Les Vans, the underground Bourdaric
This documentary covers a foray that has been a long time coming: a visit to the Bourdaric underground river in Les Vans, Southern Ardèche. Honestly, it’s nothing to write home about, but like many other underground rivers documented here, it has its own quiet charm and is worth the look. The Bourdaric is a tributary of the Chassezac, which flows into the Ardèche, which in turn flows into the Rhône. Its underground length is approximately 950 meters. Anyway, enough talk—let’s head underground.
The Route
The upstream entrance is located beneath Rue du Quai, under the medical center. From there, entirely underground, it passes beneath the roundabout, in front of the tourist office, past "La Petite Boulange," and the Crédit Agricole (following Avenue Fernand Nadal), then along the Clairette roundabout. The downstream exit is located right next to the Carrefour supermarket.
The Bourdaric feeds the fountains of Les Vans. This creates two networks of streams forming underground tributaries, the names of which are unknown to us. these wind through sections with fairly low ceilings. Everything suggests that at least one of them reaches the small theater on Rue du Couvent and its washhouse. A steel door to the right of the theater clearly provides access to the underground network, which may be independent. As for the Barre stream, it flows into the Bourdaric near Carrefour through a large, elevated pipe.
Architecture and History
Both ends of the Bourdaric—by the medical center and Carrefour—are of little interest. They consist of large, modern, and bland concrete galleries. The downtown section is far more interesting, featuring older construction where you can still make out the arch of an ancient bridge.
Before 1810, the river meandered through Les Vans and was crossed by multiple bridges. The covering of the Bourdaric dates back to that era, under mayors Jauffre and Colomb. The river was covered in the town center to save space. During this period, an ingenious system was implemented to feed the town's fountains. Unfortunately, these systems are now lost, and the fountains are powered by pumps. The covering works lasted 40 years.
Industrial Use and Sanitation
The water diversion also served to power olive mills, tanneries, spinning mills, and gardens. Later works were carried out for sanitation purposes. Consequently, one can see that all wastewater discharges (and there are many!) have been diverted into a collector. A few "nasty" discharges still remain.
It has been noted that during a flood, Hubert Froment had to remove massive blocks from the gallery. This was reportedly achieved using a manual winch (tire-fort) and sheet piling.
We now invite you to explore this lonely and pleasant underground river!
