We’re fast running out of water

A Narayanamoorthy /P Alli
More crop per drop: That’s what SRI rice is all about
Promoting water saving technologies in paddy and shifting to pulses and oilseeds can make a big difference
The UN has selected “water and jobs” as the central theme for this year’s World Water Day, which is being celebrated annually throughout the world on March 22. But, water resources are under more serious threat today than ever before. Water is reportedly the world’s most exploited natural resource.
As per the latest National Aeronautics and Space Administration (NASA) satellite data, more than half of the Earth’s 37 largest aquifers are running too fast to be replenished. This is extremely troubling, considering the fact that we draw about a third of world’s water from the aquifers.
The United Nation’s World Water Development Report on Water for a Sustainable World (2015) has made a startling claim that world would face a 40 per cent shortfall in freshwater in as soon as 15 years.
The water tables are also dropping globally at an alarming rate. For instance, NASA’s findings suggest that India’s water table is declining alarmingly at a rate of about 0.3 metres per year. Falling water tables has prompted various users to use expensive deep-water equipment which has consequently put the groundwater under severe stress.
At the backdrop of such a precarious situation, the World Economic Forum in its Global Risks Report (2016) has cited water crisis as one of the three biggest challenges of the world.
A latest study has backed up these findings estimating that about four billion people face scarcity of water and among them about one billion live in India.
So scarce is the global water supply that the United Nations World Water Development Report on Water for a Sustainable World (2015) has reportedly warned that by 2030 only 60 per cent of the world’s demand for water will be met by the existing resources at the current rate of use.
Climate change is expected to worsen the situation further by distorting the geographical and time-period distribution of rainfall resulting in floods and excessive dry seasons.
Alarming withdrawals
As per a very crucial study by Mekonnene and Hoekstra (2015) of the University of Twente, Netherlands, about 80 per cent of Indians face a severe scarcity of water for at least a month every year. And as per the United Nations World Water Development Report about 22 out of 32 Indian cities face daily water shortages.
The precious groundwater resources are alarmingly under severe stress today. Of the total 5842 blocks assessed by the Central Ground Water Board (CGWB), about 802 are over-exploited, about 523 are semi-critical and about 169 are critical.
Indiscriminate withdrawals have been reported from the agriculturally well-developed states of Tamil Nadu, Andhra Pradesh, Uttar Pradesh, Punjab and Haryana.
Water scarcity is most likely to threaten the country’s food security as well. Farmers in the major growing regions of the country are unable to manage their crop cycles due to unavailability of both surface and groundwater.
In some regions, such as in Marathwada region of Maharashtra, acute water scarcity has driven large number of farmers to sell off their lands and migrate to cities in search of better opportunities. Is the crisis just because of the disturbances in the demand and supply curve or is it due to the mismanagement of water resources?
Besides increased population pressure, constant competing demand for water from household, agriculture, industry and energy sectors reportedly contribute to declining water availability.
According to the data published by the Ministry of Water Resources, the annual groundwater draft is 243 BCM out of which 221 BCM is for irrigation use and 22 BCM is for domestic and industrial use. It is reported that farmers tend to overdraw groundwater by keeping their pump sets switched on for long periods as they fear that power cuts may interrupt the water flow.
As a result, inadvertently they often flood their fields that are causing further distress to water resources. What can we do to bring this down dramatically?
More yield with less water
In order to secure the future of India’s water resources, it is very important that certain steps be taken immediately especially in agricultural sector which consumes about 85 percent of the available water today. Introduction of more efficient water management is the need of the hour.
There is an urgency to compute the water requirements of different crops and introduce water saving measures such as drip irrigation, sprinkler and system of rice intensification for irrigation on large scale.
The Economic Survey 2015-16 has also underlined that it is imperative that the country focuses on improving efficiency of water use in agriculture in the form of adopting such water saving technologies.
Various field level investigations prove that these technologies besides bringing about a substantial increase in crop productivity, also save about 50 per cent of water and electricity per acre. In States such as Andhra Pradesh, Gujarat, Maharashtra and Tamil Nadu the drip irrigation method is found to be working very well.
Crop distribution needs a drastic change wherein the water-stressed states can shift from cultivating water-intensive crops like paddy and sugarcane to pulses and oilseeds which would require less water, but generate more profit.
Climate experts have predicted that there will be fewer rainy days but in those days it would rain more, increasing the chances of flooding. Therefore it is imperative for India to develop capacity to store and even transport water.
In this regard the International Water Management Institute (IWMI) suggests that a mix of storage options, including aquifer recharge, restoring natural wetlands, enhancing soil moisture and small ponds and tanks would complement reservoir storage to increase water availability. Rainwater harvesting is one of the cheapest and easiest ways of augmenting water stock.
Despite an existing regulation which makes rainwater harvesting mandatory for all new buildings with a roof area of more than 100 square meters, few do it.
Let us pledge to conserve and manage tomorrow’s water more sustainably that is being used to meet today’s need.
Narayanamoorthy is professor, Alagappa University, and Alli is assistant professor, Vellore Institute of Technology.
Today is World Water Day
(This article was published on March 21, 2016, source : http://www.thehindubusinessline.com/opinion/were-fast-running-out-of-water/article8381809.ece?homepage=true)
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