Mo. Rev. Stat. § 245.335

At the term of the county commission at which said levee district may be laid off, or at any subsequent term thereof, the said commission shall appoint three directors of levees, who shall be landholders within the county for the levee district of which the county is the whole or part thereof, one of which directors shall hold his said office for the term of one year, one for the term of two years, and one for the term of three years, and until their successors are duly appointed and qualified; and the said commission shall annually thereafter appoint one director to take the place of the director whose official term expires, possessing the same qualifications as the director first appointed, who shall hold his office for the term of three years.