Bordeaux is naturally associated with the Garonne, but historically the city developed along the banks of two smaller rivers which ran into the Garonne: the Devèze and the Peugue. Both streams continue to flow but, in central Bordeaux, have been driven underground. Invisible Bordeaux decided to follow the course of the Devèze to find out what remains of this significant river today.

The Devèze emerges from the undergrowth in Mérignac, just east of the runway of Mérignac airport. The source is easy to locate: a prominent permanent advert for the Sexy Center sex shop can be seen nearby! Whilst in its infancy, the Devèze runs behind a number of nondescript office buildings and bus depots. A path runs alongside it but there are a number of obstacles along the way… cyclists take note!

The point where the Devèze emerges from the ground, easily located (possibly even from planes coming in to land)
thanks to the Sexy Center ad nearby!

Less than one kilometre downstream, next to a Siemens facility, the river disappears underground for the first time, although it soon becomes clear that the enormous pipes go on to feed an artificial lake, or rather the Beaudésert “bassin de stockage des eaux de pluie” (rainwater storage reservoir), also known to anglers as Étang Innolin. This scenic expanse of water is part of a wider network of large plots designed to regulate the flow of streams and rainwater to avoid flooding in central Bordeaux (a standalone subject that features elsewhere on the blog). 

The Siemens offices where the Devèze disappears underground before flowing into Étang Innolin.

The Devèze is subsequently channelled back underground and passes below the Rocade ringroad (more or less where a Buffalo Grill restaurant can be seen) and then into central Mérignac. At this stage it flows through an area where leafy forests have continued to be maintained, and yet there is no sign of the Devèze on the surface. It does later re-emerge though, hemmed in by concrete walls but sided by a short, scenic pedestrian-only walkway which has, appropriately enough, been called “l’aire piétonne la Devèze”. 

The approximate points where the Devèze passes, unnoticed, under the Rocade ringroad and central Mérignac, before re-emerging and getting its own footpath!

The Devèze then enjoys a starring role in the Parc de Bourran, the grounds of a mansion where vines were cultivated for many years until a landscape gardener, one Louis Le Breton, overhauled the terrain towards the end of the 19th century. Le Breton made use of the Devèze to create a large pond which can still be seen today. The Devèze also feeds a spectacular artificial waterfall before flowing under a “Medieval” bridge, installed in 1890 as part of Le Breton’s designs, although it is uncertain whether the bridge came from elsewhere or whether it was built specifically for Parc de Bourran.

The "Medieval" bridge.

The Parc de Bourran waterfall, pond and the spot where the Devèze makes a discreet exit from the park.

From the park the Devèze flows down large pipes and through a small area of overgrown greenery, before being conducted beneath a railway line. This is, from what I can make out, the last we see of the Devèze at ground level (and it is not at its most beautiful by now: during the short time I was there the sight of two rats reminded me that the river was used as a natural sewer for many years). 

The last sight of the Devèze before having to resort to street-names to plot its course.

From then on, plotting the course of the Devèze was a case of cross-referencing between Googlemaps and documents produced by the greater Bordeaux authority (Communauté Urbaine de Bordeaux, CUB), although there are other tell-tale signs that the Devèze is never far away: shortly after the railway bridge, still in Mérignac, come Rue de la Devèze and Square de la Devèze. These are followed by street-names that serve as a reminder of the water-reliant trades that used to be there, such as Rue des Lavoirs (wash-houses) and Rue des Teinturiers (textile dyers). Every now and then, the sound of fast-flowing water can also be heard through manhole covers. The Devèze enters Bordeaux proper along the southern edge of Chartreuse cemetery. There too, the street-name hints at what lies below: we are on Bordeaux's Rue de la Devèze. 

In past times, from here the Devèze flowed more or less in a straight line towards the area where Saint-Pierre church can now be seen. This was where the city’s earliest port was located up until the 10th century, by which time the waters of Port Saint-Pierre had become too clogged up with mud.

Further upstream, the Devèze was partly diverted towards the Peugue, and the port area was gradually built over. Near Place Saint-Pierre, on Rue de la Devise (a name by which the Devèze was also known), an information panel now refers to the bygone presence of the river. Meanwhile, the commercial heart of the city developed around the Peugue (most notably around what is now Place Fernand-Lafargue) but the Peugue riverside areas became notoriously rough and insalubrious. To eradicate this, throughout the 17th and 18th centuries work was carried out to drive the flowing water underground for good. The channelling operation was eventually complete in 1868.   

Rue de la Devise and Place Saint-Pierre, where the city's earliest port was located, fed by the Devèze.

