Minn. Stat. § 394.312: RELATION TO OTHER COUNTY AUTHORITY.

All official controls in effect on August 1, 1974, shall remain in full force and effect until amended or repealed whether such controls were adopted by resolution of the board or by ordinance and whether or not comprehensive plans had been adopted before the official controls were adopted. Any official controls and any procedures for the administration of official controls which are in existence on August 1, 1974, shall be brought into compliance with Laws 1974, chapter 571, within four years from August 1, 1974.