(1) Each Regional Corporation is to be governed by a Board.(2) The Board of a Regional Corporation is to comprise (a) the chairperson appointed by the Owners' Representatives for that Regional Corporation under section 21(5)(a) ; and(b) 3 common directors appointed by the Owners' Representatives for that Regional Corporation under section 22 ; and(c) 2 regional directors appointed by the Owners' Representatives for that Regional Corporation under section 23 .(3) If at any time a vacancy occurs on the Board of a Regional Corporation, the Owners' Representatives for that Regional Corporation must, as soon as is practicable, do all things necessary to appoint a person to fill that vacancy in accordance with the procedures set out in this Act.