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Ironically, while well-intended, continuing to raise and fortify When asked about including mangroves in future waterway
these seawall structures can also have unintended effects, such restoration and coastal flood mitigation projects Dr. Gassman
as increasing wave energy and erosion, which, in turn, can said, “We hope to secure funding in 2024 for an Urban
dramatically reduce marine habitat. Sea-level rise will also Forestry Master Planning process to identify areas and
result in higher storm surges, increased risk for flooding (as we techniques for tree canopy improvement and specifically
continue to see) and an increasingly rapid rate of erosion of identify locations where mangrove habitat enhancements
coastal habitat, all of which can be potentially damaging to would be appropriate and feasible.”
valuable public and private development.
Mangroves, living-seawalls and hybrid reef designs are just some
Green-Gray engineering approaches to many of these of the many innovative green/grey resiliency projects currently
grey cement seawall projects have shown great promise in underway in many coastal cities here in the United States and
offsetting the negative effects of the cement structure and throughout the world. U.S. cities like San Francisco, Seattle,
can actually contribute to less damaging wave action and Boston, New York and many of our own neighboring cities such
improved water quality and marine habitat. And adding as Miami, Tampa, Sarasota and Pompano Beach, are all joining
living material such as oysters, mussels, seagrasses and in to prove eco-engineering can help mitigate storm surge and
maintained mangroves to seawall tiles brings additional help restore our priceless oceans and waterways.
benefits. When these organisms are added to the panels that
are properly attached to or installed in front of new or already What the specialists and experts in the
existing seawalls, they not only aid water quality conditions field are saying
and the marine ecosystems, they also provide significant wave “South Florida is an incredible environment, but, unfortunately, it’s
energy dissipation and erosion control. in decline,” say Dr. Keith Van de Riet, AIA. Dr. Van de Riet is an
award- winning professor who was affiliated with Florida Atlantic
A renewed and increasing appreciation University until 2015 and is currently at the University of Kansas.
for mangroves Dr. Keith added: “A large part of the reason for this is how we
Mangroves, which can now be professionally maintained, build. There’s virtually no natural habitat along the waterways,
are included in many of these green-enhancement projects. where seawalls and bulkheads have replaced tidal ecosystems.
These highly adaptable and durable tropical shrubs and trees I’ve watched mullet literally jumping against seawalls trying to
are the superheroes of our environment. They are the gift that evade predators. Along these waterways, mangrove shorelines
keeps on giving, providing immeasurable benefits: from their and oyster reefs would have been the dominant features until the
positive role in fisheries, to improving water quality by filtering canals were dredged and developed.”
out unwanted pollutants such as our hugely problematic There are a variety of living seawall options. University of
fertilizer runoff. Mangroves also capture massive amounts of Miami is experimenting with a modular marine estuary system
carbon dioxide emissions and other greenhouse gases from they call “SEAHIVE”. Dr. Landolf Rhode-Barbarigos, who is
the atmosphere. And on top of all that, they help mitigate an Assistant Professor of Civil & Architectural Engineering
storm surge wave energy and coastal flooding.
at University of Miami, says: “SEAHIVE elements are

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