Tacked on to a sheer rock face, a series of weathered wooden channels led our hiking group across vertical cliffs at a dizzying 1,200m. It was only thanks to the mounted guardrails and safety nets that we could walk the 6km-long trail – known as Torrent Neuf – at all. The 15th- Century Rhône Valley farmers and vintners who dared to build these suspended irrigation channels had nothing more than a shovel, pickaxe and worn ropes. It was a perilous job that cost lives – but spared one corner of Switzerland from near drought.
Switzerland may be dubbed "Europe's water tower", but one region, the Valais in south-western Switzerland, has historically endured aridity exacerbated by the foehn, a notoriously dry, warm wind found here.
Bordering Italy to the south and France to the west, the L-shaped region stretches from the mighty Matterhorn to Lake Geneva. The alluvial soils of lower Valais' gentler slopes are carpeted with fruit orchards, where some 70 varieties of apricots ripen in the region's Mediterranean-like summers. Meanwhile, in the exposed alpine pastures of German-speaking upper Valais, native breeds like Valais Blacknose sheep and horn-locking Herens cattle clang their bells in the shadow of the Alps. These same 4,000-plus metre peaks protect central Valais' terraced vineyards that green the dramatic Rhône Valley's south-east facing slopes. This is the heart of Switzerland's boutique wine industry, where endemic varieties like Amigne and Goron de Bovernier have put Swiss vintages on the world map.
Despite being surrounded by some of Switzerland's wettest mountains, the sun-scorched, glacier-carved region receives just 500mm of rainfall a year, presenting a unique engineering challenge for irrigation. Cue gravity-defying bisses, designed to divert glacial meltwater from mountain streams to parched pastures and vineyards at lower elevations. To this day, 200 of them totalling 1,800km in length supply water to 80% of the Valais' irrigated land.