The Jamuna River (Bengali: যমুনা Jomuna) is one of the three main rivers of Bangladesh. It is the main distributary channel of the Brahmaputra River as it flows from India to Bangladesh. The Jamuna flows south and joins the Padma River (Pôdda), near Goalundo Ghat, before meeting the Meghna River near Chandpur. It then flows into the Bay of Bengal as the Meghna River.
The Brahmaputra-Jamuna is a classic example of a braided river and is highly susceptible to channel migration and avulsion. It is characterised by a network of interlacing channels with numerous sandbars enclosed between them. The sandbars, known in Bengali as chars, do not occupy a permanent position. The river deposits them in one year, very often to be destroyed later, and redeposits them in the next rainy season. The process of deposit erosion and redeposition has been going on continuously, making it difficult to precisely demarcate the boundary between the district of Pabna on one side and the district of Mymensingh Tangail and Dhaka on the other. The breaking of a char or the emergence of a new one is also a cause of much violence and litigation. It is the National river of Bangladesh.
In Bangladesh, the Brahmaputra is joined by the Teesta River (or Tista), one of its largest tributaries. The Teesta earlier ran due south from Jalpaiguri in three channels, namely, the Karatoya to the east, the Punarbhaba in the west and the Atrai in the centre. The three channels possibly gave the name to the river as Trisrota "possessed of three streams" which has been shortened and corrupted to Teesta. Of these three, the Punarbhaba joined the Mahananda. The Atrai passing through a vast marshy area known as Chalan Beel joined the Karatoya and the united stream joined the Padma (Ganges) near Jafarganj. In the destructive floods of 1787, the Teesta river forsook its old channel and rushing south-east it joined the Brahmaputra.