Karachi’s existing network of drains had limited capacity and absorbed around 50 per cent of the rainwater under normal circumstances. The meeting was told that excess water was not absorbed by the system, causing urban flooding.

One year after the worst floods in the history of Independent Pakistan, Pakistan President Asif Ali Zardari on Monday directed the Sindh government to prioritize a comprehensive plan to prevent urban flooding in Karachi by adopting a sustainable, long-term strategy based on international best practices for managing sewage and stormwater.

The President was speaking at a meeting on saving Karachi from urban flooding and environmental degradation and promoting sustainable water resource development.

This followed a comprehensive presentation by international water and sewage management experts who proposed various solutions to address the challenges of urban flooding and sewage in Karachi on the pattern of the tunnel sewer systems of Washington DC, the London Super Sewer Project, and the Deep Tunnel Sewerage System of Singapore.

The experts informed that Karachi generated almost 450 million gallons per day (MGD) of sewage. They added that sewage and stormwater were collected in small and large open drains which fell into the Lyari and Malir rivers and were released untreated into the sea, polluting the marine ecosystem.

During the briefing, it was proposed that a network of small and large sewer tunnels under existing roads in high-flood zones of Karachi may be developed. It was highlighted that underground tunnelling using modern techniques would not disturb the public, city traffic and land ownership.

Further, the experts said that Karachi’s existing network of drains had limited capacity and absorbed around 50 per cent of the rainwater under normal circumstances. The meeting was told that excess water was not absorbed by the system, causing urban flooding. This would be challenged in the face of a changing climate, they said.

Hyderabad also facing floods

Speaking on the occasion, President Zardari underlined the need for completing the feasibility study to control flooding in Karachi through tunnelling options within three months. He stated that Karachi and its coastal areas need to be made clean and brought at par with other metropolitan cities of the world.

He said that since the proposed project would have significant environmental impacts, therefore, the government of Sindh should approach international donors to seek environmental financing for the project.

He also appreciated the experts’ advice that the construction of the wastewater treatment system would also help supply treated water to Balochistan for agriculture, besides promoting the fisheries sector.

The President remarked that the city of Hyderabad was also facing urban flooding and sewage issues that also needed to be addressed on priority.

The 2023 Pakistan floods occurred from March to July of 2023, caused by monsoon rains which returned to Pakistan after nine months after the 2022 Pakistan floods. Floods worsened at the end of June due to upcoming monsoon rains. At least 159 people were killed, including many children.