Executive Summary
Overview
More than 286 international river basins and hundreds of shared aquifers span national borders. Nearly half of the world’s population depends on cooperative transboundary water management to ensure access to safe water, food security, and ecological wellbeing. Yet the legal architecture supporting water governance is under acute stress. Drawing on the Convention on the Law of the Non-Navigational Uses of International Watercourses, 1997 (UN Watercourses Convention), the Convention on the Protection and Use of Transboundary Watercourses and International Lakes, 1992 (UNECE Water Convention), General Comment No. 15 of the Committee on Economic, Social and Cultural Rights (CESCR) interpreting the International Covenant on Economic, Social and Cultural Rights (ICESCR), and jurisprudence of international courts and tribunals, this brief argues that the human right to water is not merely aspirational ideal; it constitutes binding constraints on sovereign water use with concrete implications for treaty design, dispute resolution, and state accountability. To this end, this brief provides policy recommendations for states, international organizations, and civil society to operationalize this obligation in treaty frameworks, institutional design, and climate adaptation planning.
The human right to water and sanitation is recognised in both international human rights law and international water law. General Comment No. 15 expressly recognizes the core obligations associated with the right to water as non-derogable. The right to water fundamentally reframes the issues at stake in transboundary water disputes. The central question is no longer limited to how sovereign states allocate a shared watercourse, but also whether they are fulfilling their obligations to the populations whose survival depends on it.
Policy Recommendations
For States:
- Expand Treaty Ratification and Harmonization: States should ratify both the UN Watercourses Convention and the UNECE Water Convention. Ratification would support the harmonization of basin-specific legal frameworks with the Conventions’ guiding principles.
- Integrate Climate Adaptation into Governance Frameworks: Transboundary water treaties and basin commission mandates should explicitly incorporate climate change adaptation obligations, including joint monitoring, hydrological data sharing, and scenario planning.
- Operationalize Obligations Relating to the Human Right to Water: States should incorporate General Comment No. 15’s non-derogable core obligations into domestic law and bilateral/multilateral water agreements.
For Pakistan
- Ratify and Champion the UN Watercourses Convention: Pakistan has not ratified the UN Watercourses Convention, which weakens its ability to invoke the Convention’s equitable utilization and no-harm provisions in international forums. Ratification would not only strengthen Pakistan’s legal standing in future disputes but would also signal commitment to a rules-based international order. This would carry diplomatic weight when seeking third-party support in disputes with more powerful upstream neighbors.
- Ground Water Claims within Human Rights Law: Pakistan should reframe its water security arguments, not only in terms of treaty rights, but in terms of the human right to water under General Comment No. 15. Given that disruptions to Indus flows directly threaten the water and food security of tens of millions of Pakistanis, framing upstream interference as a violation of non-derogable human rights obligations shifts the moral and legal weight of the dispute.
- Invest in Domestic Water Governance and Efficiency: Pakistan’s position in any transboundary dispute is weakened by its inefficient water management. Strengthening domestic governance will reduce Pakistan’s overall vulnerability to upstream variability.
- Build Regional and Multilateral Coalitions: Pakistan is not the only riparian that faces downstream vulnerability. Pakistan should actively cultivate coalitions among downstream states to collectively advocate for stricter compliance with principles of international water law and international human rights law.
The Human Right to Water in Transboundary Water Governance
Introduction
More than 40% of the global population resides within transboundary river basins, while over 2.8 billion people rely directly on shared international watercourses for drinking water, agriculture, and their livelihoods.[1] The governance of these shared water resources has long been marked by disputes between upstream and downstream states over development objectives, environmental protection, and competing conceptions of sovereignty.
