Sevenoaks District Local Plan Proposed Submission Version Regulation 19 Consultation (including Appendices 1-4)

Chapter 9 - Climate Change, Flooding and Healthy Communities


Supporting Evidence

  • Sevenoaks District Community Plan 2016-19
  • Sevenoaks District Health Deal 2015
  • Sevenoaks District Health Inequalities Action Plan 2015-2018
  • Kent Public Health Observatory Joint Strategic Needs Assessment
  • Kent Active Travel Strategy
  • Sevenoaks District Strategic Flood Risk Assessment 2017

Health, Wellbeing and Safety

9.1 National planning policy encourages local authorities to plan proactively for healthy, sustainable communities. The District has an ageing population, pockets of deprivation and a large proportion of residents living in rural areas. It is important that provision is made to ensure all residents have the opportunity to improve their wellbeing, reduce social exclusion and isolation, stay physically active and live healthier lives.

9.2 IMG_2898Sevenoaks District is overall one of the 20% least deprived districts/unitary authorities in England. Despite having low levels of deprivation on average across the District, there are some pockets of deprivation mainly in the north and rural areas amounting to more than 10% of the population. Data from the Index of Multiple Deprivation (2015) shows that some of the most deprived neighbourhoods in the District are located in the wards of Swanley White Oak and Swanley St. Mary's. Other wards with relative deprivation also include in Swanley Christchurch & Swanley Village, Edenbridge North & East and Fawkham & West Kingsdown. Opportunities to improve the wellbeing of the more vulnerable aspects of the community and reduce social exclusion will be sought and proposals supported.

9.3 Current population data shows that 21% (24,700) of the District's population is aged 65 and over and this proportion is expected to increase during the plan period. There is an increasing need to identify opportunities to improve the health and wellbeing of the older population through medical infrastructure, social, community and recreational opportunities.

9.4 Public safety is of paramount importance and everyone has the right to feel safe in the places they live, work and relax. We will work closely with the Health and Safety Executive, The Environment Agency and Kent Police to establish if additional measures should be included in the Local Plan to identify hazardous establishments, ensure risks to public safety are not increased and to take reasonable measures to prevent major incidents.

9.5 A Health Impact Assessment (HIA) is a useful tool in determining planning applications where there are expected to be significant or adverse impacts on health and wellbeing. HIA's help to achieve the sustainable development by finding ways to create healthy and active communities which can be shaped by the built environments which we live in.

Air Quality

9.6 Poor air quality is an issue in parts of the District, and there are 14 established Air Quality Management Areas (AQMAs). The AQMAs are cited alongside the strategic road network as well as within some of our town and neighbourhood centres (see SDC Air Quality Annual Report for full details):

  • Strategic road network: M20, M25 and M26
  • Other roads: A20, A25, A224 and A225
  • Town/neighbourhood centres: Riverhead, Sevenoaks, Swanley and Westerham


9.7 Road traffic is the main contributor to poor air quality and there is a high dependency on private vehicles to make journeys to key locations within the District (e.g. stations, shops and community facilities). Measures to improve air quality include reducing the need to travel, providing electric vehicle charging points and promoting alternative modes of transport including cycling. Secondary effects of these measures can also improve general health and wellbeing.


Policy HE1 – Health, Wellbeing and Air Quality

Proposals which support healthy living opportunities, promote social inclusion and improve community cohesion will be supported where they are in accordance with other relevant policies. These may include community based projects, projects to provide better public access to existing facilities and the improvement of public spaces.

Health, Wellbeing and Safety

To support healthy and safe communities new development should:

  • be located within easy access to services and facilities;
  • create opportunities for better active travel to promote physical health including provision for safe cycle and pedestrian routes;
  • be designed to minimise threats and improve public safety;
  • be designed to improve mental health and reduce loneliness and isolation.


Developments that reduce health inequalities and social exclusion will be supported.

A Health Impact Assessment, setting out the expected impact on health, wellbeing and safety, will be required for the following new developments, which are expected to have significant impacts:

  • All major housing developments over 10 units;
  • For non-residential developments containing any of the following uses:
    • Education facilities;
    • Health facilities;
    • Leisure or community facilities;
    • Betting shops
    • A5 Use (hot-food takeaways);
    • And for any other uses that could be considered to have a detrimental impact on physical or mental health (e.g. payday loan shops/vapour parlours/nightclubs)

Where unavoidable negative impacts on health, wellbeing and safety are identified, mitigation measures must be incorporated into the proposal.

Air Quality

The design and location of new development must take account of the need to improve air quality in accordance with the District's Air Quality Action Plan. Development in areas of poor air quality or development that may have an adverse impact on air quality will be required to incorporate measures to reduce impact to an acceptable level.

New development in areas of poor air quality will be required to incorporate measures in the design and orientation that demonstrate an acceptable environment will be created for future occupiers. Schemes where unacceptable impacts cannot be overcome by mitigation will be refused.

