Water Safety In Israel
"Tap water in Israel is good for drinking.
The potability of natural water sources is unknown and shouldn't be counted upon. Some areas are suspected of contamination even if the water looks and smells fine.
There usually aren't any water taps near hiking trails or even in campgrounds, except in paid campsites.
If you're unused to the weather in Israel, you should consult experienced hikers to find out how much water you should carry. If there's no one you can ask, use the following numbers; they may look like too much for travellers from more cool countries, but there can be a huge difference on that account. Remember that they only refer to drinking water, not including cooking and other uses.
In cold days or when most of the walk is in the shade, carry at least 3 L per person for a whole day.
In cool days of winter, fall and spring, which aren't really cold, carry 4.5 L.
In warm (not extremely hot) days on easy and moderate trails, carry 6 L.
Hardcore hiking in the desert at summer really shouldn't be done until you know how well you can handle that. If you do decide to do that, carry at least 7.5 L of water until you're sure you know how much you drink; it's pretty likely you really will drink it all up."