Deephams Sewage Works Upgrade Environmental Statement

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1 Design Development A Landscape Strategy and Outline Landscape Management Plan is provided as Appendix The Strategy was produced in tandem with the LVIA and with input from ecologists and the design team, in order to reduce landscape and visual impacts of the proposed Upgrade works, to build in ecological mitigation and as an opportunity to provide landscape enhancements on the Site where possible. The Strategy considers the landscape character of the Site itself, as well as views towards the Site from the Lee Valley Regional Park to the east of the Site The Strategy illustrates and describes the landscape proposals to be integrated as part of the Upgrade design. This includes proposed tree/ understorey planting with native species to replace tree and vegetation losses as part of the works, enhanced landscape quality and landscape structure in the Site and at Site boundaries A number of additional measures have been built into the design of the Upgrade in order to reduce landscape and visual effects. These include: Maintaining stockpile heights to the same height as existing bunds at the northern boundary to reduce visual impacts; retaining the existing landscape buffer (strip of trees and scrub) and landscaped bund at the northern site boundary, albeit with localised vegetation losses due to the demolition and construction works; and retaining the Lea Valley Site of Metropolitan Importance for Nature Conservation (SMINC) within the Site this includes the wooded bund along the eastern boundary. The protected site is demarcated by a concrete fence and no access will be permitted to the SMINC during the enabling, demolition and construction works, other than for the purposes of agreed landscape management actions to implement the landscape strategy. Potential Sources of Effects Temporary changes arising during the construction phase of the development include: The removal of trees and vegetation within the Site and at the eastern boundary to the south and west of the SMINC; The introduction of demolition and construction activity including cranes, a construction compound and stockpiles (max 6m high and not higher than the existing bund except in the south east corner of the Site); Views of construction activity introduced to visual receptors east of the Site within the Lee Valley Regional Park as a result of removal of vegetation on the eastern boundary; and lighting during construction if work extends into hours of darkness The changes arising from the operational phase of the Upgrade would include: Replacement planting of trees and vegetation according to the Landscape Strategy; potential views of the Deephams site introduced to visual receptors east of the Site within the Lee Valley Regional Park, as a result of the loss of mature trees and vegetation on the eastern boundary; and changes to appearance and layout of structures (e.g. tanks up to approximately 22.5m high AOD) and associated infrastructure on site, as well as conversion of the existing former training building at the entrance to the site to form a new visitor centre/education facility; and new sewage works structures including settlement tanks, pumping stations and chimney stacks up to approximately 14.9m high. Chapter 13 Landscape and Visual Page of June 2014

2 13.5 Landscape Baseline Introduction Baseline Data Sources The following data sources have been used for this assessment: London Borough of Enfield, Characterisation Study (2008) and 2011 update; The Enfield Plan Core Strategy ; Extant policies from the 1994 Enfield Unitary Development Plan; Lee Valley Regional Park Authority Park Development Framework, 2011 and Regional Park Plan, 2000; Upper Lee Valley Opportunity Area Planning Framework; Ordnance Survey maps of the site, and proposal plans. Field Survey Site visits were carried out by Chartered Landscape Architects (CMLI) between 2011 and Landscape Character of the Study Area The following Landscape Character Types or Areas are found within the study area for the landscape assessment: National Landscape Character: North Thames Basin/ Hertfordshire Plateaux and River Valleys Northern Thames Basin National Character Area and the sub-character area the Hertfordshire Plateaux and River Valleys as identified by Natural England 3. This character area is a wide plateau divided by a series of broad river valleys. Large towns and outer London suburbs/urban edge uses, plus transport infrastructure/corridors such as railway lines and motorways, are prominent features. Intact areas of floodplain valley landscape survive in places, with woodland an important feature. Much of the landscape is highly modified by mineral extraction and reservoirs This landscape character area is included in the landscape baseline for context although it is not assessed because the scale of the Site and the nature of the proposals mean that there will not be any significant landscape effects at this level. Landscape character is assessed using the regional and local landscape character areas which are considered to be a more useful scale for assessing this type of proposal. Regional Landscape Character: Lea River Valley Natural Signature Lea River Valley Natural Signature ('London's Natural Signatures' report 4 ). This is a heavily modified landscape, with significant and large scale man-made interventions such as the chain of reservoirs along the channelised course of the River Lee Navigation. The report notes the presence of arterial transport corridors, large scale interwar and post war development, and industry. Other notable elements include remaining areas of open marshland several kilometres downstream of the Site (these include the Tottenham and Clapton marshes). Whilst such elements would be susceptible to change, the general character of heavily modified landscape with extensive man-made interventions, creates a landscape of low susceptibility to change. 3 Former Countryside Agency (1999) Countryside Character Volume 7: South East and London, CA13. 4 Natural England (2011) London s Natural Signatures: The London Landscape Framework. Chapter 13 Landscape and Visual Page of June 2014