Contemporary pressures such as climate change, population growth, rapid infrastructure development, and intensifying geopolitical tensions, are straining even the most durable water-sharing agreements. In early 2025, India suspended the Indus Waters Treaty, 1960 (IWT) with Pakistan, threatening the agricultural and food security of over 200 million Pakistanis. Similarly, in the Nile Basin, Ethiopia’s Grand Ethiopian Renaissance Dam (“GERD”) continues to generate acute tensions with Egypt and Sudan. In the Mekong River Basin, upstream dam construction by China has altered hydrological flows that downstream communities rely upon for their livelihoods and water security.[2]
These crises reflect not only political shortcomings but also deficiencies in the legal framework. A key element in addressing this gap is the concept of non-derogable environmental obligations- duties from which states cannot absolve themselves through treaties, domestic legislation, or political circumstances. This works alongside the growing recognition that certain forms of severe and irreversible environmental harm may amount to violations of peremptory norms of international law.
In each of these situations, an exclusive focus on states often obscures the interests of the individuals and communities affected, as those who lose access to safe water when a river is dammed, diverted, or polluted are rarely the parties to the dispute. Therefore, this brief addresses transboundary water governance through the lens of the human right to water. The human right to water, now anchored in both international human rights law and international water law, fundamentally changes the nature of a transboundary water dispute. Rather than merely concerning the allocation of shared water resources between states, the dispute becomes one of whether states are fulfilling their obligations to protect the rights and interests of the populations that depend on those waters for their survival.
Non-Derogable Obligations in International Water Law
In international law, a non-derogable obligation is one from which states cannot deviate, regardless of consent, emergency, or any competing agreement. The concept originates primarily in human rights law but has progressively extended into environmental and humanitarian law.[3]
The most robust form of non-derogability is expressed through jus cogens, or peremptory norms. Article 53 of the Vienna Convention on the Law of Treaties (1969) provides that any treaty which conflicts with a jus cogens norm is void.[4] Traditionally, jus cogens has encompassed prohibitions against genocide, slavery, torture, and aggression. Its extension to environmental harm marks one of the most significant developments in contemporary international law.[5]
A related but distinct category involves “core obligations” under human rights treaties that are the minimum standards that states must fulfil regardless of resource constraints. The International Covenant on Economic, Social and Cultural Rights (“ICESCR”) General Comment No. 15 (2002) explicitly designates the core obligations attached to the right to water as non-derogable, stating that “a State party cannot justify its non-compliance with the core obligations,……. which are non-derogable”.[6]
The No-Harm Principle
The foundational non-derogable obligation in transboundary water law is the no-harm principle; the duty of states not to use their territory in a manner that causes significant harm to other states. This principle was applied in the Trail Smelter Arbitration (1941) and has since become a cornerstone of international environmental law.[7]
In transboundary water governance, the no-harm principle is codified in Article 7 of the UN Watercourses Convention. Article 7 obliges states to take all appropriate measures to prevent the causing of significant harm to other watercourse states. When such harm nonetheless occurs, the responsible state is required to take measures to eliminate or mitigate it and to discuss compensation.[8] The no-harm principle is likewise understood as an obligation of due diligence, requiring states to take all appropriate measures to prevent transboundary harm, while recognizing that they are not automatically liable where harm occurs despite the exercise of due diligence.[9]
Equitable and Reasonable Utilization
The second pillar of the UN Watercourses Convention, codified in Articles 5 and 6, is the principle of equitable and reasonable utilization. States are entitled to use shared watercourses in a manner that is equitable and reasonable, having regard to a non-exhaustive list of factors including geography, population, existing uses, economic and social needs, and the effects of use on other states.[10]
The relationship between equitable utilization and the no-harm principle is among the most contested issues in international water law. In the negotiations of the UN Watercourses Convention, state opinion was sharply divided: upstream countries (China, India, Ethiopia) tended to favour equitable utilization as the primary norm, while downstream countries supported the primacy of the no-harm rule.[11] The UN Watercourses Convention ultimately establishes no explicit hierarchy between these principles, instead requiring conflicts between competing uses to be resolved by reference to both.
