Is transporting water from Linganamakki dam in Shivamogga district, 425 km away, the only way to slake Bengaluru’s thirst? While irrigation experts argue that this is the most practical option, environmentalists say that Bengaluru has the resources; they just need to be harnessed.
The Linganamakki proposal, which is part of the B.N. Thyagaraja-led committee report of 2014, has been resurrected with Deputy Chief Minister Dr. G. Parameshwara on Monday ordering a detailed project report (DPR). The proposal is to draw 30 TMC ft. of water from the reservoir in Phase I and later augment it to 60 TMC ft.
This comes in the wake of a recent report by NITI Ayog which stresses on depleting groundwater resources across the country, including Bengaluru.
Irrigation expert Prof. N. Narasimhappa said that though diverting water from Linganamakki is costly, it is the best solution as there is already a dam, built in 1964, with the highest storage capacity in the state at 151 TMC ft., with not a drop being used for irrigation. “In a water-deficient State, exploiting water only for power and letting all river water into the sea is criminal under-utilisation,” he argued, adding that Cauvery had been over-exploited. He further said that more than 30 TMC ft. could be drawn, and drinking water supplied to surrounding districts.
The counter argument has been that Bengaluru has not been harnessing its resources and instead diverting river water from various other regions – Cauvery, Yettinahole and now Sharavathi. Experts prescribe a slew of measures, including rainwater harvesting, recycling wastewater and rejuvenating lakes.
Dr. T.V. Ramachandra from the Centre for Ecological Sciences, Indian Institute of Science (IISc.) said that while Bengaluru’s projected deficit is pegged at 18 TMC ft., harnessing rainwater will yield 15 TMC ft. and recycling wastewater will yield another 16 TMC ft.
S. Vishwanath, a proponent of rainwater harvesting, batted for the Linganamakki proposal as the most practical solution with the least ecological damage.
“Harnessing even 60% of rainwater will give us 1,500 Million Litres of Water per Day, making the Linganamakki proposal unnecessary. But going by our experience over the last 20 years, the systems are incapable of achieving this,” he said.
‘State can afford to compromise on power production at Sharavathi’
One of the main concerns of diverting water from the Linganamakki dam to Bengaluru is whether it will affect power generation in the State from the Sharavathi river basin, a major source for hydel power.
Linganamakki dam was built across Sharavathi river and is exclusively used for hydel power production.
Industry experts say that with power generation from alternate sources, like solar, being augmented, the State can afford to take a hit in the hydel power component. Moreover, the contribution of the power generation stations that will be hit by diversion of water to Bengaluru to the total installed capacity in the State is a meagre 5.3%.
As on May 31, 2018, the total installed capacity of power utilities in the State was 26,697.47 MW, as per the latest report of the Central Electricity Authority, of which 3,599.80 MW is from hydel sources. Three power plants — Sharavathi, Gerusoppa and Jog — that contribute 5.3% to the power generated in the State, will be affected by the diversion of water.
“The augmentation of solar power capacity in the State will soon make us power surplus. The State's power scenario is in a position to afford a hit in the Sharavathi river basin,” said M.G. Prabhakar, member, Karnataka Electricity Regulatory Commission Advisory Committee.
Project likely to face pushback from Sharavathi Valley
The proposed project is likely to see pushback from environmentalists and locals in Shivamogga along the lines of the Yettinahole project. Environmentalists have already threatened to challenge the proposal in court.
Many argue that it comes at a time when concerns are being expressed on poor rains in the Sharavathi river valley owing to destruction of forests. Since construction of the reservoir, the water level has reached the brim only 14 times, and the last occasion was in the year 2014. In the past three years, the reservoir had not received even half of its total capacity of 151 TMC ft.
“It would damage the ecology of the region, as large tracts of forest would be destroyed for construction of jack wells and to lay the pipeline,” said B.M. Kumaraswamy, environmentalist and member of Vruksha Laksha Andolana.
Dr. T.V. Ramachandra, Centre for Ecological Sciences, IISc., Bengaluru, said water was already depleting in the river basin. The tailend areas had already seen depletion of fish, hitting livelihood, increase of salinity, which will only increase with further diversion, adversely impacting agriculture yield.
