The legislative authority of a municipal corporation, for the purpose of making or causing a crossing improvement to be made, by ordinance may require the railroad company, in co-operation with the engineer of the municipal corporation, or the engineer designated in such ordinance, to prepare and submit to such legislative authority, within three months unless longer time is mutually agreed upon in writing, plans and specifications for such improvement, specifying the number, character, and location of all piers and supports which are to be permanently placed in any street or way in such municipal corporation, specifying the grades to be established for the streets and the height, character, and estimated cost of any viaduct or way above or below any railroad track, and the change of grade required to be made of such tracks, including the sidetracks and switches. In changing the grade of any railroad, no grade shall be required to exceed the established maximum or ruling grade governing the operations of engines of that division or part of the railroad on which the improvement is to be made, without the consent of the company, nor shall the company’s tracks or such highway, street, or way, be required to be placed below high-water mark.