(a) In the event that the district or the water supply corporation, in the exercise of the power of eminent domain or power of relocation or any other power, makes necessary the relocation, raising, lowering, rerouting, or change in grade of or alteration in construction of any road, bridge, highway, railroad, electric transmission line, telegraph, or telephone properties, facilities, or pipelines, all necessary relocations, raising, lowering, rerouting, or change in grade or alteration of construction shall be done at the sole expense of the district or the water supply corporation unless otherwise agreed to in writing. Such relocation shall be accomplished in a timely manner so that the project of the district or the water supply corporation is not delayed.
(b) "Sole expense" means the actual cost of the relocation, raising, lowering, rerouting, or change in grade or alteration of construction and providing comparable replacement without enhancing the facilities after deducting from it the net salvage value derived from the old facility.