A plan to interlink India’s rivers, which has been floating around the subcontinent for decades, will likely get approval to begin very soon, reports TV Padma at New Scientist. The project, called the Interlinking of Rivers (ILR), would connect the Himalayan Rivers of northern India with the rivers in the rest of the country through the use of 30 huge canals and a system of 3,000 dams. If accomplished, it would create a 12,500-kilometer long river network—the largest in the world.
Water is becoming an increasingly dire problem for India as drought becomes more frequent and the rapidly growing population places greater stress on the water supply, reports Vidhi Doshi at The Guardian. This year alone, 330 million Indians were impacted by drought, and water had to be delivered by train to the state of Maharashtra.
One of the biggest issues is the uneven distribution of water. India gets a fair amount of rain, but most of it comes during the monsoon season in the late summer and fall, which floods rivers in the southern part of the country but leaves many areas dry or arid for the rest of the year, Doshi writes. The spotty water resources impact agriculture in much of the country—even drinking water is scarce in some areas during the summer.
Enter the ILR. The idea is to link rivers in the Himalayas, which flow year-round, to the rest of the country to provide a constant water supply while preventing floods. The proposal isn't new, Doshi reports. Engineers in the British Empire kicked the idea around for several years. In the early 1980s the administration of Indira Gandhi proposed the project, but it was rejected by several states.
Prime minister Narendra Modi is providing the push for the current incarnation of the project. It has already been approved by the government and supreme court, and as soon as the environment ministry signs off on the projects, the ILR can begin in earnest.
If the scheme works as planned, the benefits would be significant. Manu Balachandran at Quartz reports that the $168 billion project would irrigate 87 million acres of land, provide 34,000 megawatts of hydropower, and redistribute 174 trillion liters of water.
Not everyone is thrilled by the project, and many researchers believe it is a fool’s errand. Earlier this year, researchers from the Indian Institute of Technology found that changing climate patterns mean that some of the underlying assumptions about rainfall and river volumes may not be accurate in coming years. “One of the plans of interlinking of rivers is supplying water from a surplus basin to a deficient one,” Professor Subimal Ghosh tells Snehal Fernandes at the Hindustan Times. “But if the surplus basin itself shows a declining trend of water availability, they will find it difficult to both meet their own demands and also supply the quantum of water committed to the deficit river basins. The project may not be sustainable.”
Others object to disrupting the natural ecosystems of up to 37 major rivers. Rivers move sediment that feeds marine ecosystems, recharge groundwater supplies create habitat for fish and other species. Flooding also adds nutrients to the soil in many parts of India and helps flush salt water from ground water, which can lead to desertification. Disrupting those processes could have huge environmental impacts. “A river is not just a natural pipe through which water flows,” geologist Chittenipattu Rajendran at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, tells Padma. “It carries deposits and sediments. Dams trap sediments that are critical to habitats downstream.”
Latha Anantha, from the River Research Centre, tells Doshi that the project is very short-sighted, and will probably not deliver what is promised. “The government is trying to redraw the entire geography of the country. What will happen to communities, the wildlife, the farmers who live downstream of the rivers? They need to look at a river not just as a source of water, but as an entire ecosystem,” she says. “They will have to dig canals everywhere and defy the ecology of the country. It is a waste of money and they have overestimated how much water there is in the rivers they want to divert.”
The first pilot project in the ILR, a link between the Ken and Betwa rivers was approved by the Ministry of the Environment, Forest and Climate Change in September. The act will destroy 100 square kilometers of the Panna Tiger Reserve in Madhya Pradesh.