Chapter 2.4. Description of Development

Transcription

1 Chapter 2.4. Description of Development

2 42

3 4. Description of Development 4.1. Scheme Overview The proposed South Bristol Link (SBL) comprises the construction and realignment of a section of highway 4.5 kilometres in length from the A370 Long Ashton bypass within North Somerset to the A38 and onwards to the Cater Road roundabout within the Hartcliffe area of south Bristol. This incorporates the minor realignment of sections of existing highway at Highridge Green, King Georges Road and Whitchurch Lane. The entire route is to be classed as an Urban All-Purpose Road (UAP) in accordance with TA 79/ The route includes the construction of new junctions with the A370, Brookgate, A38, Highridge Green/Highridge Road, Queens Road and Hareclive Road. New bridges will be constructed to cross Longmoor Brook, Colliter s Brook and to pass under the Bristol to Taunton Railway Line. The route corridor will incorporate a bus-only link to connect with the Ashton Vale to Temple Meads (AVTM) guided bus route, which will lead into the Long Ashton Park and Ride site. Dedicated bus lanes will be provided between the railway and the new A38 roundabout junction. New bus stops and shelters, and a continuous shared cycleway and footway will be provided along the route corridor. Associated proposals include the construction of new highway junctions, bridge structures, drainage facilities, exchange land adjacent to Highridge Common, landscaping and planting The route will form part of the West of England rapid transit network (Metro Bus), to be used by buses and other motorised vehicles. The SBL will link with the AVTM route at the Long Ashton Park and Ride site, with direct access to Bristol city centre. Within the south Bristol section, once buses have reached the Hartcliffe roundabout, services will follow existing roads via Hengrove Way to Imperial Park and onwards to Whitchurch Lane and Hengrove Park. Services will then connect with the North Fringe to Hengrove (NFH) section of the rapid transit network to route through central Bristol to the M32, Cribbs Causeway and Emerson s Green in the north For a more detailed view of the route, please refer to the scheme layout drawings in Volume 3, Appendix A370 Long Ashton Bypass to A38 Bridgwater Road The first section of the route (Zone 1) is 2 kilometres in length, which links Long Ashton to the A38 at Castle Farm via Brookgate in Ashton Vale. As part of this route, the road will pass underneath the Bristol to Exeter railway line and this will require the construction of a new underpass. Provision for General Traffic A new roundabout junction will be constructed on the A370 near Long Ashton. A dedicated left turn lane will be provided in a southbound direction on the A370, allowing traffic to access the SBL route without passing through the new roundabout junction From this roundabout, a single-carriageway, two-way, 40 mph, highway will run south-eastwards for approximately 1.5km to meet the A38 (Bridgwater Road) at a new signalised roundabout junction. This alignment will follow a route defined in the North Somerset Replacement Local Plan Between the A370 and the A38, a signal controlled junction and spur (155m in length) will be provided at Brookgate to give access to Ashton Vale, an area that includes both residential areas and industrial premises. This connection is important in improving vehicular access to this area, thereby facilitating regeneration and providing an alternative access to Winterstoke Road. 43

4 Field access points will be provided from the new carriageway along the length of the route and an access to the Viridor landfill site is also proposed to the south of the Brookgate signalised junction. These accesses will comprise at grade priority junctions. In addition an access track to Castle Farm is proposed from the SBL to the west of the A38 junction. Rapid Transit Provision A bus only link (745m in length) will be provided between the Ashton Vale to Temple Meads guided bus route to the south of Long Ashton Park and Ride site, and the new signalised junction at Brookgate The location of this connection with the AVTM route has been determined by the need to accommodate the proposed new football stadium for Bristol City Football Club. The development has planning permission but is subject to the outcome of a Town and Village Green application to be examined at an Inquiry to be held in October From the Brookgate junction to the A38, nearside bus lanes will be provided in each direction to provide dedicated provision for bus services, segregated from general traffic. Both the new A38 Bridgwater Road and Brookgate signalised junctions will include bus priority measures Rapid Transit stops will be provided at the following locations: Long Ashton Park & Ride (as part of the AVTM scheme) Brookgate (to the north of the signalised junction on the bus only link connecting to the P&R site) A38 (on the new link, immediately to the west of the Bridgwater Road junction). Provision for Pedestrians and Cyclists A new cycleway/footway will be provided on the eastern side of the carriageway between the A370 (connecting to Festival Way cycle track) and Brookgate. This links to further provision from Long Ashton Park & Ride to the A38. Controlled pedestrian / cycle crossing points are integrated into the Brookgate traffic signals to link these two sections of shared cycleway / footway. Signalised crossing points are also integrated into the proposed signalised junction formed by the A38 and SBL In places, the shared provision is set back from the carriageway, but it still provides a direct route with a similar alignment to the main highway. In addition to the shared cycleway / footway, further sections of footway are proposed to ensure access to the proposed SBL stops at: Brookgate (linking the stops to the industrial park) A38 (linking the proposed stops to signalised crossing provision at the new SBL/A38 junction) Stops will be provided at the Long Ashton Park and Ride facility as part of the Ashton Vale to Temple Meads scheme, which will be available for use by SBL rapid transit bus services. Public Rights of Way The SBL intersects some existing PROW between Long Ashton and the A38 (see Figure 5.13 of the Transport Assessment). The following mitigation measures are proposed: In proximity to the new roundabout junction, a new section of footpath will be provided to connect the two existing PROW located south of the new carriageway to reduce the need for users of these paths to cross the road. This new footway is proposed to be designated as a PROW. 44

