It's not often that an SOS arrives by email, but that was what I found in my inbox in early December. A 'death warrant', apparently, had been drafted for the wines of Sauternes and Barsac; a 'terrible menace' was thus hanging over Yquem, Rieussec, Suduiraut and their like. Cripes! This looks serious.

Have botrytis spores been found to be carcinogenic? Is Drosophila suzukii reaching plague proportions around Langon? Has Sémillon acquired a mysterious auto-immune disease?

Not exactly. The accompanying dossier made clear that it was all about a projected high-speed rail line linking Bordeaux with Toulouse and (separately and subsequently) with Dax. So the trains are going to go thundering right through the middle of Sauternes? Er, no; they are in fact steering a wide berth around both Sauternes and Barsac (see the plan above), and are unlikely even to rattle the window shutters at Yquem. The only vineyards to be directly affected lie in Graves (including those of Ch Méjean and Ch Le Tuquet), plus a little of the least propitious land in Pessac-Léognan, to the eastern side of the A62 motorway. So why the drama?

Mist, in a word. All wine students soon learn that the magic felicity in the Sauternes landscape is the cool river Ciron (cool because it has flowed for most of its course through the Landes forests) meeting the warmer Garonne (which has laboured across the wide and sunlit Marmande plain). The contrast reaches its apogee at summer’s end, and the result is misty mornings followed by sunny afternoons: ideal conditions to maximise the growth of botrytis. “It’s not a legend,” says Bérénice Lurton of Ch Climens, “but the truth. The Ciron is vital for Sauternes.”

The existing plan is that the two new branches of rail line will meet more or less at the point at which the A65 motorway now crosses the Ciron, and then sweep up to the west of the little valley on the way to Bordeaux. The Sauternais allege that the fragile and rare riparian forest environment of the Ciron will be damaged by the works needed to create the line, as well as by the corridor created by the new line itself – with the result that the region may experience less mist and more frost. “Devastated classified zones, pollution, a huge building site, infernal noise, a waste of energy, and all that to gain a few minutes on rarely used rail journeys, for unaffordably expensive rail tickets. This project,” the campaigners thunder, will be “ruinous for the region’s economy, shameful for its ecology, and fatal for its vineyards.”

Let me step back a little and explain why I take a keen personal interest in all of this. My biggest professional shock since arriving in Montpellier almost five years ago is finding just how difficult it is to get to Bordeaux from here. Jump on the plane? There isn’t one. Jump on the bus? There isn’t one. Get the TGV? There’s no direct link. The choice is between a 485-km road journey (five hours, however you do it) or getting the inadequate, delay-prone ‘express’ train which labours all the way from Nice to Bordeaux a few times a day (and which takes as long as the road journey).

And it doesn’t just affect winos like me. Nice-Bordeaux is the major southern axis of the entire country, linking France’s second, fourth, fifth, eighth and ninth largest cities, and it is poorly served by France’s existing infrastructure, most of which seems designed to help Parisians take their summer holidays and skiing holidays with maximum ease. The section between Toulouse and Bordeaux is particularly feeble (quicker by car than by train). I and my fellow sufferers on this line can promise the Sauternais that this is not a ‘rarely used’ rail journey, nor are the tickets ‘unaffordably expensive’. When I made the journey from Montpellier to Bordeaux by rail in September 2014, the return ticket cost €97.8, whereas when I made the same journey in a small car in December 2014 the fuel alone cost €100.05 and the road tolls a further €73.60.

I can see, in other words, the compelling need for these rail works, and I’m disappointed to learn that they won’t be completed before 2024. I also, though, adore Sauternes, and am no less aghast at the idea that the mist might run out. So which side of the argument am I on?

In cases like these, you have to read the arguments, and then decide which seem most credible. According to the RFF (Réseau Ferré de France – the government-owned, track supply and maintenance company), the entire Ciron section will be a raised track, enabling existing drainage channels to continue unimpeded, and will cross the river itself via two large viaducts. It also points out out that the finished track will have a minimal impact on the river as a whole, most of which lies far upstream of the crossing (the full length of the Ciron is 96.9 km). There will be ‘ecological corridors’ for wildlife. The course of the track is seldom less than 5 km from the river itself, and a full 20 km from Sauternes’ vineyards.

The idea that this railway line will change the temperature of the river water strikes me as improbable, since almost all of the existing forest will remain in place. A railway track never ‘eats into’ its broader environment in the way that roads do. Once completed, the countryside closes around it again harmoniously, as anyone who lives or walks near a railway track in a rural location will know. And far from being ‘ruinous for the region’s economy’, better rail links from the south and the east will greatly benefit the regional economy.

I contacted the CIVB’s president, Bernard Farges, shortly before Christmas about this issue. “The CIVB doesn’t have a position for or against major infrastructure projects,” he told me. “Our concern is terroir.” On that basis, it shared the concerns of the Sauternes growers, and had made a submission to the public enquiry calling for a more thorough scientific analysis of the impact of the project on the Ciron valley. That seems sensible.

The wine community doesn’t exist on a planet of its own, nor does it have any kind of privileged right to rural space (wine grapes are a luxury, not a staple food crop). It’s perfectly legitimate to defend one’s economic interests, but in the end questions of this sort must be decided by reasoned analysis. Let’s hope we can both have the railway line and keep the mist.

Written by Andrew Jefford