Redesign Seine-Schelde-Leie

Redesign Seine-Schelde-Leie


The assignment is part of the larger Seine-Scheldt project. This cross-border project aims the connection of the Seine basin in the Paris region with the Scheldt basin in the Antwerp-Rotterdam region by means of an efficient shipping connection. In the future, it should be possible to sail ships up to 4,500 tons (CEMT class-Vb ships) from Paris to Antwerp, and vice versa.

On Flemish territory, the project mainly involves adapting the Leie from a 1,350-tonne waterway to a 4,500-tonne waterway. This requires a deepening of the navigation channel. Locally, bend widening is carried out to enable a ship's length of up to 185m and passes are provided for the largest ship types.

The deepening of the Leie brings with it a lot of adjustments:

  • Rebuilding the weirs at Sint-Baafs-Vijve and Harelbeke;
  • Work on the bridges;
  • Construction of the Moleneiland as a green zone with a fish passage;
  • Redesign the immediate environment so that a coherent whole can be formed.


One of the most radical and spectacular parts of the works in Harelbeke is the replacement of the lock and the weir.


The big challenges were:

  • Guaranteeing navigability during the execution of the works;
  • The requirements regarding hydraulics (including water management) during the entire duration of the works. 

The new lock will be placed on the site of the current lock and will be 230m long, 12.5m wide and 4.7m deep. This new lock will be fitted with intermediate doors. For smaller ships, only one part of the chamber will be used, so that they can be channelled faster and water consumption is limited.

Next to the lock, there will be a double weir with turbines. These turbines generate the necessary electricity for the lock to function in an energy-neutral way.

During implementation, the passage for all ships is guaranteed. To make this possible, a temporary weir is needed to be built on the site of the Moleneiland. 

To allow freighters with three layers of containers to pass, a clearance height of 7 meters was required over a width of 35 meters.

However, the Hoge bridge did not meet these requirements. That is why a new fixed arch bridge was built on the site of the present Hoge bridge, which fits perfectly in the surroundings in terms of scale. This new bridge is wider to allow pedestrians and bikers a safe passage.


The Banmolens bridge will also be developed as part of this project. From now on this bridge will serve as a fixed road bridge which makes the access to the Banmolens possible. Furthermore, the project includes the construction of a new movable bicycle bridge, called the Bloemmolens bridge.

A 'River Restoration' project has been linked to the Leie Scheldt inland navigation project. The river which has been channelled in the past has to be adapted in such a way that the ecological potential of the river is maximized. In concrete terms, this means providing as much as possible nature-friendly bank defences, reconnecting and moving through cut-off 'meanders' and restoring the possibilities for fish migration.  

The work is immediately used to redesign and renew the connecting roads and sewers. Here, specific attention is paid to the road user and the maximum integration of green areas is central.

Seeing as the project is executed as Design&Build, SBE is involved from the beginning to the end of the project:

  • Drawing up required calculation notes for concrete construction, steel construction and geotechnics of both the final and the temporary constructions;
  • Nautical study
  • Drawing up necessary drawings and plans + revisions.

The following services must be performed for the following components:

  • 3 Bridges (2 x fixed and 1x movable);
  • Lock complex (both temporary and new);
  • Weir complex (both temporary and new);
  • Pump station;
  • Shore defence;
  • Roadworks & sewerage;
  • Control building;
  • Fish passage;
  • Quay walls;
  • Various other small works.
Port & river engineering
Civil engineering & infrastructure
2011 - ...