Teesta Barrage, Bangladesh

 dam, barrage, bridge

Teesta Barrage project, Bangladesh

Teesta Barrage is located on Teesta river at Duani in Hatibandha upazila in Lalmonirhat district of Bangladesh. The barrage is a 615m long concrete structure fitted with 44 radial gates having a discharge capacity of 12,750 cusec of water. It is used to divert 280 cusec of water for irrigation through a canal taking off on the right bank. The construction of the barrage started in 1979 and that of the irrigation canals in 1984, and was completed in 1997-98.

The idea of irrigation from the Tista was conceived some time in 1935. A preliminary feasibility report of the project was prepared in 1960 by Haigh Zinn and Associates in collaboration with Associated Consulting Engineers. The consultants proposed a barrage on the river at Goddimari for diverting water into the canals for irrigation. Another report was prepared by Binnie and Partners during 1968-70 with a proposal for the barrage to be sited at Dalia. For about 10 years it remained confined to investigation, studies and survey. In the meantime India constructed a barrage across the Teesta at Gazoldoba which is about 100 km upstream of the proposed barrage site in Bangladesh. Engineers of the Bangladesh water development board and experts of BUET (Bangladesh University of Engineering and Technology) jointly reviewed the previous reports and prepared a fresh survey and field investigation. Finally, the actual construction of the barrage was commenced in 1979 at Dalia point of Duani. The barrage was completed in August 1990 with a 110m long Canal Head Regulator to control flow of water into the irrigation canal. Also a silt trap to control entry of sediment in the canal, a 610m long flood bypass for release of flood water in excess of the discharge capacity of the barrage, and a 2,470m long closure dam to divert flow through the barrage were constructed. A flood embankment of about 80 km has also been built to provide flood protection to the adjoining areas. The TBP was designed to provide irrigation water, flood protection and drainage facilities for 749 000 ha of cultivated land. The project was planned to be completed in two phases. Phase 1 was completed in June 1998. The main conveyance system completed under this phase includes 307 km main canals, 1450 km secondary canals, 2735 km tertiary canals and 8000 field outlets. Phase 1 targets irrigation of 111 406 ha, particularly as supplementary irrigation in the monsoon season.

The gross benefited area of the project is 750,000 ha, of which 540,000 ha is irrigable. The project area spreads over seven districts in greater Rangpur, Dinajpur and Bogra. The irrigation canals and water distribution network were developed in two phases. Phase-I has a command area of 182,00 ha with a net irrigable area of 132,000 ha. The remaining area was developed under Phase-II. Irrigation was first provided in 1993. At 1990 prices, the project cost was Tk 8,574 million, making the development cost lowest compared to other irrigation projects in the country. Its cost is about Tk 27,000 per ha. The Teesta Barrage is the largest irrigation project in the country, four times the size of the Ganges-Kobadak irrigation project, 12 times that of the Chandpur Project and 40 times that of the Meghna-Dhonagoda Project.

Water Availability:

According to the feasibility study in 1959, the barrage on the Teesta River was proposed to supply 255 m3/s of water to irrigate 749 000 ha (BWDB 1990). The barrage was designed with a discharge capacity of 12 755m3/s. The highest average flow in the dry season recorded in 2000, accounts for 80.0% of the proposed irrigation requirement and 1.6% of the barrage discharge capacity. Flow is the lowest in February and seldom exceeds 160 m3/s. BWDB (1999) suggests that withdrawal at the Indian barrage upstream reduces the flow.

Teesta faces severe drop in flow:

There is alarming drop in the flow of Teesta water from India into Bangladesh. It has reached a record low from 5,000 to 500 cusec at this time of the year. It is of little surprise that water levels of Teesta have dropped drastically, as obstructions such as dams have been erected on tributaries of Teesta in Sikkim to reduce winter flows coming down the plains. Again, water coming down from Sikkim hills is being diverted by the Gazaldoba barrage in India through a link to the Upper Mahnanda River. While such diversion of water is undoubtedly aiding agriculture in India through irrigating nearly 100,000 hectares of land, it is posing a crisis for the Teesta irrigation project in Lalmonirhat of Bangladesh.

It is imperative that some agreement is reached to assure the minimum amount of water to meet our irrigation needs and preserve our ecology. Experts believe that based on historical water flow data, Bangladesh's share should not fall below 4,500 cusec. That would ensure the sustainability of the river and preserve the biodiversity of areas adjacent to it. However, without the inking of an accord, no verbal commitments are of any avail. We hope that diplomatic efforts will be redoubled to reach such an agreement sooner rather than later since Bangladesh cannot afford any more delay on the issue.