Whenever, as the result of the construction of any dam, reservoir, or other improvement under the provisions of the Tennessee Valley Authority Act [16 U.S.C. 831 et seq.], or amendments thereto, including any improvement of the navigable channel to accommodate the growth of navigation or changes in navigation requirements within the reservoir created by any dam in the custody of the Tennessee Valley Authority, any bridge, trestle, or other highway or railroad structure located over, upon, or across the Tennessee River or any of its navigable tributaries, including approaches, fenders and appurtenances thereto, is endangered or otherwise adversely affected and damaged, including any interference with or impairment of its use, or, in the judgment of the Board of Directors of the Tennessee Valley Authority, needs to be raised, widened, or otherwise altered to provide the navigation clearances required for completion of the navigable channel to be provided by such improvement, to the extent that protection, alteration, reconstruction, relocation, or replacement is necessary or proper to preserve its safety or utility or to meet the requirements of navigation or flood control, or both, the owner or owners of such bridge, trestle, or structure shall be compensated by the Tennessee Valley Authority in the sum of the reasonable actual cost of such protection, alteration, reconstruction, relocation, or replacement: Provided, That in arriving at the amount of such compensation the bridge owner shall be charged with a sum which shall equal the net value to the owner of any direct and special benefits accruing to the owner from any improvement or addition or betterment of the altered, reconstructed, relocated, or replaced bridge, trestle, or structure. The Tennessee Valley Authority is empowered to contract with such owner with respect to any such protection, alteration, reconstruction, relocation, or replacement, the payment of the cost thereof and its proper division, which contract may provide either for money compensation or for the performance of all or any part of the work by the Tennessee Valley Authority.
In the event of a failure to agree upon the terms and conditions of any such contract, or upon any default in the performance of any contract entered into pursuant to this section, the bridge owner or the Tennessee Valley Authority shall have the right to bring suit to enforce its rights or for a declaration of its rights under this section, or under any such contract, in the district court of the United States for the district in which the property in question is located. In any such proceeding the court shall apportion the total cost of the work between the Tennessee Valley Authority and the owner in accord with the provisions contained in this section. The Tennessee Valley Authority’s share of the cost of any such protection, alteration, reconstruction, relocation, or replacement, under any contract made or judgment, award, or decree rendered under the provisions of this section may be paid out of any funds available for carrying out the provisions of the Tennessee Valley Authority Act, as amended, and appropriations for that purpose are hereby authorized: Provided, That, prior to such alteration, reconstruction, or relocation of said bridges, the location and plans shall be submitted to and approved by the Secretary of Transportation in accordance with existing laws.