Perhaps the least known feature of Kanakapura Road is what serves the city the most — the Bangalore Water Supply and Sewerage Board's (BWSSB) pumping station at Tataguni, distributing water to the city all day, all week, through the year. Sourcing water from the Cauvery, at the point where its tributaries Kollegal and Kabini meet in T. Narsipur, 120 km south of Tataguni, water is supplied to Bangalore city through three pumping stations on Kanakapura Road. This system forms the famed Cauvery project that the city depends on.
Journey against gravity
“When water flows from the Krishnaraja Sagar to T. Narsipur, part of it is drawn to Thorekadanahalli (T.K. Halli), where BWSSB's treatment and purification plant is stationed,” explained Rama Krishna, the engineer in charge at Tataguni. “From T.K. Halli to Harohalli, where the next pumping station is located, water flows on gravity only and does not need to be pumped, for a distance of 25 km.”
At Harohalli, there are no chemical processes for the Cauvery water to undergo. “From Harohalli, underground pipelines, of 1,200 mm width, bring the water to Tataguni,” Rama Krishna said.
This stretch of the water's journey is steadily against gravity, overcoming an altitude of 1,500 ft. All three stages of the Cauvery water project put together, Tataguni pumps 590 million litres of water a day (mld) to the city.
An engineering feat
“The Cauvery water project is truly an engineering marvel,” exclaimed S. Vishwanath, founder of Rainwater Club. “Pumping water for a whole city over 100-odd kilometres, climbing an altitude of nearly 500 m is a challenge the BWSSB took on and completed successfully.”
The pumping station at Tataguni is deceptively and almost disappointingly small and non-descript for the immense task it performs.
A small winding road leads to the station, amid a carefully landscaped wooded area. Large closed tanks, which still do not appear massive enough to hold water sufficient to quench a whole city, receive water from the pipelines.
The fumes released as a result of chlorine being mixed with the water ensure that people keep their distance.
Energy intensive
A large room is demarcated notionally midway to separate the five pumps that work on stage I of the project from an equal number of pumps that are for stage II. These two stages pump 135 mld of water each, while stage III, which is another series of eight pumps in another room, pumps 320 mld of water, 50 mld in excess of its actual capacity of 270 mld.
“We pay an electricity bill of Rs. 7 crore a month, to do all this pumping,” Rama Krishna said.
“Bangalore attracted people as a settlement, because of its salubrious weather, which it gets by being at a certain altitude,” Vishwanath explained. “As with all hill stations, the city does not have too many water sources nearby to fall back on, and cannot hold much water in its soil.” Hence, such energy intensive processes become necessary to sustain the growth of such a city, he said.
There was the Arkavati, which has now dried up, and supplies very little water to the city. “We should do rainwater harvesting and recharge our lakes, of course. But, water is not an easy resource to access for Bangalore,” Vishwanath said.
Ironically, Thatguni village and settlements near the pumping station do not get Cauvery water as the city limits begin only at Talaghattapura, further up Kanakapura Road.
Alternatives
Rohan D'Souza, who conducted research on water systems in Bangalore last year, however, does not think of the Cauvery water project as a necessary evil.
“If people in the 16th century could think up of a system of tanks to sustain their settlements, we should be able to maintain them and expand them more and not have to pump water from 100 km away,” he said.
“People are sold to the idea of the Cauvery itself coming to their homes,” said Vinay Baindur, a water policy analyst. “It becomes a matter of culture and even religion for them.”
“There were some water recycling plants and other alternative ideas proposed to meet the demands of central Bangalore,” he said. “But, all of it was consumed by the idea of a massive water supply project that is the Cauvery project stage IV, which would focus on the suddenly grown areas of outer Bangalore.”
Published - May 16, 2012 04:46 pm IST
