A day at the beach is nice to have. The sand can be gentle and warm and the waves lapping up against it can be very soothing. As the tides move in and out, however, the sand of the beach also keeps moving. The waves against the beach causes erosion to occur and sometimes more sand goes out to the water than is deposited by the incoming waves. This is when beach renourishment occurs. It replaces the sand that has been removed, but it doesn’t stop the erosion process.
Here are some of the pros and cons of this process.
The Good: It Keeps a Recreational Beach Intact
Beach renourishment often happens on popular recreational beaches. The new sand allows for people to continue enjoying the beach, even with the erosion process going on, and life stays relatively normal. This sand also acts as a buffer for any structures that might have been built on the beach. Erosion can quickly threaten those structures, so the renourishment process adds safety to the beach experience as well.
That safety includes the elimination of hazards that could be found in degraded sand. It isn’t just pebbles that the sand protects against. Instead of the debris that can be left by a seawall or changes in the patterns of the waves that rip-rap can cause, beach sand provides a gentle buffer that helps to keep the environment very natural.
The Bad: New Sand Erodes Very Quickly
The natural sand at a beach is rather compact and dense because it is exposed to the local conditions on a regular basis. New sand, however, is not as compact. It can’t be, because otherwise it would be difficult to transport to the nourishment location. Because it is much looser, it will also erode much more quickly. Beach renourishment, on average, erodes 3x faster than regular beach sand.
It is also incredibly expensive to perform this task. To create a mostly permanent beach renourishment, it can easily cost taxpayers upwards of $100 million. Wider beaches tend to last longer, so the goal is often to extend the size of the beach into the water. This creates a construction zone which not only makes it difficult to use the beach, but can also alter the natural environment and hurt marine life that calls the area home.
Beach sand from a different location is often a different size than the natural beach sand that is already at the renourishment location. Different sizes in sand grains can cause different patterns of waves that may alter the entire eco-system of the beach. Not only will it change the shape of the beach over time, but it will also influence how the beach itself can be used.
In specific circumstances, beach renourishment can be a good thing, but only if it is funded approximately and has a good engineering plan. Sometimes nature demands change and it can be good to go with the flow.