Fifteen pieces of the elm piping were discovered during the excavation work at George Square, where a state-of-the-art underground heating system is being built by the University of Edinburgh for its new student centre.
The wooden pipes were part of an underground network to supply drinking water which was built in 1756. It ran from the Comiston area of the Capital to the Royal Mile.
Archaeologists called to examine the find – used to bring the “sweet water of the country to the centre” – describe them as being in “very good” condition.
The pipes were usually made from hollowed out elm tree trunks, with holes bored into them at each end to allow the passage of water.
Lindsay Dunbar, Fieldwork Project Manager for AOC Archaeology Group which carried out the excavation, said the pipe fixings of metal bands and lead fittings were “very typical” in wooden pipes used across the UK in the 18th century.
She said: “To uncover these water pipes preserved in situ beneath the cobbles was just incredible. Whilst the use of such wooden pipes is well-documented and preserved examples exist within museums and collections, to find the pipes in situ is much rarer.”
Lindsay added the pipes were “surprisingly well preserved”, offering a unique insight into the design of the network more than 250 years ago.
She said: “These are the first examples we have ever excavated in more than 25 years as a commercial field unit.”
“The level of preservation was very good and allowed important details relating to fittings, construction, size, joining techniques to be recorded prior to their removal.”
In 1621, an act of parliament gave the go-ahead for the town council to construct a pipe line to carry water the three miles from Comiston Springs to the city centre, but almost 50 years of bitter disputes over a proposed ‘water tax’ meant it took nearly half a century for the project to start.
A delay of a further four years for the work to be carried out followed and even when the network was up and running, only the most affluent areas of the Capital would have had access to the supply.
The general public would still have had to make use of “water stands” in the town centre, carrying buckets of water by hand.
Eventually, a network of wooden pipes was used to channel spring water from sources at Liberton and Bonaly. Later the wood – prone, naturally, to rotting – was replaced with cast iron ones.
Although similar pipes have been found before across the Edinburgh’s Old and New Towns, this is the first instance of a section being archaeologically excavated in recent times. The City of Edinburgh Council’s museums have several examples of these pipes within their collections including examples on display at the Museum of Edinburgh.
Bill Elliot, National Stakeholder Manager at Scottish Water said: “This is an amazing find for our customers in Scotland’s capital who have the opportunity to see first-hand how water was distributed in years gone by.
“These pipes made up the first dedicated water supply in Edinburgh, and when the pipes were brought into use the town council described how they would ‘bring the sweet waters of the country to the centre’.
“Records held by Scottish Water show before the wooden water pipes were laid residents could go many weeks without fresh drinking water.”
Councillor Donald Wilson, Culture and Communities Convener, City of Edinburgh Council, said: “This is quite a significant discovery and the first time archaeologists have unearthed the city’s original plumbing system for a long time.”
“Similar pipes were discovered in 1894 in West Register Street. Made from hollowed out elm they date from the 17th to 18th centuries and were used to supply water to Edinburgh’s Old Town from springs like those out at Comiston.
“In fact, we have two sections of it on display at our free-to-visit Museum of Edinburgh in the Canongate.”