Transboundary rivers: Indus, Ganga, Teesta and Brahmaputra

Detail

1. What a transboundary river is

• Transboundary river: a river that flows through, or forms the border between, two or more countries.
• One country's dam, canal or diversion changes how much water reaches the next country, and when.
• Upstream (upper riparian) country: the country nearer the river's source. It controls the flow first.
• Downstream (lower riparian) country: the country nearer the mouth. It depends on what comes down to it.
• India's double position:
• India is upstream of Pakistan (Indus system) and Bangladesh (Ganga, Teesta, Brahmaputra).
• India is downstream of China on the Brahmaputra (Yarlung Tsangpo) and the Satluj, both of which rise in Tibet.
• So India cannot argue only for upstream rights or only for downstream rights. Its stand on sharing rivers has to balance both.

2. Indus Waters Treaty (1960)

Basic facts

• Indus Waters Treaty (IWT): a water-sharing agreement between India and Pakistan for the six rivers of the Indus system.
• Signed in Karachi on 19 September 1960 by Jawaharlal Nehru (India) and Field Marshal Ayub Khan (Pakistan).
• World Bank role:
• It came after nine years of talks. Former World Bank President Eugene Black started the process [2].
• The World Bank is also a signatory of the treaty [2].

• Its role is limited to procedure. It helps set up the dispute bodies and names the Neutral Expert or Court of Arbitration members when asked [2].

• The treaty is often called one of the most successful international water treaties. It survived many India-Pakistan conflicts [2].

How the rivers are divided

Group	Rivers	Allotted to	Spatial anchor
Eastern rivers	Ravi, Beas, Satluj	India (unrestricted use)	Satluj rises near Rakas Lake in Tibet and enters India at Shipki La (Himachal Pradesh)
Western rivers	Indus, Jhelum, Chenab	Pakistan	Indus rises near Lake Mansarovar (Tibet) and flows through Ladakh into Pakistan. Jhelum rises at Verinag (J&K). Chenab is formed by the Chandra and Bhaga at Tandi (Himachal Pradesh)

• India's limited rights on the western rivers:
• Domestic use (drinking, household needs).
• Non-consumptive use: use that returns the water to the river, such as navigation or fish farming.
• Limited irrigation, within fixed limits.

• Run-of-river hydropower: power plants that use the river's natural flow and keep little or no water in storage, so the flow downstream is not cut.

• Each country keeps certain uses on the rivers given to the other [2].

How disputes are handled: three levels

• Permanent Indus Commission (PIC): has one Commissioner from each country. It is the channel for working together and sharing information [2].
• Three kinds of problems, each with its own route [2]:

Level	Type of issue	Who decides
1	"Questions"	Permanent Indus Commission
2	"Differences" (technical)	Neutral Expert
3	"Disputes" (legal)	Ad hoc Court of Arbitration

Kishanganga and Ratle disputes

• Both are Indian hydropower plants on tributaries of the western rivers [2].
• Kishanganga: 330 MW, opened 2018 [2]. It is on the Kishanganga (Neelum) river, a Jhelum tributary, in J&K.

• Ratle: 850 MW, under construction [2]. It is on the Chenab in J&K.

• Pakistan objected that their designs break the treaty [2].

• Pakistan asked for a Court of Arbitration. India asked for a Neutral Expert.
• In October 2022 the World Bank named Michel Lino as Neutral Expert and Sean Murphy as Chairman of the Court of Arbitration [2].
• Both processes started on 21 November 2022 and ran side by side [2]. India objected to two forums hearing the same issue.

Treaty in abeyance (2025)

• Abeyance: the treaty is put on hold. India stops carrying it out, but has not formally ended it.
• Cause → action → stand:
• 22 April 2025: terror attack at Pahalgam (J&K).
• 23 April 2025: India decided to hold the IWT in abeyance, effective immediately.

• India says the treaty stays on hold until Pakistan credibly and irrevocably stops supporting cross-border terrorism. (Status as of 2025; check for later changes.)

• What follows on the ground: India is pushing storage and hydropower projects on the western rivers in J&K, such as on the Chenab. It also no longer has to share hydrological data with Pakistan in the same way.

Map link: where India uses its eastern-river water

• Bhakra Nangal Project on the Satluj (Himachal Pradesh–Punjab). This was a Nehru-era multipurpose project, one of his "temples of modern India".
• Indira Gandhi Canal (Rajasthan Canal) starts at the Harike Barrage, where the Satluj and Beas meet in Punjab. It carries water into the Thar Desert of western Rajasthan.
• Heavy irrigation in Punjab has also used up a lot of groundwater (NCERT Class 8 example of a resource being overused).

