Looming water crisis can be staved off

Water is central to the sustainability of human race. Increasing and competing water demand among various sectors has led to water challenges in many regions. The last six decades witnessed a significant growth in water demand in India while per capita water availability declined from about 5177m3 in 1951 to about 1545 m3 in 2011, clearly indicating a water-stressed situation.

While demographic growth and developmental activities have increased water demand, there are supply-side issues as well-such as inefficient service delivery, wasteful water use, over-exploitation of groundwater, inadequate valuation of water, pollution of water bodies, inadequate capacities and lack of awareness. As of 2010, India had highest rates of groundwater abstraction followed by China and the US. Several regions in the country over-exploit groundwater with the National Capital Region, Haryana and Rajasthan exceeding 100 per cent.

The agriculture sector that consumes the largest amount of water has considerably low water use efficiency, largely due to the losses incurred during conveyance, on farm application and project inefficiencies. The water use efficiency of completed major/medium irrigation projects in the country is estimated at a low 38 per cent. The National Water Mission envisages enhancing water use efficiency by 20 per cent. This shall significantly improve water availability and water productivity, and reduce the demand-supply gap. Reducing irrigation water conveyance losses needs to be prioritised and use of efficient irrigation techniques needs to be popularised. Flood irrigation techniques, that involve large water consumption and losses (percolation, evaporation, drainage), need to be replaced by micro-irrigation and water-saving techniques such as drip and sprinkler system.

While the major contribution to enhancing water use efficiency has to come from the agriculture sector, some low hanging fruits lie in the urban and industrial water sector. Studies suggest that the water lost in urban water distribution is quite high and varies between 40-50 per cent. A study in 20 major cities of India shows an average water availability of 4.3 hours/day, an average 'Unaccounted For Water' of about 32 per cent and average metered connection of only 24.5 per cent. Inconsistent supply leads to wastage as the taps are kept open and water is stored in an amount larger than required.

A 2005 study by the Energy and Resources Institute in four cities of Madhya Pradesh showed that the non-revenue water in these cities ranged from 28 to 44 per cent. High levels of 'Unaccounted For Water' are indicative of inefficient water use mainly due to leakages and losses (including pilferage) in the water supply system.

To ensure long-term sustainability of water resources the focus of water management needs to shift from supply to demand side management. This calls for an integrated strategy that aims at reducing the systemic losses and exploring alternative options of recycle and reuse of treated sewage (for supply to industries, recharge of water bodies, gardening and other non-potable uses). Improving operational efficiency, promoting rationale use (incentivising water conservation), appropriate water pricing and equitable distribution is also needed.

The water requirement of Indian industries has almost doubled during the last decade and is expected to increase significantly by 2050. Various industries consume significant volumes of water and simultaneously discharge considerable amount of wastewater. Water audit of thermal power plants conducted by TERI revealed a significant scope of reducing water consumption by 18 to 26 per cent by recycling wastewater. Industries need to focus on reducing their water-footprint and regular water audits can help in this regard.

Thus while there is a significant scope of water savings in every sector, the need for efficient water management has to take centre stage in the planning processes of all sectors (agriculture, industries and domestic) with the objectives of improving water use efficiency, minimising wastage, promoting and incentivising water conservation, appropriate pricing of water, use of efficient technologies, adequate policy planning and effective implementation.