(1) After the approval of a master plan or local plan—
(a) the local planning authority shall keep under constant examination and review factors which affect or are likely to affect the planning area and if, as a result of such examination or review, the assumptions upon which the master plan or local plan are based are found to be no longer valid, the local planning authority shall consider appropriate proposals for the alteration, repeal or replacement of such plan; (b) the Minister may at any time require the local planning authority, other than a scheduled local planning authority, to make proposals for the alteration, repeal or replacement of the master plan or local plan in relation to such matters and within such period as he may direct.
(2) Subject to subsection (3)—
(a) sections fifteen and sixteen shall apply, mutatis mutandis, to any proposals for the alteration, repeal or replacement of a master plan and the local planning authority shall, in submitting such proposals to the Minister, attach thereto a report on any study or review in terms of subsection (1) of section thirteen;
(b) sections eighteen and nineteen shall apply, mutatis mutandis, to any proposals for the alteration, repeal or replacement of a local plan and the local planning authority shall, in considering such proposals, have regard to the report on any study or review in terms of subsection (1) of section thirteen.
(3) In the case of any proposed alteration to a master plan or local plan, the Minister may, upon application by a local planning authority, other than a scheduled local planning authority, if, in his opinion, the proposed alteration is one which would not adversely affect the interests or rights of a substantial number of people— (a) direct that all or any of the provisions of—
(i) section fifteen shall not apply to the proposed alteration of the master plan; or
(ii) sections eighteen and nineteen shall not apply to the proposed alteration of the local plan; as the case may be; and
(b) include in his direction the procedure with which the local planning authority shall comply in respect of the proposed alteration:
Provided that if the Minister has directed that public notice of the proposed alteration shall not be required to be given, the local planning authority shall give notice of the proposed alteration to every owner of property adjacent to any land affected by the proposed alteration.