SHH Labyrinth Weir and Stream Improvements

The South Holston Labyrinth Weir is located at South Fork Holston River Mile (RM) 48.49, approximately 1.2 miles downstream of the South Holston Dam, near Bristol, Tennessee. The South Holston Labyrinth Weir has experienced degradation as a result of use, primarily on the downstream side of the weir due to scour. In general, scour has occurred downstream of the weir’s 24-inch and 12-inch diameter discharge pipes causing scour holes in the stream channels and undermining of portions of the weir concrete foundation. In addition, abrasion of some weir structures, malfunctioning of some valves, as well as erosion and settlement of some of the downstream abutments have been identified.

Repairs and maintenance are required to ensure the longevity and optimal performance of the labyrinth weir system.

Repair and Maintenance Items

• Repair the scour holes in all the bays below the 12-inch and 24-inch diameter discharge pipes.
• Install a splash plate in all the bays below the 12-inch and 24-inch diameter discharge pipes to dissipate energy.
• Perform bank stabilization upstream and downstream of all four observation platforms.
• A portion of the parking lot adjacent to South Holston View Dam Road will be used as a laydown area and will have to be closed. See below.

Phase 1 will be initiated August 2020 with an expected duration of 2-3 months. Phase 2 will most likely be initiated in March 2021 with a duration of 3-4 months.

Thank you to Jeff Ogden and Terry Shannon for sharing this information with the local TU Chapters.