In case the proceeds of the original tax levy made under the provisions of La. Rev. Stat. 38:1631 are not sufficient to pay the principal and interest of all bonds issued, then the board of commissioners shall make any additional levy or levies upon benefits assessed necessary for this purpose.  Under no circumstances shall any tax levies be made that will in any manner or to any extent impair the security of the bonds or the funds available for the payment of the principal and interest of the bonds.