17 Climate Change and Sustainability

17.1.1 This section sets out the planning policies that will be applied to ensure that development in Central Bedfordshire is delivered in a way that contributes to the mitigation of climate change and embeds adaptation to the impacts of climate change in order to limit negative impacts.

17.1.2 The NPPF stresses that responding to challenges of climate changes is central to the economic, social and environmental dimensions of sustainable development, placing an emphasis on Local Planning Authorities to adopt proactive strategies to mitigate and adapt to climate change in line with provisions and objectives of the Climate Change Act (2008).   

17.1.3 As with the Environmental Enhancement Section, this section/chapter is underpinned by the Council's Environmental Framework.  This document summarises a range of local studies, assessments, strategies and guidance, and forms part of the technical evidence base for the Local Plan and is the supporting document for these policies. 

17.2 Planning for Climate Change

Climate change mitigation: Cutting the carbon footprint of new development

17.2.1 The Climate Change Act (2008) establishes a legally binding target to reduce the UK's greenhouse emissions by at least 80% in 2050 from 1990 levels. 

17.2.2 The Government's expectation set through the NPPF is that each local authority contributes to meeting this target through setting local requirements for the sustainability of buildings that are consistent with the Government's zero carbon policy, adopt nationally described standards, and promote energy from renewable and low carbon sources.

17.2.3 As such the Council will require all major developments  to submit a Sustainability Statement that clearly demonstrates the steps taken to minimise energy demand, and implement renewable and low carbon technologies to reduce carbon emissions from the proposed development by at least 10%.

17.2.4 The Council recognises the benefits of using the energy hierarchy in reducing energy demand and a fabric first approach, along with use of passive solar design is recommended before deciding on appropriate renewable and low carbon technologies. 

17.2.5 The Sustainability Statement will also set the strategy to address widely recognised issue of buildings not performing as designed (identified by Zero Carbon Hub as the performance gap), by confirming the proposed measures to ensure that new buildings achieve the energy performance intended at the design stage. 

Climate change adaptation: Water efficiency; flood resilience, subsidence and overheating

17.2.6 Climate change projections show that we will experience hotter drier summers, milder winters, and the associated extreme weather impacts of drought and flooding.

17.2.7 In 2017 the UK Climate Change Risk Assessment highlighted the need to take early action to mitigate the risks to the environment, the economy and to health, and to ensure that the UK can adapt to the changing climate. 

17.2.8 The Central Bedfordshire Local Climate change Risk Assessment (LCCRA) identifies flooding, overheating, water resources shortages, subsidence and impacts on the natural environment as risks that need to be planned for and managed.  These correspond with the 2017 National Climate Change Risk Assessment as priority areas for actions.

17.2.9 Adaptation to climate change is a dynamic and flexible process, with decisions that are made in the near term needing to have regard of the long lifespan of buildings and infrastructure.  This includes exploiting opportunities to adapt existing built areas, for example through maximising green infrastructure or by increasing the amount of urban greenery to help absorb floodwater and make buildings and open spaces more comfortable in hot weather. 

Making development resilient to the impacts of increased rainfall and drought

17.2.10 The design of new developments should reflect the increasing likelihood of periods of either drought or flooding, and consequently value water as a resource that can be stored in times of plenty for re-use in times of deficit.  All new developments will therefore be expected to address the issue of water scarcity.   

17.2.11 Consequently, all new development will be expected to achieve the higher water efficiency standard of 110 litres per person per day, as set by the Part G of the Building Regulations.  All commercial development will be expected to demonstrate how water usage will be reduced and the equivalent of the BREEAM 'very good' standard for water efficiency achieved.  Developments that will achieve high water efficiency standards going beyond the Building Regulations requirements and those that will include water harvesting and recycling will be look at favourably.  Measures that further promote water efficiency, such as grey water recycling and water butts, will be considered favourably.

17.2.12 Site scale adaptation measures, such as Sustainable Drainage systems are dealt with in Policy CC1, however on the individual building level, new developments are required to use simple rainwater harvesting (for example through provision of water butts, for external use wherever practicable. 

17.2.13 Flood risk at a site level is dealt with in Policy CC3, but it is important that where appropriate, buildings are designed to be more resistant or resilient to flooding and the impacts of flooding both now and in the future. 

Mitigating overheating and the urban heat island

17.2.14 Built up areas with minimal open green space may exacerbate the risks associated with the urban heat island effect, where heat absorbed by heavy man-made structures radiates at night increasing local temperatures.  This risk can be minimised by increasing green space, use of solar reflective materials and coatings as well as designing ventilation paths through which hot air can be replaced with cooler air from nearby green open spaces. Providing more natural drainage systems to enhance water surfaces in urban areas also has a greater cooling effect, whereas temperatures are higher in densely developed areas with little green space around them. 

