sponge city

File:Biking through flash flood in Foshan.jpg]]

Urbanization encourages the construction of grey infrastructure in cities. Excessive use and development of grey infrastructure can lead to water shortages, pollution, and overall degradation of water ecosystem services. Current urban architectural planning also creates a large number of buildings, simultaneously limiting cities' green space, drainage, and rainwater collection ability. Consequently, rainfall cannot meet modern cities' water requirements and causes cities lots of problems regarding water ecology and aquatic environments.{{Cite journal |last1=Yu |first1=K. J. |last2=Li |first2=D. H. |last3=Yuan |first3=H. |last4=Fu |first4=W. |last5=Qiao |first5=Q. |last6=Wang |first6=S. S. |date=2015 |title='Sponge City': Theory and practice |url=http://www.planning.org.cn/files/ff/39.%E2%80%9C%E6%B5%B7%E7%BB%B5%E5%9F%8E%E5%B8%82%E2%80%9D%E7%90%86%E8%AE%BA%E4%B8%8E%E5%AE%9E%E8%B7%B5_%E4%BF%9E%E5%AD%94%E5%9D%9A%EF%BC%9B%E6%9D%8E%E8%BF%AA%E5%8D%8E%EF%BC%9B%E8%A2%81%E5%BC%98%EF%BC%9B%E5%82%85%E5%BE%AE%EF%BC%9B%E4%B9%94%E9%9D%92%EF%BC%9B%E7%8E%8B%E6%80%9D%E6%80%9D.pdf |journal=City Planning Review |volume=39 |issue=6 |pages=26–36 |doi= |access-date=2020-12-15}}

Meanwhile, high-intensity artificial constructions, such as buildings, roads, and public squares, lead to the lower pad's excessive hardening, changing the original natural foundation and hydrological characteristics. Because of this, surface flow increases from 10% to 60%, while infiltration is drastically reduced, even to zero.{{Cite book |last=Wu |first=Ye Gang |title=Sponge City Design: Concept, Technology & Case Study. |publisher=Phoenix Science Press |year=2016 |location=Jiangsu}} According to an investigation that the Ministry of Housing and Urban‑Rural Development conducted in 2010, 62% of 351 cities across the country faced flooding between 2008 and 2010; 137 cities flooded more than three times during this time period. This frequent urban flooding makes more and more people recognize the importance of water ecosystems and urban ecological infrastructure. The simple concept of fast discharge, a traditional gray water management model, is no longer helpful in addressing the rainwater dilemma during rapid urbanization. To cope with such extensive urban water issues, China is increasingly attaching importance to urban flood management and water ecological-system services and vigorously promoting the idea of Sponge City.{{cn|date=March 2025}}

The People's Republic of China adopted the Sponge City initiative, largely motivated by the failure of the conventional grey infrastructure of flood control and stormwater management systems, due to the persistent efforts by Chinese ecological urbanists through letters and proposals sent to high level Chinese authorities since early 2000.{{Cite book |last=Yu |first=Kongian |title=Letters to the Leaders of China: Kongjian Yu and the Future of the Chinese City |quote=with contributions by Michael Sorkin, Peter Rowe, Thomas. J. Campanella, A. Weiwei, Z. Lin, X. Ren, P.G. Rowe, M. Sorkin, D. Sui, J. Sze, and K. Yu |publisher=Terreform |year=2018 |isbn=978-0-9960041-8-3 |location=New York |pages=54, 111, 124–126}}{{Cite web |last=Yu |first=Kongjian |year=2012 |title=ASLA Award of Excellence: A Green Sponge for A Water Resilient City |url=https://www.asla.org/2012awards/026.html |work=American Society of Landscape Architects }}{{Cite web|last=俞孔坚及团队的海绵城市理论与实践|title=Kongjian Yu and Sponge City Theory and Practice with His Team|url=https://www.turenscape.com/topic/spongecity/index.html}}{{Cite web|title=土人设计网 - 北京土人城市规划设计股份有限公司 (城市设计、建筑设计、环境设计、城市与区域规划、风景旅游地规划、城市与区域生态基础设施规划) |trans-title=Turen Design Network - Beijing Turen Urban Planning and Design Co., Ltd. (urban design, architectural design, environmental design, urban and regional planning, scenic tourism destination planning, urban and regional ecological infrastructure planning) |url=https://www.turenscape.com/en/home/index.html|access-date=2 January 2022 |website=www.turenscape.com}} Though the concept had been published and practiced since early 2000, it was the Beijing flood on July 21, 2012 which caused 79 deaths that prompted the top Chinese authorities to accept the Sponge City concept and make it a nationwide policy.{{Cite journal |last1=Hermaputi |first1=Roosmayri Lovina |first2=Chen |last2=Hua |date=27 February 2017|title=Creating Urban Water Resilience: Review of China's Development Strategies " Sponge City " Concept and Practices |url=https://www.academia.edu/32423905 |journal=The Indonesian Journal of Planning and Development |volume=2 |issue=1 |pages=1–10 |doi=10.14710/ijpd.2.1.1-10|doi-access=free }}{{Cite journal |last=Gies |first=Erica |title=The architect making friends with flooding |url=https://www.technologyreview.com/2021/12/21/1041318/flooding-landscape-architecture-yu-kongjian/ |journal=MIT Technology Review|language=en |access-date=10 March 2022}}

