Discover How Romans Drain the Fens & Somerset Levels?

There is no doubt that the Romans were early innovators, responsible for some impressive feats of engineering and some formidable defensive structures.

But how did they leave their mark on the natural landscape of Great Britain?

And how do the Fens and the Somerset Marshes tell the story of Roman settlement?

What are the Somerset Levels?
The Romans and the Somerset Levels
What are the Fens?
The Romans and the Fens Causeway
Who Drained the Fens?

What are the Somerset Levels?

The Somerset Levels make up a large piece of flat, low-lying wetland/coastal plain in Somerset, England.

They spread across 160,000 acres to Clevedon, Ilchester, Bridgwater Bay and the Bristol Channel and sit just a few metres above sea level.

For centuries, because of its low-lying position, the area was prone to flooding. These floods were often difficult to predict, both in frequency and severity, but made for incredibly fertile soil.

This meant that the land was desirable, for what it could offer for farming and crop growth, yet incredibly inconvenient to settle on.

Furthermore, settlements on the high ground could become well-defended in the event of a flood but one would need a sturdy boat if he did not wish to become trapped or besieged on his own land.

Ultimately, the benefits outweighed the negatives and a number of settlements, on the naturally higher ground, were established during the Neolithic period.

To make these settlements navigable a number of timber trackways were constructed.

Neolithic sweet track — Replica of the Sweet Track

The most famous of these was discovered in 1970 by a man named Ray Sweet and named the Sweet Track. This track ran between Westhay and Shapwick, for about 1.2 miles (2km).

Once the Levels were made somewhat navigable, settlement in the area increased.

During the Iron Age, a particularly impressive settlement was constructed known as Glastonbury Lake Village.

It was constructed on an artificial mound and was large enough to hold 200 people but was later abandoned in 50AD, most likely because of the rising water levels.

The Romans and The Somerset Levels

Settlement continued until the Romans were drawn to the area for, amongst many reasons, the opportunity to extract salt.

As trade grew, settlement expanded and a number of villages appeared on the Polden Hills as well as possibly at Draycott, the Cheddar Moors and near Highbridge.

One of the most impressive pieces of evidence of Roman occupation in the area came from an excavation of a settlement in Shapwick.

Here archaeologists stumbled upon the second-largest hoard of Roman coins found in England at the time (about 9,238 in total) in the corner of what was once a villa.

The Shapwick Hoard on display at the Museum of Somerset. Credit: Rodw

The hoard was dated as early as 31-30BC and it contained particularly rare coins that had not been found in the country prior as well as the largest number of silver denarii discovered in the country.

Read More: Meare Heath Trackway: A Bronze Age Structure

Whilst they occupied this land the Romans created artificial flood defences in order to control the tides from the Severn Estuary.

These defences were composed of ditches which were dug to create a network of channels which would drain the marshland.

Unfortunately, their efforts were not widespread nor effective enough to fight off the tides for long and the Romans lost to the rising water which eventually beat their efforts to drain the marshes.

What are the Fens?

The Fens, much like the Somerset Levels, are a marshland located in the east of England.

They cover 1,500 square miles and cross Lincolnshire, Cambridgeshire and Norfolk, running all the way up to the Wash.

Again, much like the Levels, the land in the Fens is flat, low-lying and prone to flooding but provides a fertile environment not only for farming but for a great number of species too.

a map of the Fens — The Kingdom of East Anglia during the early Anglo-Saxon period, showing the approximate coastline and the Fens at the time

Because of this, the area has been nominated a ‘National Character Area.’

Before they were drained, the Fens were liable to periodic flooding, particularly during winter when there was lots of rain and water running down from higher land.

Sometimes the flooding was so bad that areas remained flooded permanently and lakes were created.

The Romans and The Fen Causeway

Just as early humans had constructed the Sweet Track in Somerset, the Romans constructed what has become known as the Fen Causeway in the East.

This road linked East Anglia with what would later become the rest of England via the Fens and ran between Denver and Peterborough and also linked Cambridge and Ely.

