Reimagining Floods: Reviving Nature-based Solutions for Flood Mitigation

An aerial view of flood affected areas in Bihar on August 28, 2008.

The climatic pattern of South Asia is extremely deceptive. Conditions of drought during the summer months quickly transition into widespread floods in the Ganga-Brahmaputra-Meghna (GBM) basin and along the eastern and western coasts of India. The hope of a plentiful Kharif harvest suddenly turns into a curse, adding to the woes of the farmer already beleaguered by drought during the preceding season. In more contemporary times, floods have the potential to bring life to an absolute standstill in many of the growth centres of the region. This was evident during the continuous downpour and the resultant flooding in Mumbai and Vadodara in the past few weeks. 

Hydro-meteorologically speaking, the occurrence of floods in South Asia is concurrent with the strengthening of monsoon conditions over the subcontinent. Monsoon rains have existed ever since orographic barriers, chiefly the Himalayas, have emerged. The seasonal downpour has contributed to the growth of civilisations. Monsoon rains have weathered rocks and generated sediment which has been transported to and deposited along the middle and lower stretches of rivers such as the Indus, Ganga and Brahmaputra. This sediment in turn has contributed to the creation of thriving agriculture-based economies, the benefits of which are being reaped even to this day. 

Therefore, a more fundamental question that arises at this juncture is – what has led these life-nourishing rains to turn into an uncontrollable deluge that devastates everything on its path? To answer this question, we need to look back at the evolving human-nature interaction in the subcontinent vis-à-vis the monsoons and the changes they bring to the rivers of the subcontinent. 

Ample evidences suggest that humans have co-existed with high flows in rivers since time immemorial. Geographers term this interaction as one shaped by the environment in which the community lives and mutually interacts, a process known as Environmental DeterminismHuman culture has traditionally been deeply intertwined with the natural environment and humans adapted to the changing nature of rivers for harnessing the bounties, while reducing the damages through careful planning and pre-emptive actions.

Living with high flows in the rivers during rainy season was the norm that enabled agriculture to flourish in the floodplains of North India.

The prevalent environmental conditions shaped the behaviour and attitudes of people, enabling them to devise creative solutions that would either benefit the entire community or keep the losses at a minimal level. Colonial reports are a testimony to many such utilisation of traditional wisdom that had been passed from one generation to the next. The Ahar Pyne system of irrigation, utilisation of tanks for storing excess flood water or the ingenious way to divert the nutrient-rich upper flows of the Damodar river and its tributaries into each individual field for cultivating cereals in parts of Gangetic Bengal, are all examples of indigenous practices.

This interaction started changing from the middle of 18th century as settlements started getting bigger, requiring ‘protection’ from the seasonal disruptions in the floodplains. Moreover, colonial imperialism, armed with the European knowledge system which was unaccustomed to the realities of the subcontinent failed to incorporate the indigenous practices of the communities. It superimposed a “control and reclaim” policy that was in-sync with the objective of the time- to generate more revenues for the East India Company through feudal administrative arrangements like the Zamindari system. 

The flood-resistant varieties of staple crops were forgotten for more economically profitable ones that required assured irrigation along with embankments that would prevent the submergence of agricultural fields. Thus, instead of being the harbinger life and prosperity, the Kosi and Damodar became sources of sorrow for their respective regions. A formidable shift had already begun – one that highlighted the response of human societies to the influence of physical environment, often with transformative powers to alter the physical environment to suit their need. This is best explained by the theory of Possibilism, which stands as a contrast to Environmental Determinism. It can be classically expressed in Lucien Febvre’s famous dictum, “There are no necessities, but everywhere possibilities; and man, as master of the possibilities, is the judge of their use”. 

Cross-sectional sketch showing (a) various sections of the floodplain (b) manmade constructions on the floodplains and (c) the role embankments play in raising the riverbed. PC: KS Valdiya. Source: www.researchgate.net.

The use of such possibilities only grew as structural interventions for flood control became the norm of the day, which has continued even after independence. The short-term gains of flood control outweighed the long-term benefits of a thriving riverine ecosystem and the services it provides.

Humanity has only recently started taking note of the fact that structural interventions have only exacerbated the problem rather than solving it. The river’s intrinsic capability to flush sediments along with the functioning of its ecosystem constituting the elements of Water, Energy, Biodiversity and Sediments (WEBS) has been hampered significantly. Due to the accumulation of sediments in embanked stretches, the riverbed has risen well above the surrounding land and cases of embankment breach have been on the rise. It would not be too far-fetched to connect the channel avulsion of the Kosi in 2008 to such anthropogenic interventions that has resulted in immense damage to those settled downstream of the embankment breach.

Moreover, flood damages keep increasing as the river’s space is encroached upon and ‘developed’ for commercial purposes. This has increased the exposure to high flows of the rivers manifold. The normal riverine process of spills due to more than bank-full discharge has acquired a ferocious character that needs to be ‘dealt with’ and ‘tamed’.

The solution to the problem of floods need to shift from an engineering-driven, reductionist approach to a geographically informed strategy that puts rivers’ ecology at the centre of any possible solution for this manmade mayhem. One probable strategy can be to give rivers the space they require by undertaking the zonation of floodplains and imbibing the ‘rights’ of a river in a strong legislative framework. The Australian geographer Griffith Taylor affirmed in 1948 through his theoretical contribution of neo-determinism,” …he(man) should not, if he is wise, depart from directions as indicated by the natural environment. He (man) is like the traffic controller in a large city who alters the rate but not the direction of progress.” Incorporating nature-based solutions is the only way forward and any deviation from it will be a futile exercise, as it will only marginally address the issue.

Sayanangshu Modak

The views and opinions expressed in the article are those of the authors and do not necessarily reflect the official policy or position of The Tilak Chronicle and TTC Media Pvt Ltd.

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