Why Vembanad's houseboats, a pillar of Kerala tourism, have environmentalists worried

Once the humble kettuvallam, a traditional rice barge made of coir and jack wood, the Kerala houseboat has, over the past two decades, transformed into a symbol of tropical luxury. Many now boast air-conditioned suites, jacuzzis, and rooftop lounges. The industry sustains thousands of workers, from boat pilots and cooks to cleaners and repairmen, and fuels an entire shore-based economy of vendors, mechanics, and fishermen. For Alappuzha and Kottayam districts, Vembanad is not just a lake; it is a livelihood.

But beneath this postcard-perfect spectacle runs an undercurrent of concern.

Environmentalists and local residents warn that the boom in houseboat tourism has come at a steep ecological cost. The once-pristine lake — designated a wetland of international importance under the intergovernmental Ramsar treaty on the conservation of wetlands, adopted in 1971— is choking on pollution and unchecked development along its banks.

An April 2025 report submitted to the government by the Centre for Water Resources Development and Management (CWRDM) has flagged growing concerns over the environmental sustainability of Kerala’s Vembanad Lake, particularly in relation to houseboat tourism. The study, which revisited earlier assessments of the lake’s carrying capacity, notes that the maximum number of boats that the lake can safely accommodate has been increased from 315, as determined in a 2013 study, to 461. Even with this revision, the lake is currently hosting far more vessels than it can sustainably support. According to the report, there are 954 boats operating on the lake at present, but only 821 of these are officially authorised to do so.

The report identifies the discharge of waste from houseboats as the primary factor restricting the lake’s carrying capacity. While licensed boats are required to have bio-tanks and sewage treatment arrangements, the sheer volume of vessels and their operational practices have placed immense pressure on the ecosystem, it states. Greywater (wastewater), kitchen waste, and untreated sewage from unlicensed or poorly managed boats contribute to water contamination, affecting aquatic life, fish breeding grounds, and the overall health of the lake, the report adds.

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“The carrying capacity of Vembanad Lake has been exceeded at every level,” agreed Dr. Neehara Girijan, a marine biologist. “The pressure from hundreds of houseboats, motorboats, and other recreational vessels has altered the natural balance of the ecosystem. Continuous boat movement causes turbulence, which accelerates shoreline erosion and disturbs the fragile breeding grounds of fish and other aquatic organisms.”

Dr. Neehara pointed out that the problem extended beyond mere congestion. “Most of these boats discharge greywater, fuel residues, and cleaning agents into the lake, leading to gradual contamination of the water. The constant noise and vibration from engines also affect the feeding and breeding behavior of native fish species and migratory birds,” she explained.

Experts warn that exceeding the lake’s carrying capacity is not just an environmental concern but also a long-term threat to the very tourism industry it supports. Increased boat traffic leads to shoreline erosion, habitat destruction, and higher pollution levels, which in turn could affect the fish population and scenic beauty that draws tourists in the first place.

According to Dr Neehara, Vembanad, which had been once known for its rich biodiversity, is now showing signs of ecological fatigue. “The lake’s self-cleansing capacity is limited. When the carrying capacity is breached, the lake cannot naturally recover from the pollution load. The decline in fish catch, the spread of invasive species, and recurring algal blooms are all warning signs,” she added.

The CWRDM report calls for stricter enforcement of licensing regulations, better monitoring of waste management practices, and potential limits on the number of operational boats. Without urgent intervention, the balance between tourism development and ecological preservation may tip, placing Kerala’s backwaters which are a critical natural and economic resource, under serious strain.

Dr. Neehara too stresses that while the houseboat industry contributes significantly to the local economy, it must be managed more sustainably. “Regulated operations, periodic environmental audits, and stricter waste management practices are crucial if we want to preserve the lake for the future,” she said.

According to multiple studies conducted between 2009 and 2018, houseboats discharged an estimated 23,016 litres of wastewater into Vembanad Lake each day, gradually degrading its ecosystem. The overcrowding of these vessels has had a particularly harmful impact on local fishermen, it was found, with pollution from houseboats contributing to the decline of the lake’s once-abundant fish stocks. Water quality in several parts of the lake has deteriorated significantly, exacerbated by additional pressures from industrial activities. Nearly 260 million litres of trade effluents enter the lake daily from Kerala’s industrial belt, while faecal coliform counts have been recorded as high as 1,800 per 100 ml in some areas, claimed the studies.

Those dependent on the houseboats for their livelihood, however, deny any role played by the vessels in polluting the lake.

