Why Karachi Floods
Governments are quick to blame devastating floods on climate change. But many of the reasons for these floods are to do with what governments have not done. Here, Arif Hasan reviews the many reasons why disastrous floods are taking place in Karachi and what is needed for this to change.
Before 27th August this monsoon season the volume of rainfall was far less than on many previous occasions. Yet, streets were turned into rivers, cars and homes were washed away, and over thirty persons drowned or were electrocuted. However, on 27 August Karachi received the highest quantity of rainfall in one day after 92 years which washed out entire settlements. This has raised two questions one, how is it that despite a lower volume of rainfall, Karachi has been devastated? And two, did the heavy rainfall on August 27 have anything to do with climate change.
The vast increase in population and the lack of investment in sewers: Karachi’s storm water drains are two seasonal rivers, the Lyari and the Malir. Both rise in the foothills of the Kirthar range and run parallel to each other with a distance of between 14-20 kms in between. Fifty-eight storm water drains (or nalas) carry the water of their catchment areas to them and over six-hundred smaller drains feed into these nalas.
Before independence in 1947, Karachi’s population was only 450,000; now it is over 15 million. The city had a sewage system mostly consisting of underground earthenware pipes and sewage was treated through biological treatment at gutter baghicha (gutter garden). The treated effluent was used for growing vegetables, flowers for religious ceremonies, and fruit trees. The gutter garden covered an area of just over 1,000 acres (404.7 hectares).
With Partition and the arrival of about 800,000 migrants from India and the rest of Pakistan between 1947 and 1951, the city was forced to expand and both formal and informal sector developments took place far away from the gutter garden. The Greater Karachi Resettlement Plan of 1958 created two satellite towns some twenty kilometers from Karachi. Sewage treatment plants were planned for but never constructed and their sewage flowed (and still flows) into the sea and/or the nalas.
Informal settlements and informal drains: Because of a lack of resources for housing, informal settlements developed along the nalas that discharge their sewage into the nalas. After the mid-‘60s formal sector developments also used nalas for disposal. And as a result, sludge from sewage began to clog the nalas and their tributaries. In 1978-79, there were very heavy rains in Karachi and much of the housing along the nalas was washed away.
After that, informal settlement residents started to informally purchase solid waste from the municipal authorities to compact it along the nala edges to secure them and to provide land for their homes. As a result, nala widths decreased substantially from twenty to forty meters to less than ten meters and at some places even four to five meters. (add but a much lower flood water capacity?)
The deterioration of the nalas: Karachi is spatially a large city and has only two landfill sites over 40 kms from the eastern edge of the city. Due to the high time and monetary cost of using these, garbage increasingly did not reach the landfill sites. Meanwhile, a recycling industry mostly in the informal sector, developed. Contractors pay the KMC officials not to pick up the garbage so that the recyclable material can be picked from it. The non-recyclable material is then thrown into the nalas or at various informal dumping sites along the natural drainage systems. By the mid-‘90s, most of the nalas of the city were full of compacted solid waste. And to this day on some of them children play cricket and football on them.
Building over the nalas: With the lack of implementation of Karachi’s development plans and the pressure for space for commercial activity, the local government constructed bazaars over the nalas. Meanwhile, the government of Sindh has constructed car parking facilities, offices, and hostels on the nalas, and even part of the registry of the Supreme Court of Pakistan.
As the space for the disposal of solid waste in nalas reduced over time, solid waste was and is still used for reclaiming land from the sea for both low income and elite housing. Informal developers informally arrange for KMC trucks to deposit their solid waste on the mangrove marshes and hire KMC tractors to compact it.
A major part of Phase 8 of Karachi’s most elite settlement, the Defense Society has been reclaimed from the Sea through the use of municipal solid waste. In addition, two of Karachi’s major outlets to the sea have been considerably reduced by developing housing for high income groups and a highway. As a result, it has become difficult for water to flow out into the sea especially during high tides.
Storm water drains: To overcome these problems, the government of Sindh (Karachi Water and Sewerage Board and Local Government) in the ‘80s and ‘90s arranged for the rehabilitation of the old sewage treatment plants and the construction of new ones along with the building of trunk sewers along the main roads. However, these trunks remain dry because the sewage continues to flow in the storm water drains.
The Orangi Pilot Project Research and Training Institute that had long been supporting communities to develop lane sewers decided to document the storm water drains and discovered that the only manner in which this problem could be tackled was to clean and cover the drains and subsequently and incrementally build trunks along the nalas. This concept was accepted by the State and is being partially implemented..
Real estate development: But now, another issue surfaced. In the hilly formations north of the city, massive real estate development is taking place. Much of this development has demolished the geological formations that contained natural drainage channels and water collection depressions. As a result, when it rains, areas south of this region are completely submerged by flood waters. With more developments taking place, the likelihood of flooding increasing will also increase.
Then there are also serious institutional issues. The central and provincial governments are controlled by different political parties. They are at constant loggerheads which has made it impossible for Karachi’s infrastructure related problems to be tackled rationally and with sufficient finances. It has also made it impossible to develop a decentralized form of city government free from direct provincial control.
In desperation to maintain its vote bank, the federal government brought in the National Disaster Management Authority to de-silt Karachi’s nalas. So far they have removed 30,000_tonnes of solid waste from 42 choking points on 3 nalas. However, desilting will once again make the edges of the nalas vulnerable to erosion and will lead to the destruction of an unspecified number of homes. As it is for the widening of just one major nala the removal of 5782 houses will be required. If the proposal for widening all the nalas to their original width is followed then the number of affected houses will in the neighborhood of 60,000. So far, a concept for the rehabilitation plan has not been developed although the government has promised rehabilitation.
To tackle these issues, a long term plan for Karachi will be required that is in keeping with the finances that are available or can be generated. However, this cannot be done without an empowered local government and without the participation of the people who live along the nalas. OPP-RTI’s interaction with the local communities living along the nalas found only they knew the points of maximum flooding, the behavior pattern of the floods, and of various smaller drains that had disappeared. So far, how they can be made part of the planning and rehabilitation process has not been considered by the government agencies. In addition, climate change only adds to the urgency of addressing the issues raised above.
Published in the Daily Dawn on the 6th of September, 2020.
