6. Flood Risk to Planned Development

6.1 Introduction In line with development targets set by the regional plans and in line with the Council’s Local Development Scheme (LDS), Pendle Borough Council is currently considering allocations of land for future development. As outlined in Section 2, there are plans for regeneration and redevelopment of brownfield sites in urban areas throughout the Borough, and there may be a need for future growth in adjacent greenfield areas. The key areas of development are planned in Nelson, Brierfield and Colne based on areas of housing market decline identified for strengthening by the HMR Pathfinder programme (see Box 2.1). Most future development will be focused on the urban areas. Flood risk is an important consideration in guiding the location of new development in the Borough, highlighted by previous flood incidents that have caused the inundation of properties, some of which have been repeatedly affected. The key objective of this SFRA is to assess flood risk throughout the Borough, focussing in particular on areas at risk and where development is planned, to ensure informed planning decisions that reduce flood risk. In terms of assessing these areas, the emerging PPS 25 is the key policy driver. The PPS 25 Sequential Test provides a rigorous process for assessing and prioritising the location of planned development with respect to flood risk. It is primarily based on the Environment Agency’s flood zones defined by the probability of flooding from rivers and the sea, but also requires other sources of flooding to be considered, together with potential future flood risks (such as changes in land use or climate) and residual flood risks. The overriding aim of the Sequential Test is to steer all new development to the lowest flood risk zone (i.e. zone 1). Where this is not possible, depending on its vulnerability, development may be permitted in the higher risk flood zones if the criteria of the Exception Test are met (see Section 4.2.2). This section provides an assessment of the potential areas in the Borough in which development may occur in line with the objectives of the PPS 25 Sequential Test, with a view to informing planning decisions on the location of future development. The local flood risks identified in each area can then guide more detailed FRAs of sites selected for development.

6.2 Potential Development Areas Currently the areas which are likely to be the subject of future or redevelopment in Pendle Borough are based on the HMR Pathfinder programme (see Box 2.1) and are shown in Figure 2.1. Figures 6.1 to 6.3 show the areas in more detail for Nelson, Brierfield and Colne respectively. The following sections comprise an assessment of the local flood risks affecting each site.

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6.2.1 South Valley AAP South Valley AAP is a 154 hectare area situated approximately 4 kilometres northeast of Nelson Town Centre (see Figure 6.3 and Plate 6.1). The existing urban area of Colne forms the northern boundary, with Carry Bridge and Primet Bridge to the east and west respectively. To the south, land slopes up towards Deerstone Moor. The areas covers existing residential development, industry in the lower area of the site adjacent to Colne Water (Lenches), and a large area of predominantly open fields used for pasture, hedgerows and some wooded areas along the watercourses. Detailed proposals for the regeneration of the area are not yet available, though may involve some new development in the valley bottom along with environmental improvements to the existing landscape and townscape across the remainder of the area. Colne Water flows in a westerly direction through the site. Church Clough Brook and a number of other minor tributaries of Colne Water also flow through the southern part of the site in a northerly direction to Colne Water. Potential flood risks to consider with respect to the redevelopment of the South Valley site include: • Fluvial flooding from Colne Water. Figure 6.3 shows that parts of the site lie in the medium and high risk flood zones 2 and 3; • Fluvial flooding from Church Clough Brook and other minor tributaries of Colne Water. The Environment Agency has not derived flood zones for these small watercourses. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of any existing bridges/ culverts and/ or any new crossings proposed in association with new development; • Sewer flooding due to capacity exceedance, backing up or blockages of existing and/ or new surface water networks proposed in association with new development;

• Overland flow from upslope fields to the south and urban areas to the north;

• Possible groundwater flooding associated with springs near the heads of the minor tributaries.

6.2.2 Bradley AAP The Bradley AAP site is a 32 hectare area situated just to the north of Nelson Town Centre (see Figure 6.1). Currently the area mostly comprises terraced housing together with two large mill complexes; Throstle Nest Mill and the now derelict site of the former Riverside Mill. Currently the proposals to regenerate the area includes the clearing of some areas for new build housing and open space, while other areas have been identified for possible environmental improvements or facelift. Walverden Water passes through the site including through the grounds of Riverside Mill (see Plate 6.2). It is culverted under part of the mill site, and from the mill to the Bradley AAP boundary. The NFCDD indicates capacities of 1 in 25 to 50 years for the Walverden Water culverts. Hendon Brook is also culverted under the site and joins the culverted Walverden Water on site.

