What is a Seawall?

Seawalls are a vital aspect of coastal infrastructure, serving as a tool to protect communities and structures against the detrimental impact of waves and storm surges. These man-made structures are erected along coastlines, separating the land from the water, and are specifically engineered to withstand the powerful forces of ocean waves and tides. In this article, we will delve deeper into the concept of seawalls, their types, purpose, construction, maintenance, and examples.

Types of Seawalls

  1. Seawalls come in different types, including concrete, stone, timber, and steel. Outlined below are some informative details regarding seawalls of different types: The commonly used seawalls are made of reinforced concrete and are known as concrete seawalls, whereas stone seawalls are constructed using natural rocks and boulders.
  2. Timber seawalls, on the other hand, are constructed using treated timber, while steel seawalls are made of steel sheet piles. 
  3. The choice of seawall is determined by various factors, including the coastal site, wave intensity, and the relevant environmental rules in the region.

Purpose of Seawalls

The key objective of seawalls is to safeguard against coastal erosion, which has the potential to cause substantial damage to land and property. Seawalls also help protect against storm surges, which are sudden and violent increases in water level due to a storm’s winds and low pressure. In addition to protecting communities and infrastructure, seawalls also help maintain shoreline stability by reducing the impact of waves and tides.

Construction of Seawalls

The construction of seawalls requires careful planning and design. Engineers must take into account factors such as the expected wave height and direction, the water depth, and the underlying soil and rock structure. Seawalls are typically constructed using a combination of heavy machinery and manual labor. The materials used vary depending on the type of seawall and the specific environmental regulations governing the area.

Maintenance and Repair of Seawalls

Maintenance and repair of seawalls are critical to ensure their continued effectiveness in protecting coastal areas. It is essential to conduct routine inspections to detect any indications of damage or wear and tear. Any cracks or fractures should be repaired promptly to prevent further damage. Vegetation growth on the seawall should be controlled as it can weaken the structure by creating a path for water to penetrate. Additionally, regular beach nourishment programs should be implemented to replenish sand in front of the seawall and maintain its effectiveness in mitigating the impact of waves. Finally, environmental considerations, such as the impact on the surrounding ecosystem, should be taken into account when carrying out maintenance and repair work.

Advantages and Disadvantages of Seawalls

While seawalls provide critical protection from natural disasters, they also have their drawbacks. The following are the advantages and disadvantages of seawalls: 


  • Effective protection against coastal erosion and storm surges.
  • Can reduce the risk of flooding and property damage.
  • Provides a solid foundation for buildings and infrastructure in coastal areas.
  • Can be designed to blend in with the surrounding environment and contribute to the aesthetic appeal of the area.
  • Can create recreational opportunities, such as walking or biking paths along the seawall.


  • Can be costly to construct and maintain.
  • May cause disruption to natural habitats, such as wetlands and beaches, by altering natural processes such as sediment transport.
  • Can lead to beach erosion and sand loss in front of the seawall due to wave reflection.
  • May not be effective in extreme weather conditions, such as hurricanes or tsunamis.
  • Can lead to the concentration of wave energy at the ends of the seawall, increasing erosion in those areas.

Examples of Seawalls

Numerous seawalls can be found worldwide, including Japan’s renowned sea walls, Italy’s Venice Flood Barrier, and the Dutch seawalls that safeguard the country against the North Sea. Historical examples of seawalls include the Great Wall of China, which includes sections built along the coast to protect against invasion.


Seawalls are a vital mechanism in shielding communities and infrastructure from the consequences of coastal erosion and storm surges. Despite their pros and cons, they are a crucial component of coastal infrastructure worldwide. With changing environmental conditions, the design, construction, and maintenance of seawalls will evolve to ensure they continue to be effective in safeguarding coastal communities. If you live in the Fort Lauderdale/Miami area, and need help with seawall maintenance, restoration, or a new seawall build, please contact Hollywood Marine Construction!

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