Geneva Convention 1977 Protocols:
“It is prohibited to attack, destroy, remove or render useless objects indispensable to the survival of the civilian population, such as... drinking #water installations & supplies and irrigation works... for any other motive.”
https://www.tribuneindia.com/news/world/blatant-and-desperate-crime-irans-fm-condemns-us-attack-on-qeshms-freshwater-desalination-plant-warns-of-grave-consequences/