In 2015, China initiated a pilot initiative in 16 districts.{{Cite news|url=https://www.theguardian.com/sustainable-business/2015/oct/01/china-sponge-cities-los-angeles-water-urban-design-drought-floods-urbanisation-rooftop-gardens|title=China's sponge cities: soaking up water to reduce flood risks|last=Harris|first=Mark|date=1 October 2015 |work=The Guardian |access-date=24 August 2019 |language=en-GB |issn=0261-3077}}{{Cite web |url=https://simplicable.com/new/sponge-city|title=What is a Sponge City?|website=Simplicable|access-date=24 August 2019 }}{{Cite web |url=http://theconversation.com/chinas-sponge-cities-aim-to-re-use-70-of-rainwater-heres-how-83327|title=China's 'sponge cities' aim to re-use 70% of rainwater – here's how |last1=Biswas|first1=Asit K. |last2=Hartley |first2=Kris |work=The Conversation |date=5 September 2017 |language=en|access-date=24 August 2019}} In the years following, additional pilot district/cities were selected to continue implementing sponge city design. Four batches were selected by 2017, consisting of a total of 87 cities. The timeline for the sponge city pilot projects were as follows:{{Cite journal |last=Griffiths |first=James |last2=Chan |first2=Faith Ka Shun |last3=Shao |first3=Michelle |last4=Zhu |first4=Fangfang |last5=Higgitt |first5=David Laurence |date=2020-02-17 |title=Interpretation and application of Sponge City guidelines in China |url=https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0222 |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |volume=378 |issue=2168 |pages=20190222 |doi=10.1098/rsta.2019.0222 |pmc=7061963 |pmid=32063173}}

• 2015-2018: Implement sponge city design with small-scale urban pilot projects
• 2018-2020: Publish Sponge City standards, management, and monitoring
• Recycle 70% of rainfall
• 2020-2030: Complete integration of Sponge Cities

The country plans for 80 percent of its urban cities to harvest and reuse 70 percent of rainwater. Building sponge cities does not necessarily require large investments. But such a fact has been widely misunderstood due to misleading media and the fact that the "sponge city" has been more than often misused by local government and contractors, as well as unprofessional designers as a fashionable brand and slogan which has actually nothing to do with this nature based solution.{{Cite web |last=Green|first=Jared |date=4 August 2021 |title=Kongjian Yu Defends His Sponge City Campaign|url=https://dirt.asla.org/2021/08/04/kongjian-yu-defends-his-sponge-city-campaign |website=The Dirt}}{{Cite news |date=11 September 2021 |title=Readers write: Defending 'sponge cities' after Zhengzhou floods |work=Christian Science Monitor |url=https://www.csmonitor.com/Commentary/Readers-Respond/2021/0911/Readers-write-Defending-sponge-cities-after-Zhengzhou-floods|access-date=30 December 2021 |issn=0882-7729}} The major obstacles of implementing the nature-based sponge city are the business-as-usual mentality of grey infrastructure engineering, ornamental gardening and conventional urban planning, as well as the code systems that have been established to defend these obsolete urbanism practices.{{Cite web |date=28 May 2020 |title=Meet the Architect Whose Revolutionary "Sponge Cities" are Helping Combat Climate Change |url=https://radiichina.com/sponge-cities-architect-yu-kongjian/ |access-date=30 December 2021 |work=RADII {{!}} Stories from the center of China's youth culture|language=en-US}} Funding sponge cities has also been a challenge.{{Cite news|url=https://www.theguardian.com/sustainable-business/2015/oct/01/china-sponge-cities-los-angeles-water-urban-design-drought-floods-urbanisation-rooftop-gardens |title=China's sponge cities: soaking up water to reduce flood risks|last=Harris|first=Mark|date=1 October 2015 |work=The Guardian |access-date=25 August 2019 |language=en-GB |issn=0261-3077}}{{Cite web |url=https://www.hydro-int.com/en/sponge-cities-0 |title=Sponge Cities |last=simoncox |date=31 May 2016 |work=Hydro International |language=en |access-date=25 August 2019 |archive-date=22 July 2021 |archive-url=https://web.archive.org/web/20210722081023/https://www.hydro-int.com/en/sponge-cities-0 |url-status=dead }}

