Jakarta: In March 2025, Jakarta, the capital of Indonesia, faced severe flooding following torrential rains that resulted in the deaths of at least nine people and displaced 90,000 residents. This event resurrected painful memories of the 2020 floods that claimed 60 lives. Social media platforms were inundated with videos showing emergency personnel rescuing people in boats and clearing flooded roads using firetrucks.
According to Global Voices, Southeast Asia has been witnessing extreme weather events with increasing frequency and intensity, a trend attributed to climate change. This has worsened the chronic urban flooding in many megacities due to outdated urban planning and geographical challenges. In response, China introduced the concept of "sponge cities" in 2013, aiming to tackle urban flooding by enhancing cities' rainwater absorption capacities.
The sponge city model, proposed by prominent urban architect Yu Kongjian, focuses on absorbing rainwater and slowly releasing it, rather than quickly draining it away. By restoring natural water systems, such as rivers and wetlands, sponge cities mitigate flooding and promote local rainwater reuse. Yu argues that traditional methods relying on engineered drainage infrastructure are insufficient, emphasizing the need to adapt to nature.
The concept has shown promise in Southeast Asia. For instance, in Bangkok, the transformation of a former tobacco factory site into Benjakitti Forest Park demonstrated the effectiveness of this approach. During a 10-year rainfall event in 2022, the park remained unflooded while much of the city experienced inundation.
However, challenges remain. Critics of sponge cities argue that the concept is often limited to small-scale implementations, without significant city-wide impacts. Scaling up requires strong political will and cross-departmental collaboration. Additionally, the sponge city model faces limitations during extreme weather events, necessitating comprehensive drainage systems and disaster preparedness plans.
In Jakarta, high development costs and space constraints hinder the adoption of sponge city infrastructure. Nonetheless, Indonesia plans to incorporate the concept into its new capital city, Nusantara. This city, currently under construction in East Kalimantan, aims to be the world's most sustainable city, featuring large open spaces and porous surfaces for rainwater retention. However, budget cuts and concerns about project completion timelines cast a shadow over its development.