Tributaries of the Ganga: Yamuna, the Peninsular feeders and the Himalayan left-bank rivers

Detail

1. How the Ganga gets its water: two sets of tributaries

• A tributary is a river that joins a bigger river and adds its water to it.
• The Ganga gets water from two sides:
• Left bank (north side): snow-fed Himalayan rivers. They flow all year. They carry a lot of silt and often change course.

• Right bank (south side): rain-fed rivers from the Peninsular plateau. Their flow is high in the monsoon and low in summer.

• The Yamuna is a special case. It is Himalayan at its source, but most of its own tributaries come from the Peninsular plateau.

Feature	Himalayan left-bank rivers	Peninsular right-bank feeders
Source of water	Glaciers and snow, plus monsoon rain	Monsoon rain only
Flow	All year (perennial)	Seasonal; low in the dry season
Valleys	Deep gorges in the mountains	Old, wide and shallow; ravines and rift valleys in some places
Examples	Ramganga, Ghaghara, Sarda, Gandak, Kosi, Mahananda	Chambal, Betwa, Ken, Son, Damodar

2. Yamuna river

• Status: the westernmost and longest tributary of the Ganga.
• Source: the Yamunotri glacier, on the western slopes of the Banderpunch range (6,316 m) in the Garhwal Himalaya, Uttarakhand.
• Mouth: it joins the Ganga at Prayag (Prayagraj), Uttar Pradesh.
• Right-bank tributaries (from the Peninsular plateau): Chambal, Sind, Betwa, Ken.
• Left-bank tributaries: Hindan, Rind, Sengar, Varuna.
• Canals fed by the Yamuna:
• Western Yamuna canal (Haryana side)
• Eastern Yamuna canal (Uttar Pradesh side)

• Agra canal

• States drained: Uttarakhand, Himachal Pradesh, Haryana, Delhi, Uttar Pradesh.

• Exam point: the Yamuna's source is Himalayan, but its large right-bank feeders are Peninsular. So the Yamuna links the two drainage systems.

3. The Peninsular feeders

3.1 Chambal river

• Source: near Mhow on the Malwa plateau, Madhya Pradesh.
• Course:
• It flows north, which is unusual for a Peninsular river.
• It cuts a gorge (a narrow, deep valley with steep sides) upstream of Kota, Rajasthan.

• It then flows past Bundi, Sawai Madhopur and Dholpur and joins the Yamuna.

• Dams on the gorge section:

• Gandhi Sagar dam (Madhya Pradesh)

• Downstream: Rana Pratap Sagar and Jawahar Sagar dams, and the Kota barrage

• Chambal ravines (badland topography):

• Badland means land cut into a maze of deep gullies by running water. It can hardly be farmed.
• Cause: the soil along the river is soft alluvium with little plant cover. Heavy monsoon showers fall on it.
• Process: water running off the land cuts small rills. The rills deepen into gullies, and the gullies join into deep ravines along the river.

• Result: the ravine belt of the Chambal valley in Madhya Pradesh, Rajasthan and Uttar Pradesh. In world geography, the Badlands of South Dakota (USA) are the classic example.

• National Chambal Sanctuary:

• About 600 km of the Chambal, from Jawahar Sagar dam to Panchanda, has been protected since 1978 to save the gharial (Gavialis gangeticus), a fish-eating crocodile with a long, thin snout [6]. The date is often given as 1979.
• It covers three states: Madhya Pradesh, Rajasthan and Uttar Pradesh [6][7].
• It includes a strip 1,000 m wide on each bank [7].
• It has the world's largest population of gharials and is the species' last refuge [6].
• Other species here include the mugger crocodile, freshwater turtles, the otter and the Gangetic dolphin, plus over 300 bird species [6].

3.2 Betwa and Ken rivers

• Source: the Vindhyan region, Madhya Pradesh.
• Region drained: Bundelkhand, a dry, drought-prone area in Madhya Pradesh and Uttar Pradesh.
• Both are right-bank tributaries of the Yamuna.
• Ken–Betwa Link Project (KBLP):
• What it is: India's first project under the national river-linking plan. It moves surplus water from the Ken to the Betwa [2][3].
• Approval: the Union Cabinet approved it in December 2021. Total cost is ₹44,605 crore, with central support of ₹39,317 crore (₹36,290 crore grant + ₹3,027 crore loan) [2].
• Main parts: the Daudhan dam on the Ken, a canal linking the two rivers, the Lower Orr Project, the Kotha barrage and the Bina Complex multipurpose project [2][3].
• Daudhan dam: 96.7 m high, in Panna and Chhatarpur districts, Madhya Pradesh, about 40 km from Khajuraho [3].
• Benefits planned: irrigation of 10.62 lakh ha a year, drinking water for about 62 lakh people, 103 MW of hydropower and 27 MW of solar power [2][3].
• Status: foundation stone laid on 25 December 2024. The dam is being built, and canal work has not yet begun. Target completion is 2030 [3].