Climate Change

9.8 We are living in a changing climate. The UK Climate Change Risk Assessment 2017 stated that an increase in temperature will lead to increased risks to human health and wellbeing, to agricultural food productivity, public water supply, and natural assets, as well as intensifying flooding.

9.9 In 2009 the Government released the UK Climate Projections which set out the likely effects of climate change across the country up to the end of the century based on simulations from climate models. Within the South East, a changing climate is expected to cause an increase in the average summer temperatures leading to potential overheating, associated health issues and an increased need for cooling. It is also expected to cause an overall decrease in rainfall which will reduce the availability of water in an already water stressed area of the country.

9.10 New development will need to be designed to be resilient for the changing climate as well as seek to reduce IMG_0346its impact through mitigation measures.

The majority of the Government's proposed mitigation measures for development are set out in the Building Regulations but there are still ways in which planning can help.

9.11 Policies within the local plan have been written to ensure that new development has a minimal impact on the climate through high quality and careful design, reducing the need to travel, promoting walking, cycling and public transport opportunities, allocating development in sustainable locations, supporting and promoting low carbon technologies and protecting and enhancing blue green infrastructure. These mitigation measures also contribute to improvements in community heath and wellbeing, and air quality.

9.12 The Building Research Establishment Environmental Assessment Method (BREEAM) is an independent sustainability assessment method for non-domestic development. It has been widely used for many years to ensure new non-domestic development meets higher standards of sustainability. More detail can be found at

Flood Risk and Sustainable Drainage

9.13 Flood risk is from all sources of flooding including from rivers, directly from rainfall on the ground surface and rising groundwater, overwhelmed sewers and drainage systems and from other artificial sources such as reservoirs, canals and lakes. Development should avoid areas at risk of flooding. Development within a floodplain, is not only in itself at risk of flooding but, by reducing the amount of land available for flood water storage, or by impeding flows, can increase the risk of flooding elsewhere.Bough_Beech

9.14 There is already significant national and local guidance in place for flood risk, in the form of the NPPF and Practice Note. There is also local guidance provided by the Lead Local Flood Authority (LLFA). The Strategic Flood Risk Assessment (SFRA) carried out in 2016 for the District has identified current sources of flooding and also takes into account the impact of climate change. The main source of flooding, in Sevenoaks is identified as fluvial flooding, the main sources being the River Darent and River Eden, with other smaller contributors.

9.15 The report also identifies that the District has experienced a number of historic surface water/drainage related flood events which can be attributed to a range of sources including surface water run off. There are five reservoirs in the District which can also be a source of flooding. Ground water flood events have occurred in the District mainly due to high water table levels. The SFRA also identifies the Flood Zones that land falls under across the District.

9.16 In looking at the flooding and drainage evidence, guidance and legislation, the main issues identified for Sevenoaks District, in addition to existing policy and guidance includes:

  • The need to reduce surface water run-off from development.
  • The need to create space for flooding, including integrating green infrastructure in mitigation for surface water.
  • Looking at opportunities to work with natural processes to reduce flood risk. For example, this will include considering the construction of up stream storage schemes to protect urban areas down stream. This will involve partnership working with neighbouring authorities, organisations and water management bodies.
  • The need to reduce flood risk by naturalising the banks of development in particular for brownfield development, adjacent to water courses as much as possible.
  • SuDS should be seen as an opportunity to promote and protect Green Infrastructure and also enhance ecological and amenity value as they mimic the natural process of green field surface water drainage and help reduce surface water run off.
  • SuDS need to be considered at the early stages of development to reduce the risk of flooding particularly to third party land and to ensure they are intrinsic to site design.


9.17 Sustainable Drainage Systems (SuDS) can make a real difference to flood risk by managing the quantity of surface water run-off from development as well as moderate flow rates and prevent sudden water level rises following heavy rain. SuDS can significantly reduce harm to valuable water resources by retaining water within the local hydrological system as well as protecting water resources from pollution by filtering run-off. SuDS can form an integral part of both soft or hard landscaping and can contribute to the quality of green space for the benefit of amenity, in terms of the visual features and attractiveness of a place, as well as recreation and wildlife. SuDS may also allow new development in areas with critical drainage problems whereby existing drainage systems are close to capacity, thereby enabling development within existing urban areas. It should be noted that the cumulative impact of small sites can have a significant impact on flood risk, and therefore, the inclusion of SuDS is essential on both small and larger developments.

9.18 SuDS are designed to control surface water run-off close to where it falls and mimic natural drainage as closely as possible. SuDS also provide opportunities (in line with the NPPF) to:

  • Reduce the causes and impacts of flooding;
  • Remove pollutants from urban run-off at source; and
  • Combine water management with green space with benefits for amenity, recreation and wildlife.


9.19 Source Protection Zones (SPZ) for groundwater provides a third of drinking water in England and it is crucial these zones are looked after to ensure water is completely safe to drink. Developments should include robust protection measures and consideration of drainage design and ground disturbance to minimise potential impacts on groundwater quality and reduction in the availability of groundwater sources.


