20 ILCS 1705/8
To control the admission and transfer of recipients or other persons in the facilities and programs of the Department. The Department may divide the State into districts for the purpose of regulating the admission of recipients to mental health facilities for persons with mental illness. The Department may change the boundaries of the districts, from time to time, as may be necessary or expedient. Whenever such division or regulation shall have been made, the Department shall forthwith make and sign a report to that effect, designating the boundaries of and the counties included within each district and the number of recipients apportioned to each mental health facility and file the same with the Secretary of State, and send a copy thereof to the director of each mental health facility and to the circuit court of each county, and to the circuit clerk of each county in the State, to be filed in his office, and thereafter the State shall be divided into such districts. Whenever any change in such classification or regulation is made thereafter, a like report shall be made and filed, and a copy thereof sent to the circuit court of each county and to the circuit clerks of all counties affected by such change, as well as to the facility director of the respective State mental health facilities.
20 ILCS 1705/8