RED MENACE
Areas that may be under water within a decade
ALARMING maps have revealed the parts of North Wales which could be underwater in less than 10 years.
Huge swaths of coastline are threatened by rising sea levels and flooding as early as 2030.
The maps are projections based on the “current trajectory” of climate change.
Even if this month’s COP26 climate change conference in Glasgow results in sweeping and immediate cuts to carbon emissions, several areas in North Wales will still be vulnerable to sea flooding.
They include Glaslyn estuary near Porthmadog, plus coastal areas near Pwllheli and low-lying land around Shell Island in Gwynedd.
Without further climate mitigation, huge swaths of the North Wales coast could periodically find themselves under water within nine years.
Earlier this year, oceanographers at Bangor University warned rising sea levels could cut off the A55 and wash away the North Wales Coast railway by the end of this century.
Important economic infrastructure, such as Deeside Industrial Estate, and several Snowdonia holiday resorts, could also be swamped.
However Climate Central, a non-profit news organisation focused on climate science, now claims the risk of flooding could be three times higher than previously forecast.
It has used advanced models of coastal elevations and peer-reviewed projections for future flood levels to map areas forecast to be most vulnerable to coastal flooding and storm surges.
While Climate Central warns there is always some margin for error, the maps “should be regarded as screening tools to identify places that may require deeper investigation of risk”.
NORTH WALES COAST
This stretch of coastline is already defended, with plans to increase its resilience to flooding.
One flaw of the Climate Central maps is the absence of data for existing or planned sea walls. The result is an amplified projection of future flooding.
At greatest threat is land west of the River Clwyd. At Pensarn and beyond, Climate Central expects annual flooding to be affecting the A55 within nine years.
LLANDUDNO AND THE
CONWY VALLEY
Ever since marshlands fronting Llandudno Bay were redeveloped as a holiday resort in the 19th century, the potential for flooding has always been an issue.
Latest plans include new timber groynes to stop beach erosion.
It’s one of several flood defence schemes in various states of progress in Conwy county: others include a 300ft breakwater in Penrhyn Bay, a raised beach and one-way promenade at Rhos on Sea and a phased approach in Colwyn Bay as funding becomes available.
Along the estuary, reclaimed farmland in the Conwy Valley is already used as flood over-spills. By 2030, Climate Central expects this to become an annual occurrence, with the swollen waters affecting parts of Llanrwst.
ANGLESEY
Malltraeth Marsh, stretching from Anglesey’s western coast beyond Llangristiolus and the A55, was reclaimed from estuarine marshland in the early 19th century.
After the construction of Malltraeth Cob, Afon Cefni was canalised in 1824 and it became possible to grow crops on the land.
The system required constant maintenance, and by the Second World War it had fallen into disrepair, devastating postwar harvests. Although the area’s network of embankments was subsequently improved, farmers are again witnessing more frequent incursions.
By 2030, Climate Central predicts the entire marsh will be at risk of annual inundation.
Low-lying land east of the marsh is not under immediate threat. However longer-term projections, based on runaway climate change, suggest the entire island could be cut in two.
MID GWYNEDD AND THE LLŶN PENINSULA
This wide, flat valley of Traeth Mawr was once the Glaslyn estuary before the Porthmadog Cob was built.
Effectively, this sealed off the estuary’s mouth, enabling the land to be reclaimed for farming.
As sea levels rise, this land is under threat of abandonment. Already, some local farmers complain that previously oncea-century floods have become a regular occurrence.
Low-lying land towards Harlech and down to Llanbedr is also coloured red in Climate Central’s 2030 maps, indicating annual flooding within nine years.
Further south, beyond Barmouth, lies Fairbourne, one of the cause celebres of the climate debate.
Originally salt marshes, it’s defended by a sea wall that is becoming unsustainable.
Fairbourne is expected to be abandoned between 2052 and 2062 – or as early as 2042 if the seas rise faster than the 0.5 metres currently predicted.
DYFI ESTUARY
The estuary has extensive salt marshes with a network of mudflats and river channels. As such, it has been designated a Special Protection Area for wild birds, with large numbers attracted to its feeding grounds.
On its western flank, RSPB Cymru runs the Ynys-hir reserve.
Much of this, and the sand dunes of Ynyslas, could find itself under water at least once a year by 2030, according to Climate Central’s projections.