Black Lake Dam Reservoir Report

Last Updated: December 5, 2025

Black Lake Dam, located in Gwinnett, Georgia, was completed in 1958 and stands at a height of 16 feet with a hydraulic height of 17 feet.


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Summary

The primary purpose of this earth dam, designed by the SCS, is for recreation, offering a surface area of 13 acres and a storage capacity of 94 acre-feet. The dam, owned privately, is of low hazard potential and has not been rated for its condition assessment as of yet.

Although the dam has an uncontrolled spillway and outlet gates, it has a moderate risk assessment rating. The Savannah District of the USACE oversees the dam, which does not fall under state regulation. Black Lake Dam provides a scenic recreational area in DUNWOODY, Georgia, attracting water resource and climate enthusiasts to enjoy its serene surroundings and water activities. Its unique design and historical significance make it a noteworthy site for those interested in water management and conservation efforts in the region.

Year Completed

1958

Dam Length

700

Dam Height

16

River Or Stream

UNKNOWN

Primary Dam Type

Earth

Surface Area

13

Hydraulic Height

17

Drainage Area

190

Nid Storage

94

Structural Height

17

Outlet Gates

Uncontrolled

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

17
       
Seasonal Comparison

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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.