Drainage
Drain, Gutter
A reject water gutter is drainage, which we also call a drain, or a gutter. This word covers both the drain in your sink or bathtub, and roadside gutters.
はいすいこう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
お風呂の排水溝が髪の毛で詰まっちゃったみたいなの。
It looks like hair clogged the drain for the bathtub.