The procedure for making, altering, vacating, or abandoning a public improvement shall be governed by ordinance or to the extent not so governed, by State law. Action on any proposed public improvement, except a sidewalk or an improvement unanimously declared by the Council to be needed immediately due to an emergency, shall be suspended for six months upon filing of remonstrances by owners of two-thirds of the property to be specially assessed for the improvement. "Owner" in this section refers to the record holder of legal title. However, as to land being purchased under a recorded land sale contract, the purchaser shall be considered the owner.