- Kuttanad’s ecological crisis is the result of decades of human interventions that have disrupted the region’s natural hydrology, fisheries, flood regulation and wetland ecology.
- Restoring Kuttanad requires a shift from controlling nature to living in harmony with it, including an evidence-based reassessment of major engineering structures and stronger protection of the Vembanad wetland ecosystem.
- It also calls for community-led restoration, from tackling water hyacinth and pollution to implementing long-pending recommendations for sustainable farming and wetland management.
- The views in this commentary are that of the author.
The Kuttanad region of Kerala, often celebrated as the “rice bowl” of the state, is a landscape of profound beauty and immense ecological significance. Yet, its existence is a delicate balancing act, a testament to both the generative power of nature and the often-destructive ambition of human intervention. This intricate wetland system, a mosaic of lush green paddy fields, labyrinthine canals, and the vast expanse of Vembanad lake, is a geographical marvel that is simultaneously a victim of its own fertility and the relentless pressures of modernisation.
Kuttanad is world-renowned for its below-sea-level paddy cultivation and unique brackish-water ecosystem. Alongside this remarkable agricultural practice, the region’s brackish-water ecosystem supports a thriving inland fisheries sector, with the Vembanad estuary serving as a critical nursery for numerous fish and prawn species. Together, these intertwined livelihoods — agriculture and fisheries — form the economic and cultural backbone of Kuttanad. So distinctive and globally significant is this integrated farming system that the Food and Agriculture Organization (FAO) of the United Nations has recognised it as a Globally Important Agricultural Heritage System (GIAHS), placing Kuttanad alongside other iconic agricultural landscapes like the terraced rice fields of the Philippines and the saffron fields of Kashmir.
Geologically speaking, Kuttanad is a young and dynamic landscape. In the distant past, this region formed part of the shallow coastal shelf of the Arabian Sea. Over millennia, the powerful rivers originating in the Western Ghats, chiefly the Pampa, Achankovil, and Manimala, carried massive loads of silt and alluvium from the mountains to the coast. As these rivers met the sea, their currents slowed, forcing the suspended sediment to settle and accumulate. This relentless process of deposition gradually built up the land, forming the present-day delta and giving rise to the unique backwater system that eventually opened onto the Arabian Sea through the Kochi bar mouth. This geomorphological history rendered Kuttanad a region defined by water — a landscape where land and sea are in a constant, negotiated embrace. Today, this territory encompasses approximately 304 sq km of garden lands (elevated areas suitable for coconut and other plantation crops) and a staggering 524 sq km of low-lying rice fields, much of which lies below sea level. The remaining area is a complex network of waterbodies, all intricately connected to the Vembanad estuary, creating one of the most distinctive agrarian ecosystems on the planet. Coastal mangrove forests likely thrived in the low-lying coastal areas of Kuttanad during the Pleistocene glacial epoch (2.58 million to 11,700 years ago), when sea levels receded significantly from the land — a conclusion supported by lignitic remains found in the area and the presence of a distinctive type of black marshy, peaty soil, locally known as Kari (means “black”) soil.
The intricate hydrological system in Kuttanad is governed by a rhythm of seasonal extremes. The southwest monsoon, which typically arrives between June and September, unleashes torrential rainfall upon the Western Ghats, swelling the rivers that drain into Kuttanad. The sheer volume of water discharged into the low-lying region transforms the landscape into an inland sea, making floods a regular, almost anticipated, phenomenon. The floodwaters carry with them fresh nutrients, replenishing the soil and making the region incredibly fertile. However, this natural cycle of inundation is followed by a period of equally dramatic change. As the northeast monsoon recedes and the summer heat intensifies, the freshwater flow from the rivers diminishes. This retreat allows for a powerful tidal incursion of saline water from the Arabian Sea, pushing inland through the Kochi bar mouth. During these pre-monsoon months, the entire wetland ecosystem of Kuttanad would naturally transition from a freshwater state to a predominantly saline or brackish one, creating a dynamic estuarine environment that was historically rich in biodiversity.
This natural equilibrium, however, began to be violently disrupted in the mid-20th century by a series of state policies and private interventions driven by the imperative of food security. The “Grow More Food” campaign, launched in the decades following India’s independence, sought to maximise agricultural output. In Kuttanad, this translated into a large-scale conversion of the shallow, fringing areas of Vembanad lake into rice paddies. Bunds (embankments) were constructed, and water was pumped out to create the famous “polders” or padasekharams — rice fields reclaimed from the lake bed. This ambitious reclamation project, while successful in expanding cultivation, came at a tremendous environmental cost. It is estimated that these interventions reduced the original expanse of Vembanad lake by approximately 65%. The loss of this vast water surface area critically diminished the lake’s capacity to absorb floodwaters, acting as a natural shock absorber. Concurrently, the intensification of plantation agriculture — tea, coffee, and rubber — in the adjacent Western Ghats led to widespread deforestation. The removal of forest cover on the steep slopes accelerated soil erosion, dramatically increasing the load of silt transported by the rivers. This immense sediment load, instead of replenishing the delta in a controlled manner, led to the large-scale silting up of the Vembanad estuary, further reducing its depth and exacerbating the flood risk.
