Hundreds of Gaza's water and sanitation facilities have been damaged or destroyed since Israel began military action against Hamas, satellite analysis by BBC Verify has found.
Damage to a major supplies depot has also severely disrupted repairs.
The lack of clean water and flows of untreated sewage pose a serious threat to health, say aid agencies.
The Israel Defense Forces told the BBC that Hamas cynically exploits civilian infrastructure for terror purposes.
The destruction comes despite Israel's duty to protect critical infrastructure under the rules of war, unless there is evidence sites are being used for military reasons, say human rights lawyers.