3 A number of other Natural Signatures fall within the wider 5km study area, at distance from the Site. These are NS4: Finchley Ridge, NS5: Hampstead Ridge: NS7: Essex Plateau and NS9: North Thames Terraces. Due to the distance from the Site and the urban and built up nature of the surrounding area, they have not been considered further in this assessment. Landscape Character of the Site and Immediate Surroundings Local Landscape Character: Large Scale Industry The Site is identified in The 'Enfield Borough Characterisation Study', as falling within the Large scale industry urban typology. This is a belt of industrial development along the Lee Valley characterised by large buildings set within significant areas of hard standing with wide streets and entrances feeding each site. The study states that the areas have a: 'very grey character with little vegetation and only a small palette of materials and colours used for the buildings. They lack clear structure both in terms of built form and landscape and are unrefined with bleak environs. a large amount of palisade and mesh fencing with frequent bill board advertisements and signs which create a bland and poor quality environment.' The Enfield study also notes: The changing nature of industry means these areas are constantly adapting and changing format. This indicates a low susceptibility to the proposed change Due to the variability of available characterisation data for the other London boroughs within the 5km study area, and the fact that fieldwork has revealed effects on perceptual character to be confined to the Large Scale Industry Character Area in which the Site is located, other Typologies are not considered further in the assessment. Landscape Character of the Site The main landscape features in the Site are the mature broadleaf tree planted bunds and intermittent scrub to the eastern boundary (including the SMINC) and the northern boundaries. The mature vegetation to the bunds is established, as is vegetation immediately inside of the bunds, and would take considerable time to replace. Within the Site there are a limited number of small ornamental trees within the grounds of the sewage works The Site is currently a sewage works and it is therefore representative of the Large Scale Industry character type, indicating a low susceptibility to the proposed change. The vegetated bund of deciduous trees along the eastern boundary help in separating the Site from the River Lee Navigation, visually screening the existing sewage works from the wider surroundings and therefore increase the susceptibility of the Site slightly, indicating a medium susceptibility to the type of change proposed. Landscape Value of the Study Area This section sets out the relative value that is attached to different landscapes by society Valued landscapes are often recognised by designation. There are no statutory landscape designations within the study area, though there are some other designations which have implications for landscape value. These are listed below and shown on Figure Enfield Council/Urban Practitioners (2011) Enfield Characterisation Study. Chapter 13 Landscape and Visual Page of June 2014

4 The Lee Valley Regional Park Plan The Lee Valley Regional Park Authority s remit is for 'for the development, preservation and management for recreation, sport, entertainment and the enjoyment of leisure of an area adjoining the river Lee as a Regional Park.' However, it also covers protection and enhancement of the natural environment The Lee Valley Regional Park Plan, 2000 sets out a landscape strategy which identifies a number of local landscape designations and policy areas. These are: Landscape Enhancement Areas (covering the Lee Valley Golf Course adjacent to Deephams): the objectives for these are to strengthen 'areas of weak or unrecognisable character'. The intention is that this will be achieved by protecting and enhancing existing positive landscape features, resisting development which would harm the attractiveness of such features, and implementation of projects and schemes to enhance landscape character and quality. Such areas are judged to be of relatively low value in the Lee Valley Park context, albeit offering potential and landscape opportunity. Landscape Conservation Areas (covering the Navigation and associated corridor to the east of Deephams Sewage Works): the objectives for these are to protect and improve areas of high quality landscape which have strong/positive/valued landscape character. The intention is to achieve this by protection from detrimental developments, removal or improvement of features which detract from attractive landscapes, and conservation of important landscape qualities such as attractive water edges. Such areas are judged to be of moderate value in the Lee Valley Park context, in view of the sense of relative landscape intactness. In addition the Lee Valley Regional Park Development Framework (Thematic Proposals adopted in 2011) covers a number of thematic and spatial/area specific proposals for Park Development Framework Area 4, in which the Deephams site is located. Key proposals of relevance are those to enhance access to nature and physical access including cycle trails at the Camden Crushing Plant immediately east of Deephams, as part of a wider programme of post-industrial landscape restoration for this site. Also relevant are proposals to re-furbish strategic bridges over the Lee Navigation and the flood channel to facilitate lateral access in the Regional Park. Area of Special Character: The Lee Valley Rivers and Reservoirs The Lee Valley Rivers and Reservoirs Area of Special Character is located immediately adjacent to the east of the Site. The Council s policy describes limitations on development within Areas of Special Character only The Area of Special Character 'serves an important strategic body of open space for the borough providing recreation and wildlife.' Protected Characteristic traits are defined as: 'King George V and William Girling (Chingford) Reservoirs, the River Lee and Lee Navigation, marshland and grassland, Lee Valley Leisure Centre, large scale industrial buildings, mature willows and poplars lining the canal, Gunpowder Park and Enfield Island Village' This designation implies that although the landscape of the Area of Special Character has recreation and wildlife value, it does not have inherently high value in terms of landscape. This is due to the fact that such landscape features are not particularly rare in the Lee Valley context, and also reflects the Borough level nature of the designation. Chapter 13 Landscape and Visual Page of June 2014

