‘A chance in any year’: Denbighshire can expect more flooding in future warns climate report after 2020 evacuations

Richard Evans, local democracy reporter

Residents in Denbighshire can expect more floods as the planet heats up, a report has said.

Storm Ciara hit the north of Wales on 9 February 2020, causing residents across Denbighshire to evacuate their homes.

The storm caused raging winds reaching well over 90 mph, with some of the country’s highest rainfall falling over the north of Wales.

The flooding was concentrated around the River Elwy, the River Ceidiog, the River Ystrad and the River Clwyd, affecting St Asaph, Llandrillo, Brookhouse (Denbigh) and Llanynys.

Residents had to abandon their flooded houses whilst some homes in isolated rural villages also became uninhabitable.

The flood and management water act requires councils to investigate flooding and publish its findings. This morning (Tuesday) Denbighshire County Council councillors gave their feedback on the comprehensive 185-page report compiled by council officers, Welsh Water and Natural Resources Wales.

Keith Ivens from Natural Resources Wales took questions from councillors. Mr Ivens said the recently improved river defences at St Asaph were good but had failed due to ‘an extreme event’ causing ‘topping’. He called the storm a one-in-200-year event.

“The community of St Asaph has a very good standard of protection. It protects 370 properties that would have flooded otherwise, and the event we saw in Storm Ciara was in excess of the design standards it was designed to protect against,” he said.

“So we can’t protect against all events.”

‘Frequency’

Keith Ivens was also asked about the failure of a water-level recorder warning system under the A55 at St Asaph.

He replied: “So that did fail at the top end. The type of equipment installed there is something called a pressure transducer, and they are set with an upper and lower limit, and what happened was it exceeded the upper limit of the pressure transducer. That has now been replaced.

“Well, that is still in place, but an additional downward-facing ultrasonic level sensor is actually situated on the new Spring Gardens Bridge. So we’ve got an additional sensor there that allows us to monitor water levels if we need to, and that also feeds into the flood forecasting model we have for the Elwy.”

The report recommends the council undertakes a performance review for its St Asaph flood risk management scheme; reviews its flood map data for the Wigfair Isaf community; works with landowners at Afon Elwy and addresses resilience shortfalls.

But Mr Ivens warned of future flooding: “There is always a chance of it (a severe storm) happening in any year. What we are seeing is that with climate change the frequency in which these larger events are happening does seem to be (increasing).”

Councillors voted in favour of supporting the report. You can read the entire report, including the full list of recommendations, here.