Drainage System of West Bengal: Rivers, Lakes and Wetlands

By Saroj Singh|Updated : February 18th, 2022

Rivers have been fundamental to human settlement throughout the civilizations. They are immensely utilized for irrigation, navigation, and also hydro-power generation. Rivers contribute significantly to a country like India, where agriculture is the primary source of livelihood for the majority of its population.

This article is very much helpful for WBCS, WBPSC, and WBP Exams. Questions are frequently asked from West Bengal Rivers, Lakes, and other water bodies.

Table of Content

West Bengal is regarded as the land of many rivers. The Ganges divides the state into two parts: North and South Bengal. Twenty districts are in North Bengal, and thirteen are in South Bengal. As we have discussed earlier, West Bengal is the only state where the presence of Himalaya as well as a sea coastline is seen, offering wide topographic diversity and intricate drainage network with the fertile deltaic region. 

Drainage System of West Bengal

The rivers of the region in their lower reaches flow through India and Bangladesh and in upper courses through Nepal and Bhutan. West Bengal has perennial and non-perennial streams along with lakes and waterfalls. For the ease, the rivers of West Bengal are broadly classified as:

  1. the rivers of North Bengal: Mahananda, Teesta, Torsa, Jaldhaka, Kaljani and Raidak.
  2. The Ganges and its tributaries:
  3. Rivers of the South (or Sundarbans Region): The south Bengal can further be subdivided into two geographical units taking the Bhagirathi-Hugli river as the demarcating line.
  4. Rarh Bengal is considered as the Western part, and the eastern part is described as deltaic Bengal.

Let us explore them in detail:

Rivers of North Bengal

The North Bengal has been divided into two physiographic units: mountains and plains.  Darjeeling and Jalpaiguri district (extreme north-eastern part) is included in the hilly region.

  • Deep I or V-shaped valleys in mountains and wide-open valleys in plains are formed by the antecedent rivers present there.
  • The rivers here are perennial and are replenished by snow-melt water during summer months.
  • An intricate network drains North Bengal of torrential rivers which carry huge sediment load.
  • The principal rivers of North Bengal are Mahananda, Teesta, Torsa, Jaldhaka, Kaljani and Raidak. These are known to form overlapping depositional lobes representing multi-dated sediment layers.
  • The Teesta is the most significant river of Sikkim and North Bengal.

a. Teesta

This river originates from the Zemu glacier of the Himalayas and makes gorges in its upper course. The river forms the border between West Bengal and Sikkim. It flows through Sikkim, West Bengal and Bangladesh and finally falls into river Jamuna or Brahmaputra near Chilmari of Bangladesh. The western part of the Teesta river is known as Terai.

Note: Floods are widespread in this river, that is why the barrage project has been implemented by which flood can be controlled. However, all streams of North Bengal have been clogged with boulders, pebbles and sand and tend to alter their courses during monsoon months.

Tributaries of Teesta: Rangit, Jaldhaka, Kalijhora, Lish, Gish, Chel Nala and Karola.

b. Jaldhaka river

This river originates from the Bidang lake located in Sikkim Himalayas, drains Southwards through the Jalpaiguri district, and falls into the Jamuna river in Bangladesh. It is one of the major rivers of the Terai-Duar region.

Tributaries of Jaldhaka river: Daina, Birukhola, Bindukhola and Nakshalkhola.

c. Torsa River

This river originates from the Chumbi valley in Tibet and flows into Bhutan. It enters India in Coochbehar district of West Bengal and falls in Jamuna river in Bangladesh. It has two branches, i.e. Chili Torsa and Char Torsa.

The tributaries of Torsa river are Malengi, Bela and Sunjai.

d. Kaljani River

This river originates in Bhutan on the foothills of the Himalayas and flows North to South passing through the district of Alipurduar in West Bengal and falls into the Brahmaputra river after confluence Torsa river.

Tributaries of Kaljani river are: Gadadhar, Cheko and Nenai are some of its tributaries.

e. Raidak River

This river originates from Akungchu peak of Bhutan. It flows through Bhutan, Jalpaiguri and Coochbehar districts of West Bengal and falls in Jamuna river in Bangladesh.

