In 2018, Cape Town’s water crisis captured the imagination of the world. As the Indian monsoon lags, people are waiting anxiously for the rains. The question is, how bad will it get in cities in South India and what can we do about it? As with all things water, there are no simple answers.
Of the southern cities, Chennai is the most vulnerable to both droughts and floods. The city is largely dependent on a set of small reservoirs that are exclusively for its use. The storage is not enough to tide the city over two consecutive dry years and the rapidly urbanizing state has not been able to expand reservoir capacity. As a result, despite the devastating floods of 2015, the reservoirs are completely dry; the city is in the throes of a severe crisis. Supply from Chennai’s desalination plants and a pipe from Veeranam lake in the Cauvery delta barely meet a quarter of its demand. Over the summer, piped supply virtually shut down.
Cities like Bengaluru, Coimbatore and Hyderabad are a little more immune to complete shutdown, because they are served by large multi-purpose reservoirs. Since urban supply has higher priority than irrigation, even if the reservoir levels drop, it is the farmers, not the cities, that bear the brunt. For these cities, the problem is unprecedented urban growth that makes it impossible to keep pace; the drought mainly affects newly developing areas that lack piped mains. Because these areas also lack sewage infrastructure, they face the double jeopardy of contamination from unlined soak-pits/open drains and borewells running dry.
For many in South India, Cape town’s dreaded “zero-day” (no piped supply), is in fact every day. Perhaps, crisis fatigue is why the issue has not attracted international headlines as Cape Town did.
The traditional solution proposed has been to call for interlinking of rivers, moving water from water surplus states in the North to water deficit states in the South. But setting aside pumping costs and environmental impacts, in India’s federal system, inter-linking is unlikely to work because the real constraint is a lack of storage, not volume available for transfer. Project feasibility studies, framed in terms of a 50% dependable yield in million cubic metres of water per year, mask this problem. The reality is that states have historically been unable to control the timing of releases from reservoirs located outside their borders. Chennai’s Telugu Ganga project is an example. Often, the water is released from Andhra Pradesh in precisely the months when Tamil Nadu’s own reservoirs are full. Urbanized states like Tamil Nadu do not have much land to allocate to new dams and have therefore been unable to take full advantage of inter-state transfers.
If traditional engineering, large-infrastructure solutions are challenging, the only alternative for some cities is to use local water more wisely. Cities across the world are envisioning a “pipe-less” future by harvesting rainwater and storing it below ground (in sumps or the aquifer), using water efficiently, and recycling wastewater with full nutrient recovery. Simulation models show that cities could greatly reduce their dependency on imported water by adopting these measures. And, in fact, components of this approach are already in place; most South Indian cities already mandate wastewater recycling and rainwater harvesting for apartment buildings.
If we know what to do and have already taken the first steps, why is it so hard to fulfill the whole vision? One problem is that the decentralized components are viewed as temporary fixes by our water utilities, who dream of centralized piped water and sewerage, even though many developed cities are moving in the opposite direction. The second problem is that governance is fragmented and the dots are never connected.
There are, however, some low-hanging fruit in the short term. First, better implementation of rainwater harvesting in public and private lands must continue, as the urban areas are paved over and natural recharge of groundwater is reduced. The million wells and lake rejuvenation projects in Bengaluru are good examples of public efforts. Second, invest in sanitation engineering capacity and encouraging sale of treated wastewater to parks and construction sites could quickly boost wastewater reuse. Many apartment-level wastewater treatment plants fail because they cannot find well-trained engineers. Retrofitting buildings to reduce water use, both indoors (plumbing) and outdoors (landscaping), is similarly constrained. Investment in skill development through sanitation engineering, green plumbing, and low-water use landscaping diploma courses could allow consumers and the private sector to do better.
In the medium to long term, however, institutions that can connect the dots between stormwater, groundwater, sewage and piped water have to be built. Currently, water supply and sewerage are managed by urban water utilities, storm water by the urban local bodies, and groundwater is not managed at all! Even a cursory reading of plans and manuals by different agencies will reveal they are not internally consistent. For instance, the recent stormwater design manual recently released by the CPEEHO (the standards agency) only cursorily addresses the fact that most Indian drains and lakes are full of sewage year-round, greatly reducing their stormwater carrying capacity. In one southern city, it was clear that restoration plans for urban streams could not be effective if the city’s own sewage plan were to be implemented. To avoid working at cross-purposes, an Integrated Urban Water and Wastewater Management plan with consistent assumptions about infrastructure is a necessary first step.
Realigning utility incentives could offer a policy fix in the medium term. Most water utilities charge monthly bills only for water supply, not sewage. Consequently, water utilities have an incentive to postpone laying sewerage mains. In fact, for some Indian water utilities, as much as 90% of the spending goes to water and only 10% to sewage collection and treatment. If the water utility was able to charge for sewage (75% of water bill), it would have an incentive to allow sewerage and treatment services to keep pace. Allowing consumers, who treat and reuse wastewater to claim a waiver, would encourage decentralized wastewater treatment.
Indian cities deserve robust world-class urban water systems that are sustainable and equitable, but it does not follow that centralized piped-infrastructure must be the sole solution. We need a diversity of solutions that work in tandem. This requires political will, change in engineers’ mindset and skills, consumer awareness and money; but most importantly, we need institutions and processes that will ensure that the dots get connected.
(The writer is Senior Fellow, Ashoka Trust for Research in Ecology and the Environment, Bengaluru)