Danube and Rhine drop to record lows: nuclear plants halted, cruises cancelled, and barges run at a fifth of capacity

A drought that has become annual

The Danube and Rhine are in crisis after a summer of heatwaves and scarce Alpine meltwater. Temperatures in Central Europe pushed past 40°C, and the Danube's flow at Baziaș, where it enters Romania, dropped to 1,700 cubic metres per second, against a July average of 4,700 m³/s. Forecasts warn it could fall below 1,350 m³/s, which would mark the lowest level in 40 years. The Rhine recorded a new low at Cologne (67 cm, two centimetres below the 2018 record) and at Kaub, where the gauge fell to 21 cm early on Tuesday and had recovered only to 23 cm by Wednesday morning, below the 25 cm record of 22 October 2018 and far under the 40 cm mark beneath which meaningful inland navigation is no longer possible. Ferries and grain barges have been suspended in Romania, and freight rail has been halted six hours a day in Hungary.

The scale arrives earlier each year. In July the Danube touched a level it did not reach until October during the 2018 drought. A study led by Dr Sehrish Usman at the University of Mannheim, working with European Central Bank economists, found that last summer's heatwaves, droughts and floods hit a quarter of all EU regions, causing short-term losses of at least €43 bn, with the total expected to reach €126 bn by 2029. On the Rhine, the Kiel Institute has shown that a single month of low water cuts German industrial production by about 1%.

Nuclear plants on the edge

Romania declared a nationwide state of alert for the month of August and sent the army to conduct controlled detonations in the Danube bed, attempting to divert water toward the Cernavodă nuclear plant, which supplies 20% of the country's electricity. Interim defence minister Radu Miruță said the level at the plant rose by two centimetres from the previous day, against a forecast two-centimetre fall, which he counted as a net gain of at least four centimetres and two more days of operation. One of Cernavodă's two reactors had already been shut down at the end of July; authorities have asked citizens and businesses to reduce consumption and to limit public lighting and EV charging.

In Hungary, only one of the four reactors at the Paks nuclear plant is running, producing 240 megawatts instead of the usual 2,000 MW. Prime minister Péter Magyar said the plant had been "within millimetres of having to disconnect completely" and urged Hungarians to cut electricity use between 17:00 and 22:00, warning that mandatory measures will follow without improvement.

Simon Gerards Iglesias of the German Economic Institute (IW) noted that Germany is indirectly exposed. "We are part of an interconnected European energy system. And it is not only nuclear plants that need large amounts of water, but also coal," he said. In Romania, Dacia has halted production at Mioveni until 25 August and Ford Otosan at Craiova until 19 August. Both are the plants' annual summer maintenance stops, scheduled at the start of the year rather than ordered by the energy crisis, though they take about 45 MW off the grid.

A river cruise turns into a bus marathon

At least 120 Spanish passengers on a TUI Danube cruise aboard the MS River Sapphire have seen their week-long holiday become a road trip. The itinerary was to cover eight cities in four countries, starting from Passau, Germany. On the first day the ship could not reach Bratislava and passengers were bussed to Vienna instead. Javier Álvarez, one of the passengers, said the company did not warn them of the low water in time.

What was going to be a gentle cruise has turned into a marathon of kilometres.

Álvarez said they will end up covering up to 1,500 km by bus, with no opportunity to reschedule and no offer of a refund on the roughly €3,000 trip. Fellow passenger Josep Llauina described the disappointment of waiting months for a dream holiday only to be "deceived by the company", walking through heatwaves that were supposed to be balanced by the peace of the river.

On Uniworld's SS Emilie, Cruise Critic executive editor Chris Gray Faust experienced similar disruptions when the ship could not proceed beyond Vilshofen. Three German stops were cancelled and replaced by bus excursions from Vilshofen. Passengers who needed to fly from Nuremberg disembarked a day early and were given a hotel and €50 for dinner. Most passengers reacted positively, she said, though an earlier Belgrade-to-Vienna itinerary had more extensive bus time and much less goodwill.

A waterway on emergency rations

On the Rhine, the shipping bottleneck is strangling industrial supply chains. Barges are loading at a fifth of normal capacity. "The Rhine is Germany's most important waterway. Eighty percent of river transport runs through it," said Gerards Iglesias. The chemical and steel sectors are already seeing bottlenecks. In 2018, Germany's weather service called that summer a Jahrhundertsommer (a once-in-a-century summer) after the Rhine spent 132 days at low water. Then-federal transport minister Andreas Scheuer said those events could not be allowed to repeat. They repeated in 2022, 2025, and now 2026.

Ghost fleet from the past

Near Prahovo, Serbia, the receding Danube has exposed dozens of Nazi warships scuttled in 1944 while the Kriegsmarine fled the Red Army. Around 200 vessels, minesweepers, patrol boats and barges, were sunk to block the river. The rusted hulls still carry unexploded ordnance, making removal slow. An EU-backed project under the Western Balkans Investment Framework, paid for by a €16 million European Investment Bank grant awarded in July 2024, aims to refloat 21 of the most obstructive wrecks. The first were lifted in 2024 and the EIB says the work will run until 2028. The debris costs Serbian shipping about €5 million a year. Wrecks too large to lift will be buried deeper in the riverbed.

The drought has also revealed mammoth bones in Bulgaria and World War II bombs in Serbia and Hungary. The discoveries are a sideshow to the economic and energy crisis unfolding along Europe's two arterial rivers.