Aqua Traiana

For the photo's, see below
As suggested by its name, Trajan built the Traiana. Before its construction, the Trastevere region depended on aqueducts across the river (Aicher, 1995:44). The literature and study of the Aqua Traiana is somewhat limited because it was established after Frontinus. Inscription CIL 6.1260 (See Chapter 3.5 of the thesis XXX), however, does indicate that it was established in AD 109. Further evidence commemorating its establishment is found on a sestertius coin (see photo) dating from the Trajan's fifth consulship and by a lead 'fistulae' found on the Esquiline near the baths of Trajan bearing the markings THERM(ae) TRAIAN(i) and AQ(ua) TR(aiani) (Evans, 1997:131). It is also mentioned in the 'Liber Pontificalis' in the life of Felix II (AD 355-8) and in an inscription which records repairs to it by Belisarius (Ashby, 1935:299). This inscription seems to have been lost since the seventeenth century.

Source and course
Its source was taken from the high-quality springs located near Trevignano, northeast of Lake Bracciano. Its course generally ran south following the high lands of its region. One section of its conduit was discovered in 1912 underneath the American Academy and is still accessible today. Another discovery was made in 1990 and 1991 in the Via Giacomo Medici. Remains of a mill powered by the aqueduct were found at this location. Other evidence suggests that a terminal 'castellum' of the Traiana resided under the present day casino of the Villa Spada. The Traiana's estimated length was 35 to 60 km. A more accurate figure is difficult due to the lack of written sources and material remains.
Distribution
The height of the aqueduct and its point of entry made it possible for the Traiana to distribute water to all fourteen districts in Rome. The point of entry, above the Transtiber, indicates that its primary role was to service the needs of that district. This area had grown rapidly during the first century and required more water to satisfy the district's needs. The Appia and the Alsietina would have been too low to have fulfilled this requirement.
The necessity of supplying his Baths with water seems to have been met by Trajan with the introduction of the Aqua Traiana. Epigraphical evidence suggests that a certain amount was distributed throughout the city and either supplied the new Baths directly or freed water from other aqueduct lines for that purpose (Anderson, 1985:508).
Water-mills
Recent excavations on the Janiculum have lead to speculations about the use of water mills on the Aqua Traiani. An excavated complex in the region shows that location of water mills, using undershot wheels at the point where the Traiana's gradient starts to increase but before it becomes steep enough to use overshot wheels, looks like an attempt to squeeze in the maximum number of mills possible in this area. The course of the Traiani and Alsietina follow the peculiar configuration of the Janiculum salient traced by the Aurelian Walls at this location (Wilson, 2002:13). Interestingly, Procopius tells us that the line of the Aurelian Walls on the Janiculum was intended to protect the water-mills there.

The Traiani was the last great aqueduct built in Rome. Frontinus' (87.2, 88.1 and 89) praise of Trajan seems well justified when considering Trajan's foresight in building the first aqueduct on the western side of the Tiber, and using it to supply the Eastern side. This was opposite of the usual practice (Evans, 1997:132).

From E.J. Dembskey: The aqueducts of Ancient Rome" (master thesis 2009)


HOME More literature on more aqueducts Last modified: January, 2010 - Wilke D. Schram (w.d.schram@romanaqueducts.info)


Via del casale di S. Pio V
Via Aurelia Antica
Near the casino Corsini
Possible route

Under the American Academy
Map of Parker 1876
Denarius