The International Court of Justice (ICJ) provided important clarification in the Gabčíkovo-Nagymaros Project (Hungary v. Slovakia) case (1997), where it affirmed both principles as part of customary international law and highlighted the need for their mutual accommodation. More recently, in Pulp Mills on the River Uruguay (Argentina v. Uruguay) (2010), the Court articulated a “functional link” between procedural and substantive obligations, establishing that prior notification, environmental impact assessment, and consultation are not merely courtesy norms but legally required components of fulfilling substantive environmental obligations.[12]
Water as a Human Right in International Law
State-centric accounts of transboundary water law share a common limitation: they primarily conceptualize shared rivers as resources to be allocated between states, while paying insufficient attention to the welfare and rights of the individuals who depend upon them. Yet the people who lose access to safe water when a river is dammed, diverted, or contaminated are almost never parties to the dispute. A human rights framework addresses this limitation. It places the needs of affected populations at the centre of the analysis, and draws on a right now recognised in both international human rights law and international water law.[13]
The Right to Water under International Human Rights Law
The major human rights instruments drafted in the mid-twentieth century, including the Universal Declaration of Human Rights (UDHR) and the two 1966 Covenants[14], do not contain an express right to water. This gap was addressed in 2002, when the CESCR interpreted Articles 11 and 12 of the ICESCR as encompassing the human right to water, recognizing access to water as indispensable to both an adequate standard of living and the highest attainable standard of health.[15] This interpretation has since been widely accepted.
From a transboundary perspective, the most significant feature of the human right to water is that the obligations it imposes are not confined to a state’s territorial boundaries. Article 2(1) of the ICESCR requires each party to take steps “individually and through international assistance and co-operation” to realise Covenant rights, wording the Committee has treated as extending beyond a state’s own territory.[16]
General Comment No. 15 makes this obligation explicit, directing states to refrain from conduct that interferes with the enjoyment of the human right to water in other countries.[17] These obligations comprise three interrelated duties- to respect, protect, and fulfil the human right to water- each of which applies in the context of shared international watercourses. The duty to respect requires that an upstream state must not divert, deplete, or pollute a watercourse in a way that deprives downstream communities of the water they need to survive.[18] The duty to protect goes further, requiring the state to restrain third parties within its control, including private dam operators and industrial polluters, from violating the human right to water. A state that licenses or funds a project which foreseeably damages a neighbouring population’s water supply may therefore be answerable for its failure to regulate it.[19] The duty to fulfil calls on states, where they are in a position to do so, to help realise the human right to water through international assistance and cooperation.[20]
The Right to Water under International Water Law
The protection of the human right to water is not derived solely from international human rights law. International water law reinforces this protection through a different legal framework by according priority to the satisfaction of vital human needs. Where competing uses of a shared watercourse cannot be reconciled, Article 10 of the UN Watercourses Convention requires that the conflict be resolved with “special regard” for vital human needs, which in practice places industrial and commercial uses below the water needed for human survival.[21] The Berlin Rules adopt a more expansive approach by requiring states to prioritize the allocation of water for vital human needs over all other uses, defining such needs as the water required for drinking, cooking, sanitation, and the immediate subsistence of a household.[22]
The strongest connection to a rights-based approach is found in Article 17 of the Berlin Rules, which recognizes the right of every individual to sufficient, safe, acceptable, physically accessible, and affordable water for vital human needs, to be provided on a non-discriminatory basis.[23] Although the provision does not expressly refer to the “human right to water,” it embodies the substantive content of that right together with the tripartite framework of obligations to respect, protect, and fulfill derived from international human rights law. This overlap is not accidental: General Comment No. 15 itself gives priority to water for personal and domestic use and for the prevention of disease, which follows the same order of priority that water law builds around vital human needs.[24]
Key Challenges and Gaps
The Enforcement Gap
The most persistent challenge in transboundary water governance is the absence of compulsory enforcement mechanisms. International environmental obligations are only as effective as the institutions and processes available to implement them. The UN Watercourses Convention’s dispute resolution provisions (Article 33) are non-compulsory, providing for fact-finding commissions (that can only operate with state consent). Only thirty-seven states have ratified the Convention, leaving significant river basins, including the Nile, Lancang-Mekong, and Brahmaputra, outside its formal scope.
