Flood maps show how Llandudno could be sea-swamped without swift action

Kashmiri goats gaze down on Llandudno from the Great Orme
-Credit: (Image: Karl Eastwood)


Work on Llandudno’s upgraded sea defences will start later this year, once the summer season is over, Conwy Council has confirmed. The resort’s vulnerability to flooding has long been recognised but agreeing the designs for new protections has taken the best part of a decade.

The process became mired in public debate over the loss of sand from North Shore beach and the unwillingness of the Welsh Government to fund its replacement. Fearful at the potential loss of central funding, the local authority opted for a non-sand option.

At the eleventh hour, in order to make the most of funding available, the council brought forward plans for a sea wall that analysts predicted wouldn’t be needed for several decades. New maps were used to inform this decision and these show that the threat of flooding remains very real.

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They suggest that, over the coming decades, residents may be grateful a new North Shore set-back sea wall was built ahead of schedule. For many, however, it will never fully compensate for the loss of an iconic sand and shingle beach that did so much to establish Llandudno as one of Britain’s premier seaside resorts. Critics have pledged to fight on.

To inform the design of the new flood defences, Conwy Council’s flood modelling specialists HR Wallingford produced updated flood maps. These enabled engineers to better understand how the town might be impacted by coastal flooding from rising sea levels and increased frequency of storms.

In reality, these merely refined what everyone knew: that low-lying Llandudno is at risk of being swamped from the sea. Even if existing defences are properly maintained, a freak, one-in-200-year storm could leave much of the town underwater and come within 400ft of turning the Great Orme into an island.

Climate projections predict that sea levels along the Conwy coastline will rise between 0.9-1.2 metres by 2120. Modelling indicates that current North Shore defences are more liable to overtopping than those on the West Shore. The North Wales Live Whatsapp community for top stories and breaking news is live now - here’s how to sign up

The great flood of 1993 left Llandudno with severe flooding. It was caused by a combination of heavy rain, a high tide and antiquated sewers
The great flood of 1993 left Llandudno with severe flooding. It was caused by a combination of heavy rain, a high tide and antiquated sewers -Credit:North Wales Live

The latter's defences were upgraded in the 1950s, when a new wave-return wall was built and rock armour was dumped over stone steps on which visitors were fond of perching. Largely, it’s done its job ever since.

Before then, West Shore was vulnerable to the kind of incursions now being envisaged in the future. “In the 1920s the area used to flood quite frequently,” said one resident online. “I remember my mother saying that the water travelled down Gloddaeth Avenue and nearly met with flood water from the North Shore.”

Even a one-in-50-year storm is forecast to cause significant flooding from the North Shore, especially if the current sea wall is not maintained properly (light blue)
Even a one-in-50-year storm is forecast to cause significant flooding from the North Shore, especially if the current sea wall is not maintained properly (light blue) -Credit:Conwy Council
Flood modelling for the North Shore, showing the impacts of a one in 200-year flood in two scenarios - walkway and do nothing, or continue to maintain existing defences
Flood modelling for the North Shore, showing the impacts of a one in 200-year flood in two scenarios - walkway and do nothing, or continue to maintain existing defences -Credit:Conwy Council

The latest flood maps showed that the current flood defences on North Shore, if properly maintained, should prevent widespread flooding in a one-in-50-year storm - though over-topping was still possible in some areas, especially near the new RNLI station. However a more powerful storm (one-in-200-years) would wreak devastation on the resort. So too would a lesser, more likely storm if the defences were allowed to fall into disrepair.

In contrast, the maps indicated that, were the council to “walk away” from the West Shore defences – stop all maintenance and let them fall into disrepair – they would continue to perform almost as well. In the event of a one-in-50-year storm, water could overtop the defences near Dale Road car park and flow into residential areas.

A “bigger but less likely" storm (0.5% chance) would cause more significant inundation of properties. Sign up for the North Wales Live newsletter sent twice daily to your inbox

Last December, Conwy Council tendered for the work to build the latest set of defences. This stated the project would involve: “The construction of two new walls, one 300mm in height and 50 metres in length, one 500mm in height and 80 metres in length; the construction of a pedestrian access ramp; the provision of minimum 2 new flood gates; the construction of new access points in existing walls; the construction of 14 no supports for timber flood barriers; the reprofiling of existing beach material (NO importation of new material); and various public realm improvements.”

West Shore flood modelling, showing the impacts of a one in 50-year flood in two scenarios
West Shore flood modelling, showing the impacts of a one in 50-year flood in two scenarios -Credit:Conwy Council
How a one-in-200-year flood might overtop the current West Shore defences in two scenarios
How a one-in-200-year flood might overtop the current West Shore defences in two scenarios -Credit:Conwy Council

Subsequently, the Welsh Government approved the council’s revised business case for coastal defence works costing up to £5.2m. These, said the local authority, would address “known weak points” in the current defence system and stop it being “outflanked” during storms. The project would be 85% funded by Cardiff and the rest by Conwy.

At the time, a spokesperson said: “The work includes strengthening the existing 1.8km seawall at North Shore promenade, as well as extending the low-level seawall by 200 metres in length and constructing a new flood gate at the eastern end of the promenade.

“At West Shore, a 45-metre length of new seawall will be constructed, as well as modifications and repairs to the existing seawall and highway to reduce the potential of flooding in a significant coastal storm event.” The work, said the council, would help safeguard up to 4,982 homes and 1,056 commercial properties considered at risk of coastal flooding in the next 50 years.

The modified defences are designed to give protection against a one-in-200-year storm. By choosing to build a new set-back wall now, instead of in 2070 as originally planned, the level of protection will be “significantly higher”, said Huw Irranca-Davies, minister for climate change & rural affairs. It will also guard against future sea level rises, he added.

A council spokesperson said: “A public information event will be held in the next few months for residents and businesses. We aim to be ready to start work on building the improved flood defences later in 2024.”

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