A persuasive local advocacy and media campaign convinced the U.S. Army Corps of Engineers to conduct a new, expanded study for a $6 billion project to protect Miami from future hurricanes, coastal flooding, and climate impacts. Critics argued that the Army Corps’ initial draft plan for the project, which had proposed a series of sea walls and gates, would have negatively impacted the character of Miami, reduced property values, and cut-off access to important waterfront parks, exacerbating existing inequities in access to public space.
The Miami Mayor’s office and Downtown Development Authority instead demanded a deeper exploration of nature-based solutions, including constructed islands and mangroves, to protect the urban coastline along Biscayne Bay. The Army Corps has agreed to spend $8 million over 60 months, essentially doubling the cost and timeline of the original study, and take a more collaborative approach with city stakeholders.
Key to this shift were renderings created by Miami-based, women-led landscape architecture firm Curtis + Rogers Design Studio for the Miami Downtown Development Authority, which governs the business district. These concepts were included in the Authority’s response to the Army Corps’ Back Bay Coastal Storm Risk Management Study but soon became the focus of public attention and coverage in The Miami Herald and local TV stations, social media discussion, and national coverage in NPR and The New York Times. The authority commissioned visuals that would both show how 20-feet-tall concrete walls along the bayfront would impact the city (see images at top) and demonstrate how a better alternative, rooted in nature, could offer protections while offering many other benefits.
According to Aida Curtis, ASLA, a founding principal at the firm, the Authority gave her firm just two weeks, during the height of the pandemic, to work with coastal and civil engineers to create nature-based design concepts. She explained that the concepts are comprehensive, but more research, modeling, planning, and design work needs to be done to further hone the ideas. Still, the Authority was able to use these concepts for leverage in negotiations with the Army Corps.
“We had envisioned vegetated shorelines with mangroves along with strategically-placed bermed islands in the Bay that would attenuate wave action during storm surges. This is a grey/green solution, not all nature-based, but it would be much better for the community and environment and increase park access,” Curtis said in a zoom interview.
Curtis argues that “this kind of idea is what the Corps should have proposed initially,” and her concepts are line with their stated Engineering with Nature principles, which calls for using nature-based solutions to solve climate impacts.
The Army Corps had engaged Miami-Dade County, which includes the City of Miami, in a series of complex feasibility studies to improve resilience against storms, flooding, and sea level rise. In other study areas, south of the city, the Army Corps did propose nature-based solutions, including mangroves, Curtis said.
But the issue was in the downtown core, they only offered hard grey infrastructure. “We wanted to show the walls as real as they would be, with graffiti and the trash that is common in parts of downtown Miami. People didn’t realize how tall or in-your-face these walls would actually be.”
“Their proposal would also have put many residential communities outside the wall. This lack of thought is what caused the uproar. The city needs a much more comprehensive solution.”
Curtis noted that Miami suffers from significant water management problems. So much groundwater has been extracted through wells that saltwater is now seeping into the water supply. Stormwater runoff and fertilizer use throughout the city and country have caused significant water quality issues, leading to massive fish kills. In Miami Beach, a system of pumps have been instituted to draw out flood water. “But they discovered that during a hurricane, there is no power, which means no pumps. Grey infrastructure solutions for water management have failed in Miami.”
There are many arguments for designing nature-based solutions — using landscape architecture strategies to help solve Miami’s problems. Curtis said they offer multiple environmental and equity benefits.
On the environmental side, mangroves reduce inland flooding by serving as a barrier against waves. But they also clean and oxygenate the water while providing habitat for sea life and sequestering carbon.
Given housing has become increasingly unaffordable, lower-income communities in Miami have been pushed west, inland. “Park and open space is very limited in the city. Low-income and immigrant communities have limited access to the waterfront.”
One of the benefits of natural coastal infrastructure is that it can double as park land. “New islands in the bay could be designed to be accessible public space that people can enjoy.” Her firm’s proposal would create 39 acres of new public recreational areas.
Curtis said next steps will be key. The Army Corps and city will need to “bring in more stakeholders and get more community input.” The city is expected to also undertake their own complimentary planning effort.
Perhaps the one positive effect of the initial Army Corps study is that “more people in Miami are now paying attention to this and more are involved in climate action,” Curtis said. “The intended audience of the response was the U.S. Army Corps of Engineers, but the Authority’s report and our images transcended and went viral.” There is also now greater awareness of the value of nature-based solutions and “the detrimental effect grey solutions can have on cities — the severe damage they can have on quality of life.”
OK, let’s start with the Corps of Engineers proposal for concrete sea walls to protect the city from storm surge, waves and possible future sea level rise. Concrete walls have been used throughout the US and other nations to reduce the effects of flooding along rivers and in some cases reduce seaside storm effects. The walls do not have to be plain, smooth, gray, boring surfaces. For instance Google “Tug Fork Valley Floodwalls” or “Matewan” floodwall and look at the cast in place graphics used on those walls to enliven the visual interest to and education of the population. The Matewan, WV floodwall includes the entire history of the town cast in place on the high walls that protect the city. Other floodwall graphics have been used along I-71 in Columbus, Ohio and a floodwall in Louisiana. Its not hard to design graphics cast in place, there are suppliers of cast in place forms for this work and the additional cost is minimal. I’m sure that a design competition arranged by the City of Miami in concert with the Corps of Engineers could spawn a myriad of graphic solutions that would turn that solemn wall design into a fascinating visitor attraction. Much better than graffiti.
Second let’s consider the “nature” design islands being proposed, although the islands are much more visually pleasing to the eye and much better for shorebirds and other aquatic creatures, loading tons of rock and soil material into the bay isn’t usually considered good ecological practice regardless of what sets atop the fill material. Also, the islands would certainly reduce the effects of waves associated with tropical storms and hurricanes. However, the islands would have minimal effect on storm surge and possible sea level rise. There are numerous islands in the Gulf coast offshore from Waveland, MS but Katrina just laughed at those natural barriers and put 25 feet of storm surge on that poor community. Were sea levels to rise to the level some hysterics are claiming to occur, Miami would be underwater despite the artificial islands. There is certainly room for improvement of the Corps original wall design but remember what the goals are for Miami’s future in a changing environment. Design for those goals. Great article thanks.