sentences:  The middle Zambezi ends where the river enters Lake Cahora Bassa (also spelled Cabora Bassa).Formerly the site of dangerous rapids known as Kebrabassa, the lake was created in 1974 by the construction of the Cahora Bassa Dam.The lower Zambezi's 650 km from Cahora Bassa to the Indian Ocean is navigable, although the river is shallow in many places during the dry season.