Deepening the Elbe in Hamburg: the fairway upgrade secures the future of the port

The tidal Elbe is not only an important shipping route, but also an important habitat for plants and animals - protected by the European Habitats Directive. The channel of the Elbe was therefore adapted in such a way that the access conditions to the Port of Hamburg were improved as required, while at the same time negative consequences for the Tidal Elbe habitat were largely avoided.

In principle, the deepening and widening of a fairway leads to an increase in the tidal range, which in turn leads to changes in current velocities - as previous fairway expansions have also shown. This can lead to increased siltation of the shore zones or, for example, increased transport of salty North Sea water upstream, with effects on the tidal Elbe habitat. If such hydrological effects can be minimised, the impact on nature and the environment can also be reduced.

The hydrological effects of the most recent fairway upgrade were significantly minimised: On the one hand, the dredging volumes for the expansion were reduced to what was absolutely necessary, and on the other hand, this dredged material was successfully utilised for underwater structures in order to limit the impact of the expansion on currents and water levels, and thus also on nature and the environment, to an acceptable level. The results of extensive forecasts carried out as part of the environmental impact assessment, which analysed the effects of the deepening of the Elbe on the environment, show that this can be achieved.</p

Significant ecological impairments that could lead to overarching impairments of the estuary are therefore not to be expected. Whether this remains the case is checked again and again with continuous monitoring.

However, not all impacts could be avoided through careful planning. In this context, ecological impairments caused by the local utilisation of areas for the fairway widening and corresponding accompanying structures should be mentioned in particular. However, they will be fully compensated for by extensive compensatory measures.</p

Most of the current debate surrounding the deepening of the Elbe and possible ecological damage is less about the expansion and more about maintaining the water depths - the effort required for this has increased in view of the increased sediment volumes. Critics argue that the increase in sedimentation is primarily due to the fairway upgrade, which is why it has failed ecologically. They are calling for it to be dismantled in order to reduce maintenance dredging in the Port of Hamburg.</p

<p>In order to reduce the dredging volumes, however, it is necessary to limit the ecologically and economically detrimental recirculation dredging, regardless of the Elbe's fairway depth. The HPA therefore intends to place more dredged material in the Elbe estuary and the German Bight in future. This approach is criticised by some members of the public, who fear environmental damage. However, the fact is that the HPA has examined all environmental impacts in extensive expert reports and is strictly adhering to the strict legal requirements in order to fulfil its legal and social mandate. We are convinced that this strategy of securing the Port of Hamburg's competitive position by improving access for Germany not only makes economic sense, but also ecological sense.</p

We have also been observing a significant increase in sediment levels in the Port of Hamburg for around ten years, even before the fairway upgrade.

<p>This long period of time alone shows that the fairway expansion cannot be the decisive cause of the current development. Rather, the main reason for the increasing sediment volumes is the persistently low water inflow from the Upper and Middle Elbe due to drought and water withdrawals. This has significantly increased the transport power of the tidal current - it washes more sediment from the Lower Elbe into the harbour than before.

The discussed dismantling of the fairway upgrades would not fundamentally change this situation. Instead, maintenance dredging supports the natural transport of sediment into the sea, which the Elbe is currently no longer able to do itself due to the reduced water inflow. Only the use of relocation sites in the Elbe estuary and the German Bight makes it possible to transport large quantities of sediment from the Elbe into the North Sea - they are therefore currently the only feasible solution to reduce the dredging effort again.

Looking at the trend from 2020 to 2022, it can be seen that large container ships leaving the Port of Hamburg had draughts that were 0.8 m higher on average. The average draughts of inbound large container ships even increased by 1.1 m in the same period. This shows that the optimised draught depth of the Elbe is actually being used by shipping.</p

<p>However, in November 2022, the WSV had to temporarily reduce the draught improvements gained through the fairway expansion by around 50%: Strong sediment movements and unexpected munitions discoveries in its area of responsibility had ensured that the target water depths could not be reliably provided. The reason for this development was the morphological aftermath - an effect that often occurs after the completion of deepening measures, when increased sediment volumes and flushing occur in the short term due to subsequent slippage on the newly created embankments. This effect was exacerbated by severe storm surges in the winter of 2022/23.</p

<p>In the meantime, the situation has calmed down and the WSV - partly with the active support of the HPA - is in the process of removing the additional sediment volumes as required and checking and removing suspected explosive ordnance.

<p>The fairway upgrade in Hamburg and the Tidal Elbe enables the efficient and ecologically comparatively low-impact transport of goods, the securing of many jobs and the reliable supply of our region and beyond.

Find out more about the fairway upgrade in a film.