The Fall of 2022 wasn’t very kind to Florida. Hurricane Ian hit the Southwest coast as a Category 4 storm, bringing winds near 150 mph and storm surge to the coast, and excessive rain far inland. Hurricane Nicole followed about 6 weeks later, with winds of 75 mph as it hit the East Coast, and another storm surge. However, this was much worse, since the dune system hadn’t yet recovered from Ian’s damage.
“Storm Surge: A dome of water pushed onshore by hurricane and tropical storm winds. Storm surges can reach 25 feet high and be 50-1,000 miles wide.”
Federal emergency management agency
The water rushing onto the shore is only part of the problem. Storm surges also push sand, buildings, and smaller items inland, over roads, and against other buildings. It scours underneath foundations, sea walls, and in-ground pools, removing the sand that holds them up. And, finally, the water either sits there, slowly draining away or rushes back out to sea, carrying parts of buildings and countless other objects with it.
As I’m sure you’ve heard, “Mother Nature always wins.” And yet, we continue to want to live near the water and watch sunrises and sunsets, from our beach chairs or balconies. Mitigation, and recognizing the challenges, are our only choices.
The Challenge: Mother Nature
Sand is not stable. The currents carry sand from one place to another. One beach grows wider while another disappears. We employ the Corps of Engineers to “replenish the beach.” Mother Nature uses storms to redistribute it again. It is a natural occurrence, so it is an ongoing battle.
Mother Nature also uses sand to protect us. The sand dunes protect homes, and the barrier islands protect the mainland. Some places employ sand fencing to prevent people from walking over the dunes, as well as to collect wind-borne sand to help build up the dune system.
The sugar sand beaches on Florida’s west coast are actually made of quartz washed down from the Appalachian Mountains (which were formed at the end of the age of the dinosaurs). The other white and golden sand beaches of Florida contain a mix of quartz, coral, and shells.
We watch children build sand castles, and know that the waves will soon take them away, clearing the beach for another day of castle-building.
What Happens to Homes in Mother Nature’s Way
On the East Coast of Florida, Vero Beach (north of Miami) is where Nicole came ashore. The damage there was mostly due to water inundation.
However, Wilbur-by-the-Sea (NE of Orlando) had massive coastal damage to structures. There were photos of homes hanging off sand cliffs overlooking the beach. Why did that happen there?
According to the Florida Department of Environmental Protection’s report Hurricane Ian & Hurricane Nicole – Preliminary Post-Storm Beach Conditions and Coastal Impact Report, published December 2022, both Vero Beach and Wilbur-by-the-Sea had the same degree of beach and dune erosion damage, Category IV, the highest degree of erosion. However, Wilbur-by-the-Sea has almost no dunes protecting it, while Vero Beach has a lot of dunes.
Storm Surge damage scale, from I. (Minor Beach Erosion to the beach near the shore, but no damage to dunes) to IV. (Major Beach Erosion, where more than 10′ of dune is eroded, including the entire dune being removed by the storm surge).
FROM FEMA REPORTS
I have never been to Wilbur-by-the-Sea, so I don’t know what happened to their dunes before Ian and Nicole hit. However, we can look at Satellite photos to compare the 2 areas. Notice the red line on the photos below: the Coastal Construction Control Line (CCCL) protects the beach and dune system, which then protects environmental habitats and property inland. New buildings must be built even stronger than other local buildings if they are on the beach side of this line. Notice the differences between Vero Beach and Wilbur-by-the-Sea.
Satellite images courtesy of the Florida Department of Environmental Protection as part of the CCCL Maps.
Satellite images courtesy of the Florida Department of Environmental Protection as part of the CCCL Maps.
In both places, homes are built on the beach side of the CCCL. Perhaps they chose to be there, or perhaps they were built before the line was drawn.
Mother Nature pushed a wall of water onto land and found sand dunes secured in place by plant roots in Vero Beach, while she found nothing to keep the waves from undermining the sand under homes in Wilbur-by-the-Sea. As you can see, it’s no wonder the houses in Wilbur-by-the-Sea were impacted so much worse by the storm surge. No dunes = more damage. Building on top of dunes = more damage.
Similar damage occurred on the Southwest coast of Florida, too. While the impacts of wind were greater, the homes protected by sand dunes, and raised on stilts, fared better against the storm surge than homes at ground level without dunes (many were directly on the beach, or simply on canals).
