As summer intensifies, Bengalureans are once again worried about their taps running dry and the possibility of steep hikes in tanker water prices. Water shortage could be critical this summer in 80 wards, according to a study released by the Bengaluru Water Supply and Sewerage Board (BWSSB) last month.
The study, resulting from a collaboration between BWSSB and the Indian Institute of Science (IISc), predicted a sharp decline in the groundwater levels of these wards by April. These wards, mostly located in the city’s peripheries, are dependent on groundwater.
In a press release, BWSSB chairperson Dr Ram Prasath Manohar said the study is a milestone in their efforts towards sustainable water management. He exhorted citizens to use less groundwater and to adopt Cauvery Stage V water connections. But experts slam the study, saying it offers nothing new and no clear, actionable measures.
Following the study, the government has announced mandating Cauvery connections for all apartments, yet it has not addressed complaints about low water supply from apartment residents who already have connections.
Eighty wards at risk of ‘severe water scarcity’
The study has identified 80 wards where water shortage could be critical this summer. Many of these wards are located in the erstwhile 110 villages. Here, the groundwater levels are projected to drop by 20-25 metres in April compared to the levels in December. Water stress will be highest in Southeast Bengaluru and Whitefield, the study notes.
In the erstwhile City Municipal Council (CMC) areas, groundwater levels are expected to drop by 10-15 metres, and in the core city areas by 5 metres.
The projections are based on geospatial mapping, data analysis and field surveys. Continued water extraction will exacerbate shortages in the 80 critical wards, the study says. The map below, by OpenCity, shows wards that are likely to face water scarcity this year. Click on the shaded regions for ward details.
However, the study does not go into the reasons for these wards’ water scarcity.
The total demand for freshwater in the city is approximately 2,632 Million Litres per Day (MLD). But BWSSB’s Cauvery connection (stage I to stage IV) meets only about three-fifths of this requirement — approximately 1460 MLD. As a result, Bengaluru extracts 800 MLD of groundwater, as the BWSSB study notes.
Though the Cauvery stage V project is expected to provide an additional 775 MLD of water to the city, the project has lagged by years.
The city’s current groundwater extraction of 800 MLD is significantly greater than the amount of groundwater being recharged. The natural recharge is as low as 148 MLD. Recharge through other sources such as pipeline leaks and wastewater drains is higher at 455 MLD, but this is just an estimate. The higher extraction above recharge means the city’s water reserves deep underground are being rapidly depleted.
The BWSSB study states it has identified areas with high recharge potential through detailed data analysis, and that these areas can play a critical role in groundwater replenishment if properly managed. But it provides no information regarding these high-potential areas.
To understand more, we reached out to one of the authors of the study at IISc, who declined to comment citing an agreement with BWSSB.
Read more: What data says about Bengaluru’s alternatives to Cauvery water
Apartment residents oppose compulsory Cauvery connections
To reduce groundwater extraction, the study recommends increasing Cauvery connections in the critical wards, monitoring groundwater levels, and recharging lakes with treated wastewater. It also mentions involving local communities in participatory groundwater management, but doesn’t elaborate on what this would entail.
While these measures are already limited in scope, the BWSSB’s press release mentioned only Cauvery connections as the solution. “We urge residents, especially those in high-risk wards, to reduce their dependence on groundwater and switch to Cauvery water connections. The Cauvery Phase 5 Project has increased water availability, offering a sustainable solution for Bengaluru’s growing needs,” the press release said.
Recommendations in the study
- Establish Cauvery water supply stations in critical wards. Each station should serve a 5-km radius
- Fill lakes in critical areas with treated wastewater, and regularly monitor lake water quality to ensure effective recharge
- Sensitise apartments to reduce borewell dependency and enforce stricter monitoring of high-extraction zones
- Regularly monitor groundwater levels in critical wards
- Involve local communities in participatory groundwater management
Recommendations in BWSSB’s press release
- Residents in high-risk wards should reduce groundwater dependence and switch to Cauvery water connections
Following the study, Deputy Chief Minister D K Shivakumar announced that Cauvery connections would be made mandatory for all apartments in Bengaluru. But citizens do not find it feasible.
“There are 197 flats in our apartment and we have to pay around Rs 2 crore and some bribe to get Cauvery connection — from which we will get water once in a week. This won’t be enough, and we still have to get water from water tankers, which will cost us extra. We will end up paying for water tankers, and also huge amounts for Cauvery connection,” says Freesto Francis, resident of DSR Eden Greens apartment, Carmelaram.
Cauvery water could be sufficient for individual and row houses, but not for apartments, he added. Freesto expects the government to ensure that at least 70-80% of their daily water needs will be met through the Cauvery water connection, which is currently not the case.
While the city’s lake, water and sewerage systems need a lot of development, mandating costly Cauvery connections that don’t fulfil consumers’ water needs is ridiculous, experts say. “There are many people who paid money to BWSSB and are still waiting for Cauvery connection and for water to flow in their pipes, and that has not happened yet,” says Vishwanath Srikantaiah, water conservation expert.
