Protecting Ebeye from storm erosion and wave overtopping

The challenge: protecting the Marshall Islands from increasingly frequent climate hazards

Ebeye, a small low-lying and densely populated island in the Kwajalein Atoll, was almost wiped out in 1991 by Typhoon Zelda. The storm caused serious damage to water, sewerage, and powerlines – damaging 60% of Ebeye’s buildings and leaving 5,000 people homeless.

As climate hazards become more frequent, the risk from coastal inundation and erosion is growing – and rising sea levels are magnifying the problem. Ebeye needed a coastal defence system to protect its infrastructure and its citizens from the impacts of climate change.

The solution: creating adaptable designs for coastal protection

In 2016, the RMI Ministry of Works appointed Royal HaskoningDHV as the lead designer on the Ebeye Coastal Protection Engineering Design and Construction Supervision project, operating as part of the Pacific Resilience Program (PREP).

Phase 1 of the project required the provision of documentation, including a level of service report, a concept design report, a multi-criteria analysis, design investigation protocols, and a preliminary design report.

As part of our research, we discovered that the ground levels at Ebeye were approximately 0.5 metres lower than previously reported – prompting a new coastal risk assessment. These findings were then incorporated into the coastal protection designs.

We initially developed ten concepts for coastal protection and worked with the RMI and key stakeholders to assess and rank those designs. We then shared our findings with the local community for further consultation, and produced a list of five designs to develop further.

After further refining this list, we came up with three final recommendations which were endorsed by the client and modelled by the University of New South Wales Water Research Laboratory.

Ultimately, a seawall design was determined as the only feasible option to protect Ebeye against storms and rising sea levels.

As part of phase 2 of this project, we’re acting as an expert consultant and supervisor during the construction of the 1.8 metre seawall – providing procurement assistance, design amendments, and risk management services.

The result: storm protection until 2070

Once complete in 2024, the seawall will provide long-term protection up to a sea level rise of 0.5 metres, and mitigate erosion risk on Ebeye’s oceanside shoreline.

The area’s low-lying topography and rudimentary stormwater drainage system means there will still be potential for flooding in the most severe weather events. But the project will significantly reduce the risk of inundation caused by wave action.

It’ll help protect Ebeye well into the future, increasing the island’s resilience to climate events, reducing the risk of damage to housing and infrastructure in the coastal zone, and safeguarding the livelihoods of its citizens.

By protecting and restoring important coastal ecosystems like coral reefs, the project will also preserve rich biodiversity, and provide crucial benefits for food security and tourism. And because coastal design guidelines are limited for atoll environments, the project will also act as a leading example for other nations.