Vembanad Lake - Preserving a Lifeline

How we treat the diverse Vembanad backwater estuarine ecosystem needs careful thought and action.


The Vembanad Lake - local fishermen

The history of kerala is indisputably and powerfully linked to the brave expeditions of the great Portugese adventurer, trader, warrior and diplomat – Vasco da Gama.
This naval commander is said to have discovered a navigable sea route to the Malabar coast in 1498. Vasco da Gamma knew this land as described by the legendary explorer Marco Polo – as the land of black gold (pepper) and other exotic spices and one of the richest places in the world that he had ever seen.

Kozhikode, Crangannoor (Kodungalloor), Kochi, Alappuzha and Kollam were the main trading ports of that glorious era. Soon the Europeans (France, Portugal, Britain and Dutch) would fight naval battles to secure a monopoly over the lucrative spice trade. These wars changed the history of India and in particular Kerala.

Known as the ‘Venice of the East’ – Kerala and its waterways played a major role in this spice trade. These interlinked water bodies stretched over 900 sq km. including inlets from the sea, estuaries of 41 rivers, lakes and natural canals connecting coastal villages and townships. The Vembanad and Ashtamudi lakes together form the backwaters of Kerala. These lakes act as a buffer between the sea and rivers and control floods and tides and most importantly – provide a livelihood for thousands of village folk.

A large transport vessel carrying sacks of grain. These vessels are the predecessors of the current houseboats plying the backwaters of kerala

The Vembanad wetland system is the largest estuarine system in Kerala characterized by a continuous chain of lagoons and backwaters. This wetland system encompasses four districts, Pathanamthitta, Alappuzha, Kottayam and Ernakulam – an area of 219.51 sq. km. The most important part of this wetland ecosystem is the Vembanad Lake. The lake is 96.5 km long beginning in Alappuzha in the south and ending in Azheekkod in the North – covering an area of 132 sq. km. Six major rivers of Kerala namely – Periyar, Muvatupuzha, Meenachil, Manimala, Pampa and Achankoil drain directly into the Vembanad lake. The lake, the surrounding paddy fields, marshes, islands, canals and rivers all together form the vembanad wetland ecosystem. The mighty Vembanad lake drains into the Arabian sea at Cochin forming one of the world’s largest natural harbours.

The Thaneermukkam salt water barrage divides the vembanad wetland system into two zones; the Kuttanad region in the south and the Cochin backwaters in the north. The salt water barrage controls the flow of salt water into the Kuttanad region (also known as the ‘Rice Bowl of India’). The northern part of the lake remains a largely saline wetland ecosystem throughout the year.

Thanneermukkom bund divides kuttanad backwaters from kochi backwaters


The vembanad wetland ecosystem is characterized by its humid tropical weather and as such is considered a tropical wetland that possesses all the characteristic flora and fauna – mangroves, diverse tropical fish, water birds and other avifauna, agriculture etc. For its unique attributes the Vembanad wetland system together with the adjoining Kol wetland system was declared as Ramsar Site in November 2002 (The convention on wetlands, signed in Ramsar, Iran in 1971 for the protection of the wetlands all over the world.)

Kuttanad which is an important part of this ecosystem lies over 500 square kilometers of land and is located 0.6 m to 2.2 meters below sea level – the region with the lowest altitude in India. Kuttanad is a land of paddy (rice) fields – cultivated below sea level. Much of this land was reclaimed from the Vembanad lake in the early 19th century. There is more than 145000 hectors of this wetland under rice cultivation. Almost 60 percent of the total rice production of the state is from this man made wonder; of which is said – ‘God created man; man created Kuttanadu’.

Sand being transported in kuttanad in small country style canoe

The Vembanad wetland is well known for the diversity of fishes, aquatic mammals, mollusca and avian fauna. The floristic diversity of this area is also very rich consisting of hydrophytes, mangroves and mangrove associates. The Kumarakom Bird Sanctuary, spread over 10 acres is situated on the banks of Vembanad lake. The birds roost and nest in the mangroves and inside the dense growth of reeds and grass. There is a virgin, uninhabited island in the middle of the southern region of the Vembanad lake called ‘Pathiramanal’ which is known for its unique biodiversity and specifically for breeding of Black Clam – Villoritta cyprinoids.

Sadly however, this pristine backwater ecosystem is now under serious threat. The five major rivers that drain into the Vembanad lake carry untreated sewage water from the villages and towns situated on their banks. This includes poisonous effluent from the many factories located nearby. The slew of modern and inorganic agricultural practices also endangers the ecosystem. Large quantities of chemicals, fertilizers, pesticides and herbicides eventually seep into the ecosystem threatening and poisoning fish stock, bird life and vegetation. Land reclamation, unrestricted and irresponsible tourism activity is the Vembanad ecosystem’s most significant threat.

Workers collecting shells from vembanad backwaters

More than a thousand commercial houseboats ply the lake. Their lack of concern about adopting green practices is further backed by the ignorance of the local people who enjoy the material wealth generated by tourism and are unencumbered by the long term effects it may have. They do not consider the fact that the very source of their livelihood is dying before their eyes. All manner of waste generated in these boats including plastic, sewage, engine oil etc, is discharged in to the lake, thereby threatening an already fragile ecosystem. Rampant exploitation of the wetland ecosystem continues. Clay mining, shell mining etc. coupled with unscientific fishing methods are other threats that go unchecked.

Large transport vessels of yesteryears have been modified into luxury houseboats which attract a large number of tourists every year. However with the number of houseboats operating in the alappuzha backwaters have multiplied over the years and presently plays a major role in polluting the backwaters.

The most important aspect of the Vembanad lake is its rich floral and faunal diversity, which provides livelihood to millions of people directly and indirectly. In addition, there are the aesthetic attributes of the region that is blatantly abused. The conservation of this unique ecosystem is necessary for future generations and for their very existence. This unfortunately is not being given the seriousness it should be.

Conversing the lake should be a joint effort, and a first step would be to create awareness of the dangers of indiscriminate commercialization.


Article by : P. Manoj (Senior Naturalist - Marari Beach Resort, Mararikulam - Alappuzha)