La. Stat. tit. 33 § 3675.6
Upon the receipt of the certified statement or report of the engineer as provided for in R.S. 33:3675.5, the governing authority shall adopt an ordinance levying a local or special assessment on each lot or parcel of real estate in the area involved in proportion that its area bears to the total area, as herein provided. The total of all such local or special assessments shall represent the total cost of the improvements, including street intersections, engineers' fees, and all other costs incidental to the work. The amounts assessed in the ordinance shall be due and collectible immediately on its passage, and, if not paid within thirty days from the date of the adoption of the ordinance, it will be conclusively presumed that any property owner whose property is affected thereby, exercises the right and option, which is hereby authorized, to pay the amount due in equal annual installments bearing interest at a rate not exceeding six per centum (6%) per annum, payable annually, and extending over a period not exceeding fifteen years, as provided for in the ordinance levying the local or special assessments. The first installment shall become due on December 31 of the then current year and annually thereafter. The local or special assessments may be carried on the tax roll of the municipality and collected at the same time as taxes. The failure to pay any installments and the interest thereon when due, shall ipso facto cause all other installments and the interest thereon to become due and payable and the municipality shall within thirty days from the date of such default, proceed against the property for the collection of the total amount due thereon, including interest, plus ten (10%) per cent additional on principal and interest unpaid as attorney's fees. A certified copy of the ordinance levying the local or special assessments on the real estate shall be filed with the clerk of court in the parish in which the municipality is situated, who shall forthwith record the same in the mortgage records of the parish, and when so filed and recorded, shall operate as a lien and privilege against all real estate therein assessed. The payments made in cash shall be expended for no other purpose than for the payment of the cost of the improvements.
La. R.S. § 33:3675.6