There’s nothing quite like living along the coast. The beach offers an appealing view, and the salty sea breeze can be a crisp addition to your daily life. While there are plenty of sights to see, you may have noticed a number of seawalls near bays or canals, protecting the surrounding land as waves crash against it.
What purpose do these seawalls serve, and why might they be necessary? Below, we’ll address everything you need to know about seawalls. We’ll talk about what seawalls are, why they’re important, what they’re made of, and what kind of maintenance is involved.
What Is a Seawall?
A seawall provides something of a defense for canals and bays. Seawalls minimize the eroding impact of the ocean waves and reduce the waves’ energy to protect the nearby land and its inhabitants. Essentially, seawalls redirect the waves back to the sea, curbing potential damage and erosion over time.
There are two different seawall types: vertical walls and riprap embankments. Each does the same job in a different way, but one option may be more suitable than another in a particular situation.
Vertical seawalls are fairly easy to construct, and they can adequately deflect wave energy to protect the coastline. Essentially, they’re upright, sturdy walls that block waves from damaging the coastline. To make the walls more effective, piles may be installed in front of the wall to diminish the wave energy a little and curtail the impact of the wave.
Riprap embankments, or revetments, are great for low-impact areas, and they’re rather cheap. They don’t do well against heavy waves, but they can break up the wave energy of a small wave, lowering the erosion impact of the wave and protecting the coastline.
A riprap embankment basically starts with a rubble mound, and the side of the mound exposed to the sea is covered in porous rocks, sandbags, or stones. Sometimes, riprap embankments can be made from other materials, like concrete rubble leftover from paving or construction demolition, but the most commonly used materials are stones like granite and limestone.
Why Might Seawalls Be Necessary?
As mentioned before, seawalls reduce the energy of the waves, thereby minimizing erosion and damage along the surrounding area. If left unchecked, churning waves can slowly eat away at the landscape or cause flooding. When there’s enough erosion, waterside structures can easily be put in danger and become subject to collapse or corrosion. And if the area floods, these buildings and the residents are at an even greater risk.
Seawalls essentially protect structures and pedestrians from the harmful effects of waves. Seawalls can also minimize the consequences of heavy waves in storms and hurricanes, and if they’re big enough and strong enough, they can offer a fairly sturdy defense against tsunamis.
For instance, the Indian city of Pondicherry has a nearly 300-year-old seawall that stands 27 feet above sea level in some areas. This same barrier successfully protected the city from a tsunami in 2004 that towered 24 feet above high tide.
What Are Seawalls Made Of?
Most of the time, seawalls are made out of concrete. Concrete creates a strong structure for a decent price, but seawalls can also be made with wood, aluminum, vinyl, fiberglass composite, and—in the case of mound seawalls—sandbags. However, the type of material used can depend on the area and the average power of the waves. Additionally, depending on the contractor you use to build the seawall, you may have other options available as well.
Do Seawalls Need to Be Maintained?
Since they face the harsh roll of waves on a daily basis, seawalls do get a little wear and tear over time. For example, while vertical seawalls can effectively deflect waves, the abuse can cause damage over time. The seawall will need repairs to the front of the structure every now and then.
Riprap embankments will also sustain damage eventually, as rough materials can scrape up against the side of the revetment and crumble bits of the wall away. Also, because mound seawalls aren’t as solid as concrete walls and because they are a temporary solution, they may require quite a bit of time and effort to keep them in decent condition. So, for every seawall, expect necessary maintenance and repairs.
Seawalls can be quite beneficial, and if they’re properly engineered and constructed, they can last for some time. When you need a seawall installed, be sure you trust in the right professionals. At Abbots’ Construction, we take pride in providing quality work and accommodating service.
We can build a concrete, vinyl and composite, or wood seawall to protect your property and other structures. Before construction, our knowledgeable team can take a look at the area and recommend the best option for your situation. If you have any questions about our seawalls, we can walk you through the process to help you better understand this structure.