Chennai: Rain fills sumps, but water table at rock bottom

CHENNAI: Rain after almost 200 days did a few things – it brought down the searing temperatures, partially filled water bodies such as temple tanks and ponds that were bone dry for two months and sensitized residents about rainwater harvesting.


If many in Chennai put out pots to ‘catch’ the rain amid a heavy downpour on Wednesday evening, resident associations are now coming together to set up rainwater harvesting structures, something they have not done for years. At

Mogappair West

, Golden Fortune Southern Enclave Owners Association is meeting on Sunday to find a solution to the crisis its 500-plus residents are facing. “Our wells have very little water and the borewell water is not usable. We will harvest every drop of rainwater from now,” said V Santosh, the association secretary. “Harvesting could bring down the salt content in the borewell water as well,” he said.

Hydrogeologist J Saravanan

said those who understood the importance of rainwater harvesting are reaping the benefits, although little. “In buildings where the structures have been maintained, the quality and quantity of water will improve.”

At the women’s hostel at College of Engineering, Guindy, water collected on the roof enters a filter chamber and then into a 36,000-litre sump. But the recent rain brought in 36,000 litres and the sump overflowed.

At the Guindy National Park, wildlife officials said the rain partially filled six ponds. The tank at the Kapaleeswarar Temple in Mylapore has some water now.

While small changes were visible on the surface, the rain would not make any difference below it, said Metrowater officials.

“Only the permeable layer would have got wet in the rains and around 20% of the water would have been absorbed,” said an official.

The city has clayey soil and sandy soil in different areas. While water would be absorbed by clayey soil instantly and percolate into the aquifer, in areas with sandy soil, water will take a couple of hours to percolate. “But that said, only after a couple of heavy showers an improvement could be recorded in the soil,” the official said.