17.2.15 The orientation of a building together with a proportion and positioning of glazing areas determine the level of transmitted solar gain.  This is particularly important where solar gain cannot be absorbed (for example by thermal mass) or extracted (through purge of mechanical ventilation) internal temperatures will increase. 

17.2.16 If managed properly, solar gain can be beneficial in reducing energy demand for heating, but equally it needs to be controlled to avoid build up of unwanted heat leading to overheating.  This can be controlled through careful orientation of the building and integration of effective solar control measures, such as brise soleil, external shutters, solar control glazing into a building and tree planting into landscape design. 

Managing risks through good design

17.2.17 The Sustainability Statement, to be submitted with applications for all major developments, will also demonstrate how the above climate change risks will be addressed through design, and will set out the strategy to minimise and manage these risks through the lifetime of the development. 

17.2.18 Good design can improve the quality of places and ensure they are adapted to a changing climate. Integrating green space and water within developments can provide many benefits for climate change adaptation including flood storage, localised climate cooling and habitat creation.  Developers should make use of the Council's Design Guide, which includes information on how to consider resource efficiency and climate change adaptation in the design of developments.

Supporting the use of sustainability standards for development

17.2.19 There are a number of well recognised standards for built environment for both residential and non-residential developments, such as BREEAM, PassivHaus and the Home Quality Mark.  The PassivHaus standard concentrates on energy efficiency, thermal comfort and indoor air quality while home Quality Mark and BREEAM covers much wider range of issues that affect sustainability of the development. 

17.2.20 The Council will look favourably at proposals that use these standards to demonstrate their sustainability and achieve higher standards than those prescribed by the Building Regulations demonstrated by certification of relevant scheme.

17.2.21 All major developments will be required to submit a post construction verification report to confirm that the development has been delivered to the approved specification.  The report should provide validation documents covering all aspects of the policy and provide as delivered evidence of compliance, for example as built energy calculations, BREEAM or PassivHaus certification, photographic evidence of implemented landscape or green infrastructure specification.

17.3 Large scale Renewable Energy

17.3.1 Increasing the amount of energy from renewable and low carbon technologies will help to make sure the UK has a secure energy supply, reduce greenhouse gas emissions to slow down climate change, and stimulate investment in new jobs and businesses.

17.3.2 The Renewables Capacity Study for Central Bedfordshire (March 2014) shows that a range of technologies may be suitable for this area and are effectively placed to deliver maximum local benefits, whilst at the same time contributing to the national need to increase low carbon energy generation. These include district heating schemes, photovoltaic energy, wind, locally sourced biomass and utilisation of landfill gas. 

17.3.3 The strategic allocation of sites set out in this plan presents significant opportunities for the provision of large scale low carbon energy schemes due to the concentration of significant demand in a single location, and the fact that they can be integrated into the development at the initial design stage providing scope for on site renewable energy generation.

17.3.4 The Written Ministerial Statement (June 2015) states that the Local Plan should identify 'areas as suitable' for wind energy development.   What constitutes a 'suitable area' (as opposed to a defined site) is based on a range of factors, including proximity to existing and future urban areas and infrastructure, grid capacity, radar and sensitive locations (such as historic buildings and sites and ecologically sensitive areas).  How this is interpreted in Central Bedfordshire will be set out in the Council's existing technical guidance notes for renewable energy, which has greater scope to take into account the latest information.   

17.3.5 In addition to this, the role of positive community engagement is key.  It is a fundamental requirement that developers engage with affected communities and stakeholders at the earliest opportunity, listen to their concerns and are able to demonstrate how these issues will be addressed.   Guidance on community engagement is also detailed in the Council's technical guidance for wind.

17.4 Flood Risk Management

17.4.1 Central Bedfordshire has been subject to flooding from several sources of flood risk, with the principal risk from fluvial sources, primarily located along the River Ivel corridor in the east, River Flit and River Hit in the centre and Clipstone Brook through Leighton Buzzard in the far west.

17.4.2 The area has experienced a number of historic surface water and drainage related flood events caused by factors such as insufficient storm and combined drainage capacity to poor surface water management. The Environment Agency maps and SFRA updated Flood Map for Surface Water (uFMfSW) mapping shows a number of prominent overland flow routes, following topographical flow paths of existing watercourses or dry valleys and local road infrastructure with some isolated ponding located in low-lying areas.

