Dualling of the Heads of the Valleys
12 March 2015 | 5 min read
RPS delivers multidisciplinary services for A465 Gilwern to Brynmawr road scheme, Wales.
The dualling of the A465 Heads of the Valleys road scheme is a central part of the ambitious but confident Heads of the Valleys regeneration strategy developed by the Welsh Government and five South Wales local authorities. Starting in 2006, the strategy plans to tackle root causes of economic inactivity in the region by delivering long-term effective results to improve transport infrastructure and thus accessibility and boost industry, tourism and public confidence.
The plan is to dual six sections – a 40km stretch – of this important route that connects Swansea and the M4 to the A40 and M50 route to the Midlands. A detailed schedule of works was set out in the Welsh Government's 2010 National Transport Plan. Sections One and Four of the scheme were completed in 2008 and 2004 respectively, and Section Three is currently underway – scheduled to complete in June 2015.
Section Two of the scheme, an 8.1km stretch between the Glanbaiden and Brynmawr roundabouts with a total cost in the order of £190m, was regarded as the most environmentally challenging section of the route. It has 16 major structures, over 11.5km of retaining walls and excavation of more than 1.2 million m³ of material. This section runs along the edge of the South Wales Coalfield syncline. The terrain surrounding the existing highway and proposed dual carriageway is extremely challenging for road development – with an undulating topography located in the Brecon Beacons National Park. The surrounding landscape also incorporates several internationally and nationally designated sites of environmental (Natura 2000 and SSSIs) and heritage interest. A predominant feature of the section is the protected Clydach Gorge which contains a number of Scheduled Monuments and the Mynydd Llangatwg limestone caves SSSI (protected bat roosts). The Blaenavon Industrial Landscape World Heritage Site is also close by.
In order to address these unique environmental challenges Costain chose RPS at the tender stage to lead the environmental design and assessment in the team presented to the Welsh Government. Following the award of the contract, RPS was tasked with the delivery of a comprehensive and sensitive EIA and working in close consultation with Brecon Beacons National Park Authority, Natural Resources Wales and Cadw (Welsh Government advisors on heritage). RPS produced an Environmental Statement and, in accordance with Regulation 61 of the Conservation of Habitats and Species Regulations 2010, an Assessment of Implications for European Sites (AIES) was also prepared to identify the possible impacts of the published scheme on three Special Areas of Conservation (SAC).
Thorough scoping of the required assessments was critical to delivery of the project programme. RPS’ Scoping Report set out specific environmental assessment methodologies and potential mitigation measures recommended for integration into the scheme design. Baseline data was obtained by compiling and reviewing available data and/or undertaking baseline surveys to generate site specific data. Where required, the methodology for the surveys was agreed with the relevant stakeholder.
RPS' studies included cumulative impact assessments examining multiple environmental effects on single receptors and other parts of the project using a matrix-themed approach. In order to ensure the minimum impact was visited upon surrounding sites of major environmental and historic value, RPS designed detailed mitigation measures to provide visual screening, low noise surfacing and noise barriers, and measures to compensate for the loss of bat foraging areas and a thorough Construction Environmental Management Plan. Particular consideration was also required where the road widening was proposed above the Mynydd Llangatwg caves where the route would sit between five and ten metres above the cave roofs, some of which were also bat roosts, and within 100 metres of their main entrance necessitating intricate planning for exceptionally delicate piling work.
The Environmental Statement and AIES were published alongside the Draft Orders in October 2013.
As a major multidisciplinary consultancy RPS was well placed to deliver the wide range of professional services, bringing together targeted expertise from a spectrum of dedicated resources. For A465 Section Two we assembled a team across five of our UK offices to advise on archaeology and built heritage, air quality and climate impacts, ecology and biodiversity, landscape and visual impact issues, planning services including land use and community & leisure, health impact, Habitats Regulations, geology and contaminated land matters and hydrology. RPS also appointed external specialists where specific species and/or local knowledge added value. Seven of the Welsh Government's expert witnesses at the Public Inquiry in 2014 were from RPS.
Having a long-standing relationship with Costain benefitted delivery of the scheme as our previous project experience with the contractor has established an effective understanding and methodology. This was further enhanced by the co-location of the RPS environmental coordinator with the design team and contractor in Cardiff – facilitating closer familiarity with the design process and a more hands-on accessibility to discuss and resolve environmental queries and design issues.
At the Public Inquiry in 2014 the Inspector noted the proposals as acceptable and that ‘there was an abundance of evidence to show that the scheme would comply with local, regional and National Policy for Transport and the Economy’. Although ‘Landscape and environmental policies would not all be advanced by the scheme’, both were ‘vigorously addressed’ and demonstrated ‘as part of the development of the scheme, with clear strategies to make its impact acceptable’. The strategies were noted as ‘essential in order to minimize the adverse impact on the Brecon Beacons National Park, in the Clydach Gorge and [on] the Blaenavon World Heritage Site that would otherwise occur.’
Primary construction on the A465 Section Two has recently commenced in 2015 with RPS continuing to lead the environmental work including ecological site clearance, archaeological investigations, land surveys and detailed design of landscape and environmental mitigation. The works are expected to be completed in 2018.
This case study was written for and also appears in the ENDS Environmental Consultancy Market Review 2015 which is sponsored by RPS.