Brahamaputra Basin

Brahamaputra Basin
3.2.4 Command area and canals network
Canals are man-made channels for conveyance of water. When the water is to be transported across
landscape to deliver the water to the respective command areas by canal network, construction of
various irrigation structures are necessary to negotiate terrain including drains, road, rail lines.
Important Irrigation structures are Regulators, Bridge, Aqueduct / Syphon Aqueduct, Super passage /
Syphon, Level crossing / Inlets and Outlets, and Other Cross drainage Structures. Distributary head
regulator controls the supply to an off taking channel from the parent channel.
In Brahmaputra Basin there are few completed and ongoing major irrigation projects. But, the canal
network is not very much extensive in this basin (Map 12). Unlike other states of India, irrigation was
hardly practiced for agricultural production in the north-eastern region. In the mid sixties, a few
irrigation projects were developed in Assam. There is no shortage of water for irrigation.But due to
limitations of topography and frequency of flood in lower reaches of the basin large scale irrigation is
not feasible in Arunachal Pradesh and Arrasm. However due to hilly terrain, the drainage of water is
very fast thus causing water stress during dry spell. Surface water resources are tapped in this region
either by diversion structures or by pumping for irrigation.
As per the India WRIS database, there are 25 major & medium command areas in this basin, out of
which 7 are major and 18 are medium commands. Teesta Barrage (Phase-I, St.I, Sub Stage I Irrigation
Project), Dhansiri Irrigation Project, Champamati Irrigation Project, Integrated Kallong Irrigation
Project, Bordikarai Irrigation Project, Jamuna Irrigation Project, are those major projects having
considerable command area falling within the Brahmaputra Basin. Majority of the commands are
falling in the lower Brahmaputra Sub basin. Only 3 ongoing medium command areas namely Dzuzza
command of Nagaland, Buridehing and Rangma of Assam are falling in the upper Brahmaputra sub
basin.
Teesta Barrage (Phase-I, St.I, Sub Stage I) is an ongoing major Irrigation Project of West Bengal
havinga large command area falling in both the Brahmaputra and Ganga Basin. Teesta Mahananda
Link Canal off take from the Mahananda Barrage, Teesta Jaldhaka Main Canal off take from Teesta
Barrage and their minor and distributaries irrigate the Jalpaiguri and Kochbihar areas of
Brahmaputra Basin. The Dhansiri Irrigation project has irrigating the Udalguri and Darrang districts of
Assam. Dhansiri R.B.C originating from Dhansiri Barrage and it’s minor and distributaries have
irrigated a command area of 78.86 Th.ha. The Champamati Irrigation project has command area of
39.42 Th.ha falling in Kokrajhar and the Chirang districts of Assam. Right Bank and the Left Bank
canal off take from the Barrage across river Champamati have irrigating the Kokrajhar and Sirang
districts respectively. Bordikarai Irrigation Project has command area of 28.666 Th.ha irrigating the
Sunitpur district of Assam. Jamuna Irrigation Project is the completed major project of Assam
irrigating Sonitpur district with a command area 28.13 Th.ha. The Ultimate Iirrigation Potential (UIP)
and Culturable Command Area (CCA) of all the major and medium irrigation projects of Brahmaputra
basin are listed in Annexure IV: C.
A study was carried out jointly by CWC & ISRO to assess the existing status of the irrigation
commands. IRS P4 LISS III data of two different seasons namely, pre monsoon (2005) and post
monsoon (2004) were used for delineation of waterlogged and salt affected areas of major and
medium irrigation commands of Brahmaputra basin. Total waterlogged area in this basin was
2243.13 ha.
www.india-wris.nrsc.gov.in 43