Written by

Sarah Noel

April 5, 2023

Fact-checked by

Tom Grupa

Seawall cost

A seawall costs $150 to $600 per linear foot or $15,000 to $60,000 for the average residential project. Building a seawall in a commercial or high-erosion zone costs $700 to $2,000 per linear foot. A lake seawall or bulkhead for shores without heavy waves is cheaper than walls on ocean coasts.

Seawall repair costs $100 to $250 per linear foot.

• Most new seawalls take 1 to 3 weeks to install.

• Seawalls are mandatory before building a home next to any river, canal, lake, or beach in most places.

• Permits and engineering plans are necessary to build or modify a seawall.

Average seawall construction cost

The following table shows the average cost to construct a 100’ long seawall.

Bulkhead or seawall cost per foot

The cost to build an ocean bulkhead or lake seawall is $150 to $600 per linear foot for vinyl, steel, concrete, or wood.

• A steel, vinyl, or concrete seawall costs $200 to $600 per linear foot.

• A wood seawall costs $150 to $500 per linear foot.

• A riprap rock or boulder seawall costs $50 to $200 per linear foot.

Seawall material requirements vary based on the location:

• Wooden bulkheads are for freshwater installations in minimal-wave areas.

• Bulkheads or seawalls prone to heavy waves often also need additional riprap rocks and boulders installed at the wall base.

• Vinyl seawalls have height limitations of 6’ to 7’ maximum. Taller walls require concrete or steel.

Steel seawall cost

A steel seawall costs $200 to $600 per linear foot installed, depending on the depth, thickness, and site accessibility.

• Galvanized steel seawalls or bulkheads last 25 to 35 years on average.

• Steel seawalls are also known as “sheet pile walls.”

Steel seawall pros and cons:

• Resist water pressure well in a lake’s freeze-thaw cycles

• Require large pile-driving construction vehicles to install

• Rust quickly in saltwater without a protective surface coating

• Little maintenance needed

• No height limits for steel seawalls

Vinyl seawall cost

Installing vinyl seawall panels costs $200 to $550 per linear foot on average. Vinyl seawalls last 50 to 60 years and need little maintenance. Installers typically use concrete on the top for structural and aesthetic reasons.

Vinyl seawall benefits:

• Does not rust, crack, or rot

• Lightweight and easier to install than other materials

• Doesn’t require heavy equipment

• UV-protected

• Often has a lumber, concrete, or steel frame

• Resists damages from marine creatures

Concrete seawall cost

A concrete seawall costs $200 to $600 per linear foot installed. Large equipment is necessary for installation.

• These steel-reinforced seawalls and bulkheads last 30 to 50 years.

• Maintenance to repair holes, cracks, and joint separation is essential to prevent rusting of the internal steel rebar.

Concrete seawall benefits:

• Available as precast panels, interlocking blocks, or custom-shaped forms of curved concrete.

• They are the tallest type, ranging from 10’ to 20’ high.

• Ideal for coastlines prone to the biggest storms.

Wood seawall cost per foot

A wooden seawall costs $150 to $500 per linear foot installed. Wood is best for freshwater bulkheads. Wood rots faster in saltwater and lacks heavy wave resistance.

• Pressure-treated lumber seawalls last 10 to 40 years.

• Timber bulkheads have post-and-plank or tongue-and-groove designs.

Riprap rock and boulder seawalls

A riprap rock or boulder seawall costs $50 to $200 per linear foot, depending on the slope, depth, rock size, and accessibility. Riprap installation includes grading the site and laying a geotextile lining before building the rock revetments. Riprap rocks are typically granite or limestone.

Riprap rock seawall benefits:

• Break waves well

• Easy to install, repair, and refill

• Supports the natural eco-system

• Often used to reinforce seawalls subject to heavy tropical storms

Living shoreline cost

A living shoreline costs $50 to $350 and involves planting salt marsh grasses or installing a structure comprised of oyster shells or granite rock. Living shorelines constructed with bags of recycled oyster shells are cheaper than those made from granite rock.

Living shoreline benefits:

• Reduces wave energy instead of reflecting it

• Naturally protects shorelines from erosion

• Helps restore valuable salt marsh and oyster habitats

• Improves water quality

Cost factors to build a lake seawall or bulkhead

Cost factors in building a seawall or bulkhead include:

• Wall material – Seawall material prices vary depending on if builders use vinyl, steel, concrete, or wood, either with or without riprap rocks.

• Length and height – The taller the seawall required, the more reinforcement material and extra labor it takes to build.

• Job complexity – Labor increases for hard-to-access sites and when contractors must remove obstacles like tree stumps, etc.

• Seawall replacement vs. new construction – Reinforcing an existing seawall costs half the price of building a new seawall.

• Foundation repairs – A failing seawall creates home foundation damages as the soil around the building shifts. In this case, contractors do extra backfilling and land grading.