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Plate 6.1 View of South Valley from Kiln Hill, looking north down towards Colne

Plate 6.2 Riverside Mill, looking southeast from Charles Street

Walverden Water flows in from the right behind the remains of the steel framed building, and then flows from the chimney stack towards the brick wall where it enters the culvert under Charles Street.

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Potential flood risks to consider with respect to the redevelopment of the Bradley site include:

• Fluvial flooding from Walverden Water. Figure 6.1 shows that parts of the site lie in the medium and high risk flood zones 2 and 3;

• Fluvial flooding from Hendon Brook. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted sections of Walverden Water and Hendon Brook; • Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

6.2.3 Brierfield Railway Street AAP The Brierfield Railway Street AAP is a 10 hectare area situated approximately 2.5 kilometres south of Nelson Town Centre (see Plate 6.3 and Figure 6.2). The Colne-Burnley Railway forms the western boundary, and the A682 the eastern boundary. Currently the area mostly comprises terraced housing, several shops and places of worship. Detailed proposals for the regeneration of these areas are not yet available, though they may include a mixture of clearance for new build housing and open space, facelifting, group repair and associated environmental improvements. The Sefton Street COW and Hollin Mill COW (both now enmained) are culverted through the south and north of the site respectively. Potential flood risks to consider with respect to the redevelopment of the Brierfield Railway Street site include: • Fluvial flooding from the Sefton Street and Hollin Mill COWs. The Environment Agency has not derived flood zones for these small watercourses. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Sefton Street and Hollin Mill COWs; • Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

6.2.4 Churchfields, Colne PAA Churchfields PAA is a 1.4 hectare area situated just west of Colne Town Centre (see Figure 6.3). Currently the area is predominantly terraced houses. Redevelopment proposals include group repair and garden extensions with some demolition to allow for a small housing development and a community garden. The North Valley Stream is culverted just to the north of the Churchfields area.

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Plate 6.3 View of the Railway Street Corridor

Looking south down Cross Street, across Railway Street and up Sackville Street. The Sefton Street COW follows Montague Street, passes underneath Sackville Street, before passing down under Holden Street Mill (and the Brierfield Canal Corridor) and under the canal towards Pendle Water.

Potential flood risks to consider with respect to the redevelopment of the Churchfields site include: • Fluvial flooding in the northern edge of the site from the North Valley Stream. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required;

• Blockages and/ or insufficient capacity of the culverted North Valley Stream;

• Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area;

• Overland flow from surrounding urban areas.

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6.2.5 Southfield PAA Southfield PAA is a 6.8 hectare area situated adjacent to the south eastern edge of Nelson Town Centre. It is bounded in the south by Barkerhouse Road, in the north by Hallam Road and in the west by the Burnley-Colne railway (see Figure 6.1). Currently the area comprises terraced houses, commercial premises and a mill. Detailed proposals for the regeneration of the area are not yet available. Hendon Brook is culverted just to the north. Potential flood risks to consider with respect to the redevelopment of the Southfield site include: • Fluvial flooding from Hendon Brook. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Hendon Brook;

• Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

6.2.6 Whitefield PAA Whitefield PAA is a 32 hectare area situated adjacent to the south western edge of Nelson Town Centre. Manchester Road forms the southern boundary and the Leeds and Liverpool Canal most of the northern boundary (see Figure 6.1). Currently the area comprises large numbers of terraced houses, commercial premises and several mills. The redevelopment proposals include the internal re-design of many of the existing buildings, some new development, facelifting and group repair, as well as associated environmental improvements. Edge End Brook is culverted just to the southwest of the Whitefield area. Potential flood risks to consider with respect to the redevelopment of the Whitefield site include: • Fluvial flooding in the south western corner of the site from Edge End Brook. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Edge End Brook;

• Flood risks associated with the Leeds and Liverpool Canal;

• Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

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6.2.7 Stanley Street Neighbourhood PAA The exact extent of the Stanley Street Corridor PAA was not available for the purposes of this SFRA although the approximate area is shown in Figure 6.2. Detailed proposals for the regeneration of this area are not yet available. The Sefton Street COW and Hollin Mill COW (both now enmained) are culverted along the southern boundary and through the site respectively. Potential flood risks to consider with respect to the redevelopment of the Stanley Street Neighbourhood site include: • Fluvial flooding from the Sefton Street and Hollin Mill COWs. The Environment Agency has not derived flood zones for these small watercourses. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Sefton Street and Hollin Mill COWs; • Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

6.2.8 Brierfield Canal Corridor PAA The Brierfield Canal Corridor PAA consists of three areas comprising 8.4 hectares in total situated approximately 2.5 kilometres southwest of Nelson Town Centre (see Figure 6.2 and Plate 6.4). The sites are located on the northwest, northeast and southeast corners of the B6428 road crossing of the Leeds and Liverpool Canal. Currently the northwest area comprises 101 properties in Berkeley Street, Claremont Street, Belgrave Street and Veevers Street as well as land adjacent to the canal. The southeast area comprises 37 terraced properties along King Street and lower Holden Road, as well as the adjacent mill. The Council intends to redevelop the sites for new housing, retaining part of the Lob Lane Mill complex for residential conversion. The Sefton Street COW (now enmained) is culverted underneath the southeast area. The northeast area, the Brierfield Mill Complex, is an area identified by the Brierfield ADF as an area with potential to offer more employment and innovative business opportunities. Currently the area includes the BSN factory in a grade 2 listed mill and is used for light industrial purposes but offers opportunities for re-using vacant floorspace and refurbishment. Detailed proposals are not yet available, though it is likely to include the construction of new office and light-industrial units to increase employment opportunities. The Hollin Mill COW (now enmained) is culverted underneath the northeast corner.

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Plate 6.4 View of the Brierfield Canal Corridor looking southwest from King Street

The Sefton Street COW flows from left to right under the terraced houses at the topographic low point indicated by the gold-coloured car.

Potential flood risks to consider with respect to the redevelopment of the Brierfield Canal Corridor site include:

• Fluvial flooding from the Hollin Mill and Sefton Street COWs. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required;

• Blockages and/ or insufficient capacity of the culverted Hollin Mill and Sefton Street COWs;

• Flood risks associated with the Leeds and Liverpool Canal; • Sewer flooding due to capacity exceedance, backing up or blockages of the surface water network serving the area; • Overland flow from surrounding urban areas.

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6.2.9 Knotts Lane HMR Reserved Housing Site The Knotts Lane reserved area in the Local Plan comprises 7.9 hectares situated on the western edge of the South Valley site (see Figure 6.3 and Plate 6.5). The site is bounded by the Colne urban area to the north, and on the other sides by the Turn Hill recreation ground and open fields. Currently the area is open fields and hedgerows. Detailed future proposals are not yet available, though any development will be new build on greenfield land. The Primet Bridge COW (now enmained) and several of its minor tributaries flow through the site. Potential flood risks to consider with respect to the redevelopment of the Knotts Lane site includes: • Fluvial flooding from the Primet Bridge COW and minor tributaries. The Environment Agency has not derived flood zones for these small watercourses. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of any existing bridges/ culverts and/ or any new crossings proposed in association with new development; • Sewer flooding due to capacity exceedance, backing up or blockages of any new surface water network proposed in association with new development; • Overland flow from upslope fields;

• Possible groundwater flooding associated with springs near the heads of the minor tributaries.

Plate 6.5 View of the Knotts Lane site from Knotts Drive, looking south

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6.2.10 Gib Hill HMR Reserved Housing Site The Gib Hill reserved area in the Local Plan is 12 hectares situated approximately 2.5 kilometres northeast of Nelson Town Centre (see Figure 6.1 and Plate 6.6). The existing urban area of Nelson-Colne forms the northern and western boundaries, and a golf course lies to the east. Currently the area comprises open fields, hedgerows and wooded areas. Detailed proposals for future use are not yet available, though any development will be new build on greenfield land. Several minor tributaries of Swindon Clough flow through the site in a north westerly direction. Potential flood risks to consider with respect to the redevelopment of the Gib Hill site include: • Fluvial flooding from the minor tributaries of Swindon Clough. The Environment Agency has not derived flood zones for these small watercourses. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of any existing bridges/ culverts and/ or any new crossings proposed in association with new development; • Sewer flooding due to capacity exceedance, backing up or blockages of any new surface water network proposed in association with new development; • Overland flow from upslope fields;

• Possible groundwater flooding associated with springs near the heads of the minor tributaries.

