节水
jié shuǐ · HSK 7
to save water
🚰💧 节水 = 节 save/conserve + 水 water
节 means to conserve or economize (same 节 as in 节约 to economize); 水 is water. Put them together and you get conserving water. The jié in jié shuǐ is the same conserve-verb used for saving energy and money too.
节 — bamboo radical 竹 (⺮) + 即
Originally written 節, depicting a bamboo joint — the segmented node where a stalk divides. The bamboo radical ⺮ gives the meaning, while 即 supplies the sound. From 'bamboo joint' the meaning expanded to any segment, hence 'section,' 'festival' (a marked point in the year), and 'restraint' (knowing where to stop).
水 — pictograph of flowing water
水 is a pictograph depicting a stream of flowing water, with the central line representing the main current and the side strokes showing splashing droplets or ripples. In oracle bone script it was drawn even more clearly as a wavy vertical line with branches. It retains its original meaning of 'water' and also serves as a radical, often appearing in the compressed form 氵.