Why Governments Need to Rethink Development and Its Costs
Expert Warns of Ecological and Livelihood Impact of Tamil Nadu’s Kazhuveli Check Dam
By Subasree*
June 30, 2025
A regular day at the Marakkanam salt pans in Villupuram district, with workers engaged in their daily tasks/ Photo by SRIRAM R.
Nations and communities have long grappled with a difficult question: should nature be damaged to build roads, cities and industries, or does real development mean protecting the natural systems we rely on to live? In the case of the Kazhuveli wetlands, authorities in Tamil Nadu chose the former. But a wetland researcher argues that sometimes, preserving – or even reversing –development, what she calls “de-development,” may better serve both people and the environment.
Wetlands are areas where water covers the soil or remains near the surface, creating habitats for species adapted to moist conditions. Kazhuveli spans 51.5 km² – roughly the size of Chandigarh’s core city area or the city of Panaji in Goa.
Located along the Coromandel Coast, Kazhuveli supports 229 bird species, 84 fish species, and vulnerable animals like the Indian Pangolin and Indian Flap-shelled Turtle. It serves as a vital feeding, resting and breeding ground for migratory birds along the Central Asian Flyway, including ducks, herons, storks, waders and the Spot-billed pelican. It is also one of southern India’s most important heron habitats.
Kazhuveli is the second-largest brackish water lake in south India and holds the status of a Ramsar site under the 1971 Ramsar Convention, recognised globally for its role in conservation and sustainable use.
Around 65,000 people, mostly from marginalised communities, live in and around the sanctuary and depend on the wetland’s health for their survival.
In 2021, Tamil Nadu’s Public Works Department started building a check dam across the wetland to slow water flow, aiming to create a freshwater reservoir to recharge groundwater, support agriculture and supply drinking water to Chennai. By December the same year, the Forest Department declared Kazhuveli a bird sanctuary, and issued a halt notice upon finding the site fell within the eco‑sensitive zone of the newly declared Kazhuveli bird sanctuary. The construction of the dam later resumed and was completed in 2023. As of June 2025, the dam is fully functional.
In March 2023, the state also approved a silica mining project within the eco-sensitive zone near Kazhuveli. In March 2024, the state government leased 3.73 hectares of land to Tamil Nadu Minerals Limited (TAMIN), valid for 10 years. As of June 2025, the project appears to remain in the approval stage.
Kazhuveli wetlands, rich in biodiversity, come alive with the vibrant flocking of migratory birds during the November season / Photo by SRIRAM R.
To understand the deeper implications of the proposed changes, Newsreel Asia spoke with Meghaa Sathish, a wetland researcher with a background in environmental science who has worked extensively on coastal wetland conservation in Tamil Nadu. She sheds light not only on what the check dam means for Kazhuveli, but also on how similar decisions are affecting wetlands across the country.
Here are excerpts from the interview:
What is the environmental and human significance of Kazhuveli, particularly as a wetland ecosystem?
Kazhuveli is not only a crucial ecological site but also a vital human livelihood zone. As a shallow wetland surrounded by grasslands, it hosts numerous freshwater lakes that naturally aid in groundwater recharge. The landscape’s watershed features are defined by elevation, determining how and where water enters and exits the wetland and this dynamic makes Kazhuveli highly adaptable to seasonal shifts.
Ecologically, it supports a range of biodiversity starting from birds that serve as critical indicators of ecological health and some species that are exclusively dependent on brackish water environments feeding on wetland creatures like crabs, snails and fish. Wetlands such as Kazhuveli often oscillate between dry desert-like conditions in summer and flood-like conditions during the monsoon—demonstrating their ecological richness and resilience.
Considering the human significance which is equally important in this region, fishing communities from Marakkanam, including prawn gleaners, rely on these ecosystems for sustenance and life. The region also supports tree species like ‘naatu karuvelam’ a thorn variety similar to Prosopis Julifera, found only in such low-lying areas which is important for those who collect these and sell as a part of their livelihood. The ecosystem braces three distinct fishing livelihoods—marine fishers, estuarine fishers and freshwater fishers.
