Outcry over plan to turn part of Adi Ganga in Kolkata into drain

The West Bengal Housing Infrastructure Development Corporation (HIDCO) is planning to turn a 1 km stretch of Adi Ganga, the original channel of the holy river flowing through Kolkata, into a drain, with concrete pathways above it.

Adi Ganga, also known as the Gobindapur Creek, Surman’s Canal and (currently) Tolly’s Canal, has long been a de facto drain, buried under garbage and the metro rail network. HIDCO’s plan, which affects the Kalighat Bridge-Alipore Bridge section, will make it a drain by design, experts fear. Last month HIDCO floated a tender seeking a consultant to facilitate this process.

A major chunk of funds to revive the river has been released under the National Mission for Clean Ganga (NMCG), according to the experts. “Should we consider turning the national river into a drain as rejuvenation?” environmental activist Subhas Datta told the website DownToEarth.

Main flow to sewer

Adi Ganga, which is around 75 km long from the point it breaks from the main channel of Ganga at the tip of Kolkata to the point it meets another river on way to Bay of Bengal, had earlier been encroached upon at several places. Out of the entire stretch, about 13 km is in the city.

Between the 15th and 17 centuries, Adi Ganga was the main flow of River Hooghly; today it is a sewer. The river course has been systematically degraded, with encroachments at several points. The construction of the metro rail has been a major contributor to this.

HIDCO plans to direct the course of dry weather flow (flow of sewage beyond monsoon months) by constructing concrete channels, as part of the Alipore Area Development Project.

“The main emphasis will be to guide dry weather flow (Adi Ganga) through a rectangular reinforced cement concrete (RCC) u-trough (channel). There will be an immediate RCC floor at the top of the U-Trough,” the tender document read.

Both ends of the stretch will be controlled through sluice gates, it added. This indicates the stretch will be cut off from the main channel of Adi Ganga. It also means that the entire river will be cut into three parts within the city itself.

Why experts are worried

Such a step will effectively kill the river beyond Kalighat, where the drain will end, river experts pointed out. This is because tidal water will most likely be unable to reach the nine-km-long lower part of the river.

“Effectively, the step means guiding the river into a box drain for the stretch with an upper cover,” said a drainage expert.

The river stretch is not supposed to be a dry weather flow channel in the first place and should have been revived, they complained. “Huge funds are being pumped under the National Mission for Clean Ganga to stop sewage flow into the river,” the expert said.

The National Green Tribunal (NGT) has also passed several orders on this matter, the expert noted.

The proposal is unlikely to find favour with the central body, an expert linked to NMCG said, as cited by the report.

Stopping the stench

The state government plans to construct several high-end residential buildings under Alipore Area Development Project. it added. The step is meant to stop the stench arising from the channel from spreading into the surrounding areas and to hide drainage outlets from residents of these projects, the experts said.

The project is already under the scanner for possible environmental impacts and stresses, they added.

One expert said the proposed drain is “absurd and a blatant effort to hijack the river officially”. It’s strange that when the Kolkata Municipal Corporation is being given hundreds of crores to clean up Adi Ganga, another wing of the government is planning to shackle it within a drain, he added.