RIVERBED, BANKS AND BEYOND: AN EXAMINATION OF ROMAN INFRASTRUCTURE AND INTERVENTIONS IN RESPONSE TO HYDROLOGICAL RISK IN THE PO–VENETIAN PLAIN

Abstract

Water poses a particular challenge to the cities and settlements of the Po–Venetian plain. The region has some of the highest levels of precipitation in Italy and is criss-crossed by dozens of rivers, including the Po, Adige and Tagliamento. Throughout history, there was considerable hydrological risk to the well-being of riparian communities from hazards such as flooding and lateral channel movement, yet local residents did not sit idly by. This article synthesizes the available evidence for Roman responses to hydrological risk in the Po–Venetian plain from the first century BC to the sixth century AD, examining their workings and the hazards they sought to counteract, integrating them into wider discussions on risk in the Roman world. The responses are divided into the categories of defensive works (embankments and dykes) and channel interventions (channel rectification, channel diversion and dredging). While the effectiveness of these methods is questioned, in particular their potential to cause unintended changes to the watercourse, the decision by riparian communities to undertake them suggests a degree of local success. Nevertheless, an examination of the archaeological and palaeoclimatic evidence suggests a discrepancy between peak intervention and peak risk, implying increasing vulnerability and risk acceptance amongst riparian communities during late antiquity.