A combination of severe heat and little rain has left many of Europe’s rivers drier than normal this summer, revealing formerly submerged relics and blind spots in the continent’s supply chain.

The two rivers at the center of the crisis are the Danube and the Rhine.

Both serve as major arteries for shipping and freight transport across Europe. In 2025, Germany and the Netherlands accounted for nearly 72% of the EU’s total inland waterway transport, according to the European Statistical Office, or Eurostat.

Beyond freight, they also have long histories dating back to wartime and prehistoric animal migration. This summer, record-low water levels…