The Indus system

Detail

1. The Indus river: key figures

• Indus river: a Himalayan river. It rises in Tibet, crosses Ladakh and Pakistan, and ends in the Arabian Sea. Its basin (all the land that drains into one river and its tributaries) is one of the largest in the world.

Measure	Total	Share in India
Basin area	11,65,000 sq km	3,21,289 sq km
Length	2,880 km	1,114 km

• How the Indian part of the basin is split by state (CWC):
• Jammu and Kashmir (including Ladakh): 1,93,762 sq km
• Himachal Pradesh: 51,356 sq km
• Punjab: 50,304 sq km
• Rajasthan: 15,814 sq km
• Haryana: 9,939 sq km
• Chandigarh: 114 sq km [2]

• Ranking by area: J&K > Himachal Pradesh > Punjab > Rajasthan > Haryana > Chandigarh [2].

• Water in the Indian part (CWC):

• Average water resource potential: 73,310 MCM (million cubic metres).
• Usable surface water: 46,000 MCM.
• Live storage of completed projects: 16,222 MCM. Projects still being built add 100 MCM, so the total is 16,322 MCM [2].
• About 87% of the usable surface water is already used. Groundwater use is about 71% [2].
• CWC runs 26 hydrological observation stations in the basin but has 0 flood-forecasting stations there [2]. This gap matters in flood years (see section 6).

2. Source and upper course

• Source: near the Bokhar Chu glacier (31°15'N, 81°40'E), at 4,164 m, in the Kailash range of Tibet (China).
• Local name: Singi Khamban ("Lion's mouth").
• Direction: it flows north-west between the Ladakh range (to the north) and the Zaskar range (to the south), through Ladakh and Baltistan.
• Gorge: it cuts across the Ladakh range and makes a deep gorge near Gilgit.

• The river is older than the mountains. As the Himalaya slowly rose, the river kept cutting down through them. A river like this is called antecedent, and it leaves a deep gorge behind.

• Entry into Pakistan: near Chilas, in the Dardistan region.

• In India, it flows only through Ladakh and Jammu and Kashmir.

3. Tributaries of the main Indus

• Himalayan tributaries: the Shyok, Gilgit, Zaskar, Hunza, Nubra, Shigar, Gasting and Dras.
• Shyok river:
• It rises from the Rimo glacier near the Karakoram range.
• It receives the Nubra river.
• It joins the Indus in Baltistan.

• The Galwan river is a tributary of the Shyok. It flows through the Galwan valley in eastern Ladakh, close to the India–China border (the Line of Actual Control).

• Leaving the hills: the Indus comes down from the mountains at Attock in Pakistan. There the Kabul river (from Afghanistan) joins it on the right bank.

• Other right-bank tributaries rise in the Sulaiman range: the Khurram, Tochi, Gomal, Viboa and Sangar.
• Left bank: the Panjnad joins the Indus a little above Mithankot.
• Mouth: the Indus ends in the Arabian Sea, east of Karachi.

Bank	Main tributaries	Where they come from
Right (west)	Kabul, Khurram, Tochi, Gomal, Viboa, Sangar	Afghanistan; Sulaiman range
Left (east)	Panjnad (Jhelum, Chenab, Ravi, Beas, Satluj)	Himalaya (Pir Panjal, Lahul, Kullu, Tibet)
Upper Himalayan	Shyok, Nubra, Gilgit, Hunza, Zaskar, Shigar, Gasting, Dras	Karakoram and Ladakh–Zaskar ranges

4. The Panjnad: five rivers of Punjab

• Panjnad ("five rivers"): the five eastern tributaries that give Punjab its name. They are the Jhelum, Chenab, Ravi, Beas and Satluj.
• Trap: the Indus itself is not one of the five.
• Order from west to east: Jhelum → Chenab → Ravi → Beas → Satluj.

Jhelum

• Source: a spring at Verinag, at the foot of the Pir Panjal range, in the south-east of the Kashmir valley.
• Course: it flows through Srinagar and then through Wular lake (a freshwater lake in Kashmir).
• It enters Pakistan through a deep, narrow gorge.
• Confluence: it joins the Chenab near Jhang in Pakistan.

Chenab

• It is the largest tributary of the Indus.
• Formation: two streams, the Chandra and the Bhaga, meet at Tandi near Keylong in Himachal Pradesh. So it is also called the Chandrabhaga.
• It flows 1,180 km before it enters Pakistan.
• Chenab Rail Bridge:
• It stands 359 m above the riverbed. It is the world's highest railway arch bridge, 35 m higher than the Eiffel Tower [3].
• It is a 1,315 m long steel arch bridge on the Udhampur–Srinagar–Baramulla Rail Link (USBRL) [3].
• It is built to stand winds of up to 260 km/h and to last 120 years [3].
• It was opened in June 2025, together with India's first cable-stayed rail bridge at Anji [3].

Ravi

• Source: west of the Rohtang pass, in the Kullu hills of Himachal Pradesh.
• Course: it flows through the Chamba valley, which lies between the Pir Panjal and the Dhauladhar ranges.
• It enters Pakistan below Madhopur and joins the Chenab near Sarai Sidhu.

Beas

• Source: Beas Kund, near the Rohtang pass, at about 4,000 m.
• Course: it flows through the Kullu valley. It cuts gorges at Kati and Largi in the Dhauladhar range.
• Confluence: it meets the Satluj at Harike in Punjab.
• It is the only Panjnad river that lies wholly in India.
• The Harike barrage, at the meeting point, sends water into the Indira Gandhi Canal, which irrigates the Thar desert in Rajasthan.