Plate 6.6 View of the Gib Hill site from Liddesdale, looking north

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6.2.11 Further Clough Head HMR Reserved Housing Site The Further Clough Head reserved area in the Local Plan is 3.7 hectares situated approximately 1 kilometre southeast of Nelson Town Centre (see Figure 6.1 and Plate 6.7). It is located adjacent to the existing urban area of Nelson with open fields to the south and east. Currently the area is open fields and hedgerows. Detailed proposals for future use are not yet available, though the development will be new build on greenfield land. Clough Head Beck flows in a south westerly direction through the site towards Walverden Water. It is open channel up- and down-stream of the site, but culverted underneath an embankment on site. Potential flood risks to consider with respect to the redevelopment of the Further Clough Head site include: • Fluvial flooding from Clough Head Beck. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Clough Head Beck;

• Sewer flooding due to capacity exceedance, backing up or blockages of any new surface water network proposed in association with new development; • Overland flow from upslope fields and urban areas;

• Possible groundwater flooding associated with springs near the heads of any minor tributaries.

Plate 6.7 Views of Further Clough Head site

The left image is looking south from Pinewood Drive, whilst the image on the right is the view east, up Clough Head – note the new development sited well above Clough Head and reinforcement of the upper slope.

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6.2.12 Clitheroe Road HMR Reserved Housing Site The Clitheroe Road reserved area in the Local Plan is 2.1 hectares situated approximately 2 kilometres southwest of Nelson Town Centre (see Figure 6.2). Currently the area is an open grassed field bounded by the Leeds and Liverpool Canal in the east, residential areas in the north and woodland in the south. Detailed future proposals are not yet available, though any development will be new build on greenfield land. The Sefton Street COW (now enmained) is culverted just to the north of the site. Potential flood risks to consider with respect to the redevelopment of the Clitheroe Road site include: • Fluvial flooding from the Sefton Street COW. The Environment Agency has not derived flood zones for this small watercourse. Further investigations to assess the extent of the associated flood risks will be required; • Blockages and/ or insufficient capacity of the culverted Sefton Street COW;

• Flood risks associated with the Leeds and Liverpool Canal;

• Sewer flooding due to capacity exceedance, backing up or blockages of new surface water networks proposed in association with new development; • Overland flow from upslope areas.

6.2.13 Former Lucas Playing Fields HMR Reserved Housing Site The Former Lucas Playing Field reserved area in the Local Plan is 2.6 hectares situated approximately 2 kilometres southwest of Nelson Town Centre (see Figure 6.2). Currently the area is a sports/ playing fields complex including some buildings surrounded by the existing urban area of Reedley/ Brierfield. Detailed future proposals are not yet available for this site. Potential flood risks to consider with respect to the redevelopment of the Lucas Playing Field site include: • Sewer flooding due to capacity exceedance, backing up or blockages of existing and/ or new surface water networks proposed in association with new development; • Overland flow from surrounding urban areas. Figure 6.2 does not indicate any watercourses flowing through the site though there are some minor watercourses, including sources and sinks, nearby. The presence of any springs or open channel and/ or culverted watercourses that could pose a potential flood risk to the site may need to be confirmed.

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6.2.14 Former James Nelson Sports Ground HMR Reserved Housing Site The Former James Nelson Sports Ground reserved area in the Local Plan is 1.8 hectares situated approximately 1 kilometre southeast of Nelson Town Centre (see Figure 6.1). It is located adjacent to the existing urban area of Nelson with allotment gardens to the east and west. Currently the area is a redundant sports field adjacent to an unused pavilion. Detailed proposals for future use are not yet available, though the development will be new build on greenfield land. Springs issue to the north and west of the site and flow in a south westerly direction towards Walverden Water. Potential flood risks to consider with respect to the redevelopment of the Former James Nelson Sports Ground site include: • Sewer flooding due to capacity exceedance, backing up or blockages of any new surface water network proposed in association with new development; • Overland flow from upslope fields and urban areas. Figure 6.1 does not indicate any watercourses flowing through the site though there are some minor watercourses, including sources and sinks, nearby. The presence of any springs or open channel and/ or culverted watercourses that could pose a potential flood risk to the site may need to be confirmed.

