Five wooden wells, one dated to 719 to 396 BC, were found on the route of Southern Water's new pipe from Otterbourne to Southampton. Updated November 2026.

Archaeologists digging ahead of Southern Water’s new pipeline from Otterbourne to Southampton have found five wooden water wells, the oldest of them built in the Early Iron Age. Radiocarbon dating of one well places its construction between 719 and 396 BC (Southern Water).

The wells were uncovered north of Southampton by Archaeology South-East (ASE), part of the UCL Institute of Archaeology, during excavations paid for by Southern Water before it lays the Southampton Link Main, a 19km pipe running from Otterbourne, in the Winchester district, to Southampton. Southern Water has not said exactly where on the route the dig took place.

A spring used for centuries

The wells all tapped the same spring, which the archaeologists say people used as a water source in both the Iron Age and the Roman period. The wet ground around it starved the timber of oxygen, and that is why the wood survived.

Rachael Geoghegan of UCL Archaeology South-East, who led the excavation, said:

“It is rare and exciting to find wooden structures from this time period. The oxygen-starved conditions caused by the wet soil around the spring prevented the wood’s decomposition, preserving the ancient timbers in exquisite detail. We can even see axe marks on some of the timbers.”

Three archaeologists in orange high-visibility clothing and helmets crouch in a waterlogged pit around a section of timber wrapped in plastic
Archaeologists with a wrapped, waterlogged timber in a flooded pit on the site. Photo: supplied by Southern Water, credit UCL Archaeology South-East

Hollow logs and a Roman timber pit

Four of the five are what archaeologists call “hollow log-lined wells”: oak trunks hollowed out and set into pits. The largest is 70 centimetres across. One was held in place by a ring of stakes. Another had been mended while it was still in use, with a wooden shovel blade pushed in to support a broken section.

Pottery found in and around these wells shows people were still drawing water there in the later Roman period.

The fifth well is Roman and was built a different way. Instead of a hollow log, its builders dug a shallow rectangular pit and lined it with timber planks and stakes. Early identification suggests it is mostly oak too, with both large timbers and roundwood stakes, so the wood came from saplings as well as older trees.

A digital model of a hollowed-out oak trunk, dark brown, open at the top, shown against a grey background
A digital model of one of the hollow-log wells. Image: supplied by Southern Water, credit UCL Archaeology South-East

Hannah Street, a waterlogged wood specialist at UCL Archaeology South-East, said:

“It’s a great opportunity to work on a site with such exceptionally well-preserved wood. Working closely with our conservator we carefully lifted the Iron Age hollowed logs in as complete a condition as possible. The Roman well in particular required meticulous excavation and recording to untangle the different phases of its timber construction. Together these wells provide a fascinating window into how technology developed from the Iron Age through to the Roman period, revealing changing approaches to construction and water management.”

What happens to the finds

The work is not finished. ASE is still analysing the finds and the soil samples taken from the wells. Pollen and plant remains preserved in the mud could show what people were doing around the wells, what the surrounding landscape looked like, and when the wells stopped being used.

The archaeologists also hope to date the Roman well more precisely using dendrochronology, which matches the pattern of growth rings in the older timbers to work out when the trees were cut down.

The pipe that found them

Southern Water says it is spending more than £100 million on the Southampton Link Main. It says the pipe will help close a shortfall of about 200 million litres a day that Hampshire faces in a drought.

Phil Maunder, project manager at Southern Water, said:

“This is a terrific find and one that contrasts a two-thousand-year-old water source with a modern water project. There are many exciting aspects to major projects, and this is a great example.

“We’re investing more than £100million in the Southampton Link Main (SLM) project and once operational, the project will play a vital role in keeping Hampshire’s taps and rivers flowing for future generations.”

What it means for you

  • Nothing to visit yet. The timbers have been lifted for study, and Southern Water has not announced any display or open day.
  • Living near the route? The pipeline runs 19km from Otterbourne to Southampton. Southern Water has given no completion date in this announcement.
  • More results to come. Dates for the Roman well and the findings from the soil samples will follow once ASE’s analysis is done.

Source: Southern Water, “Ancient water source found during modern water pipeline excavations”, 6 November 2026.