5 Key Benefits of Modern Dredging for Coastal Protection

The ocean is a source of economic prosperity and natural beauty, but it also poses a threat to coastal communities. Rising sea levels, storms, and erosion put our coastlines under pressure. To protect our shores and infrastructure, we need effective solutions.

For centuries, dredging was used to maintain shipping channels. Today, the practice has evolved. It is a key tool in coastal protection and environmental enhancement. With advanced dredging technologies, we can defend our coastlines and restore valuable habitats.

At Rock and Reef, we use modern dredging techniques to deliver sustainable coastal protection. This guide explores the five main benefits of modern dredging and how it helps secure a safer future for coastal communities.

1. Enhanced Coastal Resilience and Flood Prevention

One of the most important benefits of dredging is its ability to improve coastal resilience and prevent flooding.

Deepening and Widening Waterways Over time, rivers and channels fill with sediment in a process called siltation. This buildup reduces the depth and width of a waterway, restricting its ability to carry water. During heavy rainfall or a storm surge, these constricted channels can be overwhelmed, leading to floods.

Modern dredging techniques remove this sediment, restoring the waterway to its original capacity. By deepening and widening channels, we create more space for water to flow, reducing the risk of it overtopping its banks. This is critical in low-lying coastal regions vulnerable to flooding.

Creating and Reinforcing Natural Defenses Dredging can also be used to create and reinforce natural coastal defenses. Dredged material can be placed to create or strengthen sandbars, shoals, and barrier islands. These features act as the first line of defense against storm surges and high waves, absorbing their energy before they reach the shore.

This approach of “working with nature” uses dredged material to build upon the natural systems that have always protected our coastlines. It provides effective flood protection and helps preserve the natural character of our coastal zones.

2. Beach Nourishment and Restoration

Beaches are vital economic assets and natural defenses. They attract tourists, support local businesses, and protect property from the sea. Many beaches, however, are eroding. Modern dredging offers a solution: beach nourishment.

The Process of Beach Nourishment Beach nourishment is the process of adding sand to an eroding beach to widen it. The sand is typically dredged from an offshore location, like a sandbar or navigation channel. The sand is then transported to the eroding beach and placed on the shore.

This is a beneficial use of dredged material. Instead of being disposed of, the sand is repurposed to restore a natural asset. Modern dredging and survey techniques allow us to find sand that matches the native beach material in size, color, and composition. This ensures the nourished beach looks and behaves like a natural beach.

The Benefits of Wider, Healthier Beaches The benefits of beach nourishment are numerous. A wider beach provides a larger recreational area, which can boost tourism and the local economy. It also provides a better buffer against storm waves, reducing the risk of erosion and property damage. Restoring eroding beaches also restores vital habitats for birds, turtles, and other wildlife.

A Sustainable Solution Beach nourishment is not a permanent fix. Beaches are dynamic, and erosion is a natural process. A nourished beach will erode over time, and periodic re-nourishment will be needed.

However, as part of a long-term coastal management plan, beach nourishment is an effective strategy. It is a soft-engineering approach that works with natural processes. Unlike hard structures like seawalls, which can worsen erosion in nearby areas, beach nourishment helps maintain the natural flow of sand along the coast.

3. Ecosystem Creation and Habitat Restoration

The benefits of dredging extend beyond shoreline protection. Dredged material is now being used to create and restore coastal habitats, such as wetlands, marshes, and oyster reefs. This practice allows us to not only protect our shores but also improve their ecological value.

Building with Nature The idea is simple: by placing dredged material in shallow coastal waters, we can create the foundation for new habitats. For example, dredged mud and silt can be used to raise the elevation of a submerged area so it can support salt marsh vegetation. Sand can be used to create new islands that provide nesting areas for coastal birds.

This approach is often cost-effective because it makes use of material that would otherwise be discarded. It is also scalable, allowing for the creation of large areas of new habitat in a relatively short time.

Benefits of Coastal Habitats The creation of coastal habitats has a wide range of benefits. Wetlands and marshes act as natural filters, improving water quality by trapping sediments and pollutants. They also provide critical nursery habitat for fish and shellfish, supporting commercial and recreational fisheries.

These habitats are also effective at reducing wave energy, providing another layer of protection against coastal storms. A healthy salt marsh can significantly reduce wave heights, lowering the risk of coastal flooding and erosion.

4. Economic Benefits and Sustainable Development

Protecting our coastlines is an economic necessity. Our coastal zones are home to major ports, tourist destinations, and a large part of our population. Using modern dredging to protect these areas is an investment in our long-term economic prosperity.

Supporting Commerce One of the most direct economic benefits of dredging is maintaining ports and navigation channels. If ports are not regularly dredged, they can become too shallow for large container ships, disrupting trade. By ensuring channels are deep and wide enough for modern vessels, dredging supports the efficient movement of goods, reduces transportation costs, and keeps our economy competitive.

Protecting Coastal Investments The economic benefits of dredging for coastal protection are just as significant. The value of property and infrastructure in coastal zones is high. By protecting these assets from erosion and flooding, we avoid billions of dollars in potential damages.

As mentioned, coastal protection projects like beach nourishment offer a strong return on investment. By investing in a wider beach, a coastal community protects its homes and businesses and enhances its primary economic asset: its shoreline. A well-maintained beach attracts tourists, boosts property values, and supports a thriving local economy.

5. Improved Water Quality and Environmental Remediation

In addition to coastal protection, modern dredging can be a tool for improving water quality and cleaning up contaminated sediments. This is important in urban and industrial coastal zones where water quality is often poor.

Removing Contaminated Sediments Over decades, many harbors and rivers have become sinks for pollutants like heavy metals, pesticides, and industrial chemicals. These contaminants get trapped in bottom sediments, where they can pose a threat to human health and the environment.

Environmental dredging can remove these contaminated sediments. Using specialized equipment, the material can be excavated with minimal disturbance. The dredged material is then taken to a secure facility for treatment and disposal, permanently removing the pollutants from the ecosystem.

Enhancing Water Circulation Even without toxic contaminants, the buildup of fine sediments can harm water quality. An accumulation of mud and silt can restrict water circulation, leading to stagnant, low-oxygen conditions. This can create “dead zones” where aquatic life cannot survive. By dredging these sediments, we can improve water circulation and increase dissolved oxygen levels, creating a healthier environment.

Conclusion: A Powerful Tool for a Changing World

The challenges facing our coastlines are significant, but modern dredging offers a versatile tool to meet them. It can help us protect our shores, restore ecosystems, support our economy, and build a more sustainable future.

Realizing these benefits requires more than technology. It requires a collaborative and forward-looking approach to project planning. At Rock and Reef, we are committed to this approach. We believe that by working together, we can use the power of modern dredging to create a future where our coastlines are not just protected, but thriving.