Monday, 13 July 2009

Somerset Levels


The Somerset Levels (or the Somerset Levels and Moors as they are called less commonly but more correctly) is a sparsely populated coastal plain and wetland area of central Somerset, England, between the Quantock and Mendip hills.
The Somerset Levels consist of marine clay "levels" along the coast, and the inland (often peat based) "moors". The area borders the Severn Estuary with its very high tidal range which used to cause marine flooding, but this is now largely controlled by various sea defences. The Levels are divided into two by the Polden Hills, with the catchment areas of the River Parrett to the south, and the rivers Axe and Brue to the north. This area is separate from the North Somerset Levels, which is located inland from Weston-super-Mare.
The total area of the Levels amounts to approximately 160,000 acres (650 km2). It broadly corresponds to the administrative district of Sedgemoor but also includes the south east of Mendip district. Approximately 70% of the area is grassland and 30% is arable.
Discussions are taking place concerning the possibility of obtaining World Heritage Site status for the Somerset Levels and Moors as a "cultural landscape". It has been suggested that if this bid were successful, it could improve flood control, but only if wetland fens were created again
Geology and sedimentology Glastonbury Tor.

The Levels and Moors are a largely flat area in which there are some slightly raised parts, called "burtles" as well as higher ridges and hills. It is an agricultural region typically with open fields of permanent grass, surrounded by ditches with willow trees. Access to the Moors and Levels is by "droves", i.e. green lanes. The Levels are a coastal sand and clay barrier about 6 metres (20 ft) above mean sea level (roughly west of the M5 motorway) whereas the inland Moors can be 6 metres (20 ft) below peak tides and have large areas of peat. The geology of the area is that of two basins mainly surrounded by hills, the runoff from which forms rivers that originally meandered across the plain but have now been controlled by embanking and clyses (the local name for a sluice). The area is prone to winter floods of fresh water and occasional salt water inundations which have occurred, the worst of which in recorded history was the Bristol Channel floods of 1607, which resulted in the drowning of an estimated 2,000 or more people, with houses and villages swept away, an estimated 200 square miles (518 km2) of farmland inundated and livestock destroyed. A further severe flood occurred in 1872-1873 when over 107 square miles (277 km2) were under water from October to March.
Although underlain by much older Triassic age formations that protrude to form what would once have been islands—such as Athelney, Brent Knoll, Burrow Mump and Glastonbury Tor—the lowland landscape was formed only during the last 10,000 years, following the end of the last ice age. Glastonbury Tor is composed of Upper Lias Sand. The Poldens and the Isle of Wedmore are composed of Blue Lias and Marl, while the Mendips are largely Carboniferous Limestone. The peak of the peat formation took place in swamp conditions around 6,000 years ago, although in some areas it continued into medieval times.

Drainage

The River Brue in an artificial channel draining farmland near Glastonbury.

The moors and levels are formed from a submerged and reclaimed landscape. Early attempts to control the water levels were possibly made by the Romans (though records only date from the 13th century) but were not widespread.
There was a port at Bleadney on the river Axe in the 8th century that enabled goods to be brought to within 3 miles (5 km) of Wells. In 1200 a wharf was constructed at Rackley near Axbridge. The Parrett was navigable up as far as Langport in 1600, with 15-20 ton barges. The Domesday Book recorded that drainage of the higher grounds was under way, though the moors at Wedmoor were said to be useless. In the Middle Ages the monasteries of Glastonbury, Athelney and Muchelney were responsible for much of the drainage. In 1129 the Abbot of Glastonbury was recorded as inspecting enclosed land at Lympsham. Efforts to control flooding on the Parrett were recorded around the same date. In 1234, 722 acres (2.9 km2) were reclaimed near Westonzoyland.