6.3 Urban Areas In addition to the specific development areas considered in detail above, a broad assessment of the flood risk to the main urban areas has been undertaken. The following sections summarise these by main catchment area (see Figure 5.4): • The Colne-Nelson-Brierfield corridor, Carr Hall, Barrowford and Higherford, Trawden, and Foulridge in the Calder catchment in the south; • Barnoldswick and Salterforth in the Ribble catchment in the northwest; and

• Earby and Kelbrook in the Aire catchment in the northeast.

6.3.1 Calder Catchment

Colne-Nelson-Brierfield Corridor The key sources of flood risk identified in the Colne-Nelson-Brierfield corridor (see Figure 6.4) are: • Pendle, Colne and Walverden Waters and Trawden Beck (main rivers);

• The North Valley, Primet Bridge, Swindon Clough, Hendon Brook, Edge Hill, Hollin Mill and Sefton Street COWs (now enmained); • Ordinary watercourses which drain into the above main rivers and COWs;

• The Leeds and Liverpool Canal; and

• Overland flow.

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Detailed modelling of the flood risk due to the main rivers of Pendle and Colne Waters and Trawden Beck has been undertaken by the Environment Agency under the Section 105 modelling framework (see Table 5.5 and Figure 5.6). Design flood levels and floodplain extents are therefore available along these watercourses, which take into account structures and defences. Flood risk due to Walverden Water has only been modelled in lesser detail as part of the national Flood Map using JFLOW (see Section 5.3.2). Development should be steered away from the higher risk flood zones (i.e. zones 2 and 3) associated with these watercourses, particularly on greenfield land. The Ribble CFMP indicates that some areas of Nelson have a Standard of Protection (SoP) as low as 10% (i.e. 1 in 10 year) and that culverts on Walverden Water have capacities between 2 and 4% (i.e. 1 in 25 to 50 year). The historic flood extents in Lomeshaye and Walverden are shown in Figures 5.1 and 5.3 respectively. For redevelopment of brownfield sites in the higher risk flood zones, a detailed FRA would be required to demonstrate the proposals meet the Exception Test (see Section 4.2.2) and adequately mitigate the risks. Seven COWs flow through the urban corridor, of which significant lengths are culverted. None of these watercourses have been modelled to determine the extent of flood risk. For developments over and adjacent to these COWs, further investigations will be required to ensure development is not placed at unacceptable risk of flooding either due to flood events in the catchments and/ or culvert blockages. There are also numerous ordinary watercourses feeding into the main rivers through the corridor. Again, none of these have been modelled to determine the extent of the flood risk. Developments near to these watercourses may also require further investigations, commensurate with the potential risks posed to any planned development. The Leeds and Liverpool Canal passes through the Colne-Nelson-Brierfield urban corridor which can pose a number of different flood risks (see Section 5.4.4). Most of the corridor is at a higher level than the canal however, which will minimise some of the potential risks. However, the potential for localised flood problems should be considered where other watercourses cross the canal (either through culverting or sluice). Section 5.4 summarises the general risks associated with drainage systems, overland flow, sewer and groundwater flooding and outlines the relevant guidance to consider.

Carr Hall, Barrowford and Higherford The generic risks outlined above should also be considered for Carr Hall, Barrowford and Higherford. Although there are no former COWs in these settlements, the Clough Springs tributary of Pendle Water at Newbridge has been associated with past flooding events due to exceedence of culvert capacity under the mill. Significant areas of Barrowford are within the high risk flood zones of Pendle Water, and any development planned here should carefully consider the flood risk and present SoP. The historic flood extent in Barrowford is shown in Figure 5.4.

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Trawden The generic risks outlined above should also be considered for Trawden. Although there are no former COWs in Trawden, Trawden Beck becomes main river at Trawden and presents a potential flood risk to the settlement. The steep slope of this watercourse minimises the extent of flood risk and so problems are likely to be predominantly related to constrictive structures in the floodplain and associated upstream afflux effects. The Ribble CFMP indicates that bridges in Trawden have capacities of around 2% (i.e. 1 in 50 year).

