The Arup New Dyfi Bridge is a viaduct which spans the floodplain between Machynlleth town and Pont Felin-y-ffridd to the northeast, bypassing the vulnerable Pont ar Ddyfi road bridge. Construction spanned 2021-2023. The new viaduct is 725m long with a 74m long river span.

From the Arup website, accessed 17/01/2023:

'The A487 New Dyfi Bridge scheme involves the provision of a new 725m long viaduct across the Afon Dyfi and associated flood plain north of Machynlleth. The scheme will improve the resilience of the A487 which is the principal strategic south to north route along the west coast of Wales. It will reduce the number of closures due to flooding and the collisions with existing narrow masonry arch bridge.

Working for Alun Griffiths contractors and with Wallingford HydroSolutions Ltd, we provided technical services, including highway and bridge design, flood modelling, environmental and geotechnical engineering. The primary challenge faced by the design team was related to the impact on the river flooding and minimising any increases in flood levels.

We worked with key stakeholders such as National Resources Wales, to successfully develop a new river crossing scheme with minimum impact on flood levels. To make sure the scheme suited everyone, we led a successful Public Exhibition to engage the local community, listen to local feedback and incorporate additional works into the Scheme to maximise benefits to the community.'

Recorded during RCAHMW aerial reconnaissance.

T. Driver, RCAHMW, 17/01/2023

Site Record

A487 New Dyfi Bridge, Machynlleth