We Can Only Build Walls so High: We Must Consider Nature in Efforts to Protect Urban Environments

Faye Gilbert 

For those of us in the New York Metropolitan area, flooding is no small feat, nor is it a new one. Think back to one of the most prominent tropical storms in this area’s history: Hurricane Sandy. For those alive during the storm, especially residents of the New York Metropolitan area, the effects were devastating. In the days following the storm, there were forty-three deaths, six-thousand patients rushed out of hospitals and nursing homes, over a million children out of school for a week, and close to two million residents with lost power in New York City alone [1]. No one went unaffected, and given the sheer monstrosity and unique nature of the storm, it’s no surprise why. 

Not long after Sandy first touched eastern United States ground on October 29, 2012, 51 square miles of New York City— 17% of its landmass— was flooded.  In coastal areas like the Coney Island and Tottenville Peninsulas, flooding was as high as 11 to 14 feet [1]. In the case of these peninsulas, their vulnerability to flooding wasn’t only due to their proximity to the ocean, but also to their being on very low ground. The Coney Island Peninsula area averages around 7 feet above sea level, with some areas as low as only 3 feet above [2]. This was the case for low-lying areas in Jersey, as well. Hoboken, which is directly opposite western bank of the lower Hudson River with from Manhattan, faced similarly drastic flooding in its low-lying areas. This intense flooding was due to the nature of the storm. Sandy led to a massive storm surge in the Atlantic. A storm surge, as defined by the NOAA, is “the abnormal rise in seawater level during a storm…caused primarily by a storm’s wing pushing water onshore” [3]. The height of Sandy’s storm surge was record-breaking. 

This surge and this flooding were unlike anything the New York Metropolitan area had seen or dealt with before— and this was as great of a factor in the destruction as was the storm itself. Before this storm, the urban design of this region had been able to, while not easily and not without great effort, manage modern climate conditions, and thus hadn’t enforced the precautionary measures needed against an environmental disaster of this stature. Take, as a particularly ironic example, Hoboken, whose susceptibility to flooding was built alongside the city itself. In the 18^th century, before the city was founded, it was primarily low-lying wetlands and marshes, with the exception of an elevated island where modern day Castle Point is located. Early leaders and developers of the city, however, had a different vision for the land. Despite the lack of solid ground, the economic benefit of development drove them to drain the marshlands so they could be built upon [9].

The kicker in this story is that the original founders and developer of Hoboken were aware of the coastal risks this decision would entail in the future, but instead prioritized the short-term economic benefits of constructing the city as they did. For Hoboken, Sandy was a devastating example how unsustainable these decisions were—  it flooded the areas its founders had so long ago drained, returning it temporarily to its original state in nature.                               

Fault for this flooding cannot solely be pointed at the carelessness of Hoboken’s founders, however. While Sandy resulted from a unique combination of environmental factors, it was significantly strengthened by overall human impact on the climate. A NOAA study from 2021 determined that the flooding from Sandy was significantly worsened by anthropogenic (human-caused), sea level rise. Simulation models used to conduct the study determined that “87-92% of observed sea level rise in New York City [could] be directly linked to anthropogenic climate change” [8]. The irony of this flooding could be thought of as a not-so-gentle reminder from nature that, while urban landscapes are beneficial to people, they aren’t for the environment.

Climate change has been, in part, caused and absolutely worsened by urban activity. The driving force of global warming are carbon emissions into Earth’s atmosphere. Recent data from ClimateTrace placed New York City high on the list of global cities with the highest carbon emissions, finding that it emitted 160 million metric tons in 2024 [6]. Global warming is the primary cause of sea level rise— higher oceanic temperatures cause seawater to expand and ice caps to melt [8].