We also saw a stark reminder of storm surge when Hurricane Michael hit the Panhandle of Florida in 2018. An estimated 9-14 feet of storm surge completely took out many of the one-story concrete block houses on Mexico Beach, which had been built at ground level. Only their concrete slabs were left. In other areas, sand was pulled out from under stilt buildings, too, lowering the ground: 6 feet of sand was missing under one house surveyed by the Florida DEP. Imagine, returning home after evacuating for a storm to find that the bottom of the staircase up to your house now starts 6 feet above the new ground level!
(In the photo, note where the white paint on the columns begins – and let your eyes travel to the right side of the photo, showing a pickup truck in the background, and a staircase stopping mid-air.)
Making the Decision to Live with Mother Nature
Although you could conservatively decide that the safest place to build is a place that avoids all natural disasters, you would not find that place. Earthquakes, tornados, floods, hurricanes, wildfires, hail: they touch all our homes. The decision, then, is how much you are willing to build stronger and your willingness to risk your life, property, and money in doing so.
Storms and their aftermath focus our attention on the construction and engineering of buildings which we normally don’t think about. The building codes are updated every 3 years in Florida, and although they are minimum requirements, they were massively overhauled in the 1990s following Hurricane Andrew. That storm hit Miami in 1992 as a Category 5 hurricane with winds of 150 mph and a storm surge of almost 17 feet. Since an average house has 8-foot-tall ceilings, the storm surge was literally the height of a 2-story house.
But we have known the dangers of storm surges for much longer. There have been many tragedies in the past about villages suddenly being wiped off the earth due to a surge of water, and the villagers swept out to sea. Although it is much more recently that we are learning the impact of more and more people and buildings occupying areas near the water. Our chances for damage are just higher now.
In regard to storm surges (and hurricanes and flooding), sand dunes protect the beaches as mangroves similarly protect other parts of our land. Although these are often replaced with seawalls, the seawalls eventually break down or need to be rebuilt. Mother Nature simply erodes the sand from underneath their foundations, and waves continually aggravate their structural integrity. This re-building must be taken into consideration when someone decides to build a seawall, a pool, or a home along the water.
Mitigation: Options for Your Home
Can’t see the water from your property because the mangroves are so tall? Perhaps leaving the mangroves and pruning their tops would be agreeable. Florida allows mangroves taller than 6 feet to be trimmed, as long as you meet other requirements.
(Mangrove Trimming Guidelines for Homeowners (publication) is available on the Florida Department of Environmental Protection website)
Can’t see the water because the sand dunes block your view? Adding an upstairs addition, or building higher, will give you the view and may lower your insurance premiums (if raising living levels above your required flood elevation).
For additions or new homes, the foundation should also meet current codes, too. Larger, deeper foundations help the house withstand the forces from storm surges, both the water rushing past as well as the sand being eroded away. Geotechnical reports may be required to help make this decision – many coastal buildings stand on piles, long columns that go far down underneath the sand. Others can be supported with larger footings, like a duck’s webbed foot.
Replacing walls with columns on the ground floor will let the storm surge pass through, too. Although structural walls are allowed in A flood zones, in V flood zones, walls are not permitted, or they must be designed to disconnect from the structural columns and be carried away with the floodwaters. The goal is to minimize the amount of structure that gets knocked around and damaged by everything in the water.
This is the same reason that FEMA discourages and won’t insure the bottom floor being used as living space, or even storage sometimes. Find space upstairs for storage! (Yes, that’s a big ask in many houses with little closet space.) Modify an attic space by moving the insulation above, and storing items there. If you add a few rooms, make sure the new attic above is able to be used as storage. Have a yard sale for all those things you forgot you saved! And consider hanging up your kayaks, paddle boards, bikes, and trikes from the ceiling of your garage or carport area.
See FEMA’s Technical Bulletin 2 for a List of Flood Damage-Resistant Materials
https://www.fema.gov/sites/default/files/2020-07/fema_tb_2_flood_damage-resistant_materials_requirements.pdf
There are also materials that should and should not be used on the bottom floor. Concrete, concrete block, and terrazzo are able to withstand flooding and dry out and be cleaned afterward. So are fiberglass and plastic materials (siding, window frames, etc) and cement board and tile (showers, floors). Wood depends on how it’s made – solid posts that are chemically treated to be decay resistant (like fence posts) will stand up okay, while MDF (used for cabinets) would warp terribly and couldn’t be completely cleaned. Remember that storm surge or flood water is not potable water – it’s full of salt, sewage, oil and gas, and others – so you will want to clean anything that comes in contact with it. Save the nicer materials for upstairs areas in your home.
Wrapping It Up
So, we live near the water because we love it! Then let’s avoid becoming a statistic and proactively create a safe home that we can enjoy, now and always.
Featured satellite image of Hurricane Nicole on 11/10/2022 courtesy of NOAA.
Design Lines 