La. Stat. tit. 38 § 2612
Should the district or the department of public works acquire servitude, right of way or flowage right over any property as distinguished from the fee simple title thereto such property shall not be subject to any ad valorem tax or tax of any nature by the state of Louisiana or any political subdivision thereof so long as such property is used for the purpose of the district. The provisions of this Part shall in no wise abridge the right of any individual, person, firm or corporation from whom a servitude, right of way, or flowage right may have been acquired to lease the land subject thereto for the production of oil, gas or other minerals and to produce or cause to be produced oil, gas or other minerals from such property.
La. R.S. § 38:2612