Coastal communities across the world are contending with the impact of more frequent extreme weather events, which present unique challenges amid rising sea levels. In fact, the aftermath of a devastating hurricane season last year highlighted the vulnerability of these communities. The results were catastrophic flooding, damage to homes, roads and infrastructure and erosion to beaches and coastal barriers. This leaves communities more exposed, infrastructure more prone to damage and of course there are significant costs associated with recovery efforts and repair.
With early forecasts predicting another relentless series of storms and hurricanes throughout 2025, a need for comprehensive strategies to safeguard against the risk of flooding, erosion and storm surges is becoming increasingly urgent.
Shoreline armoring is one way to mitigate these risks and involves the construction of physical structures to protect shorelines from coastal erosion and flooding. These coastal structures, such as seawalls, breakwaters, and riprap, are designed to hold back the sea and prevent the loss of sediment, while inland shoreline armoring and stormwater management infrastructure help to reduce flood risk for communities in the event of torrential rain.
Shoreline armoring is a sophisticated engineering solution that fortifies vulnerable coastlines through hard, soft and hybrid material solutions. It involves a manufacturing expertise to ensure innovative materials which can withstand immense tidal pressures. The supply of this volume of material also calls for a strong level of expertise as it requires delivery to challenging tidal sites. In some scenarios, it also involves the collaboration of industry-leading hydraulics labs that help stimulate the effects of tides and floods, to ensure optimal performance.
Communities are increasingly looking for resilient solutions that encompass structural improvements, on top of temporary reinforcements like beach nourishment. By investing in a combination of hard-armoring like riprap and soft-armoring solutions like living oyster-reefs that prevent the loss of sediment, communities can build resilient solutions that provide maximum protection during intense weather periods.
Here we take a look at three successful projects that demonstrate the impact of shoreline armoring.
The impact of Hurricane Sandy highlighted a need for enhanced measures to safeguard New York City’s coastal areas against future storms and flooding. Tilcon New York (NY), A CRH Company, was selected to help elevate the East River Park, on the Lower East Side of Manhattan - a significant undertaking requiring nearly one million tons of aggregates.
Scheduled for completion by 2026, the East Side Resiliency Project will see East River Park, rebuilt at a higher elevation, averaging about eight feet (2.4 meters) across its 20 hectares (200,000 m2).
Jointly funded by the City of New York and the federal government, the project, once complete, will help protect up to 100,000 New York residents from future flooding.
Leveraging its extensive fleet of barges to deliver a majority of the material to the site, Tilcon NY is also helping to keep more than 45,000 delivery trucks off New York City’s streets while reducing carbon emissions by 86% compared to conventional trucking.
The 70-year-old Elliot Bay seawall, which protects the Seattle waterfront, was in desperate need of repair, having been ravaged by constant exposure to the sea and several earthquakes. Oldcastle Infrastructure, A CRH Company, was carefully selected to produce 400 immense Z-shaped superstructure segments and hundreds of 20-foot-tall face panels for a new Elliot Bay seawall. The company’s use of high-quality, durable precast concrete allowed for quicker and easier installation, improved constructability, and lowered life-cycle costs.
The Elliot Bay seawall now provides a natural defense for the city during storms, and a recreational space for city residents during calmer weather. But the real innovation lies beneath the surface. When the old seawall was first built, much of Elliot Bay’s existing wildlife habitat was cleared – the sloping beaches, the many crevices and a vegetated seabed in which biodiversity thrived. The new seawall aims to correct this biodiversity loss through the inclusion of a grooved, textured face to promote algae growth and rock beds for fish to hide and forage and in which marine plants can take root. This is a structure that doesn’t just stand up to the elements, but enhances the environment, and helps it endure.
Across the ocean, North Atlantic storms can be particularly fierce too. To safeguard the world-renowned Royal Portrush Golf Club from relentless erosion and the looming threat of rising sea levels, Northstone, A CRH Company, was selected to undertake a vital coastal defense project. The scheme involved the excavation of an adjoining beach and the layering of different high strength materials of basalt and limestone rock, reinforced with geotextiles and sand infill to widen the course by 20-meters, to extend its longevity in the face of destructive waves.
The work also included replenishing areas of the dunes with sand that had been washed away over years, all while coordinating timings within the only working window of the day possible due to changing tides. The result was a fortified coastline and the preservation of the integrity of a course that is consistently ranked among the best in the world.
The urban island of Manhattan, Seattle’s bustling city waterfront and Ireland’s rugged Atlantic shoreline have all benefited from crucial shoreline defense strategies, to prevent the loss of land from coastal erosion and to safeguard valuable real estate from rising sea levels and related flooding. This has proven a credible investment, reducing the long-term costs associated with repair and rebuilding, following a significant event.
Strengthening shorelines fosters the development of resilient communities that can thrive in the face of environmental challenges, and as such it will become an increasingly important priority in the future, as the impacts of extreme weather events become more and more severe.
Communities that act now will improve residents’ safety and quality of life for generations to come.