What was the primary rationale or perceived need for constructing the check dam at Kazhuveli?
The check dam was introduced under the broader goal of groundwater recharge, especially considering freshwater scarcity as a planetary boundary— a framework that describes essential environmental thresholds. During dry periods, the region clearly demonstrated a need for water conservation infrastructure, prompting governmental action and the dam was positioned as a solution to meet urban water demands.
However, this rationale overlooked long-term ecological needs, particularly the importance of maintaining freshwater inflow to support mangroves and wetland resilience. There are claims that the dam is not entirely closed and water is sometimes released downstream, but concerns remain over sediment buildup, which alters the waterbed and impacts species migration. Moreover, the construction displaced indigenous communities, who live along the riverbed and made their livelihood from the catches from this wetland.
In 2023, a check dam was constructed along the coastal wetland—now standing tall, it poses a potential threat to the region’s rich biodiversity / Photo by SUBASREE
How has the construction of this check dam specifically impacted the Kazhuveli wetland ecosystem?
The presence of the dam has led to the accumulation of stagnant freshwater – disrupting the natural saline-freshwater balance vital to the wetland. Kazhuveli is a centuries-old ecosystem that evolved with tidal cycles. By blocking tidal flows and freshwater-seawater interaction, the dam interferes with these natural cycles.
This affects species whose life cycles depend on aquatic conditions. For example, dragonflies spend half their lives underwater. Any shift in water quality, flow or salinity impacts such species dramatically which further affects the food chain along the larger side. Altering the ecosystem’s functioning creates dependencies that can’t be sustained naturally, requiring constant human intervention and support, ultimately damaging the resilience of the ecosystem.
Small-scale development projects, while intended for public welfare, can sometimes lead to unforeseen long-term environmental consequences. Do you believe this is the case with the Kazhuveli check dam?
Absolutely. Dams inherently disrupt downstream hydrology. In Kazhuveli, the dam has led to silt accumulation (gradual build-up of fine soil and sand particles in water bodies, which can block natural water flow and affect the health of ecosystems), causing side erosion and damaging mudflats where mangroves thrive. Mangroves are critical for both biodiversity and coastal protection, and their degradation compromises the entire wetland.
The issue extends beyond the dam. A few years ago, a proposed port development project near Kazhuveli was halted only after environmental groups intervened, and the NGT (National Green Tribunal) had to step in. The project, however, had gained momentum due to lucrative contracts. This pattern reflects a national trend—development is prioritized at the cost of ecological destruction. India’s land-use policy seldom includes robust environmental safeguards, revealing a serious gap that must be addressed.
Beyond the intended benefits, how have local salt workers and fishing communities already been affected by the changes to the Kazhuveli ecosystem, particularly regarding their livelihoods?
Local communities, especially the Irulars, are deeply affected. Their livelihoods depend entirely on the wetland’s natural productivity. Government plans to “compensate” for biodiversity loss often involve artificial planting, such as introducing just two fast-growing mangrove species, ignoring the 12 native varieties that sustain the ecosystem of Kazhuveli.
This kind of one-size-fits-all rehabilitation does little for fish populations or the ecological balance necessary for these communities to survive. Salt pan workers also suffer, as the altered water flow and salinity disrupt the concentration levels required for effective salt production and this impact would show out large consequences in the future.
Photo by SRIRAM R.
When the natural flow of rainwater or seawater is altered, what specific impacts does this have on the animals, fish and birds that depend on these aquatic environments?
Disrupting natural water flow fundamentally breaks down brackish water ecosystems. These ecosystems are delicate, and many species depend on the ebb and flow of tides. For example, tidal receding and inflow patterns determine where and when aquatic species breed and feed.
Cutting off these flows leads to habitat loss for marine organisms, and birds lose their feeding grounds. The whole food chain is disturbed. As a result, species vanish from these areas, and the web of life they support collapses.
Given Kazhuveli's coastal proximity, how do changes in its water flow and salinity affect the adjacent sea and marine life?
The answer to this question is basic environmental science to consider before any developmental project which is often overlooked by policymakers, leading to large-scale ecological collapse over time.
