Mountain Ash (A4059)
The Council has recently completed targeted Resilient Roads schemes on two key commuter routes – the A4059 at Mountain Ash and the A4058 at Dinas – which are designed to reduce the risk of highway flooding in heavy rainfall.
The schemes were completed ahead of schedule in the early weeks of March 2025, having each received a 90% contribution from Welsh Government’s Resilient Roads Fund – with the remaining funding met by the Council’s Highways and Transportation Capital Programme for 2024/25. The work was predominantly completed while maintaining two-way traffic flow, with traffic lights only used outside of peak travel times for necessary works in the road.
The A4059 scheme at Mountain Ash, which started in mid-January 2025, represents phase two of the planned work – and has installed a new culvert and associated inspection chambers. It has targeted a specific issue of rainwater running off the mountain and collecting within the highway. The new culvert will direct rainwater to the existing swale, which is adjacent to the road.
The Dinas scheme, which started in early February 2025, aims to tackle surface water accumulations where A4058 Cymmer Road meets Appletree Road, following several flood incidents impacting 11 properties since 2012. Extra gullies have been installed to divert the highway drainage through a new carrier line down Appletree Road, connecting with a separate carrier line and discharging to the river. Flood risk is also reduced to Welsh Water’s combined sewer nearby, having disconnected the highway drainage along the A4058.
A spokesperson for Rhondda Cynon Taf Council said: “These important Resilient Roads schemes at Mountain Ash and Dinas are complete ahead of schedule, and are aimed at diverting water away from the highway in periods of heavy rainfall. Each scheme tackles known issues of water accumulating on the carriageway, at key locations on two of our busiest commuter routes, and we have welcomed Welsh Government’s support towards their delivery.
“The Resilient Roads Fund is one of the funding avenues available to the Council to deliver local flood alleviation work, and it enables us to target key locations on the highway network with a history of flooding. While many of the 2024/25 schemes will be completed by the end of March 2025, the Council has bid for funding support for a further 18 Resilient Roads schemes in the 2025/26 financial year, which are collectively valued at £3.1 million.
“Storm Bert in November 2024 was another reminder that storm events are becoming more frequent due to climate change. We’ve invested more than £100 million in flood alleviation schemes since 2020, to help protect local households, businesses and infrastructure. Storm Bert suggested that the work we’ve done to date has been largely effective, but we also acknowledge that there is a lot more to be done in Rhondda Cynon Taf communities.
“Alongside our 2025/26 Highways Capital Programme and Resilient Roads Fund grant bids, we’ve submitted funding requests to Welsh Government to further develop 15 larger flood alleviation schemes and 13 small scale schemes. If all our bids are successful, it would represent further funding of £6.1 million.
“Thanks to the local residents and road users in Mountain Ash and Dinas for their cooperation during the recently-completed Resilient Roads schemes – which were also completed without needing significant traffic management.”
Posted on 20/03/2025