50 ILCS 460/15

The provisions of this Act are intended to be supplemental to and in addition to all other powers or authorities granted to any governmental unit, shall be construed liberally, and shall not be construed as a limitation of any power or authority otherwise granted. Any governmental unit may use the provisions of this Act by making an election referring to this Act in the special assessment ordinance. In addition, a governmental unit may use the provisions of this Act that relate exclusively to Supplemental Act Assessment Bonds by making an election referring to this Act in any ordinance or resolution passed subsequent to the special assessment ordinance.