The Fens

The Fens, also known as the Fenlands, are a low-lying region in eastern England. This area is a National Character Area because of its unique landscape and biodiversity. It sits inland from the Wash, a large bay. The region covers parts of Lincolnshire, Cambridgeshire, Norfolk, and Suffolk.

Some scholars debate if the Isle of Axholme in north Lincolnshire belongs here. While it has a similar environment, it is not physically connected to the rest of the East Anglian Fenland.

The geography of the Fens is defined by its extreme flatness. Most of the land lies within a few metres of sea level. In fact, some parts now sit below mean sea level. This happened because of land drainage and the subsequent shrinkage of peat. Peat is an organic soil formed from dead plants that do not fully decay in wet conditions. Holme Fen in Cambridgeshire is one of the lowest spots in the United Kingdom.

To understand how the Fens formed, we must look back ten thousand years. During the Devensian glacial period, melting ice caused sea levels to rise. This flooding drowned inland woodlands and created vast wetlands. The environment split into different types based on water chemistry. Saltwater marshes formed near the coast where marine floods deposited silt and clay. In the freshwater interior, organic peat developed in the marshes.

Historically, the wetlands were divided into several distinct types. Washes were tidal mud flats or braided rivers that were sometimes covered by water. Salt marshes were higher tidal areas where salt-adapted plants grew. Fens were shallow, nutrient-rich waters filled with emergent plants. There were also moors, which were acid peatlands formed where rainfall neutralized the peat. These moors disappeared during the 19th century. Some areas also featured meres, which were shallow, static lakes.

Managing the water has required massive engineering efforts over many centuries. Without artificial drainage, the Fens would flood frequently, especially in winter. This happens when heavy water flows down from surrounding uplands. To prevent this, people built a system of dykes and drains. These are man-made channels used to move water away from the land.

The area is also protected by drainage banks and automated pumping stations. In the past, windpumps were used, and later, steam engines helped move water.

The drainage of the Great Level is a major part of this history. This large region includes the drainage basins of the River Nene and the Great Ouse. In the 17th century, it was known as the Bedford Level. This name comes from Francis Russell, the 4th Earl of Bedford, who led investors in the drainage project. The area was divided into the North, Middle, and South Levels for administration. Today, the drainage is organized by specific districts or levels to manage internal water flow.

This engineering transformed the economy of the region. In the medieval period, people practiced pastoral farming, fishing, and fowling. They also harvested reeds and sedge for thatch. Today, arable farming has almost entirely replaced pastoral activities. The Fens have become a massive producer of grains, vegetables, and rapeseed. The soil is incredibly fertile. It contains approximately half of all the grade 1 agricultural land in England.

Despite the flat landscape, certain high spots exist. Historically, these were called "islands" because they stayed dry during floods. The largest was the 23-square-mile Kimmeridge Clay island. The cathedral city of Ely was built on this island. Other significant settlements include Boston, Spalding, and King's Lynn. Because of its many former monasteries, the Fens have been called the "Holy Land of the English."