Denmark expands coastline with 300,000 sqm land reclamation
Baltic Sea tunnel project creates artificial island with ecological focus
1World's longest immersed tunnel
The Fehmarnbelt Tunnel will stretch 18km between Denmark and Germany, becoming the longest road-and-rail tunnel of its type. Comprising 89 massive concrete elements (217m long, 73,000 tonnes each), it will be submerged in a seabed trench. This engineering feat aims to reduce Hamburg-Copenhagen travel time to 2 hours by train and just over 1 hour by road, significantly cutting reliance on air travel. The project represents a major infrastructure upgrade for Scandinavia-Europe connections.
2Ecological land reclamation
Excavated seabed material from tunnel construction has been repurposed to create a 300,000 sqm artificial island off Rødbyhavn. Designed as a nature spot, it features walking trails, three ponds, and habitats for birds, amphibians and insects. The site uses soil containing native plant seeds from tunnel construction, carefully selected to withstand harsh coastal conditions. Project managers emphasize creating "distinctive coastal nature" where visitors can observe ecosystem development from inception.
3Dual-purpose infrastructure
The project combines transport improvement with environmental enhancement. While the tunnel addresses mobility needs between Denmark and Germany, the artificial island provides recreational space and biodiversity habitat. State-owned Sund Bælt highlights the area's unique salt marshes and diverse wildlife as key visitor attractions. This dual approach reflects contemporary infrastructure priorities balancing development with ecological considerations.
4Construction timeline
First agreed in 2008, the Fehmarnbelt project faced delays from ferry operators and conservation groups before construction began. The tunnel is scheduled for 2029 completion, with the artificial island being developed concurrently. The extended timeline demonstrates the complexity of multinational infrastructure projects requiring environmental approvals and stakeholder alignment across borders.
5Material reuse strategy
The project exemplifies circular construction practices by repurposing all excavated seabed material. Rather than treating this as waste, engineers designed the artificial island specifically to utilize these resources. This approach minimizes environmental impact while creating value-added assets. The method could inform future coastal projects seeking sustainable solutions for large-scale earthworks.
6Comparative projects
Denmark is concurrently developing Lynetteholm, another artificial island near Copenhagen to house 35,000 people and combat rising sea levels. Additionally, the Holmene project will create nine sustainable tech hub islands. These initiatives demonstrate Denmark's strategic use of land reclamation for multiple objectives - from climate adaptation to urban expansion and economic development.
7Visitor experience design
The artificial island's landscaping prioritizes immersive nature experiences. Visitors can observe ecological succession from bare land to established habitats. Design elements include carefully placed walking trails that provide access while minimizing disturbance. This "nature from scratch" concept offers unique educational opportunities about coastal ecosystem development rarely visible to the public.
8Transport transformation
The Fehmarnbelt Tunnel will fundamentally alter regional connectivity, creating the first fixed link between Scandinavia and continental Europe. By shifting Hamburg-Copenhagen trips from ferry/air to rail/road, it reduces carbon emissions while improving reliability. The project exemplifies how major infrastructure can reshape economic geography and travel patterns across Northern Europe.