Miami’s next flood plan
Rendering of Army Corps of Engineers’ previously proposed flood wall in downtown Miami.
The U.S. Army Corps of Engineers has ditched its idea of building a 10-13 foot wall along the coastline of Miami-Dade County and instead is working with local officials on a new flood control plan that involves both man-made and natural solutions. The wall proposal, announced in early 2020, was shot down by residents who said they didn’t want to look at big walls.
The Miami Herald reports the new version of the Back Bay study is a more collaborative effort by the Corps and the county. It involves some of the same elements of the original plan: elevating thousands of homes, floodproofing thousands of buildings, and planting mangroves, growing coral reefs, and other natural solutions. Gone are the big walls but still remaining is the possibility of incorporating mechanical storm surge barrier gates along the barrier islands. Former Florida Department of Community Affairs Secretary Jim Murley who serves as the county’s chief resilience officer, acknowledges that the tradeoff is a lower level of protection against flooding.
The Corps though is used to building things – it’s what they do best. Yet they’ve received similar opposition in other communities. The Herald’s long-time climate and environmental reporter Alex Harris notes in the article that the series of public meetings leading to this updated proposal represents that “the Corps has opened up its process to start considering more ‘comprehensive benefits’” of natural solutions.
In Florida, native mangroves play an important role in protecting our coastlines. We’ve reported in this newsletter on other research that shows that mangroves reduced peak storm surge height by as much as three inches per half mile during hurricanes Charlie and Wilma, which can add up over the space and distance of the surge. The first 100 meters of mangroves are especially important, as they can lower wave height by up to 66%.
The Herald reports that the decision to move forward with this plan will entail another four-year $7 million study that will end with a specific draft about two years after, with public comment to follow. Any full project design would likely take another decade.
LMA Newsletter of 9-11-23
