Bengaluru, Oct. 6 -- A simple, low-cost device is quietly making a big splash in Bengaluru's fight to save water: tap aerators. These tiny fittings, attached to taps, are now helping schools, apartments, offices, and malls cut water usage by thousands of litres every single day.

After the Bangalore Water Supply and Sewerage Board (BWSSB) made aerators mandatory for bulk users last year, the city has seen a sharp rise in installations, said a report by The Times of India. Over 15 lakh aerators have been fitted across Bengaluru so far. Those who don't comply, including apartment complexes and commercial buildings, face fines of Rs.5,000 and even reduced water supply.

Authorities have saved close to 100 million litres of water per day sinc...