Responding to Citizen Matters, a senior official from BWSSB, who doesn’t want to be named, says the city can’t depend on groundwater for long, and that reducing groundwater extraction as much as possible is the government’s main intention. The official also argues that the infrastructure to get Cauvery water has cost the Board more than Rs 5000 crore, and hence people have to pay for it. “People should implement rainwater harvesting, and avoid using water for car wash and avoid groundwater extraction. According to me, we can supply 100% water needs from the Cauvery connection now that stage V has been inaugurated.” If not 100%, the Board will be able to meet at least 70% of a household’s needs, and people can meet the rest of their water demand using groundwater, he adds.
Loss of water recharge and reuse potential
Every time Freesto takes a morning walk around Mullur lake, he notices untreated wastewater being released into the lake from the recently built paying guest accommodations nearby.
Even the rejuvenation of lakes often doesn’t help as sewage treatment systems are inadequate.
Bengaluru generates 1940 MLD of sewage, of which a quarter is untreated, according to the Bengaluru Urban Water Balance Report, published by the research organisation WELL Labs in 2023. The untreated sewage is often let into lakes. Though three-quarters of the sewage does get treated, only 30% of the total wastewater is eventually reused, the report said. This means, there is huge potential to scale up the city’s wastewater treatment infrastructure.
According to an affidavit filed before the National Green Tribunal by the Central Pollution Control Board, all lakes in the city belong to either D or E class. D class water is suitable for propagation of wildlife and fisheries, and E class for irrigation, industrial cooling and controlled waste disposal. Lakes play a crucial role in groundwater recharge, but when untreated sewage is discharged into them, they lose even that function.
Read more: Why apartments in outer Bengaluru hesitate to apply for Cauvery water connection
Cauvery connections may help, but comprehensive solutions needed urgently, say experts
While apartment complexes may not get sufficient water through Cauvery connections, individual households could, says Shashank Palur, senior hydrologist at WELL Labs. Reducing groundwater use in individual houses should be a priority, he adds.
Shashank says the city should use treated wastewater more effectively too. “While the treated water will not be as clean as to be used for potable purposes, it can be used for cleaning, gardening, toilet flushing, etc,. So that a significant amount of groundwater can be replaced with treated water.”
Rashmi Kulranjan, hydrologist and research associate with the Urban Water Programme at WELL Labs, says the rainwater storage capacity of lakes is reducing, and rejuvenation efforts aren’t helping. Bengaluru’s lakes are supposed to be interconnected so that excess water from one lake flows into the next, but blocked inlets and encroached canals instead result in the overflow of water. The annual average run-off is calculated to be as high as 811 MLD. Bengaluru sits on hard rock which doesn’t allow much water to percolate, and the high volume of run-off further hinders rainwater storage and groundwater recharge, Rashmi says.
Rashmi and Shashank also suggest monitoring groundwater extraction and reducing pipeline leakages.
Vishwanath says BWSSB’s study doesn’t address the real challenge which is water scarcity among the poor and the lack of legal and institutional frameworks to address this. While BWSSB claims its report is the first-ever city-specific scientific study in India aimed at tackling water shortage, Vishwanath says the study is just technical. “Everybody knows that the BWSSB connections are limited in the peripheral areas and that’s what is causing groundwater depletion there. Also it is well known that these areas would be hit by water scarcity in the summer as it’s been happening for the past few years. The report has nothing new to offer.”
Vishwanath says that the study should have formed the base for a robust institutional, legal and technical framework for integrated urban water management. This includes using freshwater, wastewater and stormwater as components of a holistic water management plan, and the government working with local communities to develop and implement it. “While the rich can buy water by paying, what will the poor people do? They are the ones who are most vulnerable and going to be hit by this. What about people who live in small huts, pavement dwellers and rag pickers?” he asks.
Water experts’ recommendations for immediate action:
- Lake rejuvenation that could help improve groundwater levels
- Accelerate setting up of decentralised sewage treatment plants (STPs)
- Recharging wells, installing percolation pits and other recharge structures
- Increasing green space and permeable surfaces to allow water to percolate and avoid surface run-offs
- Monitoring groundwater extraction and reducing pipeline leakages
The article is well researched and presents Bengaluru’s water supply position in detail and is indeed of great concern. I had taken some data from a BWSSB’s Vision 2050 document which was then available on their website. To summarise:
First of all Bengaluru’s near total dependence on Cauvery water remains a source of great concern for future water security. Cauvery being a rain fed river Bengaluru’s water resource is highly Monsoon dependent. Therefore the cycle of deficiency of supply from Cauvery due poor Monsoon is true for all times.
Cauvery Water as per BWSSB is capped at 26.7 TMC from present upto Year 2051. At this level, BWSSB indicates, there was a shortfall compared to demand even in 2023.
For Year 2031 with a Population estimate of 14.3 Million, the Projected Shortfall is indicated as 10.69 TMC. This shortfall continues to increase to 26.16 TMC for Year 2051 for a Population of 20.5 million
The Vision 2050 document did not spell out exact staretegy and plans to make uo for the shortfall.
Unless, we plan and invest in every measure possible to meet this challenge – rejuvenation and interconnectivity of lakes, rain water harvesting, reuse of treated waste water etc. -, water security spells great gander for Bengaluru’s sustained development.
Unfortunately, the Government’s obsessive focus on road infrastructure – recently announced tunnel roads, elevated roads, PRR etc -estimated to cost over 75000 crores, is at the cost of ignoring issues like water security.