Europe's shrinking rivers are disrupting industry, reducing power generation and intensifying the debate over how to respond to worsening drought. As water levels fall across the continent, authorities and businesses alike are looking for ways to keep freight moving and critical infrastructure operating. Hydrologists warn, however, that digging rivers deeper cannot create more water and could make shortages worse.
Record-low levels on the River Rhine are already affecting German industry. Chemical producers, utilities, steelmakers and agricultural traders have reported transport bottlenecks and rising costs, as barges are forced to carry smaller loads or stop operating altogether on some stretches of the river.
Chemical giant Covestro has warned customers it can no longer guarantee some deliveries because low water is disrupting shipments of raw materials normally transported by river.
Drought is also hitting Europe's energy sector. Romania on Thursday began shutting down the last operating reactor at its Cernavoda nuclear power plant after water levels on the Danube, the river linking central and eastern Europe to the Black Sea, fell to a record low, leaving too little water for cooling.
The plant's two reactors provide around 20 percent of Romania's electricity.
Hungary has faced similar problems, with output at the Paks nuclear power plant, also cooled using water from the Danube, falling sharply. Authorities have announced emergency works near the plant – including a riverbed sill built with around 145,000 cubic metres of rock to raise water levels at its cooling intake.
Vital waterways
The Rhine is one of Europe's most important commercial waterways, carrying fuel, chemicals, grain and other goods through Germany's industrial heartland.
Growing disruption has renewed calls to speed up a long-delayed project to deepen the navigational channel along part of the Middle Rhine.
The scheme, written into German law in 2016, is intended to improve shipping through a section of the river between the western cities of Mainz and St Goar. The stretch includes a bottleneck near Kaub, where low water frequently restricts freight traffic.
Industry groups argue that repeated droughts are making the work increasingly necessary. Supporters see deeper channels as a way of protecting trade and supply chains as low water levels become more frequent.
But hydrologist Thibault Datry, research director at the French National Research Institute for Agriculture, Food and Environment (Inrae), has a different view.
He argues that such projects address the symptoms rather than the cause of the problem.
"You don't create water by digging out rivers," Datry told RFI.
River water is directly connected to groundwater beneath it. Lowering a riverbed can therefore pull groundwater levels down too, reducing water available for homes, industry and agriculture.
"If groundwater levels fall, you reduce water in drinking water catchments, water available for industry and water in meadows or agricultural fields," he said. "There will be a cascade of negative effects on many other uses."
Even a deeper river could eventually suffer from the same shortage. "At some point there won't be enough water left, even for the river that has been dug out. That is what we call maladaptation."
Riverbeds also contain sediment that provides a habitat for fish, insects and other aquatic life. "When you remove sediment from the bottom of a river, you remove the habitat of all the river's inhabitants," Datry explained.
Nature's reservoirs
Keeping more water in landscapes offers a more sustainable response, Datry argues.
For centuries, European societies built infrastructure designed to move water away as quickly as possible. As drought becomes more frequent, the challenge is increasingly the reverse: allowing rain to soak into soils and remain in wetlands and floodplains for longer.
"Nature stores water in wetlands, which are nothing more than enormous sponges," Datry said. "It's the best way of storing and slowing water."
Wetlands can also reduce flood risk. Restoring floodplains and reconnecting former river bends to main channels can help landscapes retain water, although many wetlands across Europe are now degraded.
Reducing evaporation is another priority during increasingly frequent heatwaves.
"Planting trees, creating shade, maintaining forests along waterways or restoring them are all part of the solution," Datry said.
These measures are known as nature-based solutions – instead of relying solely on engineering projects, they seek to restore natural processes that make ecosystems more resilient.
"They are not technical solutions where you build a wall, a canal or dig. They are solutions where we look at functions provided by nature that can make ecosystems more resilient."
The effectiveness of such approaches was assessed in the sixth report of the United Nations Intergovernmental Panel on Climate Change.
Sharing a shrinking resource
Managing a dwindling supply of water may prove to be the biggest challenge of all.
Less water is reaching some river basins, while rain is arriving in different patterns, Datry said. The result is growing competition for water supply between households, agriculture, industry, transport and energy production.
"There is no other solution than to bring all users around a table, present them with scientific facts and decide together what we want," Datry said.
"It isn't logical for one use of water to take precedence over all others, and it wouldn't be socially accepted. We have to share a limited and very precious resource in a sustainable, fair and lasting way."
This article has been partially adapted from this story in French by Stefanie Schüler.