Satluj

• Source: Rakas Tal, near Mansarovar lake in Tibet, at 4,555 m. There it is called the Langchen Khambab.
• Course: it flows almost parallel to the Indus for about 400 km. It enters India through Shipki La (a pass on the Himachal–Tibet border).
• Antecedent river: it is older than the Himalaya and kept its path by cutting a gorge through the rising ranges.
• It comes out of its gorge at Rupar (Ropar) in Punjab.
• Uses:
• It feeds the Bhakra Nangal project's canal system.
• It is linked to the Beas by the Beas–Satluj link, which moves Beas water into the Satluj for power and irrigation.

Comparison of the five rivers

River	Source	Key valley or gorge	Joins	Countries
Jhelum	Verinag spring (Pir Panjal)	Srinagar, Wular lake; gorge into Pakistan	Chenab near Jhang	India, Pakistan
Chenab	Chandra + Bhaga at Tandi (Keylong)	1,180 km in India	Indus (via Panjnad)	India, Pakistan
Ravi	W of Rohtang pass (Kullu hills)	Chamba valley	Chenab near Sarai Sidhu	India, Pakistan
Beas	Beas Kund (~4,000 m)	Kullu valley; Kati, Largi gorges	Satluj at Harike	India only
Satluj	Rakas Tal (4,555 m), Tibet	Shipki La; gorge to Rupar	Chenab-Panjnad system	China, India, Pakistan

5. Indus Waters Treaty, 1960

• Indus Waters Treaty (IWT): a 1960 agreement between India and Pakistan, made with World Bank help. It decides how the six rivers of the Indus system are shared [4].

Group	Rivers	Who gets them
Eastern rivers	Ravi, Beas, Satluj	India: full use
Western rivers	Indus, Jhelum, Chenab	Pakistan; India allowed limited non-consumptive use

• Non-consumptive use: using water without using it up. In run-of-river hydropower, flowing water turns turbines and goes back into the river, and there is no large storage dam.
• Indian run-of-river projects on the western rivers:
• Kishanganga, on the Kishanganga (Neelum) river, a Jhelum tributary.
• Ratle, on the Chenab.

• Pakal Dul, on the Marusudar river, a Chenab tributary.

• Treaty in abeyance (April 2025):

• On 22 April 2025, a terror attack at Pahalgam (J&K) killed 25 Indians and one Nepali citizen [5].
• On 23 April 2025, the Cabinet Committee on Security decided that the IWT will be held in abeyance (put on hold) with immediate effect [5].
• It stays on hold until Pakistan "credibly and irrevocably" stops supporting cross-border terrorism [5].

6. Floods in the Indus plains: Punjab 2025

• Punjab floods 2025: the Satluj, Beas and Ravi flooded together in Punjab.
• Very heavy monsoon rain fell over the Himalayan catchments in Himachal Pradesh and J&K.
• Large amounts of water were released from reservoirs, and the rivers overflowed their banks.

• Farmland and villages in Punjab's plains went under water.

• The CWC has no flood-forecasting station in the Indus basin [2]. Early warning for these rivers is therefore weak.

Prelims Hooks

• The Indus rises near the Bokhar Chu glacier in the Kailash range (Tibet), where it is called Singi Khamban. The Satluj rises at Rakas Tal, where it is called Langchen Khambab. Do not mix up the two.
• Panjnad = Jhelum, Chenab, Ravi, Beas, Satluj. The Indus is not one of them. West-to-east order: J–C–R–B–S.
• Largest Indus tributary = Chenab, formed by the Chandra and Bhaga at Tandi (near Keylong, HP).
• Only Panjnad river wholly in India = Beas. It meets the Satluj at Harike.
• Shyok rises from the Rimo glacier. Its tributaries are the Nubra and the Galwan.
• Kabul joins the Indus on the right bank at Attock. The Panjnad joins on the left bank above Mithankot.
• Satluj enters India at Shipki La and leaves its gorge at Rupar. Like the Indus, it is an antecedent river.
• Jhelum: Verinag → Srinagar → Wular lake → joins the Chenab near Jhang. Ravi: Chamba valley → joins the Chenab near Sarai Sidhu.
• Largest state share of the Indian Indus basin = J&K (1,93,762 sq km), then Himachal Pradesh [2].
• IWT 1960: India has full use of the eastern rivers (Ravi, Beas, Satluj). Kishanganga, Ratle and Pakal Dul are on the western rivers [4]. The Chenab Rail Bridge is 359 m high and is the world's highest railway arch bridge [3].

Mains Points

• Antecedent drainage and gorges (GS-I): the Indus and Satluj are older than the Himalaya. As the ranges rose, the rivers kept cutting down. This made deep gorges near Gilgit and between Shipki La and Rupar. These gorges are good sites for hydropower (Bhakra, Kishanganga), but the slopes are steep and landslides are common.
• Water stress in the basin (GS-III): about 87% of usable surface water and about 71% of groundwater in the Indian Indus basin are already used [2]. This is why Punjab–Haryana–Rajasthan canal systems (Bhakra Nangal, Indira Gandhi Canal) and water-sharing disputes matter so much.
• IWT and strategic water use (GS-II/III): with the treaty in abeyance since April 2025 [5], India can push faster on its run-of-river projects on the western rivers. Problems remain: high cost, fragile Himalayan geology, and very little storage.
• Flood risk (GS-III, disasters): heavy monsoon rain in the hill catchments and large releases from dams caused the 2025 Punjab floods on the Satluj, Beas and Ravi. The basin has no CWC flood-forecasting station [2]. Better forecasting and dam-release protocols are needed.