IMPLICATIONS OF THE INDUS WATER KISHENGANGA ARBITRATION FOR THE INTERNATIONAL LAW OF WATERCOURSES AND THE ENVIRONMENT JASMINE MOUSSA* Abstract On 19 February 2013, a Permanent Court of Arbitration (PCA)- administered Court of Arbitration issued a Partial Award on the dispute between Pakistan and India regarding the use of the waters of the Kishenganga/Neelum, a tributary of the Indus system of rivers. This article examines the tribunal’s decision, which was mainly limited to interpreting the 1960 Indus Water Treaty (IWT), and its contribution to international environmental law and the law of non-navigational uses of international watercourses. After briefly discussing the dispute’s factual context and procedural history, the article critiques the tribunal’s methodology, which was based on an inconsistent application of the principles of treaty interpretation. The Award’s contribution is therefore mixed: despite its almost complete disregard for the principle of ‘equality of right’, it has contributed to clarifying the criteria for determining ‘existing uses’ of a watercourse and reaffirmed both the substantive obligation to refrain from causing transboundary harm and the procedural duty to carry out an Environmental Impact Assessment under international environmental law. Keywords: Indus Waters Kishenganga Arbitration, international environmental law, law of non-navigational uses of international watercourses, Permanent Court of Arbitration, river damming and diversion, treaty interpretation, no harm principle. I. INTRODUCTION In May 2010, Pakistan instituted proceedings against India in the matter of the Indus Water Kishenganga under the dispute settlement procedure of the 1960 Indus Water Treaty (IWT). 1 The dispute related to India’s construction of the Kishenganga Hydro- Electric Project (KHEP) and the subsequent diversion of the Kishenganga/Neelum River such that it would reach Pakistan via a different tributary. Pakistan objected to * Assistant Professor of Law, American University in Cairo, jasmine.moussa@aucegypt.edu. 1 Indus Water Kishenganga Arbitration (Pakistan v India) (Partial Award) (Feb 2013) <http:// www.pca-cpa.org/showpage.asp?pag_id=1392> [4]; art IX (5) and Annex G of the Indus Water Treaty (India, Pakistan and the World Bank) (signed 19 September 1960, entered into force (retrospectively) 1 April 1960) 419 UNTS 126. See also Y Andreeva, M Brunetti and G Lemenez, ‘International Courts’ (2012) 46(1) IntlLaw 129, 139; Indus Water Kishenganga Arbitration (Order on Interim Measures) (Sept 2011) [4]. [ICLQ vol 64, July 2015 pp 697–715] doi:10.1017/S0020589315000287