Amnesty International is accusing Israel of pumping disproportionate amounts of drinking water from an aquifer it controls in the West Bank, depriving local Palestinians of their fair share.
The London-based human rights group also said in a report to be released Tuesday, that Israel has blocked infrastructure projects that would improve existing water supplies to Palestinians — both in the West Bank and those living in the Gaza Strip.
"This scarcity has affected every walk of life for Palestinians," Amnesty's researcher on Israel, Donatella Rovera, told The Associated Press in an interview Monday, ahead of the report's release. "A greater amount of water has to be granted to them."
Israeli officials deny the accusations.
Water is a major point of contention between Israelis and Palestinians and is considered an issue that must be resolved before the two sides could make peace.
The issue is further compounded by the split in Palestinian territories, with the moderate Fatah movement governing the West Bank, while the militant Hamas rules the coastal Gaza Strip.
Israelis use more than four times the amount of water per person on average than do Palestinians, whose consumption falls far below the minimum amount recommended by the World Health Organization, the report said.
Since Hamas seized control of the coastal territory in 2007, Gaza's long-standing problems with sewage and water sanitation facilities have deteriorated, Rovera said. During Israel's offensive in Gaza last year, water and sewage pipes suffered severe damage.
Rovera said the water situation in Gaza had reached a "crisis point," with 90 percent to 95 percent of the water supply contaminated and unfit for human consumption.
An Israeli blockade of Gaza has halted any repairs to the strip's overburdened sewage and water networks, preventing materials and equipment to repair the infrastructure from getting in, Rovera said.