water pipe, gutter, downspout, conduit
樋 centers on a channel that directs water: a pipe, gutter, downspout, or conduit. All meanings share the idea of guiding flowing water along a set path.
樋 combines 木 (wood) with 通 (pass through), suggesting a wooden channel through which water passes. This is a straightforward phono-semantic compound where 通 likely contributes the sound トウ.
A wooden 木 channel that lets water pass through 通: picture a wooden gutter or downspout guiding rainwater from the roof to the ground.
For トウ, imagine a toe stuck in a water pipe: toe -> トウ, and the water flows through the wooden conduit around it.
trough; gutter; water pipe; flume; chute
covered drain
elbow; gooseneck; rainspout
wooden water pipe; wooden flume
gargoyle
(water) spring
toilet
downpipe; drainspout; water pipe
rain gutter; roof gutter; eaves gutter
rain chain (hanging from a gutter and functioning as downspout, often made of ornamental cups)
drainspout; rain gutter