More than 400 rivers traverse the length and breadth of India forming at least eight major river systems such as Ganga, Yamuna, Narmada, Tapti, Godavari, Krishna, Indus, and Brahmaputra. They sustain our lives by providing irrigation, drinking water, transportation, power, and grant livelihoods to a large population, besides being an inseparable part of our religion.
Whereas the Ganga flows for 2525 km, Godavari for 1464 km, Yamuna for 1376 km, Narmada for 1312 km, Krishna for 1300 km, the Indus and Brahmaputra, originating in other countries flow for over 1114 km and 916 km in India. All these originate from either the Himalayas and the Karakoram range or the Chota Nagpur plateau and Vindhya and Satpura range or the mighty Western Ghats.
Even as most of the rivers discharge into the Bay of Bengal, some flow through the western part of the country and discharge into the Arabian Sea. However, the Aravalli range, some parts of Ladakh, and arid regions of the Thar Desert have inland drainage. Even as our river system is extensive, it is an irony that we cannot provide safe and clean drinking water to all. Even our irrigation water supplies for sustainable agriculture are in shortage.
Our water resource essentially is due to precipitation, surface and groundwater storage. We get an average precipitation of 46 in per year of rains in 80% of the total area annually, or about 1,720 cubic metres of fresh water per person every year. Other than rains, melting of snow over the Himalayas in winter, feeds the northern rivers to varying degrees. We account for about 4% of the world’s water resources. A person in India needs about 1500 cubic meters of water every year. Even as the need is much less than what we receive, everyone does not have sufficient water in the country. Why? The answer is, much of what we receive flows into the seas and what we use into the nallas as waste, though it is true that the rain we receive is not uniform in time or geography, occurring as it is during the months of June to September. Combined with melting snow in winter, it causes flow variability, leading to flooding in some months and water scarcity and draught in others. Whereas Indo-Gangetic plains suffer from floods due to rains and melting of glaciers, the peninsular states suffer from droughts.
Does the answer to the problem lie in moving water across rivers by a network of reservoirs dams, and canals or to effectively manage the water resources better? Though the idea of interlinking rivers is old, its implementation has several challenges and is relatively new.
Is this a technological challenge? Is this an environmental challenge? Probably both. That such a project is being envisaged by GOI is very welcome. It is the creation of a massive Indian water grid, through the transfer of water from water-excess basin to the water-deficient basin. Realising it means, interlinking 37 rivers by a network of more than 3000 storage dams.
That the Ken-Betwa Link Project is the first under the National Perspective Plan for interlinking of rivers, where water from ‘Ken’ a tributary of Yamuna will be moved to ‘Betwa’ another tributary of the same could be a test case for future efforts. Interlinking rivers could enhance irrigation and groundwater recharge, reduce persistent floods in some parts and water shortages in other. This project is expected to provide annual irrigation of 10.5 lakh hectares, drinking water supply to about 60 lakh people and also generate 100 MW of hydropower. The water grid when ready could generate about 34000 MW of electricity. All that is the theory. Economics of it is more interesting. The power required to lift the water for hydro power is likely to be more than what it might actually produce. One megawatt of hydropower costs over Rs10 crore and produces less than four million units of electricity which amounts to per unit cost of about Rs 8. Reality however, is that there are no takers for power that costs even Rs3 per unit.
Ideally, the project will ensure a minimum amount of water flow in the rivers, greatly helping in the control of pollution, in navigation, forests, fisheries and wildlife protection. Since an improvement accrues in the inland waterways transport system, the rural people could explore an alternate source of income in the form of fish farming. Do Challenges outweigh the opportunities?
What are the Challenges? First, the cost. Estimated to cost almost 6 lakh Crore Rupees delays and unforeseen challenges could double that figure. Second, the engineering of structures at various elevations and terrains can be an engineer’s nightmare. However, massive employment opportunities that accrue is the bright side.
The environmental impact is too serious even as it is sensitive. Wildlife, flora and fauna of the river systems will be displaced affecting the delicate ecosystems that prevail. Since many national parks and sanctuaries are integrated within the river systems, they could also be adversely impacted. Will the project reduce the flow of fresh water into the sea, affecting marine aquatic life? That will be a study for research. Building dams and reservoirs will cause displacement of people. The mental agony they might undergo, may be mitigated through appropriate rehabilitation and an adequate compensation, but will that suffice?
Further, building Dams may not always mitigate floods. Theoretically, they do. However, there are any number of examples to the contrary. Hirakud Dam, Damodar Dam have actually brought floods to Odisha and West Bengal in the past. Getting all the States to agree to interlinking can itself pose a challenge given the interstate river disputes that we have. When building Dams and reservoirs is expanded to the Himalayan component of the project, we could even have disputes with the neighbouring countries.
In as much as saying interlinking of rivers is an idea worth exploring, it entails a large number of dams that will lead to destruction of rivers, forests, wetlands and local water bodies, which are major groundwater recharge mechanisms. Probably, better irrigation practices and watershed management is what we need. Even the National Waterways Project (NWP) which uses only the excess flood water that goes into the sea unexploited, could be a way out. Mark Twain said “The river has great wisdom and whispers its secrets to the hearts of men.” Should we not seek those whispers?