5 To the west of Yew Tree Farm the SBL route follows the approximate alignment of a PROW running north-to-south. This existing PROW connects to two east-to-west PROW routes to the north and south of the farm building. It is proposed to amend the north-south PROW to set it back from the SBL in proximity to Colliter s Brook. It is proposed to accommodate this new route through the provision of un-signalised crossing points to the north and south where the route is intersected by the SBL carriageway. Landscape Proposals Landscape proposals for this section of the SBL route up to Brookgate include the following: Reinforcing the existing native vegetation along the north side of the A370 by filling in the gaps. A native woodland belt immediately east of the proposed A370 roundabout and on the north side of the SBL in order to provide a good belt of screening. Native hedgerow parallel to the SBL on the embankments set back sufficiently to facilitate future maintenance requirements. Scattered small groups of native trees on embankments ensuring trees are set sufficiently back from the carriageway edge. Typically feathered trees and light standards will be used. Highway grass verge immediately adjacent to carriageway. Embankments (with the exception of those in front of native tree and shrub belts) seeded with a species rich grass. A drainage basin part of which is intended to be permanently wet. Bank profiles vary to create undulating margins allowing growth of emergent vegetation. The basin structures will be seeded with a pond edge type grass mix. Seasonal variations in water levels will naturally dictate what species within the mix thrive and where With regards to the Bus Link to Railway section of the SBL route, the Environment Agency is scheduled to undertake drainage improvement works in the area. These works broadly require New Colliter s Brook to be widened and cleared out and an access strip left clear between the link road embankment and the brook The large field to the west of the brook will mostly return to agricultural use. A native hedgerow with occasional hedgerow trees just outside of the base of the embankment is proposed to recreate the field boundary Other proposals in the section will include: The integration of a drainage basin part of which is intended to be permanently wet. Bank profiles vary to create undulating margins allowing growth of emergent vegetation. The basin structures will be seeded with a pond edge type grass mix. Seasonal variations in water levels will naturally dictate what species within the mix thrive and where. Creation of a flood storage area north of the retained Community Forest Path avoiding the loss of any Category A trees. An area of native woodland to reinforce screening of the Industrial Estate. An area of native woodland west of the Brookgate junction which responds to existing hedged field boundaries and a parcel of land severed by the new road. Around the drainage basin south of the Brookgate junction it is proposed to plant small groups of native trees within species rich grass. Access for maintenance vehicles is provided alongside the existing vegetation at the southern end of the industrial estate. 45

