CHENNAI: As Chennai stares at an uncertain water future amid rapid urban expansion and climate volatility, the Tamil Nadu government has approved plans to build the city’s sixth reservoir at Tiruporur, on the southern fringes of the Chennai Metropolitan Area (CMA).
While the Water Resources Department (WRD) projects the reservoir as a crucial intervention to meet the city’s growing demand, fishermen and environmentalists warn that the project could irreversibly alter a sensitive coastal ecosystem that has sustained livelihoods for generations.
The reservoir will be constructed at a cost of Rs 471 crore, covering an area of 4,375 acres. Designed with a depth of 3 metres, it will store 1.655 TMC of water and act as both a drinking water source and a flood buffer.
According to the proposal, the reservoir will serve 12 revenue villages such as Nemmeli, Krishnankaranai, Pattipulam, Saluvankuppam, Paiyanur, Thandalam, Kalavakkam, Tiruporur, Tiruvidanthai, Punjeri, Kadambadi, and Mamallapuram along with extended CMA areas. Officials also claim the project will recharge groundwater, reduce inundation through peripheral flood carrier drains, and improve natural drainage patterns.
During a recent visit to the proposed site and surrounding fishing villages, DT Next found a deep divide between official assurances and local fears that pits urban water security against coastal ecology and traditional livelihoods.
A backwater that breathes life
The proposed reservoir site falls within a portion of the Kazhuveli region, commonly referred to by locals as ‘uppam kali’ salt pans that form part of the city’s coastal ecology along the Bay of Bengal.
Scientifically identified as a backwater, the area functions as a dynamic wetland system influenced by seasonal rainfall, tidal ingress, and evaporation.
When this reporter visited the site, the shallow waters, often only hip-high to an adult, resembled a miniature Bay of Bengal. Group of birds skimmed the surface in search of food, while fishermen walked through the water carrying nets. According to local accounts and preliminary ecological data, over 102 bird species use the area as a feeding and hatching ground.
The wetland also serves as a nursery and breeding ground for shrimps, including valasu iraal (giant freshwater prawn or giant river prawn), tiger shrimp, and sennaku iraal species critical to the local economy.
Narayanan, a fisherman in his late 50s, stood by the shallow waters with a shrimp net slung over his shoulder – a routine he says has remained unchanged since childhood. “Since I was 12, I’ve been carrying my shrimp net and walking nearly 15 km to fish here,” he averred. “My father, my grandfather, and all my ancestors used to fish in this lake. We use different kinds of nets – kondai valai, mani valai, pannu valai, etc. Now the government says they will convert this salt pan into a freshwater reservoir. This will destroy this ecosystem and our livelihood.”
For fishermen, the salt pans are not wastelands but living landscapes, shaped by centuries of coexistence between humans and nature.
Lessons from desalination
In Kovalam Kuppam, a densely populated fishing settlement nearby, residents point to the Nemmeli Desalination Plant as a cautionary tale. Saravanan, a local fisherman wearing a DMK t-shirt, told DT Next that political changes have done little to address their concerns.
“Whether it is ADMK or DMK rule, fishermen suffer,” he lamented. “After the desal plant started functioning, salinity levels increased. Fish stopped coming to this side. We’re no longer able to do karai valai (shore-based fishing). If another major project comes, what will happen to us?”
Chennai currently requires 1,100 million litres per day (MLD) of water. According to WRD projections, this demand is expected to double in the next 10 years, with estimates indicating that the Greater Chennai Corporation alone may need 2,178 MLD by 2035.
The city’s expansion along the ECR and OMR corridors, driven by IT parks, residential projects, and tourism hubs, has placed enormous pressure on existing water sources. Officials argued that without new storage infrastructure, Chennai risks repeating the water crises witnessed in recent years.
WRD dismisses concerns
The project has drawn attention from political representatives as well. SS Balaji, Tiruporur MLA (VCK) urged caution and transparency. “A fresh, transparent, and procedurally compliant tender should be issued only after obtaining NGT. All statutory environmental clearances must be done after completing hydrological, salinity, and feasibility studies issuing the relevant GO, and also give details about financial sanction,” he explained.
He also stressed the need for public consultation before moving forward.
However, WRD dismissed concerns that the project would damage farming or shrimp ecology. Karthikeyan, WRD executive engineer, said: “We’ve been observing the area for more than two years. Tidal exchanges occur only up to 3 km from Kokila Medu and Kovalam beach. The remaining areas are largely wasteland. In the rainy season, surplus water from surrounding lakes accumulates in the area and eventually evaporates. So we going use that water for our city needs. This project will not affect farming or the shrimp ecosystem. We’re also planning to reconstruct the Buckingham Canal to support farmers and shrimp reproduction.”
Officials from the Fisheries Department said that public hearings were being conducted to gather feedback from fishermen. “Livelihoods of fisherfolk will be protected. The department will ensure adequate safeguards before implementation,” he stated.
Environmental activist Nityanand Jayaraman opined that the State government should focus on recharging groundwater and take responsibility to protect ecosystems such as Kazhuveli, Ennore, and the Kovalam backwaters. “All these play a vital role in the environment and the coastal ecosystem. There are several alternatives to meet Chennai’s water needs, and converting backwaters into freshwater reservoirs is not one of them,” he pointed out.