Sharing Teesta’s a murky business

Relations between Bangladesh and India have taken a contentious turn on the issue of sharing water from the Teesta river that flows through Sikkim and the northern parts of West Bengal to Bangladesh. Bangladesh wants 50 per cent of the Teesta’s waters during the dry season between December and May to satisfy its irrigation and fishery needs.

Quite like the Farakka, this too has emerged on two levels, as domestic politics and international gamesmanship. Even as the prime ministers of the two nations are intent on signing a treaty on sharing the Teesta, West Bengal’s chief minister, Mamata Banerjee, offers an alternative: water from three different North Bengal rivers, namely, the Torsa, the Raidak and the Jaldhaka. Recently, she mentioned another rivulet known as the Aatreyi.

Her position is based on the premise that there is not adequate water in the Teesta, according to excerpts published in an article in thethirdpole.net on April 14, 2017, from a recently prepared internal report of West Bengal that is not in public domain.

To quote from the excerpt: “Two barrages on Teesta, at about 100 km from each other, in India and Bangladesh were planned to cater (to) irrigation in more than 16 lakh (1.6 million) hectares of land together; around 9.2 lakh (920,000) hectares in (the) state of West Bengal in India and 7.5 lakh (750,000) hectares in Bangladesh. According to a rough calculation, such a scale of irrigation for boro crop (dry season paddy) will require around 1600 cumec (cubic metre per second) of water; while through much of the dry period the river hardly has 100 cumec of water, i.e. one sixteenth of total water requirement in (the) two countries.”

The excerpt raises more questions than it affords clarity, being in clear non-conformity with scientific knowledge of river science and agronomic arithmetic. While considering crop-water requirements and existing cropping patterns, we need volumetric measures to reach at numerical figures on water requirements. Weird as it may seem, the measurements in the excerpt are given in ‘cumec’ or ‘cubic metre per second’, which is essentially the unit of flow in the channel, and not volume. This brings to the fore an important concern: How far is this data reliable? What is the source of such an estimate?

Further, the obvious question that arises is: Where has the remaining 94 per cent of the water gone? Essentially, the hydro power projects in upstream Sikkim are supposedly based on run-of-the-river technology, without diversionary mechanisms. Further downstream, the Teesta Barrage Project (TBP) at Gajoldoba in Jalpaiguri district, West Bengal, has been blamed for the disappearing waters further downstream. Conceived as a multipurpose project in the aftermath of the massive floods in Jalpaiguri in 1968, the TBP was planned for flood control, hydro power and irrigation in North Bengal.

It is proclaimed that though TBP has contributed to flood control to an extent, there has been much less success towards increasing the areas under irrigation in the lower command area and the flow in the downstream nation of Bangladesh has diminished. Flood control seems to have been thought of more from the perspective of channelising ‘surplus’ water through other means such as the Teesta-Mahananda link canal. The Mahananda channel, by itself, cannot withstand the huge amount of water that flows through Teesta, which reinforces of the question of the lost water.

The very emergence of the TBP is rooted in a reductionist engineering thinking of defining water as a stock of resource without any consideration of sediments, aquatic biodiversity, and ecosystem services. The 1983 and draft unsigned 2011 agreements bear ample testimony to the reductionist thinking, given that there are attempts to use up the entire water without any consideration of the ecosystem.

The situation has not changed today. The conflict still revolves around the agricultural use of water, particularly for the boro or dry season rice of the region. It is well-known that paddy is the most water-consuming crop with a crop-water requirement of around 1800-2800 mm. Yet, there has been no attempt on the part of government machineries to counsel producers to diversify to other less water-consuming crops over the last 30 years, ever since the talks on Teesta emerged between the two nations. Rather, in India, the minimum support price of paddy has been increased by leaps and bounds vis-à-vis the less water-consuming staples, which in turn also led to a rise in the market price of paddy, thereby incentivising producers to shift more acreage towards paddy, more so during the dry season.

It is now difficult to design a storage project to store monsoon water for dry season use in the TBP given the flat terrain and high sedimentation levels in the Teesta. A major blockade for water recharge in the basin is the highly encroached floodplain which has led to shrinking of the oxbow lakes in the floodplain that were natural storages and rechargers of aquifers, augmenters of lean season flows, and supporters of aquifer-based agriculture. Of course, land acquisition is a politically difficult idea. In any case, it is difficult to believe that groundwater that is already extensively used in the sub-basin for agriculture can actually replace the awesome volume of surface flows, notwithstanding the emerging arsenic problem.

On the other hand, Mamata Banerjee’s proposal of providing water through the Torsa, Raidak, Jaldhaka, and Aatreyi seems questionable from the hydrological, ecological and economic perspectives. These water bodies are only rivulets. Of course, we need better data to come up with more concrete inferences.

While there is the notion that interlinking Manas-Sankosh-Teesta under the national water transfer project can provide the necessary water to Bangladesh this idea may not stand scientific scrutiny considering long-run implications. Firstly, Manas and Sankosh are significant tributaries of the Brahmaputra-Jamuna river system in India and Bangladesh; diverting water from these two rivers will reduce flow in the mainstream of the river, thereby significantly affecting downstream river-bed agriculture, the ecosystem and aquatic biodiversity. Secondly, the Manas-Sankosh link canal may pass through protected areas, creating significant problems for species movement and terrestrial breeding behaviour. Thirdly, the issue of techno-ecological-economic feasibility is not yet clear. Fourthly, the possible reduction in flows through the Jamuna channel in Bangladesh is likely to result in another trans-boundary water dispute, about which Bangladesh has already expressed apprehension.

All the claims and counter-claims are merely hypothetical conjecture in a water governance regime that is marked by lack of analysed data. No government has placed any data in the public domain for independent professionals to research. There is no water accounting, sediment budgeting, or a simple hydrograph of the Teesta in the public forum. So far, governments have exhibited suspicion and apprehension about independent research on rivers crossing international boundaries. There seems to be a tendency on the part of the West Bengal government to shy away from independent scrutiny of the report. Only independent analyses conducted with data will help understand the real problem, and draw up solutions on the basis of institutional mechanisms.

The writer is senior fellow at Observer Research Foundation, Kolkata, and senior economic Adviser at WWF, New Delhi