After achieving success in China, the sponge city model has attracted over-exposed climate zones such as Dhaka and Kenya, as well as major cities like Berlin and Los Angeles.{{Cite web |last=Kazi Khaleed Ashraf|date=14 December 2020 |title=Imagining a Dhaka for 2035 |url=https://www.thedailystar.net/in-focus/news/imagining-dhaka-2035-2010777|work=The Daily Star}}{{Cite web |title=Should Los Angeles Transform Itself Into a Sponge City? |date=27 January 2016|url=https://ahbelab.com/2016/01/27/should-los-angeles-transform-itself-into-a-sponge-city/}}{{Cite web |title=Berlin & China Creating "Sponge Cities" — Landscape Architects Help Cities Absorb Water, Cool Down |date=4 December 2017 |url=https://cleantechnica.com/2017/12/04/berlin-reusing/}}{{Cite web |date=5 March 2019 |title="Sponge cities": between Myth and Reality |url=https://leonard.vinci.com/en/sponge-cities-between-myth-and-reality/ }}

File:Wuhan Optics Valley Modern Tram (4).jpg was built using green track, which reduces surface run-off and provides other environmental benefits.]]

The Sponge City philosophy is to distribute and retain water at its source, slow down water as it flows away from its source, clean water naturally, and adapt to water at the sink when water accumulates. This is in stark contrast to the conventional solution of grey infrastructure, which is to centralize and accumulate water using big reservoirs, speed up the flow by pipes and channelized drains, and fight against water at the end by higher and stronger flood walls and dams.{{Cite web |date=29 November 2021 |title=China's sponge city concept |url=https://www.thiscityknows.com/chinas-sponge-city-concept/}}{{Cite journal |last=Yu |first=Kongjian |date=2017 |title=Green Infrastructure through the Revival of Ancient Wisdom |url=https://www.amacad.org/news/green-infrastructure-through-revival-ancient-wisdom |journal=American Academy of Arts and Sciences Bulletin |volume=Summer 2017, Vol. LXX, No.4 |pages=35–39}} The theory of Sponge City emphasizes the basic principles of 'based on nature', 'source control', 'local adaption', protecting nature, learning from nature, preserving urban ecological space as much as possible, restoring biodiversity, and creating a beautiful landscape environment. All of this can be realized by achieving natural absorption, natural infiltration, and natural purification.{{Cite book |last=俞孔坚 |url=https://www.amazon.com/%E6%B5%B7%E7%BB%B5%E5%9F%8E%E5%B8%82-%E7%90%86%E8%AE%BA%E4%B8%8E%E5%AE%9E%E8%B7%B5%EF%BC%88%E4%B8%8A%E3%80%81%E4%B8%8B%E5%86%8C%EF%BC%89-%E4%BF%9E%E5%AD%94%E5%9D%9A/dp/B01JHVGQ3W |title=海绵城市——理论与实践（上、下册） |publisher=中国建筑工业出版社 |year=2016 |isbn=9787112194896 |location=北京}} These principles come from long-standing wisdom and strategies practiced across China for thousands of years, when water had to be worked with and around instead of combatted with gray infrastructure. The infiltration effects of the natural ecological background (such as topography and landforms), the purification effect of vegetation and wetlands on water quality, and the combination of natural and artificial means allow the city to absorb and release rainwater. Urban green spaces and urban bodies of water —constructed wetlands, rain gardens, green roofs, recessed green spaces, grass ditches, and ecological parks—are the central "sponge bodies."{{Cite web |title=土人设计网 - 北京土人城市规划设计股份有限公司 (城市设计、建筑设计、环境设计、城市与区域规划、风景旅游地规划、城市与区域生态基础设施规划) |url=https://www.turenscape.com/en/home/index.html |access-date=2021-12-28 |website=www.turenscape.com}}

There are three main facets to developing such systems: protecting the original urban ecosystem, ecological restoration, and low-impact development.

• Protection focuses on the city's original ecologically sensitive areas, such as rivers, lakes, and ditches. Natural vegetation, soil, and microorganisms are used to gradually treat the aquatic environment and restore the damaged urban ecosystem.
• Restoration measures include identifying ecological patches, constructing ecological corridors, strengthening the connections between the patches, forming a network, and delineating the blue and green lines to restore the aquatic ecological environment.
• Mandatory measures apply to urban roads, urban green spaces, urban water systems, residential areas, and specific buildings to protect ecological patches, maintain their storage capacity, strengthen source control, and form ecological sponges of different scales.{{Cite journal |last=仇 |first=保兴 |date=2015 |title=海绵城市(LID)的内涵、途径与展望 |url=http://gb.oversea.cnki.net/KCMS/detail/detail.aspx?filename=KCSJ201507018&dbcode=CJFD&dbname=CJFD2015 |url-status=dead |journal=中国勘察设计 |issue=7 |pages=30–41 |issn=1006-9607 |archive-url=https://web.archive.org/web/20210722081012/http://gb.oversea.cnki.net/KCMS/detail/detail.aspx?filename=KCSJ201507018&dbcode=CJFD&dbname=CJFD2015 |archive-date=2021-07-22 |access-date=2020-12-15}}

With these design principles in mind, they can be applied at three different levels/scales:

