Sdr Appendix u Dcs

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Appendix U Deptford Church Street (formerly Borthwick Wharf Foreshore)

Appendix U Deptford Church Street (formerly Borthwick Wharf

Foreshore)

U.1 Introduction

U.1.1 This appendix sets out the site selection process that we used and ourrationale for identifying our preferred phase one and phase twoconsultation sites to intercept the Deptford Storm Relief CSO.

Type of siteU.1.2 We need a worksite to connect the local combined sewer overflow (CSO),

known as the Deptford Storm Relief CSO, to the Greenwich connectiontunnel which will transfer flows to the main tunnel. To enable theconnection to be made the site needs to be as close as possible to the lineof the existing sewers.

Site selection process

U.1.3 All potential worksites have been identified in accordance with ourSiteselection methodology paper(SSM), which involved a sieving approach,commencing with identification of all potentially suitable areas of land(excluding concentrated residential sites and World Heritage Sites) andpassing these sites through increasingly detailed levels of assessment tomove from a long list to a draft short list, a final short list and finally a list ofpreferred sites for phase one consultation.


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U.2 Site selection up to phase one consultation

Assessment of the long list sitesU.2.1 The long list of potential sites to intercept the Deptford Storm Relief CSO

was created by conducting a desktop survey of the land in the vicinity ofthe existing sewer.

U.2.2 After an initial group of sites were identified in the vicinity of the CSO,further investigations found that the CSO could also be intercepted furtherinland near the Deptford Creek. This resulted in an additional group ofsites being considered to intercept the Deptford Storm Relief CSO.

U.2.3 In total, 23 sites were included on the long list. These sites wereassessed having regard to the high-level considerations set out in Table2.2 of the SSM (hereafter referred to as Table 2.2) including engineering(site size, site features, access and availability of jetty/wharf facilities),planning and environment (heritage, landscape/townscape, open spaceand ecological) and community and property (neighbouring land uses, site

use, Special Land/Crown Land and acquisition costs) considerations.

U.2.4 The table below provides a summary of the outcome of the Table 2.2assessment in respect of the long list of sites considered for theinterception of this CSO. Sites which were assessed as being the leastconstrained when considered against Table 2.2 considerations passed tothe draft short list. This did not necessarily mean that a site wouldultimately be judged as suitable, but that no significant constraints were

identified in relation to the high level considerations addressed at Table


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Site IDSite name/description

Recommendation and rationale

C32XEParking area to flatsfronting DeptfordGreen*

Recommendation: Not to draft shortlist

Rationale: The site is small and veryrestrictive making it impractical forconstruction works.

C32XFParking area fordevelopment offStowage*


Rationale: The engineering connection tothe sewer is long and difficult.

C32XGParking area fordevelopment offBasevi Way*


Rationale: The engineering connection tothe sewer is technically impractical due tolength of connection.

C32XHOpen area frontingMcMillan Street

Recommendation: To draft shortlist

C32XJ

Grounds in front ofSt Paul's Church,Deptford ChurchStreet**


Rationale: There are a number ofheritage constraints which would restrictproposed development.

C32XK

Parking area rear offlat off Deptford

Church Recommendation: To draft shortlist


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C32XRPlayground and carpark off FrankhamStreet**


Rationale: The site comprises aplayground and parking for a school. Theland comprises special land for thepurposes of the ALA 1981 or Crown land.Furthermore, the acquisition costs likely tobe relatively high.

C32XS

Grass verge andadventure area offDeptford ChurchStreet**


C32XTEntrance area to

Lewisham College**


Rationale: There will be operationalimpact on Lewisham College. The land

comprises special land for the purposes ofthe ALA 1981 or Crown land.Furthermore, the acquisition costs likely tobe relatively high.

C32XUIndustrial area offCreekside**


Rationale: The site is too narrow andrestrictive.

