Storm Event

The 1607 British Channel Floods caused the greatest loss of life from a natural catastrophe in the UK during the last 500 years

Severity ? 6

Source

According to eyewitness accounts of the weather, the storm surge appears to have been due to gale force westerly or south-westerly winds (Horsburgh and Horritt, 2007). There was previously a theory that the storm surge was a tsunami (Bryant and Haslett, 2002. This theory was based heavily on inferences from historical erosion of wetlands; and the significant volumes of water and massive coastal damage that can be caused by storm surges were underestimated (Horsburgh and Horritt, 2007). However, Horsburgh and Horritt (2007) used numerical modelling to confirm that the exceptionally high tide, combined with a storm surge from this eyewitness weather, is capable of producing the flooding that occurred. In addition, areas of the eastern side of the UK also flooded on the same day, although in the evening (Horsburgh and Horritt, 2007), consistent with storm surge behaviour but not tsunamis. There is no information on waves generated. The only indication of the height of the storm surge is from the historic indicators listed below.

Pathway

It was reported that the flood reached a speed of 48 km hr-1 and 7.6 m high; extending 6.4 km inland in north Devon, Pembrokeshire, Glamorgan, Monmouthshire and Cardiff; and up to 22.5 km in low-lying parts of Somerset (BBC, 2007). The storm surge breaches the sea wall and Burnham on Sea, Somerset (Somerset Guide, 2009).

Receptor and Consequence

This storm surge resulted in widespread and severe coastal flooding throughout southern Wales, and Devon and Somerset in England. It is estimated that 520 km2 of land was flooded (BBC, 2007). At Burnham on Sea, the storm surge broke over the sea wall and flooded 30 villages; and the surrounding countryside was flooded with 3 to 2.7 m of water (Somerset Guide, 2009). In Monmouth, it was reported that a milkmaid was rescued from drowning by ‘two lustie strong men’ who made a boat from a water trough (Whipple, 2011).

There are several indicators showing the maximum height of the water, including a chisel mark at Church of All Saints at Kingston Seymour, Somerset, that was filled with 1.5 m of water (7.74 m above sea level; Hawkins, 1982). There are several churches with commemorative plaques, perhaps the most famous of which is Marys Church at Goldcliff, Wales, where it is about 0.9 m above ground; and 7.14 m above Ordinance Datum (Williams, 1970). This plaque states: ‘On the XX day of Ianuary even as it came to pas it pleased God the flvd did flow to the edge of this same bras and in this parish theare was lost 5000 and od pounds besides XXII people was in this parrish drown’ (WalesOnline, 2013).

References

  1. Horsburgh, K. and Horritt, M., 2007. The Bristol Channel floods of 1607 – reconstruction and analysis. Weather 61 (10).
  2. Bryant, E. A. and Haslett, S. K., 2002. Was the AD1607 coastal flooding event in the Severn Estuary and Bristol Channel (UK) due to a tsunami? Archaeology in the Severn Estuary, 13, pp. 163–167.
  3. Horsburgh, K. and Horritt, M., 2007. The Bristol Channel floods of 1607 – reconstruction and analysis. Weather 61 (10).
  4. BBC, 2007. The great flood of 1607. Available at: http://www.bbc.co.uk/bristol/content/articles/2007/01/30/flood_feature.shtml [Accessed November 22 2016].
  5. Somerset Guide, 2009. Burnham on Sea. Retrieved 21 August 2014. Available at: http://www.somersetguide.co.uk/Burnham-on-Sea [Accessed November 22 2016].
  6. Whipple, T., 2011. Britain’s tsunami: ‘It will happen at some point’. The Times. Available at: http://www.thetimes.co.uk/tto/life/article2948730.ece. [Accessed November 22 2016].
  7. Hawkins, D., 1982. Avalon and Sedgemoor. pp. 29–30. ISBN 0-86299-016-5.
  8. Williams, M., 1970. The draining of the Somerset Levels. Cambridge University Press.
  9. WalesOnline, 2013. Was the great flood of 1607 Britain’s tsunami? 3 November 2013. Available at: http://www.walesonline.co.uk/news/wales-news/great-flood-1607-britains-tsunami-6265764 [Accessed November 22 2016].