Tributaries of Raidak river are: Dipa is the tributary of Raidak river.

Ganga and its Tributaries

The Ganga river originates from Gomukh which is the melting place of Gangotri glacier in the Himalayas of Uttarakhand and travels down the Northern plains. It is the longest river in West Bengal.

  • Near Dhulain in Murshidabad district, the Ganges divides itself into two branches. One of its subsidiaries flows into Bangladesh as the Padma.
  • The other branch bends and flows Southwards to merge into the Bay of Bengal From Murshidabad to Hooghly, it is known as Bhagirathi, and from Hooghly to the Bay of Bengal, it is known as Hooghly river.
  • In West Bengal, the Northern region of the Ganga is known as Barind.

Bhagirathi-Hoogly River

A dam has been constructed at Tildanga where its mainstream is channelised to Bhagirathi-Hooghly atJangipur barrage inWest Bengal which is the unit of the Farakka barrage.

The principal tributaries are the Mayurakshi, the Ajoy, the Damodar, the Darakeswar, Silai and Kansai.

  • All these rivers originate from uplands of Chotanagpur and adjoining Rarh uplands and flow eastwards or south-eastwards into the Bhagirathi.
  • Upper catchments of all significant tributaries to Bhagirathi and the areas are regionally covered with lateritic and red soil.
  • The increasing sediment load has been the primary cause of the decay of rivers, which are now choked with sand and silt.

Note: From an economical and geographical point of view, Hooghly is the most important river of West Bengal. Kolkata, the capital of West Bengal, lies on the Eastern bank of the Hooghly river. Bhagirathi flows through Murshidabad, Malda, Nadia, while Hooghly flows through the districts of Hooghly, Howrah and 24 Parganas of West Bengal. It flows towards the South and falls into the Bay of Bengal.

Rivers of South Bengal

The tides feed the rivers in the South Bengal, and this region is prominently a delta region. Most of the rivers in this region are distributaries of the Hooghly river. Some principal rivers of the South are Ichamati, Raimangal, Saptamukhi, Malta, Gosaba, Hariabhanga, Thakuran, etc.

The Ganges-Brahmaputra delta, also known as the Sundarban delta or the Bengal delta or the Ganges delta, is situated in Asia where the Ganges and Brahmaputra rivers discharge into the Bay of Bengal. It is the largest delta in the world.

  • Approximately, a two-third portion of this delta is in Bangladesh, and the rest constitutes the state of West Bengal.
  • The Ganges delta is the floodplain of three great rivers-the Ganges, the Brahmaputra and the Meghna.
  • The delta is among the most fertile in the world.

Note: Kolkata and Haldia in India and Mongla and Chittagong in Bangladesh are principal seaports of this delta.

4. Rivers of the Western Plateau

Some principal rivers in the Western part of West Bengal are Ajay, Mayurakshi, Damodar, Rupnarayan, Haldi and Subernarekha.

  • These rivers rise from the Chotanagpur plateau in West and flow towards the South-East to join the Bhagirathi-Hooghly river.
  • These rivers are rainfed rivers as they usually have water during the rainy season.
  • The principal rivers of the Western Plateau are Haldi and Subernarekha rivers.

Some other prominent rivers of West Bengal

Mayurakshi river

  • This river originates from the Trikuta hill of the Chotanagpur plateau. It enters in West Bengal in Birbhum district.
  • This river falls in the Bhagirathi river at Kalna town in Bardhaman district of West Bengal.
  • Its main tributaries are Bakreshwar and Dwarka. Tilpare barrages built on this river.

Damodar River

This river originates from the Khamarpath hill of the Chotanagpur plateau in Bihar and falls in Bhagirathi-PIooghly river at Ulberia town inWest Bengal. This river is also known as the Sorrow of West Bengal as it used to flood many areas of Bardhaman, Hooghly, Howrah and East and West Midnapore districts.

  • Itis the second-longest river of west Bengal.
  • With the Damodar Valley Project, the floods have been controlled.

Its tributaries are Barakar, Konar, Bokaro and Ayar.

Rupnarayan River

This river originates from the foothills in the Chotanagpur plateau and falls in the Hooghly river at Geonkhali town inWest Bengal.

