Mo. Rev. Stat. § 249.943

After construction of the improvement has been completed in accordance with the plans and specifications therefor, the governing body of the city or county shall compute the final costs of the improvement and apportion the costs among the property benefitted by such improvement in such equitable manner as the governing body shall determine, charging each parcel of property with its proportionate share of the costs, and by resolution, assess the final cost of the improvement or the amount of general obligation bonds issued or to be issued therefor as assessments against the property described in the assessment roll.