Is a combination of recycling and harvesting an answer to water crisis in Indian cities?

When some of us were in school, we were told that the next war would be fought over water. With cities like Chennai and Ranchi already facing instances of violence over water, the ‘war on water’ does not seem as hypothetical as it did a decade ago.

Almost every major city in India seems to be facing a water crisis. According to a 2015 study, three-fourths of India’s surface water was estimated to be polluted, with the largest pollutant being untreated sewage. India’s groundwater is also struggling to keep up with the need — from 2001 to 2011, the national per capita annual availability of water reduced by 15%.

The logic is simple – the demand for usable water exceeds its supply. What can be done?

As with any finite resource, two things are important – recycling and conservation. While recycling water means reducing wastage and reusing waste water with or without treatment, conservation entails harvesting, or catching and storing rainwater.

Does the answer lie in one or the other? We spoke to four water experts to find out.

Recycling 

To efficiently recycle water, we must first gauge how much water is being used, for what, and how, says S Vishwanath, a noted Bengaluru-based water expert. One way to do this is having a volumetric metering system – both at the apartment level and for sources like borewells, to measure how much groundwater is being used.

Vishwanath explains after we measure the usage, we can begin eliminating the physical and financial wastage of water. “Financial losses, i.e. theft of water without payment, should be eliminated,” he says. 

In terms of reducing physical wastage, Veena Srinisasan, a senior fellow at Ashoka Trust For Research In Ecology And The Environment (ATREE), points out that outdoor wastage of water needs to be reduced – such as frequently hosing down cars and buildings.

Image for representation; Nikhil Patil/Picxy

To the end of recycling, experts say that segregation of grey and black water is key. Grey water is one that is used for washing and comes from kitchens and baths; while black water is one that has sewerage and comes from toilets. While grey water is larger in volume is much easier to treat and reuse for non-potable purposes, black water requires more treatment.

“Once we get a handle on the water usage numbers, we must develop a network to collect all the waste water and then treat it appropriately,” Vishwanath says.   

Harvesting rainwater

While recycling is necessary, water can be managed best in our cities if it is complemented by rainwater harvesting. Incidentally, harvesting can also take some load off of recycling and treatment. This is explained by Leo Saldanha, founder of Bengaluru-based non-profit Environment Support Group, who asserts that harvesting rainwater should be non-negotiable. “It is an unintelligent idea to wait for water to be contaminated, put it through secondary and tertiary treatment, and then feed to cities the scale of Bengaluru. All the money the city earns in revenue will go to clean the water,” he argues.

Harvesting is also important to recharge groundwater and reduce dependence on external sources such as tankers and borewells. Giving the example of Namma Metro in Bengaluru, Leo says that instead of letting out the rainwater that’s collected on the tracks in the corridor onto the roads below, the pipes could have been connected to recharge wells or storage tanks. “It’s a criminal wastage of water. Moreover, it causes flooding and stagnation on the roads below,” he argues.

Experts say that setting up a rainwater harvesting system has become simpler in recent times and is quite inexpensive, given its returns. Leo insists that any residential building or house can set up a system on their roof. He says that commercial establishments must do it because they have the resources to. The components of rainwater harvesting - such as the catchment to collect rainwater, filtration system, and sump - are explained here.

To address our water crisis, experts say recycling and harvesting must go together. Veena quotes Vishwanath to say that there are four sources, or ‘taps’ of water– water sourced from afar; water that is in the catchment areas in the city (stormwater); waste water (treated and recycled), and groundwater. While ‘water from afar’ essentially refers to water piped from rivers and/or rural areas, the second source are the lakes and water bodies that maintain water in the city.   

In cities, the assumption is that water comes largely from afar. However, the focus must shift to sourcing most of the water from the catchments within the city limits, which cannot happen unless recycling and harvesting are taken up in a big way. “You cannot focus on one without the other (taps),” Veena says.

Image for representation; Raja Stills/Picxy

Giving the example of the Chennai water crisis, Vishwanath explains that it is happening because a majority of the city’s water supply is self-provisioned through groundwater and water tankers. Groundwater is being depleted as a much faster rate and dependence on tankers places too much stress on water sourced from afar and creates opportunity for financial exploitation of residents in a water scarce year, such as this one. 

“The Chennai Metro Water Supply and Sewerage Board is a minority player in water supply, and therefore struggles to control a situation such as this because it virtually has no influence,” Vishwanath argues.

Further, with waste water not being recycled, it ends up mixing with the sewerage and pollutes water bodies such as lakes and ponds, due to which they are no longer able to serve their purpose of rainwater harvesting. This, in turn, contaminates groundwater as well. “If you’re polluting all sources of water, everything is rendered unusable,” Veena says.

What our cities lack

When it comes to recycling waste water, it needs to begin at the apartment level with the segregation of grey water and black water. This can be achieved by separating their plumbing. However, in most cases, this is not done.

Priyanka Jamwal, a water expert and fellow at ATREE, says, “The problem right now is that both are being mixed, which makes reuse and recycling harder, because black water is more difficult and energy intensive to treat,” she tells TNM. “And even when it is treated, it has a colour and odour because of excreta that was in it. People are hesitant to use this water.”

