16.—(1) If a member of the Authority resigns, becomes disqualified or otherwise ceases to be a member of the Authority before the expiry of his period of office, the council which appointed him shall appoint a representative to replace him, who shall come into office on the date of his appointment and, unless he resigns, becomes disqualified or otherwise ceases to be a member of the Authority, shall hold office for the remainder of the period for which his predecessor would have held office had he not resigned, become disqualified or otherwise ceased to be a member of the Authority.
(2) If a member of the Authority resigns, becomes disqualified or otherwise ceases to be a member of the Authority within six months before the end of his term of office, the council which appointed him shall not be required to appoint a representative to replace him for the remainder of such term unless, on the occurrence of the vacancy (or in the case of a number of simultaneous vacancies, the occurrence of the vacancies) the total number of unfilled vacancies in the membership of the Authority exceeds one third of the number of members of the Authority referred to in paragraph 11.