Short Wave - How An Ambitious River Rerouting Plan Could Change India's Weather

Episode Date: July 19, 2024

More than a hundred years ago, a British engineer proposed linking two rivers in India to better irrigate the area and cheaply move goods. The link never happened, but the idea survived. Today, due to extreme flooding in some parts of the country mirrored by debilitating drought in others, India's National Water Development Agency plans to dig thirty links between rivers across the country. It's the largest project of its kind and will take decades to complete. But scientists are worried what moving that much water could do to the land, the people — and even the weather. Host Emily Kwong talks to journalist Sushmita Pathak about her recent story on the project. Read Sushmita's full story here.Interested in more science stories like this? Email us at [e-mail]. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Just a heads up, there is a brief mention of suicide in this episode. If you or someone you know is struggling, call 988. That's the National Suicide and Crisis Line. You're listening to Shortwave from NPR. Planet Earth, our one and only home, is about 70% water. Most of it, ocean. But speckled and traced across the landmasses are lakes and river systems. And those river systems don't always cover the land equally.

A lot of times what happens is you have flooding in one part of the country and you have water scarcity in the other part. This is Shushmita Patek, a journalist based in Delhi. The second largest river in India, the Yomuna runs through Delhi. And in 2023, flooding from the river caused the city to evacuate thousands of people. But there are also arid regions of India, like Bengaluru, a tech hub in the south. It's one of the biggest cities in the country, but it doesn't really have a... a river close by. So what they have to do a lot of times is get river from the Kaweiri River, which is about 100 kilometers away. But sharing the water has caused a lot of conflict.

And as Bengaluru's population increases, Shishmita says they're facing water shortages. Because they've had to bring water from so far away, in tankers, there's actually been a so-called bottom mafia that's come up in that city, actually. In rural areas, farmers can go into massive debt because of crop failure due to these water shortages. Tushmita says the rates of suicide in these communities are high. When these kind of disasters are taking place at the same time, people feel like, why can't we just even that out somehow? And India has an ambitious plan to address this water disparity. Shishmita recently wrote about it in Hackay magazine.

The thinking is, what if you could link different river basins and transfer that extra water to a place that actually needs it? And then the water distribution is more even across the country and everyone is happy. With this plan, India's National Water Development Agency intends to dig 30 links between various rivers that would transfer an estimated 200 billion cubic meters of water around the country east. year. India's river-linking project is the largest undertaking of its kind and would take decades to complete. If successful, it could change how water flows in India forever. In a perfect world, we would have several more, I think, millions of extra hectares of land which could be irrigated. It would improve farmer incomes. It could also be very great for hydropower generation. You could use that extra water. to make electricity.

Shishmita says, on paper, the plan is great and relatively straightforward. You take water from a surplus river basin and transfer to a basin that the government deems in need of water. But in reality, the picture is a bit more complicated when you dig into it. What concerns a lot of independent water experts is what is the basis for that assumption that this river is a surplus and this river is a deficit. And that is not very clear because in India, River flow data is not publicly available.

It's a state secret. A secret that Shishmita wants out. Because moving that much water around has the potential to not only change water movements, but the whole water cycle. And that's what scares a lot of people. Today on the show, India's plan to fundamentally alter their river landscape and how it could change everything,

for people, for wildlife, and for the weather itself. I'm Emily Kwong and you're listening to Shortwave, the science podcast from NPR. Okay, so India's national river linking project is pretty much the most ambitious of its kind. It would connect several of the subcontinent rivers into a mega water grid spanning the entire country. And I learned from your piece that this project is 100 years in the making. How did it all begin? Yeah, so at least one version of it is 100 years old. So in the 19th century, there was this British engineer who was an irrigation expert,

and he wanted to connect some of the rivers in southern India to better irrigate the area, but also to facilitate better transport of goods. But the river linking never happened. But then in the 1960s and 70s, there were a few iterations of the idea, but those ideas also kind of fizzled out. And then in the 1980s is when this current incarnation of the River Linking Project was born, but still nothing happened. Then in 2014, when Narendra Modi became the prime minister, his water minister at the time, you know, very famously said that this is going to be done in a decade. A decade. Obviously, that was not feasible, of course. A decade has passed by, and the construction of the first link is yet to start. But this present government has really taken up this project now. Okay. There are also some potential consequences. And your article spells them out very clearly. Let's go through them now. Starting with the first link in the grid, which is to connect the Ken and Betwa rivers in says.

