Gunners Lake (Wisteria Drive) Reservoir Report

Last Updated: December 5, 2025

Gunners Lake (Wisteria Drive) is a local government-owned earth dam located in Montgomery, Maryland, designed by Johnson, Mirmiram and Thompson.


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Summary

Completed in 1985, this dam serves the primary purpose of flood risk reduction along Gunners Branch. Standing at a height of 28 feet and with a length of 1700 feet, Gunners Lake has a storage capacity of 646 acre-feet and a normal storage of 145 acre-feet. The dam's spillway type is uncontrolled with a width of 59 feet, and it has a significant hazard potential with a satisfactory condition assessment as of June 2018.

The dam has a moderate risk rating (3) and undergoes inspections every three years, with the last inspection conducted in August 2021. The Emergency Action Plan (EAP) for Gunners Lake was last revised in April 2021. The dam's outlet gates consist of valves with a quantity of 0. While the dam's condition is currently satisfactory, the risk assessment indicates potential hazards that require management measures to mitigate any adverse effects. Gunners Lake remains a vital structure in the area's water resource management, providing essential flood risk reduction benefits to the community.

Years Modified

2001 - Structural

Year Completed

1985

Dam Length

1700

Dam Height

28

River Or Stream

Gunners Branch

Primary Dam Type

Earth

Surface Area

20

Drainage Area

2

Nid Storage

646

Outlet Gates

Valve - 0

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

28
       
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.