The Devèze’s permanently diverted course now takes it through the Mériadeck quarter ahead of meeting up with the Peugue - which has similarly made its way into Bordeaux from Pessac - around the junction between Cours d’Albret and Rue des Frères Bonie. Once again, from then on, tracking the course of today’s dual underground river involves map-assisted guesswork, although it is generally acknowledged that the waters flow under Cours d’Alsace-et-de-Lorraine through a pipe which is 4.80 metres wide and 3.30 metres high. The presence of the merged rivers is even highlighted in a bas-relief sculpture that can be spotted on the corner of the Cours and Rue Sainte-Catherine: the sculpture features the goddess Divona (the goddess of divine sources, from which the name Devèze derives) and a male counterpart (representing the Peugue, which derives from the Latin pelagus, meaning the overflowing waters of a river). 

The approximate point where the Peugue and Devèze meet, as later celebrated in this bas-relief.

The two streams complete their course with a man-managed concrete-and-metal outlet on the banks of the Garonne, releasing water into the city’s main river as and when deemed necessary.  

An unceremonious end to the trek, near the Pont de Pierre.

In all, the waters of the Devèze have flowed 10.45 kilometres from the Mérignac source to the banks of the Garonne. Hidden away for much of that time, it is now difficult to conceive how vital the river once was to the city, as testified by the 4th-century Latin poet and teacher Ausonius who wrote this about the Devèze: "Hail fountain of source unknown, holy, gracious, unfailing, crystal clear, azure, deep, murmorous, shady, and unsullied. Hail, guardian deity of our city, of whom we may drink health-giving draughts, named by the Celts Divona - a fountain added to the roll divine!"  

You can also enjoy a video version of this feature:

Click here if video does not display properly on your device.

• Find it: full course of Devèze river plotted in blue on Invisible Bordeaux map along with individual markers for the source, Étang Innolin, Parc de Bourran, Place Saint-Pierre and the outlet on the Garonne.
• Big thanks to Michel D. who informed me about the Ausonius poem (see p284 here).

We find ourselves in Pyla-sur-Mer, and tucked away in one of the quiet residential districts, just a few hundred metres inland from the waters of the Bassin d’Arcachon, is a curious church: la Chapelle Saint-Esprit.

The chapel is a seasonal operation, with masses held there solely during the summer holiday period, in July and August, at hours which are part of a rota that includes five other churches in and around Arcachon. What sets la Chapelle Saint-Esprit apart from most churches is its unusual seating plan, which includes a number of pews which are permanently stationed in an area which, though under cover, is very much out in the open air, so that the congregation can combine prayers, hymn-singing and worship with the pleasant sensation of experiencing the cool breeze blowing through the surrounding pines.

All very unusual, but not unique in the area. There are in fact other open air chapels across Arcachon Bay in Cap Ferret (Chapelle de Piraillan) and further up the coast in Longarisse, near Lacanau (Chapelle Saint-François d'Assise). Back in Pyla-sur-Mer, the church was completed in 1975 to the modern designs of the Parisian architect Xavier Huvelin. Locals also played a large part in the project. On a plaque, the Labbé family is credited as having been the “generous” instigators of the chapel, which was built on land donated by the Maysonnave family.

The plaque also harks back to the visit of Bordeaux archbishop Monseigneur Maziers, whose decision it was to give the chapel its name (which means “of the Holy Spirit”). One Robert Marcou is referred to as parish priest although contemporary accounts claim that many early masses were led by clergymen who just happened to be on holiday in the area at the time!

Further information about the chapel is surprisingly hard to come by. One interesting titbit is that the elegant triangular belltower had to be totally rebuilt in 2003 after the original was brought to its knees by an army of hungry house longhorn beetles (Hylotrupes bajulus, or simply “capricornes” in French). And prior to this modern construction, a small barn-like wooden chapel had stood more or less in its place since 1935.

The original 1935 chapel (source: Mémoire en images, Pyla-sur-Mer).

It would be great to know a little more about this peculiar place of worship and its open-air gatherings… it may be a case of returning there for a mass over the summer! 

> Find it: Allée de la Chapelle, Pyla-sur-Mer.

> Thanks to Harvey for providing information about the other open-air chapels in the region!

In the Pierroton district of Cestas, just off the main road that leads from Bordeaux to Arcachon, a monument to the agronomist François Jules Hilaire Chambrelent can be seen. It was Chambrelent’s work throughout the 19th century that went some way towards making much of les Landes of south-western France the environment we are familiar with today.

