New sea defence protects promenade, rail, and road

The final stage of major new sea defences designed to protect a village promenade has been completed. The project at Old Colwyn in Conwy county is also aimed at preventing the potential collapse, in extreme storm conditions, of the railway line along the north Wales coast, and parts of the A55 road. It has taken three years and about GBP35m to finish a scheme that has included the installation of 160,000 tonnes of rock armour along a 720m (2,362ft) stretch.

Conwy council cabinet member Goronwy Edwards said storms last week showed “how vulnerable some of these coastlines are”. Over many years, the level of the beach along the Colwyn Bay seafront has gradually dropped. This meant that the original sea defences and promenade had become increasingly undermined.

The huge new stone defences will be able to absorb the power of the roughest seas, protecting the promenade which, in places, is now almost 2m (6ft 6in) higher than it was originally. “It’s more like a jigsaw puzzle, not every rock will fit in a certain place,” explained Rhys Owen, who was one of those who has carefully constructed the stone groyne defences as a plant operator for contractors Griffiths.

“I think the storms we had last week just shows how vulnerable some of these coastlines are,” says Conwy councillor Goronwy Edwards [BBC] “We’ve got to design this to a certain shape, with gaps, and, of course, to get that, not every rock is going to fit,” said Mr Owen.

He and his colleagues had to battle the elements to get the job done, as well as having to follow a shift pattern dictated by tide times. The defences stretch from Porth Eirias in the west and the railway arches at the Old Colwyn end of the promenade. The improved defences further west, towards Rhos on Sea, involved the introduction of vast quantities of sand, raising the beach almost to the level of the promenade.

But modelling showed that, at the eastern end of the prom in Old Colwyn, additional sand would be washed away over time and that only a vast bank of stone groynes would provide the long-term protection needed.

“It’s more like a jigsaw puzzle, not every rock will fit in a certain place,” says Rhys Owen of contractor Griffiths [BBC] Conwy council now has plans to improve sea defences with a number of other smaller schemes at Towyn and Llanfairfechan, as well as two in Llandudno. “The coastal defence sector is key for us.

I can see it continuing to be very important,” said Owain Thomas, operations director for Griffiths.

“We’re looking to help councils and authorities invest to keep the communities that we live and work in safe.”

With sea levels predicted to rise as the effects of global warming continue, the hope is that the new defences in Colwyn Bay will prove to be as effective and long-lasting as the Victorian originals.