Post Sandy, there was a clear need for redesign of these urban areas, and a clear opportunity to do so. Destruction made rebuilding necessary, and it made sense to rebuild preventatively. This was the initiative of the “Rebuild by Design” Project, a challenge created by the federal government under the Obama administration that aimed to encourage innovative flooding solutions in the northeast Atlantic region. The Hudson River Rebuild by Design Project (RBD) was the strategy developed by local officials and engineers for the Hoboken area specifically. This project is still in the process of being implemented today, and it's on stage two of its construction process. This plan implements on-land infrastructural changes to Hoboken based across four strategies to manage stormwater and flooding: Resist, Delay, Store, Discharge [9]. A significant element of its forms of construction were its earlier development of green nature-based infrastructure. Green infrastructure, as opposed to the typical “gray” infrastructure that models urban areas, aims to reduce the overall imperviousness of cities. Cities, especially those such as Hoboken that were developed as early as the 19^th century, are typically full of impervious surfaces, or surfaces that water cannot seep through, such as concrete and pavement. This raises issues both in terms of flooding and environmental impact. Hoboken, and many cities developed in similar periods, also implemented combined sewer systems, which connect storm drains and sanitary sewers. 

 Due to the imperviousness of the majority of gray cities surfaces, the amount of water from rainfall and from heavy storm flooding that reaches the combined sewer systems often causes them to overflow, leading to a release of untreated runoff and sewage water into estuaries and oceans. This was the case during Sandy— a total of 1.6 billion gallons of untreated sewage drained into New York waterways alone [4].

Green infrastructure initiatives such as raingardens, green roofs, permeable pavements, and resiliency and waterfront parks are wonderful in mitigating this issue, and were a large factor in the Rebuild by Design Hudson River project. The presence of green areas not only absorbs some of the water that would else go drain into combined sewer systems, but it also helps to filter unwanted pollutants out of some of the water that does. In addition to this implementation, Hoboken has made efforts to do away with some of the original combined sewer system in the first place, although not entirely.

In an ideal telling of this story, and an equally unattainable ideal state of the climate, this initiative would have been enough to entirely mitigate coastal flooding and climate concerns that threaten this urban region. However, this project has spanned the length of a decade. Global warming has only increased in that time, and the sea level has increased with it. Due to the intensity of sea rise, engineers in urban areas are concerned that on-land mitigation strategies, such as Rebuild by Design, won’t be sufficient to offset the possibility of other intense storm surges, like the one that drove Sandy. They have turned to the idea of beginning closer to the source primarily through in-river forms of infrastructure known as a storm surge barriers. However, the tendency of negligent urban infrastructural planning we saw in Hoboken’s founding, and that’s been similarly present in the development of many areas in New York City, repeats itself here through a disregard for the definite environmental concerns these barriers raise.

Philip Orton, an oceanography professor at Steven’s Institute of Technology with expertise in this area, has conducted research on the possible impacts of storm surge barriers in low-lying areas in New York City that could potentially benefit from them, such as the Jamaica Bay. Orton explains a fundamental issue in the nature of their planning—the frequency in which they might need to be utilized. Storm surge barriers are placed in estuaries, the place where a river meets the larger ocean, and close off this meeting in the case of an extreme weather event, such as Sandy, to minimize flooding. However, due to excessive sea level rise, some barriers may need to be closed more frequently than that to mitigate chronic flooding. Orton explains that this is where concerns arise.

“If it’s only during extreme events, it’s not that big of a deal. If it’s a tide gate that gets closed 100 times a year to stop chronic flooding, then it is more of a big deal.” 

             During closure of these barriers, the water quality of blocked off rivers could be incredibly compromised. As discussed by Yale’s Environmental Journal in 2019, blocking tidal flow causes a build-up in rivers of what typically flows into and is dispersed by ocean water, such as trash, sewage, and runoff pollutants. Both runoff water, if it has picked up chemicals like fertilizers of industrial waste, and untreated sewage typically contain high levels of nutrients like nitrogen and phosphorus. In addition, the reduced tidal flow would slow water, which could reduce the amount of oxygen in it. These conditions form the perfect storm for increased algal blooms, which not only affects drinking water quality, but can lead to massive dying off of aquatic life known as “dead zones” [7].

