Mo. Rev. Stat. § 246.067
When any lands, included in a drainage district or levee district organized under the laws of this state, are now or hereafter divided into lots in an incorporated city, town, or village, the county commission in the case of a county commission district organization, or the circuit court in which a district was organized in the case of a circuit court district organization, if in the opinion of said court or county commission the expense of extending and collecting the taxes levied on said lots make such extension and collection uneconomical, may by order of record cancel the benefits assessed against said lands, so that after such cancellation said lands will not be liable for drainage or levee taxes in such district; provided, however, no such benefits shall be cancelled while the district has outstanding unpaid bond obligations; provided, however, this section shall not be applicable to a drainage or levee district organized and existing wholly within a city or town of this state.
§ 246.067, RSMo