The principal rivers flowing through the district are, Gumti, Muhuri and Feni. The river Gumti originates from the range connecting the Longtharai and Atharamura. At its source, two rivulates, namely, Kalyansing and Malyansing meet, thereafter it takes the name of Raimacherra till it meets the Sharmacherra. Later it assumes the name Gumti. The River Gumti which is about 135 km. Long runs across the sub-divisions Gandacherra, now under Dhalai District, Amarpur and Udaipur under South Tripura District and Sonamura Sub-Division of West Tripura District. The river Muhuri has its source in the Deotamura range. It is more than 64 km. long and has a catchment area of 1014 sq.km. and it flows westwards through hillocks and plains of Belonia sub-division till it enters Bangladesh.

At the source of river Feni, there are three streams known as the Asslang, the Rangafeni and Taindung, of which the Asslang is the principal channel. The river Feni forms the natural boundary between the South Tripura District and Bangladesh.