It's difficult to overstate just how important the Rhine river is for the countries it flows through.
This mighty waterway serves as an economic lifeline in western Europe, connecting industry in Germany, France and Switzerland with the port of Rotterdam in the Netherlands.
Each year, more than 300 million tons of cargo are shipped along its length, from chemicals to coal, grain to car parts. Major companies have riverside plants that rely on these shipments. And when navigation is disrupted by low water levels — as was the case during this year's drier-than-average summer — the costs can be huge.
It's a scenario the German government is keen to avoid.
As part of an action plan to protect shipping, it's boosting the number of vessels adapted to low water. More controversially, it also wants to deepen a section of the Middle Rhine Valley — a proposal that has been welcomed by businesses but viewed with skepticism by environmentalists and some locals.
What is the project about?
The focus is a 50-kilometer (31-mile) section of the World Heritage-listed Middle Rhine — where the river is flanked by craggy cliffs, hilltop castles and wine-producing villages.
The shipping channel in this part of the Rhine is shallower at certain bottlenecks. That means vessels coming from the North Sea, for example, need to carry less cargo during times of low water to be able to pass through safely on the way to Germany's industrial southwest.
"When in doubt, it has to load much less," said Sabine Kramer from the Rhine Waterways and Shipping Administration (WSA) and the area manager for the project.
The government's plan envisages deepening the navigation channel by 20 centimeters (about 8 inches) — from 1.9 meters at low water to 2.1 meters — to bring this potentially tricky stretch in line with areas further upstream and downstream.
It sounds like a small change, says Kai Kempmann, head of the Committee for Infrastructure and Environment at the Central Commission for the Navigation of the Rhine (CCNR). "But for inland navigation, that is a lot. You can transport a lot more with those 20 centimeters."
According to the WSA, each ship would be able to carry at least an extra 200 tons.
Adapting the river this way is a "gain for shipping, because they can load more cargo and there are expected to be fewer ships traveling as a result," said Kramer.
How will the river be deepened?
To raise the Rhine's level, engineers with the federal waterways authority have proposed installing hydraulic structures that run parallel to the bank, as well as groin-like constructions that extend into the river. These would divert flowing water toward the middle of the Rhine and hold back sediment. Shaving jutting rock from parts of the riverbed and dredging in gravelly areas are also part of the plan.
The project is scheduled to be completed by 2030 and has an initial estimated cost of €180 million ($173 million), 40% of which is for ecological measures.
That hasn't convinced the German Federation for the Environment and Nature Conservation (BUND), though. The NGO fears channeling more water to the middle of the river will harm fish and mussels.
"It is a huge intervention," said Sabine Yacoub, BUND chairperson in the western state of Rhineland-Palatinate. "We fear this will significantly change the riverbanks and impact on fish populations because this is where the fish lay their eggs."
Yacoub is also worried that ecologically important shallow areas could dry out permanently as a result of the changes.
Kramer from WSA Rhine said the deepening measures would not be allowed to cause environmental deterioration. "An environmental impact assessment is underway, and fish stocks are also currently being taken into account," she said.
The Rhine is 'our identity'
Philipp Rahn is also wary of the plans. He is the mayor of Bacharach, a town on the Rhine's banks that relies on tourism for over 90% of its budget. He says he fears any new structures in the river will negatively alter the picturesque landscape.
"These groins would have an enormous impact on our coast here," he said. "We have a rowing club. We have a watersports association. We have a public beach ... And all of these would no longer be able to exist."
"The Rhine is part of our identity," he added. "And we would lose parts of the Rhine here, right in front of us."
The project is still in its planning phase, so it is not yet certain which structures will be installed. Kramer says that although they would be visible when water levels are low, they are "less than many people imagine we are building, so it won't have quite as big an impact on the landscape as many fear at the moment."
Retooling fleets to cope
Periods of low water could become more frequent with climate change, threatening to undermine the Rhine's role as a provider of cheap and energy efficient water transport. At the same time, the alpine glaciers that feed the river are disappearing. According to Sabine Yacoub from BUND, that's what makes this project "short-sighted."
"By the time it is implemented, climate change may well have shifted the goalposts to such a degree that different measures are required and even those may not solve the problem."
In her view, "we should focus on adapting the ships to the Rhine and not vice versa."
Low water in August forced companies to lighten their loads, which led to delays in deliveries and soaring freight costs. It's too early to calculate the damage. But the drought in 2018, which halted traffic on the Rhine altogether, caused a loss of almost €5 billion for German industrial output in the second half of that year.
Some companies, such as chemical giant BASF, have already started upgrading their fleets. BASF's complex in Ludwigshafen on the Rhine transports 40% of its raw materials via river transport. It backs deepening the river as part of a range of measures, including better water-level forecasting.
In a statement, the company said it was "increasingly chartering modern ships suitable for low water" and "increasingly relying on alternative modes of transport, in particular rail."
It's not yet clear when construction on the Middle Rhine could begin. The transport minister has called for the process to be sped up — the energy crisis resulting from the war in Ukraine has only made the transport of fossil fuels on the waterway more urgent. But with community needs, environmental concerns and business interests to weigh up, finalizing the project may take some time yet.
Edited by: Sarah Steffen