17.4.3 Incidents of historic groundwater flooding in Central Bedfordshire are thought to mostly be caused by the underlying geology of chalk and Lower Greensand, which allows water to pass to and from groundwater aquifers.

17.4.4 To minimise the risk created to people and property from new development the NPPF instructs Local Planning Authorities to direct development towards areas at the lowest risk of flooding, develop policies to manage flood risk from all sources, and take opportunities offered by new development to reduce the causes and impacts of flooding.

17.4.5 The suitability of development will be assessed by applying the Sequential Test. If, having passed the sequential test, development is proposed in areas at risk of flooding then developers will be required to demonstrate through the Exception Test that suitable compensatory storage and mitigation can be provided, and that the development will result in an overall reduction of flood risk on site and elsewhere.  Proposals for development in areas at high risk of flooding will be refused if other suitable sites are reasonably available in areas at lower risk.

17.4.6 A sequential approach to the layout of development should be taken at the site level and all development proposals must take account of existing and future flood risk (from all sources). They must demonstrate that the development will be appropriately flood resilient and resistant, safe for all of its users for the lifetime of the development, and that it will not increase flood risk overall. Opportunities to enhance green infrastructure and reduce flood risk by making space for water should be sought. 

17.4.7 Any protection and flood risk management measures that are required must be satisfactorily implemented and maintained. Where a development benefits from an existing or proposed flood defence scheme, the development should contribute towards the capital and/or maintenance of these defences over its lifetime.

17.4.8 Any proposed development located within an area protected by flood defences in a 'fair' or 'poor' condition, or where the level of protection is not to the required standard should be identified. 

17.4.9 In addition to the criteria set out in the NPPF,  the Council will require a site specific Flood Risk Assessment for new development within 20m of any watercourse, including those not shown on the Environment Agency Flood Maps, the Council's Strategic Flood Risk Assessment (SFRA), or within an area where are significant surface water issues.

17.4.10 Information from the SFRA should be used to inform the master planning of proposed major development sites, and any sites where a site specific Flood Risk Assessment is required. 

17.4.11 In areas identified at high risk by the SFRA, the Local Flood Risk Management Strategy (2014) or the Climate Change Adaptation Evidence Base Report (2012) the Council may specify requirements for mitigation measures such as controlling surface water run off to below the pre-developed rate.

17.4.12 The Local Planning Authority (LPA), Environment Agency and Lead Local Flood Authority (LLFA) should be consulted to confirm the level of assessment required and to provide any information on any known local issues.

17.4.13 When assessing sites not identified in the Local Plan (windfall sites), developers should use the evidence provided in the SFRA to assess and mitigate flood risk. Information about the Council's SFRA, as well as further material on national policy and local information on flood risk is set out in the Environmental Framework.

17.4.14 To minimise the risk from surface water runoff all new development should minimise areas of hardstanding and maximise the use of porous or permeable surface for infiltration, treatment and storage; for example by using permeable paving.  Sustainable drainage (SuDS) should be used on all new development as detailed through Policy CC5.

17.4.15 The likelihood and impact of flooding is expected to increase in the future due to the impacts of climate change and all new development must take this into account.  This can be done through using the appropriate allowances for peak river flows and rainfall intensities when determining risk to the site and the design of flood mitigation and drainage.  Likewise, new development will need to ensure people and property will remain safe from flooding for its lifetime Proposed flood mitigation and drainage infrastructure must be designed to handle intense or extreme storm events as well as residual risks associated with exceedance or system failure. 

17.4.16 At the individual property level, measures to improve resistance and resilience of buildings to flood risk will be required if buildings are situated in any flood risk area. In these areas new buildings should be designed and constructed in a way to prevent floodwater entering the building and damaging its fabric.  Where water may enter the building it must be constructed in such a way as to ensure the impact is limited with no permanent damage, the structural integrity maintained, and drying, cleaning, replacement and repair is facilitated. This includes setting of floor levels at an appropriate level for the current and future risk and the type and location of the development.

17.4.17 Wherever possible, opportunities should be taken to integrate the Council's objectives for flood risk management with the planning and delivery of new development to reduce the existing flood risk to developed areas and to achieve wider sustainability benefits of a site. This may include integrating or retrofitting surface water measures to replace and/or augment an existing drainage system in a developed catchment. The information provided in the SFRA should also be used as a basis for investigating potential strategic flood risk solutions, for example flood plain restoration, construction of new upstream storage schemes, and cross-boundary working.

17.5 Development close to watercourses

17.5.1 Development adjacent to, or which encompasses any kind of watercourse will be considered "close to a watercourse" and should provide opportunities to improve or enhance the water environment. This could be through river restoration, backwater creation, de-silting, de-culverting, in-channel habitat enhancement and appropriate removal of structures.

