CNN  — 

United Nations officials are warning that millions of Palestinians face dehydration and are at risk of waterborne disease in an escalating water crisis as Israel continues to withhold essential supplies from Gaza in the wake of Hamas’ Oct. 7 attack.

The last functioning desalination plant shut down on Sunday due to lack of fuel, as did the last functioning wastewater treatment plant, the UN reported. Israel turned on one line of water in the south of Gaza for three hours on Monday, but the UN relief agency in Gaza said it served only 14% of the population.

With the exception of people in Khan Younis, Gaza, where water was turned back on, the UN estimated on Monday that average water consumption in the strip has dropped to three liters per person per day.

The World Health Organization recommends that people have access to a minimum range of 50 to 100 liters of water a day per person. For years, Gazans have not had access to more than the minimum, according to the Palestinian Water Authority.

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Gaza’s remaining entry point, the Rafah crossing, is closed and aid is unable to get to millions of people. Dozens of trucks are on the Egyptian border, waiting to enter. The US has been pressuring Egypt to create a humanitarian corridor for Gazan civilians and foreigners. Egypt has said there has been no progress in efforts to open it and Israel has denied there were any arrangements for its opening.

Even before the current war, residents of Gaza faced a severe water shortage. Most of their water comes from the Coastal Aquifer, which suffers from over-extraction, saltwater intrusion and sewage infiltration and is on the brink of collapse. This water is salty and brackish and as much as 96% of it is not fit for human consumption.

Some people have resorted to drinking seawater, which is highly saline and contaminated with untreated sewage, a WHO spokesperson told CNN.

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Fuel shortages and dangerous airstrikes have also led most water trucks to suspend operations, and bottled water is severely limited and unaffordable, according to the UN. Most people currently get drinking water from private vendors who run small desalination facilities that are mostly powered by solar energy.

In 2021, about 90% of Gaza’s water came from groundwater wells, according to the Palestinian Water Authority. The remaining 10% of the water supply comes from the desalination plants or is purchased from Israel’s national water company, Mekorot.