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• A34 Wolvercote Viaduct Replacement

Environmental Issues

The A34 Wolvercote Viaduct is surrounded by a rich and diverse rural landscape with areas of particular value in terms of ecology and cultural heritage. We are working hard to ensure minimal impact on the local environment. The scheme will adopt a Construction Environmental Management Plan with best practice guidelines and strict codes of conduct.

Landscape

The A34 Wolvercote Viaduct is situated in the low-lying floodplain of the River Thames, which has a flat and open aspect defined by hedgerows with trees. In order to help visually screen the replacement viaduct from the surrounding area, a full landscape planting programme using native species will be implemented including the reinstatement of any vegetation that is lost during construction of the scheme.

Water Quality and Drainage

The A34 Wolvercote Viaduct is located within the River Thames floodplain in close proximity to a number of rivers, streams and lakes. The Oxford Canal flows under the viaduct and the River Thames is located to the south of the scheme.

Drainage patterns and the valuable ecological features of the floodplain are intrinsically linked and the Environment Agency is being consulted throughout the development and design process for the scheme. The scheme aims to protect the water environment via improved pollution prevention. A new drainage system has been designed to ensure that it's surface runoff enters pollution control units prior to discharging to the surrounding water bodies.

A flood risk assessment has been undertaken to assess the implications of the construction and operation of the scheme on the volume of the River Thames floodplain storage. The flood risk assessment concludes that the scheme will not increase the risk or impact of flooding both on and off site in accordance with Environment Agency requirements.

Air

Air pollutant concentrations would not exceed the National Air Quality Objectives as a result of the scheme. During construction best environmental practice will be employed for dust control and to limit odours and emissions from machinery. Traffic using the permanent viaduct will cause no significant changes to air pollutant concentrations.

Noise

The Scheme would be beneficial in terms of noise as a Quieter Road Surface would be used both on the temporary and permanent viaducts.

Cultural Heritage

The area contains a rich and diverse series of cultural heritage features, comprising a combination of archaeological and geo-archaeological deposits, historic landscapes and built heritage features. In order to mitigate impacts on the cultural heritage features present, archaeological monitoring and recording of topsoil stripping and further evaluation will be undertaken as necessary, before and during construction activities. All archaeological work would be carried out in agreement with the County Archaeologist.

In brief the cultural heritage includes:

• Wolvercote Gravel outcrops - which hold high potential for Palaeolithic (50,000 - 10,000 BC) remains including tools, plant remains and animal remains.
• The floodplain, which has the potential to contain well preserved buried archaeological remains such as those found at Oxney Mead, Port Meadow and Yarnton.
• Romano-British activity - potteries found in the area are considered to be of regional importance and are protected within the Local Council conservation policies.
• The transport system expanded in the Post Medieval period with the creation of the Oxford Canal, a number of bridges, locks and buildings. These are still retained today and contribute to the canal's overall character, including the Grade II Listed Tilting Bridge beneath the viaduct.

The condition of the Tilting Bridge will be recorded and then the bridge will be removed to a safe location, to prevent accidental damage during construction. It will be reinstated during the final stage of construction. All works to the Tilting Bridge will be undertaken in consultation with the Cherwell Conservation Officer and the British Waterways Board.

Nature Conservation

The area around Wolvercote supports a series of very sensitive and protected habitats that are largely 'wet unimproved grasslands'. In addition, important protected species have been recorded in the vicinity of the viaduct. A series of detailed ecological surveys have been undertaken to inform the design of the scheme and to identify the actions required to reduce and prevent impacts on the nature conservation interest of the area.

The scheme is designed to limit impacts on the nature conservation interest wherever possible. The Special Area of Conservation (SAC) and Sights of Special Scientific Interest (SSSIs) would not be directly affected as there will be no landtake from these designated areas to construct or operate the scheme. Mitigation has been designed to protect specific protected species. This would include relocating reptiles away from the construction area, protecting badgers and providing alternative roost areas for bats. The protection of the local biodiversity is a core consideration of the scheme.

In brief, the nature conservation interest includes:

• Oxford Meadows SAC, which includes the Pixey and Yarnton Meads SSSI, Wolvercote Meadow SSSI and Port Meadow with Wolvercote Common and Green SSSI. The site is protected by the SAC and SSSI designations as it supports the valuable 'unimproved neutral grassland' and the rare plant 'creeping marshwort', which is included in the European Habitats Directive.
• Oxford Canal Marsh County Wildlife Site, which is an area of 'wet meadow' and 'sedge dominated fen' immediately adjacent to the viaduct.
• Dukes Meadow Site of Local Interest for Nature Conservation (SLINC), which is an area of 'unimproved grassland' immediately adjacent to the viaduct.
• Bats have been recorded foraging under the viaduct with a small number of bats actually roosting in the viaduct.
• Reptiles have been found in the vicinity with three species of reptile being recorded, grass snake, slow worm and common lizard.
• Badgers have been recorded in the vicinity of the scheme.
• Invertebrates recorded in the area include 20 species of dragonfly as well as five other important terrestrial invertebrate species.