drainage well vs stormwater drain

drainage well and stormwater drain both are nouns.

Word	Noun	Adjective	Verb	Adverb
drainage well	Yes	No	No	No
stormwater drain	Yes	No	No	No

As nouns, drainage well and stormwater drain are synonyms defined as:

drainage well and stormwater drain: a system of watercourses or drains for carrying off excess water

Other synonyms of drainage well include drain system, storm drain, storm sewer.

drainage well (noun)	stormwater drain (noun)
a system of watercourses or drains for carrying off excess water	a system of watercourses or drains for carrying off excess water