La. Stat. tit. 38 § 1902
The governing authority of any gravity drainage or gravity sub-drainage district when authorized to do so by a vote of the resident property tax payers qualified to vote in the drainage district or sub-drainage district, of a majority, both in number and amount, may levy and collect a tax not to exceed five mills on the dollar upon all property subject to taxation in the drainage district or sub-drainage district and to run for a period not to exceed ten years. The tax shall be used for the purpose of maintaining, constructing, and improving drainage works within the territorial limits of the drainage district or sub-drainage district. The tax shall not be funded into bonds but shall be collected annually by the tax collector of the parish in which the drainage district or sub-drainage district is located, for the use and benefit of the drainage district or sub-drainage district.
La. R.S. § 38:1902