Crossness Sewage Treatment Works – New Security Building

Planning Statement incorporating Design and Access

Crossness STW – New Security Building Planning Statement inc Design and Access

Contents 1. Introduction 1 2. Site Description 1 3. Background 2 4. Proposed Development 2 5. Planning Policy and Issues 2 6. Planning Appraisal 6 7. Design and Access 7 8. Conclusion 8

Thames Water Utilities Limited December 2020 1 savills.co.uk

Crossness STW – New Security Building Planning Statement inc Design and Access

1. Introduction

1.1. This Planning Statement has been prepared on behalf of Thames Water Utilities Limited (Thames Water) in support of a planning application for the erection of a new security building at Crossness Sewage Treatment Works (STW) located within the London Borough of Bexley.

2. Site Description

2.1. Crossness STW lies on the southern banks of the River Thames in the London Borough of Bexley. The operational site is bounded to the north by the River Thames, to the east by the Crossness Nature Reserve, to the south by the A2016 and to the west by the Thamesview Golf Centre.

2.2. The application site (the Site) is a small area of the overall sewage treatment works, covering around 0.2 hectares, lying at the access to the operational boundary of Crossness STW as shown on the site location plan accompanying the application. The Site is a former construction access for upgrades at the sewage treatment works which was retained under Thames Water’s permitted development rights for use as a parking area by the Crossness Engines Trust. The car park is currently utilised by Crossness Engines Trust on their Open Days and Steaming Days. When these events occur, Thames Water will provide marshalled parking on the STW site for visitors utilising the recreation ground area.

2.3. The Site is bounded to the north by offices leased by the Environment Agency, to the east by an internal access road within the sewage treatment works, to the south by an existing vegetated embankment and to the west by Bazalgette Way.

2.4. The Site lies within the Crossness Sewage Treatment Works Thames-side Special Policy Area as shown on the Bexley Unitary Development Plan Policy Map and is also designated as Metropolitan Open Land (MOL). The Site also lies close to the area of the existing sewage treatment works designated as a Special Industrial Zone. The operational boundary of the works delineated by the yellow line depicting the edge of the Thames-side Special Policy Area on the Policy Map covers an area of around 78.6ha. While the UDP Policy Map indicates that the site is within an Area Metropolitan Importance for Nature Conservation (AMINC) the Site is shown to be outside of the London Borough of Bexley Sites of Importance for Nature Conservation Report indicates that the Site is no longer within the boundary of the AMINC.

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Crossness STW – New Security Building Planning Statement inc Design and Access

3. Background

3.1. Crossness STW is Thames Water’s second largest STW covering an area of over 78 hectares. The site provides critical sewage treatment infrastructure for South London. The sewage treatment works incorporates both the treatment of sewage and sewage sludge with energy created from the biogas created during the treatment process which is used in the operation of the works. The day to day operation of the works results in a variety of movements of vehicles and personnel to and from the site associated with the management and operation of the works and the wider sewerage and water networks in the area.

3.2. The existing access arrangements for the site do not work efficiently with the internal access arrangements which have been amended as a result of upgrades to the STW. In order to provide more effective access and security arrangements on the Site it is proposed to revise the access arrangements with the existing access at the northern end of Bazalgette Way being closed and the former construction access being used for access and egress from the Site.

3.3. In order to facilitate the revised arrangements it is proposed to revise the car parking arrangements agreed with the Crossness Engines Trust with marshalled parking provided on the former sports field at Crossness STW to the north of the Environment Agency offices during events at the Crossness Engines Trust.

4. Proposed Development

4.1. The application relates to the provision of a new gatehouse building measuring 8m x 5m x 2.9m in height.

5. Planning Policy and Issues

5.1. Section 38(6) of the Planning and Compulsory Purchase Act 2004 requires that planning decisions must be made in accordance with the Development Plan unless material considerations indicate otherwise.

5.2. In this instance, the Development Plan comprises the following:

. the Mayor’s London Plan, March 2016 (the London Plan); . the Bexley Core Strategy, adopted February 2012 (the Core Strategy); and . the Saved Policies of the Bexley Unitary Development Plan 2004 (the UDP).

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Crossness STW – New Security Building Planning Statement inc Design and Access

5.3. Other material considerations in policy terms include:

. The National Planning Policy Framework (NPPF) published in February 2019 and the Planning Practice Guidance; . Bexley’s Local Plan Preparation, Regulation 18 Stage Consultation Paper, February 2019 (the emerging Local Plan); . Bexley Growth Strategy, December 2017 (the Growth Strategy); and . LB Bexley Sites of Importance for Nature Conservation Report, December 2016.

The London Plan

5.4. Policy 5.14 of the London Plan relates to water quality and wastewater infrastructure. The policy states that the Mayor will work in partnership with the boroughs and appropriate agencies within London to ensure that London has adequate and appropriate wastewater infrastructure to meet the requirements placed on it by population growth and climate change. The policy goes on to state that development proposals must ensure that adequate wastewater infrastructure capacity is available in tandem with development.

