315 ILCS 30/11
Whenever the Department determines that a particular slum or blighted area, or any other area which may constitute a redevelopment project, as herein defined, should be acquired pursuant to the provisions of this Act, such determination together with an accurate description of the area included in such determination and the date on which the determination was made shall be immediately set forth in the records of the Department. Such determinations by the Department may be made from time to time and need not all be made at one time. Each such determination shall be evidenced by a resolution adopted by the Department.
The area of each such determination shall be specifically designated in the resolution as a "Slum and Blighted Area Redevelopment Project" or a "Blighted Vacant Area Redevelopment Project," according to the determination of the Department. A certified copy of such resolution shall be delivered to the governing body of the municipality in which the area is situated. No such determination shall be of any force or effect until such time as it has been approved by the governing body of the municipality in which the area is situated.
315 ILCS 30/11