Roman water infrastructure in post-Roman Britain. Part 2: Post-Roman survival

Part 1 listed some examples of sophisticated Roman water engineering in British towns and fortresses. How much of this infrastructure survived into the post-Roman period and for how long?

There is evidence that at least some water supply systems were maintained very late in, or after, the Roman period. For example, a timber-lined water trench was constructed in York some time in the fourth century AD (Ottaway 2004), and in St Albans (Roman Verulamium) a new water main had been laid later than the fourth-century Roman levels, probably some time in the fifth century (I can’t find a link online and haven’t got the book to hand, but this Amazon review mentions it). The Roman sewer system excavated at Church Street, York, is considered to have been used until the late 4th or early 5th century, on the basis of pottery finds (Buckland 1976).

Even when maintenance had ceased, some of the infrastructure may well have remained operational for a considerable time. Complex pumping devices such as the London bucket-chain system (see part 1) would probably have broken down fairly quickly without regular maintenance and repair. Wells, however, could have been used until they became contaminated or blocked; it seems logical to me that common sense prompts people to continue using existing infrastructure as long as it still works and is still useful. There is a suggestion that the seventh-century monastery founded by St Hild at Whitby on the Yorkshire coast may have utilised the well from a Roman signal station on the same site (Mundahl-Harris 1997), though no evidence is quoted for or against. (No definite trace of a Roman signal station on Whitby cliffs has been found, apart from a few Roman coins from an excavation in the 1930s, but as the two known signal stations either side are out of sight of each other, I think it very likely that there was one in between, and it may well have been at Whitby).

Sophisticated aqueducts such as those serving Lugdunum in Gaul (modern Lyon; see part 1) would fail as soon as one of the closed siphons leaked or an arch collapsed. There is less to go wrong with a simple gravity-fed aqueduct consisting of a pipe in a trench laid along natural contours. Such systems could have functioned for a long period until they fractured, collapsed or silted up. Wooden water pipes (bored-out logs, like the ones discovered at Colchester) supplying spring water to Vindolanda fort on Hadrian’s Wall were still working almost 2000 years after they were laid, efficiently enough to flood the archaeological excavation that discovered them.

One item of documentary evidence can be added to the archaeological evidence. In his Life of St Cuthbert, Bede describes a visit by St Cuthbert and the then queen of Northumbria to Lugubalia (modern Carlisle) in 685 AD, where the local citizens showed them the town walls and ‘a remarkable fountain, formerly built by the Romans’ (Chapter 27).

This suggests to me that Carlisle probably had a gravity-fed aqueduct that was still working and still serving a street fountain (or possibly a fountain in what had once been a private house or a baths complex), and that the local inhabitants knew about it and were proud of it. Perhaps they still used it.

I think it is also noteworthy that Bede and/or his informant knew who built the fountain, which suggests that some knowledge of Britain’s Roman heritage was still extant when Bede was writing in the 730s. It is sometimes claimed, usually on the basis of the poem The Ruin (from the 10th-century Exeter Book manuscript), that the early English (‘Anglo-Saxons’) were ignorant of the Roman past and superstitiously believed that Roman buildings had been made by giants. Very possibly some people did; but Bede’s mention of the fountain at Carlisle indicates that this was not always the case. It can be argued that knowledge of the Romans and their architecture was reintroduced from Continental records by St Augustine’s missionaries from the Roman Catholic church and that this was the source of Bede’s knowledge. However, it should be noted that Bede did not have accurate information on the building of the Antonine Wall and Hadrian’s Wall; in his Ecclesiastical History he follows Gildas’ erroneous assertion that the Britons built the Antonine Wall and that the Romans then built Hadrian’s Wall and left immediately, leaving the Britons to man it (Book I Ch. 12). It seems unlikely that records reintroduced from the Continent by the Roman church would have known the origin of a fountain in Carlisle but not known who built the two major defensive structures in northern Britain. It seems to me that some continuity of local tradition is a simpler explanation than loss and reintroduction of information.

I interpret the information as follows: Towns and military sites in Roman Britain were provided with engineered water supply systems, which were maintained on at least some sites up to or after the end of the Roman period. Some of these systems, gravity-fed underground aqueducts in particular, were sufficiently simple and robust that they could have continued to function for a considerable time even after maintenance had ceased. The underground water pipes at Vindolanda were still working after nearly 2000 years. Bede’s mention of the fountain in Carlisle is consistent with a working gravity-fed aqueduct there in 685 AD. This was probably unusual, as Bede thought it was worthy of mention and the locals thought it was worth showing off to visiting dignitaries, but it was not necessarily unique; the Vindolanda water pipes show that much longer survival was possible. The origin of the fountain was known to Bede and/or Bede’s informant, although there is no indication as to whether anyone still understood how it worked. It is possible, and may even be probable, that similar systems survived in other Roman towns and forts, and that they continued to be used as a source of fresh water by populations living on those sites for a considerable period, perhaps centuries. (How large those populations were, and how long they stayed, is a separate question). It’s often assumed that a major reason for people to continue living in or near Roman towns and forts was the presence of surviving defensive fortifications. I wonder if the presence of a surviving water supply may also have played some role?

What do you think?


References:
Bede, Life of St Cuthbert. Translation available online.
Bede, Ecclesiastical History of the English People. Translated by Leo Sherley-Price, Penguin Classics, 1968.
Buckland PC, The environmental evidence from the Church Street Roman sewer system. York Archaeological Trust, 1976.
Mundahl-Harris S, St Hilda and her times. Caedmon Press, Whitby, 1997.
Ottaway P. Roman York. Tempus Publishing, 2004.