6 For the Railway to A38 section of the SBL route, the complex topography of the location and the requirements including retaining walls, engineered slopes and cut necessitate land take and some loss of vegetation As well as protecting areas of retained trees as indicated in the Arboricultural Impact Assessment, the proposals consist of: Seeded embankments and small belts of native tree and shrub planting. The native tree and shrub planting help to tie the existing retained vegetation back into the fabric of the landscape. An area of proposed native woodland adjoining Hanging Hill Wood as a block of compensatory tree planting. Topsoil stripped through this section of woodland will be re-used locally on areas of compensatory native woodland. Embankments through the central area of this section will be covered with topsoil stripped from areas of semi-improved grassland won from other areas of the scheme. The reuse of brash and felled lumber within the landscape proposals along this section will enhance the biodiversity of the local area. Chipped brash generated from the arisings of felled vegetation will be used as hibernacula to create new habitats for amphibians, reptiles and invertebrates. North of the A38 roundabout the agricultural fields will have their boundaries re-connected through native hedgerow planting. Bridges and Structures There are a number of structures in this section as follows: Longmoor Brook Bridge: the bridge carries the SBL over Longmoor Brook watercourse and spans a 2.4m wide combined cattle, cyclist and pedestrian crossing providing a clearance of 2.4m. A mammal ledge is provided on the west abutment wall. The SBL at this location consists of a single 6.75m carriageway (two 3.375m lanes) with a 3m footpath/cycleway on the north side; with the inclusion of verges this provides an overall clear width between the bridge parapet edge beams of 11.05m. Colliter s Brook Bridge: the bridge carries the SBL over Colliter s Brook watercourse and a 1.8m wide Public Right of Way. The SBL at this location consists of a single 12.75m carriageway (two 3.375m lanes and two 3m bus lanes), with a 3m footpath/cycleway on the east side; with the inclusion of verges this provides an overall clear width between bridge parapet edge beams of 16.85m Colliter s Brook Retaining Walls North & South provided to reduce the impact of the SBL construction on the existing woodland and on the alignment of Colliter s Brook. The retaining walls are provided at two locations: North of Colliter s Brook Bridge on the east side of the South Bristol Link with a retained height of up to 3.5m South of Colliter s Brook Bridge on the west side of the South Bristol Link with a retained height of up to 5.0m Drainage and Flood Prevention During the construction phase of the SBL scheme, the following measures are proposed: New bridge crossings (Colliter s Brook and Longmoor Brook) have been designed as clear span structures with a minimum soffit level above the 1% AEP event (including an allowance for climate change) plus 0.6m freeboard; 46

7 Road levels are set to a minimum level of 1% AEP event (including an allowance for climate change) plus 0.6m freeboard; A compensatory flood storage area is proposed between the New Colliter s Brook and Longmoor Brook to mitigate for the loss of floodplain storage from the proposed raised road embankment on the left bank of the New Colliter s Brook. This will provide an additional 15,000m³ of storage capacity and result in betterment in flood risk; The proposed realignment of the Colliter s Brook adjacent the Viridor site has been designed to maintain current channel capacity to prevent any increase in flood risk; The detailed design of the proposed realignment of the Colliter s Brook and the new bridge crossings will incorporate ecological and landscape measures in order to maximise the potential for visual and nature conservation benefits in line with the WFD, whilst still allowing for appropriate maintenance. All temporary surface water detention basins will be located outside of Flood Zone 3 to ensure their continued function under flood conditions The following measures are proposed during the operational phase of the SBL: Proposed that a buried bridge consisting of a concrete slab on bank seats supported by bored piles constructed to protect existing culvert for the New Colliter s Brook A range of SUDS measures will be employed (such as detention basins, tank sewers and swales) to ensure that runoff for all new impermeable areas would be attenuated such that it would not cause or increase flooding elsewhere. Discharge from all surface water detention basins would meet Greenfield run-off rates. Mitigation for all new impermeable areas would be in the form of detention basins that would be of a size sufficient to attenuate outfall flow for a 1% AEP event (plus an allowance for climate change); Carriageways will be above known historical groundwater levels to ensure no known groundwater flood risk during operation; and Maintenance of the drainage system would be undertaken by the relevant highways authority, in accordance with their normal practices A38 to Queens Road Overview Zone 2 is a 1.5km section of the route which links the A38 at Castle Farm to Queens Road in the residential areas of Bishopsworth Provision for General Traffic From the new signalised roundabout junction formed with the A38, a new single carriageway, two-way, 40mph carriageway will extend eastwards. In proximity to Highridge Farm, the design speed will reduce to 30mph, as the carriageway enters the residential area to the east. It will cross the northern extent of Highridge Common before connecting to King Georges Road via a new four arm signalised junction formed with Highridge Road The existing alignment of Highridge Green, which currently connects to Highridge Road and King Georges Avenue at its eastern extent, will be stopped up. The road will be realigned to connect to the SBL via a new priority junction in proximity to Sandburrows Road. It will include a dedicated right turn ghost island on SBL The existing access to Highridge Cottage to the south of Highridge Green will be stopped up and a new access will be provided from the new SBL carriageway via a new three arm priority junction. 47

