Spelthorne Borough Council

The General Location of Development

STRATEGY

Summary

5.1

The strategy, which is illustrated in the Key Diagram, is to locate new development within existing urban areas, focussing development that may generate large amounts of traffic to town and local centres and major Employment Areas that are accessible by a choice of travel modes. The strategy seeks to make effective use of existing urban land while avoiding unacceptable flood risks.

Relevant Objectives

10.

To ensure effective use is made of urban land in meeting development needs.

13.

To seek ways to reduce flooding and its associated risks to people and property including ensuring development does not increase the risk.

15.

To ensure development contributes to sustainable transport choices and reduces the need to travel.

16.

To prevent further urbanisation.

17.

To support the retention of sufficient well located employment land to enable the maintenance of the local economy and to support redevelopment of well located land to meet business needs.

19.

To provide for the continued development of Staines as a focus for a mix of town centre uses including retail, leisure and employment and to improve access to the town centre.

20.

To maintain the role of the centres of Ashford, Shepperton and Sunbury Cross in providing local services.

Explanation

5.2

New development is required to meet the needs of the community for places to live and work, and to provide for the shopping, leisure and other facilities required. The draft Regional Spatial Strategy for the South East makes clear that the primary focus for development across the South East as a whole should be in urban areas. This is reflected at national level in the focus on use of previously developed land (PDL). Spelthorne lies at the inner edge of the Metropolitan Green Belt and its Green Belt has a critical strategic role as well as an important role locally in maintaining gaps between settlements and their separation from London.

5.3

The Green Belt is a key element in securing sustainable development in the wider area around London by containing the outward spread of the capital, preserving open land for the benefit of all and encouraging urban renewal. Maintenance of the Green Belt is reflected in national policy (PPG2), regional planning guidance and the Surrey Structure Plan. The existing Local Plan Green Belt Policy GB1 and associated designation of the Green Belt on the Local Plan Proposals Map is ‘saved’. Consequently new development will be on previously developed land.

5.4

The focus on urban areas means making effective use of land within urban areas for development. Therefore 100% of new housing should be on previously developed land. However, it is vital to ensure that development takes place in a sustainable way and does not mean sacrificing environmental quality or failing to provide for necessary services and infrastructure. Part of the urban focus is the need to maintain all major areas of employment development, which include the Employment Areas within existing town centres, and existing retail areas as well as seeking to provide for additional housing needs. Poorly located employment development sites in residential areas will be used for housing.

5.5

The Council’s Strategic Flood Risk Assessment (SFRA) shows that a large part of the Borough is at flood risk. This imposes a significant constraint on the use of some urban areas. The Council has carefully assessed the needs of the Borough in relation to the risks and government guidance (PPS25) in avoiding flood risk and how the risks to existing residents and businesses may be reduced.

5.6

Background studies on housing, employment and retailing have examined future requirements and how they can be met from within the existing urban area and the findings have been considered in the context of the SFRA. The Council is able to meet its housing requirements without building on land within Flood Zone 3 (1:100 flood risk area) except where the risks from flooding can be overcome. It can also meet future employment and retail requirements from within the urban area, again without unacceptable flood risks, through appropriate mitigation where necessary. Flood zones are defined in Table 2.

5.7

Strategic Policy SP1 also aims to ensure major traffic generating development occurs in accessible locations where it can be reached by a choice of modes of travel. This will assist in implementing measures aimed at reducing reliance on the car and avoid increasing the need for travel.

Strategic Policy SP1: Location of Development

The extent of the existing urban area will be maintained and provision for all new development will be made within it. Existing residential areas will be maintained and new residential development will only be allowed in Flood Zones 1 and 2 unless it can be demonstrated that flood risks can be overcome.

The overall amount of employment development will be maintained. Larger well sited Employment Areas will be retained and increases in employment development accommodated in those locations and particularly in Staines town centre. Poorly sited employment uses in residential areas will be redeveloped for housing.

Existing retail centres will be protected to meet future retail needs.

DETAILED POLICIES

Flooding

5.8

Flooding has implications for the Borough not only in terms of the constraint it places on the location of new development but also as an issue which sits with other ‘climate change’ related matters. For this reason it is referred to in both Strategic Policies SP1 and SP7. Detailed Policy LO1 on flooding is placed within this section because of its significant spatial implications. Policy LO1 deals with a wide range of actions to reduce flood risk and is presented in one comprehensive policy to convey clearly the Council’s approach.

5.9

A significant area of Spelthorne lies in the floodplains of the Thames, Colne (and related river system) and Ash. The only flood defences are very limited and are on parts of the River Colne system and the River Ash.

5.10

The Environment Agency Thames Catchment Flood Management Plan (Thames CFMP) (September 2006) confirms the above and sets out some ‘main messages’:

flood defences cannot be built to protect everything,
localised defences might be developed,
the ongoing cycle of development and urban regeneration is a crucial opportunity to manage flood risk,
land for future flood risk management will be identified and protected by authorities.

5.11

The Council’s Strategic Flood Risk Assessment (SFRA), December 2006, assessed all forms of flood risk in the Borough. It concluded that fluvial flooding (from rivers) poses the greatest risk to life and property. The study identified flood risk areas based on the flood zones identified in PPS25 and set out in Table 2. Flood risk was modelled using Environment Agency data. The Agency has subsequently updated its data through the Lower Thames Flood Risk Mapping Study, February 2008 for Zone 3b and Zone 3a flood outlines, and its Flood Map for England and Wales, December 2007, for Zone 2. These outlines are shown on the Proposals Map. The Council will use this data or any subsequent more up to date flood data in applying Policy LO1.