5 Legend Landscape Designations 5km buffer Site boundary Lee Valley Regional Park Area of Special Character: the Lee Valley and Reservoirs. (Source: Area of Special Character Boundary Review, Enfield Council, 2013) Epping Forest District Landscape Strategy Areas (Source : Lee Valley Regional Park, Park Plan, Strategic Policy Framework, 1998) Landscape Enhancement Area mixture of strong and weaker landscape character requiring enhancement through design/ management Enfield London Borough Landscape Investment Area fragmented landscape character in need of major investment Lee Valley Athletics Centre Landscape Conservation Area strong landscape character to be protected Lee Valley Golf Course Waltham Forest London Borough 0 1.5km Note: All locations are approximate Ordnance Survey Crown copyright [2013] All rights reserved. Licence number Haringey London Borough Redbridge London Borough Project Title: Deephams Sewage Works Upgrade Figure Title: Landscape designations For Information Only Metres Figure 13.2 June 2014

6 Judgements on Landscape Value The Lea River Valley Natural Signature is judged to be of medium value due to the qualities associated with the Lee Valley Regional Park and to some extent, the Area of Special Character The Large scale industry character type is wholly industrialised, with eroded landscape character and therefore judged to be of low landscape value The Site is assessed as being of relatively low value as the landscape is valued at the community level Landscape Impact Assessment Likely landscape effects are assessed for significance below. Landscape Effects during Construction Effects on the character of the Site itself at construction stage would be as a result of removal of trees and vegetation within the Site and particularly at the eastern boundary to the south and west of the SMINC, demolition, breakout, excavation and construction of new structures including cranes and lighting. There will also be temporary noise barriers introduced to the northern boundary as part of the AMP5 permitted development works which will reduce the vegetated character of the boundary over a small section. However, the assessment assumes these to be already in place as part of the baseline. The removal of trees is discussed in more detail below in relation to operational effects on the Site and in the Arboricultural Impact Assessment (Appendix 5.2). During the construction phase the removal of trees on the eastern boundary, will affect the character of the eastern part of the site by breaking up the continuous belt of relatively mature trees in this location. At the eastern boundary there will be a loss of 36 trees classed as Category C and U and predominantly hybrid black poplar and cherry, mostly between 15-20m tall. It should also be noted that many of the trees show signs of storm damage, thus slightly reducing their landscape value The effect of removal of trees on the eastern boundary will alter the perception of the Site to no more than a medium degree, as construction works and the operational Deephams Site itself will become more noticeable. Elsewhere within the Site the level of construction effects are likely to be small. Effects will occur in a very localised area and will be temporary during the construction phase (operational effects are discussed below and in relation to proposed planting as part of the Landscape Strategy). Effects will be on a landscape receptor of low susceptibility and low value, and therefore in the context of the temporary nature of the effects and localised extent, and in view of the fact that they occur in a landscape already characterised by much on-going construction activity, the level of effect is likely to be minor adverse. Local and Regional Landscape Character Areas Very localised effects will be experienced on the perceptual character of the Lee Valley Natural Signature, in the context of other similar activity. Effects will be felt at the local level, over a very small geographic extent, they will be temporary during construction (over 39 months) and therefore of short duration and partially reversible (as structures are rebuilt) on a receptor of low susceptibility and medium value, therefore a negligible effect Localised effects on the perceptual character of the Large Scale Industry Character Area as a result of construction activity on the Site would be felt at the local level and would be of small scale and extent in the context of the wider landscape, and Chapter 13 Landscape and Visual Page of June 2014

