NON-TECHNICAL SUMMARY 1. Project Background 2. Proposed Scheme Description 3. Environmental Impact Assessment (EIA) 4. Review and Comments  


1. Project Background

1.1. Introduction

The Scottish Government (Transport Scotland) is proposing to replace Ba Bridge on Rannoch Moor (Figure 1.1) as it is under strength having been found to fail the minimum load carrying capacity for Trunk Roads. The bridge over the River Ba is located within Rannoch Moor Site of Special Scientific Interest (SSSI), Rannoch Moor Special Area of Conservation (SAC), Ben Nevis and Glen Coe National Scenic Area (NSA) and neighbours Rannoch Lochs Special Protection Area (SPA). The bridge carries the single carriageway A82 Trunk Road over the River Ba.

Figure 1.1 The western side of the existing Ba Bridge.

Figure 1.1 The western side of the existing Ba Bridge.

This scheme was formerly being developed by Jacobs Babtie on behalf of BEAR Scotland to undertake the due processes required by the ‘Environmental Impact Assessment (Scotland) Regulations1999’. The scheme is now being developed and completed on behalf of Transport Scotland by Scotland TranServ who took over the North West Contract to maintain and upgrade the Trunk Roads in 2006. The Environmental Statement (ES) identifies the existing (baseline) environmental conditions and presents a variety of measures to prevent or reduce the predicted impacts. These are known as mitigation measures.

The Non-Technical Summary (NTS) is designed to provide an accessible summary of the ES and includes a brief description of the development proposals, the key potential environmental impacts and proposed mitigation measures.

1.2. Existing Bridge

Forming part of the A82, Ba Bridge is a three span bridge with parapets of coursed masonry, supported on masonry-faced concrete piers and abutments. It stands at a height of approximately 2.5 metres above the river level (Figure 1.1). An inspection concluded that the existing bridge structure was under strength and in need of repair to comply with British structural requirements for trunk roads.

2. Proposed Scheme Description

2.1. Scheme overview

The scheme proposal is to replace the existing Bridge with a design that is both stronger and wider. The new bridge will be placed on the existing alignment but it will be of a different design. The new bridge will cross the watercourse in three spans using the two existing intermediate piers as central supports. These shall be lowered by approximately 1 m. New reinforced concrete abutments shall be constructed behind the existing masonry abutments to minimise construction activity adjacent to the watercourse.

Throughout construction, traffic flow will be maintained on a temporary bridge, erected immediately to the west of the existing bridge. The temporary bridge will accommodate one lane of traffic that will be subject to appropriate traffic management to allow traffic flow in both directions. Upon completion the traffic will be moved onto the new structure, allowing the removal of the temporary bridge.

As the new deck is to be wider than the existing one 2.5 m high by 5 m long reinforced concrete retaining walls are to be provided at the bridge corners. It may be necessary to extend the works slightly beyond the existing footprint in order to accommodate the carriageway cross-section. Provision for pedestrians shall be made on the temporary bridge and maintained throughout the construction phase. On completion of the scheme peat turves removed in the area of the temporary bridge will be replaced and the area shall be reinstated to its existing condition using local provenance seed mixes.

2.2. Construction

2.2.1. Construction programme

The new bridge will be constructed by tendered contractors. It is anticipated that the construction works will be completed in stages as outlined in Table 2.1

Table 2.1 Key construction stages

Stage No.

Stage Description


Site compound establishment


Construction of substructure and foundations of temporary bridge


Construction and opening of temporary bridge


Removal of existing Ba Bridge


Construction of new bridge


Removal of temporary bridge


Landscape works


Removal of site compound

During construction, materials and the site compound will be located in a lay-by on the northbound carriageway, approximately 150 m north of the bridge and also at an informal lay-by directly opposite this on the southbound carriageway. The contractor will be permitted to work within normal construction hours from 0700 hours to 1900 hours during the summer months and may be less in winter, seven days a week for a period of 10-12 months. Night time working will be kept to a minimum in order to prevent disturbance to sensitive nocturnal species such as otter and bat. Throughout the construction works, mitigation measures will be put in place to ensure that impacts on the local environment are minimised.

