Joshua 17:9

And the coast descended unto the river Kanah, southward of the river: these cities of Ephraim are among the cities of Manasseh: the coast of Manasseh also was on the north side of the river, and the outgoings of it were at the sea:

Cross-reference

Joshua 16:8 also mentions the brook Kanah as Ephraim's western border, matching this boundary.

Joshua 16:9 explains that Ephraim had towns within Manasseh, which this verse details as cities south of the brook.