How Much Does a Seawall Cost?

Average Seawall Costs

Seawall Cost Per Foot

Seawalls cost $150 to $800 per linear foot for the average residential project. Some homeowners report costs upwards of $1,200 per linear foot, over 10 times what most retaining walls cost. Commercial and complex residential projects tend to run in the $650 to $2,000 per linear foot range. Dock installation costs push the per linear foot price to the higher end of the range.

Freshwater lake walls cost far less than coastal projects for various reasons, including the lack of tidal change and no saltwater corrosion. Coastal prices vary by state, usually due to locally regulated building requirements.

Vinyl Seawall Cost Per Foot

Vinyl seawalls cost $150 to $250 per linear foot for a five-foot-tall wall. Some coastal areas call for eight-to-10-foot walls, nearly doubling the cost. Vinyl doesn’t corrode and can last 50 to 80 years with little maintenance. Builders often use concrete across the top for both aesthetic and structural reasons.

Steel Seawall Cost Per Linear Foot

Steel seawalls cost $250 to $500 per linear foot. Because of the competitive price and durability of vinyl, most contractors recommend vinyl capped with concrete versus a steel wall. Plus, steel lasts about half as long because it corrodes and eventually fails.

Other Seawall Material Prices

Lake Retaining Wall Cost

A lake retaining wall costs anywhere from $50 to $250 per linear foot. You find lake wall bulkheads are an easier and cheaper project than their coastal cousins. They aren’t as tall and don’t need to contend with tidal fluctuations. They also fare better with steel and aluminum since metal doesn’t corrode as quickly in freshwater.

Seawall Construction Cost Factors

Seawall construction fees vary from place to place and state to state. Some of the main cost factors include:

• Material choice: You’ll pay more for steel or concrete than you will for vinyl or riprap (rocks).

• Local permits and regulations: Permit fees and regulatory processes for seawalls vary from place to place, causing increased pricing, particularly in areas of Florida and Texas.

• Freshwater or saltwater: Not only will saltwater corrode many types of seawalls, but you also need to build high enough to account for the tidal variations in sea level. Two issues not present at inland lakes.

• Access and coastal ground makeup: Prices vary between sandy and rocky coastlines and inland lakeshores. Coastal areas tend to cost more, but variations in the earth works needed from location to location along with regional building codes might mean your project costs twice as much as your neighbor half a mile away.

Build a Seawall Yourself vs. Hire a Pro

In some places, you can install a seawall yourself, but you’ll end up spending almost as much to DIY the job as you would to hire a contractor since you have to purchase the materials, rent the equipment and get the permits. Done incorrectly, you’ll need to the project repaired or replaced, costing more than hiring a pro to begin with.

Some locations don’t allow this as a DIY project, so check with your local code enforcement office or a local boat and water dock contractor. Marine contractors specialize in seawalls, docks, and other structures that need to stand up to the specific challenges of a marine environment. If you do decide to DIY, always hire an engineer to help design it since these structures bear loads and protect from wave action.

FAQs

How long does a seawall last?

Seawalls last anywhere from 10 to 70 years or more, depending on the material it’s made from.

• Vinyl with concrete caps: 50-60 years

• Poured concrete: 50-60 years

• Steel and Aluminum: 30-40 years

• Wood: 10-25 years

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

Both a bulkhead and seawall hold back the soil behind them from erosion. However, only seawalls are designed to protect the shore from wave action. You’ll generally find bulkheads in inland areas or along a protected shoreline that sees no waves.

How deep should a seawall be?

A seawall’s depth varies from four to 10 feet or more, depending on various factors. You don’t need to drive inland walls as far into the ground. Different materials require different depths. Local building codes vary from location to location.