Foulridge No particular local flood risks have been identified in Foulridge. Overland flow and surface water management are therefore the main issues to consider with Pendle Borough Council recording several gullies on their problem ‘hotspots’ list (see Appendix D).

6.3.2 Ribble Catchment (Barnoldswick and Salterforth) There have been a number of historical flood incidents in the Ribble catchment in the northwest of the Borough, primarily associated with Stock Beck and its tributaries in Barnoldswick. None of these watercourses have been modelled in detail to determine design flood levels and extent of flood risk. Flood risk has only been modelled in lesser detail as part of the national Flood Map using JFLOW where the catchment exceeds 3 km2 (see Figure 6.5 and Section 5.3.2). Past flooding issues can be summarised as follows:

• Land to the east of the Leeds and Liverpool Canal. The embanked canal and hills rising up behind eastern Barnoldswick mean this area is situated in a topographic bowl; drainage of this area is through artificial channels (culverts) under the canal to the receiving watercourse (Stock Beck) northwest of the canal. Blockage or inadequate capacity of these systems results in water collecting and ponding extensively in this area (see Figure 6.5);

• Flood risk associated with watercourses draining from Weets Hill (see Plate 6.8) west of Barnoldswick, particularly associated with culverts under mills and roads and the encroached floodplains of the upper Stock Beck and its tributaries in the Wapping/ Town Head and Gisburn Road/ Westfield Mill areas of Barnoldswick; • Flooding in Salterforth due to malfunctioning of a sluice on the Leeds and Liverpool Canal causing some localised flooding, including of several properties. To the east of Barnoldswick, Pendle Borough Council has instigated the reopening of a third disused culvert and has repaired damage to one culvert. Whilst flooding has not reoccurred at Ghyll Meadows (see Plate 6.8) from subsequent storms, the SoP of the culvert capacities have not been confirmed. The Council are also investigating flooding associated with Crowsnest Syke with current indications suggesting problems with the trash screen. Any planned development will need to investigate these issues further to assess current and future risks. SuDS are particularly emphasised in this area to limit development runoff to greenfield levels.

Plate 6.8 Views of Weets Hill and Ghyll Meadow

Top: View of Weets Hill looking southwest from the B6252 Leeds and Liverpool Canal bridge. Note steep slopes and incised watercourses visible on hill side. Bottom: View of Ghyll Meadow looking southeast from Coates Lane. The Rolls-Royce sports ground which has been inundated on a number of occasions is located behind Ghyll Meadows. The low hills rising up behind can just be seen above the bungalows.

The Leeds and Liverpool Canal passes through the Barnoldswick area which can pose a number of different flood risks (see Section 5.4.4). It has been known to hinder drainage of areas behind the embankment (as outlined above) and presents risks of local flooding where watercourses cross the canal (either through culverting or sluice). Areas of Barnoldswick are also downslope of the canal which also puts them at a remote risk due to infrastructure failure. Limited information is available on flood issues to the west of Barnoldswick. It appears that small groups of properties are liable to frequent flooding from surcharged culverts and small watercourses. No further investigations or mitigation measures are currently proposed. Detailed modelling of flood risk along a short reach of the Salterforth Beck has been undertaken by the Environment Agency under the Section 105 modelling framework (see Table 5.5). The modelling indicated that the Beck does not pose a flood risk to Salterforth for all events up to the 1% (1 in 100 year) event.

6.3.3 Aire Catchment (Earby and Kelbrook) Earby and Kelbrook have a history of flooding problems associated with Earby Beck and its tributaries (see Plate 6.9). Detailed modelling of the flood risk has been undertaken by the Environment Agency under the Section 105 modelling framework (see Table 5.5 and Figure 5.7). Design flood levels and floodplain extents are therefore available along these watercourses, which take into account structures and defences. Development should be steered away from the higher risk flood zones (i.e. zones 2 and 3) associated with these watercourses, particularly on greenfield land. For redevelopment of brownfield sites in the higher risk flood zones, a detailed FRA would be required to demonstrate the proposals meet the Exception Test (see Section 4.2.2) and adequately mitigate the risks. Flooding issues based on past problems and the detailed modelling can be summarised as follows:

