Hundreds of fisherfolk and residents staged a protest in the banks of the Kosasthalaiyar river in Chennai on Wednesday.

They formed a human chain holding placards that read “This is river, not land,” and demanded that the government withdraw a “fraudulent Coastal Regulation Zone map” that denies the existence of Ennore Creek, which is the city’s largest estuary. The creek is a swampy backwater in North Chennai that sprawls over 13 km between the Pulicat lake in the north and the Kosasthalaiyar river in the south.

Kosasthalaiyar is four times larger than the Adyar and the Cooum, and has faced heavy encroachments. The Ennore Creek is lined with acres of fly ash instead of mangroves. Around 1,000 acres of wetlands have been lost to thermal power plants and ports in the vicinity.

The protesters alleged that the government’s effort to convert 6,500 acres of the Ennore wetlands into industrial estate is India’s “biggest water scam”, and that the human chain was an effort to “fight against corruption in high places and lack of accountability in the government”.

Activists have claimed that the Tamil Nadu government hid a key coastal plan so as to approve illegal constructions along the Ennore Creek. A comparison of maps from the Coastal Zone Management Plan, 1996 – which demarcates the areas along the coast that can be opened up for construction – showed that 1,090 acres of the 8,000 acres of protected wetland along the Ennore Creek have been encroached upon by state and central Public Sector Units.

“The Neer Satyagraham [Water protest] is the first of our direct actions to hold the government accountable,” D Selvaraj, a fisherman and leader from Kattukuppam, said. “We will escalate our protests if the Government refuses to uphold the law and protect our water bodies.”

The agitating fisherfolk are demanding that authorities should use the 1996 plan to appraise future proposals, and remove existing encroachments from there.