If bonds have been issued for any construction subdistrict secured entirely or partially by the right to levy an assessment as provided by KRS 76.251 to 76.257, 76.261 to 76.267 and 76.271 to 76.273 and such bonds are redeemed prior to maturity, bonds to refund same may be issued secured solely by the revenue of said system in the manner provided in KRS 76.254.
KRS 76.256