With activists opposing the Yettinahole project all set to launch a hunger strike on Friday fearing that the project will dry up the Netravathi, a senior professor of the Indian Institute of Science (IISc), Bengaluru, has come out with a project to save the river and its tributaries without abusing them in any manner.
According to T.G. Sitharam, a senior professor in civil engineering, IISc, flood water from the Netravathi, between June and September, could be stored by constructing a reservoir in the Arabian Sea in the city by using available technology, including constructing breakwater. Later, it could be utilised for drinking and irrigation purposes. Breakwater technology had been adopted in Mangaluru earlier to prevent sea erosion.
Speaking on “Building flood water coastal reservoir in the Arabian Sea” here on Tuesday, the professor said that more than 120 tmcft of flood water ran off to the sea every year from the Netravathi. Of that, 10 tmcft or 15 tmcft of water could be stored by building coastal reservoir and the rest could be let off into the sea as flood water is compulsorily required for nourishing marine life. It could be built through public-private-partnership and it might cost between ₹ 3,000 crore and ₹ 3,500 crore.
He said that Mangaluru required about one tmcft of water annually for a five lakh population. According to him, building a small coastal reservoir just to store one tmcft of water was not viable as it involved pumping of water out from the reservoir during the rainy season to prevent flooding.
Of the four different possible schemes for building the reservoir available, constructing one outside the mouth of the river in the sea was viable, he said.
Prof. Sitharam, who is also KSIIDC (Karnataka State Industrial and Infrastructure Development Corporation) chair professor in the area of energy and mechanical sciences at the IISc, said that the size of the reservoir could be decided as per the requirement which could also be extended in stages if more storage space was available.
To a question, he said that a flexible floating membrane could be fixed to the breakwater to prevent mixing of salt water with fresh flood water.
He said that he has submitted a proposal to Chief Minister Siddaramaiah.
