Legal Aspects of Exploitation of Hirmand Border River by Iran and Afghanistan

Since the ownership of border rivers is not entirely in the hands of a certain country, exploiting and employing these rivers have been always a controversial issue within many governments. Hirmand Border River which originates from Kabul West Mountain and pours into Hamoun pond after traveling 1050 Km has been of the legal issue between Iran and Afghanistan since assigning the Paris agreement in 1857.
This paper seeks to answer this question that what are the legal aspects of exploiting Hirmand River, and what principles dominate the international rivers in terms of international law? Thus, based on different approaches to the dominant lawful regime on international rivers, the present paper based on statutory rules, practice and votes of international courts, and government approachesaims to recognize the dominating principles on international rivers and apply them to Hirmand River. Ultimately, this study suggests that the international law principles of international rivers have accepted “the principle of limited territorial sovereignty” on international rivers. And in accordance with international laws principles, rivers whose basins are located in another country, the upstream country cannot change or drift the route of that river or any other act which does harm to downstream countries.