Post Oak Island Dredge
U.S. Army Corps of Engineers (USACE), TVA and river tow operators perform periodic inspections and reportings of the depth and condition of the Tennessee River navigation channel. It has been determined that material has accumulated within the authorized navigation channel at river mile (TRM) 631.8 near Looney Island, Fort Loudoun Reservoir, Knox County, Tennessee. This section of navigation channel, about 16 miles downstream of downtown Knoxville, has not been dredged since 1998. River bottom sediment removal and open water disposal of this material between TRM 631.2 and TRM 632.2 is necessary to restore adequate navigation depths to this reach of the river. Dredging would occur to elevation 796.0-foot mean sea level (msl), which is 11 feet below Fort Loudoun Reservoir’s normal minimum pool elevation of 807.0-foot msl. This would provide the minimum 9-foot navigation depth plus 2 feet of additional depth for safety and to allow a few years of sediment accumulation before dredging is needed again. This material, amounting to about 120,000 cubic yards, would be redistributed in 25 to 40 feet of water in the vicinity of TRM 631.2 where potential of further sediment movement by river scouring would be low.
Because the proposal involves work in the Tennessee River, would assist TVA in carrying out its statutory obligation and is in furtherance of the TVA Act, TVA cooperated with USACE in the preparation of an environmental assessment for this proposal. Because dredge material would be redistributed in the reservoir, TVA is also reviewing this dredge proposal for approval under Section 26a of the TVA Act. Fort Loudoun Reservoir is presently classified as not supporting designated uses due to PCB contamination and other chemicals in bottom sediments are analyzed to evaluate effects on the aquatic environment.
A copy of the USACE final EA and FONSI (referenced attachment) can be provided upon request. Write Stanford E. Davis, Tennessee Valley Authority, 400 W. Summit Hill Dr. WT 8C, Knoxville, TN 37902, or call him at 865-632-2915.
Comments, questions or a request for a copy of the EA may also be sent via e-mail to Stanford E. Davis.