Sediments on the lake bed contain microplastics (particles smaller than 5 mm) at concentrations ranging from 96 to nearly 500 particles per sq m. The water column and lake floor are heavily contaminated with polymers such as low-density polyethylene (LDPE), polypropylene, and nylon — much of which originates from discarded fishing nets, packaging waste, and laundry fibres.
Because the Vembanad estuary supports intensive fishing and sustains thousands of families who depend on clam harvesting, bottom-dwelling organisms like the native black clam frequently ingest these plastics. This bioaccumulation disrupts the local food web and poses potential health risks to humans, particularly if seafood is not properly cleaned and thoroughly cooked. This calls for intensive cleaning up of the Vembanad estuary.
To compound these anthropogenic pressures, the farming community in Kuttanad is now confronted with a triad of severe environmental problems: pollution, floods, and salinity. Agricultural runoff, laden with chemical fertilisers and pesticides, pollutes the waterways, degrading water quality. The natural flood cycle has become a destructive menace due to the reduced capacity of the lake and the clogging of drainage channels. And the spectre of salinity intrusion threatens the very viability of rice cultivation, as the paddy fields are highly sensitive to saltwater.
To mitigate the recurrent floods, a major engineering intervention was undertaken: the construction of the Thottapally Spillway. Built to drain excess flood water directly into the Arabian Sea, it was envisioned as a safety valve to protect the paddy fields from inundation. However, this structure has proven to be a largely ineffective solution. Its performance has been inconsistent, often proving inadequate to handle the sheer magnitude of monsoon fury. This was tragically evident during the catastrophic floods of 2018, which brought Kerala to its knees and exposed the vulnerability of the region’s flood management infrastructure. The spillway, designed for a specific discharge capacity, was overwhelmed, demonstrating that such engineered solutions, when conceived in isolation, are no match for the increasingly extreme weather events driven by climate change.
Further, mining and deep-dredging activities currently taking place near the spillway are altering the depth and flow dynamics of these interconnected water bodies. Instead of alleviating floods, excessive or unscientific mining can disrupt natural water movement, leading to waterlogging rather than drainage. The Thottapally coast is naturally dynamic. Studies and local observations indicate that removing large volumes of sand changes wave energy patterns and sediment transport. As a result, the intensity of sea erosion increases along the adjacent coastlines. Over time, this erosion can wash away shorelines, threatening coastal homes and Kuttanad’s protective coastal boundary.
A second, more significant engineering marvel was the construction of the Thanneermukkom Saltwater Regulator, built in 1974. This massive barrage was constructed across the Vembanad lake in an effort to stop the intrusion of saline water from the sea during the summer months, thereby creating a freshwater environment conducive to a second crop of rice (the kumbha season). The regulator was lauded as a masterstroke of agricultural engineering, designed to hold back the tides and preserve freshwater. But, as with the spillway, its ecological legacy has been profoundly damaging. By effectively dividing the estuary into two distinct hydrological zones, the regulator has caused a catastrophic ecological imbalance. While it successfully kept the saltwater at bay on the southern side, it converted a naturally dynamic brackish-water ecosystem into a predominantly freshwater lake. The northern side, conversely, became a more concentrated saline lagoon.
The consequences of this ecological fragmentation were immediate and devastating. Before the construction of the regulator, the entire backwater system was a thriving nursery for estuarine fish fauna. Species like karimeen (pearl spot), prawns, and various mullets flourished in the brackish water mix. The barrier created by the regulator blocked the migration patterns of these fish and fundamentally altered the chemistry of the water, destroying their breeding grounds. The once-rich estuarine fish population has now virtually vanished from the southern reaches of the lake, dealing a severe blow to the livelihoods of the indigenous fishing communities.
Furthermore, the alteration of the salinity regime has had an unexpected and disastrous side effect: the explosive growth of the invasive water hyacinth (Eichhornia crassipes). Water hyacinth thrives in nutrient-rich, stagnant freshwater conditions — precisely the environment created by the Thanneermukkom regulator. Freed from the natural control of saline water, this noxious weed has proliferated at an alarming rate, now choking nearly all the water bodies in Kuttanad. The dense mats of hyacinth form a thick blanket over the water’s surface, restricting sunlight from penetrating the depths. This light deprivation hinders the growth of native aquatic plants and plankton, leading to oxygen depletion. As the plant decays en masse, it consumes even more dissolved oxygen, creating “dead zones” where aquatic life cannot survive. The weed also provides a breeding ground for mosquitoes and impedes navigation, further compounding the human misery. The Thanneermukkom regulator, initially intended as a solution, has thus become a primary driver of environmental degradation, contributing directly to the flood situation by obstructing the natural flow of water and exacerbating pollution through the decay of hyacinth.
