WHY DELUGE MISSED DELHI.
So, as an early monsoon and the release of more than 11 lakh cusecs of water by Haryana caused the Yamuna to flow above a threatening 207m, more than two metres above its danger mark, the damage remained restricted to low- lying areas around the river.
A senior official of the flood control department said the 10 bunds -- measuring between 203.8m and 216.2m -- run along the river's entire span -- from Palla in the North to Jaitpur in the South. They are: the Rural Marginal Embankment ( RME) from Palla to Wazirabad; Jagatpur bund from Jagatpur to upstream of Wazirabad Barrage; Yamuna Bazar Wall -- upstream of Old Railway Bridge; Madanpur Khadar near Okhla; Left Forward bund, which runs from the Delhi- Uttar Pradesh border up to Wazirabad; Shahdara Marginal from Wazirabad to Old Delhi Railway Bridge; Left Marginal bund from Old Railway Bridge to Noida; Power House bund; and Mughal bund.
But even as they admit the bunds have guarded the city against floods over the years, experts say swelling beyond a certain level may render the embankments useless.
" Water has never reached the level of 1978 ( when Yamuna flowed at 207.49m). When it www. mailonline. in READ MORE @ does happen, many areas, particularly in East Delhi, will be at risk," said Manoj Mishra of the Yamuna Jiye Abhiyan.
" Even in the flood of 2010 ( Yamuna breached 207), water crept into basements of flats in Lalita Park area. This time, too, the water managed to reach Ring Road near ISBT," he added.
Mishra said despite the embankments, construction on the river bed has made many areas vulnerable. " In 1978, 10 lakh cusecs of water was released ( from Haryana's Hathnikund barrage), and such a thing has never happened since. But in the past couple of years, we have seen major construction work on the river bed, for example the CWG village and that related to the Metro," Mishra said.
Analysis shows that while RME Palla meets the requirement to withstand a 25- year frequency flood ( flood of an intensity likely to be witnessed once in 25 years), Jagatpur Bund, Yamuna Bazr wall, Mughal bund, LF bund, SM bund and LM bund all fail to meet the standard and are unlikely to restrain the swelling river in such a scenario.
In the eventuality of a 100- year frequency flood, all these embankments would fail to save the city entirely.
Bunds built along the Yamuna keep its waters from flooding Delhi
MAJOR FLOODS IN DELHI
1978: Officials say it is the biggest ever flood to have hit Yamuna. North Delhi colonies along the river, namely Model Town, Mukherjee Nagar and Nirankari Colony, among others, had got submerged
1988: Waters from a heavily flooded Yamuna inundated many villages and localities such as Mukherjee Nagar, Geeta Colony, Shastri Park, Yamuna Bazar and the Red Fort area, affecting thousands of families
1995: Heavy rain in the upper catchment area, and release of water from Tajewala waterworks flooded the Yamuna. Fortunately, the flood did not coincide with heavy rain in Delhi, and could be contained within the embankments
2010: Ahead of Commonwealth Games, incessant rain and release of water from Haryana led to flooding of lowlying areas ( in pic). Ring Road near ISBT remained submerged for two days
ALTERNATE SHIELDS FOR CITY
The installation of more drains in Delhi is in the works to drain out lowlying rural areas. The areas are currently served by important drains such as Mungeshpur, Nangloi, Burari Creek, Karari Suleman Nagar, Bankner, Sanoth Link, Shahdara, among others.
They need to be desilted before monsoon every year to work properly
Officials say proper drainage systems are yet to be developed in unauthorised colonies, which is why, currently, rain water is left to stagnate in pools and low- lying plots. For the stagnant water to be drained, a battery of pumps has to be installed to transfer the water to nearby drains
For authorised colonies, there are proper drainage systems maintained by concerned civic agencies
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