7 short term in duration, and reversible in nature on a receptor of low susceptibility and low value. They are therefore judged to be minor adverse. Landscape Effects during Operation Built-in Mitigation The proposed Landscape Strategy and Outline Management Plan describes and illustrates proposals for planting of trees and vegetation, and habitat enhancements across the Site. This Strategy has been built in as part of the design. Proposed landscape enhancements within the Site include planting of tree, scrub and thicket on the eastern boundary with appropriate native species, native woodland, copse and thicket planting to the north eastern boundary and mixed native planting to the north western boundary The line of coniferous trees in the north west corner of the Site between the construction compound and Picketts Lock Lane are diseased and will require removal in the future. The Landscape Strategy proposes to replace these trees over time, before they are removed, with appropriate replacement species (e.g. pine and silver birch which exist on the Site and provide screening to adjacent properties) in order to maintain landscape structure in this area With regard to site lighting, it has been assumed for the purposes of assessment that this will be designed to be equivalent to the Institute of Lighting Engineers category E3 (Medium district brightness areas/urban locations) with all luminaires to be of modern, full cut off design to minimise glare and sky glow. Character of the Site and Immediate Surroundings Operational effects will arise primarily as a result of the loss of trees and vegetation on the eastern boundary, to the south and west of the SMINC (albeit realised from construction stage a permanent impact). There will be a loss of 36 trees classed as Category C and U in the Tree Schedule 6 and predominantly hybrid black poplar and cherry, most of which are between 15-20m tall and relatively mature. Some of the trees are therefore dominant and together form an important landscape boundary feature (though it should be noted that many show signs of storm damage). The trees are of relatively high landscape value due to the rarity of landscape features across the Site Across the Site as a whole, the Arboricultural Impact Assessment identifies that there will be a loss of 76 individual trees and 11 groups of trees (of which a number will only be partial loss). These are primarily Category C and U trees, with six Category B trees and one group, and one Category A tree within the centre of the Site. These are illustrated in plan DWG 012 Rev A of the Arboricultural Impact Assessment. The Arboricultural Impact Assessment concludes that the tree loss across the Site will justified as it will be balanced against the natural degeneration and loss through structural decline of the trees, as well as the implementation of the Landscape Strategy and Outline Landscape Management Plan The loss of the trees and vegetation at the eastern boundary would result in a change to the vegetated character and landscape structure of the eastern boundary and locally to the Site, in that more of the on site infrastructure and lighting would potentially be visible. The loss of the eastern boundary trees will however, be compensated by the proposed planting as set out in the Landscape Strategy over time as it matures The scale of effect on the character of the Site and immediate surroundings at year 6 See Arboricultural Impact Assessment Appendix 5.2) Wharton Arboriculture, June Chapter 13 Landscape and Visual Page of June 2014

8 0 of operation is considered to be no more than medium in a localised area on the eastern boundary, but in the context of the Site overall is considered to be small. The scale of effect will reduce over time, as the proposed planting implemented as part of the landscape strategy, matures. The scale of effect after 5 years is considered to be no more than small for the Site overall, and after 10 years is considered to be minor beneficial. The effects will occur on a low susceptibility receptor of low value which will be permanent/long term and part reversible (due to replacement planting). The level of effect is therefore judged to be Moderate Adverse at year 0 of operation, in a localised area and Minor Adverse for the Site as a whole. After 5 years the level of effect is judged to be no more than Minor Adverse, and after 10 years in summer is judged to be minor beneficial. Landscape Character Areas Perceptual effects on the Lee Valley Natural Signature, will be felt at the local level and be of localised geographic extent. They are considered to be of very small scale in relation to the size of the area affected, on a receptor of low susceptibility and medium value. The effects would relate mainly to localised loss of boundary vegetation and replacement planting (which would not perceptibly affect wider landscape character), and would therefore be long term and part reversible, albeit negligible due to the small scale of the area affected The Large Scale Industry Landscape Character Type in which the Site is located would experience minor adverse effects on perceptual character at Year 0 of operation of the Site, due to the part of loss of boundary vegetation and bund (albeit compensated with new native planting) and recognising the industrial character this area already has. Effects would be felt at the local level and would be of long term duration, and part reversible (offset of vegetation loss with new planting as it matures) on a receptor of low susceptibility and low value. Effects will reduce to minor beneficial in 10 years (summer 10 years after completion) particularly after replacement planting implemented at the site boundary matures. Residual Effects As all mitigation measures have been designed into the scheme, the residual effects will remain as set out above and in Table Summary of Residual Landscape Effects It is anticipated that there will be very few significant effects on landscape components or landscape character as a result of the operation of the Upgrade. This is largely due to the current use of the Site as a sewage works and that the Upgrade use therefore fits well with surrounding landscape character, largely reflecting the existing site as well as landscape proposals as part of the landscape Strategy. Table 13.7: Summary of Residual Landscape Effects Phase Receptor Residual significance Construction The Site Minor Adverse Construction Lee Valley Natural Signature Negligible Construction Large scale industry Landscape Character Typology Minor Adverse Operation The Site Year 0 of operation: Locally Moderate Chapter 13 Landscape and Visual Page of June 2014

