Published: Thursday, April 4, 2013

Ganges Barrage: Talbaria site is best option

op02THE Farakka Barrage is located a few kilometres upstream, from where a substantial quantity of water is diverted to the Bhagirathi River during dry months. This reduction of flow in the Ganges led to catastrophic damages in the environment in its dependant areas inside Bangladesh.

Before completion of the Farakka Barrage, an interim agreement was concluded on April 18, 1975, allowing minimum 44,000 cusec of water to Bangladesh at the period of diversions. The second agreement, known as the 1st Ganges Water Sharing Treaty, signed on November 5, 1977, ensured minimum 34,500 cusecs of water for five years. After its expiry, two Memorandums of Understanding were concluded in 1982 and 1985. There was no sharing agreement from 1989 to 1996. In 1996, the 2nd Water Sharing Treaty was concluded, which is valid for 30 years, and provides minimum 27,633 cusec of water to Bangladesh during diversions.

Bangladesh plans to build a barrage somewhere between Harding Bridge and Rajbari on the Ganges River. Tippetts Abbett McCarthy Stratton (TAMS), a consultancy firm from New York, proposed this barrage in 1963, at a location 3 km downstream of the Gorai River off-take. The barrage site was changed in 1981, at a location 4 km downstream of the Pakshey Railway (Harding) Bridge, with possibility of reducing its river training cost. But later in 1986, considering possible backwater effects up-to the Indian territory, the site was again shifted, to a far downstream point near Habashpur, Rajbari. In 2002, a study on the Ganges Dependant Area went for a fourth location for the barrage site, near Thakurbari (Shelidah) of Kushtia.

Bangladesh, in the eighties, constructed the Tista Barrage to irrigate a large part of the northern region. With this experience we can construct the Ganges Barrage with our own manpower, skill and technology. Four sites have been selected so far, but they all have weaknesses on the aspects of construction, operation and maintenance, and the benefits gained. I have a proposal for a 5th site near the Gorai off-take. The major aims of the barrage are, (i) to divert water to the Gorai River to fight salinity in the southwestern region, and (ii) to feed the G.K. Project areas, Pabna Project areas for gravity irrigation.

The Hatash Haripur site (1963) is about 3 kilometres downstream of the Gorai off-take. This site would be too far to supply irrigation water to the G.K. Project canals. The Bheramara Bahirchar site (1981) was about 4 kilometres downstream of the Paksey Railway Bridge. To divert water to the Gorai River from this site would need an off-take regulator and a 15 km long link canal to link the Gorai River. Moreover, it would need another barrage at the original off-take of Gorai, like Bhagirathi off-take at Jangipur. However, this site would benefit the G.K. Project by providing irrigation water by gravity.

The Bheramara Bahirchar site was shifted in 1986 on the ground that backwater afflux of the barrage may reach the Indian territory. This was nonsense, as the location of this site was 40 km away from the international border. The Tista Barrage is only 8 km away from the border, where no such problem arises.

The Habashpur, Pangsa site proposed by Halcrow Consultants in 1986 (proposed again by Development Design Consultants in 2012), is about 30 km downstream of the Gorai off-take. Because this site is located far downstream, diversion to the Gorai River will not be possible. The Habashpur, Pangsa site will neither be able to preserve river water during monsoon — because a barrage is never built as a High Dam for storagenor will it be able to irrigate greater Kushtia, Jessore, Khulna, Pabna and Rajshahi district areas it is located far downstream.

The Ganges is the breeding place of hilsa fish from Rajbari to Chapai Nababganj for about 200 km length of the river. A barrage at Habashpur site will obstruct hilsa migration to this spot, causing serious damage to the environment. The Thakurbari, Shelaidah site (2002) is about 10 km downstream of the Gorai off-take. A Ganges Barrage at this site will need protection work of 10 km length from southern bank of the barrage to Gorai Barrage northern bank. As this site is located far from the G.K. Project areas, it would be difficult to supply irrigation there.

Analysing the pros and cons of the so far identified sites,   the Talbaria- Kushtia site for the Ganges Barrage appears to be the best. This site is about 6 km down-stream of Dadapur of Pabna and 3 km downstream of Talbaria, Kushtia on the left bank char lands of the Ganges River. With Talbaria hard point on the right and Dadapur hard point on the left, it becomes a nodal point of the Ganges River. By fixing the barrage site between them, outflanking will not be possible beyond those two points, and will need less bank protection works.

A major advantage of this site is that the barrage will be able to supply water to the G.K. Project, Pabna Project and Faridpur area for irrigation, and to the Gorai River easily by gravity flow. A barrage at this place will allow hilsa migration 30 km upstream of Habashpur, Pangsa site, thus substantially reducing the environmental damage.

The writer is Chairman, Institute of Water & Environment.  Email:minamul@gmail.com