  • This river is known as Dwarakeswar river in Bankura.
  • Mundeswari is the main tributary of this river.

Haldi River

This river originates from the joint flow of river Kangsabati and Keleghai and falls into the Bay of Bengal.

  • Kangsabati river originates from the Chotanagpur plateau and flows through Purulia and East and West Bengal Midnapore districts. Keleghai joins the Kangsabati in East and West Midnapore districts; this combined river is called the Haldiriver.

Subarnarekha River

This river originates from the Ranchi district in the Chotanagpur plateau and flows through the Midnapore district of West Bengal, and then, it enters Odisha. This river falls into the Bay of Bengal.  Kharkai, Sankho, Sapulinala, Rupai and Dulung are some of its tributaries.

Lakes and Wetlands

We know the importance of lakes as an attractive tourist spot, also for some ecological benefits associated with them. They moderate the climate of surroundings, maintain the aquatic ecosystem, add aesthetic value to a place and hence help develop tourism and provide recreation. Some other benefits are as follows:

  • Lakes help in regulating the flow of a river
  • Lakes prevent flooding during heavy rainfall and maintain even flow during dry summers.
  • Lakes can also be used for deriving hydel power.

West Bengal has many lakes located in various corners of the State, making it an essential tourist destination. Some of the famous lakes include:

  1. East Calcutta Wetlands

Designated as a "Wetland of International Importance" under the Ramsar Convention on 19 August 2002.

  • These wetlands are a complex of natural and human-made wetlands lying east of the city of Calcutta (Kolkata), in West Bengal in India. 
  • The wetlands are used to treat Kolkata's sewage, and the nutrients contained in the wastewater sustaining fish farms and agriculture.
  • The wetlands include salt marshes and salt meadows, as well as sewage farms and settling ponds.
  • Sewage fed aquaculture based artificial wetland, like East Kolkata Wetland (EKW), is a robust example of potential carbon sink and spin-off. 
  1. Rabindra Sarovar Lake

Previously regarded as Dhakuria Lake, it is an artificial lake in South Kolkata. Created in May 1958, by excavation in a swampy area and renamed after the noted Bengali writer and Nobel Laureate, Rabindranath Tagore.

  • It is surrounded by a 50-hectare area which has been developed by the Kolkata Improvement Trust with parks, gardens and extensive tree plantation and is used for intensive sport, recreational and cultural activities.
  • Presently the lake is under environmental degradation due to rising water pollution because of tourist inflow and inhabitation.
  • To preserve the lake has recently been included under the National Lake Conservation Plan by the Ministry of Environment and Forests, Government of India. In this regard, an extensive tree plantation programme has been carried out.
  1. Mirik Lake

Located in the Kurseong sub-division of Darjeeling district, it was created in 1979 by damming the stream which feeds the river Mechi. A dense coniferous forest lies on the South-West of the lake whereas the hills on the Northern side experience extensive erosion.

  • The highest point in the vicinity is Boker Monastery.
  • The lake is 52 km (32 mi) northwest of Siliguri city and 49 km (30 mi) south-southwest of Darjeeling town.
  1. JorePokhri

Also regarded as a twin lake after which the lake has been named as ‘JorePokhri’. Jore means two in Nepali and Pokhri means Lake.  Jore Pokhari is a small village on a hilltop which is almost 20 kilometers away from Darjeeling town.  

  • There is a wildlife sanctuary named – Jore Pokhri Wildlife Sanctuary in Darjeeling District of West Bengal.
  • The Sanctuary is the habitat of some high-altitude animals like Himalayan Salamander, locally known as 'Gora'. Bird species are also prominent here.
  1. Rasikbeel Wetland

It is situated in Cooch Behar district near the town of Tufanganj. It was identified as a wetland in 2004. It is home to many types of birds.

