During July-August 2023, the People’s Republic of China (PRC) was hit by heavy rainfall and devastating floods, caused by the remnants of Typhoon Doksuri, which saw widespread destruction of many cities in the country’s northern as well as southern regions. The flooding was the result of what is considered to be the heaviest rainfall in Beijing for more than a century, which is estimated to have affected nearly five percent of the population in various provinces. Since the advent of the floods, the PRC announced a relief of a total of US$1.07 billion, which however, amounts to only one-tenth of the current total estimated losses incurred due to these floods. Interestingly, a majority of the cities affected by these floods are part of the sponge city initiative of the PRC, which are originally intended to mitigate flood-related risks as well as damages, and to boost flood resilience in major cities.

Interestingly, the institutional focus on sponge cities began with the emergence of issues related to climate change as well as unsustainability in developmental activities of the PRC in the last decade, dubbed as the Sponge City Program. The Sponge City Program was launched in response to devastating floods in Beijing in 2013, which initially included its implementation in 16 pilot cities within two years, and another 14 more cities added in the year after. The focus of the programme included mitigating issues related to (extreme) urbanisation, pollution, shortage of water, flooding, as well as other climate change-related challenges that have exacerbated the problems related to water security in the PRC.

However, these recent floods have overwhelmed these sponge cities, and have affected the lives, livelihood and infrastructure within the cities, which saw widespread heavy rainfalls and destructive flooding, which (in terms of quantity) was at least three times of the original absorption capacity of these cities. It has led to an estimated 142 deaths, numerous missing persons, and have caused huge damage to infrastructure. According to the China News Service, an official estimate of 40,000 homes were destroyed, while electricity and communication in 155,500 houses as well as other facilities were seriously damaged. However, unofficial reports of houses destroyed, and facilities affected are much higher in number than those reported through official channels. The relocation of nearly 1.75 million residents has taken place, with an estimated economic loss reportedly reaching US$13.2 billion, and counting.

There are also issues related to region-wise differentiation, amongst the northern China region, which has seen rampant water shortages on an annual basis in comparison to the southern China region, which has problems related to seasonal scarcity. Furthermore, the larger concentration of water in the southern China region accounts for 80 percent of the total water availability in the country and is predominantly due to institutional and systemic disparities related to distribution and accessibility provided. This has been further exacerbated by the problems related to flooding, heavier rainfalls and storms, especially in and around the Yangtze basin and its tributaries. This was a major reason that has been underlined for the need for creating sponge cities, which will form as a buffer to store excess rainfall and to stifle and mitigate the damages caused due to flooding in major cities. The Asian Development Bank (ADB) has provided funding to the initial projects that began in the PRC, which later became a major initiative of state funding and model for flood management and protection of major cities.

Interestingly, the concept of sponge cities as a new urban construction model for flood management and ecological infrastructure was proposed by Chinese researchers in the early 2000s, which was aimed to alleviate urban flooding, water resource shortages, and the urban heat island effect. Professor Kongjian Yu of Peking University, an ecological urban planner and landscape architect was amongst the earliest proponents of the concept, who obtained his doctorate from the Harvard’s Graduate School of Design, and was opposed to the traditional idea of constructing dams for flood management. He took inspiration from international integrated urban water management (IUWM) strategies, and focused on creating “flexible spaces for water to spread out and seep underground, both to prevent flooding and to be stored for later use”. The IUWM strategies aims to target and control urban flooding, water pollution and to effectively recycle rainwater, which however entailed the provincial administrations to focus on the creation of sponge cities to absorb excess rainwater and mitigate the challenges of flood-related disasters. The main features of sponge cities include being ‘environmentally adaptive’, ‘systematic and comprehensive’ and ‘environmentally friendly’. The concept is inspired by ancient Chinese agricultural approaches to water management, such as rice terraces and natural wetlands acting as sponges to retain water during flooding and recharge water during drought.

The Sponge City Program was also implemented to mitigate the demand for water in the PRC that has vastly increased mainly due to the huge stress on water sources in Chinese cities and became an important institutional design for mitigating flood- related challenges. In 2022, about one-tenth of the existing Chinese cities created legislations to implement sponge city guidelines. Furthermore, the sponge cities in the PRC are estimated to process around 70 percent of the rainwater across 80 percent of their land by 2030, and will have innovative water management strategies, such as constructing stormwater parks that collect, cleanse, and store stormwater while also providing recreational spaces, protecting natural habitats, as well as protecting infrastructure and investment in major cities. However, there are some challenges as well. Major cities as well as sponge cities in the PRC remain vulnerable to the destructive effects of the floods and are not able to provide the required protection and support it was originally intended to provide. Furthermore, it has created challenges for food security, largely stifling the initiatives by the Chinese administration to improve and increase food production, affecting storage and hindering distribution among the citizens.

