70 ILCS 1505/26.9

For such purposes it may issue and sell or pledge to the United States Government, or any agency thereof, all or any part of the revenue bonds authorized under this law, and execute contracts and documents and do all things that may be required by the United States Government, or any agency thereof, provided that such contracts and documents do not conflict with the provisions of any ordinance authorizing and securing the payment of outstanding bonds of the Chicago Park District theretofore issued that are payable from the revenues derived from the operation of the harbor or facilities.