India is on the threshold of a very serious groundwater crisis, which needs mitigation both in the fields and at the policy corridors of the country. A World Bank study puts the plight of the country in perspective: 163 million Indians lack access to safe drinking water; 210 million Indians lack access to improved sanitation; 21% of communicable diseases are linked to unsafe water. Many Indian cities, including Delhi and Bangalore, face a water crisis, especially that of freshwater.

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Technologies to harness fresh water:

• Rainwater Harvesting: It is a process involving collection and storage of rain water (with the help of artificially designed system) that runs off natural or man-made catchment areas e.g. roof top, compounds, rock surface or hill slopes or artificially repaired impervious/semi-pervious land surface.
  • Pros: It reduces Runoff loss, helps meet rising demand of water by recharging the water table, No land is wasted for storage purpose and no population displacement is involved, increases the productivity of aquifer and reduces urban flooding.
  • Cons: High installation charges, lack of awareness and education,
• Desalination: It is a technology that converts salt water into freshwater using reverse osmosis (RO). Osmosis involves ‘a solvent naturally moving from an area of low concentration, through a membrane, to an area of high concentration
  • Pros: Abundance of Seawater around India. RO is commercially proven and the dominant technology. It is easier for attracting the private players.
  • Cons: RO plants convert seawater to fresh water, the major environmental challenge they pose is the deposition of brine (highly concentrated salt water) along the shores. This reduces the availability of prawn, sardine and mackerel. Environmentalists second this saying that hyper salinity along the shore affects plankton, which is the main food for several of these fish species. The construction of the RO plants required troves of groundwater. Desalinated water can also be acidic to both pipes and digestive systems.
• Low Temperature Thermal Desalination (LTTD) is one process that uses the availability of a temperature gradient between two water bodies or flows to evaporate the warmer water at low pressure and condense the resultant vapour with the colder water to obtain freshwater.
  • Pros: Better than the Desalination technique; simplicity of the LTTD process also enables to control the quality of product water in order to provide either good quality drinking water or boiler grade water as the situation warrants.
  • Cons: the LTTD technique draws power from diesel sets

The water crisis of India cannot be solved by just one type of solution. Thus, technology alone cannot be a panacea. There is a need for multi-pronged solution to tackle the crisis of water.

Other measures needed:

• India’s priority must be:
  • To make our irrigation and water systems amenable to modern concepts.
  • To complete irrigation and water sector reforms.
  • To implement improved water management, governance and regulation practices.
  • Pricing system for water: For making people use water efficiently
• Deepen our understanding of our water resources and usage and put in place interventions that make our water use efficient and sustainable.
• Augmentation of watersheds that can store more good water, for use in agriculture and to serve habitations.
• Strict pollution control enforcement.
• Decentralisation of irrigation commands, offering higher financial flows to well-performing States through a National Irrigation Management Fund.
• Groundwater extraction patterns need to be better understood through robust data collection.
• Pollution can be curbed by levying suitable costs.
• Poor maintenance of pipelines, consistent leakage and illegal tapping of water are some of the issues that need to be addressed on a war-footing.
• Adopting rainwater harvesting techniques is the need of the hour.
• A legal mandate will work better than just competition and cooperation; it would make governments accountable.
• These forward-looking changes would need revamped national and State institutions, and updated laws.
• Urban India needs to focus on recycling and harvesting water, having better testing and purification facilities and increase public awareness on the need to conserve water.
• Large catchment areas need to be developed around water bodies so that natural recharge of groundwater takes place. A good example is the Seog catchment area which has been denoted as a wildlife sanctuary and where no construction is allowed.
• Greywater recycling, a method of recycling wastewater from kitchen sinks, showers and laundry fixtures.
• Greywater recycling helps reduce household water usage by about 50% .
• This year’s World Water Development Report makes it clear that nature-based solutions which are also aligned with the principles and aims of the 2030 Agenda for Sustainable Development can offer answers to our most pressing water-related challenges.

Conclusion:

There is a need for credible environmental and cumulative impact assessments, genuine public consultation process at multiple stages of planning and project implementation, confidence-inspiring appraisal, which includes the appointment of independent experts, and most crucially, achieving some real monitoring and compliance. The water governance ought to be made transparent, accountable and participatory in every sub-sector, including management of rivers, groundwater, floods, and biodiversity, among others.

Extra information: Ancient Indians understood the art of water governance. Most of India’s traditional water management has been at the community level; relying upon diverse, imaginative and effective methods for harvesting, storing, and managing rainfall, runoff and stream flow. Some of the traditional water conservation structures:

• Phad – It is a community-managed irrigation system in the tapi river basin in Maharashtra. It starts with check dam built across a river and canals to carry water to agricultural blocks with outlets to ensure excess water is removed from the canals.
• Zing – It is found in Ladakh, are small tanks that collect melting glacier water. A network of guiding channels brings water from the glacier to the tank.
• Kuhls – They are surface water channels found in the mountainous regions of Himachal Pradesh. The channels carry glacial waters from rivers and streams into the fields.
• Zabo or Ruza System– It is practised in Nagaland. Rainwater that falls on forested hilltops is collected by channels that deposit the run-off water in pond-like structures created on the terraced hillsides.
• Jackwells – The Shompen tribe of the Great Nicobar Islands uses this system, in which bamboos are placed under trees to collect runoff water from leaves and carries it to jackwells which are pits encircled by bunds made from logs of hard wood.
• Pat system – It is developed in Madhya Pradesh, in which the water is diverted from hill streams into irrigation channels by diversion bunds. They are made across the stream by piling up stones and teak leaves and mud.
• Eri – It is tank system, widely used in Tamil Nadu which acts as flood-control systems, prevent soil erosion and wastage of runoff during periods of heavy rainfall, and also recharge the groundwater.
• Johads – They are small earthen check dams used to conserve and recharge ground water, mainly constructed in an area with naturally high elevation.
• Panam keni – The Kurumba tribe (a native tribe of Wayanad) uses wooden cylinders as a special type of well, which are made by soaking the stems of toddy palms and immersed in groundwater springs.
• Ahar Pynes – They are traditional floodwater harvesting systems indigenous to South Bihar. Ahars are reservoirs with embankments on three sides and Pynes are artificial rivulets led off from rivers to collect water in the ahars for irrigation in the dry months.
• Jhalara – Jhalaras are typically rectangular-shaped stepwells that have tiered steps on three or four sides in the city of Jodhpur.
• Bawari – Bawaris are unique stepwells that were once a part of the ancient networks of water storage in the cities of Rajasthan.
• Taanka – It is a cylindrical paved underground pit into which rainwater from rooftops, courtyards or artificially prepared catchments flows. It is indigenous to the Thar Desert region of Rajasthan.
• Khadin – Also called dhora, is a long earthen embankment that is built across the hill slopes of gravelly uplands. It is indigenous to Jaisalmer region and similar to the irrigation methods of Ur region (Present Iraq).
• Kund – It is a saucer-shaped catchment area that gently slopes towards the central circular underground well. It is found in the sandier tracts of western Rajasthan and Gujarat.