3. Ganga Waters Treaty (1996)

Farakka Barrage: the root of the issue

• Barrage: a low dam with gates. It raises the water level and turns flow into a canal. It stores little water.
• Farakka Barrage, in Murshidabad district, West Bengal, close to the Bangladesh border. It started working in 1975.
• Why it was built (cause → process → result):
• Silt was building up in the Hugli (Hooghly), the river that carries ships to Kolkata port.
• So the barrage turns part of the Ganga's water into a feeder canal, which sends it into the Bhagirathi–Hugli.
• The extra flow flushes the silt away and keeps Kolkata port navigable.
• Result: less Ganga water flows on into Bangladesh (where the river is called the Padma) in the dry season. This became a dispute.

The 1996 treaty

• Ganga Waters Treaty: an India–Bangladesh agreement on sharing the Ganga's dry-season flow at Farakka.
• Signed 12 December 1996.
• Lean season: 1 January–31 May, when the river carries its least water.
• Flow is measured and shared in 10-day blocks.
• A guaranteed minimum is set for each side in the leanest periods (commonly cited as 35,000 cusecs in alternate 10-day blocks, March–May).
• A Joint Committee watches over the flow at Farakka. The Joint Rivers Commission (set up in 1972) is the wider India–Bangladesh body on shared rivers.
• Term: 30 years. It expires in December 2026. Renewal talks are a live issue as of 2026, and India says they go through existing bilateral bodies.
• Pressures on renewal:
• Dry-season flows are lower because more water is used upstream in Indian states.
• Bangladesh says it gets less than its share in dry years.
• West Bengal says Kolkata port and its own water needs must be protected.

4. Teesta water dispute

The river

• Origin: glaciers and lakes of north Sikkim (Tso Lhamo/Zemu glacier area) in the Eastern Himalaya.
• Course: Sikkim → West Bengal (it comes out onto the plains near Sevoke, then flows past Jalpaiguri) → Bangladesh (Rangpur region).
• Mouth: it joins the Brahmaputra (called the Jamuna in Bangladesh).
• Gajoldoba Barrage (West Bengal, India) and Dalia Barrage (Bangladesh) both take Teesta water for irrigation.

The dispute

• Teesta water dispute: the long-running India–Bangladesh disagreement over sharing the Teesta's dry-season flow.
• Cause: in the dry season the Teesta is very low. North Bengal (India) and northern Bangladesh both need it for winter rice and irrigation.
• 2011: an interim dry-season sharing deal was ready for signing during PM Manmohan Singh's visit to Dhaka.
• West Bengal objected. It feared less water for its own farmers.

• The deal was not signed. Water is a state subject under India's Constitution, so the Centre needs the state on board in practice.

• China factor: Bangladesh has been weighing a Chinese-backed Teesta River Comprehensive Management and Restoration Project (dredging, embankments, reservoirs). India has offered its own help for Teesta conservation. (Status as of 2025; check for later changes.)

• Why it matters to India: a Chinese project close to the Siliguri Corridor ("Chicken's Neck", the narrow land strip that links mainland India to the North-East) is a strategic worry.

5. Brahmaputra and China: Medog project

The river (Brahmaputra system)

Name	Where
Yarlung Tsangpo	Tibet (China). Rises at the Chemayungdung glacier near Lake Mansarovar and flows east
Great Bend	Tibet. The river takes a sharp U-turn around Namcha Barwa (7,782 m) through a very deep gorge
Siang / Dihang	Arunachal Pradesh (India). It enters India here
Brahmaputra	Assam. Formed after the Siang meets the Dibang and Lohit near Sadiya
Jamuna	Bangladesh. Joins the Padma (Ganga), then the Meghna, and flows into the Bay of Bengal

Medog (Motuo) Hydropower Project

• Medog hydropower project: a very large Chinese hydropower scheme of about 60 GW on the lower reaches of the Yarlung Tsangpo, near the Great Bend in Medog (Motuo) county, Tibet. It is close to Arunachal Pradesh.
• China began construction in July 2025.
• When finished it would be the world's largest hydropower project, much bigger than China's Three Gorges Dam.
• The Great Bend is suited to it because:
• The river drops about 2,000 m over a short distance there.
• A steep drop gives high water pressure, which means huge power potential.

