The Jaldhaka River (Pron:/ˌdʒælˈdɑːkə/) (), also known as Dichu River in earlier times, is a trans-boundary river with a length of 192 kilometres that originates from the Kupup or Bitang Lake in southeastern Sikkim in the eastern Himalayas and flows through Bhutan and the Kalimpong, Jalpaiguri and Cooch Behar districts of West Bengal, India. At that point the river enters Bangladesh through the Lalmonirhat District and then joins with the Dharla River until the Dharla debouches into the Brahmaputra River near the Kurigram District. Due to the river's wandering over several international borders, only a small length of the river lies within Bangladesh.