The Fens

The Fens or Fenlands in eastern England are a naturally marshy region supporting a rich ecology and numerous species. Most of the fens were drained centuries ago, resulting in a flat, dry, low-lying agricultural region supported by a system of drainage channels, man-made rivers, and automated pumping stations. There have been unintended consequences to this reclamation, as the land level has continued to sink and the dykes have been built higher to protect it from flooding.
Fen is the local term for an individual area of marshland or former marshland. It also designates the type of marsh typical of the area, which has neutral or alkaline water and relatively large quantities of dissolved minerals, but few other plant nutrients.
The Fens are a National Character Area, based on their landscape, biodiversity, geodiversity and economic activity.
The Fens lie inland of the Wash, and are an area of nearly in the south east of Lincolnshire, most of Cambridgeshire, and western-most parts of Norfolk and Suffolk.
Most of the Fens lie within a few metres of sea level. As with similar areas in the Netherlands, much of the Fenland originally consisted of fresh- or salt-water wetlands. These have been artificially drained and continue to be protected from floods by drainage banks and pumps. With the support of this drainage system, the Fenland has become a major arable agricultural region for grains and vegetables. The Fens are particularly fertile, containing around half of the grade 1 agricultural land in England.
The Fens have been referred to as the "Holy Land of the English" because of the former monasteries, now churches and cathedrals, of Crowland, Ely, Peterborough, Ramsey and Thorney. Other significant settlements in the Fens include Boston, Downham Market, King’s Lynn, Mildenhall, March, Spalding, and Wisbech.

Background: historical flooding and drainage

The Fens are very low-lying compared with the chalk and limestone uplands that surround them – in most places no more than above sea level. As a result of drainage and the subsequent shrinkage of the peat fens, many parts of the Fens now lie below mean sea level. Although one writer in the 17th century described the Fenland as entirely above sea level, the area now includes the lowest land in the United Kingdom. Holme Fen in Cambridgeshire, is around below sea level. Within the Fens are a few hills, which have historically been called "islands", as they remained dry when the low-lying fens around them were flooded. The largest of the fen-islands was the 23-square-mile Kimmeridge Clay island, on which the cathedral city of Ely was built: its highest point is above mean sea level.
Without artificial drainage and flood protection, the Fens would be liable to periodic flooding, particularly in winter due to the heavy load of water flowing down from the uplands and overflowing the rivers. Some areas of the Fens were once permanently flooded, creating lakes or meres, while others were flooded only during periods of high water. In the pre-modern period, arable farming was limited to the higher areas of the surrounding uplands, the fen islands, and the so-called "Townlands", an arch of silt ground around the Wash, where the towns had their arable fields. Though these lands were lower than the peat fens before the peat shrinkage began, the more stable silt soils were reclaimed by medieval farmers and embanked against any floods coming down from the peat areas or from the sea. The rest of the Fenland was dedicated to pastoral farming, fishing, fowling, and the harvesting of reeds or sedge for thatch. In this way, the medieval and early modern Fens stood in contrast to the rest of England, which was primarily an arable agricultural region.
Since the advent of modern drainage in the 19th and 20th centuries, the Fens have been radically transformed. Today, arable farming has almost entirely replaced pastoral. The economy of the Fens is heavily invested in the production of crops such as grains, vegetables, and some cash crops such as rapeseed.

Areas of the Fens

Drainage in the Fenland consists of both river drainage and internal drainage of the land between the rivers. The internal drainage was organised by levels or districts, each of which includes the fen parts of one or several parishes. The details of the organisation vary with the history of their development, but the areas generally include:

Great Level

The Great Level of the Fens is the largest region of fen in eastern England: including the lower drainage basins of the River Nene and the Great Ouse, it covers about. It is also known as the Bedford Level, after Francis Russell, 4th Earl of Bedford, who headed the so-called adventurers in the 17th-century drainage in this area; his son became the first governor of the Bedford Level Corporation. In the 17th century, the Great Level was divided into the North, Middle and South Levels for the purposes of administration and maintenance. In the 20th century, these levels were given new boundaries; they included some fens that were never part of the jurisdiction of the Bedford Level Corporation.

The South Level lies to the southeast of the Ouse Washes and surrounds Ely, as it did in the 17th century.
The Middle Level lies between the Ouse Washes and the Nene, but historically was defined as between the Ouse Washes and Morton's Leam, a 15th-century canal that runs north of the town of Whittlesey.
The North Level now includes all of the fens in Cambridgeshire and Lincolnshire between the Nene and the River Welland. It originally included only a small part of these lands, including the ancient parishes of Thorney and Crowland, but excluding most of Wisbech Hundred and Lincolnshire, which were under their own local jurisdictions.File:Bylaws for the drainage of Deeping Fen.jpg|right|thumb|The former by-laws of Deeping Fen at Pode Hole near Spalding
Bourne and Deeping Fens

Bourne Fen and Deeping Fen lie in the southern most parts of Lincolnshire, between the Rivers Welland and the Bourne Eau with the River Glen running between the two Fens and the area covers both the town of Bourne as well as The Deepings including the villages of Langtoft and Baston.

