Briefing Paper: Climate Change Adaptation in Brighton and Hove

Climate Change Adaptation in Brighton and Hove

 

Andrew Coleman

The following is a summary of a longer and comprehensive report prepared by Andrew for Climate:Change. The full text (highly recommended) can be downloaded as a pdf here. See the full report for references and links.

 

This review summarises current frameworks for assessing progress in adapting to climate risks, and reviews the Brighton and Hove City Council (BHCC) adaptation strategy. The key questions are: 

  1. Is the core analysis right in its own terms?

  2. Are the measures proposed in response to the analysis good enough?

  3. Has the strategy taken a sufficiently long view and linked to changes in B&H?

The review is supportive of the overall effort made in the adaptation strategy. However, it makes eight recommendations related to the planning risk and vulnerability assessment (RVA) process (Box 1), and nine recommendations related to the Climate Adaptation Action Plan (CAAP) (Box 2).

Box 1

Recommendations related to the adaptation planning process in Brighton and Hove

Box 2

Recommendations related to the Climate Adaptation Action Plan

 

Climate risks, adaptation and resilience: from ‘bounce back’ to ‘bounce forward’

The UN Intergovernmental Panel on Climate Change (IPCC)’s 6th Assessment Report in 2022 pointed out that global warming, reaching 1.5°C in the near-term, would cause unavoidable increases in multiple climate hazards and present multiple risks to ecosystems and humans.  For 127 identified key risks, assessed mid- and long- term impacts were up to multiple times higher than currently observed. And the IPCC argued that climate change impacts and risks were becoming increasingly complex and more difficult to manage.

Risk from long term and short term changes in the climate depend on several factors. The UN uses the components of ‘hazard’, ‘vulnerability’ and ‘exposure’ to break down risk. To take flood risk as an example:

  • Hazard: would include the depth, speed, duration, composition of floodwater.

  • Vulnerability: would include the type of person or ecosystem affected.

  • Exposure: would include the presence of people and ecosystems.

The United Nations (UN) defines adaptation as ‘adjustments in ecological, social or economic systems in response to actual or expected climatic stimuli and their effects.’

In its National Adaptation Programme, the UK government describes adaptation as: ‘actions that protect us against the impacts of climate change. This includes reacting to the changes we have seen already, as well as preparing for what will happen in the future.’ The document gives  examples as: building new flood defences to protect against rising sea levels; planning for more green spaces in urban areas to help keep them cool; and building infrastructure that can withstand expected climate impacts such as extreme heat and flooding

Resilience is a key concept. However, Lonsdale et al suggested that definitions of ‘resilience’ are contested and fluid when applied to UK climate policy, noting that resilience has broad and narrow, place-based and operational aspects. Rather than an ability to ‘bounce back’ from erosion or flooding, they suggested resilience as a progressive way to ‘bounce forward’, requiring: legitimate and inclusive mechanism(s) to engage across the whole of society; an informed public with access to accurate, salient information; and an enabling environment with clear coordination and courageous leadership.

 

Committee on Climate Change assessment of UK adaptation progress

The independent Committee on Climate Change (CCC) uses the methodology in Figure 1 to define the urgency of risks.

Figure 1: Urgency Scoring Framework.

 Source: Climate Change Committee

 

The highest priorities for the UK are shown Figure 2:

 

Figure 2: UK Climate Adaptation Priorities

 Source: Climate Change Committee

In its latest report to Parliament on progress in adapting to climate change, the CCC assessed sector adaptation progress outcomes and considered delivery and implementation (outer rings), as well as the existence and adequacy of policies and plans (inner rings). See Figure 3. None of the sector outcomes are making good progress on delivery and implementation and there are limited policies and plans for most sector outcomes.

 

Figure 3: Sector progress in adapting to Climate Change

Source: Climate Change Committee

 

Adaptation in Brighton and Hove

The BHCC Transport and Sustainability Committee considered a report in February 2024 (from Pg 141 here). It referred to a Climate Risk and Vulnerability Assessment (RVA) carried out by Arup with an Adaptation Action Plan, setting out prioritised actions over 1-2, 2-5 and 5+ years, an Urban Heat Island Assessment (UHIA) showing the parts of the city likely to be affected by increased summer temperatures (especially at night), and a more detailed version of a Vulnerability Assessment.

