noun
water for a specific use; irrigation water; firefighting water; city or stored service water
A general noun for water supplied, set aside, or used for a practical purpose. Common in compounds specifying the purpose, especially agriculture, firefighting, urban supply, or stored water.
農家は川から田んぼに用水を引いている。
The farmers draw irrigation water from the river into the rice fields.
校庭の隅に防火用水のタンクがある。
There is a firefighting water tank in the corner of the schoolyard.
夏になると都市用水の需要が増える。
Demand for city water increases in summer.