190.017 Trust agreements.—Any issue of bonds shall be secured by a trust agreement by and between the district and a corporate trustee or trustees, which may be any trust company or bank having the powers of a trust company within or without the state. The resolution authorizing the issuance of the bonds or such trust agreement may pledge the revenues to be received from any projects of the district and may contain such provisions for protecting and enforcing the rights and remedies of the bondholders as the board may approve, including, without limitation, covenants setting forth the duties of the district in relation to: the acquisition, construction, reconstruction, improvement, maintenance, repair, operation, and insurance of any projects; the fixing and revising of the rates, fees, and charges; and the custody, safeguarding, and application of all moneys and for the employment of consulting engineers in connection with such acquisition, construction, reconstruction, improvement, maintenance, repair, or operation. It shall be lawful for any bank or trust company within or without the state which may act as a depository of the proceeds of bonds or of revenues to furnish such indemnifying bonds or to pledge such securities as may be required by the district. Such resolution or trust agreement may set forth the rights and remedies of the bondholders and of the trustee, if any, and may restrict the individual right of action by bondholders. The board may provide for the payment of proceeds of the sale of the bonds and the revenues of any project to such officer, board, or depository as it may designate for the custody thereof and may provide for the method of disbursement thereof with such safeguards and restrictions as it may determine. All expenses incurred in carrying out the provisions of such resolution or trust agreement may be treated as part of the cost of operation of the project to which such trust agreement pertains.