Aqueduct du Gier

• The Aqueduct du Gier, was a Roman Aqueduct in Gallia Lugdunensis, which brought water 26 miles (42 km) to Lyon.
• It used four Inverted Siphons and eleven tunnels and was completed in c. 50 CE.

Inverted Siphon

• Instead of building bridges across the river valleys, the aqueduct used four inverted siphons to cross the valleys of the rivers Dureze, Garon, Yzeron and Trion.
• The water would enter a water tank in a sunken Castellum or tower before flowing through pipelines that descended to the valley floor.
• The pipes then crossed over each river on arches and rose up the other side to another water tower that was slightly lower than the first tank.

Aqueduc du Gier