Mo. Rev. Stat. § 88.917
Every city now having or which may at any time hereafter have a population of three hundred thousand inhabitants or over shall have at all times the power to establish the grade and change the grade already established of any street, alley, avenue, public highway or public place, or any part thereof, as often as it may be deemed best for the public interest, and to cause the same or any part thereof to be graded to the established grade or to any change thereof. Provided, however, that when a change is proposed to be made in the grade of any street, alley, avenue, public highway or public place, or any part thereof, which has once been established, the city shall by ordinance declare the work of improvement to be necessary, and cause such ordinance, or the substance thereof, to be published in the newspaper doing the city printing, for ten days, Sundays included. Unless the resident owners of the city who shall own the majority in front feet of all the lands belonging to such residents fronting on the street, alley, avenue, public highway, public place, or part thereof to be improved, within thirty days after the first day of the publication of such ordinance, file with the city register their remonstrance against the proposed change, then the ordinance to cause the proposed change to be made shall become effective. Provided further, however, that when the charter of any such city shall require that such ordinance shall, before being passed, be recommended by a board of public improvements, or other authority of such city, then the same shall, before being passed, be recommended as therein required. If the remonstrance of the resident property owners above mentioned shall be filed with the city register, as herein provided, the ordinance to make the proposed change in the grade of such street, alley, avenue, public highway or public place, or any part thereof, shall not become effective until a sufficient number of the persons so remonstrating or their grantees shall, in writing, withdraw their names or the property represented by them from such remonstrance, so that said remonstrance shall cease to represent a majority of the resident owners as above provided.
§ 88.917, RSMo