70 ILCS 1710/2
It is determined and declared by the General Assembly that the welfare, health, prosperity, moral and general well-being of all the people of this State are, in a large measure, dependent upon the sound and orderly development of the southwestern Illinois metropolitan and regional counties area. In order to provide for such development it is essential that sound, comprehensive, general and functional plans for such area be devised to guide and coordinate the development of adequate air and water resources, quality and supply; public utility distribution system or systems; storm water and sewage disposal; surface drainage control and flood abatement; integrated air, water, rail and highway transportation; the orderly arrangements of land for residential, commercial, industrial, public and other purposes; local municipal and governmental services; the provision of social services; stimulation of economic development; improvement of environmental quality, urban esthetics and civic design; and it may be equally essential that any such plans be amended or changed from time to time in the light of future developments and scientific progress. It is also essential that there be a unit of local government available to provide the expertise, coordination and performance of administrative, management and operational functions and services for and with other units of government pursuant to voluntary, intergovernmental agreements. Therefore, it is necessary to create a unit of local government authorized to develop and adopt such comprehensive and functional plans, to amend such plans when future developments so require and to cooperate with various units of government in comprehensive planning for future growth and development.
70 ILCS 1710/2