Prof. Dr. P. K. Jena* in Bhubaneswar, January 21, 2021: Water next to air is essential for all living beings on this planet. The need of water for human beings is increasing with increase in their numbers and development of various socio economic activities. The amount of fresh water available for human consumption is only less than 1% of the total available water on the earth. Again out of this, because of various anthropogenic activities particularly due to urbanization and industrialization, a large portion of water available to the human society is getting polluted.

At present, nearly 70% of water is being used in agriculture, 23% in industry and the rest 7% for drinking and other domestic purposes. It may be mentioned here that, we ‘eat’ much more water than we drink. For example, in a rich country like USA, a person ‘eat’ about 3000 liters of water indirectly through various food items and drinks only 2 to 5 liters per day. This is because most of the food grains, vegetables, fish, meat etc require a lot of water to be produced. For example, 800 – 4000 liters of water to grow a kg of wheat, 2000 – 16000 liters of water to grow a kg of beef and 2000 – 8700 liters of water to grow a kg of cotton, are required.

It is reported that, global food demand may increase by 70 to 90% of the present figure by the year 2040 without any increase in water productivity under the present situation. Therefore, the water for food requirements without any change in diet, from rain fed and irrigated lands, have to be doubled. Further, besides agricultural sector, the demand of water in industrial and domestic sectors is likely to grow appreciably during the years to come. Many parts of the world including India, even at present, have started facing water scarcity and this situation is going to be worse during the next decades unless some remedial measures to improve the water resource are under taken. At present, more than 1.2 billion people (nearly 20% of the world population) are living in water stress region.

The United Nation Development Programme (UNDP) estimates that, by the year 2025, the number of people in water stressed region will be around 3 billion. A recent report co-sponsored by the Consultative Group on International Agricultural Research (CGIAR), Food and Agriculture Organization (FAO), CBD and the RAMSAR Convention (formally, the Convention on Wetlands of International Importance, especially as Water flow Habitat), has warned the human society that, it would be very difficult to meet the global demand for food over the next few decades unless necessary reforms in management of water and agriculture sectors are undertaken.

The following Anthropogenic activities are responsible for scarcity of water

1. Pollution of fresh water resources:

The rapid development of industries and growing urbanization have been responsible for polluting a large proportion of available fresh water due to release of toxic solids and liquid effluents to water bodies without any treatment, making most of the available water unsuitable for drinking and sometimes even for agricultural purpose. For example, Lake Tie the 3rd largest fresh water bodies in China, has been completely polluted by industrial and agricultural wastes and has resulted in debarring over 2.3 million residence to meet their water requirements and forcing them to look for alternate water supply.

2. Disappearance of Wetlands:

Nearly half of the wetlands on this planet have disappeared during the last century due to establishment of industrial infrastructures, roads, development of urban settlements etc. and hence resulted in increasing water crisis. At present, in the world even some rivers no longer reach the sea and nearly 20% of the estimated 10,000 fresh water fish species are now endangered or are being extincted. The situation regarding rapid disappearance of wetlands of India has been worse.

3. Climate change and irregularity of rain fall:

Global warming and climate change have taken place mainly due to polluted atmosphere on this earth. According to Intergovernmental Panel on Climate Change (IPCC) report, the fresh water availability for all human beings is highly alarming. If the global average temperature increases by 30C, another hundred million people will be under water stressed region. The IPCC report also predicted that, by the year 2020, between 75 – 200 million people were likely to be exposed to increased water stress. For example, it is apprehended that, in near future the yield from rain fed agriculture may be reduced by 50% in Africa. The climate change is expected to bring appreciable changes in precipitation pattern and disappearance of glaciers resulting in significant decrease in availability of fresh water for human consumption.

4. Extravagance in use of water:

Agricultural sector alone consumes nearly 2/3rd of the water used by human society and very often, the water actually used is much more than what is required. The main reason is the colossal loss of water due to faulty transportation, leakage, accumulation of excess water in some farmlands and evaporation. Further, the present irrigation system particularly in a country like India, actually consumes only 37 to 50% of water used and the rest of the water is evaporated. In industrial sector, the water used instead of being recycled after proper treatment, is let out to the nearby water bodies and pollute these. Further, a good amount of fresh water is used for purposes like dedusting of roads and washing the vehicles and equipment. In domestic sector particularly in the urban areas, a huge quantity of potable water is used for less important purposes like flushing the toilets, watering the plants in the garden, washing vehicles and dedusting the roads etc.

In view of these, during the years to come besides meeting water crisis, the human beings by using the polluted water would lead a very miserable life. Therefore it is necessary to undertake certain major steps for mitigating the water crisis with zero waste approach:

1. Rain Water Harvesting projects at suitable sites both in rural and urban areas should be planned and implemented scientifically for increasing both the surface and ground water resources.
2. Existing wetlands should be developed and new ones should be created particularly in low lying areas to enhance both the surface and ground water resources.
3. Programmes to keep the rivers and other water bodies away from wastes and effluents from point and non point sources, should be undertaken.
4. It should be mandatory for all mines and major industries to harvest rain water to meet most of their requirements particularly during summer and winter months and recycling the waste water for various purposes. They should also be motivated to develop wetlands.
5. The irrigation system to utilize judiciously the water resources should be modernised.
6. Pricing of water per volume and tariff should be fixed in proportion to the benefits derived by the consuming agencies.
7. High priority should be given to provide drinking water to all, preferably extracted from deep aquifers.
8. A network of water quality monitoring system should be developed both in rural and urban areas and
9. Government agencies at different levels should have the resources and responsibility to implement the above programmes involving all concerned and also to bring awareness amongst the public for proper management of water resources.

*Former Director General, CSIR, India