4S is a collaboration of several Indian and foreign partners who all contribute their specific know-how and experience. My role has been to coordinate everyone’s involvement and to guide the different study components. The actual field work in Karnataka, Tamil Nadu and several other states was done by our local data collection teams.

Bangalore has a population larger than that of Switzerland, and it continues to grow. This density and dynamic makes it a tremendous task to provide sufficient water to the city. Besides the supply aspect of the water crisis, however, we should also understand the related health, environmental and even traffic problems that come along, among others. Most water ends up as wastewater at some point, which – if not treated – can become a cause of diseases, pollution of water resources as well as environmental degradation. Bangalore’s current wastewater infrastructure allows to treat less than half of the wastewater generated every day. About 48% of the drinking water supplied by the city utility networks is lost as non-revenue water (through leakages, illegal connections, etc.). This economic loss reduces the utility’s ability to invest in much needed infrastructure improvements. In addition, water tariffs are too low, which doesn’t incentivise water-saving. As a consequence, more and more energy-intensive water imports from far away have been required, thousands of water supply trucks add to traffic congestion, and hundreds of thousands of private wells pump up increasingly polluted groundwater. No one knows how much, but what is understood is that the water table is receding due to overdraft.

You see, this is a complex, multi-dimensional problem with many social, economic, technical and management aspects. The search for sustainable solutions has to integrate all of these aspects.

The good news is that Bangalore does not necessarily have to be in a water crisis. A recent study shows that there is actually enough water even for 20 million Bangaloreans, if wisely managed. Management is the key, and that essentially involves five steps: capture, recharge, reduce, treat and reuse. Bangalore receives fairly good amounts of rain (although spread over 5 months only). If harvested (in tanks and by recharging groundwater), this source could become the main primary source of water supply for the city. But Bangaloreans will also have to reduce their water consumption. This is easy with waterless urinals, low-flush toilets, and water-saving nozzles, showerheads and washing machines. Everyone can install such gadgets at home and at the workplace to become part of the solution, without even compromising comfort. And everyone can help minimise the use of chemical products to reduce water contamination and treatment requirements. But many people are not sufficiently aware of the challenges and their possible solutions. Awareness raising and behaviour change communication are therefore needed – starting at the schools.

As part of the 4S project we are looking at another key piece of the puzzle: water treatment and reuse. Treated used water can be recycled an indefinite number of times and thereby make the available resources almost limitless. Karnataka has long recognised this potential, and made it mandatory for new, big construction projects to install their own small-scale sewage treatment plants (STPs) with dual piping for reuse. These STPs, of which there are now thousands in Bangalore, provide water that can be reused for toilet flushing, gardening and other purposes. At the same time, they address pollution of water bodies. However, it has become a challenge to ensure the optimal design, operation and performance of all these thousands of distributed units. Many don’t work well, others impose a heavy financial burden on their owners. Through the 4S project we aim to better understand the problems on the ground. Our goal is to provide recommendations on how to improve and best manage small-scale sanitation systems so they can fulfil their role for healthy and water-secure South Asian cities.

All the available solutions and best practices have to be showcased and promoted. During my stay in Bangalore I was lucky enough to live in an extraordinary, self-contained eco-house in Nagarbhavi, where we collect rainwater, use water-saving appliances, as well as segregate, treat and recycle different streams of used water according to their level of pollution. Such demonstration projects help to show that a sustainable water future is possible with solutions existing today. And more solutions are being developed around the world. We, therefore, need to foster inter- and transdisciplinary collaboration as well as information exchange across boundaries.

In Switzerland, we are blessed with sufficient year-round precipitation and little water scarcity challenges. Despite the differences of the context, Switzerland has a broad and internationally relevant water expertise to offer, ranging from water and wastewater treatment technology to dams and hydropower, flood protection, ecosystems management, transboundary water management, sustainable water governance, water education and more.

Many Swiss organisations work on solutions that are specifically relevant for solving global water issues (for more information, visit www.swisswaterpartnership.ch). At Eawag, for instance, my colleagues are developing a self-sustaining grid-free (autark) toilet. Through the separation of urine, faeces and water at the source, the three streams can be treated according to their specific properties, which allows a maximum recovery of resources, such as nutrients or water (for further information, visit www.autarky.ch). In the future, solutions like these could very well find their application in Bangalore.

(The opinions expressed in this article belong solely to the researcher.)