• Macro-scale: regional or watershed level for regional master plans
• Meso Scale: planning at city, township, village level
• Micro scale: individual "sponge units" within meso scale. Examples include parks and neighborhoods

Sponge city policies have been more frequently implemented in new construction than in retrofitted developments from the past few decades of rapid urbanization. Xiamen's Yangfang residential area and Shanghai's Langang Park are two new developments indicative of this trend.{{Cite web |date=7 July 2020 |title=Xiamen: Adapting to Climate Change with Sponge City Construction – Sino-German Cooperation on Climate Change, Environment, and Natural Resources |url=https://climatecooperation.cn/urbanisation/xiamen-adapting-to-climate-change-with-sponge-city-construction/ |access-date=2021-12-07 |language=en-US}}{{Cite web |last=李雯蕊 |title='Sponge city' |url=https://global.chinadaily.com.cn/a/202110/29/WS617b41bca310cdd39bc71fea.html |access-date=2021-12-08 |website=global.chinadaily.com.cn}} Shougang park, the former site of a steel mill which was redeveloped into a park which includes the 2022 Winter Olympics venue Big Air Shougang, incorporates sponge city design concepts.{{Cite book |last=Hu |first=Richard |title=Reinventing the Chinese City |date=2023 |publisher=Columbia University Press |isbn=978-0-231-21101-7 |location=New York}}{{Rp|page=49–51}}

In his speech at the Urbanization Work Conference on December 12, 2013, CCP general secretary Xi Jinping said "When upgrading the urban drainage system, priority should be given to retaining limited rainwater and using the power of nature to drain water. Build a sponge city with natural retention, natural penetration, and natural purification."{{Cite web|title=中国为什么要建设"海绵城市"？--时政--人民网|url=http://politics.people.com.cn/n1/2019/1020/c429373-31409450.html |access-date=15 December 2020 |website=politics.people.com.cn}}{{Cite book |last=Yu |first=Kongjian |title=Sponge City and the Practice of Turenscape, in: deCoding Asian Urbanism |publisher=A+D Museum at Los Angeles, and the Lakshmi Mittal and Family South Asia Institute at Harvard University |year=2021 |isbn=978-1-85946-9651|pages=196–215|language=English}}{{Cite journal |last=Yu|first=Kongjian |date=November 2021 |title=The Sponge City: Planning, Design and Political Design |url=https://www.ajlajournal.org/articles/the-sponge-city-planning-design-and-political-design |journal=African Journal of Landscape Architecture |volume=2}} To this end, in October 2014, the Ministry of Housing and Urban-Rural Development issued "Technical Guidelines for Sponge City Construction", emphasizing the importance of the top-level design of urban rainwater management, as well as planning to guide urban construction with ecological priority as the basic principle.{{cn|date=March 2025}}

In August 2015, the "Sponge City Construction Performance Evaluation Method" clarified requirements for the use of central fiscal funds and provided guidelines for the construction effectiveness of pilot demonstration cities. According to the guidelines and related standards and specifications, the China Building Standard Design and Research Institute has initially established a "sponge city construction standard design system", including newly built, expanded, and rebuilt sponge buildings and communities, roads and squares, parks, green spaces, and urban water systems.{{cn|date=March 2025}}

The General Office of the State Council Guideline to promote building sponge cities (Guobanfa [2015] No. 75) pointed out that the construction of sponge cities occurs through strengthening the management of urban planning and construction, giving full play to the impact of buildings, roads, green spaces, and water systems on rainwater. Under the guideline, cities in China will collect and utilize 70 percent of the rainwater, with 20 percent of urban areas meeting the target by 2020, and the proportion will increase to 80 percent by 2030.{{Cite web |title=Guideline to promote building sponge cities |url=http://english.www.gov.cn/policies/latest_releases/2015/10/16/content_281475212984264.htm |archive-url=https://web.archive.org/web/20191106185207/http://english.www.gov.cn/policies/latest_releases/2015/10/16/content_281475212984264.htm |url-status=dead |archive-date=November 6, 2019 |access-date=15 December 2020 |work=State Council, People's Republic of China }}

In 2015 and 2016, pilot projects for sponge cities were organized with the support of national policies. Sixteen cities, including Zhenjiang, Jiaxing, and Xiamen, were selected as the first batch of pilot cities, and 14 cities, including Shenzhen, Shanghai, Tianjin, and Beijing, were selected as the second batch of pilot cities to carry out the construction of sponge cities in an orderly manner. In addition, the Central Ministry of Finance introduced a public-private partnership (PPP) model to increase financial policy support.

However, this set-up may threaten local government's ability to fund these programs, which are estimated to require $230 billion by 2030 in order to meet their goals.{{Cite journal|last1=Griffiths|first1=James|last2=Chan|first2=Faith Ka Shun|last3=Shao|first3=Michelle|last4=Zhu|first4=Fangfang|last5=Higgitt|first5=David Laurence|date=3 April 2020 |title=Interpretation and application of Sponge City guidelines in China |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences|volume=378|issue=2168|pages=20190222|doi=10.1098/rsta.2019.0222|pmc=7061963|pmid=32063173|bibcode=2020RSPTA.37890222G}} The national government is only planning to subsidize one-fifth of the costs of implementing Sponge City policies, and the flooding of over half of pilot cities – such as Ningbo – since the program started has the potential to worry private investors.

