Following the end of the last Ice Age, the fenland area consisted of a brackish freshwater swamp, traversed by sluggish rivers, whose outfalls were inefficient. The majority of the Fens were therefore under water or waterlogged for all or much of the year. Within the Fens, the life cycle of vegetation over the centuries produced an extensive layer of peat up to 30 feet (9 metres) thick in places. Rising above this layer of peat were the clay ‘islands’ on which the local settlements were established. The most famous of these was Ely but within the Middle Level area, a clay ridge ran southwards from March, on which the town became established.
The Romans undertook some river works in March, where they diverted the old course of the Nene through the settlement and also on Well Creek; the primary purpose of such works being to improve the navigation and trade routes. In early times the River Ouse crossed the Middle Level, its course basically running south east to north west and across the present day Ouse Washes, to outfall at Wisbech (Ousebeach).
There had been schemes, comparatively small in scale, to drain areas of the Fens in mediaeval times. With the accession of James I in 1603 however, there was a renewed drive for drainage. The population was growing, there was a greater need for food production and the fertile nature of the Fens was recognised as making them potentially very productive. An Act of Parliament allowed land owners to give up land to those who would drain it, but this was often used by larger landowners as an excuse to dispossess previous owners.
One of the major landowners in the Fens at this time was Francis Russell, the 4th of Earl of Bedford, who owned extensive holdings around Thorney, near Peterborough.
He and a group of 13 other ‘Adventurers’ set out and agreed on a project to ‘drain the Fens’. The cost of the project led in time to them being joined by over 100 others and in the absence of an English engineer considered sufficiently competent or experienced, the Dutch Engineer Cornelius Vermuyden was employed to undertake the work. His scheme, undertaken in the 1630’s, employed the principle that the most effective way to evacuate excess flows was through a network of long straight cuts which would get such flows quicker to the sea and a number of these cuts were constructed; the most significant locally being the Old Bedford River from Earith to Salters Lode, which cut off the meandering course of the Ouse.
Disputes arose, however, over the precise meaning of ‘drain the Fens’, with some of the adventurers considering that this had meant secured summer grazing, while others were convinced that they had paid to have their land made able to grow arable crops. Court battles followed and while the Adventurers were initially successful, the decision in their favour was overturned in a subsequent court case the following year. The increasing cost of the work also led to many of the Adventurers, on both sides, losing their fortunes.
The task was made considerably more difficult by the total opposition of the Fen folk to the drainage. For generations; they had enjoyed a way of life almost foreign to the rest of the country, comprising fishing, fowling, sedging and other similar activities. They saw the drainage scheme as removing their way of life and their opposition, often manifested in the blocking or infilling of the newly cut drains increased both the length of time and cost of the works.
About this time, King Charles I saw an opportunity to increase his profile and his wealth base by supporting the drainage scheme and taking 12,000 acres of Fen lands for the Crown. Charles also proposed the construction of a summer palace at Manea (to be renamed ‘Charlemont’). The Fen people contacted their local MP, who declared that he would oppose the drainage scheme as ‘contrary to the law of God and nature’; a view that would not, as time would show, always be one that Oliver Cromwell adhered to, as during the Commonwealth period, he actively supported the latter drainage works.
The outbreak of the Civil War put paid to Charles’ ambitions and, it appeared, to the drainage schemes. However, while expressing opposition while in ‘opposition’ the Commonwealth government quickly agreed that a project to make the Fens suitable for agriculture should proceed. Vermuyden was therefore recalled to the Fens and designed a second scheme, again involving the construction of long straight cuts, although a rival scheme, involving the embanking of the existing rivers was also proposed by a second Dutch engineer, Westerdijk. At this stage, in the Middle Level area, watercourses such as the Forty Foot, Sixteen Foot and Twenty Foot were cut as well as the New Bedford, or Hundred Foot River, running parallel to the Old Bedford. In addition, since at times the rivers would not be able to contain the flows coming down them, the Ouse or Hundred Foot Washes were constructed between the two Bedford rivers, to contain these flows. By the time Vermuyden left the Fens in 1656, the benefits of drainage facilitating arable cropping were becoming evident.
