Written by: Ayesha Shoukat
Posted on: June 17, 2025 | 
| Chinese
Qunli Regenwasserpark, China, a successful example of the Sponge City model.
Every monsoon in Karachi is like a time bomb that is waiting to be exploded because the city has difficulty dealing with climate change and rapid urbanization. Streets are transformed into rivers, areas become islands and lifelong infrastructure collapses under the flood of infinite rain. Under this chaos, the city planners and environmentalists are looking for answers to this disorder to the east, China Ponge City Model. Can the largest city of Pakistan, which are plagued by complex governance, scarce resources and unorganized development, a natural -based approach to resistance of floods?
The Chinese sponge city initiative was introduced in 2015 to transform the urban areas into permeable and water -absorbing ecosystems. The concept is very simple, but a real revolution: Imitating natural hydrology by involving green roofs, porous sites, rainergartens and wetlands to limit the surface outflows and limit floods.
Many Chinese cities have made immense progress in this regard, especially Shanghai, Wuhan and Kunshan. Shanghai founded rainwater parks, which also serve leisure time, while Kunshan invested heavily in the permeable infrastructure and reduced the floods by a whopping 90%. Even dense megacity have recorded these elements in their urban material, restored the green cover, manage rainwater on site and increase the biological diversity.
Starry Sky, Shanghai's largest sponge park
However, the success in the sponge model in China was a bit mixed. Despite enormous investments, Zhengzhou, a pilot sponge town, was heavily flooded in 2021. This underlined a critical lesson: sponge infrastructure should not have other additional strategies for water management such as emergency provision, strong sewage systems and air -conditioning designs.
It is worth noting that Karachi's challenges reflect those of the pre-sponge cities in China. In the past three decades, urbanization has quickly broken down green spaces, blocked the natural drainage flow and replaced permeable land with concrete. In the city, illegal settlements near Nullahs, clogged drains and a weak waste management have increased the susceptibility of the city for floods.
Such systemic gaps in Karachi were exposed to the devastating monsoon times in 2020 and 2022. Whole districts were flooded and paralyzed life and business for several days. In view of the prediction of climate models that predict more intensive rainfall in the future, Karachis's susceptibility to security is no longer a seasonal fiasco, but public security and an environmental disaster.
A central Karachi road after strong monsoon rain caused chaos in Pakistan.
The Sponge City model has offered a glimmer of hope, the idea of implementing China's blueprint in Karachi is not so easy. The city has many structural and socio -economic barriers:
1. Restrictions on space
The populated urban growth in Karachi is characterized by a strong lack of space for large areas of the green infrastructure. While China's planned developments offer more opportunities for large wetlands or rainwater parks, the informal settlements and trade zones of Karachi offer very few such opportunities. Nevertheless, the small solutions, the pocket parks, the green roofs and the vertical gardens could still play a role.
2. Fragmented government and financing
China's success reflected top-down planning, political coherence and an enormous state investment. On the other hand, Karachi is plagued by the division into jurisdiction among urban, provincial and federal authorities. Institutions such as the Karachi Water & Sewerage Board faces financial tribes that make long -term investments in the green infrastructure.
A visual comparison of Shanghai and Karachi shows how Karachi can use localized, natural -based sponge city principles in order to build up the resilience of the floods.
3 .. public awareness and participation
The commitment of the community is necessary to bloom natural -based solutions. In cities such as Hong Kong, green walls and roof gardens with the help of incentive plans and campaigns to sensitize the public. In Karachi, where the public's trust in the government is low and the awareness of environmental solutions is limited, the commitment of the community will be a challenge.
4. Maintenance culture
Karachi's drainage systems are often neglected, with nullahs being blocked by garbage and silt. Measures in connection with the Sponge City model such as rain gardens and permeable branches require regular maintenance in order to remain effective. Without a more comprehensive change, a cultural and institutional commitment to maintenance in the city, new interventions risk the same cycle of neglect.
Water preparation and public space in Wadi Hanifa. (Source, Riyadh Development Authority)
Karachi does not have to reinvent the bike despite all the challenges. Examples such as Riads Wadi Hanifa restoration show worldwide how degraded watercourses can be revived by combining nature technology, wastewater treatment and native vegetation. A gradual outline and a local approach may have the greatest influence on Karachi:
- Retrofit the existing nullahs in environmentally friendly green corridors with permeable embankments, gardens and community actions.
- Get green building regulations for the new development, which must include rainwater harvest, permeable paving stones and roof gardens.
- Piloting interventions at neighborhood levels in these endangered areas such as Orangi Town or in the Malir basin to prove the concept.
- Advocate awareness campaigns that combine environmental measures with public health, security and economic resistance.
The sponge city model is not a uniform solution. But it is a very strong framework to reinterpret cities as a living, breathing ecosystems. Karachi's existing flood strategy, which is characterized by unplanned cleaning initiatives, emergency words, etc., is not withstanding the warning planet. Instead, the city has to shift from a purely economic perspective towards a more systemic, ecological understanding that combines the green infrastructure with urban planning. This requires political commitment, public-private partnerships and continuous commitment to the community. It also means that the fact that nature can not save a city from the climate crisis, although nature alone is concrete, cannot be part of the solution.
Schematic drawing of the concept “Sponge City”. (Source, department for drainage services, sustainability report 2016–2017)
Karachi may never like Shanghai or Kunshan, but it can use the principles of the sponge city that are used in these Chinese cities. The city combines localized and managed interventions with intelligent reform policy and infrastructural investments and can become a more fluid resilient city.
We should act now. Every year of inactivity, a monsoon time brings us closer to the tip of inconvenience in disasters. The problem is not whether Karachi can pay her way to the sponge city. It's about whether it can afford not to do this.