£ 336 m
Construction value
Sustainability
Urbanisation
A465 Heads of the Valleys Section 2
The dualling of the A465 is a key component of the Welsh Government’s transport plans to improve access, safety and the economy in the valleys and South Wales. We have been appointed by Costain as the environmental consultants for Section 2 of the Heads of the Valleys scheme; connecting the M4 and Swansea to the A40/M50 route to the Midlands and providing an alternative route to the M4 between Newport and Swansea.
Key details
Project name
A465 Heads of the Valleys Section 2
Client
Costain on behalf of The Welsh Government
Location
Gilwern to Brynmawr, South Wales
Awards
- National Green Apple Award for Wales
- Gold Award for Environmental Best Practice at the International Green World Environment Awards (2018)
Services provided
- Environmental Impact Assessment
- Environmental coordination: design, heritage, landscape, ecology, site surveys
- Air quality
- Noise
- Public and key stakeholder consultation
- Monitoring and licencing species management
- Town Planning
- Arboriculture
- Expert witnesses for public inquiry
Challenge
Section 2 is valued at £336 million and is regarded as the most environmentally challenging section due to its location in the extremely narrow and rocky Clydach Gorge with the River Clydach running alongside. The development includes the design and construction of 14 major structures, 12.5km of retaining structures and 1.2 million m³ of earthworks whilst maintaining two-way traffic flows.
The principal environmental considerations included the site’s location within the Usk Bat Sites Special Area of Conversation (SAC) and Mynydd Llangatwg SSSI, renowned for an extensive karst limestone cave system, part of which passes under the road. Cave entrances lie in close proximity to the route and Lesser Horseshoe Bats reside in the caves and other local features of the Gorge over winter.
Solution
To address these unique and sensitive environmental challenges, we delivered a comprehensive Environmental Impact Assessment, working in close consultation with Brecon Beacons National Park Authority, Natural Resources Wales and Cadw (Welsh Government advisors on heritage).
We also undertook an Assessment of Implications on European Sites (AIES) as required as part of the Conservation of Habitats and Species Regulations 2010. Leading this assessment, we reviewed the effects of the scheme, including the additional land taken, construction and operation of the dual carriageway on the qualifying features of the SAC.
In order to protect the Lesser Horseshoe Bats, the scheme incorporated provisions including:
- An extension of existing underground bat crossings
- Acquisition of additional land in the Gorge to plant 148,000m² of woodland to mitigate bat foraging areas lost to the scheme
- The construction of a significant new maternity roost building, already showing evidence of bats using this new roost
- Erection of bat boxes and temporary screens to protect existing flight lines and connectivity to under road crossing during construction works.
Successful public local inquiry
As part of a Public Local Inquiry, we provided input and expert witnesses from five of our offices to advise on cultural heritage, air quality and climate impacts, noise, biodiversity, landscape and visual effects, land use, community and health impacts and habitats regulations.
At the Inquiry, the Inspector noted the proposals as acceptable and that there was an abundance of evidence to show that the scheme was compliant with local, regional and National Policy for Transport and the Economy. The strategies were noted as essential in order to minimise the adverse impact on the Brecon Beacons National Park that would otherwise occur.
Project timeline
2011
Tender support: design and pricing
2012-2013
Outline design, Environmental Impact Assessment and draft orders
2014
Public inquiry, inspector’s recommendations, secretary of state’s decision and confirmation of orders
2015-2021
Detailed design, construction and environmental monitoring
2022-2026
Monitoring the environmental aftercare period
Project statistics
14
Major structures developed
8 km
In length
12.5 km
Retaining structures
1.2 million m³
Earthworks
148000 m2
Woodland planted in the Gorge to mitigate bat foraging areas lost to the scheme
