55 ILCS 5/5-14001
Whenever in the judgment of the county board of any county, a portion or all of said county as a region, should have a plan made for the general purpose of guiding and accomplishing a co-ordinated, adjusted and harmonious development of said region, and of public improvements and utilities therein, and which plans will in the judgment of the county board, in accordance with the present and future needs of the region and of the State, best promote health, safety, morals, order, convenience, prosperity, efficiency and economy in the process of development and the general welfare of said region, the county board is hereby empowered by resolution of record to define the boundaries of such region and to create a regional planning commission for the making of a regional plan for such region so defined. The number of members of such commission, their method of appointment, and their power and authority in the making of such plan, shall be such as the county board may deem proper and not in conflict with law. Said Commission shall be a fact finding body and shall make such investigations and gather such statistics as it shall deem necessary for the planning and development of said region, and shall make a plan of said region to include all matter which it may deem necessary for the development of the region as provided above.
55 ILCS 5/5-14001