“It’s almost impossible for houseboats to slip up these days as the systems are far tighter now,” said Christopher George, a long-time boat worker on the Vembanad backwaters. He recalled that in the early days of the trade, things were not so regulated. “Before the new law (Kerala Inland Vessels Act) came into effect in 2010, and for a few years after, there were real issues with waste from houseboats going into the lake,” he admitted. “Now, every boat is fitted with bio-tanks to collect sewage. Once every three months, we take the boats to an authorised sewage treatment plant where the tanks are emptied and cleaned. The rules are very strict; no one can discharge sewage into the lake anymore,” he insisted.

But when the conversation shifted to kitchen waste, Christopher became cautious. “That’s a different matter,” he said after a pause. “It’s better not to get into that.”

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Most environmentalists stick to their point that kitchen waste from almost all houseboats is being directly discharged into the lake, a claim that boat owners strongly deny.

Meanwhile, the Kerala Maritime Board, responsible for overseeing inland vessels and issuing licenses to the houseboats, holds a differing view from the CWRDM regarding the lake’s carrying capacity. According to a just-concluded survey conducted by the Board, there are between 1,200 and 1,500 vessels currently operating in Kerala’s inland waterbodies. This includes houseboats, ferry boats, and other types of recreational vessels.

“As for the claims about overcrowding or an excess number of boats beyond the lake’s carrying capacity, those are unfounded. In the past twenty-five years, not a single accident has been reported due to a collision between boats, which clearly indicates that congestion is not the problem, said Jofin Lukose, surveyor with the Kerala Maritime Board. “The accidents that have occurred are mostly because of reckless driving or intoxicated guests falling overboard. Some incidents of fire have also been reported, but those were caused by poor-quality electrical wiring that didn’t meet safety standards,” he added.

“The carrying capacity is calculated based on the pollution load. The houseboat industry is 25 years old, and there has never been any large-scale pollution, as some claim. It’s flowing water, after all. We use special tanks for human waste and have treatment plants for it. Boats without these systems are not issued licences. Every boat undergoes a yearly fitness survey and mandatory dry-docking once every 30 months,” insisted houseboat owner Anas Ayoob.

He added: “After the Tanur boat tragedy of 2023 (the vessel capsised, causing 22 deaths), the government strictly limited the number of passengers to 50 per boat and anything beyond that is illegal. There are boats that can technically carry over 200 people, but their licence still caps them at 50.”

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Boat owners often shift the blame onto government authorities, including not just the Maritime Board but also the Kerala State Pollution Control Board. They frequently cite delays and complications in the licensing process as the main reason behind the overcrowding of vessels in Vembanad Lake. “Because the licensing process at the Alappuzha port has been suspended, many houseboats are now being registered at other ports like Kodungallur and Kollam, and then brought back to operate in Alappuzha,” claimed one of the office bearers of the All Kerala Houseboat Owners Association. “According to the Kerala Inland Vessel (KIV) Rules of 2010, vessels are permitted to operate only within the jurisdiction of the port where they are registered. But here, that regulation is being openly violated, taking advantage of the provisions under the Union Government’s Inland Vessels Act, 2021.”

Lukose insisted, however, “as far as our office is concerned, we are strictly enforcing the law”. Regarding concerns raised by boat owners about registration and licensing from other ports, he compared it to not allowing a vehicle to operate outside the district in which it is registered.

Each houseboat in Alappuzha typically employs three to five workers, including the driver, cook, and service staff, meaning that with around a thousand boats in operation, an estimated 3,000 to 4,000 people are directly employed in the sector. Beyond these workers, a much wider economy thrives along the banks of the Vembanad Lake, built entirely around the houseboat tourism industry. From vegetable and meat suppliers to fuel depots, laundry services, welders, carpenters, and boat repair units, an entire ecosystem depends on the continuous movement of these floating hotels. Local farmers, fishermen, and transport operators also benefit from the steady flow of tourists who arrive throughout the year.

Many boats now offer five or six bedrooms with air-conditioned, star-category facilities, modern bathrooms, and restaurant-grade kitchens. Guests are served freshly cooked local dishes, often prepared from produce bought directly from nearby markets.

This has turned houseboats into one of the strongest pillars of Kerala’s tourism economy, generating employment and supporting a vast network of ancillary trades. Despite facing challenges such as high maintenance costs, pollution concerns, and strict licensing norms, the sector continues to sustain thousands of livelihoods while projecting the backwaters as the state’s most iconic tourism symbol.