So what can be done to help river barges stay afloat? In Germany, one proposed solution is to deepen a shallow section of the Rhine.
This would enable cargo riverboats to carry at least an extra 200 tonnes, according to Germany's Waterways and Shipping Office.
But plans to deepen a 31-mile section of the World Heritage-listed Middle Rhine - where the river is lined with castles and vineyards - are controversial. เว็บตรงบาคาร่า
"Deepening and widening the area will have knock-on effects on the environment - flooding and destroying ecosystems," says Ms Schiffling. "And, of course, it doesn't solve the core problem. No matter how deep you make it, there's just not enough water."