Another Phase Has Been Completed In The Boone Dam Construction Project And Another Phase Is Set To Begin. The Tennessee Valley Authority Said Workers Have Completed Building Two Rock Berms Upstream And Downstream. The Next Major Project Will Cost 450 Million. Workers Will Begin To Install An Underground Cutoff Wall. TVA Is Now In The Process Of Securing A Subcontractor. The Project Is In Its Fourth Year Of A Seven Year Effort To Stop Sediment Seepage That Threatened The Stability Of The Dam. Its Expected To Be Completed In 2022.