Storm Ashley brings sea flooding to Welsh coastal communities

Storm Ashley brought heavy rain and very strong winds across Wales on 20 and 21 October 2024, mostly affecting coastal areas and communities, according to Natural Resources Wales (NRW) in its flood risk management annual report for 2024/25¹. NRW records that sea flooding was experienced around the coast, including in the coastal communities of Borth, Amroth and Aberystwyth¹. The report describes Ashley as the first storm of the 2024/25 storm season².

The annual report covers the financial year from April 2024 to March 2025 and sets out the storms NRW responded to in Wales¹. It records seven named storms in the financial year covered². The same report gives the wider context for coastal risk in Wales: NRW estimates there are 275,000 properties at risk of flooding in Wales, approximately 1 in 7 properties, and states that as of April 2025 the undefended sum of properties at risk of flooding in Wales is 342,436¹. Removing double or triple counting of properties at risk from multiple sources, it puts the figure at over 274,000 properties¹.

The report also sets out projections for coastal risk. It states there are predicted to be over 131,000 properties at risk of flooding from the sea by 2120, an increase of nearly 40,000 from the present day, alongside nearly 131,000 properties at risk from rivers and over 48,000 more at risk from surface water and small streams².

The report also records the warning arrangements in place during the year. NRW's new Flood Warning Information Services for Wales went live on 17 July 2024, part of a £5m multi-year project that replaced the previous flood warning system¹. NRW describes the new service as decoupling it from the previous England and Wales service and allowing it to better respond to the needs of customers in Wales in the future¹. The report adds that work advanced on a project to replace the ageing Telemetry system, due for roll out later in 2025¹.

Why it matters for households

For households on the Welsh coast, the report confirms that sea flooding reached communities at Borth, Amroth and Aberystwyth during Storm Ashley, and that coastal areas bore the brunt of the storm¹. NRW's figures indicate that coastal flood risk is not fixed: it projects over 131,000 properties at risk from the sea by 2120, nearly 40,000 more than at present². The report states that flood risks are increasing and that it is not a static concept¹. NRW's flood warnings for Wales are issued through the Flood Warning Information Services for Wales, live since 17 July 2024¹. The report does not give property-level detail for Borth, Amroth or Aberystwyth, and no casualty figures for Storm Ashley are reported in it.

What happens next

The report records that the Welsh Government published a revised planning policy, TAN15: Development, Flooding and Coastal Erosion, on 31st March 2025¹. NRW released an updated Communities at Risk Register in January 2025, alongside a Climate Change Communities at Risk Register for the first time¹. The replacement Telemetry system is due for roll out later in 2025¹. The report is based on information available in spring/summer 2025¹.

Households can read more on coastal flooding, tidal surges and erosion, on flood alerts, flood warnings and severe flood warnings and on Wales: Natural Resources Wales warnings and risk maps.