Europe's industrial heartland is facing mounting production cuts and supply disruptions as record-low water levels on the Rhine and Danube rivers choke off cargo transport and force nuclear plants offline. The Rhine's key measuring point at Kaub dropped to 27 centimetres in late July, below the critical 30-centimetre threshold, while the Danube hit a record low of 23 centimetres in Budapest on Thursday—10 centimetres below the previous 2018 record.
Most inland vessels can't pass the Kaub bottleneck, commodity-market intelligence provider Argus reported Wednesday. "In practice, the Upper Rhine and the Main rivers are now effectively cut off from the Amsterdam-Rotterdam-Antwerp (ARA) trade hub," Argus said. Cargo volumes have been heavily restricted for the few vessels still able to make the journey, driving freight rates to record levels. The Rhine flows for about 1,230 kilometres from the Swiss Alps through or along Switzerland, Liechtenstein, Austria, Germany, France and the Netherlands before reaching the North Sea.
Industrial Output Under Pressure
Low water levels have restricted deliveries of naphtha and liquefied petroleum gas from North Sea ports to inland factories. ICIS reported that LyondellBasell declared force majeure on butadiene supplies from its Wesseling plant after low water levels disrupted feedstock deliveries. BASF flagged possible force majeures or product shortages as it relies on the river for transport.
Thyssenkrupp has slightly reduced blast furnace production at its Duisburg plant because barges carrying raw materials have struggled to navigate shallow chokepoints such as Kaub. The company suspended its own barge operations and chartered shallower-draught vessels, though it said customer deliveries weren't at risk.
Rising water temperatures have made industrial cooling systems less efficient, adding pressure on nuclear and thermal power plants. The oil and energy industries have faced steep low-water surcharges and rising freight rates for shipping diesel and petroleum products upriver, while coal-fired power stations have struggled to secure fuel supplies as barge loads drop.
Nuclear Plants Go Offline
Hungary's Paks Nuclear Power Plant has reduced output and shut down one of its four reactors, according to operator MVM. Hungarian media reported it was the first-ever shutdown of a complete block at the nuclear plant. Combined with earlier reductions, the shutdown brought the plant's output down to about 60% of capacity.
Romania's state-owned nuclear power producer, Nuclearelectrica, shut down Unit 1 at the Cernavodă power plant on Tuesday because of what it described as the "very low, unprecedented" level of the Danube. Romania's energy ministry said Unit 2 would be disconnected early Thursday, leaving both reactors offline simultaneously because of low water levels for the first time.
The shutdowns are increasing pressure on regional electricity supplies. Hungary is replacing the lost output with a combination of imports and domestic gas-fired generation, according to Mavir data cited by Hungary's national news agency, MTI. Romania's Energy Ministry said the loss of both reactors would increase its reliance on imports, putting further upward pressure on power prices, Reuters reported.
Danube Disruption Spreads
The Danube, which flows through or borders ten countries including Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, Moldova and Ukraine, has also seen historically low water levels this July. Due to continued high temperatures and a lack of rainfall, Hungary's official water-monitoring service forecast a further decline over the coming days.
The Hungarian Construction and Transport Ministry said in its latest update on Tuesday that most cargo vessels had been halted along the Hungarian section of the Danube, while those still operating were carrying only 10% to 20% of their normal loads. Around 15 hotel ships were also stranded. The Associated Press reported that cargo shipping had stopped in some affected areas, while vessels continued operating with sharply reduced loads elsewhere. In Serbia, barges and tankers were carrying about 30% to 40% of their normal capacity.
Fuel transport in Serbia has been affected too. The country received only 25% of its planned fuel imports in July because low Danube levels restricted barge deliveries, Energy Minister Dubravka Đedović Handanović said. The government subsequently authorised energy companies to draw on operational fuel reserves to safeguard supplies.
Low water levels have also affected agriculture, disrupting grain shipments and irrigation in Serbia, including in the northern agricultural region of Vojvodina. In Romania, the authorities have restricted irrigation as flows on the Danube fell to their lowest level since 1996, while river shipping has also been partially disrupted.
Emergency Measures
Hungary declared an emergency drought alert on Thursday after drought thresholds were exceeded in 66 of the country's 84 water-management districts, Environment Minister László Gajdos said. "This means that experts from the Water Management Authority will carry out drought relief measures at the highest alert level across 74% of the country," he added, according to Hungarian news website Telex.
Why This Matters:
The Rhine and Danube disruptions expose Europe's vulnerability to climate shocks at a moment when the continent can least afford industrial slowdowns. Germany's manufacturing base depends on Rhine cargo flows—when Kaub becomes impassable, supply chains seize up and freight costs spike. The nuclear shutdowns in Hungary and Romania show how climate stress compounds energy security risks, forcing countries back onto gas-fired generation and imports just as Europe tries to reduce its reliance on external suppliers. For member states already grappling with high energy prices and inflation, the loss of baseload nuclear capacity and the surge in transport costs threaten to push electricity prices higher and slow economic recovery. The drought also underscores the need for infrastructure investment in alternative transport routes and water management—decisions that must be made at national level, not dictated by Brussels, because the costs and trade-offs differ sharply between countries.