620 ILCS 25/11
It is hereby found that an airport hazard endangers the lives and property of users of the airport and of occupants of land in its vicinity, and also, if of the obstruction type, in effect reduces the size of the area available for the landing, taking-off and maneuvering of aircraft, thus tending to destroy or impair the utility of the airport and the public investment therein. Accordingly, it is hereby declared: (a) that the creation or establishment of an airport hazard is a public nuisance and an injury to the community served by the airport in question; (b) that it is therefore necessary in the interest of the public health, public safety, and general welfare that the creation or establishment of airport hazards be prevented; and (c) that this should be accomplished, to the extent legally possible, by exercise of the police power, without compensation. It is further declared that both the prevention of the creation or establishment of airport hazards and the elimination, removal, alteration, mitigation, or marking and lighting of existing airport hazards are public purposes for which the State and its political subdivisions may raise and expend public funds and acquire land or property interests therein.
620 ILCS 25/11