River Severn

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Image:Severn Aerial.jpg The River Severn (Welsh: Afon Hafren) is the longest British river, at 354 kilometres (219 miles) long; it rises at an altitude of 610 metres on Plynlimon near Llanidloes, in the Cambrian Mountains, Mid Wales, and it passes through a number of English counties, with the county towns of Shrewsbury, Worcester, and Gloucester located on its banks. The Severn becomes the Bristol Channel at its estuary, eventually discharging into the Irish Sea and the Atlantic Ocean. With an average discharge of 107 m³/s at Hawbridge (Worcestershire), the Severn is England´s largest river in terms of water flow. The largest amount of the river goes through a town called Moorings. The Severn's drainge basin area is 11,420 km². It is one of the ten major rivers in the United Kingdom.

According to some sources, the name "Severn" is derived from the name Sabrina (or "Sabern"), based on the mythical story of the drowning of a nymph in the river. Sabrina is also the goddess of the River Severn in Brythonic mythology.

1 Tributary rivers
2 Transport
- 2.1 Bridges
- 2.2 Associated canals
3 Tidal bore
4 Tidal Power
5 Industry
6 Wildlife
7 See also
8 External links

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Tributary rivers

The River Stour rises in the north of Worcestershire in the Clent Hills, near St Kenelm's Church at Frankley. It flows north into the adjacent West Midlands at Halesowen. It then flows westwards through Cradley Heath and Stourbridge were it leaves the Black Country. It is joined by the Smeslow Brook at Prestwood before it winds around southwards to Kinver, and then flows back into Worcestershire. It then passes through Wolverley and Kidderminster to join the Severn at Stourport-on-Severn.

A tributary of the Severn, called the River Teme, joins it just below Worcester and above Kempsey.

One of the several rivers named Avon joins the Severn at Tewkesbury, Gloucestershire. That same Avon also flows through Stratford-upon-Avon.

The port of Bristol is located at the mouth of the Severn, where another River Avon flows into it. The River Wye flows into the Severn slightly upstream of the Avon and forms the boundary between England, specifically the Forest of Dean, and Wales, with the town of Chepstow (Casgwent in Welsh) at the confluence, giving an important strategic position in yester-year and was the main route into South Wales, before the two bridges were built.

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Transport

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Bridges

The Severn Tunnel carries the Great Western Main Line under the estuary. The two bridges of the Severn crossing carrying roads (opened in 1966 and 1996) link Wales with the southern counties of England and are among the most important in Britain. The Severn is bridged at many places, and many of these bridges are notable in their own right, with several designed and built by the engineer Thomas Telford. (See List of Severn bridges for more.)

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Associated canals

The Staffordshire and Worcestershire Canal, the Worcester and Birmingham Canal, the Droitwich Canals and the Herefordshire and Gloucestershire Canal are joined to the Severn.

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Tidal bore

A curious phenomenon associated with the lower reaches of the Severn is the tidal phenomenon known as the bore. The river's estuary, part of the Bristol Channel, has the second largest tidal range in the world — about 15 metres, exceeded only (and only just by a couple of feet) by the Bay of Fundy in Canada — and at certain combinations of the tides, the rising water is funnelled up the estuary into a wave that travels rapidly upstream against the river current; enthusiasts even attempt to surf along on the wave, which can be 2 m high. (Note that the Gloucester Harbour Trustees, as competent harbour authority for this part of the river, explicitly advise against this pastime.) Being the onset of the flood tide it is accompanied by a rapid rise in water level which continues for about one and a half hours after the bore has passed. The Severn Bore is a natural example of a self-reinforcing solitary wave or soliton.

The bore forms somewhat upstream of the Port of Sharpness, which is also the Southern terminus of the Gloucester and Sharpness Canal. The canal was built in the 1820s to enable safer passage of trading ships to Gloucester. Just North of the Port are the remains of the Severn Railway Bridge, which bridged the river until it was badly damaged in a ship collision in 1960. Between Purton and Sharpness is an area known as The Ships' Graveyard, where many disused barges were scuttled along the bank to reduce erosion, which was threatening to destroy the banks of the canal. Several of these barges have 'concrete' sides and were intended for use in World War 2; there have been plans to restore some of them, as of historical interest.

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Tidal Power

Template:Main The huge tidal range and high level of surrounding industry and population have long made the Severn estuary a focus for tidal energy schemes and ideas. Plans for a Severn Barrage - running 16 km from near Cardiff to near Weston Super Mare - would generate a massive 8640 MW when the tide flows, and have been discussed for several decades now. The UK Government shelved the plans in the late 80's due largely to cost issues and local environmental concerns. However, this was before recent huge rises in the price of energy and before Global Warming had been heard of.

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Industry

A six-mile stretch of the Severn valley in Shropshire, known as the Ironbridge Gorge, was designated a World Heritage Site by UNESCO in 1986. Its historic importance is due to its role as the centre of the iron industry in the early stages of Britain's Industrial Revolution. Ironbridge gets its name from the bridge across the Severn, built in 1779, which was the first cast-iron bridge ever constructed.

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