Interlinking of rivers: an idea with flaws
Published on by Water Network Research, Official research team of The Water Network in Academic
The stark differences in water availability in the river basins in the country has thrown up the idea of interlinking of rivers, but this project is not foolproof.
The initial plan to interlink India’s rivers came in 1858 from a British irrigation engineer, Sir Arthur Thomas Cotton. Since late last year, the scheme has been implemented by the Central government in several segments such as the Godavari-Krishna interlink in Andhra Pradesh, and the Ken-Betwa interlink in Madhya Pradesh. The evidence on the benefits of the interlinking scheme is mixed. On the one hand the project is built on hopes that it will boost per capita water availability for 220mn water-hungry Indians. The scheme also envisions an area more than twice the size of Andhra Pradesh receiving additional water for irrigation and to eventually even out the precarious swings between floods and droughts. Yet even as the project moves forward it must consider the risks at hand, which include the possibility that it could displace nearly 1.5 million people due to the submergence of 27.66 lakh hectares of land; and concerns surrounding escalating cost projections, which have reportedly jumped to something closer to Rs. 11 lakh crore. Part five of the six-part series focusses on river basins.
For most of March and April, Thursdays are dismal news days for India’s Central Water Commission (CWC), the nodal body responsible for commissioning dams and major water-storage bodies, and monitoring their health.
On that day they make public the state of water storage in India’s principal reservoirs and the general news has been that water has plummeted to historic lows, both in terms of the corresponding period of last year and also compared to the average storage of last ten years during the corresponding period.
Their view of river basins is not very different.
For the purposes of monitoring, the CWC divides India’s rivers into 12 major basins. The largest of them – the Ganga basin – is not the worst case. The CWC figures for April 28 show storage to be 7.8 BCM. While that may be less than the 10.6 BCM storage at the same time last year it is 22.8 per cent more than the decadal average of 6.35 BCM.
However the numbers for the Indus basin and the Krishna basins are far from inspiring. The Indus this year is 35 per cent and the Krishna 67 per cent less than their 10-year normal.
The most updated estimates of per capita water availability in India’s river basins show stark inequality. The Brahmaputra basin, for instance, can annually support nearly 13000 cubic metres per person, whereas the Mahi has a scarce 260 cubic metres per person.
Inter-basin inequality
This well-known inequality in distribution is the reason why engineers at the CWC and India’s water resources ministry have urged for the diverting water from the Ganga basin, which floods even in drought years as it did in Assam this year, through a complex of canals and medium-sized storages into less-endowed rivers.
“Storage provides you flexibility in the uses of water. Dams are required but whether they must be big or small is something that must be decided based on the region they are located,” said G.S. Jha, the Chief of the CWC, in an interview.
Being able to successfully transfer water through the interlinking of rivers will mean 35 million hectares of irrigation, raising the ultimate irrigation potential from 140 million hectare to 175 million hectare and generation of 34000 megawatt of power, apart from the incidental benefits of flood control, navigation, water supply, fisheries, salinity and pollution control, according to the Central government.
Perils of linking rivers
Yet not all are convinced of the feasibility and benefits of the proposal. Water Resources Minister Uma Bharti argues that river interlinking will cost the government about Rs. 10 trillion and the spate of projects that involve connecting 14 for Himalayan rivers and 16 in peninsular India implies that 15,000 km of new canals will have to be added to relocate 174 BCM of water.
Apart from the massive displacement of people that such projects will bring about, says activist Himanshu Thakkar, they also threaten to obstruct the natural ecology of rivers.
Former Planning Commission member, Mihir Shah noted in a critique of India’s river-interlinking projects in the Economic and Political Weekly that in the Krishna river basin water storage in major and medium reservoirs has reached total water yield with virtually no water going into the sea in low rainfall years.
Since the Ganga basin’s topography is flat, building dams would not substantially add to river flows and these dams could threaten the forests of the Himalayas and impact the functioning of the monsoon system.
