Water Resources Engineering (WRE) connects to economic, environmental, and societal issues. Our student Eoin Rapp makes this connection in Shenzhen, China. This current event was reported in Elevate, on, December 12th, 2018, under the title, “Shenzhen as China’s Pioneer “Sponge City”: Dialogue with The Nature Conservancy,” by Gloria Luo. This is unlikely to be “fake news” as China’s continued water supply and runoff problems are well documented for several years now, and such a water shortage serves as a justification for more natural systems of retaining water in cities.

The Chinese government’s Ministry of Housing and Ministry of Rural-Urban Development in partnership with local municipalities launched the Sponge Cities program almost 5 years ago. This undertaking falls under the realm of stormwater management, and it’s a part of an ambitious goal by the Chinese State Council to effectively use 70% of storm rainwater in cities. This effort to manage stormwater fulfills an essential role of water resources engineering by preventing or reducing downstream flooding (Chin, 2013). The development of these green infrastructures is important to the WRE community as it fundamentally addresses a major WRE goal of managing and controlling water runoff, and it serves and an example of using the available resources of rainwater and new technologies such as absorbent pavement in order to reach this goal of water management. While the article does provide general descriptions of green infrastructure types the specifics on the type of rainwater quality and quantity in Shenzhen as well as more concrete examples of green infrastructure were not addressed, both of which are important design factors in creating a stormwater management system.

Societal, environmental and economic issues dictate key aspects of stormwater management system sand include public understanding and acceptance, water quality in the rainwater and the surrounding watershed, and government and private sponsorship and support. The development of this stormwater management and recovery system is projected to bring about a huge social change as it is projected that there will be a significant reduction in the water shortage and water importation into the Shenzhen city area, which will affect the availability and cost of water for residents, changing their daily lives and understanding of water. Environmental impacts to be considered from the development of the stormwater management collection system is the vast amount of water that will not be leaving the city via storm sewers or flooding and any of the associated impacts that might have. This undertaking is a huge financial endeavor with total investment for the whole Sponge City program estimated to cost anywhere from 300 billion to 1 trillion is U.S. dollars for both private and public entities over the course of 10 years. Trouble with managing stormwater and the resulting flooding with green infrastructure is not a new problem, as has been illustrated in a case study involving Cleveland and Milwaukee, (Keeley et al, 2013). Keeley et al, describes the environmental impact that green infrastructure can have on larger industrial cities and its overall importance especially regarding reducing rainfall runoff over impermeable surfaces and revitalizing cities green spaces. With the successful application of green infrastructure in cities in the U.S., the Chinese effort that is significantly more centrally led and funded stands a good chance of achieving its goals of retaining most of the rainwater that enters the city. Shenzhen China’s efforts to implement WRE can be simplified to a cause and effect relationship, where the cause is a water shortage having risen from an increased population in areas with limited water resources and an overwhelming waste of that rainwater resource into problematic flooding, and the effect was the implementation of stormwater management systems that have successfully captured and utilized that rainwater for other beneficial purposes.

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Figure 1 A map of the newest district in the city with different green infrastructure projects in varying sectors shown.

References:

  1. Chin, D. A, (2013), Water Resources Engineering Third Edition, Pearson.
  2. Harris M. China’s sponge cities: soaking up water to reduce flood risks. The Guardian. https://www.theguardian.com/sustainable-business/2015/oct/01/china-sponge-cities-los-angeles-water-urban-design-drought-floods-urbanisation-rooftop-gardens. Published October 1, 2015. Accessed April 1, 2019.
  3. Shenzhen as China’s Pioneer “Sponge City”: Dialogue with The Nature Conservancy. ELEVATE. https://www.elevatelimited.com/insights/shenzhen-as-chinas-pioneer-sponge-city-dialogue-with-the-nature-conservancy/. Published December 12, 2018. Accessed April 1, 2019.
  4. International Water Association. https://iwa-network.org/city/shenzhen/. Published January 1, 2018. Accessed April 28, 2019.
  5. Keeley M, Koburger A, Dolowitz DP, Medearis D, Nickel D, Shuster W. Perspectives on the Use of Green Infrastructure for Stormwater Management in Cleveland and Milwaukee. Environmental Management. 2013;51(6):1093-1108. doi:10.1007/s00267-013-0032-x.