Karachi floods because it's half shaped like a bowl: expert
Karachi floods because roughly half of it is actually shaped like a bowl, according to topography expert Prof. Jamil Kazmi of the University of Karachi.
This is why, he says, Central and West districts always flood and not just because of a weak stormwater drainage system. The topography or terrain of the city is 51% hills and mountains in the East, West and North which are surrounded by 580 feet of ranges.
This explains why Naya Nazimabad, Nagan Chowrangi, Surjani Town, Yousuf Goth, Orangi Town and adjacent areas in Central District suffered so much.
Topography experts study the natural and artificial physical features of an area.
“There has been no proper planning executed in Karachi by the authorities in recent days, as they do not much understand the terrain systems in the North and West parts of Karachi,” he added. This means that people living in low-lying areas are even more vulnerable.
Kazmi said that the rainwater does not find a way to exit and just pools in to stand in low-lying areas. It does not help that, “The people have encroached on storm water drains by building houses over there,” he added.
Kazmi talked about the houses near mountainous areas in Nusrat Bhutto Colony, Pahar Ganj and Gulistan-e-Jauhar which have been built without a proper study of the terrain. “Nature has its own impact and any construction without keeping the natural [terrain] in mind will have the same result as we saw in Karachi during the torrential rains,” he added.
Landsliding in Javed Hill View a day earlier was a sobering reminder of the perils of construction without proper soil testing.
“Topography is an imperative aspect in construction of new settlements,” he said. If we build houses in a landscape where earthquakes are predicated, then it is our own and miscalculation. Kazmi said that Bahria Town is inundated with rain water, as its construction has been done by cutting into hills and heavy rocks. “No comprehension of proper terrain was taken into consideration before the construction of Bahria Town and Naya Nazimabad,” he added.
Prof. Kazmi said that the government should plan proper bunds or embankments at the Korangi Causeway, Malir River and Hub River and build water reservoirs to store rainwater for future use. And of course, it is essential to conduct topographic surveys before anyone is allowed to construct new housing schemes.