TG Halli dam, built in 1933, to supply water to city again

A British-era reservoir that once supplied water to Bengaluru is coming back to life, thanks to copious rainfall this monsoon.

The Thippagondanahalli reservoir, on the city's northern outskirts, is just a few feet short of its maximum capacity of 72 feet.

With the water level rising to 68.7 feet, the BWSSB is gearing up to resume supply to the city, stopped in 2012.

TG Halli dam, as the reservoir is popularly called, was built in 1933 at the confluence of rivers Arkavathi and Kumudavathi.

It was the first source of piped drinking water to Bengaluru, and was named Chamarajasagara, a name now almost forgotten.

BWSSB's assistant engineer Ramakrishne Gowda S said the water level was just 42 feet four months ago.

"It has received record rainfall after about 15 years. The sluice gates built during the British era are opened when the level goes beyond 74.6 feet," he added.

That level was last breached in 1997-98, by his reckoning.

The decision to resume supply from the dam was taken after the quality of water in terms of TDS (total dissolved solids) was measured.

"The raw water shows less than 500 mg/litre of TDS, which is the standard level for supply. After treatment with alum and sodium hydrochloride, the water goes through sand distilling, the traditional method here," said Chethan M S, chemist, TG Halli dam.

When DH visited the treatment plant, the rusty equipment were in the process of being repaired.

"We have estimated Rs 2.5 to Rs 3 crore as requirement to execute repairs and maintenance. Once the funds are released, we will take a month's time to resume supply," said B M Nagendra Babu, assistant engineer, BWSSB.