A tailored approach to protecting North Java’s coast

As North Java’s coastlines face risk, President Prabowo pledges a Giant Sea Wall. But what if a more resilient blend of strategies is needed? We recently worked with Deloitte, Witteveen+Bos and Foresight Works to offer unique, comprehensive strategic guidance to coastal protection across North Java.
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Flooded residential area with a red-roofed house partially submerged, water reaching the windows. Debris floats nearby, and a leafless tree stands in the foreground. Other buildings in the background are also affected

Nearly 50 million people, 70 industrial estates, 196 ports, and some of Indonesia’s busiest logistics hubs: Java’s northern coastline is home to this, and more. It is responsible for over 20% of Indonesia’s GDP – and is arguably a cornerstone of Indonesia’s economic future. Yet, it’s also in a precarious position, as it’s acutely exposed to land subsidence, tidal flooding and sea level rise.

To protect North Java’s coastline, Indonesia’s president, Prabowo Subianto, established the North Coast Sea Wall Authority: a dedicated agency overseeing the ambitious Giant Sea Wall project. Estimated to span between 500 to 946 kilometres, this multi-billion-dollar initiative aims to safeguard communities and infrastructure, and secure the backbone of Indonesia’s economy.

While the Giant Sea Wall is a step toward in safeguarding North Java's coastline, global case studies show that continuous giant sea walls often come with substantial impacts on communities, ecosystems, and infrastructure – and high financial cost. To ensure resilience and cost-effectiveness,  the report recommends complementing the sea wall with a tailored mix of strategies—such as hybrid infrastructure and nature-based solutions—adapted to local conditions along the coastline.

To supplement the impact of the Giant Sea Wall project – and suggest complementary ways forward – Haskoning, Deloitte, Witteveen+Bos, and Foresight Works have developed a new report.

Titled “Building Coastal Resilience to Safeguard Indonesia’s Economic Backbone: A Tailored Approach for Giant Sea Wall Implementation,” the report brings together global expertise in infrastructure strategy, coastal engineering and nature-based solutions for complex program delivery.

It offers a roadmap to help the Government of Indonesia form a strategic vision for integrated coastal development, informed by international benchmarks and lessons from large-scale infrastructure projects. This will help secure North Java’s future – and offer a template for other nations that need comprehensive, tailored approaches to coastal protection.

A realistic strategy supported by a tailored approach

For many, coastal protection means sea dikes or sea walls. While sea walls are a proven coastal protection solution, they’re just one approach in a diverse coastal protection toolkit.

Given the stakes involved and the mix of high-value assets and natural coastline across North Java, the report suggests an approach that blends different concepts across three strategic pathways:

  • Go forward strategies designed to expand land and infrastructure through reclamation and offshore structures.
  • Defend strategies that use grey and hybrid infrastructure to reinforce existing coastlines.
  • Restructure strategies which shift at-risk assets and communities inland while restoring coastal ecosystems

With so many potential approaches available, it’s crucial that suggestions are strategically viable – especially given the different people, properties, and assets throughout the region. 

To achieve this, the report focuses on a programmatic “act and plan” approach involving pilot plans in high-risk areas, then looking for ways to implement at a larger scale later.

Rethinking institutional and financial approaches

The report also looks at funding mechanisms and stakeholder engagement. After all, even with the very best engineering strategies and approaches, no project succeeds without financing and institutional support.

It addresses both, urging a dedicated agency to co-ordinate efforts and suggesting novel financing approaches, such as:

  • Bundling revenue-generating assets, like toll roads and hydropower infrastructure, with the sea wall to improve bankability.
  • Applying Land Value Capture mechanisms, including betterment levies, joint development schemes, and special zoning incentives.
  • Exploring Public-Private Partnerships and rights to build to enable cost recovery without compromising public ownership.

Blending new strategies with forward-thinking engineering

The report goes beyond just strategic guidance, emphasising how to integrate green infrastructure (like mangroves and wetlands) with engineered sea walls to enhance resilience and reduce lifecycle costs. This includes suggesting different green, grey, and hybrid solutions, and exploring where each approach would be most effective.

It also explores the potential trade-offs and financial ramifications of different sea wall typologies. From offshore sea walls to nearshore and onshore alternatives, it looks at the construction complexity, environmental impacts, long-term viability, and benefits of each type of sea wall.

Crucially, it offers examples of projects from the Netherlands, South Korea, and Japan that delivered similarly adaptive, multi-functional coastal protection.

A strategic shift for North Java – and beyond

This isn’t just about building coastal protections, it aims to shift the mindset of policy makers by: 

  • Highlighting the limitations of traditional, grey, monolithic infrastructure
  • Encouraging the government to match appropriate protection strategies to local geomorphology and subsidence rates
  • Advocating for stakeholder engagement and buy-in, particularly from fishing communities and local governments

It’s a timely set of recommendations, as the situation in Java is urgent. Without decisive action, Indonesia faces projected damages of USD 1.86 trillion from permanent inundation and coastal disruption. 

At the same time, global experience shows that giant sea walls are not a silver bullet. Successful projects combine structural measures with ecological restoration, stakeholder buy-in, and innovative financing.

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Report

Building Coastal Resilience to Safeguard Indonesia's Economic Backbone

The time to act is now, so we hope these recommendations will help inspire a brighter, more resilient future for North Java – and even prompt more diverse, impactful coastal protection strategies in other regions too.

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Two overlapping documents, with the top one being a Deloitte report titled 'Building Coastal Resilience to Safeguard Indonesia's Economic Backbone,' dated August 2025. It includes logos of partner organisations and a sea wall image with digital graphics. The bottom document is a contents page listing sections like Foreword, Introduction, and chapters on coastal resilience and sea wall implementation.
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