(Feature Image: People stand in a queue with water cans to get drinking water at Jnana Jyothi Nagar, in Bengaluru. Image Source: PTI/Live Mint, 10 March 2024)

One central lesson of the ongoing Bangalore water crisis is essentially that ignore groundwater sustainability at your own peril. The surface water availability in Bangalore has not decreased, it is the groundwater depletion that is leading to crisis. There is of course the expansion of the city both horizontally and vertically that is increasing demands, but simple arithmetic tells us that if groundwater levels are sustained, it can take care of these increased demands.

The Groundwater sustainability includes sustaining the groundwater recharge and ensuring that extraction does not go past the recharge. Sustaining the groundwater recharge means first understanding the groundwater recharge mechanisms, zones and protecting them. BDA has been sitting for four years on desilting of two lakes: Bellandur and Varthur, which has caused huge impact on groundwater depletion. It also means increasing the groundwater recharge through rainwater harvesting (Bangalore’s failure here is apparent from the fact that government is collecting crores of rupees as fines from those not following the mandatory rainwater harvesting requirements), groundwater recharge wells and diverting tertiary treated sewage, available in Bangalore of upto 300 Million Liters per Day, to lakes and other such recharge zones.