Hardstanding Recommendation: Not to draft shortlist


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Assessment of draft short list sites

U.2.6 The nine draft short list sites identified for further assessment at the nextstage were:

C32XA: Borthwick Wharf Foreshore

C32XB: The AHOY Centre

C32XC: Gardens of block of flats fronting Deptford Green

C32XH: Open area fronting McMillan Street

C32XK: Parking area rear of flat off Deptford Church Street/DeptfordChurch Street

C32XL: Land adjacent Bronze Street

C32XM: Grounds of Charlotte Turner Primary School off BorthwickStreet

C32XN: Gardens fronting flats off Mary Ann Buildings

C32XS: Grass verge and adventure area off Deptford Church Street.

U.2.7 These sites were further assessed by the engineering, planning,environment, community and property disciplines, having regard to theconsiderations set out in Table 2.3 of the SSM (hereafter referred to asTable 2.3). This stage of the process built on the information gatheredand assessment undertaken at long list stage but focussed on more

detailed local considerations


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Table U.2 Draft short list to final short list for the interception of theDeptford Storm Relief CSO (Table 2.3 assessment)



C32XABorthwick WharfForeshore*

Recommendation: Retain on short list

C32XB The AHOY Centre* Recommendation: Retain on short list

C32XCGardens of block offlats frontingDeptford Green*


C32XH Open area fronting

Recommendation: Not to shortlist

Rationale: Engineering Very difficult location for

interception with major electricalservices running through the site.

Planning/Environment While severalplanning applications for residentialunits have been refused, the site isallocated for housing, so there is a risk

the site may not be available if


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C32XLLand adjacentBronze Street**


Rationale:

Engineering The engineeringconnection is likely to be difficult as thelarge interception chamber would needto be in busy Deptford Church Streetand likely to cause major disruption

across the whole road. Planning/Environment There will be a

cumulative impact on a number ofdesignations including open space aswell as an effect on residential amenity.

Community There will be impacts onresidential areas and communityfacilities in the area.

C32XM

Grounds of CharlotteTurner PrimarySchool off BorthwickStreet*


Rationale:

Engineering The connectionarrangements are very constrained bylack of space very close to flats.

Community The site is located withinthe grounds of a school, so it is likely to

ha e impact on comm nit cohesion


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C32XS

Grass verge andadventure area offDeptford ChurchStreet**


Rationale:

Planning/Environment The LondonBorough of Lewisham has identifiedthis site within the Deptford TownCentre Regeneration Plan, and its usefor the Thames Tunnel project may

interfere with the regenerationobjectives for the area.

NB. The Site ID and Site name/description were used as an internal mechanismto record and describe the site but may be updated if necessary. Sites marked *are located in the London Borough of Greenwich while sites marked ** arelocated in the London Borough of Lewisham.

U.2.10 Of the nine sites on the draft short list, three were assessed as potentiallysuitable and passed to the final short list whilst six sites did not proceed tothe final short list.

Assessment of the final short list sites

U.2.11 The three sites identified for inclusion on the final short list andassessment at the next stage were:

C32XA: Borthwick Wharf Foreshore

C32XB Th AHOY C t


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would need to investigate potential use of the existing jetty and bargingmovements.

U.2.17 Planning: On balance, the site was considered less suitable for a CSOinterception site because the site is within close proximity of residentialproperties and there will also be potential conflict with the existing yachtclub use.

U.2.18 Environment: Overall, the site was assessed as less suitable for use asa CSO site. The site was considered likely to besuitable from theperspectives of archaeology, built heritage and groundwater. However,

the site was consideredless suitable from the perspective of transport,townscape, surface water, ecology, flood risk, noise, air quality and landquality, and these impacts would require mitigation.

U.2.19 Socio-economic and community: The site was considered lesssuitable for a CSO interception site due to its potential impacts on theAHOY Centre yacht club and the equalities groups that use this. Thiscentre requires access to the river for its activities which would be severely

disrupted by the proposed works.

U.2.20 Property: The site was considered suitable for use as a CSO site as theacquisition cost should be low and the site is undeveloped. However, theland is likely to be Crown land and an additional compensation may beneeded with the AHOY Centre.