The Risk and Vulnerability Assessment

The RVA reflected input by internal Council and external stakeholders, notably the Greater Brighton Infrastructure Panel, local businesses, NHS, Southern Water, Network Rail, emergency services, the bus company and The Aquifer Partnership. The Committee Report refers to monthly meetings of an ‘adaptation oversight group’ to take the work forward.

The largest risks identified in the report were:

  • High temperatures

  • Water scarcity

  • Aridity

  • Increased seasonal soil water saturation

  • Sea level rise

  • Groundwater, coastal and surface water flooding

  • Coastal erosion

  • Slope and embankment failure

  • Extreme weather events

Arup used its proprietary Uheat modelling to demonstrate the Urban Heat Island (UHI) effects in the city. UHI describes the phenomena of urban areas being warmer at night than surrounding rural areas as the buildings and hard infrastructure absorb heat during the day and emit it more slowly than vegetation at night. UHI is important because high temperatures can lead to heat stress and increase excess death rates, particularly among the elderly and people already ill.

The modelling produced results for 2022.  An example is shown in Figure 4 below. The lighter colours show areas where the temperature was higher or the UHI Intensity (difference between rural and urban areas) was higher. The analysis shows that peak and average temperatures are higher where there is higher density of built development, more people and infrastructure emitting heat, and less greenery to absorb heat - in the city centre and in parts of Hanover, between Seven Dials and Brighton Station, and central Hove. Cooling breezes near to the sea and higher slopes tends to reduce temperatures.

 

Figure 4: Surface temperatures across Brighton and Hove, aggregated over summer 2022 period

 Source: Arup and BHCC

The methodology of Arup’s Vulnerability Study is based on the identified risk factors used by the CCC assuming 2 degrees C and 4 degrees C of warming by the end of the century. Using national and local data, it assesses risk using likelihood and impact as the main variables currently, in the 2050s, and in the 2080s. Multiplying likelihood by impact gives an overall risk rating with a corresponding Recommended Action.

See Table 1 below for the way the risks are assessed and translated into the BHCC’s Corporate Risk Management Framework. ‘High’ Risks have a recommended action of ‘Immediate action required and need to escalate to the management level above’.

Table 1: How risks are graded.

Source: Arup and BHCC

Risks in the national register that were not considered relevant to the City were scoped out of the assessment. The remaining risks are divided into sections according to the receptor of the risk:

  • Natural Environment and Assets

  • Infrastructure

  • Health, Communities and the Built Environment

  • Business and Industry

The risks are summarised in the Appendix to this note.

The Climate Adaptation Action Plan

The Climate Adaptation Action Plan (CAAP) identifies:

  • Completed and/or ongoing actions, related to climate adaptation, which have been identified from other BHCC strategies and action plans, including four detailed case studies

  • Recommended actions identified to adapt the BHCC natural environment, infrastructure, people, and businesses to a changing climate

  • Organisation(s) that may be able to lead on the implementation of the action(s)

  • An indicative timescale for delivery of the action(s) (short-term (<2 years), medium-term (2-5 years), or long-term(5+ years)); and

  • An indicative cost for delivery of the action(s) (high (>£80k), medium (£25k-£80k), or low (<£25k)).

The completed and ongoing actions include the coastal defence strategies completed and ongoing with the Environment Agency and other partners, the Downland Estate Management Plan, managing air quality and promoting tree planting and biodiversity in public open space etc.

The 18 Recommended actions include 7 cross cutting measures including Priority Actions of creating a cross-Council adaptation strategy and appointing a dedicated communications adaptation specialist within 2 years, as well as building on accumulated expertise within the Council and external stakeholders.

The other 11 Actions address risks in the four sectors used in the Vulnerability Assessment: Natural Environment; Health, Communities & the Built Environment; and Business. Priority Actions are identified for the following sectors:

  • Natural Environment: Develop and implement a green-blue infrastructure plan [within 2 years, Medium cost]

  • Business and Industry: Co-develop a climate adaptation toolkit [2-5 years; High Cost]

No Priority Actions are identified for Infrastructure or Health, Communities & the Built Environment sectors, but actions include using the council’s convening powers and knowledge of future development requirements to influence infrastructure providers’ climate adaptation activities, embedding climate adaptation into planning policies, considering retrofitting Council buildings, implementing drinking water fountains, and planting schemes.

