Beach renourishment is a project which replaces sand (or other sediment) that is lost through erosion, longshore drift, or other reasons. By creating a wider beach with new sand, it becomes possible to prevent future damage to coastal structures. The new sand interacts with the waves in the surf zone to reduce the impact of very high tides, storm surges, and even tsunamis.
The first beach renourishment project in the United States was completed at Coney Island in 1923. It is now used around the world as a way to protect shorelines because of the effectiveness of this process.
Some beaches do not benefit as much from this type of project as others because of their location, the amount of submerged sand available, and other factors that may be present geographically. That is why these beach renourishment pros and cons must be carefully evaluated before beginning this type of project.
List of the Pros of Beach Renourishment
1. Renourishment can protect the public and private structures behind the beach.
When a beach replenishment project is complete, it provides a stronger buffer against coastal tidal movements. Even during strong surges, the sediment reduces the risk of a beach structure suffering a catastrophic incident. Over time, if tidal surges are repetitively strong, the shore ecosystem could eventually collapse. This project keeps the environment stable, which means it continues to support the economy in a variety of ways.
2. It widens the beach to create more usage opportunities.
When a beach is wider, it is usable by more people. That means businesses located at the shore of more revenue earning opportunities available to them. Adding sand reduces the physical hazards that can be found at the beach, create safe habitats for marine life, and reduce the risk of toxins spreading along the coast. When a renourishment project is successful, it can promote higher sustainability levels.
3. A safer environment for the public is created at the beach.
Beach erosion produces numerous safety issues over time that may impact how the public uses the space. Adding new sand helps to prevent sinkholes from forming along the coast. It creates more room to notice jellyfish that may wash ashore which could cause an injury. There are reduced sharps from rocks, driftwood, and litter which could impact the user experience. With proper structuring, a beach renourishment project may even reduce the threat of algae blooms along the shore.
4. The project helps to protect the ecosystem of the shore.
Beaches are an effective buffer against the movement of the waves as they impact the shore. Although there are coordinating protection structures that can help the beach, the nature of sand is that it will erode with any water movement. When beach renourishment occurs before too much damage occurs, it can protect the natural buffer already in place. That protects the coastline from high levels of natural erosion by maintaining or improving the current slope of the land heading out into the water.
5. It develops the foundation for a larger, permanent beach in the future.
When Hurricane Sandy struck the east coast, it wiped out the beach at Coney Island. Since the 1920s, beach renourishment projects have occurred here, helping to save the entertainment area from the fiercest storms that have hit the area over the century. Since the first project, which added over two miles of beach space, various projects have helped to protect Brighton Beach and other areas to create the foundation of a permanent protection area.
6. Beach renourishment can be used to create specific areas of risk reduction.
On Long Island, the Army Corps of Engineers has engineered, then built three different beaches which are intended to reduce the risks of erosion. Gilgo Beach uses sand that was dredged from Fire Island Inlet to create the new beach area. To help pay for the cost of the replenishment activities, entry fees are charged is someone hasn’t purchased a recreational permit to use the area. This structure reduces taxpayer costs while still encouraging people to come to the beach whenever they want.
7. Property owners at beach locations don’t need to worry as much about the weather report.
Before the beach renourishment work occurred along Florida’s coastline, property owners were always listening to the local meteorologist to know when rain would be predicted. They’d need to know how much the Gulf would swell, if their property would be flooded, and if they’d have beach access after the storm. Before the 1990s, even small storms impacted local businesses. Now that most projects are complete, the seawall is no longer seen as the last line of defense for the property. The new sand is now an additional tourism opportunity to enjoy.
8. There are economic benefits available when the project is finished.
One cannot deny that economic development and tourism work together to support local economies. Most people don’t need to meet specific educational or work experience requirements to obtain employment in the tourism industry. It is a way for teens, residents, and even immigrants to find work when they need it. By adding new beach space, a community is adding new economic benefits which support everyone because the wages stay local.
9. It may provide infrastructure benefits to the community.
Most communities today have building codes enforced which require new properties to be a minimum distance away from the shore. These rules were not in place several years ago, which means sewer pipes, power lines, potable water, and other infrastructure items may be close to the shore. Investing in a beach renourishment project helps to protect these prior investments, allowing the community to benefit from their continued service.
10. Beach renourishment supports recreational opportunities.
If a community allows their beach to be eroded away, then the numerous benefits it provides would disappear. Beaches do more than provide a buffer against the waves. It is a place where families head on warm days to enjoy swimming. You can safely go sunbathing when the beach is present. Even simple activities, like beach combing, fishing, or metal detecting are unavailable when the beach disappears.
11. It encourages new vegetation growth when the project is complete.
Beach renourishment projects which include adding new vegetation to the shore tend to be the most successful. When new plants are added to the ecosystem, they help to stabilize the tidal flats. That works to reduce the speed of the incoming waves. The combination of factors helps to slow the process of erosion while creating a new series of habitats for local wildlife. It also works to prevent flooding issues which may have caused the erosion in the first place.