5.5. Policy 5.15 of the London Plan relates to water use and supplies and states that the Mayor will work in partnership with appropriate agencies within London to protect and conserve water supplies and resources in a sustainable manner by reaching cost effective minimum leakage levels and maintaining and upgrading water supply infrastructure.

5.6. Policy 7.17 of the London Plan relates to MOL and states that the Mayor strongly supports the protection of Metropolitan Open Land and its protection from development having an adverse impact on the openness of MOL. The policy goes on to state that inappropriate development should be refused except in very special circumstances with MOL given the same level of protection as in the Green Belt.

The Core Strategy

4.1 Policy CS09 of the Core Strategy relates to using Bexley’s resources sustainably. The policy states that development that seeks to maximize the effective and efficient use of natural and physical resources, while contributing to the health and wellbeing of the community and the environment, will be encouraged. This will be achieved through applying the requirements of national and regional planning policy and by making best use of existing physical infrastructure and working with partners to ensure infrastructure networks within the borough contribute to improving the health, safety and wellbeing of Bexley’s residents.

4.2 The subtext to Policy CS09 states that the Council will continue to work with partners to ensure the ongoing maintenance and development of physical infrastructure networks. Policy CS21 on supporting community infrastructure and services and states the Council will ensure the development of infrastructure to support housing and employment growth. They will do this by working with key delivery bodies such as utility companies to ensure the timely delivery of confirmed infrastructure and service development projects.

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Crossness STW – New Security Building Planning Statement inc Design and Access

4.3 Policy CS17 relates to green infrastructure and seeks to protect open spaces and waterways by protecting MOL from inappropriate development. Policy CS18 relates to biodiversity and states that the Council will protect and enhance its biodiversity assets including protecting Sites of Importance for Nature Conservation (SINCs). Map 4.8 of the Core Strategy shows that the Site does not lie within an AMINC and while plans in the more recent ‘Sites of Importance for Nature Conservation Report, December 2016’ show that part of the Erith Marshes AMINC lies within the STW, the Site does not lie within the AMINC but does lie adjacent to it.

The UDP

5.7. There are a number of saved policies from the UDP 2004. Of the saved policies there a some which are considered to be relevant to the development proposals which include Policy ENV15 on acceptable uses within MOL which states that there will be a presumption against permitting new buildings or the change of use of land for purposes other those set out in the policy.

5.8. Policy TS17 relates to Thames Waters operational land at Crossness STW. The policy states that the Council recognises the need to make adequate provision for future operational requirements. In considering development proposals, the Council will have regard to the following:

. the requirement for Thames Water to enhance and modernise its facilities in line with government directives; . the need to reduce significant adverse environmental impacts, such as airborne or waterborne pollution, noise, smells and unreasonable traffic generation; . the need to ensure that development in that part of the area designated as Metropolitan Open Land minimises the impact on the predominantly open character of the land; and . the need to minimise the effects of development on wildlife habitats and the need to protect rare species.

5.9. The subtext to the policy states that “Crossness Sewage Treatment Works is a major facility serving a large part of south and southeast London. As part of the Government's emphasis on achieving environmental improvements, Thames Water Utilities Limited (TWUL) is in a continual process of enhancing and modernising its activities. While the Council is not directly involved with this service, it can help to ensure that it is able to function properly. To achieve this, it is essential for the Council and Thames Water to continue to work together to identify needs and promote positive solutions. It will also be necessary for the Council to ensure that this is done in such a way as to be compatible with environmental and other policy objectives in this Plan.”

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Crossness STW – New Security Building Planning Statement inc Design and Access

National Planning Policy Framework

5.10. The National Planning Policy Framework, expresses the Government’s policies and objectives with regards to planning. The NPPF makes it clear that there is a presumption in favour of sustainable development.

5.11. Paragraph 25 of the NPPF states that strategic policy-making authorities should collaborate to identify relevant strategic matters and that they should also engage with infrastructure providers. Paragraph 26 goes on to state that joint working should help determine where additional infrastructure is necessary.

5.12. As set out within the London Plan, MOL is considered to have the same level of protection as Green Belt. Paragraph 134 of the NPPF sets out the five purposes of the Green Belt as being:

. To check the unrestricted sprawl of large built-up areas; . To prevent neighbouring towns merging into one another; . To assist in safeguarding the countryside from encroachment; . To preserve the setting and special character of historic towns; and . To assist in urban regeneration, by encouraging the recycling of derelict and other urban land.

5.13. Paragraph 143 states that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. Paragraph 145 goes on to state that construction of new buildings should be regarded as inappropriate development with some exceptions stated to this rule including the limited infilling or the partial or complete redevelopment of previously developed land which would not have a greater impact on the openness of the Green Belt that the existing development.

The Emerging Local Plan

5.14. A Regulation 18 consultation was held on preferred approaches for a new Local Plan for Bexley which ran until April 2019. There are a number of policies within the Emerging Local Plan which are of relevance to the proposed development.

5.15. Policy SP10 on Sustainable Waste Management within the Emerging Local Plan states that the Council will support sustainable waste management by: supporting regionally significant waste management infrastructure, including the Crossness Sewage Treatment Works.

