Low water on the Rhine and Danube is once again disrupting European freight. But companies are no longer treating drought as an exceptional event. From shallow-draught vessels to better forecasting and multimodal contingency plans, a new model of climate-resilient logistics is beginning to emerge.
Europe’s supply chains have a capacity problem. It just happens to look like a weather problem.
After weeks of heat and scant rainfall, water levels on the Rhine and Danube have fallen to exceptionally low levels this summer. Barges are still moving on much of the network. Yet some are carrying only a fraction of their normal loads. On the Rhine, vessels have recently been sailing at around 20% of capacity in particularly constrained stretches. The effect is being felt by steelmakers, chemical producers, fuel distributors and the Port of Rotterdam, while low water on the Danube is disrupting grain and oil shipments further east.
The problem is not that Europe’s rivers suddenly cease to function. It is that their effective freight capacity contracts dramatically.
That distinction is important. A barge capable of carrying several thousand tonnes may still make its journey, but with perhaps half, a third or even a fifth of its normal cargo. Moving the same volume then requires several vessels. Freight rates rise. Available barges become scarce. Low-water surcharges kick in. Shippers scramble for rail and truck capacity at precisely the same moment as their competitors.
Europe’s inland waterways are, in other words, becoming variable-capacity infrastructure. And supply chains built around them are having to adapt.
The wake-up call came in 2018
For German industry, the turning point was the Rhine drought of 2018. Water levels around Kaub — a narrow section of the Middle Rhine that acts as a key shipping bottleneck — fell so far that freight movements were severely curtailed.
The consequences spread far beyond shipping companies. Chemical plants struggled to secure raw materials, fuel distribution became more expensive and German industrial output suffered. The lesson was uncomfortable: a river that had been regarded almost like a railway or motorway was subject to a form of capacity risk that companies had barely incorporated into their planning.
Germany subsequently developed an eight-point low-water action plan covering better forecasts, improved information about navigable depth, infrastructure measures and support for vessels capable of operating in shallower water.
Companies made their own investments.
BASF, whose Ludwigshafen complex depends heavily on Rhine transport, commissioned a new generation of low-water tanker. The Stolt Ludwigshafen, introduced in 2023, can transport around 800 tonnes through the critical Kaub section even at a gauge reading of just 30 centimetres. At moderately low water it can carry roughly twice as much as a conventional inland vessel.
This represents a fundamental change in supply-chain thinking. Rather than designing logistics around normal conditions and improvising during droughts, companies are beginning to design logistics around the disruption itself.
Why trucks cannot simply take over
The obvious answer to unreliable river transport is diversification. When a barge cannot carry the goods, put them on trains or trucks.
In practice, the arithmetic is unforgiving. Inland vessels dominate the movement of bulk commodities precisely because they move huge volumes efficiently. A large barge carrying chemicals, grain, fuel or minerals can replace dozens of trucks. At a system level, transferring a significant share of Rhine freight onto roads would require thousands of additional vehicle movements.
Reuters reported this summer that replacing Rhine distribution of refined fuels in the event of a closure could require around 3,000 additional road tankers a day in Germany alone.
Rail faces a similar constraint. It is an essential alternative for selected flows, but spare freight capacity does not suddenly materialise when river levels fall.
The result is a more nuanced resilience strategy. Instead of abandoning waterways, sophisticated shippers are building layers of redundancy around them: shallow-draught vessels for critical cargo, larger inventories at strategic locations, advance agreements for rail capacity and road transport reserved for higher-value or urgent shipments.
This is not cheap. Resilience rarely is. Inventory ties up working capital. Specialised vessels cost money. Reserved rail capacity may go unused during wet years.
But an idle steelworks or chemical plant is considerably more expensive.
From deeper rivers to smarter rivers
Governments face a harder version of the same decision.
Traditional river engineering can remove bottlenecks, improve fairways and increase the usable draught of vessels. Germany is pursuing improvements to the Middle Rhine, where sections offer less navigable depth than the stretches upstream and downstream.
But dredging and deepening have limits. They can improve navigation where sediment or local river morphology creates a bottleneck. They cannot conjure water during a continent-wide drought.
The Danube is therefore becoming a laboratory for a more flexible approach.
Under the EU-backed FAIRway Danube II programme, authorities are testing temporary “flexible infrastructure” in Austria, Croatia, Romania and Bulgaria. One technique involves positioning loaded barges in shallow sections to narrow part of the river temporarily. This concentrates the current in the navigation channel, increasing velocity and helping maintain fairway depth. Once the low-water period passes, the structures can be removed.
It is an intriguing concept: infrastructure that changes with the river rather than attempting to force the river permanently into one configuration.
Perhaps even more consequential is an investment that involves no concrete at all.
FAIRway Danube II is extending operational water-level forecasts to six days in Austria and Hungary and seven days in Romania and Bulgaria. Authorities are also studying whether useful forecasts could eventually stretch as far as six weeks.
For logistics managers, six weeks of warning would be transformative.
A company could accelerate inbound shipments, build inventory, reduce barge loads, reserve trains or adjust production before the river reaches a critical threshold. What today looks like an emergency response could become a routine planning decision.
Hydrology would effectively become another input into the supply-chain control tower, alongside freight rates, port congestion and demand forecasts.
A new definition of infrastructure capacity
There is a strategic contradiction at the heart of European transport policy.
Europe wants to move more freight onto waterways because barges are efficient, reduce road congestion and can produce far fewer emissions per tonne transported. At the same time, climate change is making waterway capacity less predictable.
The answer is not to abandon inland shipping. For many bulk supply chains there is no realistic replacement at comparable scale and cost.
Instead, planners may need to rethink what “capacity” means.
A river theoretically capable of handling 100 units of freight but repeatedly reduced to 30 or 40 during dry summers is not truly a 100-unit transport corridor. Its economically relevant capacity has to incorporate hydrological risk.
That has implications far beyond shipping. This summer, Europe’s low rivers have simultaneously disrupted freight movements, constrained hydropower generation, complicated nuclear-plant cooling and threatened agricultural production. The same missing water is being demanded by logistics operators, power companies, farmers, households and ecosystems.
Water scarcity is therefore becoming a supply-chain issue, an energy issue and an industrial-policy issue at the same time.
The progression is telling. In 2018, exceptionally low water looked like a crisis. In 2022 it looked like a recurring risk. By 2026, it is starting to look like something European supply chains simply have to be designed around.
The winning strategy will not be a single deeper channel, a larger fleet of trucks or one new class of barge.
It will be a combination of better vessels, better forecasts, smarter infrastructure, larger buffers and genuine multimodal redundancy.
Europe’s rivers are unlikely to disappear from its supply chains. But the era in which businesses could take their carrying capacity for granted is already ending.
