Thunder Hollow Dam is an earth dam located in Union County, Tennessee, built in 1974. It carries a Significant hazard potential classification.
Dam profile
NID height · 46 ft46 ft tall and 357 ft long, taller than 91% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Thunder Hollow Dam
Thunder Hollow Dam is a dam in Union, Tennessee. The dam is owned by Simmerly, Mr. Dana (private). It impounds the Bullrun Creek near Pleasant Grove.
The dam stands 46 feet tall and stretches 357 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 34 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1974, the structure is well into its service life at over 50 years old.
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. The most recent inspection on record was 02/11/2020.
At 46 feet, this dam is taller than 91% of dams nationwide.
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Location
| State | Tennessee |
| County | Union |
| Nearest City | Pleasant Grove |
| River/Stream | Bullrun Creek |
| Coordinates | 36.20500, -83.83028 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 46 ft |
| Dam Length | 357 ft |
| Year Completed | 1974 (52 years old) |
Storage & Hydraulics
| NID Storage | 34 acre-ft |
| Max Storage | 34 acre-ft |
| Normal Storage | 25 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Owner | Simmerly, Mr. Dana |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 02/11/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | TN17301 |
| Federal ID | TN17301 |
| More Info | State Dam Safety Program |