All moneys received by the City of Chicago from the sale or lease of lands granted to said city by this Act shall be credited to a fund which shall be called the Senator Dan Dougherty Harbor Fund, and all moneys expended by said city for any purpose in relation to the lands granted to said city by this Act, or in relation to the construction and maintenance of the harbor, may be charged to said fund; and said fund shall be used for no other purpose.
615 ILCS 65/6