Two weeks ago, the Supreme Court told the government that at the rate it was going, it would take it 200 years to clean up the Ganga. Last Tuesday, the centre admitted that the plan was indeed a little long term ‒ but they estimated that it would take only 18 years.

The centre’s plan, as presented in court, is to address the problem of sewage flowing into the river. It plans to spend Rs 51,000 crore on waste-water treatment at 118 urban centres along the 2,525-km river.

“The gap between waste-water generation and the capacity of treatment plants is about 1,515 million litres across the Ganga,” said Kalyan Rudra, a member of a Calcutta High Court-appointed Ganga Monitoring Committee. “This means that even if all the treatment plants along the river work to full capacity, 1,515 million litres of waste water will remain untreated.”

A major problem for treating sewage is that old lines are not necessarily built to account for treatment.

Redesign required

“In the case of West Bengal or in any other major cities, diversion of sewage into treatment plants failed because this meant a total redesigning of the sewage lines of city,” Rudra said. “Even if you build two or three treatment plants in cities like Benares, Kolkata or Patna, you will still have to redesign the entire sewage line so that it leads to the plant. That is the only case in which you can treat waste water.”

Experts say that if the government is really serious about the overall health of the river, it needs to look well beyond sewage treatment.

“When the river flows, flora and fauna thrive,” said Gopal Krishna, of the Toxics Watch Alliance. “But when it stagnates, flora and fauna begin to decay. Because of depletion in water quantity, the first thing that happens is deterioration in water quality. And what is cleaning the Ganga about? It is about water quality.”

One of the most significant problems with the Ganga is that it does not flow uninterrupted from source to mouth. A series of dams interrupt it all along its course, artificially creating water scarcity in different pockets along the river.

“Dams and barrages have a serious impact on a river,” said Manoj Misra of the Yamuna Jiye Abhiyaan. “They break the continuity of a river's flow, which is the essence of a river system.”

Intensifying pollution

Dams and barrages impact areas upstream and downstream of the river hugely, he said, but in a different manner. Upstream, dams cause inundation of lands and a build-up of silt deposits. Downstream, they dry up the river.

Another consequence of dams is that they also trap polluted sediment behind them. This is especially true of Himalayan rivers. The Ganga itself has the largest sediment load in the world. An embankment built along the dam might last only 25 years before the sediment builds up enough to engulf it entirely. The sediment trapped by dams only deepens its polluted state.

Treating pollutants entering the river is only a part of the government’s ambitious plans for the river. One of its much feted ideas is to make the Ganga navigable for ships to transport coal and also to build 16 more barrages along the way to facilitate this.

(The previous government had proposed to build 300 dams, until met with opposition. The status of these dams is unclear.)

But for there to be a waterway, there needs to be water in the river.

“There are demands for irrigation and industry. With all this, there is hardly any water left flowing in the river,” said Nachiket Kelkar, an ecologist studying for his PhD at the Ashoka Trust for Research in Ecology and the Environment, who has been surveying the Ganga.

He added, “Water is either locked up or released only during the flood season. So from March to May there is acute water scarcity, not just for the river flow itself, but for the people using it. The Gangetic basin actually has a negative ground water deficit in those months.”

Sediment deposits

Another problem here is the amount of sediment they will have to excavate to create a deep enough waterway.

“They propose to excavate a navigation channel from Allahabad to Haldia,” said Rudra. “How will the river function? If you create 16 pools of water and excavate around it, they will have to deposit the sediment somewhere. The banks of the Ganga are either agricultural fields or densely populated.”

“I believe the government has a very profound lack of understanding of how rivers function,” added Rudra. “Unfortunately in this country, politics dominates over science. What is scientifically correct is often not politically correct.”