Who the Rotweinwanderweg north of the German Ahr valley, you do not immediately realize that the disaster area is nearby. The route takes in thousands of vines that stretch over rolling hills; the green grapes gleam in the sunlight. All you hear are crickets, the crackling of gravel under your shoes and the hum of a highway in the background. Every now and then a shirtless man comes out from among the vines on a hoeing machine, who Guten Tag murmurs and disappears among the grapes again.
But whoever pricks up his ears hears the sound of sirens. If you focus your eyes, you will see that the sky above the valley has a brownish glow. And anyone who comes here more often knows that it is strange that there are no tourists on the path in July. These are symptoms of the flood disaster that took place less than a kilometer away two weeks earlier.
On the night of July 14, the Ahr violently burst its banks and large parts of the valley were flooded. In places like Sinzig, Dernau and Bad Neuenahr-Ahrweiler, cars and entire houses washed through the streets. Other parts of Rhineland-Palatinate and the neighboring state of North Rhine-Westphalia were also flooded. At least 181 people perished, dozens of others are still missing.
The Ahr Valley is known for Because of the large amount of vines and also in other flooded areas in Germany, Belgium and the Netherlands, wine is rebuilt. Is it a coincidence or did grape cultivation contribute to the flooding?
The main cause of the floods is the exceptional amount of precipitation that fell in a short period of time in mid-July, emphasizes the hydrologist Marie-Claire ten Veldhuis associated with TU Delft. In parts of West Germany fell in two days almost 150 liters rain per m2 while normally 80 liters fall there in the whole of July. “With such quantities, every soil will at some point become saturated and more water will run down the slope,” says Ten Veldhuis. This water ended up in rivers like the Ahr, which overflowed.
Nevertheless, according to Ten Veldhuis, the vines do have an influence on the risk of flooding. “For viticulture, you remove all natural vegetation that helps water infiltrate the soil: roots keep the soil structure open, allowing rainwater to penetrate the soil.” This effect is less with organic viticulture, because more plants are placed around the vines. organic wine however, is still an exception.
German geoscientist Jana Eichel of Utrecht University adds that the machines used by winegrowers can further reduce the sponge effect. “Heavy harvesters can compress the soil, leaving less air and thus less room to absorb water.” He emphasizes that the hills on which wine is grown in West Germany are often “very steep and stony.” “That soil can’t absorb that much anyway.”
If the hills around the flooded valleys had been completely covered with trees and other plants, the damage might have been less. “But whether that would have made a 5 percent difference or 20 percent is impossible to say without targeted analysis,” says Ten Veldhuis. In addition, she emphasizes, the damage would have been greater if the hills had been built up with homes. “Urbanization generates by far the most surface runoff.”
At the moment, winegrowers around the Ahr Valley are mainly victims: many of them have suffered major damage from the floods. So is the family Lingen who has been growing wine on the hills north of the Ahr Valley for ten generations.
Although the four hectares of vines bordering the Rotweinwanderweg survived the floods unscathed, the family home and wine cellar in the valley town of Bad Neuenahr-Ahrweiler are in ruins. The damage is unmissable two weeks after the flood: the flooded basement is still light brown from the mud from floor to ceiling. Most of the rubble has been cleared, but there are still puddles of water and broken parts of wine barrels, machines and broken glass. The wine bottles that survived the tidal wave are covered with a thick layer of mud in coffins.
Four hundred years dry
“We cannot yet foresee how much this will cost,” says materfamilias Tanja Lingen (49) as she walks through the cellar in muddy mountain boots. “Hopefully we can still save some machines and sell the wine that’s in the bottles and barrels that aren’t broken.” It is being investigated whether the drink has been affected by the water.
But even if there are windfalls, the damage for the Lingen family and other winegrowers will run into tens or even hundreds of thousands of euros. A factor here is that many are not insured against flood damage. Lingen: “We’ve been dry here for four hundred years, so we never thought that this could happen.” For example, if pressing machines are broken, the harvest cannot be processed. The Lingen family may also have to sell its grapes to competitors.
In addition, many winegrowers are heavily dependent on tourism: a significant part of the income of the Lingen family comes from wine tasting and the rental of holiday homes at the vineyard. “But tourists are not coming for the time being,” says Lingen. “There is no electricity and it will take months before we have gas again. You cannot celebrate a nice holiday here. The vines look nice, but you can’t even go to the cafe to drink a glass of wine.”
A version of this article also appeared in NRC in the morning of August 2, 2021