“Cloaca Circi Maximi”

One of Rome’s major drains, the “Cloaca Circi Maximi” ran through the *Circus Maximus and the *Forum Bovarium, to discharge into the *Tiber; it collected waters from the valleys of the Circus Maximus, *Via Appia and the Colosseum (s.v. *Vallis: Circus Maximus, Vallis: Via Appia, Vallis: Colosseum). The drain must have been installed at an early date, since it was necessary to make the swampy lowlands of the Circus Maximus valley suitable for racing (Humphrey 67; Ciancio Rossetto, LTUR 273); most believe the sewer followed the path of an ancient watercourse (Holland 347-48; Lanciani 280-82). Archaeological evidence for the drain is scarce. Brief traces of an opus quadratum drain were recovered at the base of the *Caelian, near the foot of the *“Clivus Scauri” (Colini; Lanciani, FUR pl.25); these, as well as sewers running below the *Via di S. Gregorio and the intra-urban continuation of the Via Appia, probably connected to a central drain that ran beneath the Circus proper. Though recent excavations in the Circus Maximus sought to locate and reactivate the drain (in hopes of lowering the restrictively high water-table in the region), their efforts have not yet borne fruit (Ciancio Rossetto, LTUR 273; ead. 1985; Humphrey 110). The “Gran Cloaca” depicted by Lanciani (FUR pl. 35) is attested only by F. Vacca, a 16th-c. source (Mem. 5: “… una gran cloaca, quale smaltiva le acque, che camminavano verso il Tevere”, as quoted in Lanciani 282); Ciancio Rossetto holds that the drain Vacca observed was not ancient (LTUR 273, though silent as to why). Thus the segment beneath the Circus remains unattested; its course is often reconstructed in a straight line down the center of the track, but if the *Cloaca Maxima is a valid parallel, this course would be too rectilinear, as Rome’s monumental drain retained every twist of the original riverbed, rather than regularizing its course (Lanciani 280-82). In the Augustan period the Circus’ euripus (water channel) flowed along the edge of the stands and almost certainly utilized the cloaca as a drain, and perhaps even as a source of fresh water (contra, Cressedi 286). The best preserved segment of the “Cloaca Circi Maximi” lies next to S. Maria in Cosmedin. Partially explored in the late 19th c. (Lanciani 281-82, pl. 15, fig. 1; id., FUR pl. 28; Cressedi 257 fig. 3, nos. 8, 11), the remains suggest that the “Cloaca Circi Maximi” was engineered at a scale similar to the Cloaca Maxima (W. c. 2 m, H. c. 7 m; Lanciani 282) prior to the reorganization and raising of the Forum Bovarium in the late 3rd to early 2nd c. B.C. (Coarelli). The discharge of the “Cloaca Circi Maximi” is preserved in the 19th-c. Tiber embankments just S of the mouth of the Cloaca Maxima (Cressedi 262, fig. 6). Thus, the course of the drain is sufficiently understood to map it from the Tiber through the Forum Bovarium (Cressedi 257, fig. 2), but its path through the Circus is too hypothetical to render. As the drain’s ancient name, if indeed it had one, is lost, the modern label “Cloaca Circi Maximi” has been employed here.