No Clear Definition of “Significant Harm”
The no-harm rule’s threshold of “significant” harm has never been comprehensively defined. Significance can apply to individuals, communities, or entire national economies and the harm can be immediate or build slowly over years, affecting ecosystems, livelihoods, or public health. The ICJ has addressed individual cases without settling these broader questions, leaving state practice fragmented and inconsistent. In practical terms, this ambiguity tends to favour upstream actors, who retain wide discretion to dismiss downstream damage as falling below the threshold, even when affected communities are already experiencing measurable water insecurity, crop failure, or ecosystem loss.
Power Imbalances in Shared Waters
Transboundary water governance is profoundly shaped by power disparities between upstream and downstream states. Hydro-hegemonic states that are able to control water flows by virtue of geography, infrastructure, and political power can effectively side-step formal legal obligations by refusing to engage in compulsory dispute mechanisms. Non-derogable obligations provide a formal counter-weight, but without enforcement, their effect on state behaviour is limited.
Policy Recommendations
For States:
- Expand Treaty Ratification and Harmonization: States should ratify both the UN Watercourses Convention and the UNECE Water Convention, which is open to global membership. The limited number of ratifications continues to represent a significant structural weakness in the international legal framework governing transboundary water resources. States should also seek to align basin-specific agreements with the core principles embodied in these conventions.
- Integrate Climate Adaptation into Governance Frameworks: Transboundary water treaties and the mandates of river basin commissions should expressly incorporate obligations relating to climate change adaptation, including joint monitoring, the exchange of hydrological data, and collaborative scenario planning. These obligations should extend beyond broad commitments by prescribing minimum data-sharing requirements, establishing joint technical bodies with the authority to initiate treaty review or renegotiation when agreed flow thresholds are exceeded, and integrating transboundary water governance with national climate adaptation commitments.
- Operationalize Non-Derogable Human Rights Obligations: States should incorporate the non-derogable core obligations set out in General Comment No. 15 into domestic legislation and bilateral and multilateral water agreements. They should also include the requirement to conduct human rights impact assessments prior to approving upstream infrastructure projects, ensure that transboundary water allocation agreements expressly safeguard the minimum water needs of downstream populations, and establish effective domestic legal mechanisms through which affected communities can seek redress where these obligations are violated.
For Pakistan
- Ratify and Champion the 1997 Watercourses Convention: Pakistan has not ratified the UN Watercourses Convention, limiting its ability to rely on the Convention’s principles of equitable and reasonable utilization and the obligation not to cause significant harm in international forums. Ratification would strengthen Pakistan’s legal position in future disputes while demonstrating its commitment to a rules-based framework for transboundary water governance, thereby enhancing its diplomatic credibility when seeking third-party support in disputes with more powerful upstream neighbours.
- Ground Water Claims within Human Rights Law: Pakistan should frame its water security claims not only in terms of treaty-based entitlements but also by invoking the human right to water as articulated in CESCR General Comment No. 15. As disruptions to the flows of the Indus River directly threaten the water and food security of millions of Pakistanis, characterizing upstream interference as a breach of non-derogable human rights obligations strengthens both the legal and normative basis of Pakistan’s position. This approach also expands potential avenues for accountability, including engagement with UN treaty bodies, the Special Rapporteur on the human rights to safe drinking water and sanitation, and other international human rights mechanisms.
- Invest in Domestic Water Governance and Efficiency: Pakistan’s position in transboundary water disputes is undermined by persistent shortcomings in domestic water governance, including substantial agricultural water losses, ageing irrigation infrastructure, and inadequate regulation of groundwater resources. Strengthening domestic water management would not only reduce Pakistan’s vulnerability to upstream fluctuations but also weaken claims that downstream water insecurity is primarily the result of internal mismanagement rather than external actions.
- Build Regional and Multilateral Coalitions: Pakistan is not unique in facing downstream vulnerability; Bangladesh, Egypt, and several other states occupy comparable structural positions within transboundary river systems. Pakistan should therefore strengthen cooperation with other downstream states to advocate collectively for the progressive development of international water law, including wider ratification of the UN Watercourses Convention, more effective dispute settlement mechanisms, and the recognition of a jus cogens prohibition against irreversible transboundary environmental harm. Such efforts should be advanced through multilateral forums, including the UN General Assembly, the Human Rights Council, and international climate negotiations, where water security is assuming increasing prominence.
