The board may provide for the payment of the interest becoming due and payment on the principal of revenue bonds prior to and during the period of actual construction of the project for which the bonds are issued and for the period specified in the indenture for the issuance of the bonds, which period shall not exceed two years after the completion of construction and for the payment of all costs and expenses of administration during a period of one year after the completion of construction of the project out of the bond fund or enterprise fund as the need therefor may arise and moneys in the bond fund or enterprise fund are hereby made available for such purposes.