(a) In this section, "sole expense" means the actual cost of relocating, raising, lowering, rerouting, changing the grade of, or altering the construction of a facility described by Subsection (b) in providing comparable replacement without enhancement of the facility, after deducting from that cost the net salvage value of the old facility.
(b) If the authority's exercise of the power of eminent domain, the power of relocation, or any other power makes necessary the relocation, raising, rerouting, changing the grade, or alteration of the construction of a highway, a railroad, an electric transmission line, a telephone or telegraph property or facility, or a pipeline, the necessary action shall be accomplished at the sole expense of the authority.