China's central government mandates that by 2030, 80% of China's urban space must include sponge city adaptations and must recycle at least 70% of rainfall.{{Cite book |last1=Curtis |first1=Simon |title=The Belt and Road City: Geopolitics, Urbanization, and China's Search for a New International Order |last2=Klaus |first2=Ian |publisher=Yale University Press |isbn=9780300266900 |location=New Haven and London |publication-date=2024 |pages=173 |doi=10.2307/jj.11589102 |jstor=jj.11589102}}

Sixteen cities in China were chosen in 2015 for the first batch of pilot projects. Cities are listed below:

• Baicheng{{Cite journal|last1=Wang|first1=Sisi|last2=Palazzo|first2=Elisa|date=1 May 2021 |title=Sponge City and social equity: Impact assessment of urban stormwater management in Baicheng City, China|url=https://www.sciencedirect.com/science/article/pii/S2212095521000596|journal=Urban Climate|language=en|volume=37|pages=100829|doi=10.1016/j.uclim.2021.100829|bibcode=2021UrbCl..3700829W |s2cid=234845468|issn=2212-0955|url-access=subscription}}
• Qian’an{{Cite web|title=North China city Qian'an makes efforts in "sponge city construction" - Xinhua {{!}} English.news.cn|url=http://www.xinhuanet.com/english/2021-08/03/c_1310104995_3.htm|access-date=8 December 2021 |website=www.xinhuanet.com}}
• Jinan{{Cite web |title=Expressing a Regional Identity through China's Sponge City Initiative |first1= Yi-Ting |last1=Chou |first2=Anthony |last2=Fettes |url=https://www.sasaki.com/voices/expressing-identity-through-chinas-sponge-city-initiative/ |access-date=8 December 2021 |website=Sasaki|language=en}}
• Hebi{{Citation needed|date=December 2021}}
• Xixian New Area{{Cite journal|last1=Li|first1=Jiake|last2=Ma|first2=Menghua|last3=Li|first3=Yajiao|last4=Deng|first4=Chenning|last5=Pan|first5=Baozhu|date=16 January 2020 |title=Evaluating Hydrological and Environmental Effects for Low-Impact Development of a Sponge City|url=http://www.pjoes.com/Evaluating-Hydrological-and-Environmental-nEffects-for-Low-Impact-Development-nof,109308,0,2.html|journal=Polish Journal of Environmental Studies|language=english|volume=29|issue=2|pages=1205–1218|doi=10.15244/pjoes/109308|s2cid=209727178|issn=1230-1485|doi-access=free|bibcode=2020PJES...29.1205L }}
• Zhenjiang{{Cite web|date=15 May 2017 |title=Zhenjiang Sponge City Infrastructure Planning|url=https://www.herrerainc.com/projects/zhenjiang-sponge-city-infrastructure-planning/|access-date=8 December 2021 |website=Herrera |language=en-US}}
• Jiaxing
• Chizhou
• Wuhan{{Cite web|title=Wuhan Sponge City|url=https://www.arcadis.com/en-us/projects/asia/china/wuhan-sponge-city|access-date=8 December 2021 |website=www.arcadis.com|language=en-US}}{{Cite web|last=Wuhan|first=Li Jing in|date=23 January 2019 |title=Inside China's leading 'sponge city': Wuhan's war with water|url=http://www.theguardian.com/cities/2019/jan/23/inside-chinas-leading-sponge-city-wuhans-war-with-water|access-date=8 December 2021 |work=The Guardian|language=en}}
• Changde{{Cite web |title=Changde, China |url=https://www.urbanlab.com/yangming-archipelago|access-date=8 December 2021 |website=UrbanLab|language=en-US}}
• Chongqing{{Cite web|title='Sponge cities' absorb China's flooding woes|url=https://www.chinadailyhk.com/article/147148#%E2%80%98Sponge-cities%E2%80%99-absorb-China%E2%80%99s-flooding-woes|access-date=8 December 2021 |website=China Daily hk}}
• Suining
• Gui’an New Area{{Cite journal |last1=Qi|first1=Yunfei|last2=Chan|first2=Faith Ka Shun|last3=O'Donnell|first3=Emily C.|last4=Feng|first4=Meili|last5=Sang|first5=Yanfang|last6=Thorne|first6=Colin R.|last7=Griffiths|first7=James|last8=Liu|first8=Lingyun|last9=Liu|first9=Sitong|last10=Zhang|first10=Chunqian|last11=Li|first11=Lei |year=2021|title=Exploring the Development of the Sponge City Program (SCP): The Case of Gui'an New District, Southwest China |journal=Frontiers in Water|volume=3|pages=41|doi=10.3389/frwa.2021.676965|issn=2624-9375|doi-access=free|bibcode=2021FrWat...3.6965Q }}
• Nanning{{Cite web|title=Across China: "Sponge city" program bears fruit - Xinhua {{!}} English.news.cn|url=http://www.xinhuanet.com/english/2020-10/12/c_139435158.htm|access-date=8 December 2021 |website=www.xinhuanet.com}}
• Pingxiang{{Cite web|title=Xinhua Headlines: Pingxiang, the making of a Chinese "sponge city" - Xinhua {{!}} English.news.cn|url=http://www.xinhuanet.com/english/2019-08/01/c_138275668.htm|archive-url=https://web.archive.org/web/20190801133003/http://www.xinhuanet.com/english/2019-08/01/c_138275668.htm|url-status=dead|archive-date=August 1, 2019|access-date=8 December 2021 |website=www.xinhuanet.com}}
• Xiamen{{Cite web|title=Xiamen: Adapting to Climate Change with Sponge City Construction – Sino-German Cooperation on Climate Change, Environment, and Natural Resources|date=7 July 2020 |url=https://climatecooperation.cn/urbanisation/xiamen-adapting-to-climate-change-with-sponge-city-construction/|access-date=8 December 2021 |language=en-US}}

