10 ILCS 5/11-1
In counties not under township organization, the election precincts shall remain as now established until changed by the Board of County Commissioners, but said County Board may, from time to time, change the boundaries of election precincts and establish new ones. In counties under township organization, each town shall constitute at least one election precinct. Insofar as is practicable, each precinct shall be situated within a single congressional, legislative and representative district and within a single municipal ward. In order to situate each precinct within a single district or ward, the County Board shall change the boundaries of election precincts after each decennial census as soon as is practicable following the completion of congressional and legislative redistricting.
At any consolidated primary or consolidated election at which municipal officers are to be elected, and at any emergency referendum at which a public question relating to a municipality is to be voted on, notwithstanding any other provision of this Code, the election authority shall establish a polling place within such municipality upon the request of the municipal council or board of trustees at least 60 days before the election and provided that the municipality provides a suitable polling place. To accomplish this purpose, the election authority may establish an election precinct constituting a single municipality of under 500 population for all elections, notwithstanding the minimum precinct size otherwise specified herein.
Notwithstanding the above, when there are not more than 50 registered voters in a precinct who are entitled to vote in a local government or school district election, the election authority having jurisdiction over the precinct is authorized to reassign such voters to one or more polling places in adjacent precincts, within or without the election authority's jurisdiction, for that election. For the purposes of such local government or school district election only, the votes of the reassigned voters shall be tallied and canvassed as votes from the precinct of the polling place to which such voters have been reassigned. The election authority having jurisdiction over the precinct shall approve all administrative and polling place procedures. Such procedures shall take into account voter convenience, and ensure that the integrity of the election process is maintained and that the secrecy of the ballot is not violated.
Except in the event of a fire, flood or total loss of heat in a place fixed or established by any election authority pursuant to this Section as a polling place for an election, no election authority shall change the location of a polling place so established for any precinct after notice of the place of holding the election for that precinct has been given as required under Article 12 unless the election authority notifies all registered voters in the precinct of the change in location by first class mail in sufficient time for such notice to be received by the registered voters in the precinct at least one day prior to the date of the election.
The provisions of this Section apply to all precincts, including those where voting machines or electronic voting systems are used.
If, as a result of the redistricting of legislative, representative, or congressional districts following a decennial census, there exists a census block with only one voter that is the only census block in a precinct that is in a legislative, representative, or congressional district, then the county board, at any meeting of the county board, may change the precinct boundaries so that the census block is within a precinct that has more than one voter in the legislative, representative, or congressional district.
10 ILCS 5/11-1