3.3 Son river

• Source: the Amarkantak plateau (Madhya Pradesh–Chhattisgarh border).
• Status: a large south-bank (right-bank) tributary that flows straight into the Ganga, not into the Yamuna.
• Course:
• It forms waterfalls where it drops off the edge of the plateau.
• It joins the Ganga near Arrah, west of Patna, in Bihar.

3.4 Damodar river

• Location: the eastern edge of the Chotanagpur plateau (Jharkhand), flowing into West Bengal.
• Rift valley:
• A rift valley is a long, low valley that forms when a strip of land sinks between two parallel faults (cracks in the Earth's crust).
• Cause: forces in the crust pull or crack the rock.
• Process: the block between the faults sinks.
• Result: a long, trough-shaped valley. The river then follows this valley.
• In India: the Damodar, Narmada and Tapi flow in rift valleys. In the world: the East African Rift Valley is the best-known example.

• Resource link: the Damodar rift valley holds India's Gondwana coal fields (Jharia, Raniganj, Bokaro). This is why the valley is a heavy-industry belt.

• Mouth: it joins the Hugli (the Ganga's distributary in West Bengal).

• Main tributary: the Barakar.
• "Sorrow of Bengal": the Damodar was given this name because of its frequent, damaging floods in West Bengal.
• Damodar Valley Corporation (DVC):
• Law: created by the DVC Act, 1948, enacted on 27 March 1948. It covered the provinces of Bihar and West Bengal (the Bihar part is now Jharkhand) [4].
• Model: the Tennessee Valley Authority (TVA) of the USA, a single body that develops a whole river valley.
• Duties under the Act: irrigation, water supply and drainage; producing and supplying electricity (both hydel and thermal); and flood control on the Damodar and its tributaries [4].
• Four multipurpose dams: Tilaiya, Konar, Maithon and Panchet Hill [5].
• Outputs: flood control, hydroelectricity, coal-fired thermal power, irrigation of about 3,85,000 ha, mainly in West Bengal, plus afforestation and fish breeding [5].

4. Himalayan left-bank rivers (west to east)

Order to remember: Ramganga → Ghaghara (with Sarda) → Gandak → Kosi → Mahananda

4.1 Ramganga

• Source: the Garhwal hills near Gairsain, Uttarakhand. It is a small river.
• Course: after crossing the Shiwalik range it turns south-west. It enters the plains near Najibabad.
• Mouth: it joins the Ganga near Kannauj, Uttar Pradesh.

4.2 Ghaghara river

• Source: the Mapchachungo glaciers (Tibet).
• Course:
• In the mountains it receives the Tila, Seti and Beri.
• It then cuts a deep gorge at Shishapani.

• In the plains it receives the Sarda.

• Mouth: it joins the Ganga at Chhapra, Bihar.

4.3 Sarda (Saryu) river

• Source: the Milam glacier in the Nepal Himalaya, where it is called the Goriganga.
• Names along the course: along the India–Nepal border it is called the Kali or Chauk (also Mahakali).
• Mouth: it joins the Ghaghara. So it is a tributary of a tributary of the Ganga.
• Mahakali Treaty (India–Nepal):
• Signed in February 1996 [8].
• It covers joint development of the Mahakali, including the Sarada barrage, the Tanakpur barrage and the Pancheshwar project [8].
• Water share from the Sarada barrage: Nepal gets 28.35 m³/s in the wet season (15 May–15 October) and 4.25 m³/s in the dry season (16 October–14 May) [8].
• Tanakpur power station: installed capacity 120 MW. Nepal gets 70 million kWh of power a year free of cost [8].
• Pancheshwar Multipurpose Project: a planned 5,600 MW project to be built jointly [8].
• Validity: 75 years from the date it came into force [8].

4.4 Gandak river

• Formation: two streams in Nepal, the Kaligandak and the Trishulganga. They rise between the Dhaulagiri and Everest ranges.
• Entry into India: the plain of Champaran district, Bihar.
• Mouth: it joins the Ganga at Sonpur, near Patna.

4.5 Kosi river

• Antecedent river:
• An antecedent river is one that is older than the mountains it crosses.
• Cause: the river was already flowing before the Himalaya rose.
• Process: as the land slowly rose, the river kept cutting down into it at the same speed.

• Result: a deep gorge right across the range. Other Indian examples are the Indus, Sutlej and Brahmaputra. The Arun (the Kosi's main stream) is a classic example.

• Main stream: the Arun, which rises north of Mount Everest in Tibet.

• Formation of the Sapt Kosi: after crossing the Central Himalaya in Nepal, the Arun is joined by:
• the Son Kosi from the west
• the Tamur Kosi from the east

• Together they form the Sapt Kosi ("seven Kosis").

