Major Rivers in West Bengal
Major rivers in West Bengal are the Bhagirathi-Hugli, the Mahananda, the Tista, and the Jaldhaka. Further, There are East and South-East flowing rivers.
The Bhagirathi-Hugli: The southward flowing rivers are mostly snow-fed. During rainy season they flow in spate. The Bhagirathi-Hugli is the supreme river of West Bengal. The Bhagirathi-Hugli takes off from the Ganga below Farakka. The present off-take point is near Geria at Biswanathpur. It flows southward in the name of Bhagirathi. Below Nadia, it flows in the name of Hugli River.
The Mahananda: Rising from near Mahaldhiram of the Ghum range of the Darjeeling district, the Mahananda river flows southward through the North Bengal. The Mahananda is the longest river in North Bengal. But it flows to a considerable length through the State of Bihar. The river is fairly deep and navigable. It receives on its left bank tributaries such as the Nagar, the Tangan and the Punarbhaba, and on its right bank the Kalindi, Balasan and Mechi.
The Tista: The Tista (or Teesta) is the largest river of the North Bengal. It is the combined streams of the three rivers of Sikkim which rise from the tongues of the Kangse glacier. It has formed southward drainage. The Tista creates flood almost every year during rainy season. A dam has been constructed on this river in the Tarai region to control flood and to generate hydel power. Ultimately Tista enters in Bangladesh.
The Jaldhaka: The Jaldhaka drains southward through the Jalpaiguri district. A number of mountainous streams, locally called khola join the Jaldhaka. The Daina, the Bindukhola, the Birukhola, the Naksalkhola, etc. are its important tributaries. During the rainy season the Jaldhaka flows in spate. A dam has been constructed on the river at Bindu to arrest flood and to generate hydel power.
East / South-Eastward Flowing Rivers of West Bengal: The east and south-east flowing rivers have had their origin on the Chhotanagpur plateau. They are all rain-fed and consequently are mere trickles during the greater part of the year. As their beds are heavily silted, they flow in spate during rainy season. The Bansloi, the Pagla, the Brahmani, the Dwaraka, the Mayurakshi (Mor), the Bakreswar, the Ajoy and the Damodar are the rivers of the northern part of the Rarh. To the south of the Damodar are the Dwarakeswar, the Silai (Silabati), the Rupnarayan (formed by union of the Dwarakeswar and the Silai), the Kasai (Kangsabati) and the Haldi (formed by union of the Keleghai and the Kasai).
Landward / Bay ward Rivers of West Bengal: Matla, Bartala, Saptamukhi, Gosaba and the like distributaries of the Bhagirathi-Hugli River are tide-fed. Hence called tidal rivers. They are fed by the tides. At high tides, they overflow. These rivers experience flood current which is the landward or incoming current that accompanies high tide and the outgoing ebb current which is the Bay ward or outgoing current that accompanies ebb tide. During each high tide, strong tidal current occurs. During each ebb tide, the river flow Bay ward and make their beds muddy. Thus these rivers shift their direction of flow twice daily (lunar day) to the extent of 180°.