India’s incredibly ambitious—and some say, incredibly reckless—Rs11 lakh crore ($168 billion) project to interlink its rivers is finally underway.

On Sept. 16, the Godavari and Krishna rivers—the second and the fourth longest rivers in the country—were linked through a canal in Andhra Pradesh. The project was completed at a cost of Rs1,300 crore ($196 million). A second scheme, the Ken-Betwa river project—estimated to cost Rs11,676 crore ($1.7 billion)—is currently under development, with completion likely by December this year.

This is a part of the Narendra Modi government’s plan to revive the river-linking project, which was first envisioned in 1982, and actively taken up by the Bharatiya Janata Party government under prime minister Atal Bihari Vajpayee in 2002.

Here is how the river-linking project works: The big idea is to connect 37 Himalayan and peninsular rivers. So, water-surplus rivers will be dammed, and the flow will be diverted to rivers that could do with more water. In all, some 30 canals and 3,000 small and large reservoirs will be constructed with potential to generate 34 gigawatt of hydroelectric power. The canals, planned between 50 and 100 meters in width, will stretch some 15,000 kilometres.

“If we can build storage reservoirs on these rivers and connect them to other parts of the country, regional imbalances could be reduced significantly and lot of benefits by way of additional irrigation, domestic and industrial water supply, hydropower generation, navigational facilities etc. would accrue,” India’s National Water Development Authority describes the project on its website.

The project is expected to create some 87 million acres of irrigated land, and transfer 174 trillion litres of water a year. Also, half a million people are likely to be displaced in the process, according to a report (pdf) by Upali Amarasinghe, a senior researcher at the International Water Management Institute.

Ecologists and environmentalists warn that the project is imprudent and dangerous, especially since there is little clarity on the ultimate impact on such a massive undertaking.

Quartz interviewed a number of Indian environmentalists and activists, and here is what they had to say about this project:

“A river isn’t a pipe that we can control.”

— Dr Latha Anantha, director, River Research Centre

Firstly, there is no concept of deficit and surplus. That’s what we are making it to be. A river has a natural course and for years it has been following that. Who are we to say it has a surplus and it has a deficit? The river will carry as much as it can. Secondly, a river isn’t a pipe that we can control. You can’t compare a Ganga to another. It has different characteristics. And when you build a canal to flow the water that is diverted, you are displacing far too many human lives and the eco-system. For instance, in the Ken-Betwa project, the core area of the Panna national park will be affected. The government, wanting to do the project for political reasons without any sort of clearances, is basically, redrawing the entire geography of the country. Even if there is a surplus and flood, every river needs that. Thats how the natural ecosystem works. You can’t block it.

“There is no scientific basis for this”

— Himanshu Thakkar, coordinator, South Asia Network on Dams, Rivers and People

How do you conclude that river-linking project will be good? There have been no scientific basis to say that. All you have is an incomplete study that says this is good for the country. One has to exhaust all options and potentials before concluding that river-linking is the best alternative. Exhaust options such as watershed development, rainwater harvesting, ground water recharge, optimising existing infrastructure and cropping methods and then we can conclude that water-linking might be good. But there has been no assessments done. For instance, look at Maharashtra and Andhra Pradesh. The Marathwada region in Maharashtra is the worst drought-hit state in India today, and belongs to the Godavari basin. But at the same time, you want to divert water from Godavari to Krishna. It doesn’t make sense. There has to be assessment done because there is huge impact on the nature.

“Horrifying and ill-planned.”

— Medha Patkar, national convener, National Alliance of People’s Movement

This entire push for the river-linking is horrifying and is ill-planned. The hydrology of the rivers are changing and we are ignoring the cultural and ecological significance. Even the cost that the government is talking about, of Rs5.6 lakh crore ($85 billion) is based on old reports. Now the cost would be much more and would at least be Rs10 lakh crore. The bigger question is, who is going to fund this? Is the private sector going to do that? And if they do, they will only have interest in the land. The other thing is, there is no social impact assessment done on the livelihood of the people who are living in these areas. They don’t even engage the gram sabhas while taking decisions.

“River-linking is a social evil, economic evil”

— V. Rajamani, professor emeritus, Jawaharlal Nehru University, New Delhi

The interest in river-linking now is due to the big bucks involved in it for dam builders. A canal is not a river and it cannot support an ecosystem. What happens to everything that is living in the river? When water flows, there are a number of factors associated with it. There are micro organisms and there are marine life. We are taking away all of that by building dams and diverting water for something that is not even natural. When you build dams, you are displacing too many people. What will they do? They land up in slums in cities. River-linking is a social evil, economic evil and will ultimately lead to collapse of civilisation.

“These projects are not viable.”

— Sushmita Sengupta, deputy programme manager, Centre for Science and Environment

The basic concept of linking of rivers in India is to transfer water from where there is a surplus to a place where there is a deficit. But when such transfer of water takes place, there is a significant community displacement that happens along with it. Another major issue in India vis-a-vis river-linking is that water is a state subject. Now states that have surplus water are not ready to give it to other states and there is a huge logjam which is cropping up time and again because of this. Even though the government is thinking of intra-state river-linking processes—where a river of a state is connected to another on in the same state—the environmental issues relating to these projects are very huge. There is a big problem of desilting and there is no clarity on where the silt be actually dumped. Will it be somebody’s farm and will the farmers be affected or not? The government has not come clear on any of those points. So considering these environmental and community issues, overall I don’t think these projects are really viable.

Itika Sharma Punit contributed to the report.