In any case of grade separation under the provisions of this chapter, no plan shall be adopted by the department or order made requiring a grade of any railroad track that shall exceed the established maximum or ruling grade governing the operation of that division or part of the railroad on which separation of grades is to be made without the consent of the company operating said railroad; nor shall the track or tracks of the companies concerned be required to be placed below high-water mark at the point where such change is made.
IC 8-6-1-6