The Flood Risk Problem

• 757 properties at 1 in 100 annual chance of flooding
in any given year.
•The main problem is coastal flooding – this scheme
aims to reduce risk of flooding from the sea
•It is common see overtopping at the north-most end
of the promenade in relatively “normal” conditions,
i.e. median level tides, without surge, swell, low
pressure or high winds.
• During the January 2014 storm, significant damge
was caused affecting both North and South Barmouth,
including the Promenade Cafe
•Increased risk of overtopping due to deteriorating asset
condition and climate change causing sea level rise
and increased storminess (this means higher waves at
increased frequency, more frequent and intense storms)
• 2 watercourses discharge to the sea via a pumped
surface water system and separate screened culvert.

The Flood Risk Problem: Condition

 The deteriorating condition of some coastal defences
increases risk of flooding from the sea and is likely to
worsen surface water flooding.
• The structural elements of the defences (e.g. Timber
groynes, primary wall and revetment, steel sheet piles, and
secondary flood wall) have varying remaining life spans.
Some elements need continual repairs or improvement and
without these are at risk of failure.
• Exposed steel sheet piles have corroded, thinning and
forming holes, creating a pathway for the sea to wash out
material beneath the promenade.
• There are signs of undermining beneath the promenade and
ground radar survey results indicate potential voiding and wash
out of fill material in the north.
• Without additional investment there is likely to be
further voiding, weakening the frontage
structures.
• For example, the March 2020 storm caused
collapse of North promenade due to voiding.
• Access points to the beach are in poor condition
and groynes restrict mobility along the beach,
increasing risk of entrapment at high tide