Is your coast storm ready?

Hurricane Matthew poses a major threat to the U.S. southeast coast, thanks to its strength, breadth and forecast duration traversing the Atlantic coasts of Florida, Georgia and South Carolina (as of current predictions). Projected to approach the southeast Florida coast as a Category 4 storm, forecasts show it moving northward in close proximity to the coast for upwards of 36 hours – with an uncertain track making a continued hostile wave climate likely to attack the southeast coastlines for days to come.

This kind of multi-day, multi-tide cycle storm events wreak havoc on even the healthiest of shorelines – meaning coasts with wide sandy beaches, high vegetated dunes and well-built structures elevated to avoid the worst of the waves and surge. These healthy shorelines will still suffer damages in a storm such as Matthew, but each of the elements that define a healthy beach will help protect the upland property and habitat in a unique way, while also greatly reducing the human suffering and expensive response-and-recovery efforts afterwards:

• Wide beaches can keep punishing waves away from dunes and uplands property, as the beach sand is sacrificed to absorb the onslaught of water and waves as long as possible – acting as a shock absorber against a storm’s fury.
• High stable dunes offer a second line of protection against waves and (in particular) storm surge, often able to contain the rising waters and lessen the destruction to upland property behind those dunes.
• Finally, well-built and elevated structures have a far better chance of surviving even a storm of Matthew’s magnitude. If waves can stay below a structure’s main floor and winds can be kept from breaching a structure’s integrity, there’s a much better chance coastal residents will have a home or business to return to once the storm is past.

It may be too late to achieve that if your beach doesn’t already fit that description, but this is a goal you should set for your coast. That’s a target that takes time and planning to achieve, but one that pays off in terms of damage reduction and community recovery.

Coastal managers must look over their beach with a critical eye – looking for vulnerable infrastructure such as roads and utilities as well as littoral weaknesses and likely problems such as hot spots that will need to be shored up or low spots prone to overwashing in even routine storm events. That will help customize both preparation and recovery efforts, as well as guide future work to make your coast more resilient overall.

Has your community – meaning residents, visitors and businesses — planned for a post-storm beach profile and coast? They may be surprised at the sand loss for the visible dry-sand beach, but may need to be reminded that sediment was just moved offshore due to the scouring nature of storm waves, and it will migrate back onshore once waves and currents return to normal. That’s also a good time to educate communities how coastal systems work, and to remind communities of the importance of pre-event protection for upland properties and infrastructure.

Remember, there are a number of ways a storm can attack your beach and community, and you need to be ready for each of them:

• Waves: The most obvious destructive force on the ground during a storm, scouring away sand and then upland ground, buildings and infrastructure once the protective beach is gone or the storm surge pushed the wave zone landward. Your best defense is to relocate critical infrastructure away from the hazard zone and to have a wide beach and elevated structures, with perhaps some hardening of critical infrastructure such as roadways and bridges in vulnerable areas that cannot be relocated areas.
• Winds: Destructive on two fronts… as an assault on structures and infrastructure either directly or by accelerating other wind-borne items as missiles, and as the force which piles up water and waves to push surge shoreward as a storm makes landfall. For the former, good building codes (to enhance building integrity in the face of assault) and removing potential missiles (by cleaning up debris and small items pre-storm) will help. For the latter, locate structures away from the inundation zone and make sure structures and infrastructure are reinforced and elevated with a wide protective beach and high dunes.
• Surge & tides: Perhaps the most serious destructive force, especially in slow-moving storms that have a lot of time to build their watery momentum before landfall. As was seen in Sandy (a minimal hurricane for wind, but a monster in terms of size and surge), surge and tidal rises can cause flooding problems on both sides of a barrier island. As before, strong elevated structures and infrastructure behind a wide beach make a real difference… but also look for unsuspected vulnerabilities, such as low-lying bayfronts subject to flooding or evacuation routes with weak links that will wash out or over too quickly.
• Rainfall flooding: On top of everything else that’s happening, a wet storm wreaks its own special havoc – both further inland, as creeks and streams turn into some much larger and low-lying areas because instant lakes, and along the coast, where surge and high tides prevent drainage of rainfall flooding. Look at your area’s flood risks and drainage systems – particularly those that rely on tidal outfalls to carry away excess water.

The most important step you can take, however, is to heed local emergency managers when they tell you how to prepare for storm dangers and what to do to survive an approaching storm. They are more aware of local conditions and vulnerabilities, are working with the most up-to-date information and probably have the best handle on the true nature of the storm situation – so listen to them.

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ABOUT ASBPA: Founded in 1926, the ASBPA advocates for healthy coastlines by promoting the integration of science, policies and actions that maintain, protect and enhance the coasts of America. For more information on ASBPA, go to www.asbpa.org, Facebook or www.twitter.com/asbpa. This information is provided by the American Shore & Beach Preservation Association. For information, to change your email address or to unsubscribe from this list, contact us at exdir@asbpa.org. A complete collection of Beach News Services articles is available for media access online at https://asbpa.org/news-archive/.