C32XB: The AHOY Centre

U 2 21 Sit C32XB i tl i d b th AHOY C t ht l b th


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U.2.27 Property: The site was considered less suitable for use as a CSO siteon the grounds of unacceptable acquisition costs, unless the design can

be revised to reduce the impact on the AHOY Centre.

C32XC: Gardens of block of flats fronting Deptford Green

U.2.28 Site C32XC is currently occupied by the communal gardens of an adjacentblock of flats which front onto Deptford Green, within the London Boroughof Greenwich. The site also takes up a small area of a primary school

U.2.29 The site is adjacent to a park to the west, an electricity substation to the

north and Benbow Street to the south. The residential flats are situated tothe east of the site. A public footpath also crosses the site.

U.2.30 Engineering: The site was assessed as suitablefor use as a CSO site.However, road access is restricted and there are engineering complexitiesas a result of the adjacent electricity substation and associated buriedcables.

U.2.31 Planning: On balance, the site was considered not suitable as a CSO

site because there are a number of planning and environmentaldesignations relating to the site. Furthermore, the proximity of the site toresidential properties and a primary school is likely to be unacceptable.

U.2.32 Environment: Overall, the site was assessed asless suitable for use asa CSO site. The site was considered likely to besuitable from theperspectives of archaeology, built heritage, hydrogeology, surface water,ecology and flood risk. However, the site was consideredless suitable

f th ti f t t t i i lit d l d


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C32XA would have the best potential to provide the required workingarea. C32XB and C32XC would both be too small to provide an

efficient and safe working area for the type of shaft constructionenvisaged.

Use of site C32XB would mean an extended period that the AHOYCentre would be affected and there would be difficulty in providingalternative sailing facilities. The site is also in close proximity to amajor high voltage (HV) substation, which would have a number ofsevere construction implications.

C32XC is in close proximity to residential properties, a school and playarea, meaning significant conflict with Greenwich Unitary DevelopmentPlan policies. The interception works would be outside of the site andwould impact on the local road network and major HV substation. Inaddition, the site may require the use of a special parliamentaryprocedure for its acquisition as it is owned by the local authority.

While there are likely to be impacts resulting from the use of C32XA,including impacts on the AHOY Centre, it is considered thatconstraints at this site are better able to be addressed and mitigationprovided than for the alternative sites.

U.3 Review of site selection following phase one consultation

Phase one consultation responses

U 3 1 A t f th it l ti th d l ll f db k i d d i th


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Back-check process

U.3.5 Since phase one consultation began, we have carried out more technicalstudies, which have suggested that the use of our preferred site atBorthwick Wharf Foreshore may not be the best solution. We consideredfactors such as difficult site access and, in this particular location, theconstruction constraints caused by the position of the existing wharf andsewer outfall.

U.3.6 As a result of these factors, and having regard to the feedback receivedduring phase one consultation including that received from theEnvironment Agency, we began a back-check (as outlined in the Siteselection methodology paper) to review our selection of Borthwick WharfForeshore. This included an investigation to see if there were any feasibleland-based sites to intercept the existing local CSO. We are alsoreconsidering the alignment of the connection tunnel that will link theGreenwich Pumping Station and Deptford Storm Relief CSOs to the maintunnel.

U.3.7 The back-check involved a targeted repeat of each relevant stage of oursite selection process to reconsider which site would be most suitable forthe interception of the Deptford Storm Relief CSO. The following outlinesthe results from each stage of the back-check process.

Assessment of the back-check long list

U.3.8 The original long list sites for Deptford Storm Relief CSO contained 23

it ( T bl U 1) Th it i d l ith it


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C32XLLand adjacentBronze Street**


C32XM

Grounds of CharlotteTurner PrimarySchool off Borthwick

Street*


Rationale: Building the interceptionchamber may not be feasible due to thelarge number of major electrical cablesthat are on top of the existing sewer.

