(a) Any county of this state shall have the power and is authorized to refund its outstanding bonded indebtedness on terms the county court shall deem for the best interest of the county and to that end may issue negotiable bonds with interest coupons attached. Such refunding bonds either shall mature serially, the first principal payment to be not more than five (5) years after date, over a period of not more than forty (40) years from date thereof or shall mature on or before some fixed date not more than forty (40) years from date thereof, in which event the bonds shall provide for tender or call, or both, to be paid out of any surplus in the bond fund account.
(b) The county judge of the county may exchange refunding bonds for outstanding bonds of the county.
(c) The refunding bonds shall not be issued in a greater amount than the face value of the outstanding bonds then being refunded, and in no event shall the refunding bond bear a greater rate of interest than that borne by the bond for which it is exchanged.
(d) The new bonds shall bear the original signature of the county judge, under the seal of the county.
(e) This subchapter is intended to authorize only the refunding of valid, outstanding county funding, courthouse, or jail bonds.