Three, the dependence on “distant” water to meet needs of cities, which involves high capital and energy costs. And four, the problem of exclusion. Large parts of cities remain unconnected to the sewage system as they live in “unauthorised” areas. They also get excluded from piped water supply. The good news, however, is that each of these elements also potentially enables us to design new 21st century solutions that can help leapfrog the exorbitant, unsustainable options of the mid-20th century.
The first priority for cities when planning water supply should be the restoration, protection and recharge of their traditional water-bodies. Cities must get funds for water projects only when they have accounted for the water supply from local lakes and ponds. This would reduce costs of supply from a distance, promote inclusion and preserve the ecology of the city, while also protecting regions whose water, cities are currently poaching on.
Second, the demands of inclusion and sustainability require a groundwater management plan for urban India, sensitive to the diversity of aquifers found in our towns and cities. As a first step in this direction, Himanshu Kulkarni, India’s foremost scholar of groundwater and I, have classified 150 key towns and cities into a 6x4 matrix, which captures both the stage of urban expansion (four stages) and their aquifer type (six types). We also show how the strategy to address the problem of urban water would need to be different in each of the 24 cells of this matrix.
Across this diversity, there are some common building blocks: One, identify status of existing groundwater resources through participatory mechanisms; two, demarcate natural recharge and discharge zones, quantify transmissivity and storativity of aquifers and estimate groundwater quality; three, register stakeholders, including users, tanker operators and drilling agencies and their water sources; four, build hydrogeology into waste-disposal, sewage and sullage management and design of sewerage and sewage-treatment systems; five, develop a framework of regulatory norms around urban groundwater use and protection of urban aquifers; six, understand the relationship between aquifer systems and rivers flowing through the city; and seven, develop an institutional structure required for managing the aquifers.
Perhaps, the most important lesson from urban water work is the imperative to tackle water and wastewater together. In most cities, settlements have grown without underground sewerage infrastructure. Fitting in the sewage lines into already built, crowded and haphazard construction is a difficult task. This challenge is compounded by the fact that even where sewerage lines exist, they are already buried, broken or choked. Decentralised, at times even mobile, wastewater management systems can overcome many of these problems by catering to the un-served areas, reducing cost of treatment, operation and maintenance, adopting site-specific treatment technologies based on land use and minimising land requirement.
We also need to adopt latest eco-restorative, low-cost technologies. The 2011 High Powered Expert Committee Report on Indian Urban Infrastructure and Services estimated that conventional water supply and sewerage treatment will cost the nation around Rs 5.6 trillion over the next 20 years. Apart from their prohibitive costs, these technologies are not that effective against non-point sources of pollution. They also have heavy power requirements. It has been estimated that Pune will need about 3,000 MW electricity per day to run its sewage treatment plants based on conventional energy-intensive technologies. Thus, there is an urgent need to consider alternative nature-based technology options, which have now been adequately tested on the ground. Vertical eco-filtration techniques were developed in the 1990s to treat wastewater from factories and households. These innovations helped industry to lower operational costs substantially by reducing electricity consumption, chemical and manpower requirements. Over time, the vertical eco-filtration technique was converted into horizontal eco-filtration technique or “green-bridge system”. This has now been successfully used at several locations across the country: College of Military Engineering, Pune, where wastewater was treated without electricity or chemicals in 2003; Udaipur’s Ahar River in 2010, where fisherfolk and farmers benefitted due to alleviation of pollution in the river and in the downstream Udaisagar lake; rejuvenation of the Buddha stream of the Sutlej river, which receives wastewater from Ludhiana’s urban and industrial areas and restoration of the five-stream Rasoolabad Ghat Complex of the Ganga at Allahabad in 2011.
These are the directions we must adopt in urban water policy, under the leadership of urban local bodies, whose capacities need to be urgently developed for this purpose. Such an approach will reduce dependence on distant water sources, lower financial and energy costs, promote equity, inclusion and sustainability, while also making our towns and cities much more habitable spaces.
The writer is Distinguished Professor, Shiv Nadar University and former Member, Planning Commission, Government of India