5.12

Flood Zone 3 affects over 2800 residential properties and large commercial areas including about half of Staines town centre. Removing the existing flood risk from people and property by relocating development is not a realistic option because of the enormous costs and lack of alternative land outside the flood risk area. A ‘sequential’ approach of ensuring new development is only in areas not at flood risk would on its own fail to deal with the risks faced by those already living or having businesses in flood risk areas. Rigid adherence to the sequential approach to new development would also not realise the opportunity identified in the Thames CFMP and PPS25 to use development as a way to help manage and reduce flood risk. It would also not ensure that the continuing role of Staines in particular, as a sustainable and accessible location for many facilities including as a major shopping centre, could be fully maintained to meet the needs of local residents.

5.13

A comprehensive approach to dealing with flooding and its risks has been followed to avoid adding to the risks to people and property and to seek to reduce the extent of flooding that would otherwise arise from doing nothing. This has included applying the sequential approach in PPS25 which aims to steer new development to Flood Zone 1 unless there are no reasonably available sites in areas of a lower probability of flooding that would be appropriate for the type of development or land use proposed. The approach does not allow residential development within Flood Zone 3 that would put people at risk.

5.14

Positive support is given to flood risk management measures. The Environment Agency is currently assessing what measures might be appropriate in its ‘Lower Thames Strategy’. These include possible flood alleviation channels and management/mitigation measures. However, flood channels are unlikely to be implemented until towards the end of the plan period at the earliest and therefore any potential benefits will not be taken into account in decisions on development proposals before full implementation of such works.

5.15

The policy also seeks to ensure the capacity of the floodplain is both preserved and, where possible, through appropriate development, increased and impedance to the flow of floodwater is, if possible, reduced. Redevelopment of existing developed sites in flood risk areas for less vulnerable uses will be supported where it achieves a reduction in flood risk through increased flood storage capacity and reduced impedance to flood water flow. The policy takes account of the impact of climate change by not permitting highly vulnerable uses in Flood Zone 2 and requiring any development in this zone to be flood resilient/resistant.

5.16

More stringent controls on development are made in Flood Zone 3b (referred to in PPS25 as ‘functional floodplain’). These are areas of generally fast flowing floodwater in major flood events where there are particular risks to people and property.

5.17

All applications covered by the provisions of the policy will require an appropriate Flood Risk Assessment. This includes in Zone 1 development on sites over 0.5ha, or for 10 dwellings or non-residential development of 1000m2 or more because surface water flooding from outside the floodplain can contribute to flood risk.

5.18

PPS25 categorises different degrees of flood risk by zones and identifies uses appropriate to each zone by level of vulnerability. Table 2 summarises these details and indicates what will be permitted or precluded from flood risk areas in Spelthorne in line with Policy LO1.

Table 2 - Degree of flood risk and appropriate use

Flood Zone	Degree of Flood Risk	Appropriate Uses
Zone 1	Low probability with less than a 1:1000 chance of flooding	No uses precluded on flooding grounds
Zone 2	Medium probability. 1:100 to 1:1000 chance of flooding	‘More vulnerable’ uses such as housing, ‘less vulnerable’ uses such as commercial uses and ‘water compatible’ uses such as open space
Zone 3a	High probability. Greater than 1:100 chance of flooding	‘Less vulnerable uses’ and ‘water compatible uses’
Zone 3b	Greater than 1:20 chance of flooding. Area of fast moving water and referred to as ‘functional floodplain’	Only water compatible uses

Policy LO1: Flooding

The Council will seek to reduce flood risk and its adverse effects on people and property in Spelthorne by:

supporting appropriate comprehensive flood risk management measures within or affecting the Borough which are agreed by the Environment Agency,

reducing the risk of flooding from surface water and its contribution to fluvial flooding by requiring all developments of one or more dwellings and all other development over 100m² of floorspace in the Borough to have appropriate sustainable drainage schemes,

maintaining flood storage capacity within Flood Zone 3 by refusing any form of development on undeveloped sites which reduces flood storage capacity or impedes the flow of flood water,

maintaining the effectiveness of the more frequently flooded area (Zone 3b) of the floodplain to both store water and allow the movement of fast flowing water by not permitting any additional development including extensions,

not permitting residential development or change of use or other ‘more vulnerable’ uses within Zone 3a or ‘highly vulnerable uses’ within Zone 2 where flood risks cannot be overcome,

supporting the redevelopment of existing developed sites in the urban area in Zones 3a and 3b for ‘less vulnerable’ uses where:

a minimum increase of flood storage capacity of 20% can be secured (all flood storage areas to be effective at all times throughout the lifetime of the structure/use and do not create unacceptable risks to people in times of flood),
it reduces impedance to the flow of flood water where there would be flowing flood water,
appropriate access for the maintenance of water courses is maintained,
there is no adverse impact on the integrity and effectiveness of flood defence structures.

requiring any development in Zones 2, 3a and 3b to be designed to be flood resilient/resistant,

requiring all development proposals within Zones 2, 3a and 3b, and development outside this area (Zone 1) on sites of 0.5ha or of 10 dwellings or 1000m2 of non-residential development or more, to be supported by an appropriate Flood Risk Assessment.

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