9 Phase Receptor Residual significance Operation Lee Valley Natural Signature Negligible Adverse and Minor Adverse for the Site as a whole; Year 5 as planting matures: no more than Minor Adverse; Year 10 in summer: Minor Beneficial as new planting reaches maturity. Operation Large scale industry Landscape Character Typology Year 0 of operation: Minor Adverse; Year 10 in summer: Minor Beneficial as new planting reaches maturity Visual Baseline This section identifies the extent of possible visibility of the Upgrade, and identifies the visual receptors that have been assessed. This section also introduces the viewpoints that have been used to assess effects on receptors, including reasons for their selection. Analysis of Visibility of the Development The Site lies in a built up area of the Lee Valley. Its visual context comprises industrial estates to the south, road and rail corridors and Edmonton town centre to the west, housing and the Lee Valley Leisure Complex to the north, and the Lee Navigation and the William Girling Reservoir to the east The density and height of built development around the Site and the steep banks of the William Girling Reservoir currently contain views of the Deephams Sewage Works to within relatively close proximity Much of the footprint of the Site is currently occupied by the sewage works and attendant mid to late 20th century buildings and infrastructure. The Site is essentially flat, except for a small raised area in the north west corner and a vegetated earth bund which forms part of the northern and much of the eastern site boundary. The northern, eastern and western boundaries of the Site are defined by tree lines. The grassed banks of William Girling Reservoir limit views from the east of the Site Site visits to the study area indicated that views of the existing sewage works are confined to approximately 1.5km of the Site (it is noted that the proposed development within the Site will be generally of a similar scale and massing to the existing works, albeit on a smaller footprint 7 ). There is very limited visibility to the north and west of the Site. Valued Views There are no protected views (as designated in London s View Management Framework) in the vicinity of the Site. LBE has identified a number of locally important views 8 in relation to tall buildings (it should be noted that the Upgrade is not considered to constitute tall buildings although the views are considered as part of the baseline). Locally important views in proximity to the Site are illustrated on Figure 13.3 and listed below: 7 It is however noted that new above ground tanks on site are generally higher than existing as they are built on existing base slabs and the front end of the work has been raised in relation to existing, in order to improve hydraulic profile and gravitational flow through the works. 8 Report on location of tall buildings and important local views in Enfield, March 2013, Enfield Council Chapter 13 Landscape and Visual Page of June 2014

10 Mansfield Park - 'Fine panoramic views of the southern part of the borough from inside the park entrance at the top of Mansfield Hill at the junction with the Ridgeway looking west across the reservoirs.' Ponders End - from the bridges over the railway line: 'The bridges over the railway line and over Meridian Way provide corridor views looking south towards the City of London and Docklands with the tall buildings clearly visible and silhouetted on the horizon.' Potential Visual Receptors Potential visual receptors include: residents of Picketts Lock Lane immediately to the north of the Site (approximately 40 houses 9 ) and Lock Keepers Cottage to the north east of the Site; recreational users of the Lee Valley Golf Course and Lee Valley Athletics Centre, part of the Lee Valley Leisure Complex approximately 200m to the north of the Site; walkers on Pymmes Brook Trail (the section on Picketts Lock Lane) immediately to the north of the Site; workers in the Ardra Industrial Estate immediately to the south of the Site; cyclists on National Cycle Route 1, walkers and motorists on Lee Park Way immediately to the east of the Site; recreational users of the Lee Navigation (canal boats and moorings) and walkers on the towpath (public right of way) to the east of the river, to the east of the Site - recreational users of the Lee Valley Regional Park; residents of Chingford (within approximately 2km to the east of the Site); and recreational users of Mansfield Park. 9 The group of properties along Picketts Lock Lane are considered as one receptor /group of receptors for the purposes of this assessment. Chapter 13 Landscape and Visual Page of June 2014