Mo. Rev. Stat. § 245.196

In addition to any tax which may be levied pursuant to the provisions of section 245.180 or any other provision of sections 245.010 to 245.280, the board of supervisors may levy an annual benefit fee on nonpublic improvements on certain tracts of real estate in said district. The annual benefit fee shall be one thousand dollars for improvements with an assessed valuation of at least one million dollars but not more than five million dollars, five thousand dollars for improvements with an assessed valuation of more than five million dollars but not more than fifteen million dollars, and ten thousand dollars for improvements with an assessed valuation of more than fifteen million dollars.