BENGALURU: The torrential downpour that lashed the city has left many Bengalureans exasperated with loss of lives and property. However, city-dwellers do stand to benefit from the rain as they might get drinking water from the Thippagondanahalli (T G Halli) Reservoir soon.
The reservoir is now brimming with water. The project, located 35 kms from the city on Magadi Road, is close to the storage level it had attained 21 years ago. Thanks to the copious rains, the heavy concentration of salts in the water has been diluted, thereby brightening the prospects of supply of drinking water to the city.
“The level of water in the reservoir touched 54.10 feet (54 feet, 10 inches) at 4.30 pm on Wednesday and is expected to touch 55 feet later at night,” P N Ravindra, Chief Engineer (CE), Cauvery, Bangalore Water Supply and Sewerage Board (BWSSB) told Express.
“It was just 38.6 feet in May. So, there has been a significant rise in the water level. For the last week, we have been filtering and treating the water,” he said. Given that rains continue up to November here, the storage level is set to increase in the coming weeks, the CE added.
B M Somashekhar, Additional Chief Engineer, said, “Since September 6, we have been treating the water with alum and sodium hypochloride, filtering it and releasing it downstream into Arkavathi. The filtration system, pipeline and pump houses have not been used for seven years and we are now preparing to use them to send water to the city in the future,” he said.
Asked about the chances of augmenting the city’s water supply from the reservoir, Ravindra said: “Due to the inflow of fresh water, the concentration of Total Dissolved Solids (TDS) has been diluted. From 900 milligrams of TDS in a litre of raw water, it has now touched 580 mg per litre. As of now, it is all set to reach 300 miligram per litre, a level considered fit for consumption. More rains are bound to dilute the concentration further, improving the quality of the water.”
The reservoir with a maximum storage capacity of 74 feet is permitted to store water upto 72 feet for safety reasons.“It reached its highest point in 1997,” Somashekhar said. “In 2006, the water level touched 60 feet and 4 inches and this would be reached in the coming days,” he added.
A top BWSSB official in T G Halli said that the rains in August in the catchment area was only around 50 mm. “It has been really heavy in September with 123.4 mm rain recorded on Monday (Sept 11),” he said.
Supply cut off in 2012
T G Halli reservoir (Chamarajasagar Dam) receives water from Arkavathi and Kumudavathi rivers. It was the city’s main source of water since 1933 and supplied 135 million litres of water per day. After the commissioning of the Cauvery Water Supply Scheme in 1974 and the reduced water supply from its sources, the quantum of water drawn from the reservoir was reduced. Supply was shut off in 2012 due to high concentration of Total Dissolved Solids (TDS) in the water, which made it unfit for consumption. The state government had tried several methods to treat the dam’s water to make it potable but had given up due to the exorbitant cost involved.