(1) Any city, village, or incorporated town having a population of 500,000 or more may, by an ordinance containing provisions substantially the same as those in this Act with respect to the registration of irrigation contractors, provide for the registration of irrigation contractors within such city, village, or incorporated town. Upon the enactment of the ordinance, the provisions of this Act relating to irrigation contractors shall not apply within any such municipality except as otherwise provided herein.
     (2) Any person registered as an irrigation contractor pursuant to such ordinance, or registered by the Department under this Act, may install or supervise the installation of lawn sprinkler systems anywhere in this State.
     (3) Any municipality enacting an ordinance pursuant to this Section shall maintain a current record similar to that required of the Department by Section 2.5 of this Act, and shall provide the Department with a copy thereof. The Department shall be advised of changes in such record at least every 6 months.