C32XNGardens frontingflats off Mary AnnBuildings**


C32XPCar park to sportscomplex offResolution Way**


Rationale: There is a long and difficult

connection between drop shaft andinterception chamber.

C32XQGardens frontingFrankham Street**


Rationale: The site is located withinresidential curtilage.

C32XRPlayground and carpark off Frankham

St t**


Rationale: The site is a playground and

ki f h l


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C32XXGarden area toflats**


Rationale: There is a long and difficultconnection between drop shaft andinterception chamber. Furthermore, thesite is very restrictive and the access ispoor.

C32XYGarden area andparking to flats**


Rationale: There is a long and difficultconnection between drop shaft andinterception chamber. Furthermore, thesite is very restrictive and the access ispoor.

C32XZDeptford ChurchStreet**


C32YAPaynes andBorthwick Wharves*




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Table U.4 Draft short list to final short list for the interception of theDeptford Storm Relief CSO (Table 2.3 assessment)



C32XABorthwick WharfForeshore*


C32XB The AHOY Centre*


Rationale: Engineering There are constraints on

general access, site features and size.There are also considerable constraintson connection feasibility.

Community Concerned about overallcommunity impact. The AHOY Centreaims to help disabled anddisadvantaged youths, so there wouldbe a disproportionate impact on themand other users of the centre. There isalso dense residential use adjacent tothe site and a nearby park.


Rationale:

E i i Diffi lt ti


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C32XN

Gardens fronting

flats off Mary AnnBuildings**


Rationale:

Engineering Difficult interception andsome constraint due to site beingnarrow.

Planning/Environment Cumulativeimpact on a number of designations

including open space as well as theaffect on residential amenity. Maycause some disruption to DeptfordChurch Street, but less than sites onthe other side of the road.

Community Main concern is impacton a number of sensitive receptorsadjacent to the site including a church

and affect on residential amenity.


Rationale:

Engineering Difficult connection asthe large interception chamber wouldneed to be in busy Deptford ChurchStreet close to the roundabout, which

k i l l i h di ti


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C32YAPaynes andBorthwick Wharves*


Rationale:

Engineering - constraints working in theriver, site features (including listedstructures on the site), shaft level,connection to interception chamber andon general site access

Planning/Environment - extant planningpermission for mixed use residentialredevelopment

Property - if development commences,site may no longer be available.Acquisition cost likely to be significant.

Community - park and primary school arelocated to the south of the site could affect

community cohesion, the health and well-being of the local community and maydisproportionately impact on young peoplein the area



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these potential effects, lorries would still need to be used to transportsome materials to and from the site. Furthermore, the use of barges at

this site would be complicated by the existing jetty and may conflict withother river users in this area. Therefore after engineering reviewed thisSSR in light of this new information, they have changed theirrecommendation to less suitable.

U.3.24 Property also noted some road access would be needed, so there wouldbe a need to acquire vehicular access rights over private estate roads.This may be difficult and potentially raise the issue of compensation.

While property did not change theirsuitable recommendation, thiselement creates more risks.

C32XL: Land adjacent Bronze Street

U.3.25 Site C32XL is public open space located within the London Borough ofLewisham. The site is adjacent to the St Pauls Conservation Area andthere are a number of listed buildings and structures in the vicinity.

U.3.26 The site is bounded by three roads with residential properties to the south,and a church and primary school to the west. A railway line also runs tothe south of the site.

U.3.27 The original assessment was based on the premise the sewer to beintercepted was located in the central reservation of Deptford ChurchStreet, which would be likely to require the complete closure of DeptfordChurch Street to undertake the interception works. Further detailed

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U.3.31 Socio-economic and community: The site was considered lesssuitable as a CSO site. Use of the site may result in temporary loss of

open space which could have a value to the local community.Construction works are also likely to cause noise and visual disruption tosurrounding residents and a childrens play area. The need to work in thecarriageway of Deptford Church Street also appears likely to impact ontraffic flow in the area, which could also impact on local residents.

