid Height

43
       
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.