Policy CC1 – Climate Change, Flooding and Water Management

Climate Change

We will contribute to reducing the causes and effects of climate change by promoting best practice in sustainable design and construction to improve the energy and water efficiency of all new development. We will support climate change mitigation and adaptation measures, including:

  1. Appropriate small scale community led renewable energy schemes;
  2. Small scale renewable and low carbon technologies where appropriate (e.g. solar panels);
  3. Reducing the need to travel by sustainably locating new housing and supporting the level of services and facilities;
  4. Promoting sustainable design measures for new developments including passive solar design;
  5. Utilising opportunities for decentralised energy and heating where appropriate;
  6. Protecting existing green spaces, trees and vegetation to absorb carbon dioxide, provide summer shading, retain and create habitats and reduce surface water runoff; and
  7. Resilient drainage design which includes a climate change allowance.


All new non-domestic development (including conversions) must achieve BREEAM "Excellent" standards. Applicants will be expected to provide certification evidence of the levels for BREEAM at the design stage and on completion of development.

Water Management

Development proposals must have regard to the Water Framework Directive, the Thames River Basin Management Plan and management plans for the River Darent and Eden.

New development must not deteriorate any existing watercourses and should actively enhance the natural function and habitats of watercourses wherever feasible. This should include:

  • Providing adequate natural buffers to watercourses to prevent damage;
  • Reinstating natural buffers where this has been previously lost;
  • Seeking opportunities to unculvert watercourses and incorporate them into the water management scheme;
  • Restoring damaged waterbodies.


Any necessary crossing points over rivers and watercourses should utilise clear spanning bridges where possible to allow natural river processes and wildlife to continue to utilise the river corridor.

Major development schemes will be expected to undertake a Water Framework Directive Assessment setting out the existing ground and surface water baseline and the potential impact of the new development.

All new schemes should be designed to promote water efficiency and are encouraged to achieve a mains water consumption target of 110 litres per head per day.

Flood Risk

Residential development must avoid, and non-residential development should avoid, areas at risk of flooding and no development should take place in Flood Zones 2 and 3 without agreement from the Environment Agency. Where new development schemes included areas for flooding these should be designed to maximize wildlife and habitat opportunities including in channel habitats.  

Development on sites larger than 1ha in Flood Zone 1 must be subject to a Flood Risk Assessment (FRA) in accordance with the Council's Strategic Flood Risk Assessment, National and Local guidance and the Lead Local Flood Authority drainage guidance and policy statements. The FRA should include the requirement for any mitigation measures and where relevant, the assessment should also address the risk of flooding from surface water, groundwater and ordinary watercourses. Where there is evidence that water from these sources ponds or flows over the proposed site the assessment should state how this will be managed and what the impact on neighbouring sites will be.

Measures identified to mitigate the effects of flooding shall be installed and maintained at the applicants' own expense or put into a management company to ensure their long term retention, maintenance and management. Other flood resilient and/or resistant measures may also be required, and their provision will be informed by the findings of a submitted Flood Risk Assessment.

Sustainable Drainage

All developments must incorporate natural flood alleviation measures and sustainable drainage provision which mimics natural flows and drainage pathways and ensures that surface water run-off is managed as close to its source as possible.

Any drainage scheme must manage all sources of surface water, including exceedance flows and surface flows from off-site, provide for emergency ingress and egress and ensure adequate drainage connectivity. It will not be acceptable for surface water run-off to enter the foul water system.

Sustainable Drainage Systems (SuDS) or other appropriate measures should:

  1. Maintain public safety;
  2. Provide sufficient attenuation to surface water flows as appropriate;
  3. Ensure that there is adequate treatment of surface water flows, such that there is no diminution in quality of any receiving watercourse;
  4. Ensure protection of groundwater; and
  5. Provide or enhance wetland habitat and biodiversity where possible.


Approval of the design, phasing, long term management and maintenance of SuDS will be required prior to the development commencing. All development should be in accordance with Kent County Council guidance for SuDS.


Performance Indicators for Climate Change, Flooding and Healthy Communities

Number of planning permissions granted contrary to Environment Agency Advice on Flooding (No new development to be completed contrary to Environment Agency advice)

Number of planning permissions granted contrary to Lead Local Flood Authority (KCC) advice on SuDS (No new development to be completed contrary to KCC SuDS advice)

Large Scale Renewable, Decentralised and Combined Heat and Power Schemes Installed by capacity and type (Monitor the number of schemes completed)

Changes in Air Quality Management Areas (Net improvement in air quality)

Health Impact Assessments (HIAs provided on all completed major housing developments over 10 units and non-residential developments and completed development in the following uses:

Education facilities;

Health facilities;

Leisure or community facilities;

Betting shops

A5 Use (hot-food takeaways);

And for any other uses that could be considered to have a detrimental impact on physical or mental health (e.g. payday loan shops/vapour parlours/nightclubs)