Climate change is another concern. In interlinking systems, it is assumed that the donor basin has surplus water that can be made available to the recipient basin.
“If in future, this basic assumption goes haywire for any system, wherein our perennial systems – mostly Himalayan – don’t retain the same character of being donor basins, then the whole concept goes for a toss. This will happen if the glaciers don’t sustain their glacier mass due to climate change,” explained A. Gossain, Professor at IIT Delhi who researches Indian water resources.
Professor Gossain however notes that alternatives such as curbing demand by efficient utilisation of existing water resources should be prioritised before making big-ticket investments in river interlinking.
Questions of storage needn’t always be seen in the light of big dams, adds Shashi Shekhar, Secretary, Ministry of Water Resources. The judicious use of canal water, growing crops that were appropriate to a region, encouraging drip irrigation and reviving traditional systems such as the use of tanks are also as important as creating new storage.
“Drought prone systems have a traditional network of tanks that were always employed for harnessing water during crises…a focus of the government is also to better use these systems across the country,” he said.
Source: The Hindu
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2 Comments
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Let us take Peninsular rivers. They all are seasonal depending only on rainfall as the source of water. They are fast flowing and flow through mostly undulating landscape. They have excess water in Monsoon and dry in summer if there is no storage and regulated flow. Though all the rivers have dams and reservoirs, due to increasing water demand and a year or two drought years, the existing storage capacity is falling short. There is always a marked shortage of water in certain areas like Marathwada, Vidarbha in Maharashtra, Bidar in Karnataka and Telangana.
The Himalayan Rivers -
1. Indus basin has no excess water left for diversion out of Punjab, Haryana and Rajasthan. It may infact be deficit of water requiring replenishment from other sources like the Ganga system.
2. Ganga and Brahmaputra river systems though perennial also have monsoon rainfall as their main source of water. The glacial water component is much less as compared to the Indus. Meaning, these rivers are much leaner during summers. Therefore we cannot depend on diverting Ganges / Brahmaputra waters to other river systems during summers.
In order to overcome this, larger dams, reservoirs are needed to store monsoon rain water both on the Himalayan and Peninsular rivers. The present storage capacity is inadequate as we can see this year. Apart from the river systems, the Western coastal plains is a peculiar case. Though it gets excess rainfall close to 200 cms or more. The water quickly flows into the sea and all the small rivers get dry by December. Most of the land though fertile can be cropped only once due to paucity of water / irrigation. A series of reservoirs should be constructed at the foothills of the Western ghats for the storage which can feed a canal running right from Surat over Narmada in the North to Vembanad Lake in Kerala should be conceived. Excess water from this system can be diverted to North Gujarat, South Rajasthan,
River linking through barrages / canals will help in properly utilising the water resources. It can be used efficiently for flood control; providing water to rain deficit regions, etc.
The need of today is to develop a grid plan (like NTPC's for electricity) of dams, reservoirs, barrages, inter-link canals for entire India, with the aim that if required water from any swollen river can be diverted to another river or area - eg. say Kosi river water could be diverted to distant Bidar in Karnataka or Brahmaputra to Saurashtra. -
The Ministry of water resources, Ground water department and Agriculture Ministry of state and Union Govt. are adopting anti people policies, which are expected from colonial rule like British colonial rule in India. These ministries and departments are doing every effort to deplete precious ground water of India. By the thought of Interlinking of rivers, they are deceiving people of India, so that people of India may not criticise their anti people policies. It is high time that honourable supreme Court of India may take suo moto notice of anti people policies of these ministries and discuss them as a PIl. Alternately I appeal to NGO's of India like Mr Prashant Bhushan, ,Anna Hazare etc to file a PIL in Supreme court to expose these ministries for their anti people policies and get them corrected. Otherwise it is feared that the people of India, who are dependent only on ground water to fulfill their drinking water needs will die.