POMPEII & NAPLES BAY: ANCIENT ROMAN WATER SUPPLIES & WATER USE REPORT OF FIELD OBSERVATIONS ‐ SEPTEMBER 2016 Wayne Lorenz i PREFACE The Wright Paleohydrological Institute (WPI) has been researching the Aqua Augusta, the ancient Roman aqueduct that served the Naples Bay region of Italy, including the ancient City of Pompeii, and water use in the city. A few facts regarding the aqueduct and related water systems provide some background to this report. First, ancient Pompeii can justifiably be identified as the most famous archaeological site in the world (Berry, 2007), likely due to its preservation under about 3 to 12 meters (10 to 40 feet) of volcanic ash after the eruption of Mount Vesuvius in A.D. 79. It was here that the modern study of “archaeology” began when the city started to be unearthed over 250 years ago. It is interesting to note that Pompeii is about 75 percent excavated and has revealed many unique details of Roman culture and technology. The archaeological areas of Pompeii, (as well as Herculaneum and Torre Annunziata) were listed as UNESCO World Heritage sites in 1997. The historic center of Naples is also a UNESCO site. The engineering and construction of the Aqua Augusta (also known as the Serino Aqueduct) provided a fresh water supply to communities and fostered economic development in the Naples Bay region during the first century A.D. The aqueduct supplied Pompeii and at least 9 other distinct communities, plus multiple villas, in the Bay of Naples through a system of ten side branches. This seems to have been the most complex single aqueduct ever built by the Romans (Keenan-Jones, 2010). As a comparison, the City of Rome was supplied by 11 separate aqueducts. The aqueduct was built under the Emperor Augustus (between 33 and 12 B.C.), it crossed hilly terrain with channel gradients that varied, impacting hydraulics. A minimum gradient of the channel in one segment was 0.04 percent. Nevertheless, a flow of at least 1,000 liters per second (15,850 gallons per minute or 23 million gallons per day) was possible. A great portion of the Aqua Augusta was engineered to be tunneled under the hilly terrain, with some sections as much as 65 to 97 meters (210 to 320 feet) below the existing grade. One of the goals of WPI is to map ii the alignment of the aqueduct, some 100 kilometers (approximately 60 miles) from the Acquaro – Pelosi Springs to the presumed end of the aqueduct at the storage reservoir called the Piscina Mirabilis. Pompeii had a population of between 8,000 and 12,000 (Storey, 1997) when Mt. Vesuvius erupted. Several researchers have made attempts to estimate the flow of water from the Aqua Augusta that was directed to Pompeii for domestic use in the city. H. Eschebach (1993) calculated the total water supply to the city to 75 liters per second (1,200 gallons per minute or 1.7 million gallons per day) based on the water inlet area of the aqueduct, 0.25 by 0.3 meters (0.8 by 1 foot), and a water velocity of 1 meter per second (3.3 feet per second). Ohlig (2001) discussed the water demands of the city and based his estimation on a water consumption of 200 to 400 liters per person per day (50 to 100 gallons per capita per day) for a population of about 8,000 people, giving a calculated total water quantity of 20 to 40 liters per second (320 gallons per minute to 634 gallons per minute, or up to 0.9 million gallons per day). Based on review of the hydraulic engineering evidence, the flow to Pompeii from the aqueduct was about 40 liters per second (634 gallons per minute or 0.9 million gallons per day). The water was distributed in the city through a water distribution system that included a hydraulic flow splitter box and gates, lead piping, water towers, and street fountains. Water from the aqueduct was used for public baths, commercial shops, irrigation of private gardens, indoor water features, and in-house domestic applications. iii TABLE OF CONTENTS Page 1.0 INTRODUCTION ............................................................................................................... 1 2.0 HOUSES IN POMPEII ...................................................................................................... 2 2.1 Casa dei Vettii (September 29) ........................................................................................... 3 2.2 Casa dell’ Efebo (September 24) ........................................................................................ 4 2.3 Casa di Orfeo (September 29) ............................................................................................ 7 2.4 Casa di Trebius Valens (September 26) ............................................................................. 8 3.0 PISCINA MIRABILIS ........................................................................................................ 9 4.0 ARCADES ...................................................................................................................... 11 4.1 Mura d’Arce (September 26) ............................................................................................. 11 4.2 Pomigliano D’Arco (September 29) .................................................................................. 12 5.0 SANITA’ NAPLES (SEPTEMBER 24) ........................................................................... 14 6.0 SARNO SPRINGS MUSEUM VISIT, AND IDENTIFICATION OF ANOTHER ALIGNMENT LOCATION (SEPTEMBER 26) ................................................................ 15 7.0 VOLTURARA IRPINA – DRAGON’S MOUTH & SPRINGS (SEPTEMBER 28) ........... 18 8.0 CISTERNS IN BACOLI (SEPTEMBER 25 AND 27) ...................................................... 20 8.1 Grottoni Cistern ................................................................................................................. 21 8.2 Villa Angri Sani Cistern ..................................................................................................... 21 8.3 Grotto Dragonara Cistern .................................................................................................. 22 8.4 Scalandrone Tunnel .......................................................................................................... 22 9.0 HERCULANEUM (SEPTEMBER 28) ............................................................................. 23 10.0 REFERENCES ................................................................................................................ 25 11.0 ACKNOWLEDGEMENTS ............................................................................................... 25 12.0 APPENDIX ...................................................................................................................... 26 iv FIGURES Figure 1. WPI team from left to right include Wayne Lorenz (Team Leader), Gary Witt (Hydrogeologist and Photographer) and Peppe Iliano (Local Guide and Liason) ....................................... 1 Figure 2. Peppe Iliano and Prof. Stefani in the Casa dei Vettii. ................................................................... 3 Figure 3. Large lead pipe in the kitchen of the Casa dei Vettii. ................................................................... 4 Figure 4. Evidence of a water vessel attached to the wall. .......................................................................... 4 Figure 5. Private water tower behind a large painting of Mars and Venus as observed from the entrance to the residence from Vicola dell’Efebo. ............................................................................ 5 Figure 6. Plan view of Casa dell’ Efebo showing the configuration of lead pipes used to deliver water throughout the residence. .................................................................................................. 6 Figure 7. Nymphaeum and water basin in the garden area of Casa dell’ Efebo. ........................................ 6 Figure 8. Plaster cast of a guard dog found in the Casa di Orfeo. ............................................................... 7 Figure 9. Valve box with two valves in Casa di Orfeo. ................................................................................. 8 Figure 10. Marble valve box with cover adjacent to pedestal and impluvuim. ............................................. 8 Figure 11. Water fountain with remaining pedestal in Casa di Trebius Valens. .......................................... 9 Figure 12. Interior of Piscina Mirabilis near the south east stairway. ........................................................ 10 Figure 13. Mura d’Arce arches and buttresses as viewed from the south. ................................................ 12 Figure 14. Aerial image of the large railroad span that by passes the arcade foundation of the Aqua Augusta. ........................................................................................................................... 13 Figure 15. Remnant of arcade foundation near Pomigliano d’Arco. .......................................................... 13 Figure 16. Archeological excavation along proposed elevated railway section shows a remnant of arcade foundation. ....................................................................................................................... 13 Figure 17. Gary Witt, Meisha Hunter Burkett and Wayne Lorenz meet for espresso in downtown Naples .............................................................................................................................. 14 Figure 18. Model of the Aqua Augusta as discovered beneath several buildings in downtown Naples.