“The Importance of Beach Restoration and Renourishment Projects”
Beach erosion is often overlooked. However, its significance should not be disregarded. Living near the coast requires professional guidance in order to prevent actions that exacerbate erosion. One popular solution to an eroding coastline is seawalls. These hard stabilization structures may slow or stop erosion behind them. While at the same time accelerating it on sandy beaches themselves.
1. Sediment Removal Beach Erosion
The ocean’s beaches are constructed by sediment carried from rivers and deposited during floods. If these beaches are unprotected by seawalls and jetties. Erosion will gradually wash away their materials and remove significant portions each year. Although the loss of sediment itself does not pose any immediate threats to coastal ecosystems. Beach erosion is a natural process driven by tides and winds.
However, intervention can accelerate it significantly.
To protect their homes. People often build seawalls or narrow strips of land jutting into the water (groynes) which reduce erosion by slowing or stopping its movement in front of these structures. Unfortunately, their footing scours may accelerate the erosion of sandy beaches further still. Dredging activities can contribute significantly to coastal erosion by extracting sediment from beaches. Dredging can alter the shape and flow of waves.
Potentially disrupting habitats while making beaches less stable due to reduced amounts of sediment available for wave-absorbing sandbanks. Sand replenishment projects may help address some of these problems. Though even these efforts cannot make up for the fact that coastal shorelines around the world are receding as sea levels rise. Reassessing how we live along the coast and forming more effective partnerships with nature are the keys to dealing with erosion-related challenges. Some coastal communities have taken to experimenting with “eco-centric” responses to erosion.
This means people moving inland from the coastline and leaving it open to natural processes like sea level rise and erosion. This may mean moving buildings onto higher grounds, or potentially abandoning beaches altogether. Though this strategy may seem radical. It may be necessary if erosion threatens both communities and economies alike.
2. Flooding and Beach Erosion
Erosion has long been an issue on Earth’s land masses. Unfortunately, its severity becomes much more of a concern for people living near coastlines. Erosion eats away at coastlines slowly but steadily, undermining the foundations of homes and leading to flooding that endangers lives and threatens safety. Home and road flooding can also interfere with transportation. Making it hard for residents and workers to access important documents and facilities.
Although often overlooked on a national scale.
Flooding has apparently become an increasingly critical problem in coastal regions across the US.
As sea levels rise, they will bring water into communities that currently don’t experience high tides that impact daily life. While the focus is more on droughts and wildfires than rising sea levels. It may become more of an issue. If a community experiences erosion. Taking action may include building hard shoreline protection measures. Like seawalls or revetments to slow or stop it.
However, such structures may only delay or stop further erosion; in fact, they could even worsen it by interfering with the natural flow of sediment along beaches.
Soft shoreline protection methods offer an ideal solution. These strategies include marsh plantings, sand filling, and using stone sills to trap or add sand. The optimal technique depends on site conditions but usually, multiple strategies will be combined to protect a section of the coast that’s vulnerable. The purpose of beach protection measures is to reduce structural erosion on beaches by decreasing the gradient in net littoral drift (longshore wave-driven sediment transport through the surf zone). To accomplish this task, proper protection measures need to be placed at specific locations and utilized accordingly.
3. Sea Level Rise
Sea level rise poses a major threat to coastal communities. It can accelerate erosion, disrupt animal and plant habitats and intensify storms. Possibly rising due to climate issues. When ocean water becomes warmer, it expands, pushing up against land surfaces and raising sea levels. Other factors that affect sea levels may include slowing Gulf Stream currents, sinking land, or glacier melting.
Beaches erode because sand supplies cannot keep pace with losses to the sea.
Most of the sand that reaches beaches from rivers and streams originates in the land. However, dams block most of these channels, preventing new sources of sand from reaching our beaches. Although waves may move some existing sand around. This merely represents redistribution rather than new arrivals. Destruction of natural barriers such as coral reefs, marshes, and sand dunes hastens erosion as their removal dissipates much of a wave’s energy before reaching shore.
Seawalls, jetties, and groins have caused much erosion by blocking waves from hitting the beach and damaging homes or other structures.
By stopping their natural flow from the ocean to the beach. Seawalls obstruct its natural replenishment process leading to loss of sand due to erosion. Coastal plants serve as natural barriers against erosion. Their roots absorb wave energy by anchoring soil, while also helping absorb water that would otherwise be washed away by waves. Our beaches depend upon coastal vegetation as a safeguard that allows wildlife as well as people access and enjoyment of its beaches.
As our climate alters, sea level rise will have a dramatic impact on coastal environments. Some areas could experience flooding more frequently. While others could lose entire locations altogether. It is therefore crucial for these coastal regions to prepare now for such changes by devising plans to adapt accordingly.
4. Water Supply
Erosion can be a significant nuisance for homeowners living on beachfront properties. Erosion eats away at the foundations of houses. Potentially leading to leakage or structural damage. Erosion can rven reduce beach space. Disrupting recreational activities and wildlife habitat.
It also disrupts waterways and can create flooding problems in towns.
Furthermore, it poses serious business concerns when roads become impassible due to erosion. Potentially wreaking havoc on infrastructure such as power lines and sewer systems. Leading to costly repairs and maintenance expenses. Beach erosion is typically the result of storms, rising sea levels, and changes to sand availability. It may also be compounded by structures like seawalls, groins, and revetments.
Seawalls, typically composed of concrete or steel, can help reduce erosion by stopping tide currents and trapping sand behind them. While they do work, in certain circumstances. They can produce just as severe erosion as natural forms; and may eventually erode back into the ocean or collapse against other structures. Vegetation can be used as a more effective solution. Particularly in combination with hard protection systems like stone sills.
Vegetation helps stabilize dunes by slowing sand movement while protecting homes. Hard protection such as stone or cobble may then be added under this rehabilitated vegetated dune to stop further erosion. Groins are long, wall-like structures that protrude into the ocean from beaches and extend out into the sea. Constructed of stone rip rap, steel sheet pilings, or timber pilings. Their purpose is to stop tidal currents while trapping sand behind them.
While up-current side of the groins allows some sediment load from currents to be dispelled onto adjacent beaches. As the down-current side still experiences erosion. For more information this subject check out this video here
Provided by Antonio Westley
Disclaimer: This article is meant to be seen as an overview of this subject and not a reflection of viewpoints or opinions as nothing is definitive. So, make sure to do your research and feel free to use this information at your own discretion. For educational purposes only.