Little rain. Much worse heat

LITTLE RAIN. But the bigger problem is not that there is not much of it.

Europe's great rivers are running at their lowest ebb in decades, if not centuries. The Rhine hit a 25cm draft at Kaub, a key chokepoint near Koblenz, matching the record low set in October 2018. In 2018 it took until autumn for that to happen; this year it arrived by late July. Barges sail a fifth full. At Budapest, the Danube fell to 23cm, below the previous all-time low of 33cm. A cruise ship ran aground off Vidin, in Bulgaria, leaving 186 tourists short of food and water. In Italy, the Po has never been so low so early in the year. Seawater is creeping upstream into its delta, salinating the soil of a farming region that produces much of Europe's cheese and rice. More than 100 municipalities in Piedmont and Lombardy are trucking in drinking water.

The obvious question is when the rain will return. The answer is that it might, but it will not help very much. That is the uncomfortable truth about Europe's water crisis: this is no longer a rainfall story. It is an evaporation story.

The drought multiplier

The European summer of 2026 has been exceptionally hot. Between April and June, large parts of the continent from Portugal to southern Finland received below-average rainfall, according to Copernicus, the EU's climate service. But the researchers at the World Weather Attribution group, a consortium of climate scientists, found something disquieting in their analysis: there has been no clear long-term trend towards lower rainfall across much of Europe. What has been rising is temperature. And because evaporative demand increases exponentially with heat, the same amount of rain falls on a much thirstier landscape.

The result is that drought is being driven less by the absence of precipitation and more by the presence of warmth. The Climate Impact Company, a forecasting firm, predicted the current dry spell as far back as April, pointing to a combination of strong El Nino conditions, a North Atlantic warm hole, and marine heatwaves in the Norwegian and Mediterranean seas. The forecast was correct. Its August outlook is similarly dire: high pressure is expected to continue over Central and Eastern Europe, with temperatures pushing above 40C across swathes of the continent.

That matters because the instinctive response to a dry river is to wait for rain. When the problem is heat, rain is not the same cure. Summer storms, as Alessandro Delpiano, secretary-general of Italy's Po River Basin Authority, put it, cannot solve "deep-rooted problems". A short shower on parched ground evaporates before it reaches the roots. A flash flood runs off hard soil instead of replenishing a watershed. The mechanism is straightforward: warm air can hold more moisture, hot soil drinks it up, and what does reach the river is rapidly lost to evaporation again.

The energy and shipping squeeze

The consequence is infrastructure that was designed for a wetter, cooler past. Europe's energy system, in particular, is built around water. The Danube's fall forced Hungary to shut down the Paks nuclear power plant, which supplies nearly half the country's electricity, because there was not enough water for reactor cooling. Serbia cut output at its coal-fired plants for the same reason. Romania, where Danube flow had fallen to 1,630 cubic metres per second-about a third of the July average-shut down reactors at Cernavoda and even carried out a controlled explosion on a riverbank rock in a desperate bid to improve water flow.

The Rhine is a different kind of bottleneck. It is Europe's busiest inland waterway, carrying chemicals, fuel, grain and construction materials between the seaports of Rotterdam and the industrial hinterland of Germany, France and Switzerland. The Kaub gauge sets the maximum draft-and therefore the laden weight-for every barge on the river. When it falls below the equivalent water level threshold of 77cm, barging becomes structurally uneconomic. That line was broken weeks ago. Rotterdam-Karlsruhe tanker freight has climbed to €60-70 per tonne, up from €45 in late June. Each barge that cannot carry its normal load equals 50 to 150 additional truck deliveries. The cargo spill into the road network raises costs, emissions and congestion.

Shipping will not be suspended entirely. Martin Wolters of the Rhine Waterways and Shipping Authority told German broadcaster WDR that vessels will spread cargo among more ships and carry lighter loads. But that is not the same as normal operations. "There comes a time," one commodity trader told Reuters, "when loads are too small to be worthwhile, or vessel owners are worried about damaging their ships."

A structural problem, not a seasonal one

To be sure, this is not the first time Europe's rivers have run low. The drought of 2018 was severe, and 2022 saw a similar event. What is different this time is speed and geography. The Rhine in 2026 reached levels that in 2018 did not bottom out until October. The Danube's 30-year low spread across ten countries simultaneously. And the Po's early collapse means Italy's agricultural heartland is being squeezed before the growing season has even reached its peak.

The deeper problem is that Europe's water infrastructure is locked into a climate that no longer exists. A 2026 study published in Nature examined hydrological drought projections across Europe under climate-change scenarios and found that drought frequency, severity and spatial extent are all increasing, particularly in southern and central regions. Spring is projected to be the most drought-prone season, which matters because spring is when snowmelt should replenish rivers and reservoirs for the summer ahead. That replenishment is failing. Lake Maggiore and Lake Como each lost between 6% and 7% of their water in a single week as stored winter water was diverted to irrigation. The snow reserves that the Po depends on melted too early under record June and July heat.

The EU's own Joint Research Centre has put the average annual cost of drought at €3.3 billion, with between 39% and 60% of those losses falling on agriculture and 22% to 48% on the energy sector. The 2022 drought, which the Copernicus service described as the most extreme in 500 years, was substantially worse.

The wrong lessons, the right ones

The natural temptation is to reach for the obvious solutions: build more reservoirs, invest in desalination, dredge rivers, or impose emergency water restrictions. Some of these are necessary. The twenty northern Italian river basins that have been granted permission to bypass minimum flow requirements are already improvising. But infrastructure is slow, expensive and often politically contentious. Reservoirs that capture runoff in wet years do little when evaporation itself is the problem. Desalinated water is too energy-intensive for most agricultural use. Dredging is a short-term fix for a long-term trend.

The better answer is to treat water the way the climate is actually using it: as a scarcer and less predictable resource. That means pricing it accordingly, investing in drip irrigation and soil-moisture retention that can save large amounts of water, and accepting that some crops will not grow in some places any more. It also means energy systems that are less dependent on river water for cooling, whether through air-cooled alternatives or siting new plants where water is available. The nuclear plants on the Danube were not badly located; the river they depend on has changed.

None of this will happen quickly. The political economy of water is stubborn. Farmers resist restrictions. Municipalities resist rationing. Politicians resist telling voters that their tap water may need to be trucked in. The result is a familiar one: a series of emergency measures that address symptoms rather than causes, followed by a return to business as usual until the next crisis.

The drought of 2026 is not an anomaly. It is a preview. And the lesson from the rivers that are running dry is that Europe can no longer afford to wait for the rain.