Mo. Rev. Stat. § 242.510
In all cases where drainage districts have been organized under proceedings in any circuit court of the state, prior to April 8, 1905, the board of supervisors, instead of having commissioners appointed to assess benefits or damages, may, for the purpose of constructing drainage works in their district, as well as for purpose of maintaining and keeping same in repair, and for paying principal and interest upon bonds, if any are issued, levy each year, so long as necessary, a level rate of taxation, not exceeding one dollar in any one year, upon each acre of the lands in said district, and which levy shall be made and certified by such board to the collector of revenue of the proper county not later than the first day of September of each year, and which shall by the clerk be extended upon the tax books of the county for that year and collected by the collector in the same manner as other taxes.
§ 242.510, RSMo