Polders in the Fens in England

Dutch hydraulic engineers were particularly involved in the reclamation of the Fens. The best known of them was Cornelis Vermuyden from the Province of Zeeland, who probably came to England in 1621 to help his brother-in-law Joachim Liens with a proposed reclamation project. When this failed, Vermuyden became involved in repairing a breach in the banks of the River Thames at Dagenham. In 1626, he was commissioned by King James I to reclaim Hatfield Chase, an area of approximately 28,400 hectares, of which the King owned the largest part. The investors in the project - many of whom were Dutch - received 9,877 hectares of the reclaimed lands, of which Vermuyden himself received 1,843 hectares.

In 1629 Vermuyden was asked to undertake the reclamation of the Great Level in the Fens. The plan was carried out on behalf of Francis, the 4^th Earl of Bedford, who owned a large part of the area. As a result of his and his son's involvement, the area eventually became known as the Bedford Level. Vermuyden was both the director of the project and an investor. Canals were dug and existing canals were straightened to improve the drainage of the main rivers - the Don, Idle, Aire and Went.

The project met with much opposition from the local population, and the work - particularly the construction of a new course for the Don - was expensive, so the project was not a financial success. However, it did establish Vermuyden's reputation in England as a water manager and earned him a knighthood. The settlers included Protestant families who had fled from the Netherlands. The most important feature of the project was the Seventy Foot of Bedford River (later the Old Bedford) which ran for about 32 km (20 miles) straight, and was used to divert the waters of the River Ouse from Earith to Denver. It shortened the course of the river by about 20 km (12 miles). A number of main canals and numerous minor canals were also dug and sluices constructed. The dikes along the rivers were initially made of peat and clay, but as the peat dried out they often broke. They were later extensively repaired using clay alone.

However, there was continued opposition from the local population. Their objection was not so much to the reclamations, but to the issuing of the reclaimed lands to those involved in the reclamations, which reduced the area of their common lands. Large areas also continued to be flooded. King Charles I therefore appointed a new Water Management Commission in 1638 and took on the role of the main entrepreneur himself. On his behalf, Vermuyden drew up a report on reclamations in the Great Fens, with advice on how to improve the situation in the Great Level. The outbreak of the Civil War in England brought the work to a halt.

In 1649, reclamation work resumed. The Great Level was divided into three parts: the North, Middle and South Levels. The most important work in this phase was the construction of the Hundred Foot Drain, or New Bedford River. Significantly higher dikes were built on both sides, creating a vast marshland area where water from the rivers could be stored during floods. Several new watercourses were also dug, particularly in the Middle Level area, and improvements were made to existing watercourses. To prevent the tide from reaching the old course of the Ouse, Denver Sluice was built in 1653. New roads were also built. Less was done on the South Level. Vermuyden's main proposal for this area was the construction of a diversion canal for the Little Ouse, Wissey and Lark rivers, which ran around the eastern edge of the Fens. The project was finally realised some three hundred years later, in 1964.

The 17^th century drainage and land reclamation projects were successful, but by the end of the century the condition of the reclaimed lands was deteriorating. The peat was shrinking steadily, while on land that was ploughed and burned the peat was blown away and the topsoil oxidised. Rapid subsidence, especially in the Great Level, caused the land surface to fall below the level of the adjacent rivers and drains. Windmills were introduced on a large scale.

In the mid-18^th century, a number of improvements were made to the Fens. Attempts were also made to reclaim the remaining common lands. This still met with strong opposition from the local population, so that large areas remained in their original marshy state. The complete reclamation of the Fens took place during the 19^th century. In addition, drainage was significantly improved by the construction of several steam-powered pumping stations.

The Fens are now largely below sea level. The last phase of reclamation was accompanied by further improvements in water management. The landscape is mostly determined by the developments of the 19^th century. However, these would not have been possible without the 17^th and 18^th century reclamation projects, in particular the construction of the main canals. The total area of drainage in England is now around 900,000 hectares.