8 Minor widening on King Georges Road will provide for a single carriageway with an adjacent shared cycleway/footway on the north side. All existing trees are to be removed but will be replaced with native small leaved lime cullivar. The existing residential accesses over the grass verge on either side of the carriageway will be retained with verge parking formalised, however on-street parking will be removed to allow for the cycle lane provision The SBL route connects with Queen s Road / Grange Road to the east at a new signalised four arm junction. Provision for Rapid Transit Between the A38 and Queen s Road signalised junctions, the bus rapid transit will share the carriageway with general traffic. Bus priority will however be provided at the A38, Highridge Road and Queen s Road traffic signals Rapid Transit stops will be provided in either direction at Highridge Common, on approach to the Highridge Road junction from either direction. Provision for Pedestrians and Cyclists A new shared footway / cycleway will be provided on the northern edge of the new carriageway linking the A38 to King Georges Road. This will be connected to signalised pedestrian / cyclist crossing points integrated into the new traffic signals at either end of this section of the route: Signalised crossing points will be provided on the northern arm of the A38 and western arm of the SBL link at the Bridgwater Road junction. Signalised crossing points will be provided on all arms within the residential area at the junction formed between the SBL and Highridge Road Existing footways on King Georges Road, set back from the carriageway behind the grass verge will be retained. A shared cycleway/footway will be provided adjacent to the carriageway on the north side. Signalised crossing points will be provided for pedestrians and cyclists on all arms of the SBL, Queen s Road and Grange Road junction In addition, two uncontrolled crossing points are proposed on the SBL in proximity to Highridge Common comprising pedestrian refuges. Public Rights of Way The SBL intersects existing PROW in two locations between the A38 and Queen s Road (see Figure 5.13 of the Transport Assessment). Halfway between the A38 and Highridge common, an existing PROW runs east to west across the SBL route. This PROW connects to Elsbert Drive to the east and another PROW running north to south to the west of the SBL. It is proposed to provide an un-signalised crossing point to enable continued use of this PROW. A PROW runs along the western edge of Broadway and the northern edge of King Georges Road to the junction formed with Queen s Road. This PROW currently crosses the highway and therefore the proposals should not have any significant severance impact relative to the existing arrangement. Landscape Proposals The positioning of the roundabout at the A38 has enabled a group of valued remnant kilns to be retained at the centre of it. Retaining clear visibility splays on the approaches to the junction has been considered The proposals in the section include: 48

9 Reinforcing the existing screening vegetation between Castle Farm and the roundabout Native belts of tree and shrub planting which reform field boundaries as well as screening the junction and associated highway infrastructure Heading south towards Highridge Common: reinstating vegetated field boundaries with native hedgerows and occasional hedgerow trees Severed pockets of fields planted up as belts of native trees and shrubs tying into retained field hedgerows A drainage basin part of which is intended to be permanently wet. Bank profiles vary to create undulating margins allowing growth of emergent vegetation. The basin structures will be seeded with a pond edge type grass mix. Seasonal variations in water levels will naturally dictate what species within the mix thrive and where Approaching the Common from the west the design process has allowed the alignment to change enabling some category A rated trees to be retained, as well as pulling it away from Highridge Cottage. The strategy through the Common has been one of minimal land take by utilising as much of the existing road (Highridge Green) as possible. However, some of the more speciesrich areas of Highridge Common will be lost to the road construction. A turf translocation programme will be developed whereby turfs are removed in advance of road construction and translocated to suitable, stripped, ground within the compensation area/exchange land The western half of the compensation area has been identified as a suitable receptor site for turfs from Highridge Common, given proximity, similar soil conditions, and aspect. This compensation area comprises a large pastoral field. Half of this field contains poor semi-improved grassland, the other half being quite species rich unimproved and semi-improved grassland. The turfs from Highridge Common will be translocated to the species poor area of the field From the west, just before the point where the road reaches the exchange land and the common, a Gateway to the common is proposed. This is a semi formal arrangement of trees planted within the grass verge to reinforce the contrast in landscape character between agricultural land and the Common. It is proposed to use a single species of tree; the suggested species is an evergreen oak (Quercus Ilex). As part of the gateway element, appropriate signage will define the new extents of the Common. In general, the principle through the Common has been no additional planting. However, the landscape proposals must carefully respond to the landscape and visual impact. As such, some tree planting in small groups is shown on the north side of the new link to Highridge Green to buffer it in relation to nearby residential properties A group of trees will be lost at the Highridge Road junction. A replacement group is proposed adjacent to the proposed bus stop which would help absorb it into the landscape Shallow, grassed, linear depressions are proposed to aid the drainage of the common parallel with the road on the south side With regards to the section from King Georges Road to Queen s Road, positioning the footway and shared footway/cycleway to the outside, over many of the services, maximises the amount of space available for tree planting. However, there are underground services within and crossing the remaining verge which will need to be taken into account when planting trees. Planting proposals include: Semi mature tree planting within the grassed verge along King Georges Road where possible cm girth and double staked with mesh guards and root barriers. Amenity shrub planting groundcover and small to medium sized shrubs Bulb planting within grassed verges for seasonal colour Amenity grass verge Drainage and Flood Prevention During the construction phase of the SBL scheme, the following measures are proposed: 49

