‘Bengaluru can become worse than Cape Town if mismanagement of water continues’: TV Ramachandra

Ramachandra also explains why the water crisis can get worse than South Africa’s Cape Town and how the Bengaluru Water Supply and Sewerage Board (BWSSB)’s actions have only proved to be a disaster in managing water. Excerpts:

How do you read the water crisis that has gripped Bengaluru city?

Bengaluru has a severe water scarcity today. Forty per cent of Bengaluru’s water requirements come from groundwater resources and 60 per cent come from the Cauvery. The Cauvery basin, because of deforestation over a period of time and changes in climate, has lost the ability to retain water, which is further compounded by erratic rainfall.

In the last five decades, the Cauvery basin has lost 45 per cent of forest cover, and today we have only about 18 per cent of forest cover in the region. Our study shows that wherever forests are there in the watershed area, the water is available throughout the year. However, with very low retention of water in the catchment area and because of deforestation, all the water is rushing towards the ocean, causing a scarcity in the Cauvery basin this year.

What led to the depletion of groundwater in Bengaluru?

The groundwater is available underground only when you allow the recharging to happen. The groundwater recharging happens only when the landscape is porous. The landscape is porous when you have the vegetation cover and the water bodies. However, the landscape in Bengaluru has changed drastically over the years. In the 1800s, Bengaluru had 1,452 water bodies and 80 per cent green cover. Today, we have about 193 water bodies and less than 4 per cent green cover.

Dr T V Ramachandra, Coordinator, Energy and Wetlands Research Group, Indian Institute of Science, Bengaluru.

If you look at the last five decades, in 1973 the Bengaluru landscape had 68 per cent green cover and less than 8 per cent of paved surface. For any city to be liveable you need adequate oxygen and water. There is oxygen deficiency in the region (Bengaluru) because of lesser tree cover in the region. As per a study, Bengaluru has one tree for seven to eight persons, whereas scientifically we should have seven to eight trees for one person. As a result, we did not allow the water to percolate in Bengaluru.

Bengaluru’s water crisis is being compared to the Cape Town-like situation. How far is this true?

Yes. I agree. News reports had revealed that Cape Town was on top of water scarcity because of mismanagement. If the current situation of mismanagement (of water) in Bengaluru continues, we are going to pay a heavy price with a situation worse than Cape Town. Whereas Cape Town has recovered, in our bureaucratic system we take advantage of scarcity and we give the city to the water and land mafias. They become more powerful, as is happening today.

I strongly suggest the government listen to these warnings seriously. A 1055 per cent increase in concrete area, loss of 88 per cent of vegetation, and 79 per cent of water bodies in the city, oxygen deficiency, and water scarcity have moved Bengaluru to unlivable status. For any city to be liveable we need to plan for the city below the threshold of carrying capacity. But Bengaluru has crossed the threshold. For us to achieve the threshold of carrying capacity, we need to decongest the city. We need to move industries to other cities and taluks in line with a cluster-based development model so that there is no migration to Bengaluru in search of jobs and livelihood.

How can Bengaluru come out of this water crisis? What are the solutions?

We need to make everyone environmentally responsible. Environmental literacy is very important. If they become environmentally sensible, people will manage water bodies, park in the neighbourhood, will refrain from polluting water bodies etc. Otherwise, people and those in power will only resort to water mismanagement. As for the water availability in the region, with 700-850 mm of annual rainfall, we have about 15 TMC of water in the city. The city requires about 18 TMC of water. That means 75 per cent of the water required for Bengaluru is available in the form of rainwater. The best option is to adopt rainwater harvesting either through rooftop harvesting at houses or by rejuvenating the lake and retaining the rainwater at the community level. This will ensure a good amount of groundwater recharge.

In fact, the rejuvenation of Sarakki Lake and Puttenahalli Lake has proven to be useful during this water crisis.

Yes, Sarakki Lake was rejuvenated three years ago. Within a year the ground water level went up by 320 feet. Today, the lake has enough water and the surrounding wells also have a good groundwater table. Because of the good moisture content in the region, the temperature is also two to three degrees lower. This shows that we have to rejuvenate the lakes and desilt the lakes. In fact, the silt can be used as a substitute for fertilisers by farmers, which will increase the crop yield.

Lake rejuvenation will ensure 15 TMC of water for Bengaluru. On the other hand, Bengaluru generates 18 TMC of wastewater. If we treat this water at the tertiary level, we will generate 16 TMC of treated water. You have to treat the water to the tertiary level because secondary treatment plants will only remove the chemical ions while tertiary treatment will remove the nutrients.

In fact, the contamination of water is because of the nutrients. The water rejuvenation and management model at lakes like Puttenahalli, Sarakki, and Jakkur must be replicated across Bengaluru on priority. Taking the lessons from the current crisis, if we can intervene and manage our lakes and the green cover, we are solving the water problem of the city for the long term.

What do you make of BWSSB’s measures such as a ban on potable water for construction activities, vehicle washing, and taking over water tankers in the city among other actions?

The BWSSB’s approach is a reactionary and an ad-hoc approach. They lack the required competency to face the situation that is because we have not put the right people in the place. This is a serious anomaly in the system. Why are organisations like BWSSB headed by IAS officers? Why can’t we have subject experts? We need to have officials from the Indian Engineering Service (IES).

Moreover, the assurance by BWSSB to supply 2600 MLD of Cauvery water to Bengaluru for the next two months is baseless. When lakes are being rejuvenated BWSSB comes up with a proposal to fill the lakes with partially treated water. They have no right to do this. This will scuttle the rejuvenation process and at the same time, they are polluting the lake.

Further, the water tanker or real estate mafia reflects the pathetic status of a region and the failure of the executive mechanism. They have failed miserably, which is why people opted for water tankers but unfortunately, they are being harassed and abused by the mafia. I would suggest the government make bureaucracy accountable, audit the resources available, and ration the water equally to all sections of the society throughout the city. Second, for non-potable purposes, they should provide treated water using tankers and supply it to the city. The government should have control over it rather than giving it to the mafia.

How can we use technology such as Artificial Intelligence and Machine Learning to manage water?

The remote sensing data analysis of water through AI can help in many ways. Deploying labour to collect and analyse to check water quality is a challenging task. Instead, deploy sensors which will collect data and alert whether water is contaminated or not. In fact, AI can also detect pilferages of water. When you install AI sensors at apartment buildings, you can detect which house is wasting more water.