The problem is compounded by improper drainage. In Bengaluru for instance, because the drainage of a large number of independent houses and new apartments is going incorrectly through Bruhat Bengaluru Mahanagara Palike (BBMP) pipes, which are improperly connected to the Bengaluru Water Supply and Sewerage Board (BWSSB) pipes, grey and black water mix, points out Leo. The BBMP is responsible for storm water drains and the BWSSB for sewerage lines. As a result, the wastewater also contaminates rainwater, further polluting the lakes.

Bengaluru's Bellandur lake, one of the most polluted water bodies in the city

One of the biggest issues is also untreated sewage being let into water bodies. According to Central Pollution Control Board data from 2009, class-I cities and class-II towns generate approximately 38254.82 million litres of sewage per day (MLD). However, only 11787.38 MLD (31%) is treated. The rest is drained into water bodies as it is. These numbers seem to not have changed years later in 2015 as well - 70% of India’s sewage was still estimated to be untreated then. 

This hinders natural rainwater harvesting systems as well. Veena points out that beyond the apartment level and some commercial and corporate buildings, harvesting is not taking place because water bodies in cities are too polluted to serve as rainwater harvesting catchments. As the cycle goes, it again means that this water is either rendered unusable, or has to go through a lot of energy-intensive purification to be used.

Leo states that open wells and recharge wells also need attention. Recharge wells, as the name suggests, recharge groundwater by allowing the water that collects in them into the ground. This in turn replenishes the shallow acquifiers - water bearing formations that are located 10-100 feet underground. In urban settings, recharge wells become especially important because the concretisation makes it difficult for the water to seep down to the ground on its own. More details about recharge wells, how they work, and how they can be built here.

“Anywhere there is an opportunity that we can store water as it is, without contamination, it must be done,” Leo reiterates.

What can be done

Capacity building

Experts say one of the biggest hurdles in managing water is that the institutions responsible for it do not have people who have expertise in water management, nor adequate resources.

Vishwanath points out that “in the case of Bengaluru, BWSSB does not have any hydrogeologist, so it’s blind to groundwater. It does not have any hydrologist, so it is blind to lake water. Unless institutions are first capacitated and develop the eyes to see, we can’t manage water efficiently. Individual responsibility can only take us so far.”

Workable masterplans

He adds that our cities should have a dynamic and workable masterplan where water planning must find prominence. Further, institutions entrusted with water management need better funding.

Among other suggestions, Leo suggests de-concretising storm water drains, and instead planning bushes and plants that are water tolerant there. “Not only will it create jobs, but it will ensure that the rainwater is somewhat filtered due to flora before entering the lakes, but also foster a biodiversity and ecosystem of its own,” he says. 

Better preparedness

Veena, on the other hand, suggests that there should be better preparedness. To prepare for drought years, she suggests adopting the system of water markets, which is already in place in several countries such as Spain, the US, Chile and most notably, Australia.

In Australia for instance, markets are the process by which value is assigned to water, and hence, incentivises water moving to higher value areas. Water is traded within local catchments, and where possible, between catchments, and along river systems, beyond the regular water sharing arrangements when needed. 

This need usually arises during the time there a water scarcity, like a drought year. At such time, water is bought from another place to a place where it has more value. For example, a vegetable growing farmer will not face as much loss as a person who has an almond orchard. The latter’s orchards - that take years to grow - will die without water, while the farmer growing vegetables can simply return to sowing when the water scarcity ends. This farmer can be compensated for giving up water to the orchards. 

When water is traded this way, it also creates incentive to reduce wastage. Veena says that this system can be tweaked and adopted in India as well. “Say, every year, a part of the budget is put into a drought fund. In a drought year, this extra money can be used by the government to buy water from another place. Farmers growing water-intensive crops like rice and cotton can be compensated during a dry year for letting their lands go fallow. The water that would otherwise be used for irrigation could then be diverted to a city,” Veena explains. 

However, water markets can be politically contentious, and could potentially lead villages to compete with cities’ requirements, by compelling them to give up irrigation water. 

Incentivise reuse

Veena adds that governments can also consider incentivising treating wastewater for reuse for government agencies. “We pay for water services, but if a BWSSB in Bengaluru was also getting paid to treat wastewater for reuse, it would encourage them. Yes, it would take more out of people’s pockets, but there could be a provision to enable apartment residents to claim rebate on this amount if their buildings have filtration and purification systems in place to treat waste water in their own capacity. Aligning incentives in such a way would encourage reuse and recycling at a policy level.”

What you can do as an individual

As an individual, experts say that there are ways for you to participate. You could demand a rainwater harvesting system to be set up in your apartment complex, and install one in your own house. Complement this by installing a filtration system that can take care of treating and reusing grey water. 

Judicious use of water is also advised - low intensity taps at home, avoiding watering plants when there’s a rain forecast, and plugging leaks immediately are some ways to do this.

People can also participate in the public process by building pressure on public institutions and participating in initiatives like lake clean ups and rejuvenations.