  • This lake is an excellent attraction to many birds which make nests in the trees around the lake. Various species of birds are seen here such as- Lesser Whistling Teal, Common Teal; White-eyed pochard, Red Crested pochard, Shoveler, Pintail, Wigeon duck, Gray-headed Lapwing, Northern Lapwing, Pied Kingfisher, Stork-billed Kingfisher, Small blue kingfisher, Little Cormorant, Large Cormorant, Gadwall etc.
  • There are a deer park and a crocodile rehabilitation center by the side of the lake. Also, there is a leopard house, a python house, Aviary & a Tortoise rescue center.
  1. Santragachhi Jheel

It is a large lake located next to the Santragachi railway station. This lake attracts a large number of migratory birds in the winter months, particularly in December and January.

  • The number has increased in recent years, as migratory birds have started to avoid destinations like the lakes in Alipore Zoo, Kolkata.
  • Fauna: Birds likes sarus crane from North America and Australia, gadwall, northern shoveller, northern pintail, garganey from north of the Himalayas, and many other local migratory birds such as cotton pygmy goose, and knob-billed duck are spotted here during this season.
  • The lesser whistling duck is the most dominant species visible here.
  1. Senchal lake

 Located 10 km to the south-east of Darjeeling, the lake is the main reservoir of potable water for the town of Darjeeling, India.

  • Senchal is a favorite picnic spot, and the hill also has one of the highest golf courses in the world.
  • This lake also serves as the water reservoir for the supply of water to Darjeeling.
  • A tourist lodge at Senchal provides accommodation to tourists. This lake is a part of the Senchal Wildlife Sanctuary.
  1. Bhangzang Salamander Lake

It is located at a distance of 14 km from Kurseong sub-division in Darjeeling district. It's a beautiful green-tinged lake that shelters the rarest and most endangered species of salamanders, a species under threat of extinction.

  • Talberia Lake This lake is situated in the outskirts of Jhili Mili in West Bengal.
  • Itis situated about 85 km from Bankura district of West Bengal.
  • The lake is created by rainwater pouring into a glade (an open space in a forest). It is a famous picnic spot also.
  1. Sagardighi Lake

It is situated in the heart of Murshidabad. It is surrounded by the age-old royal heritage buildings on four sides of the rectangular lake. Sagardighi is also famous for a large number of migratory birds that assemble in the lake each year.

Important Wetlands of West Bengal

Wetlands are areas of marshy land such as mangroves, lakes, floodplains, marshes, and flooded forests that contain both aquatic and terrestrial life. The National Wetland Conservation Programme recognises wetlands. An international organization 'Ramsar' also identifies the wetlands which are of global importance.

In West Bengal, six wetlands are identified by the National Wetland Conservation Programme and one Ramsar site. They are as follows:

1. AhiranJhil Wetland

It is located in Murshidabad district. Surplus water from Bhagirathi water gets deposited in this area to create a marshy wetland. It was identified as a wetland in2004.

2. East Kolkata Wetland

It is located in Kolkata and spread over an area of 125 sq km. It is a wetland site of international importance and was included as a Ramsar site in 2002.

3. Santragachi Wetland

It Is situated in Howrah as a wetland in2005. Surplus water from the Hooghly river created the lake which is now a famous place for migratory birds in winters.

4. Sundarbans Wetland

India has designated Sundarban Wetland as a Wetland of International Importance and is a Ramsar site. Located within the largest mangrove forest in the world, the Sunderbans encompasses hundreds of islands and a maze of rivers, rivulets and creeks in the delta of the River Ganges and Brahmaputra on the Bay of Bengal in India and Bangladesh.

5. Patlakhawa Rasomati

It is located in CoochBehar district and identified% wetland site in 2008. This wetland is along the Torsa River.

Waterfalls in West Bengal

Waterfalls of West Bengal are located in the northern part due to the presence of high mountains. The waterfalls of west Bengal attract a large number of tourists around a year from all corners of India and abroad. Some of the famous waterfalls of West Bengal are mentioned as follows:

6. Changey Waterfall

This waterfall is situated 34 km from Kalimpong, North of West Bengal and very close to the border of Sikkim. It is located in Laval, Darjeelinÿ and makes a good picnic spot in the natural wilderness of this place.

7. Whistle Khola

It is located in Kurseong, Darjeeling. This waterfall is the most famous site among tourists who visit it mostly as a picnic spot. The waterfall was named Whistle Khola Because the Toy Train passes through the front of this waterfall while blowing a loud whistle at that spot.


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