If bonds have been issued for any construction subdistrict secured entirely or partially by the right to levy an assessment as provided by KRS 220.571 to 220.583, 220.591 to 220.601, and 220.607 to 220.613 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 220.577.
KRS 220.581