Replacing concrete pavements with wetlands, green rooftops and rain gardens means stormwater is absorbed back into the land, making water work for the city instead of against it.

Asian cities are struggling to accommodate rapid urban migration, and development is encroaching on flood-prone areas.

Recent flooding in Mumbai was blamed in part on unregulated development of wetlands, while hastily built urban areas are being affected by flooding across India, Nepal, and Bangladesh.

This is not a trend only in developing countries; floods in Houston, United States, highlighted the risks of development in environmentally sensitive and low-lying areas. In 2012, a severe flood in Beijing wreaked havoc on the city's transportation systems, and in 2016 floods overwhelmed drainage systems in Wuhan, Nanjing, and Tianjin.

A sponge city refers to sustainable urban development including flood control, water conservation, water quality improvement and natural eco-system protection. It envisions a city with a water system which operates like a sponge to absorb, store, infiltrate and purify rainwater and release it for reuse when needed. The sponge city program takes inspiration from the low impact development (LID) and green infrastructure in the US and Canada, sustainable drainage systems (SusDrain) in the UK and other European countries, and water sensitive urban design (WSUD) in Australia and New Zealand. It promotes natural and semi-natural measures in managing urban stormwater and wastewater as well as other water cycles.

The primary goals of sponge city construction are: retaining 70–90% of average annual rain water onsite by applying the green infrastructure concept and using LID measures, eliminating water logging and preventing urban flooding, improving urban water quality, mitigating impacts on natural ecosystems, and alleviating urban heat island impacts. The sponge city program will also create investment opportunities in infrastructure upgrading, engineering products and new green technologies.

Engineering solutions are popular interventions, but cities cannot simply pipe away flood risks.

To address the issue, China's sponge city initiative has an ambitious goal: by 2020, 80% of urban areas should absorb and re-use at least 70% of rainwater.

China's "sponge city initiative" aims to arrest this cycle through the use of permeable surfaces and green infrastructures.

However, the initiative faces two challenges: lack of expertise of local governments to effectively coordinate and integrate such a complex set of activities, and financial constraints.

Launched in 2015 in 16 cities, the initiative seeks to reduce the intensity of rainwater runoff by enhancing and distributing absorption capacities more evenly across targeted areas. The resulting groundwater replenishment increases availability of water for various uses. This approach not only reduces flooding but also enhances water supply security.