The newly constructed drainage network needed an organisation to maintain it and, as it crossed several counties, it was decided to create a new organisation, the Bedford Level Corporation, to have jurisdiction over the system. Originally established under the Commonwealth, the Corporation was subsequently recreated in 1663, following the accession of Charles II.
The Corporation evidently considered that the construction of the drainage system marked an end to the need for significant capital works, with routine maintenance only being the required order of the day. Their minutes, going back to the inaugural “Restoration” meeting in 1663 survive, as do some of the payment records and receipts for land taken.
However, by the end of the seventeenth century, problems with the drainage of the Bedford Level were occurring. Gravity drainage was becoming more difficult and suggestions began to be made that the rivers were ‘rising’, with mutterings about this being due to the construction of long straight cuts being contrary to the laws of ‘God and Nature’.
It soon became clear, however, that it was not that the rivers were rising but that the land was shrinking. Peat is essentially water and when efficiently and effectively drained, it ‘vanishes’ with the ‘fen blows’ adding to the problems. Within a matter of forty years, windmills and occasionally ‘donkey mills’ were being established and, as the shrinking peat exposed roddens, clay ridges and other areas less prone to shrinkage, individual catchments within the Level developed, which prompted groups of landowners to erect larger more communal pumps, usually under Acts of Parliament, which set up local Commissioners, with powers to levy taxes to pay for the upkeep of the pumps and watercourses. These in time became the internal drainage boards that still exist within the Middle Level today.
Initially the Middle Level was simply an administrative part of the Bedford Level, which had divided itself into North, Middle and South Levels.
Towards the end of the eighteenth century, however, the Middle Level felt that more local works and greater local expenditure was required within that area than the Bedford Level were willing or able to undertake. Between 1810 and 1862, a series of Acts of Parliament were passed which initially gave more powers, including fund raising, to the Middle Level and finally legally separated the Middle Level from the Bedford Level, thus creating the present Middle Level Commissioners as a legally separate entity. The Middle Level Commissioners were constituted as a statutory corporation.
Despite this progressive separation from the Bedford Level the Middle Level still had to deal with the problem of peat shrinkage. Originally, the majority of the Middle Level area drained via gravity to the River Ouse at Salters Lode, via Well Creek, with excess flows being diverted into a washland, Tongs Wash, linked to Well Creek at Nordelph, where they could be stored until falling river levels allowed the water to be let back into the system. The remainder of the area drained to the Old Bedford via the Forty Foot River and Welches Dam. There was also originally no connection between the Forty Foot and Sixteen Foot Rivers. By the early years of the nineteenth century, however, gravity drainage at these locations was proving less and less efficient and, under powers conferred by the Middle Level Act 1844, a new watercourse, the Middle Level Main Drain, was constructed from the downstream end of the Sixteen Foot at Three Holes to Wiggenhall St Germans, near Kings Lynn, where tide levels were up to 7 feet (2.2 metres lower). The Main Drain discharged to the River Ouse through sluices at Eau Brink, with the sluicekeeper living in the property at Eau Brink which is now privately owned. The construction of this new watercourse meant that discharge through Well Creek to Salters Lode and via the Forty Foot were no longer required. The use of Tongs Wash also ceased. In 1862 however, the sluices burst and a large area of Marshland was inundated by the tide for a considerable period.
By the first half of the twentieth century, the continued peat shrinkage, allied with faster run off from land meant that the gravity discharges through the Main Drain were no longer efficient. The continued peat shrinkage is most obviously seen at Holme Fen near Peterborough, where a post for the Crystal Palace Exhibition was sunk into the ground in 1848 so that its very top was at ground level. By the end of the nineteenth century along a further 12 feet 6 inches (3.8 metres) of peat had disappeared leaving much of the post well above the shrunken ground level. The post was not of course even placed into the ground until nearly 200 years after the main drainage scheme was completed.
As a result of this continued shrinkage, the St Germans pumping station was therefore constructed at Wiggenhall about ½ mile upstream of the former sluices to become the primary discharge mechanism. Originally built with a capability to discharge 40 cumecs, its original three diesel powered pumps were improved in 1951 with the installation of 2 electric motors and a fourth pump. This new configuration of 2 diesel and 2 electric pumps had a maximum discharge capacity of 70 cumecs. This work also marked the end of the period when any gravity drainage was possible, as prior to 1951, some gravity discharge had been possible at St Germans, via the sluices incorporated into the station. St Germans continued to operate in this way for the next 50 years.
