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We have built a new section of the A487 north of Machynlleth, including a new bridge across the River Dyfi.

Region / County:
Start date:
spring 2021
End date:
January 2024
£46 million (costs under review in light of inflation pressures)
First published:
31 July 2018
Last updated:


Why we did it

The Pont-ar-Ddyfi bridge is over 200 years old, and was not designed to carry the current volume of traffic. The road is often closed due to frequent flooding, forcing drivers to take a diversion of up to 30 miles.

We wanted to:

  • make it easier to cross the River Dyfi
  • make it easier to access jobs, healthcare and education
  • make sure  people can still access Machynlleth even when there is heavy rain and flooding
  • make the A487 safer
  • help prevent flooding
  • make it easier for people to walk,cycle and wheel across the bridge.

What we did

We built a new 1.2km single carriageway road joining the existing A487 south east of Pont-ar-Ddyfi bridge.

The new road crosses the River Dyfi approximately 480m upstream of the existing bridge. 

The existing A487 south of the Pont-ar-Ddyfi bridge is no longer a Welsh Government road and will be maintained by local authorities.

Building work started in spring 2021, and comprised:

  • 1.2km single carriageway road starting at the northern edge of Machynlleth, crossing the Afon Dyfi flood plain, and re-joins the A487 to the south
  • 2.5m wide shared use active travel link over the New Dyfi Bridge 
  • flood bunds to protect the Dyfi Eco Park and road under railway
  • emergency surface water pumping facilities which will limit flood water under the railway and Dyfi Cottages
  • landscaping works / tree planting
  • utility service diversions preparations (e.g. gas, water, electric, broadband/phone lines etc.)
  • all concrete and steelwork structure elements of the bridge.

Aerial view of the works to build the new Dyfi bridge:

Next steps

Between now and summer 2024, we will:

  • complete drainage improvement works in front of Dyfi Cottages. This will require the closure of the A493 to all vehicle traffic so the work can be carried out safely. The closure is planned for 10 February and will last up to 30 days
  • work with partners to further enhance active travel facilities towards Machynlleth / train station
  • complete next phase of landscaping / tree planting works including returning the land under the viaduct to green fields
  • carry out maintenance works on the old road before it’s transferred to the local authority to maintain and look after (up to four months work in spring 2024)
Photograph showing work nearing completion on the Dyfi bridge. Scene is frosty with clear skies.


Reports, environmental statements and plans

Help and support

Ask a question about the project or report an issue

Find out more

If you have any concerns or questions, contact the public liaison officer on 0330 041 4651. Croesawir galwadau yn Gymraeg / calls are welcomed in Welsh.