In the guide below, we discuss beach nourishment (also known as beach replenishment).
We outline what it is, how it works, how it might help, and also list some of the potential pros and cons.
What Is Beach Nourishment? (Definition)
Beach nourishment is also known as beach replenishment, and sometimes beach filling.
Beach nourishment is the process of replacing sand (or sediment) that has been lost on beaches (and coastlines).
How Does Beach Nourishment Work?
The key steps in beach nourishment are:
1. Importing sand from another location
2. Spreading or depositing sand across the beach, especially in areas where sand has been lost.
Both berms and dunes can receive imported sand
Methods Used To Source Sand & Sediment
– Offshore Dredging
Dredging vessels can pump sand from offshore locations and deliver it to the beach
– Other Forms Of Dredging
Other locations can also be dredged for their sand, such as creeks
– Sand Backpass Pipelines
An underground pipeline that delivers sand from one location to another location
As of 2021, work was underway on a ‘Sand Backpass Pipeline’ project in Surfers Paradise in Australia
– Reusing Excavated Sand
In areas where regulations allow it, sand from suitable coastal properties that has been excavated and then treated after development of those properties, can in some instances be reused for beach nourishment
What Does Beach Nourishment Do? How Does It Help?
Beach nourishment can help in the following key ways:
– By replacing sand that has been lost from beach and coastal erosion
Erosion can occur in a range of ways, such as from weather, tides and waves, natural events, and so on
– Restoring the recreational and aesthetic value of the beach
Which can also have flow on social and economic effects, both locally, and externally from incoming tourism
We discuss these points and others further down in this guide in the ‘pros and cons’ section.
Beach Nourishment Examples
Beach nourishment has been happening for a significant time now in a range of countries across the world.
You can perform an online search for beach nourishment in your country or city/town for case studies and examples
Pros & Cons Of Beach Nourishment & Replenishment (Advantages & Disadvantages)
Helps Address Beach Erosion
Beach nourishment is one way to help address beach erosion by replacing sand that has already been lost.
May Help Reduce Future Shoreline & Beach Degradation
Beach nourishment can build beaches up so there’s more sand to act as a buffer against future erosion and degradation of the sand and shoreline.
But, some beach nourishment activities aim at widening beaches and shorelines too.
The impact this may have is that it creates a larger beach surface area, and therefore water energy might dissipate across this larger area, instead of focussing more energy on a smaller area.
The end result of this can sometimes be less shoreline and beach degradation over time.
May Help Protect Buildings & Infrastructure Close To Shorelines
By both addressing erosion, and providing a beach buffer against weather, tides and natural events, beach nourishment may play a role in helping protect buildings and infrastructure near or next to shorelines.
Can Have Environmental Benefits
Beaches and coastlines that are maintained may contribute to a healthier marine ecosystem.
Can Have Social & Economic Benefits
When beaches are nourished and replenished, there might be a range of social and economic benefits.
The recreational and aesthetic value of the beach is maintained or increased.
And, there can be flow on effects of a more appealing or ‘in tact’ shoreline, such as people continuing to visit the beach, more tourism at the beach, more economic activity happening at or nearby the beach, and even people moving to live or work in places with more appealing beaches.
May Help Address Illegal Or Damaging Practices
Beach nourishment can help replenish beaches that have been mined for their sand.
This practice is illegal in some countries.
Beach nourishment activities cost money.
There’s the initial cost of dredging, or building pipelines, and then depositing sand on beaches.
But, there’s also ongoing nourishment costs that happen over time too.
Having said this, some groups might say that it’s actually more of an investment than a cost, depending on the net return (economic, social, environmental, and so on) of the replenished beach, compared the costs.
So, costs vs net return on cost has to be weighed up.
Sourcing/Importing Sand & Sediment May Have Potential Issues To Consider
As just a few examples:
– Dredging offshore may impact or disrupt marine life and marine ecosystems in the area where sand or sediment is extracted
– Building pipelines may impact or disrupt coastal marine life and marine ecosystems
– It’s not always easy to find suitable or compatible sand, and, sometimes that sand can be located some distance away, which incurs transport costs and potentially other challenges
Other Options That May Help Preserve Beaches
One option that may help preserve beaches by specifically reducing beach erosion is an artificial reef.
Artificial reefs may break waves and dissipate wave energy further offshore, with the end result being less wave force hitting the beach
Additionally, artificial reefs may also help trap sand and sediments on beaches, as opposed to allowing them to be carried out further to sea
There’s also other options, known as ‘hard engineering’ vs the ‘soft engineering’ approach to beach nourishment explained in the guide above.
Hard engineering involves building hard structures like breakwater structures for example, that help protect or maintain shorelines and beaches in different ways.