In 2016, a second batch of fifteen cities were chosen for pilot projects. Cities are listed below:

• Beijing{{Cite journal|last1=Zhang|first1=Shuhan|last2=Li|first2=Yongkun|last3=Ma|first3=Meihong|last4=Song|first4=Ting|last5=Song|first5=Ruining|date=August 2018|title=Storm Water Management and Flood Control in Sponge City Construction of Beijing|journal=Water|language=en|volume=10|issue=8|pages=1040|doi=10.3390/w10081040|doi-access=free|bibcode=2018Water..10.1040Z }}
• Tianjin
• Dalian{{Cite journal|title=Sponge City Planning of Dalian based on Functional Division of Natural Ecological Environment|url=http://www.ekolojidergisi.com/download/sponge-city-planning-of-dalian-based-on-functional-division-of-natural-ecological-environment-5999.pdf|journal=Ekoloji}}
• Qingyang
• Guyuan{{Cite journal|last1=Jia|first1=Lu|last2=Xu|first2=Guoce|last3=Huang|first3=Miansong|last4=Li|first4=Zhanbin|last5=Li|first5=Peng|last6=Zhang|first6=Zhenxi|last7=Wang|first7=Bin|last8=Zhang|first8=Yixin|last9=Zhang|first9=Jiaxin|last10=Cheng|first10=Yuting |year=2020|title=Effects of Sponge City Development on Soil Moisture and Water Quality in a Typical City in the Loess Plateau in China|journal=Frontiers in Earth Science|volume=8|pages=125|doi=10.3389/feart.2020.00125|bibcode=2020FrEaS...8..125J|issn=2296-6463|doi-access=free}}
• Xining
• Shanghai{{Cite web|date=28 December 2017 |title=China's 'sponge cities' are turning streets green to combat flooding|url=http://www.theguardian.com/world/2017/dec/28/chinas-sponge-cities-are-turning-streets-green-to-combat-flooding|access-date=8 December 2021 |work=The Guardian|language=en}}
• Ningbo{{Cite web |date=16 March 2020 |title=Is the Sponge City Program (SCP) transforming Chinese cities?|url=https://blogs.nottingham.ac.uk/bluegreenfutures/2020/03/16/is-the-sponge-city-program-scp-transforming-chinese-cities/|access-date=8 December 2021 |website=Blue-Green Futures|language=en-US}}
• Fuzhou
• Shenzhen{{Cite web|title=Shenzhen|url=https://iwa-network.org/city/shenzhen/|access-date=8 December 2021 |website=International Water Association|language=en}}{{Cite thesis|title=Decoding Sponge City in Shenzhen : resilience program or growth policy?|url=https://dspace.mit.edu/handle/1721.1/111261|publisher=Massachusetts Institute of Technology |year=2017|degree=Thesis|first=Hongru|last=Cai|hdl=1721.1/111261}}
• Zhuhai{{Cite journal|last1=Fu|first1=Yang|last2=Zhang|first2=Xiaoling|date=1 November 2018 |title=Two faces of an eco-city? Sustainability transition and territorial rescaling of a new town in Zhuhai |url=https://www.sciencedirect.com/science/article/pii/S0264837717313960|journal=Land Use Policy|language=en|volume=78|pages=627–636|doi=10.1016/j.landusepol.2018.06.007|bibcode=2018LUPol..78..627F |s2cid=158405949|issn=0264-8377|url-access=subscription}}
• Yuxi
• Sanya{{Cite web|title=土人设计网 - 北京土人城市规划设计股份有限公司 (城市设计、建筑设计、环境设计、城市与区域规划、风景旅游地规划、城市与区域生态基础设施规划)|url=https://www.turenscape.com/en/project/detail/4700.html|access-date=8 December 2021 |website=www.turenscape.com}}

