from India. The entire watershed of the river is the most fertile agricultural zone. The upper course of the river is famous for crops like ginger, medicinal herbs and fruits like oranges, pomegranates etc. The middle course comprises production of tea and corn dominated while the long course is dominated by rice, jute and tobacco. The bamboo and the mat sticks are cultivated in the lower basin. The river enters Bangladesh at Ghoksadanga district to meet the Brahmaputra or the Jamuna. Subansiri River: Subansiri is the largest tributary of Brahmaputra and originates in the Himalayas from the Tibet Autonomous Region of China at an altitude of 5340 m. It flows east and southeast into Arunachal Pradesh of India and then south to the Assam Valley, where it joins the Brahmaputra River in Lakhimpur district. The length of the river Subansiri from its source of origin to the point of confluence with the river Brahmaputra is 520 km. with a drainage basin 32,640 square kilometers. It contributes 7.92 % of the Brahmaputra ' s total flow. Its discharge is huge; maximum observed discharge was 18,799 cubic metres per second. Throughout its journey from the Central Himalayas to the Arunachal foothills, the river Subansiri receives the water discharge from numerous mountainous streams. It is the life line
Newsletter No. 63; IRBMS of the downstream inhabitants. It plays an important role to the distribution of terrestrial as well as aquatic biodiversity, agricultural diversity and socio economic aspects of local communities which live in the downstream of the Subansiri River, whose local economies are linked with the river system and the it’ s associated wetlands( bils).
A large dam is under construction of 2000 MW capacity known as Lower Subansiri Hydroelectric Power Project by NHPC on the Subansiri river close to the Assam-Arunachal Pradesh border town of Gerukamukh in Dhemaji district of Assam. The height of the dam is proposed to be 116 metres and there will be 8 turbines of 250 MW each in the power station. The total downstream floodplain of the river Subansiri from the dam site at Gerukamukh to its confluence with the mighty river Brahmaputra is approximately 130 sq. km. This hydroelectric project can have serious impact on survival of some species that live and depend on the Subansiri river ecosystem. All the systems in the Subansiri River are delicately balanced and interrelated. Therefore, disrupted food chains and other systems will have serious impacts, affecting both the terrestrial and aquatic species. Reservoirs created by the dam can also block animal migrations towards upstream. Besides, the total aquatic habitats will also be destroyed. The downstream areas of the river Subansiri is
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Integrated River Basin Management Society