Iowa Code § 386.13
A city may apply moneys in the operation fund of the district to prepay parking fees at any city parking facility located in or used in conjunction with the district but only after notice and hearing as required by section 386.6. The authority to prepay such fees shall exist only for the period of time set out in the notice to owners and in the resolution of the council authorizing the application of funds for that purpose. Upon the application of sufficient amounts of prepaid fees, the city need not charge individual users of the parking facility. Before adopting a resolution authorizing the application of funds for such purpose, the council must find that the application will further the purposes of the district, including but not limited to increasing the commercial activity in the district.
Iowa Code § 386.13