The authority said that during a trial, its teams restored flows to communities hooked up to the water main, encompassing nearly one million people living or displaced in Al-Maghazi, Al-Bureij, Nuseirat and Deir Al-Balah.

Almost all Gazans have been displaced during the nearly two years of war in the Palestinian territory, increasing the population density in central Gaza, which has been less affected by air strikes.

The repairs on the water main took time, the Water Authority said, because of military activity and the presence of Israeli forces, and had to be done in coordination with Israeli authorities.

The water line is supplied by Mekorot, the state-owned Israeli company that supplies 22 percent of the water in Gaza and the West Bank, according to the Palestinian statistics office, with the Ramallah-based Palestinian Authority footing the bill.

The Palestinian Authority, which oversees the Water Authority, still operates in certain civilian matters in the Gaza Strip, even though control of the territory was seized by its rival Hamas in 2007.

A UN source compared the task of repairing Gaza's water lines to the task of Greek mythology character Sisyphus, who must push a boulder up a hill every day, only for it to roll back down.

"We repair, but we don't know when it will be destroyed again," the source said.

Repairing central Gaza's water main will not bring back water to all of the area, as humanitarian sources estimate that 80 percent of the distribution network is damaged, and leaks are frequent.

The war aggravated the pre-existing water crisis in Gaza, with water pumped from a shrinking aquifer often coming out brackish and unsafe for human consumption.

The UN-led WASH Cluster, a group of humanitarian organisations working on water and hygiene issues in Gaza, says that most water pipes have been damaged during military offensives, and that many Gazans living under air strikes or in displacement camps have nothing to store water with.

For displaced Gazans living in makeshift shelters and camps in the areas near Gaza's coast, often the only source of water is temporary distribution sites set up by humanitarian groups, or water trucks.

The war in Gaza was triggered by Hamas's October 7, 2023 attack on Israel that resulted in the deaths of 1,219 people, mostly civilians, according to an AFP tally of Israeli official figures.

Israel's retaliatory offensive has killed at least 66,288 Palestinians, according to health ministry figures in the Hamas-run territory that the United Nations considers reliable.