tidewater river vs tidewater stream

tidewater river and tidewater stream both are nouns.

Word	Noun	Adjective	Verb	Adverb
tidewater river	Yes	No	No	No
tidewater stream	Yes	No	No	No

As nouns, tidewater river and tidewater stream are synonyms defined as:

tidewater river and tidewater stream: a stream in which the effects of the tide extend far upstream

Other synonyms of tidewater river include tidal river, tidal stream.

tidewater river (noun)	tidewater stream (noun)
a stream in which the effects of the tide extend far upstream	a stream in which the effects of the tide extend far upstream