Section 13. The proceeds from the sale of any bonds shall be deposited with the trustee under the trust agreement to the credit of a special fund or funds to be used solely for the payment of the cost of the project and shall be disbursed in such manner and under such restrictions as may be provided in the trust agreement, except that such amount as may be provided in the trust agreement for paying the expenses of the authority prior to the time when the revenues of the project are available for such purpose may be paid over to the authority and such amount as may be provided in the trust agreement, or otherwise, for reimbursing a municipality for advances made under section nineteen may be paid over to such municipality.