2.2.2. Traffic management and access

Traffic management measures will be required during the construction period. A number of operations will require use of one-way traffic management and it is likely that this will be constant throughout the construction period.

Pedestrian access will be provided throughout the duration of the programme although there may be short periods when access is restricted and pedestrians may need to be escorted through the site.

2.2.3. Options appraisal

A report produced by Babtie in June 2002 ("Rannoch Moor/Glen Coe Assessment Review/Options Appraisal") considered the available options following a bridge failing to meet the BD21 Standards for Trunk Road bridges. These options were propping, strengthening, repair or closure. Propping is considered as a temporary measure in advance of strengthening, repair or replacement. The report compared and considered the advantages and disadvantages of various strengthening and replacement options. Subsequently, discussions with both BEAR and the Scottish Executive concluded that, on a value for money basis, the preferable solution was to replace the bridge. This is in recognition of the fact that, while there is an additional capital cost associated with the construction of a new structure, there are significant long-term benefits, including reduced maintenance costs.

The option presented in this ES was considered to be the preferred option, taking into account technical, economic, environmental and stakeholder considerations.

3. Environmental Impact Assessment (EIA)

3.1. Consultation

As part of the EIA process, a comprehensive consultation exercise was carried out with both statutory and non-statutory organisations. A total of 33 organisations were invited to comment and submit relevant information concerning the scheme and subsequent proposals. This exercise assisted in the identification of possible environmental impacts and the selection of appropriate study methods and mitigation measures, focussing on the most important, site specific environmental issues.

3.2. Scoping

All of the receptors with potential to be impacted as a result of the scheme were considered during the scoping stage of assessment. As a result of scoping some of these were "scoped out" from further assessment and are therefore not considered in this environmental statement. This process is summarised in Table 3.1.

Table 3.1 Summary of the issues scoped in and out


Scoping of Issue for Further Assessment

Reason for scoping in/out

Land use


No significant impacts to land use.

Geology and soils


Small area of disturbance to substrate and geological resources.

Water quality and hydrogeology


Bridge crosses a sensitive water course.

Ecology and nature conservation


Surrounding area is of high natural heritage value.



New elements will be introduced to sensitive area.

Visual issues


New elements will be introduced to sensitive area.

Cultural heritage


Unrecorded archaeological features are unlikely to be found on site because the area would have been heavily disturbed during the original construction of the A82 and Ba Bridge. This has been confirmed through consultation.

Air quality


The scheme will not result in a change in traffic conditions on the bridge during the operational phase, so no increase in air pollution is anticipated.

Traffic noise and vibration


The scheme will not result in a change in traffic conditions on the bridge during the operational phase, so no increase in noise or vibration is expected, thus no impact to the nearest receptor, which is five miles away.

Pedestrians, cyclists and community effects


The scheme will improve the situation for pedestrians and cyclists by the inclusion of a footway and wider bridge.

Vehicle travellers


On-line bridge replacement.

Disruption due to Construction


10 – 12 month construction in sensitive area.

Policies and Plans


Slight impact.

3.3. Geology and Soils

Rannoch Moor is a flat low-level granite plateau overlain by glacial deposits and an extensive cover of blanket peat. Rannoch Moor is widely believed to be the centre of ice dispersal during the last maximum glaciation in the United Kingdom. Therefore, it exhibits important features of deglaciation and climate and landscape change. The extensive blanket peat acts as an important carbon store.

There will be no impact to the geological resource, but there will be a very slight loss of glacial deposits and peat from their original position as a result of the slight road widening and the new drainage channel. The peat will, however, be translocated to minimise its loss. There will be no change to geomorphological process rates, including those processes associated with the river.

