Building a seawall costs $25,000 on average, with a wide range between $10,000 and $100,000, depending on the size and type of seawall.
Have you ever dreamed of living on the coast and wondered: how much does it cost to build a seawall? With an average cost of $25,000 and a range from $15,000 to $60,000, seawalls are an expensive but often necessary project for houses on the water. Expect to pay $100 to $800 per linear foot, with more complex projects sometimes reaching $2,000 per linear foot—or more.
Homeowners who need a seawall quickly discover this is a project where professional input is a must. The type of seawall you build is more determined by the soil type and water characteristics where the seawall would be installed, so in many ways, you don't have a ton of options when it comes to material.
Seawall type | Cost per linear foot |
---|---|
Vinyl | $200–$600 |
Steel | $250–$700 |
Concrete | $200–$800 |
Wood | $150–$500 |
Riprap | $70–$200 |
Because seawalls are often priced in linear feet, the size of the wall is one of the largest factors in the total price. The thing about seawalls is they're rarely built in a portion of the property, but rather encircling the entire yard or at least the side that's up against the body of water.
It's not only linear feet that factor in either, but the height of the wall as well. A seawall can be anything from four or five feet high to 15, 20, or more. This depends on your soil type and how deep the water is adjacent to your property, as well as the level of access the crews have when building the seawall.
Seawall Size in Linear Feet | Cost for Wooden Seawall | Cost for Concrete Seawall |
---|---|---|
100 | $15,000–$50,000 | $20,000–$80,000 |
150 | $22,500–$75,000 | $30,000–$120,000 |
225 | $33,750–$112,500 | $45,000–$160,000 |
300 | $45,000–$150,000 | $60,000–$240,000 |
700 | $105,000–$350,000 | $140,000–$560,000 |
Calculating the cost of a seawall contractor can be challenging; for larger jobs like this, you’re typically quoted a single amount, which includes all materials, labor from various contractors and engineers, and equipment. In general, expect labor to cost between $40 and $100 an hour, but up to $300 an hour if the project requires the operation of heavy equipment, such as bulldozers and cranes.
Building a seawall isn’t a job for your average DIYer. Make sure the professional you hire is a licensed building contractor—ideally, with a marine contractor’s license. You’ll also need to contact a local structural engineer or team of engineers to assess the site and design the wall before work can begin.
Where you live greatly impacts the cost of building a seawall. Local codes may dictate different depths for seawalls in different locations, and the cost of materials and labor varies across different regions as well.
In general, saltwater seawalls cost twice as much as freshwater seawalls. That’s because:
Saltwater seawalls require more durable (and more expensive) materials that can withstand saltwater corrosion.
Tidal changes in the ocean mean you may need to build your seawall taller.
Permits for ocean seawalls are generally more complicated (and more expensive) than they are for lake seawalls.
Building a seawall requires a lot more preparation than even some large construction projects. If a seawall fails, its soil can drain into the water and destroy the foundation of a house close to the wall. It's also possible that the water rises beyond the seawall and causes water damage directly.
Some of the costs associated with that prep work include a site survey, permits, an environmental impact assessment, and design work by a structural engineer.
As part of the site survey, your team of engineers and marine contractors will analyze the type of soil and its density. They’ll also monitor high and low tide levels over at least a month and measure the distance between the property and the proposed location of the seawall.
This will be baked into the overall cost of building a seawall, but expect to be charged if you have the survey conducted but don’t move forward with the project or that contractor. Though this can vary significantly, a typical land survey costs between $800 and $5,500; a site survey for a seawall is much different from a traditional land survey, but this is a good frame of reference.
Like any large project, building a seawall must be approved by your local government. Seawall permits are complex so this should be done with a professional. There will likely be several inspections before your municipality approves the permit. This legal permission from the city will cost between $150 and $2,500.
Building a seawall can have negative effects on the coastal area where it’s constructed, including the elimination of tidal habitats and increased erosion of other beach areas. You’ll need to get an environmental impact assessment. These can cost anywhere from $2,000 to $15,000—or even more for larger, commercial projects.
Designing a seawall requires a very specific type of knowledge. You’ll need to hire structural engineers who understand soil mechanics and conditions to design an effective seawall. Engineering firms will vary in what they charge for this service, but don’t expect it to be cheap—and don’t have someone without this background design your seawall instead.
If there's one important point to drive home here, it's this— don't build a seawall yourself. The amount of money that you would spend on materials would still be quite high. Unless you have experience in land surveying and large-scale construction, you'll probably end up spending more trying to DIY this project and hiring a local fencing professional to fix it than you would have if you had just hired the professional in the first place.
Building a seawall isn't an easy DIY project; it takes serious investment and expertise. It also requires specialized equipment, which will cost you a large amount to rent but would be included in a professional's quote. Unless you have experience with these types of projects, you likely won't get past the permit stage.
Replacing an existing seawall is even more challenging—and more expensive—than installing a new one. That’s because you’ll need a structural engineer with a marine background to assess the damage before a marine contractor can carefully remove the old seawall and install the new support structures for the replacement seawall.
Whenever possible, repair an existing seawall instead of replacing it. Repairing a seawall can also be costly, but unless the damage is extensive and hardly salvageable, it is worth it to repair instead of replace. In general, replacing a seawall costs 80% more than repairing it.
Building a seawall is an expensive process, and while there are some projects where you can cut corners, this isn't one of them. Even for smaller seawalls, there are extreme forces to consider so that the walls are built within the safety and structural parameters an engineer designs.
You could save money if you have clearance to build a wooden seawall and want to use reclaimed materials or if you have the option to choose materials, you could go with something less expensive like vinyl. Seawall construction is complicated but you might be able to save some money if you hire a contractor during a slower period of the year or when they have a gap in their calendar.
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A seawall protects coastal areas (or your property and house) from water damage and tides. The wall doesn’t just rebound the waves, but it absorbs and dissipates wave energy. For some homes, it’s a requirement, while others may simply want to build closer to the water. You may have more options for calm freshwater, but seawater requires strong material like concrete or riprap.
The length of time it takes to construct a seawall depends on the size and material; commercial seawalls tend to be much more extensive and thus take longer to build. Expect the actual construction to take between a few weeks and a few months, but the preparation before work even begins might take just as long.
When seawalls are built correctly, they can last over 30 years, sometimes closer to 100. The construction material matters (steel and wood have a much shorter life span than concrete), but the force of the water, how much debris it carries, whether it's saltwater or freshwater, and other factors can all significantly shorten the life span of a seawall.
The most effective seawall is the one that contains your soil, prevents water damage, and properly redirects wave energy. This is often a concrete wall, but riprap and wood are common alternatives. You need to work with a specialist because hydrodynamics and structural forces are extremely complicated, and while you may think you want a wooden seawall for aesthetic purposes, the only one that might work is concrete. A fencing pro can determine which type you need.
Seawalls don’t require a lot of maintenance, but there are some things you (or a professional) should either check or perform periodically. A visual inspection comes first, followed by cleaning of any plant growth that’s attached itself to the wall. You may need to remove debris if it becomes lodged in the wall. The type of seawall that requires the most maintenance is a wooden wall, and you’ll need to make sure any treatment done to the wood is still working as intended.