Ancien aqueduc de Pontgouin à Versailles (également sur communes de Maintenon et Pontgouin)
MonumentHidden Treasure
A colossal vestige of Louis XIV's great dream, this unfinished aqueduct crosses the Beauce over several kilometres: a monument to solar ambition, set in stone and earth.
© Wikimedia Commons / Wikipedia
History
Between Chartres and Maintenon, in the heart of the Beauceron plain, a ghost of hydraulic engineering still stands in the agricultural landscape: the aqueduct from Pontgouin to Versailles, a monumental vestige of the most ambitious - and craziest - project of the reign of Louis XIV. Listed as a Historic Monument since 1934, this unfinished work is one of the most remarkable reminders of the excesses of Versailles, far from its gardens and gold. What immediately strikes visitors strolling around Berchères-Saint-Germain and Maintenon is the telluric power of these earthen levees that sculpt the flat Beauce horizon. These monumental embankments, sometimes several metres high, are not simply embankments: they conceal within them a whole network of sophisticated engineering structures - tunnels for roads, hydraulic siphons, aqueducts spanning the natural valleys. It's a veritable underground city in the service of water, abandoned before it even sinks. The visitor experience is that of an open-air monument, a journey of several kilometres through tall grass and fields of wheat, where the imagination makes up for what time has erased. There is no pomp or gilding here: the limestone, the beaten earth and the silence of the plain create an austere and moving picture. Hikers and technical history buffs will particularly appreciate this off-the-beaten-track tour, far from the tourist crowds. The Boizard locks and dyke, attributed to Vauban, add a military and civil engineering dimension to the whole, reminding us that the greatest engineers in the kingdom were mobilised for this titanic undertaking. Today, these structures still stand the test of time, silent witnesses to a royal will that war and death were to shatter before its completion.
Architecture
The aqueduct from Pontgouin to Versailles is not an aqueduct in the Roman sense of the term - a series of slender arches crossing a valley - but a complex hydraulic system incorporating several complementary types of structure. The most visible element is the earth embankment that runs for several kilometres across the Beaucheron plateau, reaching impressive heights and widths in places. Designed to carry an open canal with a slight slope towards Versailles, this embankment is in itself a feat of seventeenth-century earthworks. Buried beneath these masses of earth, the royal engineers built a whole network of structures in local limestone: vaulted tunnels allowing existing paths to pass under the levee without interruption, hydraulic siphons allowing small streams to cross the embankment without creating leaks, and veritable miniature aqueducts evacuating water from valleys intercepted by the earthworks. The construction uses the masterful techniques of French military masonry, with carefully proportioned barrel vaults. The Boizard locks and dyke, attributed to Vauban, represent the most sophisticated component of the complex. Designed to regulate the flow of water and provide a sufficient reserve of water, these structures bear witness to the hydraulic engineering of Marshal de Vauban, best known for his fortifications but equally at ease in the field of civil engineering. The materials used are essentially Beauce limestone and brick, in the building tradition of the Grand Siècle.
Related Figures
Louis XIV — commanditaire du projet, qui souhaitait alimenter les fontaines de VersaillesVauban — ingénieur militaire attribué aux écluses et à la digue de BoizardLouvois — ministre de la Guerre ayant coordonné la mobilisation des régiments sur le chantierJules Hardouin-Mansart — premier architecte du roi, impliqué dans la planification globale des eaux de VersaillesThomas Gobert — ingénieur hydraulicien royal ayant travaillé aux projets d'adduction d'eau de Versailles
