Timeline

Heritage classified

Key figures

Origin and history

The remains of the aqueduct reservoir known as the Angelique mark the culmination of the Gier aqueduct, one of the four ancient aqueducts serving Lugdunum (Lyon). With its 86 km, it is the longest and best preserved, capturing the waters of the Gier, tributary of the Rhône. Its construction, long attributed to Claude or Hadrian, is now dated to the reign of Trajan (around 110 AD) thanks to dendrochronological analyses, although a completion under Hadrian is not excluded.

The lake passes through the Loire and Rhône departments, using various techniques: bridge-aqueducts, siphons, tunnels and trenches. His remarkable works include Beaunant's bridge-siphon, the Réservoir de Soucieu, and the arches of the Air Plat in Chaponost. These remains, classified as historical monuments at different periods (1875, 1912, 1930, 1986), illustrate Roman engineering, with opus reticulatum trimmings and waterproof pipes in opus signinum.

The dating of the water pipe was debated: lead pipes stamped "LAVD AVG" (Claude) and the "stone of Chagnon" (1887), bearing an edict from Hadrian (117–138 A.D.), fed contradictory hypotheses. The discovery in 2018 of wooden formwork dated 110 A.D. confirmed a construction under Trajan, while leaving a doubt about a finalization under Hadrian. The inscription of Chagnon, similar to that of the "stone of the Rieu" (1996), prohibits ploughing, sowing or planting near the lake, taking over an Augustine law.

The study of the aqueduct began in the 16th century with Lyon scholars like Pierre Sala and Symphorien Champier. In the 18th century, in the face of water shortages, the Académie de Lyon revived research, notably with Guillaume-Marie Delorme (Research on the Aqueducts of Lyon, 1760) and Paul de Gasparin, who mapped the work in 1834. Germain de Montauzan, in his 1908 thesis, laid the foundations of modern research, describing its layout, techniques (siphons, looks) and its estimated flow rate of 15,000 m3/day.

Among the most spectacular remains, the Jurieux canal bridge and the siphon of the Yzeron (classified in 1900) bear witness to Roman technical daring. Beaunant's siphon, with its hunting tank and concrete crawling, crossed a depression of 3 km. Sections such as the arches of the Air Plat (Chaponost) or the Granchamp Wall (Suicieu-en-Jarrest) show a rare cross-linking in France. Recent restorations, such as those of Chaponost Arches (2009–2010), have preserved these structures.

In 2018, the "Loto du Patrimoine" was awarded to the "Lyon", Sainte-Foy-lès-Lyon, Soucieu-en-Jarrest" and was classified as historical monuments in several municipalities. Its layout, marked with glances, tunnels and bridges, remains partially visible, offering an exceptional testimony of Roman hydraulic engineering in Gaul.

External links