 The Atrai was formerly one of the greatest rivers of north Bengal for it was the main channel by which the waters of the Teesta discharged into the Ganges.In 1787, however, the Teesta broke away from its ancient bed and cut for itself a new and capacious channel by which it found its way into the Brahmaputra.Since then the Atrai has lost its importance and has now few traces of its former greatness.