PAKISTAN : AFTER the recent rains which wreaked havoc in Karachi an architect proposed that a  flood path should be carried out to prevent flooding in Karachi.

I am of the opinion that studies won't solve the flooding problem, rather practical measures are needed.

The reason that many areas in Karachi are still inundated even 10 days after rainfall is simple. The city does not have a proper drainage system. Wherever a system exists, the 'invert' levels of pipes or drains were never maintained properly. As a result the storm water at the furthest upstream end cannot flow down to the final outfall point, unhindered.

The important point is that no major city in the world has drains for storm water; instead they have pipes or tunnels. Drains become a disposal area for solid waste. One can witness the phenomenon everywhere in Karachi.

WHY is it that Bangkok which receives much more rainfall than Karachi, the storm water is drained in a matter of minutes? The reason is simple.

Bangkok has flood protection measures like polder system, dikes, pumping stations, drainage tunnels and pipes, retention area and a flood control centre.

The city's drainage system has been designed for rainfall intensity 60 millimetres per hour. There are  1,682 canals of 2,600 km length, pipe systems constitute 6,400 km length,  main roads have drainage pipes of 1,640 km, and secondary roads have 4,760 km of pipes.

Pumping stations exist of at 409 places with total pumping capacity of 1,638 cubic meters per second.

That is not all.

Bangkok has seven giant tunnels of five meters each [16.5 feet] in diameter. The Don Mueang tunnel has a diameter of six meters [20 feet]. This has increased the drainage capacity from 95 to 240 cubic metres a second.

The city has 25 storm water retention ponds, with total volume of 13 million cubic meters.

In a bold innovation, Bangkok has an 11 acre park at Chulalongkora University, which can hold up to one million gallons of water. During the rainy season, the park collects and stores water which is used for irrigation in the dry season.

NO WONDER Karachi is flooded after the every heavy rainfall.

The World Students Society thanks the author. 


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