An expert committee set up by the State government has recommended drawing of water from the Linganamakki reservoir in Shimoga district to tackle the drinking water needs of Bangalore city.
In its report submitted to the government recently, the 10-member expert committee headed by B.N. Thyagaraja, former chairman, Bangalore Water Supply and Sewerage Board, recommended drawing of 30 tmcft water during 2021-51 from the Linganamakki reservoir, built across the Sharavathi in 1964.
The hydro power generating units at the reservoir has an installed capacity of 1,330 MW. In the first decade (2021-31), the estimated cost of drawing 10 tmcft of water from the reservoir would cost Rs 12,500 crore. The Lingamakki reservoir was most suitable for meeting the drinking water needs of Bangalore as its water was unpolluted, the panel observed.
The committee said if the reservoir is delinked from power generation even partially, the drinking water supply needs of not only Bangalore but also other towns in the districts of Kolar, Chickballapur, Bangalore Rural, Ramanagaram, Tumkur and Chitradurga could be fully met.
The reservoir, which has a storage capacity of 151 tmcft, was built only for the purpose of hydro electricity generation. The panel recommended withdrawal of 60 tmcft of water, which would amount to only 40 per cent of the total reservoir capacity. The remaining water could be used for power generation.
It said that if the government undertook a policy decision to partly convert the power generating reservoir for drinking water supply, the entire needs of Bangalore up to 2051 could be met by the reservoir alone.
There would be reduction in power generation but power could be generated from other alternative sources to meet the demand. Only pipelines have to be laid with a pumping station at Linganamakki, the panel said.
The panel estimated that the Bangalore city’s population would reach 1.42 crore and 3.45 crore by 2021 and 2051 respectively, while the demand for drinking water would touch 36.4 tmcft and 88.25 tmcft respectively during the same period. At present 18.8 tmcft of water was being drawn to the city and the shortfall would be 17.6 tmcft in 2021 and 69.45 tmcft by 2051, it said.
Other major recommendations included steps for reduction in unaccounted water supply in the city, revival of flow of water in the Arkavathi, rejuvenation of tanks and adoption of rainwater harvesting to recharge groundwater, laying separate pipelines for potable and non-potable water and drawing of water on short and long term basis from the Cauvery.
