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 4 February 2020, the State Party submitted a report on the state of conservation, available at http://whc.unesco.org/en/list/373/documents. Subsequently, updated information was provided by the State Party in relation to the decision-making process of the A303 scheme. The report focuses on the Development Consent Order (DCO) planning process for the proposed A303 road improvement scheme, at Stonehenge, which includes:

• a 3.3 km long tunnel, with cut-and-cover canopy at eastern and western portals;
• a c. 150m-wide ‘green bridge’ south of the Winterbourne Stoke Barrow Group;
• a deep cutting, approximately 1km, with vertical retaining walls containing the dual carriageway western approach roads; and
• a new flyover junction of the A303 with the A360, 600 metres west of the existing Longbarrow roundabout and the Winterbourne Stoke Barrow Group (on the western boundary of the property).

In response to Decision 42 COM 7B.32, consideration was given to extending the bored tunnel and to greater covering of the cutting, but it was determined that the additional benefits would not justify the costs. The decision was instrumental in securing additional mitigation measures, including the c. 150m ‘green bridge’. A detailed Archaeological Mitigation Strategy has been finalized to guide archaeological mitigation associated with the design and construction of the proposed road improvement.

Public Planning Hearings took place between April and October 2019. 16 hearings were conducted; two specifically directed at cultural heritage and with most of the rest also considering aspects of heritage. Decision 43 COM 7B.95 was relayed to all key parties to the hearings. The additional small-scale detailed design and mitigation measures aimed at reducing harm to the Outstanding Universal Value (OUV), were also presented to the hearings.

The Planning Inspectorate reported their Recommendations to the Secretary of State for Transport on 2 January 2020. The decision-making deadline for the A303 improvement scheme was initially postponed from early April to 17 July 2020, then to 13 November 2020, in order to consult further on recent archaeological finds. The Secretary of State approved the Development Consent Order (DCO) in November 2020. Subsequently, a request for judicial review of the DCO decision was lodged with the High Court, which will likely be considered in June 2021.

The State Party has offered to discuss an appropriate measure of ongoing engagement with the Committee, the World Heritage Centre, and ICOMOS. Legally binding safeguards are proposed to ensure that heritage advice and considerations will contribute to construction, operations and maintenance.

Details are also provided on other initiatives and projects, including a forthcoming property setting study and related boundary review, and plans for implementing the 2015 Transport Strategy at the Avebury component of the property.

Progress with new management and governance arrangements, implementation of an improved Transport Strategy for Avebury, introduction of Traffic Regulation Order and the proposed study of the property’s setting are welcome. The setting study should be submitted to the World Heritage Centre for Technical Review by ICOMOS (noting the potential for ensuing changes to the boundary of the property).

Although consideration was given to extending the length of the bored tunnel across the property proposed as part of the A303 dual carriageway road upgrade, and to greater covering of the approach road cutting, as recommended by the Committee, the State Party determined that the additional landscape benefits would not justify the additional costs. Although small-scale design refinements that seek to reduce impact on the OUV have been made, such as a c. 150m ‘green bridge’ to the west of the proposed tunnel, the overall position with the proposed A303 improvement scheme has not changed substantively while the State Party has pursued the applicable national statutory planning process. The proposed tunnel still only extends across part of the property, with around 1km of the proposed new dual carriageway being exposed in a wide cutting within the open landscape.

The proposed tunnel length remains inadequate to protect the OUV of the property. As both the 2018 World Heritage Centre/ICOMOS Advisory mission and, subsequently, the Committee have advised, a longer tunnel section, which removes or substantially reduces the proposed open dual carriageway approach to the tunnel within the property, and is required in order to avoid highly adverse and irreversible impact on OUV, particularly on the integrity of the property. It is regretted that for such an iconic World Heritage property, the argument persists that the perceived benefits of a longer tunnel do not outweigh the costs. Additionally, the approach to propose mitigation measures for the adverse impacts of the planned A303 scheme could not be considered an appropriate solution. Notwithstanding the approval of the DCO, the scheme should be modified to deliver the best available outcome for the OUV of the property.

The Committee has previously been advised that the State Party’s own Heritage Impact Assessment (HIA) highlights that the current proposal 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. The HIA also acknowledges that the scheme would impact on the integrity of the intended spatial relationships between monuments, a key part of the prehistoric ‘landscape without parallel’ as inscribed.

While it is noted that the State Party is committed to engage further, if the permission which has been granted were to be upheld by the High Court, it is unclear what might be achieved by further engagement, as it would not be possible to compensate for the unacceptable adverse impacts of the present scheme, which the State Party itself has identified, and which are borne out by the findings of the 2018 mission.

The approved A303 improvement scheme threatens the integrity of the property within the meaning of Paragraph 179(b) of the Operational Guidelines. It is therefore, recommended that the Committee consider the inscription of the property on the List of World Heritage in Danger in the event that DCO consent was confirmed by the High Court. Such a decision would exacerbate this threat.