(a) Consolidated systems may borrow money to pay and discharge any outstanding bond issues and indebtedness of the districts joining in the consolidations and may borrow money also for improvement, enlargement, and betterment of the facilities of the consolidated systems.
(b) To accomplish these purposes, the consolidated systems may issue negotiable coupon bonds or certificates of indebtedness evidencing the money so borrowed, to:
(1) Be secured solely by a pledge of the net revenues derived from the operation of the facilities;
(2) Bear interest not to exceed six percent (6%) per annum;
(3) Mature at such times and places as the issuer shall decide best, but in no event to mature later than forty (40) years after date of issue;
(4) Be issued with such terms of payment, call provisions, and interest rates as the issuer may decide best; and
(5) Be sold with the privilege of conversion to lower interest rates.