(a) Whenever the legislative body of any municipality shall determine to purchase or construct a waterworks system under the provisions of this subchapter, it shall cause an estimate to be made of the cost thereof, and shall, by ordinance, provide for the issuance of revenue bonds under the provisions of this subchapter.

(b)

(1) The ordinance shall set forth a brief description of the contemplated improvement, the estimated cost thereof, the amount and rate of interest, the time and place of payment, and other details in connection with the issuance of the bonds.

(2) The bonds shall bear interest as the ordinance authorizing their issuance may provide, payable semiannually, and shall be payable at any times and places not exceeding forty (40) years from their date as shall be prescribed in the ordinance providing for their issuance.

(3) The ordinance shall also declare that a statutory mortgage lien shall exist upon the property so to be acquired or constructed, fix the minimum rate or rates for water to be collected prior to the payment of all of the bonds, and pledge the revenues derived from the waterworks system for the purpose of paying the bonds and interest thereon.

(4) The pledge shall definitely fix and determine the amount of revenue which shall be necessary to be set apart and applied to the payment of the principal of and interest on the bonds and the proportion of the balance of the revenues and income which are to be set aside as a proper and adequate depreciation account, and the remainder shall be set aside for the reasonable and proper operation thereof.

(c) The rates to be charged for the services from the waterworks shall be sufficient to provide for the payment of interest upon all bonds and to create a sinking fund to pay the principal as and when they become due, to provide for the operation and maintenance of the system, and to provide an adequate depreciation fund.