17.5.2 When designed properly, such measures can have benefits such as reducing the costs of maintaining hard engineering structures, reducing flood risk, improving water quality and increasing biodiversity. Social benefits may also be gained by enhancing green space and access to watercourses.

17.5.3 To provide the required detail to support a site's development hydraulic modelling may be required to inform more detailed Flood Risk Assessment studies, to follow Section 19 reports, or as part of the Level 2 SFRA.  If a watercourse or drain is shown on OS mapping but is not covered by a Flood Zone, this does not mean there is no potential flood risk and hydraulic modelling would be required at detailed site-specific level to assess the level of flood risk to the site.

17.5.4 Building adjacent to the banks of a watercourse has the potential to cause problems to the structural integrity of the banks and the building itself and can make future maintenance of the watercourse more difficult. Development must therefore be set back from the watercourse and an undeveloped buffer strip of no less than 9m should be provided between the top of the bank and any proposed development.

17.5.5 Historically, many natural watercourses have been altered in some way, for example artificially straightened or culverted. The act of culverting a watercourse tends to have mainly negative effects for flood risk management, access, maintenance and on the amenity and biodiversity value of the watercourses. The Council therefore expects existing watercourses to remain open wherever possible for both flood defence and environmental purposes.  This includes ensuring that existing natural drainage features will be retained wherever possible. In exceptional cases where culverting is unavoidable, the length involved should be restricted to a minimum, with the hydraulic and environmental design assessed, and appropriate mitigating enhancements to the surrounding environment included. It must also be demonstrated that other options have been thoroughly explored before culverting will be considered.

17.5.6 Inappropriate planting can lead to the erosion of banks and beds of a watercourse, increase maintenance costs, reduce ecological potential and may even lead to the spread of invasive alien species which are detrimental to the wider ecology of the area.  New development is required to ensure that any landscaping and planting will:

• Enhance of the drainage characteristics of a scheme;
• Stabilise areas that may be vulnerable to erosion;
• Enhance the visual appearance of the development; and
• Enhance the ecological potential of the local environment.

17.5.7 Through the above measures, development close to a watercourse should contribute to the achievement of good status and help avoid deterioration of water quality in line with the requirements of the Water Framework Directive (2000/60/EC). The Directive is considered in Policy CC6.

17.6 Sustainable Drainage and Surface Water Management

17.6.1 The Council expects that all developments will use Sustainable Drainage Systems (SuDS) and all development is required to provide a drainage strategy. Development proposals will be required to demonstrate the proposed standards of operation, construction, structural integrity and ongoing maintenance of the proposed surface water drainage system.

17.6.2 SuDS should be designed to slow, reduce and treat surface water flow by natural means. Where appropriate, every effort should be made to link SuDS into wider initiatives to enhance green infrastructure, improve water quality, benefit wildlife and/or contribute to the provision of the ecosystem service. SuDS should enhance water quality and biodiversity in line with the Water Framework Directive (WFD), 'end-of-pipe solutions' where runoff is directly discharged into a wetland or pond should be avoided, and source controls should be incorporated to improve water quality.

17.6.3 The Council's adopted local requirements for the use of SUDS are:

• Plan in SuDs from the start
• Replicate natural drainage
• Water re-use first
• Enhance biodiversity
• Focus on multi-functional uses
• Minimise carbon and waste in SuDS
• Design for easy access and maintenance
• Linked design through every scale
• Place making through SuDS design
• Surface conveyance over pipes

17.6.4 The Council's adopted local requirements for SuDS are set out in full in the Supplementary Planning Document 'Central Bedfordshire Sustainable Drainage guidance: May 2015'. This provides technical guidance including how the Council will assess development proposals; the information required to accompany planning applications; the local requirements for SuDS; and guidance for how SuDS can be designed for the local environmental character.

17.6.5 The level of detail that must be provided at each stage of the planning process is also set out. This enables informed assessment of development proposals, in order to ensure appropriate and specific flood mitigation and sustainable drainage measures are in place. Information and links to the SPD can be found in the Environmental Framework, along with further information on national policy and standards.

17.6.6 In addition to the above,  the design of surface water drainage must also comply with the 'Non-statutory technical standards for sustainable drainage systems' (March 2015, Ref: PB14308); PPG paragraph 80, Building Regulations Approved Document H, the Central Bedfordshire Design Guide and  other recognised best practice, including the Ciria SuDS Manual and BRE 365.

