Hessarghatta lake, located 27 km from Bengaluru, dried up to the last drop at the turn of the millennium. It had been the city’s single source of water for about a century but signs of shortage started from 1907. In the 1920s, a knee-jerk measure to temporarily pump water from the Y-Chetty lake was made. In 1930, a dam was built across the Arkavathi river, around 32 km away, as part of the Thippagondanahalli scheme. This, too, was not enough. Bengaluru was expanding rapidly. Finally, in 1970, the government decided to draw water from the Cauvery river, over 140 km away, which meets the city’s water requirement to this day. This chain reaction of looking beyond local sources, which has resulted in Bengaluru being waterscarce, began with the Hessarghatta (also spelt Hesarghatta) scheme. Historically, the concept of procuring water from far-away sources was unknown to Bengaluru. The dependence was mostly on tanks (Ulsoor, Sampangi, Sankey and Dharmambudhi) and open wells. “By the late 1890s, the tanks got polluted and we started looking for water elsewhere,” said water expert S Vishwanath. He is leading a heritage walk for the Indian National Trust for Art and Cultural Heritage (INTACH) at the Hessarghatta…