The board of directors shall, from time to time after the adoption of said official plan, have the power to modify, amend or extend the same, provided that upon the making of any such modification, amendment or extension thereof, the board of directors shall cause notice to be given and shall conduct a hearing, all as provided in Section 7 of this act, and shall not adopt any modification, amendment, or extension until the notice has been given and hearing held as herein provided.
Laws 1959, p. 393, § 8, emerg. eff. July 15, 1959.