Why Sharavathi water for Bengaluru, ask experts

SHIVAMOGGA: With the Karnataka government looking at the Linganamakki reservoir to divert Sharavathi water to Bengaluru to meet the increasing demand for drinking water, experts are raising questions about the feasibility of the project, as it poses a threat to the environment.

In June first week, it was Chief Minister H D Kumaraswamy who had directed the authorities to come up with a proposal to supply 18tmcft of water from Tunga and Bhadra rivers to meet drinking water demand. On June 20, deputy CM Parameshwara asked for a detailed project report (DPR) on channelling Sharavathi water to Bengaluru, a distance of 430km.

Linganamkki reservoir in Kargal village of Sagar, constructed across Sharavathi river, has total storage capacity of 151.75 tmcft and generates a total power of 5,000 Million Units from the Sharavathi valley.
Water level in Linganamakki reservoir is about 1,819 ft above sea level when it reaches its maximum level. Bengaluru is situated about 3,000 ft above sea level.

“Expecting that water will be lifted from Linganamakki after the rainy season, during which process the level in the reservoir also comes down. So, water has to be lifted for about 1,500 ft above sea level and then pushed to reach a distance of 430 km. So, it is not a viable idea to take Sharavathi water to Bengaluru,” said Gajanana Sharma, retired superintendent engineer, KPTCL, who has worked at the Sharavathi valley site for many years.

“The gross head of the existing design of the turbine in Sharavathi valley is 1,525 ft. It requires 10 cusecs of water to produce 1 MW of power, using this head. So, to lift and pump the water from the reservoir
requires an equal amount of power, and additional power to take water for about 430km,”he said.
Sharma said if the government plans to lift 10 tmcft, it will lose 300 MU of energy generation in Sharavathi. Power leakages along such a long route and other issues have been accounted for. Considering these, the government can think of developing a town which has all basic infrastructure, he said.