(1)Where by reason of exceptional shortage of rain or other emergency it appears to a river purification board that it is necessary to impose a temporary restriction on the abstraction of water, they may restrict or suspend the operation of any licence under this Act relating to a stream or locality affected by the shortage or emergency:
Provided that if occasioned by exceptional shortage of rain that restriction or, as the case may be, that suspension shall apply equitably to all licences relating to the stream or locality in question.
(2)Where by reason of abundance of water it appears to a river purification board that restrictions on the abstraction of water from a stream or locality may be temporarily relaxed or suspended, the board may so declare, and while such a declaration has effect the operation of licences under this Act relating to the stream or locality in question shall be relaxed to the extent authorised by the declaration (which shall apply equitably to all such licences) or, as the case may be, shall be suspended.
(3)A river purification board shall communicate any decision taken by them under this section to the holders of licences affected thereby.