The Preventive Methods of Beach Erosion

Our shorelines are rapidly eroding. Damages to the shoreline adversely affect the ocean ecosystems and beachside residents who call this area home. Nowadays, there are numerous techniques, strategies, technologies and planning measures to address beach erosion. Most erosion solutions are directed primarily at the erosion created by wave attack. However, erosion is also caused by wind and storms. Other erosion forces are local and available depending on the site’s geomorphology and geology.Beach Erosion Solutions

Coastal erosion is an important natural phenomenon that can destroy man-made infrastructure, like roads, railroads, harbor facilities, and other buildings. Humans have built structures that stop or slow down naturally occurring erosion for thousands of years. These structures are designed to protect man-made structures and are very diverse: groins, jetties, breakwaters and other components. Let’s go over some of these structures and see how they work:

Groins

Groins look like long walls that are built alongside beaches. These erosion solutions are very simple to build and manage. They are very effective against beach erosion. They are built of stone rip rap, timber pilings or steel sheet pilings, depending on the force of the erosion process. They act as physical barriers against currents along the shoreline. They control and manage the sand movement, but also the force of the waves, especially for longer periods of time. The longshore current will lose a lot of force and velocity when hitting the groin, causing it to dump part of its sand load on the up-current side of the groin. This helps build up the adjacent beach, stopping and slowing down erosion. As the current passes the groin (if it’s not designed properly), it picks up additional sediment from the down-current side of the groin. This phenomenon causes local erosion. Although groins are very effective to fight beach erosion, there are multiple drawbacks to this technique. While some beaches are protected and receive sand, other beaches may lose too much sand. This domino effect process is one of the main downsides of groins.

Breakwaters

Breakwaters are simple barriers that are placed offshore to protect parts of the shoreline. They are placed in the water, several hundred feet from the coastline. They act as breakers for waves (hence their name) and will protect the beaches from erosion. This whole process allows the beaches to actually grow and gather more sand. The powerful sea or ocean waves are broken on these barriers and the longshore currents bring sand on the beach behind the breakers. Breakwaters can be either fixed or floating, depending on the local factors and what is needed. The breakwaters are very effective erosion solutions that protect beaches, but they can be problematic in certain areas, where the shoreline may be too damaged by the accumulation of sand.

Jetties

Jetties are perpendicular structures built across the shoreline, extending into the ocean or the sea. These beach erosion solutions are made of steel, concrete, stone or timber, depending on the local needs. They are designed mainly to stop sand from accumulating into a ship channel. This is designed in order to stop the channel from becoming too shallow over time (if a channel is too shallow, the ships can run aground). Jetties are often used for each side of the channel. Jetties are also very effective when it comes to beach erosion. Sand that is built up near every jetty can be moved and redistributed along the beach line, helping the beaches grow. These structures also stop storm waves from entering protected channels and littoral drift. The downsides of jetties are sand starvation (when sand simply doesn’t accumulate, caused by a change in currents) and the retreat of the shoreline on the downdrift area.

Here are some products which can help provide successful Beach Erosion Control:

Erosion Control Mats

These beach erosion solutions are an option for virtually every area that has sand beaches. The mats are designed to further the growth of vegetation, which helps stabilize the sand and the soil near the shoreline. The mats can be used to stabilize the area until plants, trees, and roots can grow in the area. The mats are made of natural fibers, like coir, wood fibers and straw. All materials are biodegradable and long-lasting.

Breakwater Tubes

These are designed for long, extended and demanding support for erosion-sensitive shoreline support. The tubes act as simple anti-erosion tools. They are the first line of defense against waves, especially as they break along the shore and the beach. They allow the beach to naturally gather and retain sand, thus helping the long-term deterioration of the shoreline. Breakwater tubes are made of sturdy biodegradable materials and have a long service life.

Geotextiles

These are used for retaining walls, rip rap walls or larger structures that need more protection against waves and wind. The geotextile membrane is used under these structures and will help increase the strength and the stability of the system. Due to the heavy nature of these systems, the most important and often used fabric is woven geotextile.

Coconut Fiber Logs

These are natural tools for coastline protection against erosion. They are designed to be placed alongside beaches that need protection. They are placed on multiple levels, according to the height of the beach or cliff that needs protection. Logs can be implemented in sand dunes (against wind erosion) and in revegetation areas in order to help establish roots and plant growth.

Earth Barrier Walls

Have you ever seen walls made of sandbags near waterways and rivers? Earth barrier walls are excellent beach erosion solutions for the stabilization of coastal areas. They are deployed rapidly and work excellently in virtually every area prone to erosion. They are sustainable as a leave-in-place or as a temporary solution in areas affected by floods. They are designed to be placed on dunes, shorelines, beaches and can be used to protect residential and commercial properties along the beach. They provide a solid defense against incoming tides and wave action. The bags are usually filled with sand in order to make them a solid beach infrastructure component.