17.6.7 The design of surface water drainage must reflect site-specific circumstances such as topography, underlying geology and ground conditions, as these will inform the appropriate use of SuDS. The Strategic Flood Risk Assessment (SFRA) gives an indication of the constraints across Central Bedfordshire and is intended to be used at a preliminary planning stage. Detailed site investigations will therefore need to be carried out to assess the suitability of a site for different types of SuDS and their detailed design. Where site investigations indicate that infiltration SuDS are suitable, these must be designed to mimic natural infiltration as much as possible. Infiltration SuDS will not be appropriate in areas where surface water may be subject to contamination or where assessment demonstrates that risks to groundwater are unacceptable.

17.6.8 Discharge methods for surface water runoff should comply with PPG paragraph 80 and Building Regulations Approved Document H and should ease pressure of the development downstream by reducing the impact of surface runoff entering a receiving waterbody or drainage network. Brownfield sites are expected to provide a betterment of at least 30% of the existing discharge.

17.6.9 To ensure SuDS continue to function as designed for the lifetime of the development which they serve, new development proposals should include a 'management and maintenance plan'. This should set out arrangements for adoption (if applicable), maintenance activities, access to and responsibilities for public and private components of the system.

17.7 Water quality and the Water Framework Directive

17.7.1 The Water Framework Directive (WFD) and the Groundwater Directive recognises that development near water bodies can affect their quality and ecology. It establishes a legal framework for the protection, improvement and sustainable use of the water environment. This includes lakes, streams, rivers, groundwater and dependent ecosystems. The Environment Agency's River Basin Management Plans (RBMP) for the Anglian and Thames Districts are the lead policy documents that cover WFD matters in Central Bedfordshire, and place further constraints on new development in terms of its influence on the quality status of receiving water bodies.

17.7.2 Many of the watercourses in Central Bedfordshire already meet the 'good' overall WFD status including the Clipstone Brook, the River Ivel (upstream of Henlow) and the Ickwell Brook. However, the majority only meet 'moderate' overall status or less. It is important that developments aim to take positive measures to conform to the WFD, which can be impacted as a result of development, for example in terms of 'deterioration' in ecological status or potential. More information on water quality in Central Bedfordshire is provided by the Environmental Framework.

17.7.3 Development in close proximity or which discharges to a waterbody must carry out a WFD assessment demonstrating that it will not lead to deterioration in the overall status of the waterbody, or prevent future attainment of good status. Where there are no apparent waterbodies nearby, consideration should still be given to WFD objectives given that all water eventually makes its way into the river system.

17.7.4 Development will identify opportunities to enhance the quality of the water environment, for example by:

• Integrating SuDS and green infrastructure into new development;
• Managing and where possible reducing the risk of water pollution
• Reducing the effects of flooding and drought on water bodies, and the prioritisation of naturalistic flood defence over the provision of hard flood defences.
• Making modification to watercourses to restore 'natural' systems, including de-culverting, restoring or re-profiling rivers and naturalising river banks.
• Adopting water efficiency measures;
• Restoration of contaminated land.

17.7.5 Early consideration of the water environment will enable water quality aims and outcomes to be secured through the planning process. By integrating SuDS into new developments and redevelopments, and through using these in sequence, it is possible to minimise pollutants which may be generated by a development.  This in turn will help conform to the water quality objectives of the Water Framework Directive, as well as reducing flood risk. The design of SuDS is considered in Policy CC5.

17.8 Safeguarding the Environment and Development from Pollution

17.8.1 An important aspect of providing sustainable development is maintaining a healthy environment and protecting public health, wellbeing and amenity, through the control of pollution. Pollution can cause adverse health risks, damage the environment and interfere with amenity. It can also adversely affect neighbouring land uses, cause long term contamination and hinder regeneration.

17.8.2 Some development has the potential to harm the environment and impact on public health in a variety of ways, including the emission of pollutants to the air (including odour), water courses and soils, and the generation of noise, vibration, light, litter and pests. The Council will consider the possible polluting effects of a development proposal on aspects such as amenity and surrounding land uses and other receptors such as the effect on biodiversity. 

17.8.3 In addition to pollution, the NPPF makes it clear that all development should take account of ground conditions and land instability in order to ensure that sites are suitable for its new use and that any uses do not have any unacceptable adverse impacts on the natural and historic environment or human health.

17.8.4 The Council will seek to maintain sustainable and healthy environments through the careful consideration of development proposals which are likely to cause pollution or are likely to be exposed to potential sources of pollution. Proposals will be required to comply with the Central Bedfordshire Design Guide or any site specific Development Briefs or Masterplans. Where necessary the Council will use planning conditions and/or legal agreements to help limit the impact of pollution.