Ocean flooded the earth even at the time of formation of solar system. It has been known as a blue planet because of its oceans, which covers 70 per cent of its surface said to be the cause of greatest diversity of life in this earth.
There is, therefore, enough water, but not a drop to drink as for Coleridge’s “Ancient Mariner”. One has, therefore, to depend upon the rain which is filtered sea water drawn by the clouds to be showered back to earth. But the voracious appetite for water makes it scarce as seen by a poet:
“The thirsty earth soaks up the rain,
And drinks, and gapes for drink again.
The plants suck in the earth, and are
With constant drinking fresh and fair.”
Water is not only necessary for plants which feed on water, but potable water is necessary for healthy living. Scientists would forecast a global water crisis because of the rapid depletion of surface water.
According to a scientific study, a country or a region is said to experience “water stress”, when the annual water supplies drops below 1700 cubic meters per person per year. Renewable water supply falls much below this limit in many countries, not necessarily limited to the Middle East. Arid regions frequently suffer famines for lack of physical water scarcity.
Water rich India starves for water
India is water rich, ranking with China, Indonesia, U.S., Canada, Russia and Brazil. It is because the glaciers from the high mountains melt during summer causing copious supply of waters in rivers like Indus, Ganges and Brahmaputra along with other perennial rivers from rains in Narmada, Krishna and Cauvery.
But much of the water goes to the sea due to lack of storage resulting in water shortage barring Southern rivers like Cauvery and Vaigai, the waters of which is fully utilised.
There is, therefore, physical scarcity. But there is also economic scarcity for lack of investment in infrastructure or technology to retain the available water and have it distributed evenly throughout the year between different sections of the population in the country.
India remains economically poor. Due to dry environment with inadequate harvesting of rain water, water is scarce. Available water also becomes unusable, since it gets polluted. In fact, one study reports that the holy waters of Ganges at Varanasi is not fit even for bathing due to pollution.
National water grid : Melting of glaciers due to rising global temperature, a world wide phenomenon, causes floods in summer and dries up during other seasons. The lesser availability of fresh water has led to environmental degradation. Water stress harms living things and plants equally, since water is essential for life.
There is a mismatch between supply and use with agriculture being a casualty. Cities like Delhi and Chennai face acute water scarcity while available water gets drained away to the seas for lack of facilities for retention. Enough storage facilities would help rain water harvesting.
It is best assured by National Water Grid as for power under a Central Authority. It will incidentally avoid or reduce the scope for inter-State dispute. Linking of rivers over the years is then a distinct possibility.
National Water Grid can be an Authority in the model of Multi National Regulatory Authority as for river Rhine in Europe or Tennessee Valley Authority in US covering many States. Pollution control can be more effectively ensured by such Authority.
Rain water harvesting : Blessed as India is with fairly adequate water supply, though not uniformly, it need not suffer from water stress, if it has an effective rain water harvesting system.
Storage capacity increase : Ponds are rarely desilted. Holding capacity of even Hirakud dam has gone down by 27.25 per cent due to lack of desilting over the years.
Silts by desilting is a rich source of manure, while retention capacity would be considerably enhanced. Evaporation loss can also be significantly reduced by pouring liquid plastic over the water surface, a technology which has been tried and found successful in some countries.
More water tanks can certainly be built around to collect either waters overflowing the rivers or merely to store water collected through rain water harvesting. Residents of water scarce Saurashtra region in Gujarat have a sizeable source of drinking water supply throughout the year with each house having a water tank. Our farms are ever thirsty.
Thanjavur delta faces uncertain water supply. Even a State like UP fed by gigantic rivers faces 50 per cent depletion in ground water. Pesticide and chemical contaminate ground water. It is certainly possible to neutrailse the chemical damage as has been reportedly done by high-powered water treatment plants.
Moisture preservation : Agro engineering can help to maintain production of our food crops in spite of lesser availability of water by preservation of moisture content after the rains by use of technology. Micro irrigation has been successfully practiced in some countries. Dependence on tubewells is not a solution, since the ground water level goes further down.
Recycling used water : Recycling of water especially the waste including sewage water more so industrial discharges, can be monitored, making available usable water, while curbing pollution caused by discharge from industries and drainages.
Fresh water necessary for the industry can be availed by recycling. The discharge of such water from sewage and industrial discharges into our rivers and the open fields do great damage. River Bhavani has been so polluted that agricultural production in the river-fed areas has been seriously affected.
The deep pond system to collect drainage and industrial discharges are known to have been treated by what is described as anaerobic exercise as is being successfully carried out in Hyderabad where 38,000 litres of waste water per day is processed.
Having clean water with artificial ponds storing treated waters can create wealth by way of prawn cultivation. There are sporadic efforts in different cities with Karnataka known as water shed development projects claimed to be successful by an in increase of 30 per cent crop yield by such better water management.
Desalination – An effective solution
Desalination of saline water has the greatest scope by augmenting the supplies of potable water. Such water can be useful for human consumption apart from irrigation. Valuable by-product like salt will be available. Many sea going ships and submarines use this process of desalination for their needs.
Large scale desalination is done in Israel and United Arab Emirates meeting 40 per cent of their domestic water needs. Reverse osmosis is the process used in Spain. Solar and thermal agency can be used for this purpose.
Atomic power is another valuable source which can help desalination at a lesser cost. Koodankulam atomic plant can undertake desalination to a great extent besides producing energy.
Waste heat from industries causing pollution can be used for creating power. A Canadian firm has announced use of solar or thermal energy by use of ion exchange membranes to remove sodium and chlorine from river water.
Nanotube membranes and other bio-mimetic membranes are also other approaches. Another method is known as sea water green house preventing natural evaporation and condensation process inside a green house powered by solar energy.
Geo-thermal energy can drive desalination. This method is used in most countries to supplement ground water. Freezing technique is still another method. There is world-wide research going on for desalination by physical and chain processes.
Agro-based protection for water
Mangrove trees can have organic growth in sea water. Willow trees are known to absorb salt and other contaminants effectively to aid agriculture.
Research is needed
Scope for research from recycling of waste water from sewage is an on-going exercise, which is being increasingly undertaken but falling very much short of the need. Periyar Maniammai University has a project in collaboration with Thanjavur municipality besides other projects like providing drinking water as one of its object for its scheme of Providing Urban Amenities for Rural Areas (PURA).
All the different steps discussed need examination. The impending water stress is a threat to the economy, if not tackled at a fast pace. Famines which India had to face periodically in the past are likely to be repeated with reported and unreported suicides on the part of agriculturists serving as a warning.
Water and air, though available, was not considered to be a “good” in economic sense as taught from text books in economics, but it is no longer true of water which is extensively bought and sold. What is required is awareness of the seriousness of the problem.
Water is too important a matter to be left to the Government. Non-governmental agencies can help to create such awareness. Our Universities should contribute by undertaking research for which, there is unlimited scope.