Mo. Rev. Stat. § 537.410

Every corporation, person or association of persons who shall construct a boom across or in any of the streams or waters of this state shall be liable for all damages arising from backwater or overflow caused by the construction of such boom or the accumulation of logs, lumber or other floatables therein, and in all cases where judgment is rendered in any court for any damages occasioned as herein provided, the court shall allow the plaintiff a reasonable attorney's fee, to be taxed as costs in the case.