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Daijiworld Media Network - Mangaluru
Mangaluru, Feb 7: Coastal Reservoir just near the mouth of river Netravati in the Arabian Sea by building sea walls up to about 14 km length will help store the required water and completely solve the drinking water shortage problem faced by the people of Karnataka according to Prof T G Seetharam, professor of civil engineering and KSIIDC, chair professor in the area of energy and mechanical sciences at Indian Institute of Science of Bengaluru. He said the cost of building a coastal reservoir for storing about 25 TMC of water would cost about Rs 3000 crore.
Speaking at a press meet organised in the city, initiated by BRS Recreation Pvt Ltd promoted by Dr B R Shetty, Prof Sitharam spoke about a new technology involving locking the flood water during the rainy season in the form of a coastal reservoir as the best solution to overcome the water shortage facing the district. He said that the reservoir should be built near the river mouth where it joins the sea with the provision to capture only the flood water and allowing excess flood water to flow into the sea. "By keeping out sea water by construction of sea wall along with required sluice close to the mouth of the river forms the fresh river water reservoir in the sea," he stated.
He also pointed out that Netravati gets about 120 TMC of rain water in just four months which he said runs off to the Arabian sea. If we impound this flood water it would help overcome the water shortage faced by the entire city. "Coastal reservoir will increase Mangaluru’s fresh water supply sources for generations to come," he said.
"When India has achieved considerable progress in IT and BT and is on par with the US and other developed countries we are equivalent to Ethiopia when it comes to storage of water available per person in our country. Moreover, whatever little water storage we have is only used only for power generation," he added.
He further pointed out that 54 percent of India is facing high to extremely high water scarcity and among the options of fresh water source available are limited to surface water, sub surface flow, ground water and sea water. "What Indians are facing is actually not shortage of water but lack of storage of water or lack of water management. Mangaluru is not running out of drinking water as is being said. In fact water is running out of Mangaluru," he said.
Speaking about the options available to store the fresh sources of water available in the coastal region he said the best and feasible option available is to opt for sea based fresh water reservoirs. Pointing out that India is third in terms of number of dams built in the world he said, "Building dams involves displacement of people and villages and there is also the problem of silting reducing the storing capacity to only 75%. Construction of dams has inflicted severed damage to the river echo system and therefore we cannot go for building more dams. Desalination is quite an expensive process and the high salt content of the residue will be will be ecologically harmful as it would kill the marine life. It is still a taboo among Indians to use recycled water even though it is much cleaner than most of the water available for us. Taking these aspects into consideration the only feasible option available for us is to go for sea based fresh water reservoirs."
Comparing the cost involved in the construction of sea based water reservoir Prof Sitharam opined that sea based reservoirs will be able to supply water at an average of Rs. 2 per kilo litre that also includes the cost of construction of the reservoir. This is quite economical and is also environment friendly as compared to the desalination process which might cost about Rs. 70 per kilo litre and Rs. 30 if we go for inland reservoirs. Even if the water is required to be pumped to a distance of 300 kms and elevation of 1000 metres it would be much cheaper than the process of recycling waste water or desalination of sea water, he stated.
Emphasising that coastal reservoir is cost effective without any negative impacts Prof Sitharam pointed out, "There is no harm to the river basin from the reservoir and to the forest cover. There will not be displacement of people or their villages except temporary displacement of fishermen. Diversion of river is not required if sea based reservoir is built and water would be available in plenty for agriculture apart from drinking. However, in case the wall is built inside the ocean the entire length and width of the sea wall will encourage deep sea fishing and would benefit the fishing community enormously." He also said that sea based reservoir would make way for generating solar power in addition to providing fresh water sand in abundance.
Prof Sitharam stated that countries like Netherland, Hong Kong, South Korea, Singapore and China already have sea-based reservoirs. Australia and USA are in the planning stage of reservoir and India too has started Kalpasar project off Gulf of Kambhat, in Gujarath. He concluded saying flood water coastal reservoir is a march towards blue revolution in the country and would be the answer to the water crisis faced by Indians.