- A severe lack of rainfall and a sequence of heatwaves from May onward has taken a visible toll on the region's waterways.
- In France, parched conditions mean it has become possible to cross the Loire River on foot in some places.
- Meanwhile, the drought-stricken waters of Italy's Po River have revealed artifacts dating back to World War II — including a 50-meter-long barge and a previously submerged bomb.
Europe's rivers are running dry after an extended period of extremely hot weather, ratcheting up fears over food and energy production at a time when prices are already skyrocketing due to Russia's invasion of Ukraine.
A severe lack of rainfall and a sequence of heatwaves from May onward has taken a visible toll on the region's waterways.
In France, it has become possible to cross the Loire River on foot in some places; it is feared that water levels at a key German chokepoint on the Rhine River, one of Europe's key waterways, could once again close to commercial traffic; and the drought-stricken waters of Italy's Po River have revealed artifacts dating back to World War II — including a 50-meter-long barge and a previously submerged bomb.
"We haven't seen this level of drought in a very long time. The water levels in some of the major waterways are lower than they have been in decades," Matthew Oxenford, senior analyst of Europe and climate policy at The Economist Intelligence Unit, a research and advisory firm, told CNBC via telephone.
"For some of the main channels, there's very little leeway, sometimes less than 30 centimeters of leeway before the channel is completely inoperable for any sort of shipping," he added.
"So, that's going to have very significant impacts on the economic and human activity that's taking place around these waterways seeing as we're likely to remain in some form of drought for some time to come."
Europe is in the grip of what is likely to be the region's worst drought in at least 500 years, according to a preliminary analysis from the European Union's Joint Research Center.
As of early August, the Global Drought Observatory report said that roughly two-thirds of Europe was under some sort of drought warning, meaning the soil has dried up and vegetation "shows signs of stress."
The analysis found that nearly all of Europe's rivers have dried up to some extent, while water and heat stress "substantially reduced" the summer crops' yields. Forecasts for grain maize, soybean and sunflowers were expected to be 16%, 15% and 12% below the average of the previous five years, respectively.
That comes as food prices remain stubbornly high amid Russia's onslaught in Ukraine, a major producer of commodities such as wheat, corn and sunflower oil.
The EU's report warned that the Western Europe-Mediterranean region would likely see warmer and drier than usual conditions persist through to November.
To be sure, the deepening climate emergency has made high temperatures and droughts more intense and widespread. And lower nighttime temperatures that typically provide critical relief from the hot days are disappearing as the planet warms.
"The problem is the severity of this particular drought," Axel Bronstert, professor of hydrology and climatology at the University of Potsdam in Germany, told CNBC via telephone.
"If you grow up in central Europe, people usually like the sun — but now we hope for rain," Bronstert said, noting that it had previously been unheard of for some smaller rivers in the region to completely dry up at this time of year.
"Without really strong rainfall in the next few weeks, the probability that the water levels will further decline is high," he added.
Alongside the ecological and health impacts of the drought, Bronstert said parched conditions had resulted in a "very bad" harvest for many different crops in Germany.
Surging food and energy prices have fueled a sharp upswing in inflation, with consumer prices in the 19 countries using the euro rising to a new record high of 9.1% in August.
"I think the larger point that I want to stress is that anomalies like this are in a sense going to become more common over the coming years because of climate change," the EIU's Oxenford said, citing the possibility for more intense droughts, storms, heat waves and floods in Europe.
"So, I think the takeaway for dealing with the economic impact of all of this is that countries are going to need to invest more in preparedness for things that used to be very uncommon — but that are now going to become much more common occurrences as climate change upends a lot of patterns of activity that have been built in over centuries."
Oxenford said the economic impact of Europe's evaporating waterways was likely to be "multi-faceted," highlighting the prospect of a halt to shipping along the Rhine River as one of the major risks.
Snaking roughly 820 miles (1,320 kilometers), the Rhine River is one of the longest and most important rivers in Europe. It connects the major port of Rotterdam in the Netherlands through the industrial heartland of Germany and further south into landlocked Switzerland.
Water levels of Germany's Rhine River have stabilized above crisis levels in recent weeks. However, forecasts of an extended period of high temperatures and scant rainfall have exacerbated fears that the transport of everything from food to chemicals to energy could soon grind to a halt.
Water levels at Kaub — a measuring station west of Frankfurt and a key chokepoint for water-borne freight — are forecast to drop to 86 centimeters (around 34 inches) by the end of the week, according to German government data. A normal water level would be around the 200-centimeter mark.
In 2018, water levels of the Rhine dropped to just 30 centimeters in places, forcing ships to temporarily stop hauling cargo.
Andrew Kenningham, chief Europe economist at consultancy Capital Economics, said in a research note that if the fall in the Rhine's water levels persists, it could subtract 0.2 percentage points from Germany's gross domestic product in the third and fourth quarters of this year.
Kenningham said the fall in the Rhine's water level was a relatively minor issue for German industry when compared to the region's deepening gas crisis, however.
Elsewhere, the warming temperatures of France's rivers have in recent weeks threatened to reduce the country's already low nuclear output. Summer heatwaves have further warmed rivers such as the Rhone and Garonne that state-owned energy supplier EDF uses to cool its nuclear power plant reactors.
The French nuclear power regulator has since extended temporary waivers to allow five power stations to continue discharging hot water into rivers ahead of a looming energy crisis, Reuters reported.
And, in Norway, a northern European country that relies heavily on hydroelectric power, the lack of rain has meant the amount of electricity generated by dams has dropped precipitously. As a result, the Norwegian government announced in early August that it plans to limit power exports.
European governments are scrambling to fill underground storage facilities with gas supplies in order to have enough fuel to keep homes warm during the coming months.
Russia — which supplied roughly 40% of the EU's gas last year — has drastically reduced flows to Europe in recent weeks, citing faulty and delayed equipment.
— CNBC's Emma Newburger contributed to this report.