No. Israel supplies water via pipes. There is not enough water in the region and Israel has turned water purification/desalination into a large scale operation, yet it provides it to Gaza despite being under attack from Hamas for decades (rockets, suicide bombers etc., 7/10 etc.).

Some stupid Israeli politicians tried to stop that water supply claiming that it's insane to provide your enemy with resources during war (Israel also supplies electricity and fuel to Gaza, both are used in the Hamas tunnels to pump in air). Unfortunately, this stupidity by the current government became the basis of the stuff you're repeating.