Dhaka drainage struggles to deal with unusual rain levels

Even the areas of Dhaka with a well equipped sewerage system that usually do not get waterlogged due to rain were inundated yesterday as rainfall exceeded normal levels.

The sewerage infrastructure of Dhaka is equipped to handle only about half the amount of rainfall than what the city witnessed yesterday, leaving transportation stranded and the roads inundated.

Different VIP roads in the city, areas in Dhanmondi and Kazi Nazrul Islam Avenue are a few examples of roads which were completely waterlogged yesterday. Other areas of the city suffered more.

“The sewerage system can easily cope with about 20-30mm of rain. But yesterday the rain was of an unusually high 60mm. That’s why the roads were waterlogged,” an official of Wasa told The Daily Star.

The drainage system of most areas of the city is faulty, with land grabbers virtually clogging up the city’s drainage channels.

Currently more than a dozen authority bodies are in charge of the drainage system of Dhaka. Water Supply & Sewerage Authority (Wasa) handle only a fraction of this.

The two city corporations together deal with 1800 km of drainage. Wasa covers around 20 percent of the drainage system. Even with so many bodies involved, portions of the city remain out of proper drainage coverage.

On top of that, due to the river water levels being already high due to the rainy season, the water from the roads did not flow out into the drains as it normally would, said the Wasa official.

When asked if our drainage system is adequate, the Wasa official said that with normal levels of rain, the sewerage system works fine. With rain levels like that of yesterday, it will take some time as the water has to be pumped out.

Many areas of the city get inundated due to low levels of rainfall due to the blockage of surface drains with trash. It is the duty of the city corporations maintain the surface drains according to the Wasa official.