• Flooding of the Water Street area by Earby Beck (see Plates 6.10 and 6.11), caused by limited channel capacity, encroachment and in-channel obstructions (low drive and bridge accesses). Flows escape from the Beck at various driveway accesses along Water Street downstream of Selbourne Terrace, and in particular at the junction of Water Street and Stony Bank Road. Flows rejoin New Cut in the Victoria Road and Albert Street area of Earby however this is restricted by discharge flaps when levels in the New Cut are high; • Flooding associated with New Cut upstream of Earby village centre, Cricket Ground and Brookfield Way/ Dale Way areas, primarily due to encroachment of the floodplain (see Plate 6.12); • Flooding in Kelbrook from Kelbrook Beck along Harden Road, caused by limited channel capacity, encroachment and in-channel obstructions. The Council have since constructed gullies from the road into the beck and no subsequent problems have yet occurred. The Section 105 modelling study identified some potential alleviation options for Earby including flood walls along Water Street, temporary flood barriers for houses (although limited warning time would be available in the steep catchment), and maintenance and enhancements to pumping systems for the drainage network around Victoria and Albert Roads. However no further investigations are currently proposed. Any planned development will need to consider the risks assessed by the Section 105 study, as well as the potential for any other secondary sources of flood risk. SuDS are particularly emphasised in this area to limit development runoff to greenfield levels.

Plate 6.9 Views of Earby Beck

Top left: View of Earby Beck looking north from School Lane. Note new development alongside watercourse and new flood walls.

Top right: View of ad-hoc defences (planks bolted onto railings) along Earby Beck on School Lane.

Bottom left: View of New Cut looking south from Victoria Road. Note open banktop on right.

Bottom Right: View of Earby Beck looking up Water Street with Selbourne Terrace in the centre of the picture. Note constrictive bridges over watercourse.

Plate 6.10 View of Earby Beck looking up Water Street, Earby during 2004 flood event

(Source: Environment Agency)

Plate 6.11 View of Earby Beck looking up Water Street, Earby during 2004 flood event

Note: surcharging from channel at full capacity above drive access in foreground. (Source: Environment Agency)

Plate 6.12 View of Brookfield Way across New Cut during the 2004 Flood

(Source: Environment Agency)

6.4 Conclusions Current proposals for development in Pendle centre around the redevelopment of key brownfield sites and housing market renewal, with new development on greenfield areas planned only if required to meet additional future growth. Only the forthcoming Core Strategy and Allocations Development Plan Documents (DPDs) can identify if such land will be needed. The flood risks of potential development areas and the main settlements in Pendle have been assessed to inform future planning decisions of the flood risks.

6.4.1 Potential Development Areas Most of the potential development areas lie in zone 1, with only the Bradley and South Valley AAPs including land in higher flood risk zones. In both these areas however, only a limited portion of the sites lie in zones 2 and 3. However, the Environment Agency flood zones only indicate fluvial flood risk due to the major watercourses (i.e. with a catchment larger than 3 km2), and many of the potential development areas lie alongside, or near, other smaller watercourses which may pose flood risks that are just as significant, particularly risks posed by COWs. In fact, all of the AAP and PAA sites (South Valley, Bradley, Brierfield Railway Street, Churchfields, Southfield, Whitefield, Stanley Street Neighbourhood and Brierfield Canal Corridor) have COWs flowing through or near to the site. Of the six HMR reserved housing sites in the Local Plan, two (Knotts Lane and Clitheroe Road) are alongside or near COWs, and two (Further Clough Head and Gib Hill) are alongside or near other ordinary watercourses. The remaining two sites, Former Lucas Playing Fields and Former James Nelson Sports Ground, lie in the vicinity of ordinary watercourses and/ or springs.

Potential secondary sources of flood risk were also considered for each of the potential development areas using a variety of information sources including historical records, Ordnance Survey maps and site visits. One of the key issues identified was the flood risk associated with the potential blockage and/ or insufficient capacity of watercourses, particularly the culverted COWs. This is known to have exacerbated a number of flood incidents in the Borough in the past.

