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April 26, 2024
Storm surge pummels like a fist when it hits the land. And like a claw, it also drags the land back into the ocean when it recedes. The climate is changing, the sea is rising, and storm surge is predicted to become even more dangerous. We, as a community, need to protect ourselves from this new reality.
At the same time, Biscayne Bay is in critical condition. With gray hardscape shunting pollution into our waterways and replacing native flora, the community is realizing the limits of relying on traditional, concrete means to solve societal problems like storm surge.
So how do we protect ourselves from dangerous flooding driven by storms while preserving the character of our City, the vitality of our neighborhoods, and the health of our Bay? Is gray infrastructure the answer, or can we envision a future where engineering solutions protect our community while blending with natural ecosystem values? And- how do we protect and defend our city while making sure that inequity is not perpetuated? Just a few of the big, existential questions that South Florida needs to face! No pressure!
The Challenge
In 2019, the Corps initiated the Miami-Dade Back Bay Coastal Storm Risk Management Feasibility Study in Miami-Dade County. The study purpose is to reduce coastal storm risk. As part of the planning process, the Corps solicited comments from the community and from stakeholders. Many of the comments they received were overwhelming in support of Nature and Nature-Based Features (NNBF’s). In the right place, NNBF’s can do so much. The use of natural elements and native ecosystems to solve societal problems provides a multitude of benefits. Examples include reefs, sand dunes, and mangrove fringes, which--like speed bumps--can slow down and scramble incoming storm surge, and also have added value of biodiversity and carbon sequestration.
Credit: Local Office Landscape & Urban Design
More on reefs: the high degree of surface area on a reef (because corals are lumpy and bumpy) means that when a wave sweeps through it, the wave encounters lots of friction — and therefore the wave energy is slowed. Studies have shown that over 90% of the wave energy can be attenuated by reefs acting like speed bumps (read more here and here). And as we all know, reefs offer much more than storm surge protection– they harbor biodiversity, provide recreation opportunities, and create economic gains for our community.
Credit: Miami Waterkeeper
When the Corps released its Recommended Plan in 2021, and to the community’s dismay, the agency included miles of divisive walls through neighborhoods and within Biscayne Bay-–even though the Corps’ study acknowledged that floodwalls could disrupt stormwater drainage and flow, thus increasing sea level rise flooding risk and adding additional costs to the County to mitigate. The Corps did not consider the floodwalls’ impact on “compound flooding”, which occurs when two or more types of flooding happen at or near the same time (for instance, flooding from a hurricane occurs from excess rain leading to stormwater flooding, and from the surge of the sea moving over the land).
While the plan did include NNBFs – mangrove restoration areas – these were relegated to the south of the county. Distressingly, the Recommended Plan used a cost-benefit analysis formula that relied on property value loss calculations. This means that high-income areas where home values are in the millions were identified for assistance, while less wealthy areas in the south of the county were excluded from the investment – thereby perpetuating inequity.
The community was united in opposition, from developers and landowners concerned about the loss of waterfront view; residents concerned about divided neighborhoods; scientists concerned with the unintended hydrologic consequences of water piling up behind the wall; and environmentalists concerned about the ecological effects of adding more hardscape to the Bay, when the Bay is dying, and when NNBF’s should be incorporated where possible.
The Downtown Development Authority even commissioned renderings from a landscape architect to show what life would be like “behind the wall”.
Credit: Curtis + Rogers Design Studio
Many of you responded to Miami Waterkeeper’s call to action and contacted your officials about your concerns with the Corps’ proposal. With the community staunchly pushing back on the plan, Mayor Levine-Cava reached out to the Assistant Secretary of the Army to find a better solution. Thankfully, Mayor Levine-Cava negotiated a “reboot” to the process, and the Corps re-initiated the study in August of 2022. Right now, the County is working with the Corps on alternatives to “the wall”.
The county and its team of consultants have envisaged two alternatives. Both concepts contemplate the use of NNBFs. The first (called the Non-Structural Alternative) calls for things similar to the 2021 plan like elevating homes, and protecting public infrastructure – but also increases natural protections by proposing NNBFs like spoil islands, artificial reefs, and mangrove planters in the bay to act like natural obstructions to wave energy.
Credit: Moffatt & Nichol
The other (known as the Atlantic Coastline Alternative) consists of a reinforced dune system on Miami Beach plus massive storm surge gates at Rickenbacker Causeway, Norris Cut, Government Cut, and Haulover inlet - effectively creating a ring around northern Biscayne Bay.
Credit: Moffatt & Nichol
The Way Forward
The process to protect Miami from storm surge is complicated (yep, that may be the understatement of the year). Designs will be years in the making. We are encouraged by the efforts that the County and Corps are making to come up with new solutions. But...The wall is not out of the picture yet! Alternatives will be compared against the previous 2021 plan and a winner picked down the road. It’s possible that the Corps will hew to its old dogma of “gray is good”. Now is the time to weigh in and make sure that plans to protect our community from storm surge also makes sense for our neighborhoods, livelihoods, and way of life.
Take Action
You can email the Corps' at [email protected]. Let them know the following:
- Nature and nature-based features in the right place can offer significant storm surge protection. Hardscapes are killing our watersheds and we shouldn't automatically default to them. In contrast, reefs act as our first line of defense while providing habitat, recreation, tourism, and economic benefits to our community.
- The Corps needs to account for compound flooding. Their plans cannot backfire by making the city more prone to dangerous flooding if they install walls and barriers that disrupt stormwater drainage and flow.
- Public safety must be a primary goal of this initiative, and the Corps should include in their cost-benefit-analysis key metrics to ensure that life safety is on par with property values in evaluating the worthiness of project features.
You can also use their public crowdsource tool to send them comments about features in specific locations at https://arcg.is/0ub0Cf
We all need to work together to usher in a new way of doing business, one that integrates the human environment with nature-based solutions. This problem of storm surge could be an opportunity in disguise, one that would make our city more resilient and more beautiful. Come be part of the solution.
Credit: Curtis + Rogers Design Studio