APROPOS the article titled ‘Weak structures’ (Sept 16). The writer — a seasoned academic — states that stagnant water is a common cause for the weakening of an already fragile structure. The sewerage and storm water draining infrastructure in Karachi is depleted and grossly undersised, it will be a while before it is finally upgraded.
I would recommend to the provincial government and city administration authorities to explore the possibility of sinking hundreds of tube wells in Karachi to lower the level of ground water.
The Water and Sanitation Agency in Lahore has around 600 tube wells in and around the city, which is probably the reason that while rain inundates Lahore the water drains quickly. The tube wells that are sunk in Karachi and other cities of Sindh can be solar powered to provide double benefit. Such technology is already being used across Pakistan.
A typical tube well can take the water table down within a one-mile radius and this technique was used effectively by the Salinity Control & Reclamation Programme Pakistan (SCARP) in the 1960s to convert barren water logged lands into cultivatable fields. The tube wells can be installed in low lying areas with the discharge water piped into the Malir and Lyari rivers or directly into the sea. Furthermore, since the water will be pulled out from minus 50 feet there will be no need for its treatment.
S. Nayyar Iqbal Raza
THE removal of stagnant rainwater in Karachi requires novel ideas. While engine-driven pumps are carried from location to location, they are not helping the way planners want.
How about sinking tube wells just the way it was done in the 1960s to get rid of salinity and water logging? They say one tube well can effectively pull the water table down from one mile radius.
With solar-powered tube wells easily available across Pakistan they can do wonders. If we strike freshwater, it will be a bonus. Even brackish water can be used to wash roads, just like in the past.
Published in Dawn, September 20th, 2020