Water levels on the Rhine in Germany have fallen after recent dry weather and cargo vessels cannot sail fully loaded on sections of the river, traders said on Tuesday.
The Rhine is too shallow for normal sailings from Duisburg and Cologne to the important Kaub navigation point south of Koblenz, traders said.
Shallow water means vessel operators impose surcharges on freight rates, increasing costs for cargo owners.
A heatwave with sunshine for the rest of this week is forecast for Germany so no immediate improvement is expected in water levels.
Unusually low water levels on the Rhine caused by the drought and heatwave in summer 2018 caused major supply bottlenecks and production problems for German companies.
The Rhine is an important shipping route for commodities including grains, minerals, chemicals, coal and oil products including heating oil.