Kazhuveli wetland

Why is in news? Between a dam and a wetland

In 2021, the Public Works Department (PWD) built a check dam on the Kazhuveli wetland, located in Vanur and Marakkanam taluks of Villupuram district, hoping to convert it into a freshwater lake.

While it sounds like a good plan, it could spell disaster for the bird sanctuary and its associated biodiversity.

Kazhuveli or Kaliveli meaning ‘Passage to Backwaters’ is a brackish water wetland, which feeds into the Bay of Bengal through the narrow 8-km-long Uppukalli creek and the Yedayanthittu estuary.

Over 160 irrigation ponds drain into the sea through Kazhuveli, which is about 10.5 km in width, 28.5 km in length, and spread over 73.01 sq. km.

Listed as one of Tamil Nadu’s 141 prioritised wetlands, Kazhuveli is also a wetland of international significance and a potential Ramsar site, says the Ministry of Environment, Forest and Climate Change’s ‘Wetlands of India’ portal.

The wetland is home to over 200 species of birds and is recognised as an important stopover and breeding ground for about 40,000 migratory birds.

With the annual migratory season about to start in a few weeks, thousands of waterbirds and shorebirds, including several long-distance migratory birds in the Central Asian Flyway, will use it as a wintering ground.

The birds found in the Kazhuveli bird sanctuary include spot-billed pelicans, darters, cormorants, herons, egrets, storks, black ibis, spoonbill, flamingo, spot-billed duck, garganey, common pochard, sandpiper, coots, shanks, and terns.

Many of them have been categorised as ‘vulnerable’ or ‘near threatened’ by the International Union for Conservation of Nature (IUCN).

According to a 2016 report, ‘Important Bird and Biodiversity Areas in India-Tamil Nadu’, by the Bombay Natural History Society and Indian Bird Conservation Network, the area regularly holds over 30,000 ducks in winter, 20,000-40,000 shorebirds, and 20,000-50,000 terns during the migration period