Let’s begin with some statistics. The total average precipitation availability in India has remained broadly constant at around 3,880 billion cubic metres. Meanwhile, the average water flow in our river basins, as assessed by the Central Water Commission, stands at 1913.60 Billion Cubic Metres. Nevertheless, increasing population has reduced per capita availability to around 1,431 cubic metres per person, below the 1,700 cubic metres per person ‘water stress’ defined by Malin Falkenmark.
So then, where can technological interpretations help?
Remote sensing, hydrological flow measurement and rainfall data has helped the CWC to come out with an excellent report assessing the water flows. In future, it should be dynamically modelled at a river basin and sub-basin level to help manage water for ecological, social and economic purpose. Dynamic flow modelling and tracking of rivers will also help in reservoir management and flood management.
Agriculture remains the single largest consumer of water. Canal irrigation systems suffer from lack of efficiency, with tail end canals bearing the brunt of water shortage. Significant improvements will be needed in order to shift to pipe-based network distribution systems controlled by SCADA for increasing the irrigation efficiency of our dams.
Precision technologies such as drip irrigation, micro-sprinklers and poly-houses not only help in soil management, crop development and management, but such technological innovations have the largest capacity to save water. Products that are affordable and efficient are still needed. Low cost soil sensors to assist farmers in irrigation schedules, efficient pond lining material for farm ponds, and drips that require less cleaning should see progress.
Groundwater is India’s lifeline, with more than 22 million wells and borewells and over 250 BCM of groundwater being extracted annually. The advent of the hard rock drilling rigs in the 1960's and 1970's unleashed the groundwater revolution. Many have ascribed the success of the green revolution in terms of high yield of wheat and rice to the tube-wells and motors that supplied the water for the HYV varieties. The ability of technology to dig deeper has meant that borewells now draw fossil water from as much as 500 metres below the earth. This has exhausted groundwater in many parts of India.
Technology can not only help identify and map aquifers and sub-aquifers but also develop a sustainable way of replenishing and reusing of rainwater and groundwater.
In urban areas, technological innovation like easy to measure water meters will need to become the norm for every flat and building in the city. Leak detection equipment to identify and plug leaks, which are easy to use and accurate, will become necessary where 50 per cent of the water or more are lost during the distribution process. Plugging water leaks will bring enormous benefits to the system. SCADA systems, which can manage water systems and pressure optimisation for 24/7 water supply in our cities, will call for technological interventions.
Small scale wastewater treatment plants that can recycle water to drinking water quality to large scale ones that also recover energy and nutrients will need to be developed. Chennai already has four such plants.
Faecal sludge management will need special focus. Transport and treatment of this sludge will become important for sanitation management across India.
Desalination plants will come up in more numbers in coastal cities but they need to be adapted to the local conditions.
All technological interventions need a strong policy and regulatory framework.
Policies like metering in flats or wastewater treatment plants for residential apartments will give innovators, start-ups and existing players a market to develop and refine their ideas.
Nevertheless, the water crisis cannot just be looked at from a technological perspective. There is also a need to incorporate institutional, financial and ecological perspectives. Thus, a holistic approach aided by technology can pay rich dividends.
(The author is a noted expert on water issues. He is popular on Twiiter as @zenrainman)...