The Indus Waters Treaty: CSS Solved Answer

Exam question: CSS 2025, Q2: How did the Indus Waters Treaty (1960) affect water distribution and relations between Pakistan and India?

Syllabus topic: Topic XVII of the CSS Pakistan Affairs syllabus.

Short answer

Outline for quick revision

Introduction: mediate the Indus dispute
Background to the Treaty: The 1948 water crisis; World Bank mediation
How the Treaty Distributed the Waters: Eastern rivers to India; Western rivers to Pakistan; Replacement works; Institutions and dispute resolution
Effects on Water Distribution: Security of supply for Pakistan; Costs for Pakistan; Internal effects; Climate change
Effects on Pakistan-India Relations: A model of cooperation (1960-2016); Growing tensions (2016-2024); Crisis (2025-2026)
Way Forward for Pakistan
Conclusion

Reference colours:
Quotation / documentPersonality / historySyllabus bookCurrent referenceOfficial report / policy

1. Introduction

Pakistan is an agricultural country that depends almost entirely on one river system, the Indus and its tributaries, and most of these rivers rise in or pass through Indian-held territory. When the Radcliffe line left key headworks at Madhopur and Ferozepur in India, water became a question of survival for Pakistan.

The Indus Waters Treaty, signed in Karachi on 19 September 1960 by Jawaharlal Nehru and Ayub Khan with the World Bank as a signatory, divided the rivers between the two countries. The question has two parts, water distribution and relations, so this answer covers both. It argues that the Treaty settled water distribution for six decades and survived three wars, but India’s decision to hold it “in abeyance” in 2025 has turned water into a new front in India-Pakistan hostility.

“No army, with bombs and shellfire, could devastate a land as thoroughly as Pakistan could be devastated by the simple expedient of India’s permanently shutting off the sources of water that keep the fields and people of Pakistan green.”
David Lilienthal, former head of the Tennessee Valley Authority, Collier’s magazine, 1951, the article that led the World Bank to

mediate the Indus dispute

2. Background to the Treaty

The 1948 water crisis

On 1 April 1948, India stopped the flow of water from the headworks under its control into Pakistan’s canals, threatening crops in Punjab. A temporary agreement (May 1948) restored supply, but showed Pakistan’s vulnerability.

World Bank mediation

After Lilienthal’s proposal in 1951, the World Bank under Eugene Black mediated for nine years, leading to the Treaty of 1960, one of the few successful India-Pakistan agreements.

Syllabus book: Victoria Schofield, Kashmir in Conflict (2003), traces the Kashmir dispute to 1947 and shows why control of Kashmir, where the headwaters of Pakistan’s rivers lie, is a matter of survival, not only territory, for Pakistan.

3. How the Treaty Distributed the Waters

Eastern rivers to India

The three eastern rivers, Ravi, Beas and Sutlej, were given to India for its exclusive use, after a transition period.

Western rivers to Pakistan

The three western rivers, Indus, Jhelum and Chenab, carrying about 80% of the system’s water, were given to Pakistan. India may use them only for limited purposes: domestic use, limited irrigation, and run-of-river hydropower with restricted storage, under strict design criteria.

Replacement works

Because Pakistan lost the eastern rivers, the Indus Basin Project, financed by the World Bank, friendly countries and a contribution from India, built Mangla (1967) and Tarbela (1976) dams, barrages and eight link canals to carry western river water to areas once fed by the eastern rivers.

Institutions and dispute resolution

A Permanent Indus Commission, with a commissioner from each country, exchanges data and meets regularly. Disputes go through a three-step process: the Commission, a Neutral Expert for technical questions, and a Court of Arbitration for legal disputes.

Division of the Indus rivers

Eastern rivers, India: Ravi, Beas, Sutlej
Western rivers, Pakistan: Indus, Jhelum, Chenab (about 80% of flows)
Mechanism: Indus Commission, Neutral Expert, Court of Arbitration

4. Effects on Water Distribution

Security of supply for Pakistan

The Treaty gave Pakistan legal rights to most of the system’s water and the infrastructure to use it, allowing its irrigated agriculture to expand.

Costs for Pakistan

Pakistan lost the eastern rivers entirely; the Ravi and Sutlej are now often dry in Pakistan, harming groundwater, ecology and cities like Lahore.

