Nothing contained in Sections 1 to 14, inclusive, of this act shall:
(a) Impair the provisions of law or ordinance directing the payment of revenues derived from public property into sinking funds or dedicating such revenues to specific purposes;
(b) Enlarge, alter, diminish, or affect in any way, any lease or conveyance made, or action taken prior to the creation of a port authority by any municipal corporation, or by any county;
(c) Impair or interfere with the exercise of any permit for the removal of sand or gravel, or other similar permits issued by this state or the United States. Laws 1959, p. 394, § 11, emerg. eff. July 15, 1959.