Sponge Cities have been shown to achieve the following:

• recharge ground water{{Cite journal |last=Zhang |first=Cheng |last2=Tang |first2=Xiaolan |last3=Dai |first3=Liyuan |last4=Zhang |first4=Peng |last5=Chi |first5=Yixia |date=2020 |title=Application of Sponge Urban Design Concept in River Watercourse Landscape Renovation |url=https://www.jstor.org/stable/48639812 |journal=Journal of Coastal Research |pages=590–595 |issn=0749-0208}}
• adapt to disaster/change
• environmental restoration
• less reliance on municipal pipelines
• improve ecology of city
• water purification through plants
• prevention of sewer overflow
• reduce stormwater runoff{{Cite journal |last=Wang |first=Jin |last2=Zhou |first2=Lingling |last3=Han |first3=Ping |last4=Li |first4=Guangxue |date=2020 |title=The Impact of Urbanization and LID Technology on Hydrological Effect |url=https://www.jstor.org/stable/48640876 |journal=Journal of Coastal Research |pages=14–22 |issn=0749-0208}}
• flood mitigation
• provide ecosystem services Yu, K., Li, D., Yuan, H., Fu, W., Qiao, Q., & Wang, S. (2015). Sponge City: Theory and Practice. City Planning Review, 39(6), 26–36.

• Interconnection/communication between cities

Studies have shown that sponge cities are highly effective in reducing stormwater runoff and improving water quality.{{Cite journal |last=Wang |first=Jin |last2=Zhou |first2=Lingling |last3=Han |first3=Ping |last4=Li |first4=Guangxue |date=2020 |title=The Impact of Urbanization and LID Technology on Hydrological Effect |url=https://www.jstor.org/stable/48640876 |journal=Journal of Coastal Research |pages=14–22 |issn=0749-0208}} The effectiveness of sponge cities has been evaluated through modeling or through observation as monitoring data is not widely available.{{Cite journal |last=Yao |first=Yichen |last2=Hu |first2=Caihong |last3=Liu |first3=Chengshuai |last4=Yang |first4=Fan |last5=Ma |first5=Bingyan |last6=Wu |first6=Qiang |last7=Li |first7=Xinan |last8=Soomro |first8=Shan-e-hyder |date=2022 |title=Comprehensive performance evaluation of stormwater management measures for sponge city construction: A case study in Gui'an New District, China |url=https://doi.org/10.1111/jfr3.12834 |journal=Journal of Flood Risk Management |language=en |volume=15 |issue=4 |pages=e12834 |doi=10.1111/jfr3.12834 |issn=1753-318X|doi-access=free }} {{Cite journal |last=Kongjian |first=Y. U. |last2=Dong |first2=Wang |date=2023-02-15 |title=Modular Approach Creating Low-Maintenance Sponge City: Benjakitti Forest Park in Bangkok, Thailand |url=https://journal.hep.com.cn/laf/EN/10.15302/J-LAF-0-040003 |journal=Landscape Architecture Frontiers |language=en |volume=11 |issue=1 |pages=72–85 |doi=10.15302/J-LAF-0-040003 |issn=2096-336X}}Monitoring data has been difficult to obtain due to the lack of monitoring data and evaluation standards published by the government.{{Cite book |last=Gies |first=Erica |title=Water always wins: thriving in an age of drought and deluge |date=2022 |publisher=The University of Chicago Press |isbn=978-0-226-71960-3 |location=Chicago, IL}}

Currently, flood mitigation impacts are often local instead of city-wide due to local-scale projects and planning.{{Cite journal |last=Griffiths |first=James |last2=Chan |first2=Faith Ka Shun |last3=Shao |first3=Michelle |last4=Zhu |first4=Fangfang |last5=Higgitt |first5=David Laurence |date=2020-02-17 |title=Interpretation and application of Sponge City guidelines in China |url=https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0222 |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |volume=378 |issue=2168 |pages=20190222 |doi=10.1098/rsta.2019.0222 |pmc=7061963 |pmid=32063173}} Nineteen of the thirty pilot cities has experienced flooding since implementation. {{Cite journal |last=Griffiths |first=James |last2=Chan |first2=Faith Ka Shun |last3=Shao |first3=Michelle |last4=Zhu |first4=Fangfang |last5=Higgitt |first5=David Laurence |date=2020-02-17 |title=Interpretation and application of Sponge City guidelines in China |url=https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0222 |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |volume=378 |issue=2168 |pages=20190222 |doi=10.1098/rsta.2019.0222 |pmc=7061963 |pmid=32063173}} However, local areas within cities that were retrofitted with the sponge city concept in mind have experienced little to no flooding in response to big storms.

