https://www.amnesty.org/en/latest/campaigns/2017/11/the-occupation-of-water/

In November 1967 the Israeli authorities issued Military Order 158, which stated that Palestinians could not construct any new water installation without first obtaining a permit from the Israeli army. Since then, the extraction of water from any new source or the development of any new water infrastructure would require permits from Israel, which are near impossible to obtain. Palestinians living under Israel’s military occupation continue to suffer the devastating consequences of this order until today. They are unable to drill new water wells, install pumps or deepen existing wells, in addition to being denied access to the Jordan River and fresh water springs. Israel even controls the collection of rain water throughout most of the West Bank, and rainwater harvesting cisterns owned by Palestinian communities are often destroyed by the Israeli army. As a result, some 180 Palestinian communities in rural areas in the occupied West Bank have no access to running water, according to OCHA. Even in towns and villages which are connected to the water network, the taps often run dry.

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In Gaza, some 90-95 per cent of the water supply is contaminated and unfit for human consumption. Israel does not allow water to be transferred from the West Bank to Gaza, and Gaza’s only fresh water resource, the Coastal Aquifer, is insufficient for the needs of the population and is being increasingly depleted by over-extraction and contaminated by sewage and seawater infiltration.

The resulting disparity in access to water between Israelis and Palestinians is truly staggering. Water consumption by Israelis is at least four times that of Palestinians living in the OPT. Palestinians consume on average 73 litres of water a day per person, which is well below the World Health Organization’s (WHO) recommended daily minimum of 100 litres per capita. In many herding communities in the West Bank, the water consumption for thousands of Palestinians is as low as 20 litres per person a day, according to the United Nations Office for the Coordination of Humanitarian Affairs (OCHA). By contrast, an average Israeli consumes approximately 300 litres of water a day.