Stonehenge, Avebury and Associated Sites

• Need for information on the management (issue resolved) 
• Site Museum project (issue resolved)
• Risks of collapse of Silbury Hill (issue resolved) 
• Lack of visitor management (issue resolved) 
• Upgrading of the A303 trunk road project
• Infrastructure development pressure 
• Proposals for sections of dual carriageway and tunnel portals within the property

On 1 February 2019, the State Party submitted a report on the state of conservation, which is available at http://whc.unesco.org/en/list/373/documents. The report focuses on responding to Decision 42 COM 7B.32 and reports on the proposed upgrading of the A303 within the property, and progress made in implementing mission recommendations, as follows:

• The statutory processes for the A303 project commenced with lodgement of the Development Consent Order (DCO) application in October 2018. Extensive documentation is available at: https://infrastructure.planninginspectorate.gov.uk/projects/south-west/a303-stonehenge/?ipcsection=docs. Examination of the DCO in public is likely to run from April to October 2019, with a report by the Planning Inspectorate and a decision from the Secretary of State to follow. The land bridge at the western end of the property has been extended from 50m to 150m but the location of the eastern portal remains unchanged. The tunnel length is now 3.3km, with open cutting reduced to 800m. The State Party explored further design refinements to reduce impact on Outstanding Universal Value (OUV), including consideration of longer tunnel and land bridge options, but concluded that the increased costs of a tunnel extension at £540m cannot be justified. A longer cut-and-cover option would make little material difference to archaeological remains and, while having some beneficial effect, the additional cost is also unjustified, particularly having regard to the benefits to cost ratio, overall value for money and additional construction cost of £126m. The proposed scheme, including the western portal canopy and land-bridge, open cutting and the relocation of the current A303/A360 junction by 600m to the west of the property boundary, have all been designed to minimise noise, lighting and visibility impacts. Wider engagement with stakeholders and civil society has been achieved through the establishment of a Local Community Forum and by establishing liaison with stakeholder groups. Civil society can participate through non-statutory pre-application, statutory pre-application and DCO examination process. A ‘legacy benefits package’ including initiatives to conserve and interpret the OUV of the property will be delivered and adverse impacts of the project will be appropriately mitigated;
• There is progress with other issues including an independent and sustainable Stonehenge and Avebury World Heritage Site Trust to be established with assistance from the Heritage Lottery Fund. Funding from Highways England will support the World Heritage Site partnership with work on the Landscape Access, Sustainable Tourism and Sustainable Transport Strategies. The brief for World Heritage Property Setting Study and Boundary Review has been finalised. Techniques are being developed to address the threats posed by cultivation and burrowing animal. There is progress with planned army rebasing to the north of the property.

The State Party is pursuing statutory approval processes for the A303 Amesbury to Berwick Down project, including the proposed widening of the A303 within the property, in a timeframe, which allows for Committee Decisions to be conveyed to the relevant authorities. However, previous Committee Decisions and Advisory mission recommendations are not prominently noted in the domestic DCO application processes and readily-accessible public information.

The 2018 joint World Heritage Centre/ICOMOS Advisory mission concluded that the proposed tunnel length was not adequate to protect the OUV of the property. This conclusion is not altered by a 100m addition to the proposed land bridge at the western end. A longer tunnel section, which removes or substantially reduces the proposed dual carriageway within the property, would still be needed in order to avoid the impact on its OUV, including integrity and authenticity.

The DCO documents indicate that a longer tunnel to the west, and covering of the approximately 800m-long cutting, are both technically feasible but are not proceeding because of cost, perceived incremental benefits to OUV, and the approach taken to measuring ‘value for money’. There is also focus on measuring and aggregating impact on individual components of the property, particularly known archaeological features, and justification based on assessing whether the proposal is an improvement, rather than the best available outcome for the OUV of the property.

The State Party’s Heritage Impact Assessment (HIA) highlights that the new dual carriageway and tunnel portal in the west would adversely affect the setting of and relationships between monuments and the landscape including, amongst others, the Winterbourne Stoke Crossroads Barrows, the Diamond Group and the Normanton Down Barrows, and wider relationships between Neolithic longbarrows in and beyond these Asset Groups. The HIA also acknowledges that the scheme would introduce a deep cutting and tunnel portal between the Winterbourne Stoke Crossroads Barrows and the Diamond Group, affecting the integrity of physical relationships between the monuments. Indeed, commenting on integrity, the HIA observes that in the areas where the road is not in a tunnel, there would be stretches of new dual carriageway, much of it in cutting; although the extent of these sections of dual carriageway is limited to 800m in the western approach (when the canopy and Green Bridge Four are taken into consideration) and 300m in the eastern approach (when the canopy is taken into consideration). The construction of the cuttings and the portals would require permanent change and would have an adverse impact on the OUV of the World Heritage property. The development of new areas of dual carriageway and portals, particularly in the western approach section, would introduce additional adverse impacts and degrade the integrity of the property.

The current scheme includes design refinements, which address matters such as noise, lighting and general visual appearance. Extending the covered section of the western part of the tunnel and adding a land bridge are improvements, as is the removal of the link between Byways 11 and 12. However, consistent with the findings of the 2018 mission, further substantive changes are required at the western end of the proposed tunnel, noting that the 2018 mission acknowledged that the eastern portal has been optimally sited and designed. It remains preferable that the tunnel itself be extended so that the portal is located completely outside the western boundary. Clearly, this presents technical challenges, but it is possible. The information provided by the State Party costs this change at £540m. If this does not occur, an alternative would be to cover the proposed cutting within the property, which the State Party costs at an extra £126m.

While the design refinements and proposed legacy benefits are welcome, the State Party and its agencies should again be urged to ensure that the best available solution is identified and implemented for the upgrading of the A303.