(1) After every ten years from the date of coming into operation of the finally prepared Regional Plan, the Authority shall review such Regional Plan in its entirety and may, after such review, substitute it by fresh Regional Plan or may make such amendments or alterations therein, as may be found by it to be necessary.
(2) Where it is proposed to substitute a fresh Regional Plan in place of the Regional Plan which was previously finally prepared or where it is proposed to make any amendments or alterations in the finally prepared Regional Plan, such fresh Plan or, as the case may be, amendments or alterations in the finally prepared Regional Plan, shall be published and dealt with in the same manner as if it were the Regional Plan referred to in section 14 and 15 or as they were the amendments or alterations in the Regional Plan made under section 16 .