Navigability of inland waterways
The navigability of inland waterways can be restricted by both low water and high water. Since restrictions due to floods are usually of shorter duration, they have less economic significance than low-water events. Restrictions due to low water have lasted more than 100 days in individual years, in the case of floods no more than 14 days.
During long dry periods, water levels and flow velocities in the waterways decrease. Even low water can mean that ships can no longer be fully loaded. The reduced river width restricts the possibilities for meeting and overtaking, which in turn leads to low travel speeds. The restrictions on inland navigation can sometimes have a significant impact on individual companies or entire production and supply chains. These can range from increased transport costs to production losses in companies with just-in-time production. Especially for the Rhine and the Danube, there will be increased restrictions on navigability in the future.
During floods, the water levels and flow velocities in the rivers rise. If this endangers traffic safety, buildings near the banks or bridge clearance heights, navigation will be stopped. Since floods do not usually last that long, they have less economic relevance for shipping. The inland and maritime waterways themselves as well as ports and maritime infrastructures can also be damaged by floods.
Indicator from the monitoring on the DAS: Flood closures and low water restrictions on the Rhine