The Council shall levy special assessment taxes as follows: The Council shall levy a special assessment tax for the construction and reconstruction of roads, bridges, alleys, streets, sidewalks and curb and gutters, with storm drainage incident thereto, on a special benefit assessment basis, pursuant to Section 2-374. The Council shall levy special assessment taxes for the cost of municipal functions and services, including street lights, street signs, street cleaning and maintenance, but excluding garbage and trash collection, removal and disposition and site acquisition and operation, by an ad valorem tax levy against all of the properties assessed for County tax purposes within the area or that portion of the area where such are provided, pursuant to Section 2-375. The Council shall levy special assessment taxes for the costs of garbage and trash collection, removal and disposition, by a unit service tax, against those properties within the urban area or that portion of the urban area receiving trash and garbage removal and disposition service, pursuant to Section 2-375. The basis of the tax shall be the total cost of such service divided by the number of units served. The Council may vary the tax rate as between individual residential units, apartment units, commercial and industrial establishments. The Council shall levy a special assessment tax for the cost of the construction, maintenance and operation of storm drainage systems for the control and disposition of surface waters by an ad valorem tax against all of the properties assessed for County tax purposes within the watershed area served by such drainage system or that portion thereof served by any part of such system, pursuant to Section 2-376. All assessments made pursuant to this Division shall be calculated by the Office of Finance.