Johnston Lake Dam Reservoir Report

Last Updated: December 5, 2025

Johnston Lake Dam, located in Armuchee, Georgia, is a privately owned structure primarily used for recreation.


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Summary

Built in 1958, this earth dam stands at a height of 11.8 feet and has a hydraulic height of 14.6 feet. With a storage capacity of 192 acre-feet and a normal storage of 132 acre-feet, the dam covers a surface area of 22 acres and drains an area of 49.6 square miles.

Despite being unregulated by the state, Johnston Lake Dam has a low hazard potential and is considered to have a moderate risk level. The dam features an uncontrolled spillway and outlet gates, with its last inspection conducted in March 2018. While the condition assessment is listed as "Not Rated," the dam's risk management measures and emergency action plans are not specified in the data.

Water resource and climate enthusiasts interested in Johnston Lake Dam will find it to be a quaint recreational spot in Floyd County, Georgia. With its picturesque surroundings and moderate risk level, the dam serves as a reminder of the importance of maintaining and monitoring earth structures for both safety and enjoyment.

Year Completed

1958

Dam Length

1800

Dam Height

11.8

River Or Stream

Unknown

Primary Dam Type

Earth

Surface Area

22

Hydraulic Height

14.6

Drainage Area

49.6

Nid Storage

192

Outlet Gates

Uncontrolled

Hazard Potential

Low

Foundations

Unlisted/Unknown

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.