Florida has a climate change challenge. Seas are rising and hurricanes keep on coming. The state, with more than 1,300 miles of coastline, has to figure out how to keep that water out of places it isn’t supposed to be, including our neighborhoods, businesses and living rooms. There is no single solution, no magic bullet. And some of the change is already baked in, no matter the amount of greenhouse gasses pumped into the atmosphere going forward. We will need to embrace new technologies and innovative engineering. In Florida, that will take many forms, but one thing for sure, it will mean building stronger sea walls. And lots of them.
Sea walls protect homes in communities all over Florida and Tampa Bay. Without them, storms and waves would pull many coastal neighborhoods into the sea. The concrete and metal walls guard multi-million dollar mansions on Davis Islands and Tierra Verde and more modest abodes in Crystal River and Apollo Beach. They have been around for decades, silent sentries helping families live out the Florida dream of living next to the water.
Sea walls aren’t ideal. They come with their own complications, from increasing erosion to damaging sea beds. And they cannot be our only protection against rising seas. But they are proven effective at keeping water at bay — and they aren’t going anywhere. They protect too many homes and businesses that too many people rely on, including the taxes generated from those properties. Sure, the state will have to make hard decisions about retreating from a few highly vulnerable coastal areas. About 40 percent of St. Petersburg, for example, is vulnerable to storm surge from a mere Category 1 hurricane. But in the short term don’t expect a massive migration away from the water. As seas rise and hurricanes threaten, the question isn’t how to get rid of sea walls, but how to build better ones. The good news is that efforts are already under way.
Going forward, sea walls promise to be higher, stronger, more durable and better designed to absorb waves and reduce damage to sea beds, the Miami Herald’s Alex Harris reported in her close-up look at sea walls and mangroves. Some concrete sea walls already contain fiber-reinforced polymer instead of steel rebar. The polymer is twice as strong and about one-quarter as heavy as steel, and it doesn’t corrode. It’s about 15 percent more expensive than rebar, but it should last longer in a salty environment, prolonging the life of the sea wall.
Researchers are experimenting with different concrete mixes to help promote coral growth. Others are using sea water in the concrete mix to cut down on fresh water use. In Miami Dade, new seawalls also require a pile of rocks — known as riprap — as their base. Also, look for a LEGO-type approach to some sea walls where additional bricks are easily added to an existing sea wall in future years. “This is the time for innovation,” one researcher told the Miami Herald. Exactly. We can’t keep doing the same things and expecting the same results, not with seas on the rise.
And what about mangroves? They can help in some circumstances. They play a role in softening the waves created by hurricanes and other storms, but only if they are in the right place and in enough quantity. One researcher told the Herald that mangroves need to be at least 100 meters long to dissipate waves. That’s a mangrove that stretches the length of a football field out into the water. We should protect existing mangroves and grow more of them, but we have built too many homes in too many vulnerable areas to rely on mangroves alone for storm protection.
The most aggressive carbon reduction schemes won’t do much to keep Florida’s seas from rising by 2 feet by 2060. That’s not to say we should give up on mitigating climate change. But we cannot ignore reality. The seas will rise, and local and state governments need to take practical steps now to brace for the impact. Innovation and technology, in their many forms, will play a leading role. One small way that is already happening is in building better sea walls.
____
Editorials are the institutional voice of the Tampa Bay Times. The members of the Editorial Board are Editor of Editorials Graham Brink, Sherri Day, Sebastian Dortch, John Hill, Jim Verhulst and Chairman Paul Tash. Follow @TBTimes_Opinion on Twitter for more opinion news.
