Conserving the last drop:-

This editorials is part of 6 series essay that explores the issues of water scarcity and provide few good case studies.

Disclaimer :-  This editorials are given as case studies, although the names of the people are not important from exam point of view, however few datas are important and they are highlighted.Keep  5  things in mind while reading this case study :-

1. Where it is happening – the geographical extent
2. Why it is happening  ?
3. What are the impacts ?
4. What can be the solution ?

Here are the 6 parts :-

1. Drilling for their Lives
2. Telengana’s Tanker economy
3. Drinking water, sipping Poison
4. Interlinking, an idea with flaws
5. Scarcity in Mettur’s vicinity
6. Conservation – lessons form ancient India

Part -4 – Interlinking, an idea with flaws

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.

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  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,.

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  argues that river interlinking will cost the government about Rs. 10 trillion and the spate of projects that involve connecting 14  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, they also threaten to obstruct the natural ecology of rivers.

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.

However 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,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.

Part 5 will be published tomorrow.