The compound adjective "water-powered" is a modern English formation that transparently combines two fundamental nouns. "Water," a word of ancient Proto-Indo-European lineage retained in English from its Old English and Germanic roots, signifies the specific natural element utilized. "Power," entering English via French from Latin, carries the abstract concept of force or energy. The suffix "-ed" is added to the noun-noun combination to create an adjective, following a productive English pattern for describing the means by which a machine or system is operated. The term's logic is entirely literal, directly describing technology that derives its operational energy from the kinetic or potential energy of flowing or falling water.

Structure: water (liquid) + power (energy) + ed (adjective suffix) water: Old English origin, from Proto-Germanic watōr, referring to the clear, liquid substance. Functions as a noun used attributively to specify the source of power. power: From Anglo-Norman French poeir, ultimately from Latin posse (to be able). Functions as a noun root meaning the capacity to do work or produce energy. ed: A suffix of Old English origin, used to form adjectives from nouns, meaning "having, provided with, or characterized by."