A persistent heatwave has pushed water levels on the Rhine to unusually low marks for mid-summer, forcing cargo vessels to sail at a fraction of capacity and driving up freight costs across Germany's most important inland waterway.
Vessel operators are imposing surcharges as barges navigate shallow stretches south of Duisburg and Cologne, including the critical chokepoint at Kaub, where tankers can carry only about 460 metric tons — far below normal loads. Transport costs on the Rotterdam–Karlsruhe route have risen to as much as €70 a ton, up from €45 in late June. Roberto Spranzi of the German Transport Cooperative for Inland Navigation said levels are the lowest he has seen in 45 years.
The water at Kaub fell to 53 centimetres on Monday and is expected to drop below 50 centimetres in coming days, though rain is forecast from Friday. Environment Minister Carsten Schneider is set to unveil a nationwide low-water information system on Wednesday. The disruption follows a difficult year: inland waterway freight in 2025 totalled 171.6 million tons, the lowest since German reunification.