In the past, it had been a very different story. South of Bordeaux, the inland area was a succession of vast, barren plains that were frequently flooded. This extensive sandy marshland, which became known to many as the “French Sahara”, was a particular challenge to many pilgrims as they headed south towards Santiago de Compostela in north-western Spain.

Towards the end of the 18th century, the engineer Nicolas Brémontier (Inspecteur General for Ponts et Chaussées, Bridges and Roadways) had shown that it was possible to use trees to hold back the dunes of the Atlantic coast. Mass plantations of maritime pines (Pinus pinaster) followed – this local species boasts strong roots which fix and consolidate the sandy land at its base, and when its needles fall they form a “carpet” which slowly evolves into fertile and solid soil. This technique was to inspire fellow engineer Chambrelent in the following years…

Source:
parc-landes-de-gascogne.fr

Chambrelent was born in 1817 in Martinique. He studied at École Polytechnique and École Nationale des Ponts et Chaussées in Paris. Between 1848 and 1865, he was based in Bordeaux as an engineer for the Gironde hydraulic work department. He subsequently took up other positions in the Alps before returning to Bordeaux in 1873 as head of the hydraulic unit and then Inspector General for a three-year period ahead of his retirement in 1882.

In 1849, Chambrelent had personally acquired 500 hectares of land in Cestas (in a part of the town known at the time as Saint-Alban). His self-defined task was to establish how forests might develop on land that alternated between periods of flooding and periods of drought. His research showed this could be achieved by breaking down the top level of soil and then deploying a large-scale network of ground-level irrigation channels, thus ridding the land of otherwise stagnant water. The soil could then be used to accommodate maritime pines and oaks (Quercus suber, or cork oak,  and Quercus ilex, or holly oak).

In case that all sounds a bit too simple, rest assured, Chambrelent later provided more detailed information about his findings in the 1887 book “Les landes de Gascogne, leur assainissement et leur mise en culture. Exploitation et Débouchés de leur produits.”, and in the specialist review Annales des Ponts et Chaussées. Chambrelent had also presented his findings at the 1855 Universal Exhibition in Paris, which did much to raise his profile and indirectly resulted in Napoleon III awarding him the Croix d’Officier de la Légion d’Honneur. Then, in 1857, a law largely based on Chambrelent’s recommendations was passed and provided the blueprint for the “assainissement et mise en culture des Landes de Gascogne”. The stage was set for the transformation of the area into the landscape which remains today.

"He cleaned and embellished the moors and brought ease to a deprived area."

Chambrelent basked in glory but for many the success had a bitter taste. Chambrelent had been inspired not only by Brémontier but by fellow Ponts & Chaussées engineer Henri Crouzet, and the latter’s essay on “La transformation des Landes de Gascogne”. At the 1855 Exhibition, while Chambrelent collected the plaudits, Crouzet went home with a lowly medal in recognition for his “services to the event”. Other unsung pioneers include dune-owners Guillaume and Louis Mathieu Desbiey who had carried out similar research one hundred years earlier but whose work was also left in the shade by Brémontier and Chambrelent.

It is therefore Chambrelent who is celebrated by the monument, which was officially unveiled on September 11th 1907. It had been funded by the Touring Club de France, the association which sought to promote and develop “tourism in all its forms” between 1890 and its demise in 1983.

The monument stands just a few hundred metres away from the property where Chambrelent carried out his life-size research. The mansion which he built there in 1863 still remains; it and the surrounding land were later passed on by the Chambrelent family to the French State and are now home to the Unité Expérimentale Forêt Pierroton, part of France’s national agronomic research institute (INRA, Institut National de la Recherche Agronomique).

Meanwhile, it was in Paris that Chambrelent died in 1893, although he was buried in a neo-classical vault at Chartreuse cemetery in central Bordeaux. Twenty kilometres away in Cestas, his influence continues to be acknowledged though: as well as the roadside monument, his name has been given to a housing estate and the local football pitch!

The grave chapel in central Bordeaux where Chambrelent is buried.

The entrances to Chambrelent football pitch and housing estate in Pierroton (Cestas).

However, Chambrelent’s most lasting legacy will be the massive forests (and irrigation ditches) that cover 900,000 hectares of land throughout south-western France. The large swathes of green that can be seen on satellite photos of the area are therefore, in many ways, largely man-made… and François Jules Hilaire Chambrelent is one of those men.

How the Landes gradually turned green during the 19th century (source: INRA), and (right) how the area looks today on Google Earth.

• Find them: Chambrelent monument, Unité Expérimentale Forêt Pierroton (INRA), housing estate and football pitch, Pierroton, Cestas ; Chambrelent’s grave, Bordeaux.