'non-water-related' originates from Modern English, specifically formed from the negative prefix 'non-' (from Latin 'non' meaning 'not'), the word 'water' (from Old English 'wæter' meaning 'water'), and 'related' (from Latin 'relatus' via Middle English meaning 'brought/related').

'non-water-related' was created in Modern English by compounding 'non-' + 'water' + 'related'; 'related' evolved from Latin 'referre' -> past participle 'relatus', passed through Old French/Middle English to become English 'related'.

Initially the components meant 'not' + 'water' + 'related/borne', and the compound has come to have the specific modern meaning 'not connected to or caused by water'.