drainpipe vs sewerage

drainpipe and sewerage both are nouns.

Word	Noun	Adjective	Verb	Adverb
drainpipe	Yes	No	No	No
sewerage	Yes	No	No	No

As nouns, sewerage is a hyponym of drainpipe; that is, sewerage is a word with a more specific, narrower meaning than drainpipe:

Other hyponyms of drainpipe include culvert, scupper, cloaca, sewer, soil pipe, trap.

drainpipe (noun)	sewerage (noun)
a pipe through which liquid is carried away	a waste pipe that carries away sewage or surface water
	waste matter carried away in sewers or drains