The sponge city model has gained international attention and has been adopted in other countries facing climate change and flood-related challenges as well. The success of sponge cities lies in their integration of green (including forests, floodplains, wetlands etc), and gray infrastructure (including dams, seawalls, roads, pipes or water treatment plants), combining natural solutions like wetlands with traditional infrastructure like drainage systems. Overall, sponge cities in PRC are an innovative approach to urban planning that aims to address flooding and improve ecological resilience. They mimic natural water absorption, drainage, storage and related-management processes, though the recently emerging challenges from climate change provide many roadblocks and vulnerabilities that require a very transformative and comprehensive approach to succeed.

(Author is Assistant Professor of Politics, Department of International Studies, Political Science and History, Christ (Deemed to be University), India. Email: [email protected] Views expressed in the article are personal to the author, and do not necessarily reflect the views of AICIS. AICIS is neither responsible nor liable for the accuracy, completeness, suitability, or validity of any information in the article.)

References
 

1. Associated Press (AP). (2023). Severe floods in China’s northern province killed29 and caused tens of billions of economic losses.
https://apnews.com/article/china-floods-hebei-typhoon-doksuri-losses-deaths-e08749ca94aa220f7130821547340f1f

2. Campbell, M. (2022). What are sponge cities and could they solve China’s water crisis?.
https://www.euronews.com/green/2022/10/22/china-s-sponge-cities-are-a-revolutionary-rethink-to-prevent-flooding#:~:text='Sponge%20cities'%20are%20trying%20to%20solve%20the%20water%20crisis&text=This%20means%20roofs%20are%20covered,to%20keep%20floods%20at%20bay.

3. Chen, J. (2021). Key considerations for mobilising financing for Sponge Cities.
http://growgreenproject.eu/wp-content/uploads/2021/07/ADB-Mobilising-financing-for-sponge-cities.pdf

4. Conservation International. (2023). Green-Gray Infrastructure.
https://www.conservation.org/projects/green-gray-infrastructure#:~:text=Green%20infrastructure%20refers%20to%20natural,pipes%20or%20water%20treatment%20plants.

5. Faith Ka Shun Chan, Wendy Y. Chen, Zilin Wang, Christine Loh, Dimple R. Thadani, Gordon Mitchell, Patrick Y.K. Chau, Monica A. Altamirano, Begonia Arellano Jaimerena, Yunfei Qi, Lei Li, Xinbing Gu, Fang Zhang. (2022). Meeting financial challenge facing China's Sponge City Program (SCP) – Hong Kong as a gateway to green finance. Nature-Based Solutions, Vol. 2, Dec 2022, 100019.
https://doi.org/10.1016/j.nbsj.2022.100019

6. Li, H., Ding, L., Ren, M., Li, C. & Wang, H. (2017). Sponge City Construction in China: A Survey of the Challenges and Opportunities. Water, Vol. 9(9), 594.

7. Oates, L., Dai, L., Sudmant, A., & Gouldson, A. (2020). Building Climate Resilience and Water Security in Cities: Lessons from the Sponge City of Wuhan, China. Coalition for Urban Transitions.
https://urbantransitions.global/wp- content/uploads/2020/03/Building-climate-resilience-and-water-security-in-cities- lessons-from-the-Sponge-City-of-Wuhan-China-final.pdf

8. Rau, S. (2021). Sponge Cities in the People’s Republic of China – Evolution of ADB Support.
https://events.development.asia/system/files/materials/2021/07/202107-sponge-cities-people-s-republic-china-evolution-adb-support.pdf

9. Rau, S. (2022). Sponge Cities: Integrating Green and Gray Infrastructure to Build Climate Change Resilience in the People’s Republic of China. ADB Briefs.
https://www.adb.org/sites/default/files/publication/838386/adb-brief-222-sponge-cities-prc.pdf

10. Reuters. (2023). What are China’s ‘sponge cities’ and why aren’t they stopping the floods?. Indian Express.
https://indianexpress.com/article/explained/explained-global/china-sponge-cities-floods-explained-8885495/

11. Stanway, D. What are China's 'sponge cities' and why aren't they stopping floods?. Reuters.
https://www.reuters.com/world/china/what-are-chinas-sponge-cities-why-arent-they-stopping-floods-2023-08-10/

12. Yeung, P. (2023). Cities are becoming more like Sponges.
https://reasonstobecheerful.world/sponge-cities-china-climate-change-resilience/#:~:text=Water%20management%20that%20prizes%20lakes,%E2%80%94%20and%20prettier%20ones%2C%20too.&text=From%20an%20airplane%2