In a twist of fate, the very landscapes that have been degraded by these developmental interventions are now being eyed for a new frontier: mass tourism. The Vembanad lake, with its tranquil backwaters, small islands, and lush fringing vegetation, is being aggressively promoted as a major tourism hub. Houseboats, luxury resorts, and commercial shikaras ply the waters, bringing economic prospects to the region. However, given the fragile and critically stressed nature of these wetlands, uncontrolled tourism threatens to be the final blow. The discharge of untreated sewage from houseboats and resorts, the noise and air pollution from watercraft, and the physical disturbance of the banks accelerate the pollution of the water bodies, further destabilising the weakened ecosystem.
Adding to the challenges posed by its geographic peculiarities, the fast-spreading water hyacinths that have choked and polluted the water bodies in this region pose an environmental threat. An integrated, community-led approach is essential to tackle the immediate crisis of hyacinth infestation. A permanent, dedicated mechanism for the removal of the water weed, with the active participation of local communities, must be implemented. This could involve employing kadapuram (traditional fishing communities) to manually or mechanically harvest the weed. Importantly, this should not be viewed as a waste management problem, but as an economic opportunity. The harvested plant material is rich in organic matter and can be efficiently converted into high-quality manure and compost, offering a sustainable alternative to chemical fertilisers for the region’s farmers. Moreover, with appropriate technology, hyacinth can be processed into marketable handcrafted products such as paper, fibreboard, and bio-gas. By incentivising the collection and commercial processing of water hyacinth, the state can transform an ecological menace into a source of local employment and economic value, all while cleaning up the waterways. Such a programme would increase environmental awareness and create an economically viable and sustainable recycling programme that would benefit the local community.
The only time the state government gave serious thought to Kuttanad’s restoration was when it approached renowned agricultural scientist M.S. Swaminathan who himself was born into a family from Mankombu in Kuttanad. In 2007, the M.S. Swaminathan Research Foundation submitted a report titled Measures to Mitigate Agrarian Distress in Alappuzha and Kuttanad Wetland Ecosystem.
The report urged the government to declare fragile wetland systems like Kuttanad as a Special Agricultural Zone (SAZ) to protect prime farmlands. It emphasised halting the reclamation of backwaters and canals, restoring water-spread areas, and clearly demarcating the boundaries of Vembanad lake. The plan also recommended modernising the Thottapally spillway and the Thanneermukkom barrage, as well as constructing main roads on pillars to allow monsoon waters to flow freely and reduce flooding. Additionally, it encouraged the use of short-duration paddy varieties and the adoption of integrated farming systems, such as rice-fish cultivation.
These recommendations formed the basis of the ₹1,840-crore Kuttanad Package, which received Union Cabinet approval in 2008. However, due to poor coordination among implementing agencies, the package has largely remained unimplemented.
Given this litany of interconnected crises, the fundamental question is not how to make minor tweaks to the existing system, but how to arrest and reverse the rapid ecological deterioration of Kuttanad. The path forward demands a paradigm shift — from a mindset of controlling nature to one of living in harmony with it. A serious, evidence-based reconsideration of the effectiveness of the two major engineered constructions at Thottapally and Thanneermukkom is urgently required. Their continued operation is perpetuating a cycle of ecological damage. The possibility of decommissioning these structures permanently should be a primary topic of discussion. While the immediate consequences would require careful management, allowing the natural tidal and fluvial regimes to re-establish would restore the brackish nature of the estuary, thereby controlling hyacinth growth and reviving the estuarine fish stocks. This would also improve the water quality and reduce the heavy sediment load, potentially re-naturalising the flood cycles.
The coastal areas like Kuttanad with a high-density population that depend on coastal resources for their living are also disproportionately vulnerable to the impacts of climate change. Kuttanad, a geographically unique coastal region located about two metres below sea level in Kerala, calls for immediate attention.
Kuttanad and the Vembanad estuarine system stand at a precipice. Its story is a poignant parable of human ambition clashing with ecological limits. The agricultural bounty that once defined this region was achieved through heroic feats of engineering that ultimately sowed the seeds of its current distress. The solutions to its problems lie not in more concrete walls and regulators, but in a holistic approach that acknowledges the interconnectedness of its hills, rivers, backwaters, and sea. It is a call for a new era of environmental stewardship, where the health of the fragile ecosystem is placed at the heart of all developmental decisions. Only by dismantling the barriers that separate human from nature, both literally and metaphorically, can Kuttanad hope to regain its resilience and secure a sustainable future for the generations to come.
Banner image: Fishers at work in Vembanad lake, Kerala, while invasive water hyacinth plants float on the surface of water in the backdrop. Image courtesy of India Water Portal via Flickr (CC BY-NC-SA 2.0).
The author is an adjunct professor at the National Institute of Advanced Studies, Bengaluru.