65 ILCS 5/11-80-21

The corporate authorities by condemnation or otherwise may extend any street or alley over or across, or may construct any sewer under any railroad track, or through the right-of-way or land of any railroad company. Where no compensation is made to the railroad company, however, the municipality shall restore the railroad track, right-of-way, or land so that its usefulness will not be impaired more than is reasonably necessary.