Don is a geologist with more than 50 years experience in the discovery, mining and management of mineral resource projects in Australia and overseas. In the mid-2000s he expanded his interests into the fields of Aerial Archaeology, Geoarchaeology, Palaeolandscape, and Ancient History, with a particular focus on Jordan. Participation in ground and airborne (APAAME) surveys in Jordan led to the initiation of the Jarash Water Project (JWP) in 2012, a project researching the ancient water management system to the Greco-Roman Decapolis city of Gerasa (modern Jarash) under his direction. JWP publications include studies on the water management system, landscape history, occupational history, Christian churches, and the archaeological contributions of early 19^th century visitors.

His interests recently expanded into Saudi Arabia where he is involved in the AAKSAU and AAKSAK aerial survey projects and brings his geological experience to bear on studies of the mining heritage and landscape history.

Funding overview

Don Boyer. ‘Jarash Water Project, 2015 Field Season’. Rodney R. T. Prider Scholarship.

Don Boyer. ‘Jarash Water Project, 2016 Field Season’. Rodney R. T. Prider Scholarship.

Don Boyer. Jarash Water Project. ‘Dating of spring sources and related water supply installations to the Roman city of Gerasa (Jarash), Jordan to constrain the chronology of the network's construction and use. (Project N10082). Grant from the Centre for Accelerator Science at ANSTO through the Australian National Collaborative Research Infrastructure Strategy (NCRIS).

Research - Jarash Water Project

Overview

Gerasa (modern Jarash in northern Jordan) was one of the cities of the Decapolis. It grew from relatively humble beginnings in the 2nd century BC to become a prosperous city in the Roman-Byzantine period. Major phases of public building took place in the early Roman period and included temples, theatres, baths, a hippodrome and water monuments that today form the ruins of one of the best-preserved cities in the Roman Empire.

The Jarash Water Project (JWP) was established in 2012 to investigate all aspects of the water management system to the city and its immediate hinterland. The interdisciplinary, contextual approach combines the evaluation of evidence from new ground surveys and a critical examination of evidence in the published corpus with new interdisciplinary studies that provide geoarchaeological and historical contexts. Research to date has focused on the period prior to AD 750, and the results are to be published in a forthcoming monograph. The source, transport and distribution components of the water management system are systematically described, some in detail and many for the first time. The comprehensive study of natural springs highlights the concentration of strong springs in the Jarash valley and the impact this had on settlement patterns and the distribution of irrigation networks. Aqueduct-fed storages (reservoirs and basins) are complemented by runoff storages (cisterns) in both rural and urban contexts, but wells are rare. The city is naturally divided into two parts by the Wadi Jarash. Water on the eastern side city was largely sourced from strong local springs, whereas the western side relied on extramural networks of open channel aqueducts supplied from karstic springs within 3.5 km of the city. Two groups of aqueducts—the north-west network and the northern network—brought water to the western side of the city, but the evidence points to the fountains and most baths being supplied from the north-west network only. The contribution of the northern network to central city consumers is unknown, and this network may only have supplied irrigation water until the Byzantine period, thus contradicting the widely held belief that Birketein, 1.5 km to the north, was the city’s main water source. Radiocarbon dating shows that the earliest aqueduct to the city was in use by the first century AD. The combination of terrain and proximity of the springs resulted in steep aqueduct gradients.

The complex urban distribution network relied on gravity. The fragmentary evidence suggests that open channel conduits delivered water to various castella divisoria, although few are preserved. Baths and fountains were key users: There is no evidence of private connections to aqueducts, and industrial use is largely unquantifiable. Comprehensive spring-fed aqueduct networks irrigated large parts of the Jarash and lower Tannur valleys. The Roman water management system underpinned the growth of the city and the development of its rural hinterland, and it continued to operate into the Early Islamic period.

In the context of the Decapolis, the number, strength and proximity of springs in the study area are unusual, as are the steep aqueduct gradients and the small number of intramural cisterns. The study presents the first interpretation of the urban water distribution network in various periods. The aqueduct network was prone to damage from earthquakes and landslides, and these factors, together with climate change, contributed to the stress on the distribution system reflected in changes to the network in the Byzantine period. None of the components of the system is unique; rather, the system planners preferred to stick with simple installation types. Unusually steep aqueduct gradients and elevation differences within the city required careful management, but it is not clear how this was achieved. The general adequacy of the available spring-fed supplies in the study area can be inferred from the notable lack of any provision for long-term storage. Variations in annual rainfall and the known seasonal variation in spring flows, however, means that it was probably not possible to maintain continuous offtake year-round in the city without the assistance of storage installations, as was the case in many Roman cities in North Africa. Overall, the results present a picture of a water management system that was comprehensively planned and regulated in the Roman-Byzantine period. It was built with practicality and economy in mind and may have had its beginnings in the pre-Roman period.

The next phase of research will extend the study period into the modern era.

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