La. Stat. tit. 25 § 219
Municipalities already owning and maintaining public libraries may consolidate the same with the parish public library, either the head library, if located in the parish seat, or a branch library, if located elsewhere in the parish, upon such terms and conditions as may be agreed upon between the governing authorities of the parish and municipality affected by ordinances regularly and legally passed and adopted evidencing such a merger and consolidation; provided that in all cases where the municipality has bound or obligated itself to maintain and support the public library, in order to keep inviolate any trust, gift or bequest for such purposes, the parish into which such municipal library is merged shall assume and become responsible for the faithful performance of the obligation and the execution of the trust assumed by the municipality.
La. R.S. § 25:219