Designing Landscapes that Work with Natural Processes
A NWNL NEXTGEN Blog post- during my senior year at UNCW I interned with No Water No Life and contributed to the research of watershed values, threats and solutions on a global scale. I have added all of my archived articles to this site for further reading. Some images and text have been changed or updated since original postings on NWNL.
Introduction
Major cities and highly-developed urban areas contain large amounts of impervious surfaces. Resulting elevated levels of stormwater runoff leave cities subject to an increase in extreme flooding events and pollutes nearby waterways. According to the Natural Resource Defense Council [NRDC], stormwater runoff is estimated to contribute 10 trillion gallons of untreated wastewater into our lakes, rivers, and streams each year [Denchak, Melissa]. This wastewater contains numerous pollutants including various chemicals, sewage waste, oil and gas, cigarette butts, and fecal bacteria from pet excrement [Environmental Protection Agency].
Urban architects and planners, environmental groups and scientists are coming up with ways to help major cities lower the risk of extreme flooding events as well as capture pollutants from stormwater runoff. One way to mitigate stormwater runoff is green infrastructure. Incorporating elements of green infrastructure when designing roads, superhighways, rooftops and sidewalks allows pollutants and excess runoff to percolate through the ground and thus become somewhat filtered before entering the water table. As well, when stormwater infiltrates into the ground via pervious pavement and other forms of green infrastructure, it helps prevent drainage systems from overflowing and therefore helps combat flooding.
Image Curtesy of Wiki Commons
Green Infrastructure
Green infrastructure encompasses several practices that reduce the amount of runoff by incorporating permeable surfaces and other plant and soil systems to store, infiltrate and allow for evapotranspiration of surface runoff [EPA]. These methods involve building surfaces that absorb large amounts of rainfall, therefore greatly reducing the amount of stormwater runoff [Berland, A., Shiflett et al.]. Incorporating green roofs, rain gardens, bioswales, and pervious surfaces offers cities a solution to mitigate extreme flooding events while also helping purify the cities’ air [Environmental Protection Agency]. Compared to grey infrastructure, which consists of human constructed dams, seawalls, roads, etc., green infrastructure incorporates mother nature in the forefront of development [Conservation].
Example of gray infrastructure, courtesy of Wikicommons
Parks allow for recreation and have been proven to provide healing cognitive benefits, but one major aspect of parks is usually overlooked [Weir, Kristen]. Parks and green spaces allow for capturing stormwater runoff and replenish drinking water supplies. When urban development and recreational areas incorporate green infrastructure, runoff is greatly reduced. Green infrastructure can also save money for cities. According to the American Society of Landscape Architects, green infrastructure can reduce costs by a total of 44.1% compared to grey infrastructure [Gallet, D]. The reduction of grey infrastructure lowers the operation, repair and maintenance, and infrastructure replacement costs by utilizing methods that require less upkeep [Gallet, D].
Landscape architect Kotchakorn Voraakhom has designed an exemplary model of a functioning green space in Bangkok. Her design incorporates a detention lawn, green roof, two functioning wetlands, and a retention pond containing electric bikes that filter the water as people cycle through the pond [D’Arcy, Patrick]. The Park is designed to mitigate the effects of climate change and help improve urban issues associated with severe flooding events.
An aerial view of Chulalongkorn Centennial Park, Voraakhom’s latest completed project in Bangkok
Conclusion
When cities rely solely on gray infrastructure, large portions of land are paved over and altered in significant ways. However, incorporating and building around the natural processes of mother nature can bring us closer to a cleaner, safer, and more robust environment. We must reimagine the ways we build our cities. Instead of designing “concrete jungles,” we should focus on working with the landscape and incorporate green spaces into urban planning. Incorporating these best management practices will help combat risks and damages associated with climate change. Imagine the amount of water cities could save if investment and involvement in green spaces was considered a fundamental part of urban planning!
Green Roof- Curtesy of Squarespace
Sources:
Berland, A., Shiflett, S. A., Shuster, W. D., Garmestani, A. S., Goddard, H. C., Herrmann, D. L., & Hopton, M. E. “The role of trees in urban stormwater management. Landscape and Urban Planning.” March 10, 2017. Accessed June 1, 2021 by MO. https://www.sciencedirect.com/science/article/abs/pii/S0169204617300464.
Conservation. “Green-Gray Infrastructure: Working with nature to protect vulnerable communities” Accessed Jun 22, 2021, by MO. https://www.conservation.org/projects/green-gray-infrastructure
D’Arcy, Patrick. When Bangkok floods (and it floods a lot), this park does something amazing. TED, Jul 20, 2018. Accessed Jun 6, 2021, by MO. https://ideas.ted.com/when-bangkok-floods-and-it-floods-a-lot-this-park-does-something-amazing/
Elvidge, C. D., Tuttle, B. T., Sutton, P. C., Baugh, K. E., Howard, A. T., Milesi, C., Bhaduri, B., & Nemani, R. “Global Distribution and Density of Constructed Impervious Surfaces.” Sensors (Basel, Switzerland). September 21, 2007. Accessed June 1, 2021 by MO. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3841857/.
Environmental Protection Agency. “Benefits of Green Infrastructure.” EPA, May 28, 2020. Accessed on June 2, 2021 by MO. https://www.epa.gov/green-infrastructure/benefits-green-infrastructure.
EPA. Accessed Jun 12, 2021, by MO. https://www.epa.gov/green-infrastructure/what-green-infrastructure
Gallet, D. “The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental and Social Benefits.” Proceedings of the Water Environment Federation, 2011. Accessed June 4, 2021 by MO. https://doi.org/10.2175/193864711802639741
UN ATLAS OF THE OCEANS. “Human Settlements on the Coast.” Accessed Jun 22, 2021, by MO. http://www.oceansatlas.org/subtopic/en/c/114/
US Department of Commerce, N. O. and AA. “What percentage of the American population lives near the coast?” NOAA’s National Ocean Service. October 31, 2019. Accessed June 2, 202, by MO. https://oceanservice.noaa.gov/facts/population.html.
Weir, Kristen. Nurtured by nature. American Psychological Association, April 1, 202. Accessed June 4, 2021, by MO. https://www.apa.org/monitor/2020/04/nurtured-nature#:~:text=Cognitive%20benefits&text=And%20experiments%20have%20found%20that,Directions%20in%20Psychological%20Science%2C%20Vol.
