|
|
||||||||||||||
Why doesn’t the drainage system in Delhi work? |
||||||||||||||
 Well, keeping in mind the population of any city, the drainage system is built in order to keep pace with the city’s concretization, which increases in direct
relation to the population. Given the complex network of storm water drains that Delhi seems to be equipped with, one doesn’t expect that it would be so severely plagued by water logging
issues. However, despite the city’s ever increasing crowd, there has been no change in the drainage system plan, which means fewer drains for more waste. That in turn
implies that although more and more waste is generated every day, there aren’t enough channels to take that kind of load. There are several other issues too – damaged/absence of drain lining, construction debris like cement and other waste like plastic bags clogging the drains.
Added to that, storm water drains, which are specifically meant to carry rain water, are used to carry sewage water too. Sushmita Sengupta, a local water expert says, “The amount of peak rainfall the city receives also needs to be taken into account. For instance, Delhi receives
25mm rainfall in a span of 15 minutes, so the drain size calculation is done accordingly. This process is called standardisation and unfortunately, the city of Delhi
lacks any kind of standardisation in planning its drainage system." This monsoon season in particular saw more than average amount of rainfall, causing the level of the Yamuna to rise beyond the danger level. As a result city
officials had to shut the gates of all the major drains to avoid the city from getting flooded. This, however, only aggravated the water logging condition, as the
drains began overflowing, and the ongoing construction had choked them completely. |
||||||||||||||
What needs to be done |
||||||||||||||
| “Extra storm water that runs off from parks and rooftops can be channelized so that rain water can be harvested. This also alleviates the problem of decline in
ground water levels,” says Sushmita. “In fact, for the very first time a plan has been proposed to tap storm water drains in Chandigarh so that it is harvested efficiently. In addition, the
process also makes sure that water from the storm water drains doesn’t get mixed with the sewage drain,” she adds. For Delhi meanwhile, authorities need to ensure that post-construction debris do not remain at the site. Similarly, poor road construction would mean more dust
and tar deposits in the drains. So, de-silting drains before the monsoons begin is crucial. |
||||||||||||||
What are the difficulties? |
||||||||||||||
|
For a city that is spread over thousands of kilometres, taking a detailed picture of the overall drainage system is a complex task. Taking stock of the
topography of the city, the levels of all natural and man-made drains and links between sewer and storm drains underground requires a thorough survey which could take
months at a stretch. The fact that storm water drains also carry sewage makes the task more difficult. It is definitely an uphill task. And taking care of the enormous piles of debris caused by pre-CWG games construction would be a start. Mumbai saw unparalleled
devastation caused by the monsoons in July 2006, which eventually led to a massive revamp of the city’s underground drainage plans. The city is now much more equipped
to handle an overflow.
So it is not too late for Delhi, yet. |
||||||||||||||
