Aqua Marcia

Nevertheless flow rates were still too low to meet growing demand, so the Senate decided to build a new aqueduct, longer and more ambitious than the previous ones, bringing water to the Capitoline Hill, a technical feat for the time due to its height.

It was largely paid for by spoils from the recent Roman conquests of Corinth in 146 BC and the destruction of Carthage at the end of the Third Punic War, in the same year.

[7] Its extension to the Capitoline Hill caused controversy because traditionalists were concerned about a passage in the Sibylline Books warning against bringing water there[8] and in 140 BC the case was brought before the Senate who rejected it.

The ancient source for the aqueduct was near where small lakes were formed by two springs in the Anio valley between the modern towns of Arsoli and Marano Equo.

The route was mainly underground for the first 80 km after which it emerged on large monumental arches to ensure there was a good water head (pressure) for distribution in Rome.

It continued towards Tivoli and then, bypassing the Tiburtini Mountains and after the current municipality of Gericomio it crossed the Gallicano area and the via Praenestina in Lazio with alternating bridges (of which many are visible) and underground sections.

After the Capannelle area it headed directly to Rome and surfaced at the seventh mile of the Via Latina, where there was a limaria pool (settling basin).

From here a stretch of about 9 km arches flanked the Via Latina and reached Rome in the locality ad spem veterem, near Porta Maggiore, where other aqueducts met.

The Ponte Lupo[11] is considered one of the most famous and interesting bridges of the Roman aqueducts;[12] to allow the Aqua Marcia to cross the deep Aniene Valley on its way to Rome it had to be more than 30 m high and over 80 m long.

The Ponte della Bullica crosses the Collafri stream with a single round arch in radial tuff ashlars with a span of 5.8 m and is 5.5 m high, 3.3 m wide and 10.6 m long.