(a) In order to meet preliminary expenses and to do the work, the board may issue the negotiable notes or bonds of the district signed by the members of the board and bearing a rate or rates of interest approved by the board and may pledge and mortgage all assessments for the payment thereof.
(b) It may also issue to the contractors who do the work negotiable evidences of debt-bearing interest at a rate or rates provided in the resolution authorizing their issuance and secure the negotiable evidences of debt in the same manner as set out in subsection (a) of this section.
(c) No bonds issued under the terms of this chapter shall run for more than thirty (30) years, and all issues of bonds may be divided so that a portion thereof may mature each year as the assessments are collected or they may all be made payable at the same time, with proper provision for a sinking fund.
(d) The bonds shall not be sold for less than par without the unanimous vote of the board.