The rights and obligations of States concerning their shared transboundary groundwates are not fully understood. The primary reasons for this are the complex characteristics and behaviours of groundwater, and the lack of full understanding of its interconnection with the surrounding environment. Consequently, States appear to be reluctant in concluding legally binding arrangements that specifically address this topic. This complexity is further intensified under difficult political situations, whereby the Parties sharing groundwater are unable to foresee the benefits of cooperation concerning this resource. This thesis represents an inquiry into the rules and principles governing the utilization of shared transboundary groundwater, and how cooperative frameworks can be initiated implemented, in the complex political context of the Mountain Aquifer shared between Israel and Palestine. The main objective of this thesis is to achieve an integrative mutually beneficial arrangement in the case of the Mountain Aquifer, based on lessons learnt from international law. The proposal for approaching the problem within the Palestinian-Israeli context is to progressively establish a solid basis for long-term sustainable arrangements. The progressive approach starts with a non-binding flexible arrangement that can serve the short-term need, which gradually builds up into a final legally binding arrangement based on international law.