Curry Moor pumping station

Flowing through the Moors and Levels to provide the main drainage outlets are the rivers Axe, Brue, Huntspill, Parrett, Tone and Yeo, together with the King's Sedgemoor Drain, an artificial channel into which the river Cary now runs. Previously it ran into the Tone while the Brue previously ran through Meare Pool (now drained) and the Panborough Gap, and then into the Axe. Another accomplishment in the Middle Ages was the construction of the Pillrow Cut joining the Brue and Axe, which was tidal. In 1500 there was said to be 70,000 acres (283 km2) of floodable land of which only 20,000 acres (81 km2) had been reclaimed. In the time of King James plans were made to drain and enclose much of Sedgemoor, which the lords supported but the commoners opposed and nothing came of this plan. In 1632 Charles I sold the crown's interest in the scheme, and it was taken over by a consortium including Sir Cornelius Vermuyden, a Dutch drainage engineer, but the start of the work was delayed by the English Civil War, and later defeated in parliament due to local opposition. In 1638 it was reported that nearly 2,600 acres (11 km2) of Tealham and Tadham Moors were not reclaimed, with a total of 30,500 acres (123.43 km2) being undrained. Between 1785 and 1791 much of the lowest part of the peat moors was enclosed. In 1795 John Billingsley advocated enclosure and the digging of rhynes (a local name for drainage channels, pronounced "reens") between plots, and wrote in his Agriculture of the County of Somerset that 4,400 acres (18 km2) had been enclosed in the last 20 years in Wedmore and Meare, 350 acres (1.4 km2) at Nyland, 900 acres (3.64 km2) at Blackford, 2,000 acres (8 km2) at Mark, 100 acres (0.4 km2) in Shapwick and 1,700 acres (7 km2) at Westhay. At Westhay Moor in the early 1800s it was shown how peat bogs could be successfully drained and top-dressed with silt from flooding, creating a very rich soil.
Little attempt was made during the 17th and 18th centuries to pump water, possibly because the coal driven Newcomen steam engines would have been uneconomic. It is not fully understood why windmills were not employed as they were on the Fens of East Anglia, and only two examples have been recorded on the levels. One was at Bleadon at the mouth of the River Axe, where a sea wall had been built, and the other at Common Moor north of Glastonbury, which was being drained following a private Act of Parliament in 1721. The first steam pumping station was Westonzoyland Pumping Station in 1830 and more effective ones from 1860. Today automatic electric pumps are used.

The flooded Southlake Moor

The Huntspill river is artificial, constructed in the Second World War as a reservoir, though acting also as a drainage channel. The levels and moors are now artificially drained by a network of rhynes which are pumped up into "drains". Water levels are carefully managed by the Levels Internal Drainage Boards (IDBs) and the levels are not as intensively drained or farmed as the East Anglian fens (historically a similar area of low marsh). They are still liable to widespread fresh water flooding in winter. One of the approaches to reducing the risk of flooding within the catchment area of the Parrett is the planting of new woodlands.
Controversy about the management of the drainage and flood protection has previously involved the activities of Internal Drainage Boards. However, IDBs have been actively participating with the Parrett Catchment Partnership, a partnership of 30 organisations which aims to create a new consensus on how water is to be managed, in particular looking at new ways to achieve sustainable benefits for all local stakeholders.

Sea defences

Greylake sluice on King's Sedgemoor Drain

Much of the area is at, or only slightly above, sea level so that it was frequently flooded by the sea, a problem that was not fully resolved until the sea defences were enhanced in the early 20th century. The Parrett is the only river that does not have a clyse on it.
There was a great storm in 1703 when waves came four feet (1.2 m) over the sea walls. The sea wall was again breached in 1799 and this filled the Axe valley with sea water. In 1872 another great flood covered 7,000 acres (28 km2) and in 1919 70,000 acres (283 km2) were again inundated with sea water, which poisoned the land for up to 7 years. Since 1990 the drainage board has been charged with looking at the rhynes, cleaning them out and keeping them clear, with the Environment Agency overseeing the work. With rising sea levels the work required to maintain the current sea defences is likely to become more expensive and it has been proposed that two inland seas are created.[16] Other studies have recommended maintaining the current defences for five years while undertaking further studies of available options.

Human habitation

Route of the Sweet Track.

In prehistory it is thought that, due to winter flooding, humans restricted their use of the levels to the summer, a practice that gave rise to name of the county of Somerset (derived from Sumorsaete, meaning land of the summer people). A Palaeolithic flint tool found in West Sedgemoor is the earliest indication of human presence in the area. During the 7th millennium BC the sea level rose and flooded the valleys so the Mesolithic people occupied seasonal camps on the higher ground, indicated by scatters of flints. The Neolithic people continued to exploit the reedswamps for their natural resources and started to construct wooden track ways. These included the Sweet Track, currently the world's oldest known engineered roadway dating from the 3800s BC, and named after the peat digger who first spotted it in 1970.
The Levels were also the location of the Glastonbury Lake Village as well as two at Meare. Discovered in 1892 by Arthur Bulleid, the former remains the best-preserved prehistoric village in the United Kingdom, and was at one time inhabited by around 200 people living in 14 roundhouses.
The area continued to be used in the Bronze Age, with the population supporting themselves largely by hunting and fishing in the surrounding marsh, living on artificial islands connected by wooden causeways on wooden piles. There have been many finds of metalwork during peat cutting, which may have been devotional offerings. In the Iron Age the first permanent settlement of the higher ground occurred. A salt making industry was set up near Highbridge.

