The sandy subsoil of Ostia is the seat of a rich and rather shallow aquifer, which in antiquity was exploited by digging wells. The “well-heads” of many of them are still visible today. These are modest and often hidden features, but with a great meaning, since they mark the only sources of drinking water before the construction of the aqueduct at the end of the 1st century AD.
The technique of drilling a well is explained by Vitruvius: “If there be no springs from which water can be obtained, it is necessary to dig wells, on which every care is to be bestowed (..). When (..) we come to water, the well must be lined with a wall, but in such a manner as not to shut out the springs.”
The almost 60 wells known in Ostia are collected in “La civiltà dell’acqua in Ostia Antica” by Ricciardi M. A., Scrinari Valnea S. M., 1996-7.
In the Republican period, from the III century b.C. on, many wells were dug in Ostia. We find them within the walls of the Castrum and concentrated along the Decumanus Maximus. Probably they started as public services and were later incorporated in private buildings.
The well of the House of the Mosaic Niche is a highly visible example along the Cardo Maximus, with a simple marble well head and the base sculptured with leaves. In the Sacred Area of the Republican Temples, located along the right side of the Via della Foce, an inscription attests to the cult of the Acqua Salvia. The presence here of a spring, or better a natural water pool, may be presumed. The latter, eventually accompanied by gas emanation, is a well-known phenomenon in other stretches of the “old” dunes of the coastal plain of Rome.
Tonnie Huijzendveld (Arnoldus)