Lyon's Earliest Aqueducts

The Romans liked water. Public baths... continuous running drinking fountains... many private homes having running water... public toilets. Bath houses were centres for social engagement... where commercial agreements were settled... family matters like weddings and celebrations were discussed... community health and grooming all occurred in the bathhouses... and, of course, political posturing all took place. Typically, every citizen was given equal access to the bathhouses. Seeing their political leaders in the 'nuddy' on a regular basis would dispell any 'halo effect' that we sometimes now bestow on our politicians. Lyon was a greenfield site for a Roman city... so water supplies and aqueducts were part of of the planning... part of the criteria in selecting the location.

To get the required volume of water into Lyon the Romans built an aqueduct from springs in mountains some 48 klms away (as the crow flighs)... it followed a sinuous path...   at 85 klms...  around all the bends... it was the longest known of the Roman aqueducts. Its route has been retraced in detail, following the numerous remains. 

Wikipedia says the Lyon aqueduct "draws upon the whole repertory of Roman techniques of aqueduct building, taking a slope that averages 0.1%, or a meter every kilometer. There are 73 km of covered ditches laid with a concrete culvert 3 m high and 1.5 m wide, which is sunk as deep as 4 m beneath the land surface. The aqueduct passes through 11 tunnels, one of which, near Mornant, is 825 m in extent. Access for cleaning and repairs was through manholes at 77 m (253 ft) distances. There are some thirty stretches in the open air. There are ten stretches raised on walls and arches, which provide the most spectacular visible remains of the aqueduct."

The Romans used piping to solve some of the geographic challenges of the aqueduct... and used lead... their favourite plumbing material. No doubt the aqueduct saved countless thousands from gastrointestinal illnesses... that more than made up for the proportion that suffered from lead poisoning. 

We had to have a look... and made it a stop on our drive from Lyon to Avignon. The engineering achievement was remarkable... but more remarkable still..., was the style and dressing placed on the aqueduct. The dressing must have added materially to the construction effort. It seems that the aqueduct had two purposes... bringing water to Lyon... and showcasing the technical-engineering excellence of the empirical power.