If heavy rains change the course of a river and five feet of land are added to a property abutting the river as a result of the redirection, the property owner acquires rights to the added land by?

Question:  If heavy rains change the course of a river and five feet of land are added to a property abutting the river as a result of the redirection, the property owner acquires rights to the added land by

Answer:  Accession