At present, available statistics on water demand shows that the agriculture sector is the largest consumer of water in India. About 83 per cent of the available water is used for agriculture alone.
The quantity of water required for agriculture has increased progressively through the years as more and more areas were brought under irrigation. Since 1947, the irrigated area in India rose from 22.60 to 80.76 mha up to June 1997. Contribution of surface water and groundwater resources for irrigation has played a significant role in India attaining self-sufficiency in food production during the past three decades, but it is likely to become more critical in future in the context of national food security.
According to available estimates, due to judicious utilization, the demand on water in this sector is projected to decease to about 68 per cent by the year 2050, though agriculture will still remain the largest consumer.
In order to meet this demand, augmentation of the existing water resources by development of additional sources of water or conservation of the existing resources through impounding more water in the existing water bodies and their conjunctive use will be needed. Figure 6 depicts the driving forces of both water supply and water demand.
In 1999, the National Commission for Integrated Water Resources Development estimated the water requirements for the years 2010, 2025 and 2050 at the national level