Taking a trip down memory lane: This lake was Bengaluru’s first water source beyond its boundary

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 Reservoir next week.

The Hessarghatta scheme was initiated keeping the growing population of the British cantonment and the pete in mind.

The Hessarghatta Reservoir was created in 1892 after an irrigation tank bund — of 1532 vintage — on the Arkavathi river was renovated. Mysore dewan K Seshadri Iyer, along with chief engineer MC Hutchins, called the scheme Chamarajendra Water Works, after the maharaja.

“A brick aqueduct carried water up to Soladevanahalli. Steam pumps and electricity was used for the first time to pump the water up to Chimney Hills, from where it flowed by gravity to filters at Hebbal and Malleswaram,” said Vishwanath. Water from this project flowed to the city for the first time in June 1896.

When the project was initiated in 1892, the population of the city was 1,80,366 (as per the National Archives, 1931). The water from Hessarghatta was estimated to be adequate only for 2 lakh people at the rate of 10 gallons per head per day for a period of 20 years.

Harini Nagendra, professor of sustainability at the Azim Premji University, has written how Bengaluru’s population exploded to 2,37,496 by 1921. “The consumption amounted to 13 gallons per head per day. To deal with the crisis, rationing of water to 10 gallons per person per day was initiated.” To augment water supply, nearby tanks including Madura and Kolathur were also breached.

Hessarghatta, however, went dry. The reason was deterioration in catchment characteristics. It was full, for the last time in 1994, and gradually stopped being a water source.