Waterlogging helps water harvesting.

Byline: Sudeshna Chatterjee

New Delhi: Even bad planning has its advantages. Take waterlogging, for instance. Clogged drains and the absence of a proper drainage system will result in the collection of rain water at 135 places in the city this monsoon. The Delhi Municipal Corporation (MCD) has admitted as much. It will cause traffic snarls, disruptions in electricity supply and a civic mess in general that will take days to clear.

But it will also provide a splendid opportunity to recharge ground water levels by harvesting the rain water collected at those spots.

The main areas where waterlogging will wreak havoc are the ITO crossing, Mathura Road, on the Ring Road outside the School of Planning and Architecture, Greater Kailash, Alaknanda, the Ashram crossing, Sainik Farms, parts of Rohini, Pitampura, Boulevard Road, South Extension and Model Town.

''This waterlogging menace can easily be converted into a solution for recharging ground water by installing simple structures,'' says a Central Ground Water Board (CGWB) scientist. For example, houses in a 2,000 square metre area in Sainik Farms were battling severe waterlogging every monsoon till the CGWB got into the act and drew up plans for creating a solution, literally. It first estimated the potential of the area. ''We found that if the rain water collected in the area could be effectively utilised, it would generate 630,000 litres of ground water every year. This quantity is enough to meet the requirements of 17 people for an entire year,'' the CGWB scientist said.

Delhi gets an annual rainfall of about 70 cm. Given a surface area of 1,485 sq km, the total potential of rain water harvesting is 104 million litres every year. Of this, roof-top harvesting structures can recharge about 90 million litres. The balance - 14 million litres - can be recharged by other systems, including those on or near waterlogged roads. But there are as yet no estimates of just how much water actually collects on roads.

MCD additional commissioner Ramesh Negi says: ''Of the 135 points we have listed out ...