Central India. It would take about six years. What are some of the immediate known impacts of linking these two rivers on the land, on the people? What would happen? Yeah. So the immediate impacts would be, you know, this link would pass through the Pallna Tiger Reserve in Central India. And so it would submerge parts of that reserve. It would also displace people in that area. Then it would also have. potential negative impacts on some of the protected species in that area. Wulchers, we have a fish-eating crocodile called Gharial, which is, you know, which is only found in South Asia. I think it's expected to submerge some 2 million trees. So those trees would die. And, you know, I asked about this to the National Water Development Authority and they said, you know, we've done deep detailed environmental impact assessments for all the projects that we are going through. So everything is being done while keeping in mind these impacts on the flora, fauna, the people.

But nevertheless, these are concerns that water activists and water experts have told me about. Yeah. And that's just one link, right? Yeah, that's just one link. I mean, the project is proposing 14 links transferring water up north from the Himalienable. and another 16 links transferring rivers further south in the peninsular areas. Yes, that's right. So 30 links in total. And so if you add up all that, it comes out to a lot.

Like there have been some estimates that say that the project could displace half a million people. Oh, my gosh. Wow. And that's considered a conservative estimate. So the impacts are going to be huge on the people, on the marine life, on the animals, on the trees. Yeah. So besides the issue of displacement of people, of destruction of habitat and wildlife,

there is another big potential consequence. And that is the potential to change India's weather because moving river water would affect the water cycle. What is the concern? Yes. So the concern is that this project would actually make drugs. routes worse in some paths instead of helping those drug-prone regions. So a quarter of the rain that India receives is from recycled precipitation. That is when water evaporates from land

and goes into the atmosphere and then falls as rain somewhere else. And what scientists are concerned is that diverting such a large amount of water could interfere with that natural process and it could lead to changes in rainfall patterns. And so I spoke to scientists who did a modeling study on this and they predict if this project goes through, it could reduce rainfall in some dry regions by up to 12%. It would also increase rainfall in some other places, but the concerning thing is that it could make some of those dry regions drier. And the paper that you're mentioning was looking specifically at rainfall patterns during the monsoon season, right? Which is this period of intense rainfall in India.

I remember when I lived there after college, just like it coming down torrentially in like short periods of time. It was like a lot of rain all at once. Yeah, but you're saying, oh, you're in it right now. Yeah. You quote the lead author Tejasvi Chauhan as saying the initial assumption is, is that river basins are independent systems, and output from one can be used to feed the other, but they exist as part of a hydrological system. Changes in one can lead to changes in another.

And that just seems like the big takeaway of this research challenging the river linking project, which is that river basins are connected already through the water cycle, through the atmosphere. And if you were to mess with the connections on the ground, it would change the atmosphere, too, in ways that just we don't fully know. That's exactly right. He said it's not like they're not independent systems. They are all part of this one big hydrological system. And if you tinker with that, it could lead to unintended changes which could really exacerbate the problem rather than help the problem.

Yeah. So Shminta, you mentioned earlier that the hydrological data behind the plan is not being shared openly with, at least. with scientists and water management experts, and that's obviously a problem. So to give climate modelers more confidence in the project, what do you think needs to change? One thing I think that would give independent researchers and experts more confidence is if the government would look into this new research about how the project would affect the rainfall patterns. When I spoke to Tejasvi-Johan, the author of the study, I asked him, you know, after you've

published this study, has anyone from the Indian government reached out to you for, you know, collaborating and seeing how this project would affect rainfall patterns? And at least at that time, he said no one had reached out. You mentioned in your piece that there's other ways to manage water. Why do you think the government has ultimately landed on moving the rivers themselves versus other means for doing water redistribution work? Right. I think. I don't know, maybe I'm speculating here, but I think a river linking project sounds very fancy. It sounds like, oh my God, that is going to be really impressive if you're able to do it. Whereas the other things, rainwater harvesting or recharging groundwater or crop diversification,

they are like simple things that can be done locally. I don't know that the government is doing the river linking project just for the optics of it. But I think that is one part. It is an impressive project on paper. It would be an engineering marvel. Zushmita Patech is a freelance journalist based in Delhi, India. You can read her full piece, The Audacious Scheme to reroute India's Water, at the link in our episode notes. Thank you so much for coming on the show and talking to me about this. Thanks for having me on. Before we head out, I just want to say thank you for listening to Shortwave. If you loved this episode, please follow us on your podcasting platform, consider leaving a review, or even sharing this episode with a friend.

It all helps the show. This episode was produced by Burley McCoy. It was edited by our showrunner, Rebecca Ramirez, and fact-checked by Burley. The audio engineer was Kui-Lee. Beth Donovan is our senior director, and Colin Campbell is our senior vice president of podcasting strategy. I'm Emily Kwong. Thanks for listening to Shortwave from it. NPR.