La. Civ. Code art. 504
Current with operative changes from the 2024 Third Special Legislative Session
When a navigable river or stream abandons its bed and opens a new one, the owners of the land on which the new bed is located shall take by way of indemnification the abandoned bed, each in proportion to the quantity of land that he lost.
If the river returns to the old bed, each shall take his former land.
La. C.C. § 504