Thursday, July 11, 2013

Bountiful water.

A few days ago my wife sent me a research report on the depleting ground water in Goa. As the ground water depletes due to incessant usage, it is being replaced by sea water, which is slowly percolating in from the nearby Arabian Sea. In India since 1980's 21 million wells are drilled with a million added each year. This has helped in doubling of land irrigated by them, from 20 million to 40 million hectares. About 250,000,000,000 Cu. meters of water is extracted each year, which is 40% more than the water replaced by rains. Hence inevitably the water table is falling in every state of India. In Gujarat by 6 to 30 meters each year, some bore-wells, 400 meters deep are running dry. In Tamilnadu wells are drying up daily across the state and half the land has been lost in a decade. In Maharashtra, deep wells have taken ground water for sugarcane plantations and public wells have run dry. In Madhya Pradesh, the once water rich Malwa plateau is now dry and 9/10th of the wells drilled last year are not functioning. Food production is not yet faltering, mostly because dams are being built to compensate for the falling water table, and they supply water for irrigation. A few weeks ago, on a post here on Uttarakhand floods, when I mentioned 600 dams are being planned in that state, a friend of mine asked me, what was wrong with dams. Politicians and dam planners, ask people to give up land to build dams. Many a times this land is also occupied by pristine ecosystems and wildlife. The carrot here is the dams will do three important things- Generate electricity, prevents floods and yield water for irrigation. The problem with this promise is that a dam can't do all three at the same time. For electricity, the dam lake needs to be a full as possible, so maximum energy is available to spin the turbines. But if the lake is full, it will over flow if flood waters run into it and the flood will continue downstream. Irrigation water taken out of the lake, which will peak in summer months, when the lake is not full anyway is in direct competition with electricity generation. Dams which have the additional burden on preventing siltation have the silt deposited at the dam lake. So dam managers try to flush out the sediments by suddenly releasing water and the people living downstream are seldom warned, as has happened in Hirakud dam. With poor water management and lack of awareness among citizens, the situation can only worsen. Just to know where water is used here is a rough scale. It takes 2.8 tonnes of water to make a single cotton t-shirt, 1 tonne for 1 kilo wheat, 3 tonnes for sugar, 4 tonnes for milk, 20 tonnes for coffee and 24 tonnes for a kilo of meat. We cannot take water for granted anymore. Water will soon turn out to be more precious than oil.

Here is the link I mentioned  Seawater entering Goa's ground water

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