Big Ridge Dam
Big Ridge Dam is a gravity dam located in Union County, Tennessee, built in 1936. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Big Ridge Dam
Big Ridge Dam is a dam in Union, Tennessee. The dam is owned by Tdec (state). It impounds the Trib-norris Lake near Norris.
The dam stands 50 feet tall and stretches 197 feet across, creates a reservoir covering 46 acres, has a maximum storage capacity of 1,100 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1936, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 01/12/2026.
At 50 feet, this dam is taller than 93% of dams nationwide.
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Location
| State | Tennessee |
| County | Union |
| Nearest City | Norris |
| River/Stream | Trib-norris Lake |
| Coordinates | 36.24972, -83.93444 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 50 ft |
| Dam Length | 197.5 ft |
| Year Completed | 1936 (90 years old) |
Storage & Hydraulics
| NID Storage | 1,100 acre-ft |
| Max Storage | 1,100 acre-ft |
| Normal Storage | 1,027 acre-ft |
| Surface Area | 46 acres |
| Drainage Area | 1 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Owner | Tdec |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 01/12/2026 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | TN17302 |
| Federal ID | TN17302 |
| More Info | State Dam Safety Program |