A city of the first class may provide for the grading, repairing, and sprinkling of any street, avenue, or alley, and the construction of bridges, culverts, and sewers, and shall defray the repairs of the street, avenue, alley, bridge, culvert, or sewer out of the proper fund of such city, but no street shall be graded except the street ordered to be done by the affirmative vote of two-thirds of the city council. On written petition of not less than one-half the owners of street front of the land fronting on any street or any specified part thereof, the mayor and city council may order such street or any specified part thereof to be sprinkled with water at such time or times as the city council may deem proper. Such sprinkling shall be done by contract awarded to the lowest responsible bidder in each case, and for the entire city or specified district thereof. To pay the expenses of such sprinkling the city council may make special assessments upon the lands abutting upon such street or specified part thereof either on the valuation thereof, as listed for taxation, or by foot front. Such assessment shall be collected by special taxation.