3.4. Road Drainage and the Water Environment

Ba Bridge crosses the River Ba, which flows into Loch Ba immediately east of the bridge. This section of the river lies between Loch Ba and Lochan na Stainge and therefore has a fairly quiescent regime with little variability in flow level. The river is approximately 8 m wide and 0.75 m deep. The river is classified by the Scottish Environment Protection Agency (SEPA) as A2 or having ‘good’ water quality under their current rivers classification scheme. Under the loch classification scheme, Loch Ba has a water quality classification of ‘excellent’.

There will be no change in the hydrological regime of the river during the operational phase of the scheme and there will be some improvement to the water quality through the implementation of a catch-pit and swale which will carry the run-off from the new bridge and adjacent carriageway to enter the River Ba downstream of the bridge. Currently the road drainage runs directly off the bridge into the river.

Full consultation with SEPA indicated that there were no issues with flooding. In addition, there are no properties within the area which could be considered at risk, the road is on raised embankments and attenuation is provided by the lochs at either end of the small section of river running underneath the bridge.

3.5. Ecology and Nature Conservation

Rannoch Moor is important for nature conservation. Ba Bridge lies within Rannoch Moor SSSI and SAC and immediately adjacent to Rannoch Lochs SPA. Rannoch Moor represents the most extensive complex of blanket bog and valley mire in Britain. It is of particular importance for its range of northern mire types. Rannoch Moor is the only remaining locality for a nationally rare vascular plant species and contains several other nationally and locally rare species. There are protected species located within the area around Ba Bridge, including black-throated divers (Gavia arctica) and a protected species of freshwater invertebrate. Neither of these species will be impacted providing appropriate mitigation is in place during the construction phase of the scheme. The River Ba also contains Atlantic salmon (Salmo salar), one of the qualifying interests of the SAC. These and other aquatic fauna and flora will not be impacted from the operation of the scheme. Surveys of the area have indicated the presence of both otter (Lutra lutra) and bat species and therefore further surveys will require to be conducted prior to commencement of works to assess potential disturbance and mitigation measures which may need to be implemented.

There may be some direct habitat loss and loss of areas of vegetation and peat associated with the construction of the temporary bridge, widening of the embankments and excavation of the drainage ditch, although the majority of this impact will be minimised by adopting a programme of peatland translocation. There will be permanent loss of a number of small trees from the area immediately adjacent to the bridge.

During the operational phase, because the scheme is online, there will be no change in the impact to the ecological and nature conservation interests. However, environmental benefit will be achieved through the installation of an otter ledge which will provide a safe alternative to traversing the A82 There will be a need to monitor the peat translocation and habitat reinstatement to ensure that it is effective and that there is no long-term adverse effect to the local habitats.

3.6. Landscape Effects

Ba Bridge lies within the Ben Nevis and Glen Coe National Scenic Area and on one of Scotland’s most important tourist routes. Landscape and visual issues associated with the scheme are therefore of particular importance.

Visitors to Rannoch Moor come to experience the spectacular landscape and enjoy the views of the moor, lochs and mountains. The proposals will not alter the wider moor, but changes to the bridge will alter the immediate landscape around the bridge. The new bridge will be similar in design to the existing one but constructed with different materials. It may initially seem out of context with the landscape, but will eventually become less noticeable as the structure weathers and visitors become accustomed to it. The contractor will be required to re-establish vegetation following construction, and as this matures the residual visual impact of the scheme will lessen.

3.7. Disruption Due to Construction

During construction of the scheme there will be some disturbance to the environment. Disturbance may include an increase in noise and vibration, construction dust, impacts on views, effects on water resources and delays or obstruction to vehicular and non-vehicular traffic. Most construction impacts will be short term; however, as discussed previously, there can be long-term impacts on ecology, geology and landscape. Short-term construction impacts have the potential to cause significant disturbance to the River Ba, local fauna and the surrounding vegetation. To ensure that these receptors are protected, various mitigation measures will be put in place including fencing off sensitive areas, installation of silt traps, avoidance of working within the watercourse, and putting protective matting in place. Techniques including stitch drilling and the use of a crash deck will also help to minimise potential impacts on the watercourse by helping prevent debris entering the watercourse.

