The state water commission consists of the governor, agriculture commissioner, and eight other members appointed by the governor who shall take into account reasonable geographic considerations in making the appointments with the intent of having each of the eight major drainage basins represented by a commissioner who resides in the basin. The major drainage basins are the upper Missouri River basin; the lower Missouri River basin; the James River basin; the upper Red River basin; the lower Red River basin; the Mouse River basin; the Devils Lake basin; and the Little Missouri River, upper Heart River, and upper Cannonball River basin. The governor or the agriculture commissioner, or both, may appoint a representative to serve in that official’s capacity at meetings that official is unable to attend. The eight appointive members of the commission must be appointed for a term of six years each with the terms of office so arranged that not more than four terms expire on the first day of July of each odd-numbered year. Each appointive member must be a qualified elector of the state and is subject to removal by judicial procedure. In case of a vacancy, the vacancy must be filled by appointment by the governor for the remainder of the unexpired term. Before entering upon the discharge of official duties, each appointive member shall take, subscribe, and file with the secretary of state the oath prescribed for civil officers.