Build a (Sea) Wall?

The seas are rising, the storm surges are worsening, and the city is booming all at the same time. How do we protect what makes Miami special, without losing it for good?

Dueling plans from the Army Corps of Engineers and Local Leaders offer vastly different views to tackling the same problem: Storm Surge. The Army Corps plan from last year takes a hammer to a nail and proposed a concrete sea wall, with gates at the various boat entrances. City officials and local organizations are rarely unified in opposing this solution, but do not want to lose key parts of the plan, including fortifying city services such as water treatment plants, police and fire stations. The Army Corps has since updated this proposal, bringing the wall inland, focused on the rivers, and mitigating storm surge using gates that can be closed. This plan is estimated to cost $8 bn, with the Army Corps paying for 65%.

In response to the initial plan, the county leaders commissioned renderings and an alternate plan paid for by Swire Properties. It proposes large berms along the water, with barrier islands, natural mangroves and oyster reefs. These methods are shown to break down waves from storm surge, and prevent damage. Leaders also commissioned scary renderings of flood walls blocking views of Biscayne Bay, showing their green baywalk as the beautiful alternative. The Army Corps Plan has since changed, but these renderings were effective in bringing together opposition for the plan.

While these options help to mitigate and break up storm surge, they do little to mitigate the effects of sea level rise. Mayor Cava last week released a county-wide plan to mitigate the effects of 2ft of sea level rise by 2060. It includes voluntary property buy-backs, raising minimum finish floor elevations, blue and green belts; And sea walls and flood gates. This proposal represents the first county-wide masterplan to address Sea Level Rise, and takes a serious look at planning for the future. Miami-Dade is working to leverage every bit of federal funding offered to mitigate sea level rise, as their plan could cost tens of billions of necessary dollars.

It is hard to make sense of all of these different plans. Some are building and zoning codes, some are sea walls and gates, and some are parks. I was confused as to the Army Corps plan, and asked Alex Harris, the Miami Herald environmental reporter (see twitter thread below). What is clear, is that the long-term survival of our county requires multiple solutions to multiple problems, stemming from sea level rise. Homes on the water must be raised in order to withstand periodic flooding. River-ways need to be widened using greenery to accommodate overflow. Roads all over the county need to be raised. And inland sea walls may have to be constructed to mitigate the increased risk of storm surge due to sea level rise.

However, we have to build infrastructure smartly. Building a 13-ft tall wall along Biscayne Boulevard, or NW 2nd Ave seems like a last resort idea, that throws urban design, planning, and natural solutions out the window. River entrances need to be managed, but sea walls must be integrated with pedestrian paths, transit, and roadways.

Perhaps integrating a seawall with an elevated green pathway and bikeway? The Malecon in Havana, offers an example of a sea wall that is a social hub for the city, due to its thickness and height, acting as a long urban bench. La Promenade Plantee is the original Highline in Paris, an elevated pathway through the city on a decommissioned railway line that offered retail space below it. Both are examples of urban infrastructure that provide a social and economic resource for the community.

The task is daunting. Protecting Miami from the effects of climate change, worsening storms, and rising seas requires many solutions working together. Some will be natural, and some will have to be physical. But we have to protect the urban fabric that makes Miami special, or we will never be able to raise enough money to save it from sinking. Let’s make something that is a benefit to our community, not just a band-aid. Let’s combine natural and concrete solutions to leverage both federal and local dollars. Let’s build a sea wall that we can be proud of, in our fight against rising seas.


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Sources:

https://www.npr.org/2020/06/13/875725714/a-4-6-billion-plan-to-storm-proof-miami

https://miami-dade-county-sea-level-rise-strategy-draft-mdc.hub.arcgis.com/

https://www.saj.usace.army.mil/MiamiDadeBackBayCSRMFeasibilityStudy/

https://www.miamiherald.com/article245085975.html

https://www.miamiherald.com/news/local/environment/article249154455.html

https://www.miamiherald.com/news/local/environment/article249531405.html