If the board, in its resolution, determines that the refunding bonds may be sold for an amount less than their aggregate par value, and that it is necessary or advisable that an amount be made available for the payment of interest upon the refunding bonds from the date of the sale thereof to the date of maturity of the bonds to be refunded out of the proceeds of the sale, the resolution of sale shall direct that a warrant be forthwith drawn against the general or maintenance fund of the district in favor of the county treasurer as trustee of the bond fund and delivered to the county treasurer.