45 ILCS 110/2

All property, real and personal, owned or held by the Bi-State Development Agency, and all interest income derived from any notes, bonds or other instruments in writing issued by the Bi-State Development Agency, shall possess the same status, with respect to taxation in the State of Illinois, as is now or may hereafter be possessed by property, real and personal, owned or held by cities within said State of Illinois, and by the interest income derived from notes, bonds or other instruments in writing issued by such cities.