Industrial Uses
The share of industrial sector is limited to 2 per cent of the surface water utilisation and 5 per cent of the ground-water. Rough estimates indicate that the present water use in the industrial sector is of the order of 15 km3 . The water use by thermal and nuclear power plants with installed capacities of 40,000 MW and 1500 MW respectively, is estimated to be about 19 km3 . The industries are needed to be switched over to water efficient technologies.
By 2050, India expects to be a major industrial power in the world. Industry needs water fresh or recycled. Processing industries depend on abundance of water. It is estimated that 64 cubic km of water will be needed by 2050 A.D. to sustain the industries. Thermal power generation needs water including a small part that is consumptive. Taking into account the electric power scenario in 2050 A.D., energy related requirement (evaporation and consumptive use) is estimated at 150 cubic km.
With the advent of globalization and privatization ,industrial activities water demands share of water is changing rapidly. In addition increase in population and rapid urbanisation also put an additional demand on water resources.
Water treatment plants for all industries emanating polluted water is the need of the hour.
Domestic Uses
The share of domestic sector is higher (9 per cent) in surface water utilisation as compared to groundwater.The National Water Policy has assigned the highest priority for drinking water supply needs followed by irrigation, hydro-power, navigation and industrial and other uses.
Million Development Goals target to halve the proportion of people without sustainable access to safe drinking water and basic sanitation by 2015. The indicators of progress towards this target are;
1) proportion of population with sustainable access to an improved drinking water source (urban and rural);
2) proportion of population with access to improved sanitation.
It is estimated that by 2050, water requirements per year for domestic use will be 90 km3 for low demand scenario and 111 km3 for high demand scenario. It is expected that about 70% of urban water requirement and 30% of rural water requirement will be met by surface water sources and the remaining from groundwater.
Irrigation is needed because of spatio-temporal variability in rainfall in the country. The large tracts of the country are deficient in rainfall and are drought prone. North-western India and Deccan plateau constitute such areas. Winter and summer seasons are more or less dry in most part of the country. Hence, it is difficult to practise agriculture without assured irrigation during dry seasons.
After independence, the Government of India gave high priority to the construction of major irrigation related infrastructure. At present, India has a capacity to store about 200 billion cubic meters of water, a gross irrigated area of about 90 million hectares 2 and an installed hydro-power capacity of about 30,000 megawatts (World Bank, 2005)
Expansion of Irrigation facilities, along with consolidation of the existing systems, has been the main part of the strategy for increasing production of food grains. With sustained and systematic development of irrigation, the irrigation potential through major, medium and minor irrigation projects has increased from 22.6 million hectares (mha.) in 1951, when the process of planning began in India, to about 98.84 mha. at the end of the year 2004-05.