List of the Cons of Beach Renourishment
1. It may be difficult to find materials that are similar to what is at the beach.
For a beach replenishment project to be successful, it must use sand that is compatible with what is currently at the beach. That’s why many projects pump sand from beneath the water’s surface locally. Even though it is wet and may have organic components in it, there is a guarantee of consistency. If the sediment is incompatible, then erosion issues may be enhanced. The correct size and material must be added, whether that is clay, silt, or sand, or the project to be successful.
2. When new sediments are added to the beach, it may bury marine life.
Marine life is adaptive. As the sand is drawn away from the shore, new ecosystems develop near the edge of the shore. Once you start adding new sand, an interruption occurs to the system. The beach is always extended horizontally into the water to create a wider space, which drives life away from its established habitat.
Nature will adapt to the new circumstances over time. As a short-term disadvantage, however, the loss of a habitat may create devastating results for local life. That disruption may continue with ongoing wave pattern changes or other changing shore life patterns which occur.
3. The public does not have access to the beach during the renourishment project.
When a renourishment project is taking place, the beach is no longer safe for public use. The equipment required to bring the sand to the shore, along with the reinforcement structures that are added, can shut down miles of beach all at once. For a business which bases its livelihood on the shoreline for its business, a prolonged restriction could lead to a potential bankruptcy.
Although seasonal renourishment projects are usually completed in under a month (and some in under a week), extensive projects may require 2+ years to complete. Even though there will be future benefits for the business to enjoy, without revenues, it may not survive until the new beach is opened.
4. Most locations require a repeated renourishment application for the work to be effective.
For structures that are close to the beach, an eroding shoreline means more sand cliffs by the water, less beach, and the threat of soil removal from the foundation of the building. Too much erosion could cause some of the properties to no longer be structurally sound. Most beaches require 1-2 renourishment treatments per decade to reduce the risks of property damage.
To enhance the effectiveness of this work, other structures must be added to support the renourishment project. Some beaches require a seawall to halt the water to prevent future erosion. Breakwaters can be installed to reduce wave strength or create jetties where the sand can be trapped. Each additional project comes with an added cost.
5. It is an expensive project to complete.
Beach renourishment offers a meaningful solution for a shoreline which struggles against a strong tide. It helps to stop erosion and prevent new issues at the same time. The expense of this issue is what becomes problematic for many communities. Using Panama Beach as an example, 840,000 cubic yards of sand were added to 4 miles of beach at the cost of $14.5 million in 2017. Six years before, the city added 1.3 million cubic yards of sand at a cost of $15.7 million. Another 3.3 million cubic yards were put in place in 2005 and 2006 at a cost of $23.5 million.
Now apply those costs to each beach which requires renourishment. Most of these projects are government-funded, which means local taxpayers are footing this bill.
6. Adding sand to the beach does not solve the problem of erosion.
When waves crash into the shore, it brings in some sand while taking some away with each movement. There are times when the beach will grow. In some locations, the opposite occurs, as the tides take away more sand than it brings back. Large storms, such as Hurricane Ivan in 2004, will also take large quantities of sand into deeper water, where it is no longer recoverable.
Beach renourishment will supply new sand to the beach, but it won’t solve the erosion problem. The tides and storms will still rip sand away, making many projects a temporary fix to a permanent problem. What protection is provided is often confined to a small area.
7. The work must be completed within a specific time for it to be effective.
Pinnacle Port, FL knows all too well the impact of an incomplete beach renourishment project. During Hurricane Ivan, the beach lost 4 feet of sand. After the storm, the city started a large renourishment project to add 3 million cubic yards of sand back to the beach along a 16-mile stretch. Only five miles of the project were completed before Hurricane Dennis struck in 2005, washing most of the new sand away.
Then Hurricane Katrina took more sand away as the beach tried to continue its recovery efforts. If the work isn’t completed before the next major erosive event occurs, you could lose all the work you just put in to save the beach.
8. There is a high energy cost to pay in addition to the capital cost.
Beach renourishment requires dredging or material transportation. You must then deposit the sand on the beach, then move it to an appropriate location. The entire removal, transportation, and finalization process creates costs which are not always calculated into the final figures of the project. Fuel charges, carbon releases, and potential wave changes caused by dredging all create potential issues which may need to be addressed.
9. Unintended consequences can be unpredictable with beach renourishment projects.
If you dredge the bottom of an offshore location, there is always a chance that you could change how the tides impact the beach. In severe instances, it is possible to change the direction the waves travel when they come close to the shore. When these situations occur, it may resolve an issue at one beach, but then it will cause a new problem at another location. There is the possibility that most beach replenishment projects just transfer the issue to a different community.
These beach renourishment pros and cons work hard to protect local ecosystems. A successful project protects property values, encourages new business opportunities, and better public access to the shore. Because of the cost and time involved in a replenishment project, it may not be suitable to save every beach using this method. That is why this type of work is usually approved by local authorities instead of through national oversight.