Internal effects

Distribution of the western waters among Pakistan’s provinces became a domestic issue, settled by the Water Apportionment Accord of 1991 but still contested by Sindh.

Climate change

The Treaty did not anticipate glacier melt, floods and droughts; climate change now makes timely data-sharing more important than ever.

Official report / policy: The World Bank’s Country Climate and Development Report for Pakistan (November 2022) warned that climate change and environmental degradation could cut GDP by 18-20% a year by 2050, and estimated that Pakistan needs $348 billion (2023-2030), $152 billion for adaptation and $196 billion for decarbonisation.

5. Effects on Pakistan-India Relations

A model of cooperation (1960-2016)

Survived wars

The Treaty survived the wars of 1965, 1971 and 1999 (Kargil); the Indus Commission kept meeting even when other relations were frozen.

Legal resolution of disputes

Disputes over Indian projects were handled through the Treaty: the Salal dam (settled bilaterally in 1978), Baglihar (Neutral Expert, 2007) and Kishanganga (Court of Arbitration, 2013).

Growing tensions (2016-2024)

Indian dams on the western rivers

India’s run-of-river projects on the Jhelum and Chenab, Kishanganga, Ratle and others, raised Pakistani fears that India could manipulate flows at critical times for sowing.

Political threats

After the Uri attack (2016), Prime Minister Modi declared that “blood and water cannot flow together”; India later sent notices (2023 and 2024) seeking to modify the Treaty.

Crisis (2025-2026)

The abeyance

After the Pahalgam attack, India declared the Treaty “in abeyance”, the first time it has tried to suspend it.

Current reference: After the Pahalgam attack, India placed the Indus Waters Treaty (1960) “in abeyance” on 23 April 2025; Pakistan’s National Security Committee declared that any attempt to stop or divert its water would be treated as an act of war. The river dispute that began when the 1947 boundary left key headworks in India is still unresolved.

Legal victories for Pakistan

International arbitration has repeatedly upheld the Treaty, but India refuses to accept these rulings.

Official report / policy: The Court of Arbitration under the Indus Waters Treaty (Permanent Court of Arbitration, The Hague) ruled on 27 June 2025 that India’s “abeyance” did not limit its authority; on 8 August 2025 it held that India must “let flow” the waters of the western rivers and build run-of-river projects strictly within the Treaty’s design limits; and on 31 August 2026 it unanimously found that the Treaty “remains fully in force” and that no state can suspend it unilaterally. India rejected the court as “illegally constituted”.

Current tensions

Data-sharing and the Commission have stopped functioning, and water has become a possible trigger of war.

Current reference: The Permanent Indus Commission has not met since May 2022, and Pakistan says India has stopped sharing flow data and allowing inspections; Pakistani officials have reported unusual fluctuations in the Chenab. On 21 October 2026, PM Shehbaz Sharif repeated that any Indian violation of the Treaty would be treated as an “act of war”.

Syllabus book: P.R. Chari, Pervaiz Iqbal Cheema and Stephen P. Cohen, Perception, Politics and Security in South Asia: The Compound Crisis of 1990 (2003), show how, in a nuclear South Asia, misperception between India and Pakistan can turn a local crisis into a nuclear danger that draws in outside powers.

6. Way Forward for Pakistan

Pakistan should continue to defend the Treaty through legal and diplomatic channels, the Court of Arbitration, the World Bank and the UN, and highlight internationally that unilateral suspension sets a dangerous precedent for all shared rivers; build its own storage and modernise irrigation to reduce vulnerability; strengthen its Indus Commission office with technical and legal experts; and keep the door open for India to return to the Treaty’s mechanisms, including climate cooperation and data-sharing.

7. Conclusion

The Indus Waters Treaty divided the Indus rivers, the eastern to India and the western to Pakistan, and, with the Indus Basin Project, secured Pakistan’s agriculture for six decades. It survived three wars and resolved disputes through law, making it a rare model of India-Pakistan cooperation. But since 2016, and especially since India’s “abeyance” of April 2025, water has become a weapon of pressure. International arbitration has upheld the Treaty, but its future depends on India’s compliance and on Pakistan’s ability to defend its rights and manage its water wisely. For Pakistan, as the Prime Minister has warned, water is a red line.

The Indus Waters Treaty: CSS 2025 Solved Answer