Iowa Code § 28J.25
All revenues, funds, properties, and assets acquired by the port authority under this chapter, whether as proceeds from the sale of port authority revenue bonds, pledge orders, or as revenues, shall be held in trust for the purposes of carrying out the port authority's powers and duties, shall be used and reused as provided in this chapter, and shall at no time be part of other public funds. Such funds, except as otherwise provided in a resolution authorizing port authority revenue bonds or in a trust agreement securing the same, or except when invested pursuant to section 28J.26, shall be kept in depositories selected by the port authority in the manner provided in chapter 12C, and the deposits shall be secured as provided in that chapter. The resolution authorizing the issuance of revenue bonds or pledge orders, or the trust agreement securing such bonds or pledge orders, shall provide that any officer to whom, or any bank or trust company to which, such moneys are paid shall act as trustee of such moneys and hold and apply them for the purposes hereof, subject to such conditions as this chapter and such resolution or trust agreement provide.
Iowa Code § 28J.25
2005 Acts, ch 150, § 113