Bangalore’s potable water supply – the math is failing The issue of Bangalore’s potable water supply used to be an obsession of mine when I was a young journalist in the city. I studied and wrote about it a lot from a landscape perspective. This obsession also came from an early childhood in the city that was water strained and all of us kids used to fill every container we knew with water when there was supply! Summer 2024 looks bad – very bad, East Bangalore is going to be worst affected with water shortages. And that got me crunching the numbers again after many years. This is not just about one failed monsoon in 2023. The potable water supply scenario of the city is poised to enter negative territory even with normal or surplus monsoons in the future. Read on… There are no exact estimates for potable water demand in Bangalore but its estimated based on current supply. Currently the BWSSB supplies ~ 1450 Million Litres Daily (MLD) + the city extracts almost half of that 700 MLD (crude guesstimate could be way more!) from borewells. Picture this – half a daily Cauvery supply of borewell water is extracted daily in Bangalore! Most new property developments in Bangalore rely 100% on groundwater. Even our apartment in Bangalore, built in 2002, received piped water supply only in 2014-15 (lag of almost 15 years). At least 1/3rd of the urban areas and most peripheral urban villages still don’t have piped water. Piped water supply has been lagging in the city since – 1960s! Incrementally at great expense the Cauvery river, 90 kms south of Bangalore has been tapped and water pumped almost 1000m uphill to Bangalore. Bangalore’s water is probably among the most energy inefficient on the planet, every drop is pumped up using many megawatts of electricity – either from the Cauvery or underground. Since 1974, it has been a forlorn chase when demand forecasts and supply never meet. One thing is the BWSSB has always been good at is showing how big is the shortfall. It’s an organization in an unenviable position. It spends almost 80 pc of its revenue on electricity to pump water and knows that soon there won’t be any more it can pump. There is a Cauvery Stage V water supply that might begin this year supplying a maximum of ~750MLD in phases, but that is the END. The Cauvery is fully tapped out for now and can’t spare a drop more for Bangalore. So that is 1450 + 750 = ~2200 MLD (in a normal monsoon year) from the Cauvery + ~700 MLD (negatively trending) from groundwater. The problem here is that the BWSSB only estimates demand from ‘planned developments’ and the Bangalore’s growth has been anything but that. Till 2021 the estimated planned demand was 2100 MLD and that will be met by 2025 when Cauvery Stage V is fully ON. The unplanned demand is being catered to by groundwater. Total demand right now is ~ 2900+ MLD (the BWSSB predicts this ‘planned for’ in 2031 btw!). The way consumption is growing in the city, it might need 3200-3400 MLD before 2030, which the BWSSB only forecasts by 2041. You see the demand supply gap widening massively? The BWSSB itself now says they don’t have any more planned supply coming. Trust me, there is no other perineal water source that is currently being planned to be tapped for Bangalore at least for the next decade. Cauvery is fixed at 2200 MLD. Where is 1000+ MLD going to come from by 2030? Because borewells are drying up, the ~700 MLD being extracted right now is diminishing. You need mega surplus monsoons to replenish and grow groundwater table. Is that going to happen regularly? Thus, every bad monsoon from now will only be a bigger disaster – less water in Cauvery + even lesser underground. In the next 3-4 years if you have a severe drought and lose 1,000+ MLD, what kind of rationing or prayers can save the population? This summer is going to be a test for the Karnataka government. Bangalore competes for drinking water from the Cauvery with Mysore and irrigation needs of the entire area fed by KRS Dam. In election season this summer whose needs must be prioritized? There is already a clamor from farmers that they need water for standing crops and in the past protestors (and water thieves) have damaged the pipes that supply water to Bangalore. Will the needs of farmers be sacrificed again to supply more Cauvery water to Bangalore by 2030 in Stage VI, VII…? If you plan to live in Bangalore for the long term – start answering this question NOW – where will I get water from in 2035? As of now the government hasn’t a clue about this, this problem is being kicked down the road. My intention in writing this is not to create a doomsday scenario but to make people aware of the problem that has been well-discussed and written about. 2024 summer is the trailer for bigger crises ahead. *** PS: 😆 In a decade North Indians in Bangalore might start heading back north - because even with effects of climate change and 'not so awesome weather', the Gangetic plains will still be water surplus for eons!