• Removing old seawall – An old seawall removal costs $50 to $150 per linear foot, depending on the material and location. Builders sometimes reinforce an old seawall or bulkhead instead in places where removals aren’t possible.

• Structural engineering design-plan fees to get a permit cost $2,000 to $3,000 from a certified marine engineer, depending on the project size.

• Permits and regulations – Seawall or bulkhead permits cost $100 to $400 on average, depending on the size and location.

• Freshwater vs. saltwater – Cheaper types of seawalls like wood, steel, and other metals deteriorate quickly in saltwater. Costs increase for seawalls facing the open ocean that must be larger to withstand storm waves and saltwater corrosion.

• Coastal access – Marine contractors building from the water typically need to rent a barge, increasing the labor cost.

• Environmental factors – City laws in coastal areas sometimes require seawalls to be tall enough to withstand the biggest tides and storm surges expected within the next 30 years.

• Soil conditions – Drilling through hard clay or rocky soil costs more in demolition labor and debris-hauling fees.

• Drainage – Properties prone to flooding may need to install another drainage system. A French drain costs $10 to $35 per linear foot.

• Commercial projects & high-erosion zones – Extra-large seawalls cost $700 to $2,000+ per linear foot to build with custom concrete and layers of riprap rock. Known high-erosion zones include parts of Miami, Louisiana, and North Carolina.

• Dock addition – Building a dock costs $3,500 to $20,000 or between $15 and $40 per square foot.

Truline seawall cost

A Truline seawall costs $500 to $1,200 per linear foot installed, depending on the depth and site accessibility. This patented bulkhead system uses a steel-reinforced concrete wall inside a protective vinyl sheet piling system that’s aesthetically pleasing. Truline systems last 75+ years.

Seawall maintenance, repair, and replacement costs

• Non-structural seawall repairs cost $100 to $250 per linear foot.

• Seawall replacement costs $150 to $600 per linear foot for severely damaged sections or seawall failure.

• A seawall inspection costs $200 to $600 per visit, depending on if it includes underwater diving.

Seawall FAQs

How much does a seawall cost in Michigan?

Installing a seawall in Michigan costs $150 to $450 per linear foot on average, depending on the material and site accessibility. Riverside seawalls or bulkheads typically use steel, wood, boulders, or vinyl materials. Only areas with heavy waves use concrete.

What's the difference between a bulkhead and a seawall?

A seawall retains the shore and protects against waves. A bulkhead retains the soil but provides minimal protection from waves. Most people use the terms “bulkhead” and “seawall” interchangeably, despite the building differences.

How long does a seawall last?

A concrete seawall lasts 30 to 50 years on average. A wood seawall lasts 10 to 40 years, depending on the quality and location. A poorly installed or unmaintained seawall often needs repairs after 10 to 20 years.

How deep should a seawall be?

• A lakeside bulkhead or canal-facing seawall should be 3’ to 6’ deep in areas without heavy waves.

• A concrete seawall should be 8’ to 20’ deep depending on the force of the waves, the materials used, and building codes.

Are seawalls effective?

A well-built seawall is highly effective at stopping coastal flooding and shoreline erosion behind the wall. Seawalls and bulkheads also protect natural wildlife habitats behind the structure.

Improper seawall installations lead to these problems:

• Rapid erosion of the beach in front of the seawall

• Gradual sinking of the shoreline and property level

• Lack of natural sand replenishment along the shore

• Groundwater buildup behind the seawall that knocks down the wall

• Seawall failure if the building materials can’t withstand local waves

Hiring a seawall installation or repair contractor

Before hiring a seawall or retaining wall contractor near you, be sure to:

• Ask to see their general contractor’s license and marine contractor certification.

• Pick insured and bonded seawall installers with at least 2 to 5 years of shoreline construction experience.

• Look for members of the International Marine Contractors Association.

• Compare three or more bids from different coastal builders.

• Remember that the cheapest quotes are typically for low-quality work.

• Read their reviews on HomeGuide and Google.

• Request an itemized bid listing all costs involved.

• Use a payment schedule at job milestones instead of paying in full upfront.

Questions to ask

• Do you specialize in seawalls or bulkheads?

• Which wall materials do you offer, and how long do they last?

• How many seawalls have you built around here?

• Can I see your list of references and photos of past projects?

• What’s the most practical seawall or bulkhead design for my property?

• Do you know all the local seawall building regulations?

• Will you pull all permits from the city and environmental agencies?

• Can I review the design plans before the project starts?

• How will you prevent erosion behind the seawall?

• Will the slope of my yard change after seawall installation?

• What equipment will you use, and will it affect my landscaping?

• How should I prepare space for the crew?

• Are all materials and labor fees in this bid? What extra charges can I expect?

• Does the final site cleanup cost extra?

• How should I contact the building supervisor?

• Do you hire subcontractors, and if so, do extra fees apply to manage them?

• What’s in your warranty?

• How long will this construction take?

• What’s your payment timeline?

• Will I get a copy of the contract before work begins?