5.16. Paragraph 7.39 of the Emerging Local Plan states that strategic waste management facilities will be identified within the Southeast London Joint Waste Planning Technical Paper and that these along with Crossness STW and any other identified strategic infrastructure will be set out on the policies map as appropriate.

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Crossness STW – New Security Building Planning Statement inc Design and Access

6. Planning Appraisal

Principle of Development

6.1. As set out in the London Plan, MOL is considered to carry the same level of protection as Green Belt. Paragraph 145 of the NPPF clearly indicates that the limited infilling of previously developed land is not inappropriate development provided that the development does not have a greater impact on the openness of the Green Belt or purposes of including land in it than the existing development.

6.2. While being in MOL the land the subject of the application is within the operational boundary of Crossness STW and is within the Thames-side Special Policy Area where Policy TS17 of the UDP recognizes the need to make appropriate provision for future operational requirements including the need to ensure that development in that part of the area designated as MOL minimizes the impact on the predominantly open character of the land.

6.3. The Site was previously used for access to the works in connection with major upgrade works. The access was subsequently retained to provide parking for the Crossness Engines Trust. As such there are no changes to the area other than rearranging the access arrangements for the site utilising existing areas of hardstanding. The new gatehouse security building will be provided on the existing hardstanding area.

6.4. While new buildings are considered to be inappropriate development within MOL, the NPPF sets out exceptions to this which include the limited infilling of previously developed land which would not have a greater impact on the openness of the Green Belt than the existing development. As the Site is located on previously developed land it is considered that the proposed building would constitute the limited infilling of previously developed land with the building covering just 40m2 which represents less than 0.1% of the operational boundary of the sewage treatment works.

Flood Risk

6.5. The proposed development lies within an area of Flood Zone 3 which is protected by existing defences. Appendix B provides a summary of the flood risk issues associated with the development. The scale of the building proposed and the location in an area protected by defences ensures that there would be no appreciable increase in the risk of flooding off site as a result of the development.

6.6. The proposed buildings fall within the ‘less vulnerable’ category of development set out in the Planning Practice Guidance. Such developments are considered to be appropriate within Flood Zone 3.

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Crossness STW – New Security Building Planning Statement inc Design and Access

7. Design and Access

Design

7.1. The building is a pre-fabricated office building which provides office space and welfare facilities for security guards who manage the access to the critical infrastructure site. The building has a functional appearance which is not out of keeping with existing structures and buildings within the STW or the adjacent building occupied by the Environment Agency. The flat roofed design keeps the height of the building to a minimum which reduces the visual impact.

Access

7.2. The building is proposed to ensure security at the site is maintained and to optimise the access arrangements at the Site. The Site is accessed via Bazalgette Way which provides access to the A2041 and the A2016 Eastern Way.

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Crossness STW – New Security Building Planning Statement inc Design and Access

8. Conclusion

8.1. The proposed building on the Site will help maintain the efficient and effective operation of Thames Waters assets ensuring that the access to the Site is secure.

8.2. While the Site is located in the MOL it is considered that the building would constitute appropriate development as it constitutes the limited infilling of a previously developed site in a location where it would not have any material impact on the openness of the MOL. Notwithstanding this there are also considered to be very special circumstances which would justify the building which include the ongoing requirement for enhancements and modernisation of the works acknowledged in the UDP by the Council and the need to ensure that there are suitable security arrangements in place to manage access to an essential infrastructure site.

8.3. Overall the proposed retention of the building is considered to comply with the relevant policies at a national, London wide and local level and planning permission should be granted at the earliest opportunity.

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Crossness STW – New Security Building Planning Statement inc Design and Access

Appendix 1 Flood Risk Assessment

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Crossness STW – New Security Building Planning Statement inc Design and Access

Flood Risk Appraisal

Purpose of the Building

The building is to be used to provide office and welfare facilities for security guards at Crossness STW.

Flood Risk from Rivers and the Sea

Figure 1. Flood Map for Planning – flood risk from rivers and the sea

Figure 1 shows the flood risk at Crossness STW from rivers and the sea and confirms that the site lies within flood zone 3 but that it benefits from flood defences.

Appropriateness of Development

Offices are considered to constitute ‘less vulnerable’ development under the PPG. Such development is considered to be appropriate within Flood Zone 3a. The retention of the building is therefore considered to be appropriate under the guidance set out in the PPG.

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Crossness STW – New Security Building Planning Statement inc Design and Access

Mitigation of Risks

Consideration has been given to raising the building above the predicted flood levels set out in the breach modelling for a 0.5% AEP event including allowance for climate change. However, given the nature of the building and the protection provided by existing flood defences raising the building is not considered to be appropriate.

Conclusion

The building is located within an area liable to flood but which benefits from existing flood defences as such the risk of flooding is considered to be low.

The proposals would not increase the number of people at risk of flooding as the building will be occupied by existing security guards working at the sewage treatment works.

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Crossness STW – New Security Building Planning Statement inc Design and Access

Chris Colloff BSc MSc MRTPI Associate

+44 (0) 1189520502 [email protected]

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Crossness STW – New Security Building Planning Statement inc Design and Access

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