              This was a concern, Orton explained, raised by environmental advocates around 2020-2022 when the U.S. Army Corps of Engineers conducted studies regarding the impacts of implementing surge barriers in the New York metro region, and they seemed to leave this possibility out. 

             “It’s easy to count dollars” Orton explains, “but when it comes to the ecological health and human safety benefits, those are harder things to quantify.”

            This backlash, along with concerns that surge barriers wouldn’t do much to withstand long-term effects of chronic flooding, led them to instead recommend a set of smaller barrier systems and levies. This plan was combined with on-land wetland restoration initiatives, as well. These initiatives were in favor of the environmentally concerned critics for their benefit to the environment. Many of these same critics believed these efforts will be the most sustainable, as well, in the long run, claiming that “smaller-scale measures are the only thing that will protect the city from sea level rise as the climate warms” [7].

The sufficiency of wetland restoration in mitigating sea level rise impacts points back to the lesson originally imposed by Sandy, especially in areas like Hoboken where the event demonstrated the stubborn and difficult-to-ignore retaliation of nature. 

There is no doubt that, with growing population and growing concentration of populations in urban areas, we must find the best approach to ensuring safety of infrastructure and of people. However, there is no doubt that this must be balanced with the growing effects this has on the climate. As we are now faced with the characteristically human problem of how best to handle the consequences of interfering with nature, it is not entirely up to us to decide if we should restore it to its original form— sometimes it decides for us. 

 

Bibliography

[1]

NYC.gov, “Sandy and Its Impacts,” 2013. Available: https://www.nyc.gov/html/sirr/downloads/pdf/final_report/Ch_1_SandyImpacts_FINAL_singles.pdf

[2]

“Saving Coney Island from the roller coaster of climate change | Cornell Chronicle,” Cornell Chronicle, 2017. https://news.cornell.edu/stories/2017/11/saving-coney-island-roller-coaster-climate-change (accessed May 02, 2026).

[3]

National Oceanic and Atmospheric Administration, “What is storm surge?,” Noaa.gov, 2019. https://oceanservice.noaa.gov/facts/stormsurge-stormtide.html

[4]

“Report Cites Large Release of Sewage From Hurricane Sandy,” The New York Times, Apr. 30, 2013. Available: https://www.nytimes.com/2013/05/01/nyregion/hurricane-sandy-sent-billions-of-gallons-of-sewage-into-waterways.html

[5]

“Climate TRACE Data Show Global Greenhouse Gas Emissions Hit a New Record High in 2025,” Climate TRACE, 2025. https://climatetrace.org/news/climate-trace-data-show-global-greenhouse-gas-emissions-hit-a-new-record-high-in-2025

[6]

P. Bennett, “New Report Names Cities With Highest Greenhouse Gas Emissions,” EcoWatch, Nov. 15, 2024. https://www.ecowatch.com/highest-greenhouse-gas-emissions-cities-2024.html

[7]

E. Royte, “Could Massive Storm Surge Barriers End the Hudson River’s Revival?,” Yale E360, Sep. 24, 2019. https://e360.yale.edu/features/could-massive-storm-surge-barriers-end-the-hudson-rivers-revival

[8]

K. Kiest, “Anthropogenic Climate Change Exacerbated Impacts of Hurricane Sandy, Study Says - Climate Program Office,” Climate Program Office, Jun. 02, 2021. https://cpo.noaa.gov/anthropogenic-climate-change-exacerbated-impacts-of-hurricane-sandy-study-says/# (accessed May 02, 2026).

[9]

R. Hine, “In the 1700s, Hoboken was an island; in 2012, during Superstorm Sandy, 75% of Hoboken was again under water - Fund for a Better Waterfront,” Fund for a Better Waterfront, Feb. 20, 2025. https://betterwaterfront.org/in-the-1700s-hoboken-was-an-island-in-2012-during-superstorm-sandy-75-of-hoboken-was-again-under-water/