Augustus's Canal, Ravenna

Fossa Augusta

CanalItalia · Ravenna, ItalyBuilt 20 BCE

About

Augustus ordered this four-mile channel cut in the 20s BCE to link Ravenna to a new naval harbor down the coast at Classe, home port of his Adriatic fleet. The canal fed a Po tributary's fresh water down to the shore, and shipyards eventually lined some 22 kilometers of its banks. The classis Ravennas it served held up to 250 warships and 10,000 marines. Centuries of silting have since pushed the ancient coastline nine kilometers inland, but in 117 CE the Fossa Augusta still ran open water straight from Ravenna to the sea.

What happened here

Cut to shorten a journey, to bypass a river mouth that silts, or to drain ground that floods. Digging is done by soldiers or by contracted labour in seasons when the water is low, and the spoil is banked along the sides to make a towpath. Barges are hauled by men or oxen, moving grain, stone, timber and wine at a fraction of the cost of the same distance by road. Sluices control the level where the canal meets a tidal river. Maintenance is endless — silt, weed and collapsed banks — and a canal that is not dredged returns to marsh within a generation. Towns along it grow fast, and the tolls charged at each end are worth having.