water way; water route
Refers to a natural or man-made path for water, such as a channel, conduit, or watercourse. Often used in contexts like irrigation, drainage, or waterways for boats.
この地域には古い水の道が残っている。
Old water ways remain in this area.
Compound of 水 (mizu, 'water') + の (no, possessive particle) + 道 (michi, 'path, way'). Literally 'water's path'.