Black Sluice Level

The Black Sluice Level, also known as the Black Sluice District, was first drained in 1639 and extends from the Glen and Bourne Eau to Swineshead and then across to Kirton. Its waters is carried mostly though the South Forty-Foot Drain through to the Haven at Boston though the Black Sluice. Also this area includes the market town of Spalding and the ancient village of Sempringham.
The above were all redrained at one time or another after the Civil War.

Holland, Wildmore, West and East Fens

These areas cover the northern most part of the Fens from Boston right up as far north west as Washingborough near Lincoln along the course of the River Witham and to the north east it extends up as far as the edge of the Lincolnshire Wolds to the seaside town of Skegness.

The Witham Commission Fens:
*First District: from Washingborough to Billinghay Dales
*Second District: Blacksluice – Holland Fen
*Third District: north of the River Witham above Bardney
*Fourth District: East, West and Wildmore Fens and the Townland from Boston to Wainfleet
*Fifth District: Kyme Eau to Billinghay Skirth
*Sixth District: Blacksluice – Helpringham Eau to Kyme Eau

These were drained in the 18th and 19th centuries.

Formation and geography

At the end of the most recent glacial period, known in Britain as the Devensian, ten thousand years ago, Britain and continental Europe were joined by the ridge between Friesland and Norfolk. The topography of the bed of the North Sea indicates that the rivers of the southern part of eastern England flowed into the Rhine, thence through the English Channel. From the Fens northward along the modern coast, the drainage flowed into the northern North Sea basin. As the ice melted, the rising sea level drowned the lower lands, leading ultimately to the present coastline.
These rising sea levels flooded the previously inland woodland of the Fenland basin; over the next few thousand years both saltwater and freshwater wetlands developed as a result. Silt and clay soils were deposited by marine floods in the saltwater areas and along the beds of tidal rivers, while organic soils, or peats, developed in the freshwater marshes. Fenland water levels peaked in the Iron Age; earlier Bronze and Neolithic settlements were covered by peat deposits, and have only recently been found after periods of extensive droughts revealed them. During the Roman period, water levels fell once again. Settlements developed on the new silt soils deposited near the coast. Though water levels rose once again in the early medieval period, by this time artificial banks protected the coastal settlements and the interior from further deposits of marine silts. Peats continued to develop in the freshwater wetlands of the interior fens.
The wetlands of the fens have historically included:

Washes: these are places such as tidal mud flats and braided rivers, which are sometimes exposed and at other times covered with water.
Salt marsh: this is the higher part of a tidal wash, on which salt-adapted plants grew.
Fen: this is a broad expanse of nutrient-rich shallow water in which dead plants do not fully decay, resulting in a flora of emergent plants growing in saturated peat.
Moor: this developed where the peat grew above the reach of the land water which carried the nutrients to the fen. Its development was enabled where the fen was watered directly by rainfall. The slightly acidic rain neutralized the hydroxide ions of the peat, making it more suitable for acid-loving plants, notably Sphagnum species. This is the same as bog, but the word moor was applied to this acid peatland occurring on hills. These moors disappeared in the 19th century. Researchers did not think that the Fenland had this kind of peat, until the discovery of archaeological and documentary evidence showing that it did until the early 19th century.
Waters: these have included:
*tidal creeks, which reached from the sea into the marsh, the Townlands and in some places, the fen. They were named only if big enough to be regarded as havens
*meres, or shallow lakes, which were more or less static but aerated by wind action
* many rivers, both natural and artificial

Major areas for settlement were:

Townlands, a broad bank of silt, on which the settlers built homes and grew vegetables for households
fen islands: areas of higher land, which were never covered by the growing peat
fen edges: uplands surrounding the fens

In general, of the three principal soil types found in the Fenland today, the mineral-based silt resulted from the energetic marine environment of the creeks, the clay was deposited in tidal mud-flats and salt-marsh, while the peat grew in the fen and bog. The peat produces black soils, which are directly comparable to the American muck soils. A roddon, the dried raised bed of a watercourse, is more suitable for building than the less stable peat.
Since the 19th century, all of the acid peat in the Fens has disappeared. Drying and wastage of peats has greatly reduced the depth of the alkaline peat soils and reduced the overall elevation of large areas of the peat fens. It is also recorded that peat was dug out of the East and West Lincolnshire fens in the 14th century and used to fire the salterns of Wrangle and Friskney. In later centuries it was used locally for winter fuel and its digging controlled by the Duchy of Lancaster.
Written records of earthquakes in the Fen area appear as early as 1048. According to Historia Ingulfi, p. 64, this took place in Lincolnshire. In 1117 one affected Holland, Lincs, "endangering and injuring Crowland Abbey". In 1185 Lincoln was damaged. In 1448 a shock was recorded in south Lincolnshire. In 1750 John Moore records a severe shock attended by a rumbling noise in Bourn after midday. This was felt in Lincolnshire, Leicestershire and Northamptonshire. Houses tottered, slates, tiles and some chimneys fell. As it was a Sunday, some people ran out of the churches "in great consternation". In 1792 another shock was also felt in Bourne and neighbouring towns.