In the Roman period the extraction of sea salt continued and a string of settlements was set up along the Polden Hills. Some possible settlement sites are also known in the Draycott and Cheddar Moors and around Highbridge. The discovery at Shapwick of 9,238 silver denarii, the second largest hoard ever found from the Roman Empire, may have been linked to this industry, or to the associated local minting and counterfeiting operation.
A number of Saxon charters document the incorporation of areas of moor in estates, suggested that the area continued to be exploited. Several towns, villages and hill forts were also built on the natural "islands" of slightly raised land, including Brent Knoll, Glastonbury, and the low range of the Polden Hills. It's easy to see why the area acquired a number of legends, particularly of King Arthur and his followers, who some believe based his court at the hill fort at South Cadbury.
Alfred the Great famously burnt cakes when hiding in the marshes of Athelney, after the Danish invasion in 875. After the battle of Edington the Danish king was baptised at Aller and a peace treaty signed at Wedmore.
In 1685 the area around the Battle of Sedgemoor was fought in the Bussex area of Westonzoyland at the conclusion of the Monmouth Rebellion.

Land use
The area has few trees and is dominated by grassland, mostly used as pasture for dairy farming. The River Parrett provides a source of eels (Anguilla anguilla) and elvers during January through to May. Other local industries that once thrived on the Levels, such as thatching and basket making, are now in serious decline. Combined with the recent drop in farm incomes, this poses a potential threat to the 'traditional' nature of the area as a whole. Subsidies are paid to farmers who manage their land in the traditional way.

Willow

Willow Man.

Willow has been cut and used on the Levels since humans moved into the area. Fragments of willow basket were found near the Glastonbury Lake Village, and it was also used in the construction of several Iron Age causeways. The willow was harvested using a traditional method of coppicing, where a tree would be cut back to the main stem. New shoots of willow, called "withies", would grow out of the trunk and these would be cut periodically for use.
During the 1930s over 9,000 acres (36 km2) of willow were being grown commercially on the Levels. Largely due to the displacement of baskets with plastic bags and cardboard boxes, the industry has severely declined since the 1950s. By the end of the 20th century only around 350 acres (1.4 km2) were grown commercially, near the villages of Burrowbridge, Westonzoyland and North Curry. The Somerset Levels is now the only area in the UK where basket willow is grown commercially. For weaving the species Salix triandra (Almond Willow, Black Maul) is grown, while Salix viminalis (Common Osier) is ideal for handles, bases, and the structural members in furniture and hurdles. Products including baskets, eel traps, lobster pots and furniture were widely made from willow throughout the area in the recent past. Among the more unusual products still made are passenger baskets for hot air balloons, the frames inside the bearskin hats worn by the regiments of the Household Cavalry, and an increasing number of willow coffins.
The industry is celebrated in the form of the Willow Man (sometimes known as the Angel of the South), a 40 ft (12.2 m) tall willow sculpture by artist Serena de la Hey that can be seen from the railway and the M5 motorway to the north of Bridgwater. At Stoke St Gregory there is also a Willows and Wetlands visitor centre.

Teazel growing
An unusual crop is the growing of teazels around the River Isle near Chard on the heavy clay soils around Fivehead. These are used to provide a fine finish on worsteds and snooker table cloths.

Peat extraction
The extraction of peat from the Moors is known to have taken place during Roman times, and has been an ongoing practice since the levels were first drained. The introduction of plastic packaging in the 1950s allowed the peat to be packed without rotting. This led to the industrialisation of peat extraction during the 1960s as a major market in horticultural peat was developed. The reduction in water levels that resulted put local ecosystems at risk, with peat wastage in pasture fields was occurring at rates of 1–3 ft (0.3–0.8 m) over 100 years. Although the practice is now much reduced, at least one large firm still operates on the levels and peat lorries remain a common feature of the back roads.

Biodiversity and conservation

Shapwick Heath.