The construction compound, material storage and machinery also have the potential to cause a number of impacts, such as the visual impacts of the works, temporary reduction in local air quality from dust, construction noise and temporary reduction of access for pedestrians. To mitigate these, the contractor will keep the site tidy by storing materials appropriately, minimising vehicle movements and adhering to best practice. An Ecological Clerk of Works may be employed at the site during times of sensitive operations to ensure that best practice and the proposed mitigation measures are adhered to.

Another significant impact is the traffic management measures that will need to be implemented. One lane will be closed throughout the construction period. To reduce this impact, the scheme will be well publicised with appropriate signage to warn people of possible delays and traffic light sequences will be altered to accommodate peak times and flows.

3.8. Policies and Plans

The proposed development falls within the Highland Council area. Of relevance to the proposals is the approved Structure Plan and adopted Local Plan as well as various National Planning Policy Guidelines (NPPGs)/Scottish Planning Policies (SPPs).

The proposals are compatible with these planning guidelines and areas of minor conflict, relating mainly to temporary effects from construction are identified with relevant mitigation measures throughout the Environmental Statement.

3.9. Cumulative Impacts

With any bridge construction there may be cumulative impacts on landscape and visual receptors. The construction of Achnambeithach Bridge on the A82 further north in Glen Coe has been completed and there should be no other bridge construction projects carried out on the A82 between Bridge of Orchy and Glencoe at this time and so cumulative impacts are not expected. There are however at least a further 5 bridge replacement schemes proposed in the future for the Glencoe area.

3.10. Summary of Residual Impacts

Following the assessment of all potential impacts of the proposed development a range of mitigation measures have been identified. Implementation of these mitigation measures will reduce the majority of impacts to ‘negligible’ levels. However the following residual impacts will remain:

  • Direct loss of some trees and scrub, heathland, peat and a small amount of glacial deposits;
  • Inconvenience to travellers/tourists using the A82 during construction;
  • Physical interruption/alteration of existing views to, along and across the existing A82 road and surrounding moorland;
  • Impacts associated with the erection, operation and removal of site compound in lay-by and informal lay-by to the north of the bridge;
  • Storage of materials, waste and site compound location during construction;
  • Excavated and imported materials stockpiles causing temporary visual impact and loss of semi-natural vegetation during construction and
  • Water quality improvement downstream of existing bridge brought about by enhancement of drainage and treatment of road run-off.

4. Review and Comments

Copies of the Environmental Statement are made available for inspection during normal office hours at:

The Scottish Government

Enterprise, Transport and Lifelong Learning Department
Transport Scotland
TS Trunk Roads Network Management
TS TRNM Bridges
8th Floor
Buchanan House
58 Port Dundas Road
G4 0HF

Fort William Library

Airds Crossing
High Street
Fort William
PH33 6EU;


The National Trust for Scotland Visitor Centre

PH49 4LA.

Copies of the Environmental Statement may be purchased (at a charge of £70 for a hard copy) and are also available in CD format (at a charge of £10), or download at

All hard copy requests should be made in writing to:

Alex Gardener
The Scottish Government

Enterprise, Transport and Lifelong Learning Department
Transport Scotland
TS Trunk Roads Network Management
TS TRNM Bridges
8th Floor
Buchanan House
58 Port Dundas Road
G4 0HF

The Non-Technical Summary is available free of charge from the same address and online.

Following the publication of the Environmental Statement, there will be a period of six weeks, during which representations may be made in writing to The Chief Road Engineer at the Scottish Government Enterprise, Transport and Lifelong Learning Department at the address above. The closing date for any such representations will be as specified in the Public Notice.