Benjakitti Forest Park is located in downtown Bangkok, Thailand. The plot of land was previously a brownfield as a result of a tobacco factory. The area experienced subsidence and flooding due to urbanization. The 52.7 square hectometers of land was developed by Turenscape into a public green space in 2023, designed with 187,500 cubic meters of stormwater storage capacity. This storage prepares for a 10-year rainfall event, proving effective in 2022. Much of Bangkok flooded, but the park and surrounding area did not. In addition to rainwater management, the park includes: sponge wetlands, a recreational boardwalk system, an amphitheater designed to be safe to flood, warehouses for sports and museums, and ecological environments for flora and fauna. {{Cite web |title=Benjakitti Forest Park: Transforming a Brown Field into an Urban Nature {{!}} ASLA 2024 Professional Awards |url=https://www.asla.org/2024awards/9526.html |access-date=2025-06-02 |website=www.asla.org}} The project was created with low budget ($20 USD per square meter) and low maintenance in mind.

The Luotian River, with a length of about 8 kilometers, has adopted an ecological control method to regulate stormwater. As a part of the Luotian Water Comprehensive Regulation Project, the river channel was widened to restore the riparian areas and existing reservoirs were expanded to become storage lakes for rainfall. Rainfall was also used as a water supply instead of bypass to the river. Data revealed that the sponge city design allowed water quality to increase and flooding to decrease. The natural connectivity of the river required communication and planning between cities along the river to be successful.{{Cite journal |last=Zhang |first=Cheng |last2=Tang |first2=Xiaolan |last3=Dai |first3=Liyuan |last4=Zhang |first4=Peng |last5=Chi |first5=Yixia |date=2020 |title=Application of Sponge Urban Design Concept in River Watercourse Landscape Renovation |url=https://www.jstor.org/stable/48639812 |journal=Journal of Coastal Research |pages=590–595 |issn=0749-0208}}

One of the pilot cities, the Gui-an New District was established in 2014. $1 billion USD was invested into sponge city design, with an emphasis on pervious paving, as well as 70 monitoring stations. However, as of 2022, much of the sponge city design is undeveloped, including the monitoring stations. Pervious concrete has been laid down but often not maintained. {{Citation |last=Oakes |first=Tim |title=From Creation City to Infrastructural Urbanism: The Chinese National New Area as an Infrastructure Space |date=2022 |work=Infrastructure and the Remaking of Asia |pages=157–177 |editor-last=Hirsh |editor-first=Max |url=https://www.jstor.org/stable/jj.12900784.12 |access-date=2025-06-02 |publisher=University of Hawai'i Press |isbn=978-0-8248-9292-0 |editor2-last=Mostowlansky |editor2-first=Till}} Modeling revealed that flooding risk is lowered but is not entirely eradicated from sponge city design thus far. Flood mitigation success is determined by the intensity of the rainfall event.

Sanya City is a pilot city that was a part of the second batch of pilot cities. On an island, the city has experienced flooding and habitat degradation. A mangrove park and wetland park were established to mitigate this impacts and restore the ecological environment.

A 10 hectare site on the bank of Linchun River was restored into a mangrove to help with flood resilience. Urbanization allowed concrete flood walls to be built to prevent flooding, degrading the mangrove habitat in the process. The area was made into a mangrove park by restoring riparian habitats. An interlocking finger design (ecotones) was used for the land to reduce the force of ocean tides and storm surges, preventing damage to mangroves. Terraces from the city streets to the river elevation was implemented with bio-swales to catch and filter runoff. Three years after construction, ecological restoration and flood mitigation has been successful. The mangrove is still healthy and growing as a result of the flood mitigation and water quality improvements, attracting biodiversity and ecotourism. {{Cite web |title=Deep Form of Designed Nature: Sanya Mangrove Park {{!}} ASLA 2020 Professional Awards |url=https://www.asla.org/2020awards/178.html |access-date=2025-06-02 |website=www.asla.org}}{{Cite web |title=The Sponge City: Planning, Design and Political Design {{!}} AJLA |url=https://www.ajlajournal.org/articles/the-sponge-city-planning-design-and-political-design |access-date=2025-06-02 |website=www.ajlajournal.org}}

Located in downtown Sanya, the 68-hectare park was previously polluted with illegally dumping and overgrown with invasive species. {{Cite web |title=Turenscape - Sanya Dong’an Wetland Park |url=https://www.turenscape.com/en/project/detail/4719.html |access-date=2025-06-02 |website=www.turenscape.com |language=en}} Pond-and-dike systems were established to catch water and filter runoff. A forested wetland was established in the middle of the park, with recreational areas at the edges. The wetland is designed to store 830,000 cubic meters of stormwater, which will reduce flood risk. Surrounding communities have experienced less urban flooding and polluted runoff. The park has attracted biodiversity and recreation to the area.

• Green infrastructure for stormwater management/Low-impact development (North America)
• Nature-based solutions (European Union)
• Water-sensitive urban design (Australia)

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Category:Hydrology and urban planning

Category:Rainwater harvesting

Category:Irrigation

Category:Water in China

Category:Urban planning in China

Category:Sustainable urban planning