Similar claims of desertifications were also made in the daily Ittefaq on November 23 and 25, 2004, in two articles on the impact of Tipaimukh Dam on Bangladesh claiming that Sylhet area will turn into desert!

In all these cases the writers have failed to understand the difference between diversion of water from the main river (Farakka case) and effect of storage dam for generation of hydro-electricity (like Tipaimukh Dam on the Barak in India or the Kaptai Dam on the Karnafuli in Bangladesh).

Has the Kaptai Dam made the downstream area in Bangladesh a desert? Why then Tipaimukh Dam should make the Sylhet region a desert? Sylhet is not only the highest rainfall area in Bangladesh; the highest rainfall area of the world is just across the border. Let us not misguide the nation and whip up unnecessary anti-Indian feeling.

As far as I remember, India raised the concept of Tipaimukh Dam project in one of the Bangladesh-India meetings prior to the first agreement on the sharing of Ganges water. The project was introduced as one where both the countries can get the benefit. At that time Bangladesh was too much pre-occupied with the sharing of Ganges water and as such the discussion on Tipaimukh Dam did not proceed.

A two-day International Tipaimukh Dam Conference (ITDC-2005) that began on December 30, 2005 at Dhaka has revealed many things. We in Bangladesh had to face serious rehabilitation problem of the people affected by the inundation of Kaptai Lake. India will have to tackle such a situation in the upstream. It is however a matter of great hope that due to the pressure of environmentalists all over the world, rehabilitation of affected people is getting high priority in all major water resources project. The slogan of the World Bank on big projects is now: "Nobody should be worse off due to the project."

It is also understood that India is planning to export this surplus power to Laos, Vietnam, and Cambodia. If this is true, why cannot we get this power from India? This will benefit both India and Bangladesh. India can save the huge investment in power transmission cost while Bangladesh can get cheaper power. Provided of course that other adverse impacts of the project are mitigated to an acceptable limit for Bangladesh.

Let us have a pragmatic approach to the impact of Tipaimukh Dam on Bangladesh. In this connection I would like to touch a few points: a) modification of river flow regime, b) its impact on boro cultivation in the vast haor areas, and c) the flood flows for the water resources engineers, agriculturists, and environmentalists to ponder. Definitely not desertification, rather water logging may be a problem.

• The proposed hydroelectric project will not reduce but will modify the annual flow distribution. What will be exactly the schedule of release of water from the reservoir? This is of serious concern to us. The Surma and the Kushiyara passes through the vast haor area growing only one rice crop annually. With the recession of monsoon, river level drops and allows drainage of the vast low lying haor areas, making the land available for boro cultivation. There is an intricate balance of time-bound drainage for the land to be available for boro cultivation. With the Tipaimukh Dam operational, the river level will be higher in the post-monsoon period and will obstruct timely drainage of the haors and many lands may not be planted because the land may not drain out. A vast area may thus go out of boro production.
• Some of the land drained marginally will be vulnerable to early spring flooding (March-May) due to shorter crop height due to late planting.
• Construction schedule of barrage and the dam is not known. If the barrage is constructed earlier and commissioning of the storage dam needs several more years, then during the intervening period dry season flow of the Surma and Kushiyara will be seriously depleted.
• Schedule of release is important from another point of view. In monsoon areas, storage reservoirs are normally filled up during withdrawal of monsoon in order to maximize hydroelectric production. Late monsoon heavy rain, which is not rare in this area, may cause much more than normal flood downstream in Bangladesh due to extra release from the reservoir for its safety. Bangladesh has experienced such floods a few years back when the districts of Kushtia and Satkhira were flooded due to late monsoon releases from reservoirs on the rightbank tributaries of the Hoogly-Bhagirathi system in India. The same thing may happen in the Sylhet area.
• Average flood height during the monsoon may decrease but operational fault or operation of the dam without taking downstream flooding into consideration is likely to cause higher flooding at times.
• In the event of dam failure due to earthquake or otherwise, there could be serious consequence of downstream flooding.
• Increased agricultural activity and development of agro-based industry in the Cacher Plains may cause increased water pollution in the downstream flow due to increased use of fertilizer and pesticides and effluent from the industries.
• A very substantial part of the sediment may be trapped upstream of the dam. Release of comparatively sediment-free flood flow may initiate riverbed and bank scouring as river will try to establish a new regime of reduced sediment discharge.
• Network of existing submersible flood dike in Bangladesh to protect Boro crop from early spring flood may need redesign and there could be other environmental effect that may need some mitigation measure.

India should therefore sit with Bangladesh to settle these and other related problems and Bangladesh should also show her interest to share the benefit of the project. The project package should have component of mitigation of the adverse impact on Bangladesh and Bangladesh can enter into an agreement with India to purchase cheaper hydro-power and save India for making large investment in transmission system for export of power to Laos, Cambodia, etc. Through a joint study by India and Bangladesh, Tipaimukh Dam project can bring benefit for both India and Bangladesh.

This morning also I have noticed the head-line news in The Daily Star: "Resist Construction of Tipaimukh Dam." I have great respect for the sentiments expressed but would like to assure that dams constructed for generating hydro-electric project in general do not reduce dry season flow downstream, but in case of Bangladesh, it may create the other complications I have already mentioned.

I therefore once again express my strong feeling that properly planned, designed, implemented, and operated, this project can bring great benefit to the people of the area. India should therefore take the people of Bangladesh in confidence.

MA Matin is Retd Director, BWDB.