The Ganges Water
Effects and Implications
M. Monirul Qader Mirza
Water Science and
Political differences and mutual recriminations have long characterised the uneasy Indo-Bangladesh bilateral relationship. Among the primary issues of contention between the two states has been that of water-sharing of the Ganga River. The construction of a barrage by India at Farakka in West Bengal diverted the river water into two distributaries, thereby reducing the water inflow into Bangladesh. While India saw this construction as a sovereign right, Bangladesh held it as a violation of its own rights as a lower riparian country. In 1996, after close to two decades of political deadlock on the issue, the two countries arrived at an agreement on mechanisms of water-sharing that determined the extent of Bangladesh’s right to access the river’s dry season flows. But even though a political agreement has been reached, the barrage and its impacts remain hotly contested in both India and Bangladesh.
The roots of the dispute lie in the barrage’s vastly different consequences on the two sides of the border. India commissioned the barrage in 1975 to make the Calcutta port navigable. By diverting the Ganga into the Hugli-Bhagirathi River, on which Calcutta is located, India hoped that the barrage would regenerate the city’s harbour. However, the project also resulted in the reduction of the river’s dry season flow into Bangladesh, causing a subsequent regional environmental decline. Dhaka claims that the barrage caused an adverse impact on the country’s agriculture, fisheries and navigation. This emerged as the basis of opposition to the project from both Bangladeshi politicians and civil society.
Even while the political debate and acrimony has continued for decades, there has been inadequate scientific work on the barrage’s impact. Monirul Qader Mirza, a scientist and editor of the 2004 The Ganges Water Diversion, is well aware that “much of the techno-political debate over the impact of the Farakka Barrage on Bangladesh is based on observations and anecdotal evidence rather than sound analyses of relevant data”. Mirza’s compilation deals with the environmental effects of the Farakka project, as well as that of other smaller but numerically significant lift transfers along the river; in so doing, he provides a much-needed scientific perspective. The book offers a breath of fresh air on an issue that has been reduced to a largely polemical and politicised debate, tinged with resounding hydro-nationalism.
Facts and flow
Much of the hard data that serves as the background and foundation for the book’s analysis comes in the second chapter, ‘Hydrological Changes in Bangladesh’. Using the flow data of the Ganga at the Hardinge Bridge in Bangladesh, the book’s editor, Mirza, comes to the surprising inference that there has been a 13 percent increase in the river’s peak-discharge after the construction of the barrage. A closer examination of the claim, however, reveals that the author has included the years from 1935-47 in his analysis – a period when the annual peak-flow at Hardinge Bridge was very low, inevitably bringing down the average peak-flow data for the pre-Farakka period. While there could be a multitude of reasons behind these very low pre-1950 figures, they cannot constitute a sound basis to evaluate the 1975 construction at Farakka. On the other hand, Mirza makes a stronger presentation of the impact on dry season flow at the Hardinge Bridge by exploring the average monthly discharge for March-April between 1965 and 1997.
The author also looks at the impact of the barrage on the Gorai River, a tributary of the Ganga downstream from the Hardinge Bridge. In contrast with the earlier conclusion that there has been an increased peak-flow on the Ganga, Mirza suggests that the Gorai’s peak-flow has clearly declined. This incongruence is tentatively explained as a result of the Gorai River “aggrading due to sediment deposition, which results from decreasing inflow from the Ganges into the Gorai River”. Indeed, such important processes need to be examined in a more intensive and extensive manner, as the data could provide an ideal basis for purposes of collaborative research and sharing of detailed hydrological knowledge between the two states.
Impact of diversion
In the following chapter, S K Mazumder, an engineer, explores the possible links between the barrage and the disastrous 1998 floods in the Malda District of West Bengal. The author identifies inoperable spillway gates, the deposition of sediments upstream from the barrage, drainage congestion in the Malda basin, the meandering of the Ganga and the breaching of its embankments as the primary causes of the flood. His prescription of ‘training’ rivers as an essential strategy for river engineering, however, is problematic: “It is of utmost importance to control the river Ganga both upstream and downstream of the barrage to arrest erosion … Considering the national importance of the project, it is desirable that the Central Government … should take the responsibility of training the river upstream and downstream of the Farakka Barrage.” Indeed, such a perception of ‘national’ priorities needs to be reviewed – these have already been used to justify massive investments into projects that attempt to control rivers, often with questionable long-term economic gains and unaccounted-for environmental costs. Rivers are not bound by national boundaries. They need to be understood in a framework that not only involves regional priorities, but is also backed by credible scientific and economic understanding of the vast processes associated with the great Southasian rivers.
Contributors to The Ganges Water Diversion highlight several of the negative consequences of the barrage, including changes in the flow of the Gorai and the growing salinity in southwest Bangladesh. Maminul Haque Sarker, a leading river morphologist, for instance, explores the physical changes in the Ganga-Gorai river system that have necessitated upstream human interventions – a particularly important discussion for the potential it opens up for future research. A large part of the Sunderbans’ fresh water supply is received from the Gorai, which connects upstream interventions to a much wider issue, given the vast number of people that rely on the mangrove ecosystem. The authors point to a “need to increase the discharge of the Ganges River at Hardinge Bridge during the dry months in order to limit salinity in the Southwest region at certain threshold limits.”
M Sinha analyses the impact of the Farakka Barrage on both upstream and downstream fisheries. He notes that the barrage’s construction “has adversely affected the fishery of river Ganga in its upstream, especially of the migrant fish population. But the fisheries downstream, especially of Hugli estuary, have shown a continued upsurge after the commissioning of the barrage.” The downstream movement of salinity in the Hugli-Bhagirathi has been well documented. Sinha, however, does not separate the figures of increased downstream fish landings in a manner that allows the barrage’s impact to be singularly identified, in comparison with the widespread changes that have come about due to the introduction of mechanised fishing practices. The chapter also fails to address the issue of the potential sustainability of the increased fish catch.
Rivers of Southasia
Some of the more indirect implications of water diversion are also addressed in these pages. Within issues of ecosystem change and agriculture, correlations become increasingly general and less quantitative, highlighting the complexity of these linkages and the lack of scientific information on them. Ansarul Karim notes that, “historically the Sundarbans has evolved under the reduced salinity, which used to be maintained by large amounts of freshwater upstream. The decline of forests is directly related to the declining flow of freshwater in the rivers.” A more politically sensitive impact of water transfer has been its effects on agriculture. Mirza and Altaf Hossain seek to demonstrate the adverse effects of the Farakka Barrage on Bangladesh’s agriculture, concluding that “Productivity of crop agriculture has significantly reduced.” While not all of these claims are backed by convincing data, the environmental impacts addressed in these chapters are nonetheless significant.
As SAARC leaders prepare for their Dhaka summit, it is important to emphasise that river engineering cannot be allowed to disconnect Southasia: it is, after all, rivers that tie the region together in the first place. In an era when water has already emerged as a critical resource, Southasian states would do well to build a cooperative framework to deal with the issue and use it as a basis for economic advancement. The time has come to break away from the traditional ways of thinking about water and rivers within narrow, nationalist frames; instead, we need to arrive at a holistic, trans-disciplinary approach. The Ganges Water Diversion lays open gaping holes in these related knowledge bases. Along the way, it establishes the need for extensive, collaborative research on water in Southasia that is based on a new paradigm. Such an approach needs to transcend the limits of national boundaries and refrain from making water a domestic, political tool. While Mirza’s book raises important issues surrounding this question, it is beyond the scope of scholars alone to accept this millennial challenge. Will the SAARC leaders read the rising tide?