By 2005, however, a study showed that increasing run off, land shrinkage and development within the Middle Level area necessitated the improvement of the pumping facility. Following consideration of various options a new St Germans pumping station was therefore built just downstream of the original facility with a discharge capacity of up to 100 cumecs, and came on line in April 2010. It is the largest pumping station in Great Britain.
The position of the St Germans’ outfall in the north east of the Middle Level area gave rise to an added difficulty in dealing with the continued peat shrinkage, as the majority of the remaining peat was concentrated in the south west of the Middle Level, around Sawtry and Holme. To deepen the Middle Level watercourses further to take such flows would present problems of watercourse stability, particularly in the areas from which the peat had (almost) disappeared.
It was therefore decided to construct a Booster Station at Pondersbridge on Bevills Leam, which would pump excess water from the peat areas into the remainder of the Middle Level ‘pond’, thus removing the need to excessively deepen the downstream channels.
At the same time, steps were taken to cut off the flows from various highland brooks that flowed into the west of the catchment. The Middle Level Catchwater Drain, constructed at the end of the 1970’s intercepted these brooks and conveyed their flows to the Great Raveley Drain. A sluice, the ‘Control Sluice’ was constructed across this Drain to divert high flows, at times when the receiving downstream watercourses could not cope. The diversion of water takes place into Woodwalton Fen NNR, in which water is held until levels within the river channels have fallen, when water is let back, by gravity, into the system.
Woodwalton Fen is a European site of conservation importance and also forms part of the Great Fen Project, in which the Commissioners are partners and which aims to link Woodwalton and Holme Fens and create a variety of habitats. We are also looking at suitable opportunities to store water within the Project Area to meet environmental concerns over the use of Woodwalton Fen as a storage area of first resort.
The majority of the Middle Level watercourses are embanked, which leads to the need to ensure that bank heights are maintained at suitable levels. A continued programme of bank surveying and, where necessary, raising, is undertaken.
In addition to their flood defence function, the Commissioners are also, by length of available waterway, the 4th largest navigation authority in the UK, with 100 miles (160km) of navigable channel. The Middle Level waterways also include the Link Route between the neighbouring Gt Ouse and Nene systems of the Environment Agency and therefore links the Great Ouse to the canal system to the west. There are 6 locks within the Middle Level system including the entrance/exit locks at Stanground (near Peterborough) and Salters Lode (near Downham Market) the latter being the former northern discharge channel. Much of the Commissioners’ navigation function is still governed by the Nene Navigation Act 1753 and historically there were separate drainage and navigation commissioners within the Middle Level system. The difficulties of having two separate sets of Commissioners exercising competing jurisdiction over waterways which needed to be very closely managed with water levels managed in an integrated way led, however, to the creation of the present Commissioners, with responsibilities for both flood defence and navigation in 1862. This enables integrated water management to occur and proper overall control to be maintained within a system totally dependent on daily management of water levels.
Apart from rainfall, the only material source of water in summer for the Middle Level catchment is the River Nene at Stanground and water is fed into the system via the Lock structure. Historically, the original course of the Nene went through the Middle Level and the Commissioners rights to take the inflows that were originally directed to their system was preserved by section 59 of the Middle Level Act 1848.
The availability of water in summer has always been and remains a major problem for the Commissioners and many landowners have attempted to provide increased security for supplies by constructing reservoirs which can economically be filled with water during the winter time.
In the Middle Level area, because most of the land is below sea level, excess rainfall has to be pumped, in some places three times, before getting to the sea. This makes the proper management of water and water levels, through such means as Sustainable Drainage, very important indeed to prevent or control the risk of flooding.
The link below is a short animation from CIRIA called 'Ever wondered where the rain goes?'. This gives a demonstration of how changes in the natural water cycle can be managed.
The link below opens a PDF document with more information about the Middle Level Commissioners work and responsibilties.