10 Road levels are set to a minimum level of 1% AEP event (including an allowance for climate change) plus 0.6m freeboard; A flow assessment was completed to ensure that the new culverts proposed for the Ordinary Watercourses and drainage ditches south of the A38 would be capable of providing conveyance for a 1% AEP event (including an allowance for climate change), with an additional 0.3m freeboard, in line with guidance from the DMRB. New culvert lengths have been minimised where possible; The extension of the existing A38 culvert will ensure the current culvert capacity is maintained The following measures are proposed during the operational phase of the SBL: A range of SUDS measures will be employed (such as detention basins, tank sewers and swales) to ensure that runoff for all new impermeable areas would be attenuated such that it would not cause or increase flooding elsewhere. Discharge from all surface water detention basins would meet Greenfield run-off rates. Mitigation for all new impermeable areas would be in the form of detention basins that would be of a size sufficient to attenuate outfall flow for a 1% AEP event (plus an allowance for climate change); Carriageways will be above known historical groundwater levels to ensure no known groundwater flood risk during operation; and Maintenance of the drainage system would be undertaken by the relevant highways authority, in accordance with their normal practices Queens Road to Hengrove Park Overview Zone 3 is a 3km section of the route which connects Queens Road in Bishopsworth to Hengrove Park via Imperial Park. It will use both new and existing carriageway provision. Provision for General Traffic From the new four arm signalised junction formed with Queen s Road / Grange Road, the SBL will extend eastwards on a new single carriageway, two-way road subject to a 30mph speed limit. This section of carriageway will utilise a reserved transport corridor to connect to Hareclive Road via a new four arm signalised junction. This alignment is defined in both the North Somerset Replacement Local Plan and the Bristol City Local Plan. The new signalised junction will connect: The new SBL link (western arm), Realigned Whitchurch Lane (northern and eastern arms); and, Hareclive Road (southern arm) Whitchurch Lane currently runs west-to-east linking Bishopsworth Road/Church Road to Hengrove Way. Hareclive Road connects from the south via a three arm priority junction. The proposals will involve the realignment of Whitchurch Lane so that it links to the new signalised junction, to the south of the existing priority junction formed with Hareclive Road Whitchurch Lane currently provides access to a discount foodstore and homestore in the Cater Business Park to the north-east of the existing junction formed with Hareclive Road. To maintain access to these stores, it is proposed to retain the existing section Whitchurch Lane carriageway running past these stores and converting it to an access road. This access road will form the minor arm of priority junctions formed with the realigned Whitchurch Road at either end From the new roundabout junction, the SBL route will extend eastwards on a realigned and widened section of Whitchurch Lane. This will connect the SBL route to the existing Cater Road 50

