The work of Claudius in the harbour is mentioned in an inscription from 46 AD. It was found in Portus in 1836, reused as pavement. Originally it may have been in the attic of an arch. It informs us that Claudius hoped to reduce the risk of inundations in the city of Rome by digging channels from the Tiber to the sea.
TI(berius) CLAVDIVS DRVSI F(ilius) CAESAR
AVG(ustus) GERMANICVS PONTIF(ex) MAX(imus)
TRIB(unicia) POTEST(ate) VI CO(n)S(ul) DESIGN(atus) IIII IMP(erator) XII P(ater) P(atriae)
FOSSIS DVCTIS A TIBERI OPERIS PORTV[s]
CAVSSA EMISSISQVE IN MARE VRBEM
INVNDATIONIS PERICYLO LIBERAVITTiberius Claudius, son of Drusus, Caesar
Augustus, conqueror of Germany, chief priest,
tribune 6 times, consul elect 4 times, imperator 12 years, father of the fatherland,
having led canals from the Tiber because of the work
at Portus, and having led them out to the sea, freed
the City from the danger of flooding.EDR094023.
The inscription on display near the basin of Trajan in 1895. Photo: British School Rome.It seems that Claudius ordered the digging of two channels. One, the Northern channel, has been identified on aerial photos and confirmed by geophysical research by the Portus Project. It runs from the Tiber to the secondary entrance to the basin of Claudius [10]. The second is the Trajanic channel (Fossa Traiana) that, in spite of its modern name, was most likely the work of Claudius. It branches off from the Tiber at a spot called Capo due Rami ("Head of the two branches"). It leads to the sea, but halfway a communication channel branches off towards the Inner harbour ("darsena").
Capo Due Rami ("Head of the two branches"), where the Fossa Traiana (to the right) branches off from the Tiber (to the left).
Seen from the north. Photo: Jan Theo Bakker.Inundations remained a problem after the digging of the canals by Claudius. A badly preserved inscription from the years 102-109 AD mentions work by Trajan on a channel and inundations of the Tiber:
[Imp(erator) Caes(ar) divi]
NE[rvae f(ilius) Nerva]
TRA[ianus Aug(ustus) Germ(anicus)]
DAC[icus trib(unicia) pot(estate) ---]
I[mp(erator) --- co(n)s(ul) --- p(ater) p(atriae)]
FOSSAM [restitui iussit? fecit?]
[q]VA INVN[dationes Tiberis]
[ad]SIDVE V[rbem vexantes]
[rivo p]EREN[ni instituto arcerentur]Marble slab. Provenance unknown.
San Paolo fuori le mura. EDR094033.This may have been the Canale Romano (see "Harbour of Trajan - Temple of Portumnus, Via Portuensis and aqueducts"). The channel is mentioned by Pliny the Younger in one of his letters, dated to 108-109 AD:
Tiberis alveum excessit et demissioribis ripis alte superfunditur. Quamquam fossa, quam providentissimus imperator fecit, exhaustus premit vallis, innatat campis, quaque planum solum, pro solo cernitur. The Tiber has overflowed its bed and deeply flooded its lower banks, so that although it is being drained by the canal cut by the Emperor, with his usual foresight, it is filling the valleys and inundating the fields, and wherever there is level ground there is nothing to be seen but water. Pliny the Younger, Epistulae 8,17,1-2. Translation B. Radice.
