India's Water Wealth
Water is one of the most important renewable natural resources for supporting life. With the increasing population of India as well as its all-round development, the utilization of water is also increasing at a fast pace. On an average, India receives annual precipitation (including snowfall) of about 4000 km3 . However, there exist considerable spatial and temporal variations in the distribution of rainfall and hence in availability of water in time and space across the country. It is estimated that out of the 4000 km3 water, 1869 km3 is Average annual potential flow in rivers available as water resource. Out of this total available water resource, only 1123 km3 is utilizable (690 km3 from surface water resources and 433 km3 from ground water resources). The water demand in the year 2000 was 634 km3 and it is likely to be 1093 km3 by the year 2025. Due to rapid rise in population and growing economy of the country, there will be continuous increase in demand for water, and it will become scarce in the coming decades ( Refer Table-1).
Table-1:Water Availability Facts at a Glance
| Area of the country as % of World Area | 2.4% |
| Population as % of World Population | 17.1% |
| Water as % of World Water | 4% |
| Rank in per capita availability | 132 |
| Rank in water quality | 122 |
| Average annual rainfall | 1160 mm ( world average 1110 mm) |
| Range of distribution | 150-11690 mm |
| Range Rainy days | 5-150 days, Mostly during 15 days in 100 hrs |
| Range PET | 1500-3500 mm |
| Per capita water availability (2010) | 1588 m3 |
According to the international norms, a country can be categorized as 'water stressed' when water availability is less than 1700 m3 per capita per year whereas classified as 'water scarce' if it is less than 1000 m3 per capita per year. In India, the availability of surface water in the years 1991 and 2001 were 2309m3 and 1902 m3 . However, it has been projected that per capita surface water availability is likely to be reduced to 1401 m3 and 1191 m3 by the years 2025 and 2050, respectively. The Per capita water availability in the year 2010 was 1588 m3 against 5200 m3 of the year 1951 in the country.
Table-2:India's Water Resources
| Sl.No. | Water Resource at a Glance | Quantity (km3 ) | Percentage |
| 1 | Annual precipitation (Including snowfall) | 4000 | 100 |
| 2 | Precipitation during monsoon | 3000 | 75 |
| 3 | Evaporation + Soil water | 2131 | 53.3 |
| 4 | Average annual potential flow in rivers | 1869 | 46.7 |
| 5 | Estimated utilizable water resources | 1123 | 28.1 |
| Surface water | 690 | 17.3 | |
| Replenishable groundwater | 433 | 10.8 | |
| Storage created of utilizable water | 253.381 | 22.52 | |
| Storage (under construction) of utilizable water | 50.737 | 4.5 | |
| 6 | Estimated water need in 2050 | 1450 | 129 |
| 7 | Estimated deficit | 327 | 29 |
| Interlinking can give us | 200 | 17.8 |
(Source:Water Resources at a Glance 2011 Report, CWC, New Delhi, (http://www.cwc.nic.in ))
Water Resources Management- Challenges/Issues in the Country
The major challenges/issues associated with the water resources management and development in the country are varied and complex and could be categorized as follows:
- Natural situation (Tropical Monsoon climate) – Causes large scale spatial and temporal variation in water availability, recurring droughts and frequent floods.
- Human, Managerial and Developmental challenges – These is increasing water demand and falling per capita availability, water use and energy efficiency, deterioration of water quality, reduction or deterioration of available resources (loss of surface storage), increasing competition/conflict within sectors, under and inefficient utilization of irrigation potential, over exploitation and depletion of ground water resources, water-logging and soil salinity in irrigated lands, fragmentation of management of water/ management of shared resources, lack of spatial inventory for large number of water infrastructure in the country, currently used water resources potential estimates are old, significant change in land use / land cover, demographic and utilization pattern in past few decades.
- Climate change impact –Addressing the impact of climate change on water availability and economy. Analysis of scenarios for impacts on resources and use is required to evaluate water policies.