11 roundabout. Access to existing commercial properties will be provided by the use of central hatching to allow turning without causing blocking back SBL provision for general traffic will terminate at the Cater Road roundabout, with vehicles able to connect to existing highway provision. Provision for Rapid Transit From the new Queen s Road signalised junction, rapid transit buses will continue to share the single-carriageway provision with general traffic. Services will follow the new highway connection to the Cater Road roundabout junction. Rapid Transit vehicles will then route via the following existing roads: Hengrove Way to grade separated junction formed with the Imperial Retail Park, Internal access roads through the retail park connecting to Hartcliffe Way (A4174) to the east via an existing priority junction, Hartcliffe Way southbound to Hengrove Roundabout junction; and, Whitchurch Lane connecting with Hengrove Park The existing retail park access road connects Hengrove Way to Harcliffe Way (A4174) via two internal roundabout junctions. It comprises a single lane in each direction for much of its length, with a short dualled two-lane section on Wills Way connecting to the A The Rapid Transit service will utilise upgraded bus stop provision within the Imperial Retail Park. In addition, the following Rapid Transit stops will be provided on this section of the route: Queens Road (on the SBL to the east of the new signalised junction formed with Queen s Road and Grange Road), Hareclive Road (on the SBL approach to the new Hareclive Road signalised junction in either direction), Hospital (outside of the hospital in Hengrove Park) City of Bristol College (outside the college and South Bristol Skills Academy in Hengrove Park) The latter two of these stops will also be served by the North Fringe to Hengrove Rapid Transit route. Provision for Pedestrians and Cyclists There are two existing formalised paths within the reserved corridor between Queens Road and Hareclive Road linking the residential areas to the north and south. It is proposed to create a linear park on either side of the SBL route in the residential area and to provide for pedestrians and cyclists through the provision of: A shared use cycleway / footway through the park on either side of the SBL route between Goulston Road and Gatehouse Avenue; A toucan crossing connecting Goulston Road and Gatehouse Avenue via Comleaze and Gatehouse Way; Uncontrolled crossings linking Heggard Close with Innox Gardens and Selley Walk with Gatehouse Close; and A shared cycleway/footway will be provided adjacent to the SBL route between Queens Road and Cater Road roundabout on the north side. 51

12 Existing footways are present on either side of Whitchurch Lane in proximity to the Hareclive Road junction. These footways will be re-provided as part of the realignment proposals for Whitchurch Lane. These will feed into pedestrian crossing points on all arms of the new Hareclive Road traffic signals. Public Rights of Way There will not be any impact of PROW in Zone 3 between Queens Road and Hengrove Park. Landscape Proposals The proposed road alignment through the reserved corridor between Queens Road and Cater Road roundabout will require the removal of a small number of trees, scrub and bramble of low amenity value The overarching principle along this section is the creation of a strong framework of tree cover along the road corridor that links through and beyond the Hareclive Road junction. A network of small spaces will be formed along both sides of the corridor with ornamental shrub planting providing a subtle structure to define the shape A strong tree line is proposed parallel to the shared cycle/footway between Heggard Close and the Hareclive Road junction. It ties in with the existing trees that are to be retained. This spine of trees continues east of the Hareclive Road junction helping tie the proposals and pedestrian routes together. The spine is reinforced through the central section with more semi mature trees alternating between the central median and the south side of the road. East of Hareclive Road the dominance of the spine switches to the south side of the road approaching Cater Road roundabout. Other tree planting forms part of the structure that loosely defines the park spaces dotted along the corridor and around the Hareclive Road junction The planted central median will mitigate the visual impacts of the Scheme.. The median will contain park style/ornamental shrub planting and semi mature trees. It also provides a central refuge for pedestrian crossing facilities linking the residential areas on either side of the reserved corridor. Within the central median two crossings will be non-signalised and one will be signal controlled Planting proposals include: Semi mature trees, cm girth and double staked with mesh guards and root barriers; Retention of a number of existing trees that provide some screening and established structure towards the edge of the reserved corridor; Management to an existing belt of vegetation where the SBL passes through the narrow section of the reserved corridor; A 4m wide central reserve containing semi mature trees and ground cover planting; Semi formal arrangements of ornamental shrub planting; and Predominantly amenity grass with bulb planting in places for seasonal variation Where the footway is not adjacent to the westbound carriageway, kerbs shall be splayed and the grass verge will be reinforced to allow broken down vehicles to pull off the road. Drainage and Flood Prevention During the construction phase of the SBL scheme, the following measures are proposed: Road levels are set to a minimum level of 1% AEP event (including an allowance for climate change) plus 0.6m freeboard; 52

