By Sandip Sen
During the 2011 census, India entered the league of water deficient nations. A nation is considered water deficient if the per capita availability falls below 1700 cubic meters per person. The per capita water availability that fell by 15% during the first decade of this century to 1545 cubic meters per person, will be below 1400 cubic meters per person this summer. Though the rate of depletion has reduced in the last few years, we are still consuming much more than is being replenished by nature. And therein lies the danger. We will be leaving a troubled legacy for the next generation unless we take quick remedial actions to reverse the trend.
As per the Central Water Commission, 85.3% of the total water consumed was for agriculture in the year 2000. This is likely to decrease to 83.3% by 2025. India does not spend any money in conserving water consumed in agriculture. Surprisingly, water conservation takes place in the industry and utility sectors, both of which consume less than 5% of the nation’s water.
The Governments, both State and the Central, have traditionally spent taxpayers money generously for flood irrigation. The Finance Minister had in the 2016 budget committed to find Rs 86,500 crores for funding 99 irrigation projects in the water stressed districts of India. This does not help reduce the water stress of the districts because irrigation canals are wasteful. They draw 4 times water from the rivers than what is delivered to the fields. Water utilisation efficiency is less than 30% in the best cases, and half that amount in the worst. Besides, historically, around a third of the irrigation projects start with a lot of fanfare, but do not see completion.
The Union Agriculture Ministry statistics says that 48.6% of India’s substantial 140 million hectares of farmland are irrigated. Fields in Punjab and Haryana, Uttarakhand and western Uttar Pradesh where irrigation canals are in abundance see lavish use of water from the Himalayan rivers. This has reduced the flow of water downstream and increased water scarcity as the rivers reach the plains. Similar is the situation in the Kaveri and Godavari basins. As a result, Bundelkhand, Marathawada and the Deccan region are areas of acute water distress. The lengthy court litigation and the political war of words between Tamil Nadu and Karnataka would not have erupted over Cauvery water sharing had water been efficiently used for agriculture.
Desert nations have cut down farm water consumption
So, how does India solve its water crisis? And, how does it do so without hurting the poor?
It is not that solutions are not available. Water deficient desert nations like Israel, living under extreme climatic conditions, are today water surplus. Though everybody feels that it’s giant desalination plants that have brought about the reversal, that is only part of the story. In 2008, the West Asia nation living along the ‘Fertile Crescent’ was facing a decade long drought. At that time, Israel realised that the water withdrawals for its farmlands was unusually high. The water level at its largest freshwater lake, the Sea of Galilee, was inches higher than the black line. If it fell below that mark, irreversible salt infiltration would flood the lake and ruin the fresh water source for ever. Israel imposed a year of unpopular but necessary water rationing and most farmers living in that fertile belt lost a year of crops. This had its political ramifications. But a massive ad campaign across Israel was conducted explaining people how the water crisis was affecting the nation and how it would be tackled. This was followed by a nationwide education campaign.
During that year, it also changed the method of irrigation. Israel started using recycled, slightly brackish water for irrigation. Today, 80% of Israel’s wastewater is recycled for agriculture use. It solves twin problems. The brackish water has lower treatment costs. It is good for agriculture but not good for human consumption without further treatment. Importantly, it gets waste water recycled for consumption in the farms, and the sludge does not contaminate the fresh water sources.
Israel also migrated from open water canals to piped supplies and drip irrigation. This in the long run saves almost three fourths of the water used for irrigation done through open canals. Along with measures taken for rainwater harvesting, it has ensured that water consumption in the desert state has not gone up during the last decade. Investing in drip irrigation has ensured lower consumption of both water and fertilizer. Besides, crop yields have been nearly 15% higher than flood irrigated crops. Today Israel has the world’s highest crop yield per cubic meter of water consumed. It also has no rising water consumption because of conservation. After they implemented these conservation measures, Israel added large desalination plants to create a surplus water nation.
India needs to change both recycling and farm water supply policy
To reduce the water crisis in India, we need to change both our recycling as well as supply mode. Integrating recycling water into agriculture supply will solve two major problems.
75% of water pollution from domestic waste water is today discharged untreated into local water bodies and rivers. This amounts to around 40,000 million liters per day MLD from its 300 odd cities. Irrigation with waste water may cost less because of lower purification levels and also because crops serve as bio- filters and waste water contains nutrients. At the same time, the water must remove toxicity that is harmful.
Since last two decades, the Indian Government has been spending sizable amount of tax payers money each year in recycling the urban waste water. It has also been spending liberally on cleaning the Ganga as well as other rivers. Out of the 816 municipal sewage plants listed by CPCB in a December 2015 release, only 522 were operative. Even there, the quality of water at best confirms to Class C (fit for drinking only after treatment and disinfection). All the treated water could perhaps be eminently suitable for agriculture use if India developed the mechanism of supplying treated waste water to farmlands.
In comparison to lined irrigation canals, large diameter prefabricated concrete pipes are both cheaper and quicker to instal. Besides the exit points are more controllable. It is not possible to put submersible pumps in piped water and that itself would save a lot of water and energy. Instead, more efficient solar powered drip irrigation kits could be developed and marketed across India, giving the farmer an option to use optimum water and energy for his crops.