6.4.2 Urban Areas The most significant flood risk issue with respect to existing and future development in urban areas within Pendle Borough are areas that lie adjacent to COWs, and along Colne and Pendle Waters. Although in some areas, current and planned flood alleviation schemes help mitigate fluvial flood risk, there remains a residual risk for development in these areas. For all development in the vicinity of watercourses, consideration must be given to flood risk both in terms of high flows overtopping banks, as well as flooding associated with blockages of culverts and/ or other structures along the watercourses.

6.5 Recommendations In line with the PPS 25 Sequential Test, any potential development should be steered to the lowest risk Environment Agency flood zones (which take account of the primary source of flooding, i.e. from major rivers), however other sources of flood risk including minor watercourses, overland flow, sewer and groundwater flooding should also be considered, and a sequential approach applied to these risks too. Based on the strategic assessment of flood risks facing potential development areas in Pendle Borough, the following recommendations have been made to guide the development planning process: • Flood Zones 2 and 3: South Valley and Bradley AAPs, together with urban areas along Colne and Pendle Waters and Earby Beck, include land within zones 2 and 3. In line with the Sequential Test, development should ideally be steered away from these zones to areas of lowest risk, i.e. zone 1. Should development in zones 2 and 3 be required, a preference should be given to low vulnerability land uses (for example, recreational and amenity). Other types of land use must be considered in terms of their vulnerability to flood risk. In zone 2, highly vulnerable land use (see Table 4.1 and Appendix B) must pass the PPS 25 Exception Test. In zone 3, highly vulnerable land use is not permitted, and more vulnerable land use and essential infrastructure must pass the PPS 25 Exception Test. Flood resistance and resilience mitigation measures (see Section 7.5) should be employed in these zones to adequately reduce the risk. These measures typically include finished floor levels a minimum freeboard above a design flood level;

• COWs: All of the AAPs (except South Valley) and PAAs, together with the Knotts Lane and Clitheroe Road HMR reserved areas include, or are near to, COWs. These watercourses will require further investigation to delineate the areas of land that lie within zones 2 and 3. Development in these areas should then be treated as above (see previous bullet point), with development steered to lower risk areas, or directing low vulnerability land uses to these zones. Again, if other types of land use are required in these zones, and pass the PPS 25 Exception Test, mitigation measures should be employed to address the risks; • Other watercourses: The remaining 4 HMR reserved areas away from the main rivers and COWs (Gib Hill, Further Clough Head, Former Lucas Playing Fields, and Former James Nelson Sports Ground) are still within the vicinity of other minor watercourses. These may also require further investigation to assess whether development may be in zones 2 or 3. Development in these zones should also be treated as above (see first bullet point); • Culvert blockage: All of the AAPs (except South Valley) and PAAs, together with the Further Clough Head and Clitheroe Road HMR reserved areas include, or are near to, culverted sections of watercourse. This presents a risk of flooding due to blockage which has been known to exacerbate flooding in the past, and should be investigated at the detailed FRA stage to assess the risk and mitigate as necessary; • Secondary risks: All potential development areas must assess and mitigate other secondary sources of flood risk at the detailed FRA stage, including (but not necessarily limited to) the local risks identified in each of the potential development areas (e.g. overland flow, sewer and groundwater flooding); • SuDS: The incorporation of SuDS should be encouraged in all development, both existing and future, to control runoff and reduce downstream flood risk. PPS 25 requires that SuDS are implemented in new development wherever practical to prevent the generation of additional runoff. In particular problem areas, SuDS can also be retrofitted to existing development to alleviate downstream flooding; • Flood Risk Assessments: A detailed FRA will be required for all sites selected for development (and any other proposed major developments12 in the Borough) due to the potential for generation of additional surface water runoff. In addition, the FRA will need to address the local flood risks relevant to the site, and where applicable meet other PPS 25 requirements including (but not necessarily limited to) the Sequential Test, Exception Test, flooding over the lifetime of the development (e.g. taking into account climate and land use change) and residual risks. Where all of these various flood risk issues are appropriately considered, the Borough of Pendle should be able to contribute to the vitality of the urban areas, whilst controlling flood risk to people and property.

12 According to PPS 25,“a major development is one in which the number of dwellings to be constructed is 10 or more, or the site area is equal to or greater than 0.5 ha. Non-residential developments are defined as major if they involve a floor space equal to or greater than 1 000 m2, or a site area greater than 1 ha.”