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Tides
are produced by the movement of the sun and moon and follow a natural
cycle, with higher 'spring' tides occurring every 14 days. These
spring tides are particularly high at the spring and autumn equinoxes.
Tides
can be predicted long in advance and are published in tide tables.
However the actual tide level each day varies according to weather
conditions. Low pressure causes water levels to rise. In bad weather
this can build up into what is known as a storm surge.
While
storm surges occur several times a year, it is rare for conditions
to be severe enough to cause significant flooding. Serious tidal
flooding has occurred three times in the last 50 years.
The
worst incident in living memory was in January 1953 when a storm
surge, combined with a high spring tide, devastated communities
in five counties along the east coast. 307 people lost their lives.
In
1978 a surge caused extensive flooding along the North Norfolk coast
and in 1990 in Towyn, North Wales, a storm surge of 1.5 metres breached
defences and rapidly flooded the town.
Some
areas of the coastline are sensitive to tides alone whereas others
are exposed to the additional force of waves.
Waves
are produced by strong winds blowing across the sea and can cause
serious damage to natural beaches and coastal defences.
Incidents
like this can and do happen. It is important to be prepared.
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