13. Date of coming into operation of the Regional Plan.

(1) Immediately after the Regional Plan has been finally prepared, the Board shall publish, in such manner as may be prescribed, a notice stating that the Regional Plan has been finally prepared by it and naming the places where a copy of the Regional Plan may be inspected at all reasonable hours and upon the date of first publication of the aforesaid notice, the Regional Plan shall come into operation.

(2) The publication of the Regional Plan, after previous publication, as required by section 12, shall be conclusive proof that the Regional Plan has been duly prepared.