• Exam trap: the Kosi is called the "sorrow of Bihar" because of its floods and frequent changes of course. The Damodar is the "sorrow of Bengal". Do not mix them up.

4.6 Mahananda river

• Source: the Darjiling hills, West Bengal.
• Status: the last left-bank tributary of the Ganga. It joins in West Bengal.

5. Quick reference table: origin and mouth

River	Bank	Origin	Joins	Joining point
Yamuna	Right (westernmost)	Yamunotri glacier, Banderpunch	Ganga	Prayagraj
Chambal	Right (of Yamuna)	Near Mhow, Malwa plateau	Yamuna	Beyond Dholpur
Betwa, Ken	Right (of Yamuna)	Vindhyan region	Yamuna	Bundelkhand
Son	Right	Amarkantak	Ganga	Near Arrah, west of Patna
Damodar	Right	Chotanagpur (rift valley)	Hugli	West Bengal
Ramganga	Left	Near Gairsain	Ganga	Near Kannauj
Ghaghara	Left	Mapchachungo glaciers	Ganga	Chhapra
Sarda	Left (of Ghaghara)	Milam glacier (as Goriganga)	Ghaghara	Plains of UP
Gandak	Left	Nepal, between Dhaulagiri and Everest	Ganga	Sonpur, near Patna
Kosi	Left	Arun, north of Everest (Tibet)	Ganga	Bihar
Mahananda	Left (last)	Darjiling hills	Ganga	West Bengal

Prelims Hooks

• Yamuna rises in the Yamunotri glacier on the Banderpunch range (6,316 m) and joins the Ganga at Prayagraj. It is the westernmost and longest Ganga tributary.
• Trap: the Hindan, Rind, Sengar and Varuna are left-bank tributaries of the Yamuna. The Chambal, Sind, Betwa and Ken are right-bank tributaries.
• Chambal: rises near Mhow (Malwa) and flows north. Its dams from upstream to downstream are Gandhi Sagar → Rana Pratap Sagar → Jawahar Sagar → Kota barrage. It is known for its badland ravines.
• National Chambal Sanctuary: a tri-state sanctuary (MP, Rajasthan, UP) covering about 600 km of river from Jawahar Sagar to Panchanda. It holds the world's largest gharial population [6][7].
• Ken–Betwa link: Daudhan dam (96.7 m) is on the Ken, in Panna–Chhatarpur, Madhya Pradesh. Water flows from the Ken to the Betwa. The Cabinet approved it in December 2021 at a cost of ₹44,605 crore [2][3].
• Damodar: flows in a rift valley, its main tributary is the Barakar, and it is the "sorrow of Bengal". The DVC Act, 1948 was modelled on the TVA (USA). Its dams are Tilaiya, Konar, Maithon and Panchet [4][5].
• Joining points (west to east): Ramganga near Kannauj → Ghaghara at Chhapra → Gandak at Sonpur → Mahananda (last) in West Bengal.
• Sarda: rises in the Milam glacier as the Goriganga. It is called the Kali/Chauk on the India–Nepal border and is a tributary of the Ghaghara, not of the Ganga directly. Mahakali Treaty: 1996, Pancheshwar 5,600 MW [8].
• Kosi: an antecedent river. Its main stream, the Arun, rises north of Everest. Son Kosi (west) + Tamur Kosi (east) → Sapt Kosi.
• Son: rises at Amarkantak and joins the Ganga near Arrah. It is a direct right-bank tributary of the Ganga, not of the Yamuna.

Mains Points

• Flood problem of the Himalayan left-bank rivers (GS-I/GS-III):
• Young mountains erode easily and the rivers carry heavy silt.
• When they reach the flat plain, the silt settles and raises the riverbed.
• So the rivers spill over and shift course. The Kosi in Bihar is the worst case.

• Responses: embankments, and river-basin agreements with Nepal such as the Mahakali Treaty, 1996 [8].

• River-valley development model (GS-III):

• The DVC (1948) copied the US TVA: one body manages the whole valley.
• Through dams, thermal power and irrigation, it tamed the "sorrow of Bengal" [4][5].

• It shows both the strengths and the limits of multipurpose projects.

• Interlinking of rivers for drought-prone Bundelkhand (GS-III):

• The Ken–Betwa link promises 10.62 lakh ha of irrigation and drinking water for 62 lakh people [2][3].

• Concerns to discuss: forest and wildlife loss around the Daudhan dam site in Panna district, displacement of people, and whether the Ken really has "surplus" water.

• Land degradation and biodiversity in the Chambal valley (GS-I/GS-III):

• Badland ravines cause loss of farmland. Reclaiming them needs gully plugging, afforestation and better land management.
• The same river supports the world's largest gharial population. So development (dams, sand mining) must be balanced with conservation [6].