Johnson Creek #4 Reservoir Report
Nearby: Johnson Creek #10 Johnson Creek #5
Last Updated: February 13, 2026
Johnson Creek #4, also known as Johnson Creek Dam 4, is a privately owned earth dam located in Oak Grove, Tennessee.
Summary
Built in 1959 by the USDA NRCS, this dam along Hart Creek serves the primary purpose of flood risk reduction. With a hydraulic height of 17.5 feet and a structural height of 28.5 feet, it stands as a significant structure in the area.
Covering a drainage area of 3.47 square miles, Johnson Creek #4 has a normal storage capacity of 263 acre-feet and a maximum storage capacity of 1370 acre-feet. Although the dam is uncontrolled, its spillway type and width are noted as essential features for managing potential flood events. The dam's hazard potential is classified as significant, with a moderate risk rating of 3.
Despite not being state-regulated or inspected, Johnson Creek #4 remains a crucial element in the flood risk management strategy for the region. With its historical significance and impact on the surrounding community, this dam stands as a testament to the collaborative efforts between private owners and government agencies to safeguard water resources and mitigate climate-related risks in Tennessee.
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15-Day Weather Outlook
Year Completed |
1959 |
Dam Length |
1033 |
River Or Stream |
HART CREEK |
Primary Dam Type |
Earth |
Surface Area |
62 |
Hydraulic Height |
17.5 |
Drainage Area |
3.47 |
Nid Storage |
1370 |
Structural Height |
28.5 |
Outlet Gates |
None |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
29 |
Seasonal Comparison
5-Day Hourly Forecast Detail
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 Creek #4