Johnson Lake Dam Reservoir Report
Last Updated: December 5, 2025
Johnson Lake Dam, located in Calhoun, Georgia, is a privately owned structure designed by M.
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Summary
L. Johnson for the primary purpose of recreation. The dam, classified as an earth dam with a buttress core type, stands at a height of 12.9 feet and has a hydraulic height of 12.4 feet. With a storage capacity of 86.8 acre-feet and a normal storage level of 55 acre-feet, the dam creates a surface area of 11 acres and serves a drainage area of 364 square miles.
Despite being unregulated by the state and having a low hazard potential, Johnson Lake Dam poses a moderate risk due to its condition being "not rated." The last inspection, conducted in September 1984, revealed no major issues, but the dam has not been evaluated since. With uncontrolled spillways and outlet gates, the dam remains a key feature for recreational activities in the area, attracting water resource and climate enthusiasts seeking to explore the serene waters of Johnson Lake.
Dam Length |
315 |
Dam Height |
12.9 |
River Or Stream |
Name unknown |
Primary Dam Type |
Earth |
Surface Area |
11 |
Hydraulic Height |
12.4 |
Drainage Area |
364 |
Nid Storage |
86.8 |
Structural Height |
12.4 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
13 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Oostanaula River At Resaca
|
1020cfs |
Coosawattee River Near Pine Chapel
|
602cfs |
Two Run Creek Near Kingston
|
23cfs |
Oostanaula River Near Rome
|
1130cfs |
Etowah River Near Kingston
|
3190cfs |
Conasauga River At Tilton
|
356cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Johnson Lake Dam