Nameri is criss crossed with streams and rivers across its length and breadth. Two major rivers, Jiabhoreli and Bordikorai flank the NTR core area on the western and eastern side respectively. The origin of Jia-bhoreli river, also known as Kameng in Arunachal Pradesh is attributed to the glacial lake below the snow capped Gori Chen mountain on the India-Tibet border. Being snow fed river, water flows in Jia-bhoreli river throughout the year. Due to its perennial nature, the river acts as main source of water for wildlife during the peak winter months when water availability in the northern part of the reserve becomes scarce.

(Meandering Upper Dikri river in Nameri )

Apart from being the source of water for the wildlife, the river also acts as a natural barrier for the core area on the the western side. However, the same is not the case with respect to Bordikorai river that flows on the eastern front of the tiger reserve.

Although during rainy season the water level in Bordikorai is fairly high enough to act as a natural barrier, the water level recedes rapidly during winter months. Both the rivers merge together down south near Bhoreli bridge and joins River Brahmaputra to the west of Kolia bhomora bridge, near Tezpur

Other streams/rivers that flow within the tiger reserve from north to south are Digi, Dinai, Nameri, Doigrung, Upper Dikri, Khari, Dihaipur nala, Bogijuli nala and Koilajuli nala. The catchment of all these rivers lies in Arunachal Pradesh. Most of these streams/ rivers, though perennial in nature, tend to dry up during winter months mainly in the upper reaches of the reserve because of highly porous and gravelly sub soil that facilitates subsurface movement of water.