YGC’s Environment Team co-ordinated the environmental assessment to support the planning submission for the replacement of a Grade II-listed road/rail viaduct spanning the Dwyryd estuary in the Snowdonia National Park.

The structure was in poor condition, which posed a threat to the road and rail links.  The viaduct’s closure would have had a significant impact on the region’s transport network, economy and employment capability.  It was therefore decided to replace the current, inadequate provision with a modern, safe and sustainable structure.  Funding was provided by the European Regional Development Fund, Network Rail, the Welsh Government and Gwynedd Council.

Given the sensitive nature of the site and surrounding environment there was the potential for the scheme to have significant environmental effects.  Features of particular concern included:

• Pen Llŷn a’r Sarnau SAC, Morfa Harlech SSSI and the Gwaith Powdwr Nature Reserve;

• Protected species including otters, wintering/breeding birds, migratory fish, amphibians, reptiles and bats;

• Afon Dwyryd estuary;

• Local residents and commuters, and;

• The Grade II listed bridge.

We liaised closely with the Local Planning Authority and Statutory Environmental Bodies to establish the scope of the EIA and HRA.  We then co-ordinated the EIA and HRA in collaboration with technical specialists, the principal designers, environmental stakeholders and the clients within a tight programme for the outline design phase.  Ecological surveys were completed by YGC and our technical partners at appropriate times of the year.

An environmental liaison group, meeting at key intervals, was established to help environmental matters to be addressed as part of an iterative, proactive assessment and outline design programme.  Co-ordinating the requirements of the clients, designers and stakeholders was key to ensure that the needs of all interested parties were considered within the outline design.

Construction commenced in May 2013.  We utilised our site knowledge and previous experience to provide guidance and support to the client throughout the construction phase and the work was completed in July 2015.  The scheme achieved a CEEQUAL award of ‘Very Good’ in April 2016, was the CIHT’s Transportation Project of the Year and won the ICE Wales’ Innovation of the Year award for 2016.