13 The extension of the existing A38 culvert will ensure the current culvert capacity is maintained. All temporary surface water detention basins will be located outside of Flood Zone 3 to ensure their continued function under flood conditions The following measures are proposed during the operational phase of the SBL: It is proposed that a buried bridge consisting of a concrete slab on bank seats supported by bored piles is constructed to protect existing culvert for the Malago A range of SUDS measures will be employed (such as detention basins, tank sewers and swales) to ensure that runoff for all new impermeable areas would be attenuated such that it would not cause or increase flooding elsewhere. Discharge from all surface water detention basins would meet Greenfield run-off rates. Mitigation for all new impermeable areas would be in the form of detention basins that would be of a size sufficient to attenuate outfall flow for a 1% AEP event (plus an allowance for climate change); Carriageways will be above known historical groundwater levels to ensure no known groundwater flood risk during operation; and Maintenance of the drainage system would be undertaken by the relevant highways authority, in accordance with their normal practices Environmental design and other measures Traffic Signs, traffic signals and street lighting would be provided in accordance with current design standards for safe operation and maintenance. The selection of luminaires that minimise glare and light spill would minimise their environmental impact wherever possible. All lighting will therefore consist of full cut off luminaries with no tilt above the horizontal plane and mounting heights reduced to a level of no more than 8m. Further information on measures taken to minimise and manage obtrusive lighting impact are set out in the Obtrusive Light Impact Assessment Report (Volume 3, Appendix 4.2) The proposed scheme has been designed to incorporate a number of features to support wildlife connectivity and biodiversity, and to assist in softening the appearance of the development in the landscape. These are briefly summarise below; further detail is provided in Table 13.9 Summary of ecological impacts and mitigation measures of Chapter 13 Ecology. Provision of bat underpasses, landscape planting designed to link habitats of value, compensatory habitat creation; provision of bat boxes Habitat translocation, protection of habitats of ecological value outside the Scheme Provision of native broadleaved woodland planting belts throughout rural section of the Scheme. Provision of approximately: 200 extra heavy standard native trees; 200 feathered trees. Programme of hedgerow translocation, and planting, gapping up remaining hedgerows, protecting hedgerows to be retained. Provision of species rich grassland on road verges, protection of habitats of ecological value outside the Scheme. Replacement of two ponds, plus provision of six additional water bodies integrated in the surface water management. Provision of mammal underpasses and mammal ledges. Provision of reptile friendly curbs, provision of landscape planting of value to reptiles Construction of the Scheme Indicative Construction programme A construction schedule is available in table 6.1 of the Transport Assessment (TA). Likely significant construction impacts are considered in the TA. This section sets out an indicative construction programme. 53

14 Hours of Working The normal working hours for the site will be to Monday to Fridays and to Saturdays with no work permitted on Sundays and Bank Holidays. Where work outside these hours is required the contractor will need to provide the following information to the local highway authorities for acceptance prior to commencing works: The proposed times of working outside the normal hours; method statements detailing how noise and vibration will be controlled and; details of consultation undertaken with effected groups; Site Compounds The main site compounds are likely to be located in the vicinity of the A370, the existing Great Western rail bridge and the A38. This would enable the substantial part of SBL to be constructed including the under bridge. Additional minor site compounds may be set up closer to the urban areas during the road refurbishment / construction works of the southern section of the route. Construction Traffic Movements and Routes The A38 and A370 are key arterial routes carrying a high volume of traffic into and out of Bristol City Centre. These two routes are likely to accommodate a large proportion of construction traffic travelling between the site and the wider network. A requirement is likely to be imposed on the contractor to maintain existing capacity on these routes during peak times and other identified traffic sensitive periods during construction, particularly construction of the proposed SBL roundabout on the A370 and the signalised roundabout on the A38. Furthermore, it is recommended where possible that access to the site compounds is provided directly from the A38 and A370 to minimise the volume of construction traffic travelling along the residential streets of south Bristol. Access to Private and Commercial Properties and to Public Access Routes The principal contractor will be required to maintain vehicular and pedestrian access to adjacent residential and business premises and to existing public access routes (footpaths, cycle routes and PROWs). The pedestrian access shall be suitable for use by wheelchairs and prams. Vehicular access will be required for emergency vehicles, deliveries, collections and public access to car parks Where access is disrupted temporary alternatives will need to be provided. Bus Stops Temporary bus stops will need to be provided where existing stops are not serviceable. Construction Environmental Management Plan Standard good construction practice would be a requirement for SBL. A preliminary Construction Environmental Management Plan (CEMP) (Volume 3, Appendix 4.3) has been produced to accompany this planning application (Reference: CTRAEB/730/DOC200). The CEMP will form the basis for more detailed construction and environmental management plans to be prepared by contractors once appointed and identifies methods of construction and parameters that form the basis of the environmental mitigation identified as being required by the ES The outline principles of construction for the scheme are as follows: Reducing the risk of any adverse impacts of the construction works on the environment and ecology. Reducing any nuisance created by construction to the nearby receptors such as neighbouring communities. 54