Without the dynamic of brackish water, breeding grounds for numerous species are lost. These patterns—where fresh and saltwater meet—are critical breeding zones for species of both the environment. And any disruption in this ecosystem affects marine life even beyond the wetland, impacting the adjacent sea.
Have you observed similar instances in other parts of India where development activities have caused significant damage to vital wetlands, forests, or rivers?
Yes, and even within Tamil Nadu. Kattupalli’s biodiversity hotspot faced threats from proposed Adani port plans. In Chennai, the Pallikaranai marsh suffered due to silent development encroachments. The Kelambakkam desalination plant is another unnecessary venture that could disturb local ecology and there are many more to quote.
Another key example is from Dehradun, where a dam project, similar to the Kazhuveli case, displaced marginalized communities and led to massive sand mining along the Yamuna riverbanks, disturbing the local ecosystem and livelihoods.
A powerful parallel can be drawn from Chilika Lake in Odisha as well. As India’s most dynamic shallow lagoon ecosystems, stretching for about 65 km in length, the lake faced a decline in the sediment load due to the construction of a dam in its catchment area. This has contributed to severe erosion along the Chilika’s shoreline which in turn resulted in reduced sediment supply worsening the situation. And the species diversity significantly went down as it directly impacted on the lives of fishermen in the region affecting their livelihoods. This case highlights how fragile wetland systems can be and the importance of balancing development with ecological resilience.
These examples, including Kazhuveli, show a recurring pattern—development projects that disregard environmental systems often end up disrupting delicate ecologies and marginalizing vulnerable communities.
What potential long-term environmental, social, and economic problems could arise if we continue to modify natural spaces like wetlands without adequate environmental consideration?
Alienating local communities from their ancestral land is one significant social problem which impacts the economy of these families. Sand mining and unchecked development already harm people’s livelihoods along with showing degradation in the environmental space. We are failing to place value on nature and its services, treating ecosystems as liabilities rather than assets.
“Penalties” as compensation for environmental damage often acts as a token to minimize the outcast of the result produced by such development activities. And this leads to normalizing natural degradation instead of prioritizing proactive conservation. This system should be checked properly and ecological services should be respected as vital to sustainable living.
Reflecting on the Kazhuveli case, what alternative approaches could have been considered to better balance both development goals and environmental protection from the outset?
Long-term impact assessments should have been conducted before development. Instead of building new infrastructure, the government could have focused on improving existing structures. Projects that harm vulnerable communities must be reconsidered or abandoned.
Sometimes, de-development is the real development. The removal of aquaculture farms at Kazhuveli is a powerful example—it restored natural water flow and contributed more effectively to groundwater recharge than artificial solutions. Thus, de-development as an alternative measure would help restore the natural ecology of the environment.
Now that the check dam is constructed, what proactive steps should the government consider taking to mitigate its current impacts and prevent further environmental degradation in the future?
Damage has already occurred, but there are still steps that can be taken. The Gate at the downstream of the dam must be regulated effectively to manage water flow. Further construction of similar structures should be halted in the future considering the ill-effects that it can bring about.
Further, Silts must be allowed to move freely. The desiltation methods (removing accumulated silt or sediment from water bodies to restore natural flow and depth) that are practiced already are ineffective and a natural, unblocked flow of water must be restored if the wetland has to recover to its past environment.
In balancing human development benefits against dangers to biodiversity and ecology, what principles or frameworks should guide decision-making, and to what extent should one take precedence over the other?
A multi-disciplinary expert panel should be formed to conduct detailed surveys and assessments before proceeding with any development projects as such. Proper boundary delineation can help prevent encroachments along areas of ecological significance and every step in the process must be guided through scientific planning.
Most importantly, wetlands must be treated as ecological assets, not just as land to be exploited in the name of development. The government should start with a baseline of ecological literacy at the committee level where policy formulation must root from analysis and decision making. Only then can development and conservation be truly balanced without disrupting the natural ecology that holds the legacy across years to come.
(*Subasree is an independent journalist based in Chennai. She writes on environment, policy, human struggles, empowerment and social justice.)
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