The Romans constructed this causeway by driving some 60,000 sharp-tipped wooden posts into the ground – some of which have been uncovered by archaeologists.

It is said to have been about 1 km (0.6 miles) long and in some places up to 18 metres wide. It was raised above the marshy Fens and had a centre platform.

Archaeologists believe that it mainly weaved between the most inaccessible parts of the Fens aside from a few smaller roads which were designed to provide access to out-of-the-way regions that produced vital products like beef, salt and leather.

The causeway linked the ‘Fen Islands’ or ‘Townlands’ which were settlements constructed, as in Somerset, on higher land to avoid the flooding.

Some of these settlements provided homes for people whilst others were occupied as farms.

Who Drained the Fens?

It is generally thought there were at least some efforts to drain the Fens during the Roman period.

Archaeologists believe that Car Dyke, an 80-mile-long (128km) water channel that runs all the way from Cambridge to Lincoln, crossing through Peterborough, was constructed by the Romans as a way to do so around AD 125 during the reign of Emperor Hadrian.

The Counter Drain — The Fens, also known as the Fenland, is a naturally marshy region in eastern England. Most of the fens were drained several centuries ago, resulting in a flat, damp, low-lying agricultural region. Credit: Bob Harvey

Unfortunately, there are no records which explain the reasons for the construction of this mighty channel.

Despite this, archaeologists have come up with theories.

Some argue that it was primarily a drainage system for the Fens, others argue that it was meant to be a canal to provide transportation and others argue it was meant to be a defensible boundary, like Hadrian’s Wall in the north.

Car Dyke

The origins of the theory that Car Dyke was a canal was a man named William Stukeley (1687-1765) who, in the 18th century, argued that it was constructed to provide the Roman armies in the north with food and supplies from Cambridgeshire and Lincolnshire.

He acknowledged that it was also built as a drainage system but this, he argued, was only a secondary function.

However, in 1989 when the Trust for Lincolnshire Archeology excavated a section of the Dyke in Baston, Lincolnshire, they uncovered evidence that made them lean away from Stukeley’s argument.

roman — Car Dyke mosaic sign near Martin, Lincolnshire, showing a surveyor using a groma. Credit: Richard Croft

Their dig showed that the Dyke had originally been 13 metres wide, 3.6 metres deep and full of fast-flowing water.

This implied that it had been constructed primarily as a drainage system but may also have been used for transportation, as a secondary use.

Roman Boats

They cited as further evidence for this argument the fact that the construction of large sections of Car Dyke coincided with the visit of the Roman Emperor, Hadrian, to Britain in 120 AD.

Read More: The Forgotten Roman Roads

During this period, Hadrian had been vocal about his desire to settle in the Fens.

This is not to say, however, that the Dyke served just one purpose alone, or for its entire length.

Further south in Waterbeach in 1990 excavations uncovered the remains of Roman boats, cargo pottery and coal from the Midlands.

Wicken Fen is divided by a man-made watercourse called “Wicken Lode”. The area north of Wicken Lode, together with a smaller area known as Wicken Poors’ Fen and St. Edmunds Fen, forms the classic old, undrained fen.

These findings imply that the Dyke, at least here, was also used for transportation.

Regardless of its construction, it is certainly an impressive piece of Roman engineering.

Alongside Car Dyke, the Romans constructed a number of other waterways which had the combined role of draining the Fens and providing transport systems through the country.

Whilst these, again, were impressive feats of early engineering, they did not completely drain the fens.

A large-scale attempt to drain them was made much later in the 1630s when wealthy landowners were motivated by the fertile soil that could be used in summer cultivation.

Whilst the Romans did not achieve large-scale drainage of the Fens, or the Somerset Marshes, they certainly made substantial efforts to do so.

Whilst these efforts were small in comparison to those made later, they left impressive marks on the country’s landscape that can still be seen today and stand as a testament to Roman ingenuity and engineering.