Why Karachi will keep flooding

Pakistan’s port city Karachi, one of the world’s largest cities, faces frequent floods due to rampant construction on flood plains, blocked drains and destruction of mangroves

There was a time just 50 years ago when it scarcely rained in Karachi, Pakistan’s industrial and commercial hub and seaport; just a shower every few years if residents were lucky. From the late 70s, however, rains are more frequent as are floods in the sprawling 1,400 square mile city of 21 million people, one of the world’s biggest in terms of both area and population.

Traffic stalls with roads being waterlogged and there’s serious risk of falling into open manholes and drowning. The flood may be localised when it rains in only part of Karachi, but it nonetheless disrupts the lives and livelihoods of thousands of people.

Is global warming responsible?

“Global warming exists. That’s obvious by all the changes we see and experience — consensus only varies as to its extent,” said internationally acclaimed architect, urban planner and environmentalist Arif Hasan, who is a leading authority on Karachi.

He does not find the increased frequency of rains extraordinary. “Looking at the rainfall figures, I can say with certainty that the present floods have nothing to do with climate change. Not even minor. The figures keep going up and down. There is no regular pattern. We’ve had periods of far more intense flooding during the devastation of 2010. It rained frequently during the 70s. Karachi’s Lyari river frequently overflowed previously, but the city didn’t drown.”

Then why does it drown now?

“Major outlets to the sea were blocked,” he explained. A bypass, for instance, was built at the junction of two major natural drainage channels to replace the flood plains. It was a narrow and inadequate 60-feet-wide drain flowing into a creek leading directly to the sea. During the rains, it can’t cope with the volume. This is in the Clifton area, adjacent to the Defence Housing Authority, home to many of the city’s most affluent who seek to live as close as possible to the ocean. As a result, the upscale residential area now dominates the city’s coastal area, covering almost 14 square miles and growing relentlessly. The problem is that most of Karachi’s wastewater and sewage is channelled into the sea, so there’s no avoiding cutting through DHA to get there.

“Another major drainage channel flows into a similar creek (Gizri creek). Its one-and-a-half kilometre wide floodplain was replaced by an 80 feet drain!  The area never flooded before; now it does. Why? Because DHA converted the floodplain into a residential area. When rains occur during high tide, the water can’t get out because the tide pushes back the rainwater into the drain, blocking it from exiting,” Hasan added.

Other contributing factors are scores of encroachments in the form of ‘katchi abadis’, or informal settlements. When it rains heavily, many of these are inundated because they are built on floodplains. The most recent case is of Saadi town which was completely submerged last year and all but disappeared.

An unsatisfactory sewerage system compounds Karachi’s woes. Existing sewage processing plants have only one-fourth the capacity to treat what Karachi generates. “These could process more of Karachi’s sewage — if it only reached those plants! Their capacity is 150 million gallons, but only 30 million reaches. The rest, about 400 million gallons, goes into the sea.”

Stormwater drains double as outlets for sewage which mixes with city floodwaters, creating serious health hazards.

“The city simply has to get rid of the Defence housing colony that’s encroached on a mangrove strip and the Mai Kolachi Bypass road (in Clifton)… There’s no other way,” Hasan said.

Public protests led by environmentalists have failed to save the mangroves. The once vast mangrove forests have been progressively shrinking. The resultant heavy pollution has threatened shrimp nurseries and the livelihoods of local fishing communities.

“The whole area now stinks, and there’s no mechanism to get the sewage properly flushed out,” said Noman Ahmed, head of the department of architecture, NED University. Eventually, the smell may drive residents away.

“People who reside there or are thinking of moving into DHA reclaimed area should think twice,” warned Noman, “DHA Phase 8 alone is about 4,000 acres, the bulk of it from reclamation. To do it scientifically is very expensive. Instead, quicksand and marshy areas were consolidated by simply dumping and compacting earth. That’s not good enough. In any seismic activity, cracks may appear in buildings and infrastructure with serious consequences. Yet, now they’re thinking of reclaiming even more!”

The same mistakes were made by other major cities — Bombay, Dhaka, Bangkok and, in the nineteenth century, New York, London and Paris. Drainage channels were closed and canals and creeks built over them. “But the big difference between those western cities and us is that those were small populations, making it easier to correct,” Hasan said. “Today, Karachi is the world’s fastest growing city.”

“Planners know the problems but are unable to act on them for political reasons. Different parts of Karachi are controlled by various ethnic groups and political parties that don’t see eye-to-eye. Karachi comes under 13 different administrations that don’t coordinate with each other — Cantonment Boards, Port Trust, Civil Aviation Authority, industrial estates, housing societies, etc… Everything is done ad hoc.”

There are endless delays in implementing sanctioned plans. The financial constraints keep mounting with the steadily increasing population in the urban sprawl.

“There’s still no overall authority in Karachi to control construction… or to prevent damaging changes,” said architect and activist Roland deSouza.

Misbahuddin Farid, former head of the Karachi Water & Sewerage Board (KWSB), agreed. “Nobody even considers KWSB a stakeholder, so we’re not even consulted. I’ve brought up the matter often, even with the chief minister, to no avail.”

Surely things have come to a head by now?

“It’s a political problem, not a planning one,” said Hasan, “City government planners are highly qualified and know all this. The biggest problem is that politicians are not aware and don’t inform themselves. It is ignorance and the lack of desire to know. They don’t see it because it doesn’t happen to them. The planners, the best informed, have no independence. If they assert themselves, they can be sacked or transferred to doing nothing of consequence. So they keep quiet to retain their jobs or leave for jobs elsewhere.”

“In the coming 50, 100 years, global warming may cause greater rainfall and aggravate matters. But whether there’s global warming or not, unless these problems are resolved, Karachi will keep flooding.”

Ironically, Karachi also suffers chronic water shortage, a problem that impacts the entire country. Pakistan, overall, is getting more water than ever before, from both increasing floods and rains. “Yet our water storage can hardly meet a month of our needs,” said ecologist and energy expert Parvaiz Naim. His key concern, he stressed, was that the “lack of adequate water storage facilities exposes us to floods when we get more rains, and droughts when we get less. Pakistan needs to go for adaptation measures.”