There is created a fund to be known as the "Morrison Riverfront Park Fund" of which the finance director shall be the custodian. This fund shall be administered under the direction of the park board. This fund shall be used for the receipt of donations for the Morrison Riverfront Park and for income rents from property which has been designated for the park. Disbursements from this fund shall be made only for property acquisition, development, operation, and maintenance of Morrison Riverfront Park.