U.3.32 Property: The site was considered suitable for use as a CSO site as thesite acquisition costs are likely to be acceptable if assessed on a

diminution in value basis, or on the basis of providing temporaryreplacement land. However, if acquisition cannot be agreed andreplacement land cannot be provided, the order may need to pass througha special parliamentary procedure.

C32XZ: Deptford Church Street

U.3.33 Site C32XZ is public open space located within the London Borough ofLewisham. The site is within the St Pauls Conservation Area andadjacent to listed buildings and structures in the vicinity.

U.3.34 The site is bounded by Deptford Church Street (A2209) to the east, CoffeyStreet to the north and Crossfield Street to the south. There areresidential properties located to the east on the opposite side of DeptfordChurch Street, and a school is located to the southwest.

U.3.35 Engineering: The site was assessed as suitable for use as a CSO site

th it i l t th i ti t li f d h t


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U.3.39 Property: The site was considered suitable for use as a CSO site as thesite acquisition costs are likely to be acceptable if assessed on a

diminution in value basis, or on the basis of providing temporaryreplacement land. However, if acquisition cannot be agreed andreplacement land cannot be provided, the order may need to pass througha special parliamentary procedure.

U.4 Preferred site recommendation

U.4.1 Following the completion of the back-check process, a multidisciplinary

workshop was held to compare the originally preferred site (BorthwickWharf Foreshore) with the new sites identified via the back-check.

U.4.2 This workshop took into account the findings of all the SSRs and thefeedback received during the phase one consultation. On the basis of theassessments described above and professional judgement, it was agreedby all disciplines that Deptford Church Street (C32XZ) should becomethe preferred site for the interception of the Deptford Storm Relief

CSO at phase two consultation. This meant that we believe this to bethe most appropriate site, subject to further engagement with stakeholdersand further design development to verify this conclusion prior to phase twoconsultation.

U.4.3 In summary, Deptford Church Street (C32XZ) was identified as the mostsuitable site because:

it has much better access than Borthwick Wharf foreshore


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by the Design Council CABE (formerly the Commission for Architectureand the Built Environment). The reviews for Deptford Church Street were

attended by the London Borough of Lewisham and our pan-Londonstakeholders.

U.5.4 We have undertaken a series of drop-in sessions to present and discussthe potential suitability of Deptford Church Street as an alternativepreferred site. These comments have been considered and details areprovided in the Interim engagement report.

Construction layoutU.5.5 In response to stakeholder engagement, phase one consultation

responses and scheme development, the construction layout of the sitehas been altered to minimise impact on the local community andenvironment, and is guided by operational and functional requirements.Particular factors at this site that have influenced the layout are as follows:

The drop shaft has been located as centrally as possible within the

site to maximise distance from sensitive receptors such as the Grade Ilisted St Pauls Church, St Josephs Roman Catholic Primary School,and the Grade II listed viaduct.

We have designed a construction access to this site that includes aone-way system. This would be safe for pedestrians and vehicles onsurrounding roads and footpaths and provide a controlled access forvehicles entering and leaving site. It would also help ensure safety on

i b d i h d f hi l i hi h i


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engagement and scheme development. The conclusion reached was thatDeptford Church Street should become the preferred site for the

interception of the Deptford Storm Relief CSO at phase twoconsultation.

U.6.2 Phase two consultation will provide an opportunity for the public tocomment on our revised preferred site and scheme for the Thames Tunnelproject, before we publicise our proposed application.


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Annex U.1


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!(

C32XD

C32XL

C32YAC32XA

C32XP

C32XJ

C32XZ

C32XY

C32XS

C32XR

C32XM

C32XQ

C32XK

C32XC

C32XT

C32XW

C32XN

C32XB

C32XH

C32XU

C32XF

C32XG

C32XX

C32XE

C32XV

CS32X

Preferred List: CSO SitesCS32X

Deptford Storm Relief

The Point,7thFloor,

37NorthWharf Road,Paddington, London W2 1AF

Thames Water Utilities

Le g e n d

!(

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