Mo. Rev. Stat. § 88.680
The cost of paving, macadamizing, guttering and curbing (where such curb is set out into the street beyond the sidewalks) all streets, avenues, alleys and other highways, or any part thereof or any connection therewith, and repairing the same, and for doing all excavating and grading necessary for the same, after said streets, avenues, alleys and other highways, or parts thereof or connections therewith, have been first brought to grade, as provided in section 88.670, shall be levied as a special assessment upon all lots and pieces of ground upon either side of such street, avenue, alley or other highway, or part thereof or connection therewith, abutting thereon, along the distance improved, in proportion to the front foot; provided, that the cost of paving, macadamizing, curbing and guttering any street, avenue, alley or highway, or any part thereof, and the cost of repairing and cleaning of the same and of making and repairing sidewalks may be paid out of the general revenue fund of the city or other funds which the city may have for such purposes, if the board of aldermen so desires, in which case the proceedings of the city for such improvements shall specify that payment will be made out of the general revenue funds or other funds in whole or in part.
§ 88.680, RSMo