La. Stat. tit. 38 § 1785
No bonds issued by any district hereunder shall run for a longer period than forty years from the date thereof or bear a greater rate of interest than six per centum per annum, payable annually or semi-annually, or be sold for less than par. The governing authority issuing the bonds shall by resolution fix the form and detail of the bonds, the rate of interest, payable annually or semi-annually, within the maximum rate prescribed. The bonds shall be payable in the medium and at the place or places within or without the state fixed by resolution. All bonds hereunder shall be issued in the name of the gravity drainage district or the gravity sub-drainage district issuing the bonds, and signed on behalf of the district by the president or chief executive officer, and the secretary or clerk of district or districts under the seal of the districts. The coupons, if any, shall be signed with the printed or engraved facsimile signature of the officers. The delivery of any bonds or coupons so issued at any time thereafter shall be valid, although before the date of delivery the person signing the bonds or coupons shall cease to hold office. The governing authority issuing the bonds shall by resolution fix the time within the maximum period prescribed hereby and in the proposition submitted to the voters when the bonds shall become payable. The bonds shall be payable in annual installments beginning not more than three years after the date thereof, and the amount payable in each year shall be so fixed that when the annual interest is added to the principal amount to be paid, the total amount payable in each year shall not exceed the amount of the forced contribution or acreage tax, which may be thus funded, into bonds as provided in the above and foregoing section of this Part, after deducting from the amount of the forced contribution or acreage tax which may be thus funded, fifteen per cent of the amount thereof for cost of collection, delinquencies and contingencies.
La. R.S. § 38:1785