[1] Wambua Kituku, ‘The Doctrine of Equitable and Reasonable Utilization of International Water and Its Application under International Watercourses Law’ (Academia.edu) https://www.academia.edu/15194711
[2]Amir AghaKouchak and others, ‘Transboundary Water Conflicts, Cooperation, and Pathways Forward’ Proceedings of the National Academy of Sciences https://www.pnas.org/doi/10.1073/pnas.2537439123; Ashok Swain, ‘Transboundary Water Security in a Warming World: Conflict Risks, Cooperation Pathways, and Policy Imperatives’ (TRENDS Research & Advisory) https://trendsresearch.org/insight/transboundary-water-security-in-a-warming-world-conflict-risks-cooperation-pathways-and-policy-imperatives/
[3] United Nations, International Covenant on Civil and Political Rights (adopted 16 December 1966, entered into force 23 March 1976) 999 UNTS 171, art 4 https://www.ohchr.org/en/instruments-mechanisms/instruments/international-covenant-civil-and-political-rights
[4] United Nations, Vienna Convention on the Law of Treaties (adopted 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331, art 53 https://legal.un.org/ilc/texts/instruments/english/conventions/1_1_1969.pdf
[5] Inter-American Court of Human Rights, Advisory Opinion OC-32/25 on the Climate Emergency and Human Rights (Advisory Opinion) OC-32/25 (29 May 2025)
[6] UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11. https://humanrights.asn.au/ICESCR/GeneralComment15
[7] Joseph W Dellapenna, ‘The Customary International Law of Transboundary Fresh Waters’ (2001) 1(3–4) International Journal of Global Environmental Issues 264 https://www.cawater-info.net/bk/water_law/pdf/dellapenna.pdf
[8] Laurence Boisson de Chazournes, ‘The Role of International Case Law in Implementing the Obligation Not to Cause Significant Harm’ (2020) 21 International Environmental Agreements: Politics, Law and Economics 63 https://link.springer.com/article/10.1007/s10784-020-09503-6
[9] ‘The Positive Obligation to Prevent Climate Harm Under International Law’ (2023) 35 Georgetown Environmental Law Review https://www.law.georgetown.edu/environmental-law-review/wp-content/uploads/sites/18/2023/05/The-Positive-Obligation-to-Prevent-Climate-Harm.pdf
[10] Kituku, ‘The Doctrine of Equitable and Reasonable Utilization’.
[11] Salman MA Salman, ‘The Inter-Relationship between No Harm, Equitable and Reasonable Utilisation and Cooperation under International Water Law’ (2020) 21 International Environmental Agreements: Politics, Law and Economics 25 https://link.springer.com/article/10.1007/s10784-020-09502-7
[12] Shahwar Kazi, ‘International Court of Justice on Transboundary Harm: Reflections on South Asian Transboundary Water Governance’ in Water Governance in South Asia (Springer Nature 2026) https://link.springer.com/chapter/10.1007/978-981-96-7691-0_10
[13] UNGA Res 64/292 (28 July 2010) UN Doc A/RES/64/292.
[14] International Covenant on Civil and Political Rights and the International Covenant on Economic, Social and Cultural Rights.
[15] UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, paras 2–3.
[16] International Covenant on Economic, Social and Cultural Rights (adopted 16 December 1966, entered into force 3 January 1976) 993 UNTS 3, art 2(1).
[17]UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, para 31.
[18]UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, paras 21–22.
[19]UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, para 23.
[20]UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, paras 25 and 34.
[21]Convention on the Law of the Non-Navigational Uses of International Watercourses (adopted 21 May 1997, entered into force 17 August 2014) (1997) 36 ILM 700, art 10.
[22]International Law Association, Berlin Rules on Water Resources (2004) arts 14 and 3.
[23]International Law Association, Berlin Rules on Water Resources (2004) art 17.
[24]UN Committee on Economic, Social and Cultural Rights, General Comment No 15: The Right to Water (2003) UN Doc E/C.12/2002/11, para 6.
