The governing body of the borrower shall designate as depository for the “gross revenue account” and each of the special funds provided for in Section 11-81-181 a bank or trust company duly qualified and doing business within the State of Alabama. The moneys in said account and in each of the said funds shall be received and held by the respective depositories therefor in separate and special accounts as trust funds for the benefit of the borrower and the holders of the bonds and coupons as their respective interests may appear and shall be applied only for the respective purposes specified in the authorizing proceedings or any trust indenture provided for in the authorizing proceedings; provided, that the authorizing proceedings or such trust indenture may provide that any depository for said account or for the said replacement and extension fund shall not be liable for the misapplication of moneys in said account or said fund, as the case may be, if disbursed pursuant to the written order of a duly authorized officer of the borrower and without knowledge or reason to believe that such disbursement constitutes a misapplication of funds.