Brahmaputra

In Bihar, the Kosi has long come to be lamenied as a " River of Sor- row ". So is Brahmaputra in Assam. It is not widely known that the Tista in northern West Bengal is earning a similar reputation. Rivers form natural boundaries between these three States. Sankosh forms the boundary between Jalpaigun in West Bengal and Goalpara in Assam. For a certain length, Mahananda forms the boundary between West, Bengal and Bihar. And the irughty Padma separates the two Bengals.

Reference: http://www.epw.in/system/files/pdf/1954_6/35/rivers_of_sorrow.pdf

Damodar