Heavy metals from urban runoff preserved in sedimentary deposits record long-term economic and industrial development via the expansion and contraction of a city's infrastructure. Lead concentrations and isotopic compositions measured in the sediments of the harbor of Ostia-Rome's first harbor-show that lead pipes used in the water supply networks of Rome and Ostia were the only source of radiogenic Pb, which, in geologically young central Italy, is the hallmark of urban pollution. High-resolution geochemical, isotopic, and C analyses of a sedimentary core from Ostia harbor have allowed us to date the commissioning of Rome's lead pipe water distribution system to around the second century BC, considerably later than Rome's first aqueduct built in the late fourth century BC. Even more significantly, the isotopic record of Pb pollution proves to be an unparalleled proxy for tracking the urban development of ancient Rome over more than a millennium, providing a semiquantitative record of the water system's initial expansion, its later neglect, probably during the civil wars of the first century BC, and its peaking in extent during the relative stability of the early high Imperial period. This core record fills the gap in the system's history before the appearance of more detailed literary and inscriptional evidence from the late first century BC onward. It also preserves evidence of the changes in the dynamics of the Tiber River that accompanied the construction of Rome's artificial port,, during the first and second centuries AD.

No abstract

This paper evaluates conveyance and flow characteristics for the Anio Novus, the aqueduct bringing water from the greatest distance to ancient Rome. Travertine accumulations, deposited from water on floor and walls, were used to reconstruct the flow rate and associated spatial and temporal variations. Hydraulic quantities (e.g., flow depth and velocity) markedly varied over the course of the aqueduct, implying that constraints such as topography and construction techniques were combined with hydraulic considerations to determine the aqueduct layout. Design practices differed along the aqueduct and channel size design was not based exclusively on anticipated carrying capacity, tending towards larger‐than‐necessary design based on experience.

The influence of a sophisticated water distribution system on urban development in Roman times is tested against the impact of Vesuvius volcanic activity, in particular the great eruption of AD 79, on all of the ancient cities of the Bay of Naples (Neapolis). Written accounts on urbanization outside of Rome are scarce and the archaeological record sketchy, especially during the tumultuous fifth and sixth centuries AD when Neapolis became the dominant city in the region. Here we show that isotopic ratios of lead measured on a well-dated sedimentary sequence from Neapolis' harbor covering the first six centuries CE have recorded how the AD 79 eruption was followed by a complete overhaul of Neapolis' water supply network. The Pb isotopic signatures of the sediments further reveal that the previously steady growth of Neapolis' water distribution system ceased during the collapse of the fifth century AD, although vital repairs to this critical infrastructure were still carried out in the aftermath of invasions and volcanic eruptions.AD 79 Somma-Vesuvius eruption | Pb isotopes | harbor geoarchaeology | Neapolis | paleo-pollution U rban centers have always been critically dependent on a stable water supply, and ancient cities relying on masonry aqueducts were particularly vulnerable to the disruption of their water distribution system by earthquakes and volcanic eruptions (1). The archaeological record of the major eruption of Vesuvius in AD 79 and its effect on the water supply of Naples, then known as Neapolis, and its neighboring cities illustrates well how efficiently the Roman world was able to mitigate the effects of major disasters on the daily life of its population. Neapolis: Water Supply and VolcanismNeapolis and the surrounding region were supplied with water from the Aqua Augusta or Serino aqueduct, built during the reign of Augustus between 27 BC and AD 10 (2, 3). The Augusta was a regional network supplying eight or nine cities, as well as numerous villas, through multiple branches (Fig. 1A): Nola, possibly Pompeii, Acerrae, Atella, Neapolis, Puteoli, Cumae, Baiae, and Misenum (2, 4). The total length of the aqueduct, including its branches, was ∼140 km. The construction of this monumental hydraulic network helped meet a need to secure the water supply for the strategic region of Campania during a critical period: the establishment of the Principate (2). The aim of the Augusta was to provide water to naval harbors (first Portus Iulius and later Misenum) and the commercial harbor of Puteoli, one of the busiest centers of trade in the Roman Empire (5), as well as to cities, coloniae, and villas of influential individuals. At an unknown time between the fifth century BC and the Middle Ages, the Bolla aqueduct (Fig. 1A) was constructed to bring additional water to Neapolis (3).One of the challenges in maintaining the Augusta and, with it, the integrity of the water supply of the heavily settled area around Neapolis, was counteracting the slow movements of the ground associated with the activity of volcanic sy...

The reconstruction of Pompeii's water-supply system is currently the focus of much debate. This debate is fueled by complicated and growing archaeological evidence for the water system within the town as well as three different proposed configura tions of Pompeii's aqueduct. The new synthesis of archaeological evidence presented here reveals three successive phases of piped distribution. The first, Augustan phase was altered considerably in a second phase to keep it operating, albeit with reduced supply, in the town's last decades. At the time of the eruption of Somma-Vesuvius in 79 C.E., a wholly new, third phase was under construction. A new interpretation of the archaeological remains around Ponte Tirone shows that the water that supplied Pompeii's distribution system came from either the Aqua Augusta or Somma-Vesuvius, but probably not from the Abella aqueduct. In addition, there is evidence in Ponte Tirone for a minimum ground uplift of approximately 30 cm on the flanks of the volcano prior to the eruption and greater deflation afterward. This uplift reduced and then stopped water supply to towns around the Bay of Naples, but whether it affected Pompeii remains unclear. This analysis further develops a new method of reconstructing past vertical ground movements via their impact on shallow-gradient, gravity-powered water systems.* in t r o d u c t io n : t h e c u r r e n t d e b a t e o v e r t h e s o u r c e a n d e n d o f p o m p e ii's w a t e rd is t r ib u t io n sy st e mTwo lo n g -ru n n in g deb ates reg a rd in g P o m p eii's a q u e d u c t a n d lead-pipe distribution system co n c ern (1) th e w ater system 's source, a n d (2) its e n d . In particular, scholars disagree a b o u t th e source an d d ate o f th e first aqu ed u ctsup p lied w ater d istrib u ted th ro u g h o u t th e city, as well as th e status o f th e w ater system in th e last two decad es betw een th e 62 -6 4 C.E. ea rth q u a k e s* 1 a n d th e 79 C.E. eru p tio n o f Somma-Vesuvius.2 T h e th re e d iffe ren t sources p ro p o sed fo r th e system are discussed below. M ost scholars have a rg u e d fo r an A ugustan d ate fo r th e aq u ed u ct-su p p lied system, b u t som e scholars have posited th a t S am nite o r Sullan colonial systems p re c e d e d th e A ugustan o n e .3