This was one of the big problems with Oslo. It left a lot of things up in the air but provided a basic framework for a future division of the Isreal and Palestine. The biggest failure wasn't Israel or Palestine but rather it was the assasination of Rabin which basically crushed any sort of progress. Combined with the rise of Netanyahu and Likud, the best chance at peace disappeared. While future questions like the right of return and Jerusalem weren't answered in Oslo, Oslo did explicity ban future settlements which Israel plainly ignored. Also, the Y river agreement with Netanyahu called for phased pullouts of Israel from Palestinian territory which were never truly fulfilled despite years of relative peace at the time. Both sides screwed up majorly but don't pretend that Israel has been a servent of the law and its agreements because it has done plenty to violate accords to which it agreed to.
Some experts have been saying for a few years now that future conflicts would be fought over water more so than anything else.
The water issue is not a tough one to solve. Israel allows Palestine access to the lower Jordan River. Problem solved.
They need at least partial control of it, as well the aquifers. They also need access to the farmland. It would be easy if Israel would do it. But they haven't been willing to so far.
