Upon the organization of said districts as herein provided, and as soon as said drainage commissioners have proceeded to procure the rights-of-way, either by agreement or condemnation, for ditches or canals, both main and lateral, or for the erection of levees, and the right-of-way to enter upon, alter, deepen, or improve natural drains or watercourses, they shall make an estimate of the cost, including commissioner’s fees and expenses of said proposed work, or if said estimate has been made it shall be revised and approved. Said commissioners shall file a levy certifying the amount required by them for the construction of such proposed work, and may in said levy order that so much of the benefits or betterments assessed against the lands in such district as will be necessary to defray the costs of said work, to be paid in cash; or said commissioners may in said levy order that the same be paid in not exceeding forty (40) installments, with interest on each installment at a rate of interest not to exceed six percent (6%) per annum. Or, the said commissioners may order in said levy that bonds of said district shall be issued and sold for any amount not exceeding eighty percent (80%) of the assessed value of the benefits or betterments. Said bonds shall be payable in from one (1) to forty (40) years from the date issued, with interest from the date issued at an overall maximum interest rate to maturity not greater than that allowed in Section 75-17-101, payable annually or semiannually, as the court or chancellor in vacation may direct; and it shall be lawful to attach coupons for any part of a year to the bonds maturing the first year. If bonds are thus issued and sold for an amount not exceeding eighty percent (80%) of the value of said betterments, the said commissioners may order the remaining twenty percent (20%), or any part thereof, to be paid in cash at its discretion. If the amounts levied be not sufficient to complete the work done or hereafter to be done, or if bonds are issued and sold for an amount less than eighty percent (80%) of the value of the assessed benefits and additional funds are required to complete the work or pay for work theretofore done, an additional levy may be made or an additional issue of bonds may be made, provided the additional levy, when added to the original levy, shall not exceed the amount of betterments assessed, or that the additional bond issue shall not be for an amount which, added to the original bond issue, shall exceed eighty percent (80%) of the assessed value of the betterment. Such additional levy shall be made payable in cash or in not exceeding fifteen (15) installments, each installment bearing interest at a rate not exceeding six percent (6%) per annum.

Notwithstanding the foregoing provisions of this section, bonds referred to hereinabove may be issued pursuant to the supplemental powers and authorizations conferred by the provisions of the registered bond act, being Sections 31-21-1 through 31-21-7.