Managing India’s freshwater4 min read . Updated: 12 May 2016, 01:41 AM IST
Where private property sits on a deep aquifer, the owner drains beyond his boundaries. This needs to change
While India has adequate freshwater, its spatial and temporal distribution is very skewed, and usage inefficient and wasteful. The current drought in several parts of the country raises questions regarding how the management of the country’s water resources could be improved by reducing its dependence on the monsoon.
The ministry of water resources has estimated that with 2.5% of global landmass, India has 4% of the world’s freshwater resources. This has however come under increasing demographic stress since India is home to about 16% of world population and the distribution of freshwater is skewed spatially and temporally.
The Central Water Commission estimated that the Ganga-Brahmaputra-Meghna basin with 33% of the landmass had 60% of total water flows. The western coastline with 3% of the area had another 11%. This left just 29% of water resources in the remaining 64% of the area in peninsular India where drought is common and farmer suicides routine. The controversial river-linking scheme to transfer water from surplus to deficit basins was mooted to address this spatial imbalance.
Most rainfall is received over a relatively short duration during the monsoon. This leads to temporary flooding. Huge amounts of surface water quickly drain into the sea. The pace of this run-off can be reduced through inter-basin transfers, new storage reservoirs, desilting, reviving traditional water storage structures such as ponds, dissemination of groundwater recharge technologies, and water harvesting structures such as check dams, open draw wells and rooftop devices.
Surface water resources are renewed year after year through the hydrological cycle. The phreatic water table, tapped by open draw wells, is likewise automatically fully recharged. The Indo-Gangetic plain is one of the biggest groundwater reservoirs in the world as it is a natural freshwater sink. The country’s freshwater resources are however used inefficiently. The biggest culprit is agriculture that accounts for 80% of all freshwater usage. Flood irrigation, prevalent in more than 95% of the irrigated area, damages both ecology and farm economics. Farmers at the tail end of major command systems receive delayed and deficient supplies, while those upstream use the grossly underpriced water wastefully. A time-bound plan to bring the entire cropped area under controlled irrigation (sprinklers, underground pipes and other water conservation devices) should be undertaken.
Unsustainable drawal of freshwater mostly occurs when water trapped in underground rock formations below the phreatic water table in deep aquifers over centuries, millennia or even millions of years, is extracted at levels exceeding the natural rate of recharge. While surface water and the phreatic water table have always been utilized for consumption, humans have only recently developed the technology to tap deep aquifers. This can completely empty them within a relatively short period of time.
Groundwater depletion in urban areas is largely due to poor piped drinking water supply. In rural areas, regions away from river systems, or disadvantaged by the scarce availability of surface water bodies, are constrained to fall back on groundwater for agricultural expansion, as in large parts of western, central and peninsular India. These are mostly areas of dry land cultivation, where agricultural productivity has expanded in recent times through massive, unsustainable exploitation of deep aquifers.
The drilling rig and electric pump revolution has permanently depleted groundwater reserves in several areas, with water and power subsidies compounding the problem through inefficient use of a scarce resource. Excessive drawal has also led to increasing concentration of toxic elements such as fluoride, arsenic and salinity in several areas.
Modern science and technology can be leveraged to artificially increase the rate of recharge of aquifers, thereby enhancing the sustainable exploitation of deep aquifers. It is imperative to have a good database updated in real time on the size and sustainable levels of exploitation of our freshwater resources. The beginning made through the National Hydrology Project needs to be extended and made more comprehensive, including through mapping of deep aquifers in the country and determining rates of recharge.
Once this is done, extraction rates would need to be capped, calibrated to recharge. In view of sharply falling groundwater levels, several states have put, or are considering, legislation to regulate the use of groundwater. Such efforts have however met with limited success as it has been impossible to monitor the large numbers of tube wells that have proliferated all over the country. What is perhaps required is a major legislative change which puts water on par with other natural resources. Minerals sitting under private property belong to the state, which has the right to regulate and licence their extraction. But subsurface water resources belong to the property owner. Where private property sits on a deep aquifer, the owner is within his rights to drain the entire aquifer that may extend far beyond the boundaries of his property. This needs to change. Landowners should be free to tap the annually rechargeable phreatic water table through open wells on their property, but deep aquifers need to be treated as a common resource.
Policy coordination is essential to improve the management of the country’s scarce water resources. In the US, all water issues are handled by the department of agriculture, the major source of demand. In India, water falls between several stools. Agriculture, the biggest bulk user, is outside the purview of the ministry of water resources that frames the national water policy. Drinking water falls within the domains of the ministries of rural development, urban development and Panchayat Raj. This departmental fragmentation of water management needs to change, both in the centre and the states.
Alok Sheel is a civil servant. These are his personal views.
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