As a result of the wetland nature of the Moors and Levels, the area contains a rich biodiversity of national and international importance. It supports a vast variety of plant species, including common plants such as marsh marigold, meadowsweet and ragged robin. The area is an important feeding ground for birds including Bewick’s swan, Eurasian curlew, Common redshank, skylark, Common snipe, Common teal, wigeon and whimbrel, as well as birds of prey including the marsh harrier and peregrine falcon. A wide range of insect species is also present including rare invertebrates, particularly beetles including the lesser silver water beetle, Bagous nodulosus, Hydrophilus piceus, Odontomyia angulata, Oulema erichsoni and Valvata macrostoma. In addition, the area supports an important otter population. 282 mink (Mustela vison) have been captured, and this is encouraging Water Voles (Arvicola amphibius) to recolonise areas of the Levels where they have been absent for ten years.
The Levels and Moors include 32 Sites of Special Scientific Interest (twelve of them also Special Protection Areas), the Huntspill River and Bridgwater Bay National Nature Reserves, the Somerset Levels and Moors Ramsar Site covering about 86,000 acres (348 km2), the Somerset Levels National Nature Reserve, Shapwick Heath National Nature Reserve, and numerous Scheduled Ancient Monuments.
In addition, some 72,000 acres (291 km2) of the Levels are recognised as an Environmentally Sensitive Area, while other portions are designated as Areas of High Archaeological Potential. Despite this, there is currently no single conservation designation covering the entire area of the Levels and Moors.
A survey in 2005 discovered that 11 of the known wooden Bronze Age causeways on the Levels had been destroyed or vanished, while others were seriously damaged. The reduction in water levels and subsequent exposure of the timber to oxygen and Aerobic bacteria is the cause of the destruction.

Somerset Levels Project
This research project was started in 1964 by John Coles. It published an important series of papers on many aspects of the Levels. Possibly its most important excavations were that of the Sweet Track, for 15 years starting in 1970, and of a Jadeite axe in 1973. Eight radiocarbon determinations date axe around 3200 BC.

Shapwick Project
This project was begun by Mick Aston of Bristol University to investigate the evolution of a typical English village. A preliminary study of the village history was carried out using maps and documents, then surveys of the buildings were made together with botanical surveys. Field walking was carried out with excavation of key sites. A report on the project was published in eight volumes.

Tourism

Westonzoyland Pumping Station Museum.

Being largely flat, the Levels are well suited to bicycles, and a number of cycle routes exist including the Withy Way Cycle Route (22 miles, 35 km), Avalon Marshes Cycle Route (28 miles, 45 km), Peat Moors Cycle Route (24 miles, 39 km) and the Isle Valley Cycle Route (28 miles, 45 km). The River Parrett Trail (47 miles, 75 km) and Monarch's Way long-distance footpaths are also within the area.
There are currently four visitors' centres that aim to convey various aspects of the Levels.
The Willows and Wetlands visitor centre near Stoke St Gregory offers tours of the willow yards and basket workshops and explains the place of willow in the history of the Levels. The Somerset Willow Company also open the doors of their workshops to visitors. The Peat Moors Centre to the west of Glastonbury is dedicated to the archaeology, history and geology of the area. It also includes reconstructions of some of the archaeological discoveries, including a number of Iron Age round houses and the world's oldest engineered highway, the Sweet Track. From time to time the centre offers courses in a number of ancient technologies in subjects including textiles, clothing and basket making, as well as staging various open days, displays and demonstrations. In Glastonbury itself is The Tribunal, a medieval merchant's house containing possessions and works of art from the Glastonbury Lake Village which were preserved in almost perfect condition in the peat after the village was abandoned. Also in Glastonbury, the Somerset Rural Life Museum contains information about crafts and folk traditions on the Levels, including willow growing. The Langport & River Parrett Visitor Centre located at Langport details local life, history and wildlife. In addition, Westonzoyland Pumping Station Museum, located near the town on the River Parrett, is housed in one of the earliest steam-powered pumping stations on the Levels, dating from the 1830s. The station was closed in the 1950s. Featuring several steam engines, some built locally, the museum holds a number of live steam days each year.
Bibliography
Aston, Michael; Ian Burrow (1991). The Archaeology of Somerset. Somerset County Council. ISBN 0861830288.
Aston, Michael (1992). Aspects of the Medieval Landscape of Somerset. Somerset Books. ISBN 0861831292.
Coles, Bryony; John Coles (1986). Sweet Track to Glastonbury: Somerset Levels in Prehistory (New Aspects of Antiquity). Thames & Hudson Ltd. ISBN 0500390223.
Coles, John; S.C. Minnitt (1995). Industrious and Fairly Civilized: Glastonbury Lake Village. Somerset Levels Project. ISBN 0950712221.
John Coles. "Man and landscape in the Somerset Levels" (PDF). Archeology Data Service. http://ads.ahds.ac.uk/catalogue/adsdata/cbaresrep/pdf/021/02112001.pdf. Retrieved on 2007-06-10.
Havinden, Michael (1982). Somerset Landscape (The Making of the English landscape). Hodder & Stoughton Ltd. ISBN 0340201169.
Hill-Cottingham, Pat; Derek Briggs, Richard Brunning, Andy King & Graham Rix (2006). The Somerset Wetlands: An Ever Changing Environment. Somerset Archaeological and Natural History Society. ISBN 0861834321.

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