15 Maintaining communication between the Client, the Project Manager and relevant third parties, with assignment of any specific and/ or statutory reporting duties to third parties to the PC The following will also be produced in conjunction with the CEMP: Archaeological Management Plan An Archaeological Management Plan will be produced and appropriate measures taken before excavation works begin on site in order to safeguard and ensure the appropriate protection and investigation of archaeological remains in advance of and during construction works in the event that important archaeological remnants are discovered. Contract and Landscape and Ecology Management Plans The CEMP will also contain a maintenance schedule produced to cover the transfer of specific environmental information to the local authority and will include details about the long term maintenance of the road network and landscaping and ecology after completion of the construction works. Construction Soil Management Plan A construction soil management plan will be included within the CEMP to protecting soils, and manage and reduce the risk of soil erosion happening as a result of the construction activities A suitably qualified Environmental Clerk of Works (ECW) will be appointed to supervise implementation of all aspects of the CEMP for the Scheme, monitoring construction activities and undertaking the post-construction monitoring. The ECW will also supervise implementation of any method statements in relation to protected species, will identify the need for and liaise with specialists as required. The ECW will also be a competent ecologist capable of acting as Ecological Clerk of Works (ECoW) or will appoint and oversee such a person to implement any ecological mitigation measures. The ECW will be the main point of contact for any ecological issues, which arise as the Scheme progresses. The ECoW will ensure that a suitably licensed person is consulted/ used when required to implement mitigation for great crested newts or bats. The ECW will provide briefing to site workers in the form of toolbox talks where required A specialist archaeological advisor (AA) will also be appointed to supervise and monitor works in certain specified locations and a contaminated land specialist (CLS) will be appointed to inspect the excavations and advise on contamination issues The following are issues that will be addressed in the CEMP with particular respect to the proposed site compound(s). Traffic management, including permissible vehicle routes for construction traffic. Noise and air quality. Security. Risk of pollution and spills when refuelling in site compounds. Runoff from wheel and vehicle cleaning that may pollute water courses in the vicinity. Noise Noise levels and vibration in the residential and built up areas of the SBL will need to be monitored and controlled during the road construction works in order to meet planning requirements. The Contractor will monitor the noise and vibration levels on a regular basis particularly in the vicinity of Highridge Road, King Georges Road and Queens Road. Noise levels within the reserved corridor and Whitchurch Lane will also be monitored Not used 55

16 Water pollution and management Environmental Agency s Pollution Prevention Guidelines will be complied with in order to manage and reduce the risk of flooding. The CEMP will also set out how the water courses will be protected. Ecology and Tree Protection Measures Measures will be undertaken to avoid and reduce the negative impacts on trees within the SBL project area. These are set out in the Pre-Construction Environmental Management Plan. Air Quality The Contractor will be required to implement measures required as a condition of the planning application process to take appropriate measures such as having robust method statements for activities which generate dust particles. The following are typical measures that can be taken to reduce air pollution: Dust suppression systems to be in place at all times during works that can release dust. Earthworks and landscaping works are to be vegetated as soon as possible to prevent dust particles being generated. Topsoil stored on site for reuse should be covered to prevent it being blown away. The site is to be regularly inspected and site boundaries checked for dust and local roads are to be checked and cleaned regularly to minimise dust generation. There should be no burning on site. Archaeology and Cultural Heritage A ground investigation /archaeological study conducted in November 2011 (Ground Investigation Archaeological Watching Brief) revealed that there is potential for archaeological findings of all periods with the area of the trial pitting. Furthermore, historical records also indicate the presence of a coal mining/old quarry site near the railway bridge. There is a site of cultural heritage adjacent to the A38 Bridgwater Road which is to be retained and protected during the construction of the roundabout junction. The site consists of post medieval triple conjoined lime kilns. Contaminated Land The CEMP will describe in detail how works adjacent to or within the landfill sites are to be managed during construction works and maintained following completion of the contract. 56