Forty years ago, an engineer-ecologist in-themaking started a serendipitous journey mandated by his government to enquire into the possible uses of city wastewater. He had just completed his Ph.D from the University of Calcutta, to become the first civil engineer to choose ecology as the subject of his doctoral degree. Without a clue about what to do to find the answer that his superiors wanted, he did what was usual to do in those days. He used his common sense. Dr Dhrubajyoti Ghosh started walking along the outfall canals of the city to check where the city’s sewage was going. Lo and behold, he stumbled across the largest contiguous set of ponds functioning as the sewage treatment plant of the city of Calcutta; an engineered landscape that both treated sewage and kept treatment costs at zero for the Calcutta Municipal Corporation. This unique ecosystem he named the East Calcutta Wetlands. It was to become his muse till the end of his time.

Dhrubajyoti Ghosh worked tirelessly for its preservation, innovated as best as he could and, when he passed away in 2018, he was the only environmental thinker in this city who had twice been honoured by the United Nations for his efforts to name, map and take to the world the sustainability chronicle of these wetlands. His single-minded pursuit, with support from unexpected allies, got East Calcutta Wetlands the Ramsar recognition on 19 August 2002, as a Wetland of International Importance, that the government would have to be committed to protecting. As we complete two decades of that recognition, it is germane to ask what lessons we have learnt for ourselves and for posterity. Though the Ramsar Convention began as an international covenant to protect waterfowls and their habitat, it soon evolved to making ‘wise use’ the cornerstone of its deliberations and this formed the core of its understanding of conservation.

Today, Ramsar’s definition of wise use stands thus: “Wise use of wetlands is the maintenance of their ecological character, achieved through the implementation of ecosystem approaches, within the context of sustainable development.” It was this wise-use criterion that led to the identification of the East Calcutta Wetlands as a Ramsar site. In 1985, after completing the mapping of the wetlands, Dhrubajyoti Ghosh visited Lima, Peru as a World Bank consultant and was asked by experts to visit their respective countries to deliver lectures on this wetland. He proudly invited them to Calcutta if they wanted to understand ‘uniqueness’. Hundreds of international scholars visited the wetlands for more than two decades. In the bargain, Ghosh earned endless brickbats on his home turf. Ironically, as these wetlands gained international recognition, they hit the impregnable wall of apathy of the very city whose citizens of yore had engineered a masterful transformation of a saline ecosystem endangered by the death of the once-flourishing river Bidyadhari. Integrated sewage and solid waste management were central to this innovative effort.

Engineering interventions led to the successful emergence of an upscaled sewage-fed ecosystem whose foundations were laid by Bengali entrepreneur Bhabanath Sen as early as 1880. The Dhapa Square Mile in the outskirts of Calcutta, where Sen began his garbage farming and fish growing initiative, formed the template of an expanded ecosystem after he lived no more. Dhapa was the place from where vegetables and fish produced at a low cost were supplied to the city, saving food miles in the process. Besides sewage being available at no cost and serving as a nutrient for production, organic material, plentifully recovered from the solid waste collected from the city, was used as manure for vegetable production. All this was discovered in the course of an immersive learning process. Little wonder then, that Ghosh named Calcutta ‘an ecologically subsidised city’. Long before sophisticated foreign scholars had begun to talk about smart cities and urban circularity, Calcutta’s frugal innovators had woven sustainability into city survival in their own backyard by utilising its waste. Today, we have forgotten these lessons, banking on our culturally inherited pride in the built environment and dumping our living heritage.

Ghosh’s task was simple: he re-discovered this living heritage as he, with his uncanny wisdom, discarded the typical Bengali bhadralok’s ‘cognitive apartheid’ and upheld the true value of these wetlands. The local community learnt to preserve this integrated waste management ecosystem for purposes of their own survival. They developed knowledge of the lay of the land and the plentifully built engineering structures such as lock gates and siphons, to facilitate the spread of sewage as widely as possible. This led to the nurturing of a stable urban fringe, whose inhabitants do not demand regular employment from the core city. Sadly, the fault lines of misperception, especially by the learned, are jeopardising the survival of this tutorial ecosystem. When the Central Wetland Rules came into existence in 2010, they forbade the entry of sewage into any wetland.

This led to a long innings of official correspondence between the state government and the Centre regarding East Calcutta Wetlands. When the amended rules rationalised this in 2017, much misunderstanding still remained and the Dhapa dumpsite was frowned upon. Opinion was expressed that this dumpsite should go outside the ambit of the Ramsar site, without once attempting to understand the integrated nature of resource recovery from waste in this total ecosystem. Today, the cost saving of these wetlands for the city administration is given no importance, much less it is attempted to improve their health by generating real-time data and monitoring.

As usual, the wetlands face urbanisation pressure that is chipping away at their vitality. Legal provisions were put in place to ensure the continuity of this ecosystem by dedicating an entire Act for its governance. But in the face of political and external interference, the East Kolkata Wetlands (Conservation and Management) Act 2006 has proved quite ineffective. Evolving a sustainable and climate-friendly governance model demands that the productivity of this ecosystem be ramped up on all counts and by all available pathways. Engaging innovative capabilities of the wetland community and experts, together with institutional and informal financing initiatives, are the key to the survival of this ecological marvel. After all, we should not be proselytising sustainability while actually facilitating destruction.