The 179-page report says that "since October 2023, Israeli authorities have deliberately obstructed Palestinians' access to the adequate amount of water required for survival in the Gaza Strip".
It says Israel intentionally damaged infrastructure, including solar panels powering treatment plants, a reservoir, and a spare parts warehouse, while also blocking fuel for generators.
It says Israel also cut electricity supplies, attacked repair workers and blocked the entry into Gaza of repair materials.
"This isn't just negligence," said HRW executive director Tirana Hassan. "It is a calculated policy of deprivation that has led to the deaths of thousands from dehydration and disease that is nothing short of the crime against humanity of extermination, and an act of genocide."
Human Rights Watch accuses Israel of acts of genocide in Gaza over water access. By Raffi Berg, BBC