India's concerns

• Flow: China could hold back or release water. This would change how much water reaches Arunachal and Assam, especially in the lean season.
• Sediment: dams trap silt. Less silt downstream means less fertile soil on Assam's floodplains and in the Bangladesh delta.
• Flood timing: a sudden release, or a dam failure, could cause flash floods downstream.
• Seismic risk: the region is a very active earthquake zone (the 1950 Assam–Tibet earthquake, magnitude 8.6).
• Data sharing:
• India and China have hydrological data MoUs. Under these China supplies flood-season flow data for the Brahmaputra and Satluj.
• Some MoUs have lapsed and renewal has been slow, so India gets fewer early flood warnings.
• There is no water-sharing treaty between India and China. There is only an Expert Level Mechanism (2006).

India's response: Siang Upper Multipurpose Project (SUMP)

• A planned large storage dam on the Siang in Arunachal Pradesh (Upper Siang district). It would hold a few billion cubic metres of water.
• How it is meant to work (as a buffer):
• The reservoir could absorb a sudden release of water from China, which cuts flood risk.
• It could store water to cover any lean-season shortfall.

• It would also produce hydropower.

• Local opposition: the Adi tribal communities fear that villages, farmland and forests would be flooded, and that they would lose their homes and culture. Protests have slowed the pre-feasibility surveys. (Status as of 2025; check for later changes.)

6. Big picture: India's position across its rivers

River system	Partner	India's position	Legal framework
Indus	Pakistan	Upstream	IWT 1960 (in abeyance since April 2025)
Ganga	Bangladesh	Upstream	Ganga Waters Treaty 1996 (expires December 2026)
Teesta	Bangladesh	Upstream	No treaty (2011 deal not signed)
Brahmaputra	China (and Bangladesh downstream)	Downstream of China, upstream of Bangladesh	Only data MoUs and the Expert Level Mechanism

• The policy problem: whatever India demands from China as a downstream country (data, transparency, consultation), Pakistan and Bangladesh can ask of India.
• Links: diplomacy in india-neighbours; river courses in india-drainage-rivers.

Prelims Hooks

• IWT 1960 was signed in Karachi, with the World Bank as a signatory, after nine years of talks started by Eugene Black.
• Eastern rivers (India): Ravi, Beas, Satluj. Western rivers (Pakistan): Indus, Jhelum, Chenab. Trap: the Chenab is a western river even though it rises in Himachal Pradesh.
• IWT dispute ladder: Questions → Permanent Indus Commission. Differences → Neutral Expert. Disputes → Court of Arbitration.
• Kishanganga (330 MW) is on a Jhelum tributary. Ratle (850 MW) is on the Chenab. Both are in J&K.
• Farakka Barrage (West Bengal, 1975) sends water into the Hugli to flush silt and protect Kolkata port.
• Ganga Waters Treaty: signed 12 December 1996, lean season January–May, 10-day blocks, 30-year term, expires December 2026.
• The Teesta rises in Sikkim, flows through West Bengal, and joins the Brahmaputra (Jamuna) in Bangladesh.
• Brahmaputra names in order, upstream to downstream: Yarlung Tsangpo (Tibet) → Siang/Dihang (Arunachal) → Brahmaputra (Assam) → Jamuna (Bangladesh).
• Medog/Motuo project: about 60 GW, at the Great Bend of the Yarlung Tsangpo near Namcha Barwa, construction began July 2025.
• The Siang Upper Multipurpose Project is in Arunachal Pradesh. The Adi community opposes it.

Mains Points

• India as both upstream and downstream country: India is upstream of Pakistan and Bangladesh but downstream of China. So its demands on China (data sharing, transparency, consultation before building) have to match how it treats its own neighbours. This is a key point in any GS-II/GS-I answer on river diplomacy.
• IWT in abeyance (April 2025): India now links water to security. Building storage and run-of-river projects on the Chenab and Jhelum can help J&K's power and irrigation. The risks: questions over international law, and a precedent that China could use on the Brahmaputra. The 2022 parallel Neutral Expert and Court of Arbitration processes showed the treaty's dispute system breaking down [2].
• Eastern rivers (Ganga, Teesta): the 2026 Ganga Treaty renewal and the stalled Teesta deal show a Centre–state tension. Water is a state subject, and West Bengal's needs (Kolkata port, North Bengal irrigation) clash with Bangladesh's dry-season demands. China's Teesta offer adds a strategic angle near the Siliguri Corridor.
• Mega dams and disaster risk (GS-III): Medog and the Siang project both sit in a high-seismic, landslide-prone zone. Possible effects: less silt reaching Assam's floodplains and the Bangladesh delta, sudden floods from dam releases, and tribal displacement (Adi). Possible responses: basin-level data sharing, early-warning systems, and assessing the cumulative impact of all projects together.