Severn bore

Severn boating

The Severn Bore

bore wave from severn-boating

Many times a year, the high Spring tide forms a wave that surges up the River Severn as a wall of water.
As the bore passes, the depth of water in the river instantly rises and may flood the bank.
The flow of the river is reversed and remains so until the tide begins to ebb.
The height of the bore depends on a number of factors but the most important is the tidal range.
Depending on the depth of water, the bore may be a smooth wave or have a breaking crest.
The wall of a large bore may be 2 metres high and travel at some 14 knots.

Where to see the Severn Bore

There are numerous viewing points on the river bank anywhere north of about Newnham.

The most popular sites, with easy access from roads are at Over Bridge, Minsterworth and Stonebench.

Stonebench is also within walking distance of the Sharpness canal.

If a large Severn bore is predicted there will be many hundreds of visitors.

A remarkable photo of surfers riding the Severn bore in April 2007. It was taken from a microlight aircraft by Mark Humpage. The photograph shows that a series of waves, rather than a single wave, may constitute a bore. Note that in the shallow water near the shore, the waves collapse and break The largest wave of this bore was just over a metre in height.
	Modified from a photo by Mark Humpage (c) mhWeather

small severn bore with surfers at Stonebench

A small bore wave surging up the River Severn. For scale note the rigid inflatable on the tidal side.

Picture taken from the bank at Stonebench where the river channel is narrow.

The bore wave is interrupted by weirs near Gloucester but the effects of the bore continue upto Tewkesbury.

Remember, as the bore passes it will often break violently along the bankside; the river level will instantly rise and will often flood the adjacent area.

Visitors should choose their viewing point with care.

When to see the Severn Bore

Although bores on the River Severn are frequent, it is only the spectacular ones that are likely to interest most visitors.

Because they are tidal features, it is posssible to predict dates and approximate times of arrival.

Predictions, with dates and times, may be obtained online from the Environment Agency (see Severn boating links)

Surfing the Bore

The river above Sharpness is hazardous and this is no place for beginners! But experienced surfers frequently do surf the wave.

For details visit the Striguil Bore Page .

Tidal bores of the World

In places where there is a large tidal range, many rivers have a tidal bore. Alternative names, in different parts of the world, include aegir, eagre, pororoca and mascaret

The bore on the Qiantang River in China, with a height of nearly 9m, is the largest in the world.

Disclaimer: All linked sites are believed to be in the public domain. They are verified regularly but the Severn-boating page accepts no reponsibility for the nature or accuracy of information on those sites.