Wednesday, December 22, 2010

Groundwater levels improve in the Capital (Hindu 23 December 2010)

‘Recent rainfall has managed to bring the levels of groundwater higher in almost all regions'
Heavy, almost unprecedented, rain that the city received this year has recharged the groundwater level by almost 10 per cent.
The groundwater level in the city has been falling at an alarming rate, and seven of the nine districts have been declared “over exploited” by the Central Groundwater Board.
According to data collected by the groundwater authority, the recent rainfall in the city has managed to bring the levels of groundwater higher in almost all regions, including the worst-affected areas in South and South-West Delhi.
Vinod Jain of the non-government organisation Tapas that procured the data using the Right to Information Act said the rainfall has been a boon, since usually it is the groundwater that feeds the river, but this year the rain-fed river was in spate and allowed the recharge of water level.
“Since 2004 we have noticed that the groundwater level has been reducing after the monsoon. This is the first time that after monsoon the groundwater level has increased in most of the location. And because there was so much water in the Yamuna, it really helped in the recharge,” said Mr. Jain.
The data shows that even in areas where embankments have been raised on the floodplains, the water level has shown improvement.
“It is a huge validation to what we have been saying that the floodplains are an important recharge area and should not be concretised. We have seen that groundwater level near Akhshardham Temple, Mayur Vihar floodplain, Nizamuddin Bridge floodplain have shown improvement. For instance, near the temple the levels were at 6.26 metres below ground level (mbgl) in November 2009 and during the corresponding time in 2010 the levels were at 0.3 mbgl. Similarly, near one spot near Nizamuddin Bridge the level in November 2009 was 5.18 mbgl and in 2010 at 1.13 mbgl,” said Mr. Jain.
The rise in groundwater level has been most discernible in East Delhi where at some places there was a very high rise in level.
“We saw in some East Delhi areas the groundwater level rose abnormally affecting basements and structural safety of buildings. A battery of tube-well should have been installed to de-water the areas affected near the embankments of East Delhi for ensuring safety of the buildings,” pointed out Mr. Jain.
A building in East Delhi's Laxmi Nagar collapsed when its poor construction was made worse by accumulated water in the basement.
Mr. Jain said conservation steps like rainwater harvesting and revival of water bodies like the lake in Bhalswa have also contributed to this rise in groundwater level. “There are several areas where the levels have improved also because of water harvesting, for instance in the Shram Shakti Bhawan complex where a water harvesting system is in place.”
The areas that have shown marginal or no improvement are the ones where piped supply of water is not available and the consumers are largely dependent on tube-wells. “Areas, which are not connected with Delhi Jal Board's network, mostly the outer areas and urban villages in South have shown a rise, but the levels continue to remain critical,” he said.
Among the worst affected areas are Asola farms where the current levels are 42.67 mbgl, Lado Sarai at 60.41 mbgl, Saket D block at 61.78 mbgl Tehkhund at 42.06 mbgl.

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