In assessing the cost for the improvements and facilities herein provided in Section 2-232, the Council shall assess against the abutting property for improvements provided in Section 2-232 on a front foot basis as herein provided and against the real property located in the areas affected for improvements in Sections 2-235 and 2-237 on an ad valorem or unit of service tax basis as herein provided and collect from the owners thereof the entire cost of constructing roadbeds, alleys, curbs, sidewalks, gutters, and street improvements, including the cost of street and public alley intersections and systems for the disposition of surface waters. All construction costs, excavation costs, cost of preparation of preliminary plans, advertising for bids, engineering fees, attorney fees, operation costs, and all other costs, including administration and collection costs of the assessments to be levied. At no time shall the Council expend general funds or allocate money received from the State, or any other agency, in the carrying out of the powers of this Division except as hereinbefore provided. In the event in any one year the ad valorem tax or special assessment or unit of service tax levied is insufficient for the purpose of paying the principal and interest maturities of any bonds, notes, or certificates of indebtedness issued under the provisions of Section 2-241 and general funds are used, then, and in that event, the following year the ad valorem tax or special assessment or unit of service tax levied shall be increased in the area served to the extent necessary to reimburse the general funds used the previous year.