TENNESSEE VALLEY AUTHORITY RESERVATION – On Tuesday, Public and Community Relations Representative, Scott Fiedler, along with a cadre of TVA engineers and construction managers, let a media tour of Wilson Dam which highlighted some planned major renovations to the roadway above the century-old structure.
Scott Fiedler, TVA
For years, TVA engineers knew that the thoroughfare which, since the 1920’s has connected Lauderdale and Colbert Counties was showing its age. This will be the 2nd refurbishing of the via since Wilson Dam, which predates the Tennessee Valley Authority, was constructed.
The roadway, originally made of brick that was laid upon a 2” bed of concrete in the 1920’s underwent a major resurfacing in the 1950’s when the new lock and an additional steel superstructure viaduct was constructed over the lock were constructed. The original roadway was rebuilt by removing the brick and replacing it with a non-reinforced concrete surface. This road is not actually part of Wilson Dam. It sits above the structure of the dam, so when the work is undertaken to remove and rework the roadway, it should have no impact on the structure of the dam at all. The original concrete underlayment was poured on top of the multi-arch structural elements above the spillways. Problem is, over the decades the underlayment has deteriorated and has actually de-bonded from the arch structure of the dam itself.
Ben Bayard, TVA Structural Engineer
Driving over the dam, you can see cracks in the concrete roadway. These fissures are evidence of a lack of support which was caused by the deterioration. According to TVA Engineer, Ben Byard, this has to be fixed. And it’s going to take some work to get that done. 
The TVA has issued a draft Environmental Assessment (EA) to refurbish and repair the dam deck and other concrete surfaces and to stop the flow of water through the deck and parapets of the Wilson Dam Bridge. Construction of the Wilson Dam began in 1918 and was completed in 1926. In May 1933, TVA acquired the dam from the U.S. Army Corps of Engineers (USACE). TVA owns the Wilson Dam while the USACE Nashville District operates the Wilson Dam locks for TVA. Both the dam and bridge are listed in the National Register of Historic Places as a National Historic Landmark.
Over the years, the downstream face where the concrete arches interface with the parapet have developed widespread spalls (areas where chips, splinters or fragments are broken off) with efflorescence (whitish powdery substance due to migration of mineral rich water through the porous concrete where it evaporates) and visible water movement. In addition, the sidewalk, curb, and deck have developed widespread cracking
When TVA closes the roadway over Wilson Dam this January construction crews will use machines to cut and lift out the old concrete roadway and what remains of the deteriorated concrete underlayment. No damage to Wilson Dam is anticipated as already mentioned, because this roadway is not actually part of the foundational structure of the dam. Engineers suggest that the removal and replacement of a new concrete roadway will take 9 months or more to complete. This massive project is out for bid at this time.
News Media Tour of Wilson Dam roadway restoration project plans
While the road work is being done, certain parts of the fascia will be removed and replaced where there has been significant aging over the last 100 years
Wilson Dam will be closed to all traffic beginning in January of 2020 and will remain closed for 9 months or more while the work is underway. Once the repairs are completed, the roadway over Wilson will once again be open to traffic.
