Boscastle Floods, 2004 To compare the causes and impacts of flooding in Boscastle (2004) to Lynmouth (1952). Starter: Write down some ideas for a flood proof house. As you watch the video come up with an L/O for today’s lesson and write it down. To understand the causes and impacts of flooding in Boscastle in 2004.

The Boscastle Floods - 2004

The Boscastle flood, 16th August 2004 Boscastle is situated on the North Cornwall coast. For a hundred years the village was a thriving port but the coming of the railways soon saw its decline as a trading port. About 90% of Boscastle’s economy is now reliant on tourism. On Monday 16th August 2004 major flooding occurred in North Cornwall. The small village of Boscastle was devastated.

Causes, Effects & Responses What do these words mean? Cause – An action that makes an event happen. Effects – How people or the environment was changed in a good and bad way. Response – The help given to manage the problem.

CAUSE 1: VERY HEAVY RAIN Most of the rain fell in a five hour period Peak intensities were in excess of 30mm/hr (0.5mm per minute) A month’s rain fell in just 2 hours

CAUSE 2: THE STEEP SIDED VALLEYS The steep sided valleys that converge down to the sea, known in the trade as “flashy catchments”, act as huge funnels and can produce true flash floods after a sudden cloudburst or prolonged heavy rainfall. River Valency Bodmin Moor River Jordan

CAUSE 3: IMPERMEABLE ROCKS & CLAY SOILS The cause was the combination of intense convectional rain, local topography and the geology = resulting in a flash flood no one could have predicted.

What happened? 12.15 Rain gauge at nearby Lesnewth some 4km (2½ miles) up the valley, shows no rainfall and it is dry in Boscastle’s harbour area, yet there are torrential showers at Camelford and at the top of Boscastle.

15.30 River Valency begins to break its banks Cars swept away Cars were swept out to sea, bridges were washed away and people clung to rooftops and trees for safety as torrential rain hit the area. Emergency workers mounted a huge operation to rescue residents and holidaymakers along a 32-km (20-mile) stretch of the north Cornwall coast around Boscastle.

16.00 a 3 metre wall of water runs through Boscastle car park at 40 mph.

17.00 Rescue Helicopters. In an operation lasting from mid-afternoon until 2:30 AM, a fleet of seven helicopters rescued about 150 people clinging to trees and the roofs of buildings and cars. Amazingly, no major injuries or loss of life were reported. 55 residents were airlifted out by the Royal Air Force after the flooding, 35 BBC staff were flown in by other means.

Cause, effects and responses Which of the statements are a cause, effect or response? Explain why it a. caused the flood b. was an effect of the flood c. people responded in this way to the flood Ext: make a plan for the local council to make sure this damage does not happen again if there is a flood.

Plenary 3 things you learnt 2 things you found interesting Complete a 3, 2, 1: 3 things you learnt 2 things you found interesting 1 question you still have