Karachi’s Mehmoodabad drain before the cleaning work started this year. — Courtesy: Karachi Municipal Corporation

Early downpour exposes Karachi’s drainage flaws

Due to a clogged, ineffective drainage system, even a short shower brings great misery to residents.
Updated 03 Aug, 2020 06:28pm

For Mushir Ahmed, this time of the year gets so busy that he does not know when the "day ends and night begins". As a member of the Karachi Municipal Corporation (KMC) for over two decades, just before the monsoon rains each year, he leads a team of about 60 people who launch into action ahead of the downpour. The team brings out heavy machinery — excavators, dumpers, tractor-trolleys and even wheelbarrows and shovels — to go around the city in order to unclog the nearly four dozen overburdened storm water drains or nallahs. Each year, when it rains, the channels can dispose of the excess water to the Arabian Sea.

This year, however, he admitted that the municipality is almost three months late on the task. To make matters worse, the rains came early.

"Of the 44 drains, three at Gujjar, Orangi and Mehmoodabad which are 12 km, 10 km and 8 km long respectively, are the most problematic," said Ahmed, director of municipal services. "It can take up to a month to clean each nallah."

These natural drains are part of the network of 550 big and small storm water drains which criss-cross the sprawling metropolis. Unfortunately, even with a few millimetres of rain, the city quickly turns into a bathtub.

This year, the rain began on Monday, July 7 and lasted for a couple of hours with a maximum of 43 mm recorded in Saddar to just 1.2mm in Surjani Town, in two different parts of the city. But the mayhem it caused, from roads getting submerged, sewage spewing out of manholes, power outages in most parts of Karachi to people stuck in hours of traffic jams on main arteries resulted in an outburst of anger on social media.

The scenes on television screens were all too familiar. A ragtag army of sanitation workers with brooms, pails and bamboo poles tried to poke at the mouths of drains and manholes, as commuters inched their way and bikers waded waist-deep to drag their lifeless vehicles along.

The downpour is accompanied by tragedy. From 2014 to 2019, there have been over 70 rain-related deaths in Karachi alone; 2018 was an exception, but that was because there was hardly any rain.

On Monday, six deaths were reported in Karachi.

"Even 50 mm to 70 mm of rainfall under an hour triggers urban flooding in Karachi," Sardar Sarfaraz, the Pakistan Meteorological Department’s Karachi head, told The Third Pole.

Dredging the drains

All these months, the Sindh government had been working on a plan which it is optimistic about. The authorities claimed to have found a solution to minimising the damage due to urban flooding this year.

The Local Government department, the Sindh Solid Waste Management Board (SSWMB), the KMC and the six district municipal corporations have joined forces under a US$100 million World Bank project to do things differently, said Zubair Channa, who oversees the Solid Waste Emergency and Efficiency Project (Sweep) project, under the World Bank- funded Competitive and Liveable city of Karachi (Click) of which he is the programme director.

Using the existing human resources that worked every year to clean the drains, this time, he said, the government is ensuring the sewage (usually piled on the side of the drains), does not slide back into the drain but reaches its last resting place — at a 10-acre plot of land at the 500-acre Jam Chakro landfill site, located about 30 km from Karachi’s city centre.

There is another four-acre plot in the Treatment Plant 1, in the Sindh Industrial Trading Estate (Site), where some of the sludge will be transported to and put into hundreds of mammoth 40-year-old sludge silos. "These have been cleaned and repaired and ready to put to use,” pointed out Channa. “These tanks will allow the wet sewage to settle in a compartment at the bottom and the top dry portion may be treated and used as manure."

"The work has just begun. In the last few days, we have dumped more than 100,000 cubic feet of sludge at both sites. As we pick up pace, we intend to touch one million cubic feet per day," said Channa.

Cleaning work at Karachi’s Mehmoodabad drain remains incomplete as the rains start. — Photo courtesy: Karachi Municipal Corporation
Cleaning work at Karachi’s Mehmoodabad drain remains incomplete as the rains start. — Photo courtesy: Karachi Municipal Corporation

The sludge contains anything from plastic waste to raw sewage, weeds and construction material. Ahmed often finds "sofas, mattresses, even commodes and sinks and chassis of motorbikes" while digging up the drains.

But of all these, it is the sewage by the Karachi Water and Sewerage Board that is the biggest culprit as it is causing silting of the drains, he said.

Speaking to The Third Pole on condition of anonymity, a senior KWSB officer concurred with KMC’s Ahmed that the water authority was putting the sewage in the drains which were “technically” meant to drain storm or rainwater.

However, "with no major investment made to either lay the new sewerage system or to rehabilitate the crumbling sewerage infrastructure", the water authority was compelled to deposit the city’s sewage into these drains.

With a need for "billions of rupees" to segregate the water from the sewage lines, another problem was that there is "no land corridor where the KWSB can lay or install new infrastructure", he pointed out. And where there was land, it would mean digging up roads. "Closing certain arteries to work on sewage lines would be nothing short of a nightmare," said the KWSB officer.

Bursting at the seams, the mega city with a population of 13 million is among the world’s most densely populated urban centres and generates an estimated 13,000 tonnes of garbage daily — which the SSWMB is unable to collect.

The waste authority claims it is able to pick 70% of it and take it to the two landfills. According to the SSWMB, they are able to dump 6,000 to 7,000 tonnes of Karachi’s garbage at the Jam Chakro landfill and another 1,000 to 2,000 tonnes at the second 500-acre landfill site at Gond Pass, near Hub river. The rest remains strewn around the city.

The role of urban planning

In addition to the sewage and garbage that choke the drains, it is the haphazard and illegal construction on and along the drains and the debris that is another major problem that exacerbates urban flooding.

"The real estate developments and other physical works have greatly altered the natural flow pattern of surface water that flows into the city from north and north east towards the south (sea side)," pointed out Noman Ahmed, professor and dean at the faculty of architecture and management sciences at the NED University in Karachi.

Ecologist Rafi ul Haq gave the example of urban forests along 26 km of Lyari river and another one along Malir river which would come in the way of the natural flow. "No doubt the city needs green patches, but land use planning must be carried out so there are no bottlenecks in the free flow of the water to the sea," he pointed out.

Further, said urban planner Farhan Anwar, most of the open spaces, including parks and green spaces that could have acted as "natural filtration zones" and "drainage basins", have been "encroached, paved and concretised", aggravating flooding.

But Karachi is also different in many ways from other cities of not just Pakistan but globally. An anomaly, Noman Ahmed said, the city required a "robust" but “unconventional urban” planning. With Karachi accounting for one-third of the population of Sindh, with a highly multicultural mix of people residing in it, he said this representation has never reflected at the administrative level.

"A lot of Karachi’s problems may get resolved if an informed debate on core management and development issues of the city was held," he added.

Anwar proposed "demarcation of flood risk zones" and a "vulnerability profile prepared that documented vulnerable people and assets coming within those limits". So far, only one such study was carried out for the Malir river back in 1979 after it flooded the Korangi Industrial estate after which an embankment was constructed.

But with 19 different land-owning agencies in Karachi spread across all three tiers of government, the perpetual fight for resources between local, provincial and federal authorities administering this city by the sea is far from easy.


This article was originally published by The Third Pole and has been reproduced with permission.