Next steps identified include:

  • Engaging with key decision makers across the city, including establishing an Adaptation Working Group

  • Establishing governance and delivery model within the Council

  • Developing monitoring and evaluation of the Climate adaptation action plan

  • Identifying costs of and funding sources for adaptation.

 

Observations and Recommendations on the Risk and Vulnerability Assessment, UHI Assessment and Adaptation Action Plan

There follow some observations and recommendations (underlined), first on the analysis, then on the action plan:

On the analysis

1.      First, the approach of following the 2021 UK Climate Risk Assessment sector headings as a basis for the city’s is logical. In some cases, the national risk has been applied to Brighton and Hove, perhaps because of lack of local data or assessment of risk.

Data gaps could be more clearly flagged and ways identified to fill them.

The RVA ‘scopes out’ some climate risks that may be relevant to Brighton and Hove. It is reasonable to omit some risks which are clearly irrelevant to the city or outside its control or influence, but some are potentially relevant, for example: opportunities from new species colonisations in terrestrial habitats (eg locally important butterfly species); risks to forestry from pests, pathogens and invasive species (eg Ash dieback, Dutch elm disease or other pathogens); risks to bridges and pipelines from flooding and erosion (eg risks to sewers from additional rainwater); or risks to the viability of coastal communities from sea level rise (eg Brighton Marina)

The RVA should be regarded as a ‘living document’ and risks should be reviewed annually.

2.      Second, The RVA methodology is unclear in how risks were quantified and compared with each other, which makes it difficult to judge the relative risks of say, surface water flooding v overheating. Using a ‘decision tree’ such as the one used by the CCC would help to clarify the process for determining likelihood and magnitude of a risk.

The RVA methodology should be explained in more detail, include quantification where possible and made publicly accessible.

3.      Third, the information used to inform risks does not consistently consider how risks may change in future. For example, risks from coastal flooding appear to be assessed on current flood risk maps, not the Strategic Flood Risk Assessment carried out to support the City Plan Part Two in 2021, that models flood risk into the 2080s. This is significant because both Shoreham Port and Brighton Marina are identified in the current City Plan as Opportunity Areas where major housing development is planned, but where public funding to maintain and improve flood defences is not guaranteed. Risks to health from surface water and groundwater flooding also seem to be based on current risks, except for risks to cultural sites where an allowance has been applied to take account of future increases in heavy rainfall.  

 4.      Fourth, some current adaptation policies and actions are referred to eg coastal defence policy to ‘hold the line’ and Southern Water’s Drought Management Plan, while for many risks, no current adaptation actions are considered directly.  Where current adaptation measures are considered, there is no assessment of their effectiveness or if they are likely to continue into the future.

Future iterations of the RVA should consider future risks where information and modelling exist and take adaptation actions into account. Where risks and future adaptation is uncertain, this should be clearly stated, and the level of certainty estimated.

5.      Fifth, all risks identified as ‘high’ are coded red, which translates to ‘Immediate action required and need to escalate to management level above’ in the Corporate Risk Management Framework. While the overall risk rating is realistic, there are 17 red risks within the RVA, and the challenges of taking immediate action on all will be significant.

The RVA should attempt to prioritise risks within the broad categories which can inform prioritisation of actions in the CAAP.

6.      Sixth, on non-climate risks, the RVA does refer to increased health risks from rising temperatures, including because of existing health inequalities. However, it does not consider sources of information about population trends which may exacerbate climate risks. Perhaps the most obvious is population increase. While population increase in the city has been lower than the England or SE average, the Government is proposing that the average annual indicative housing need for the city is 2435 units. This number may be negotiated down or up as the City Plan is revised, but suggests that there will be more people potentially at risk from climate change and more stress on infrastructure needed to reduce climate risks (such as water availability and sewers).

The RVA should make clear which non-climate risks are included and, wherever practical, include in future versions.

7.      Seventh, Brighton & Hove's population is projected to get older. Older people are more susceptible to health risks (generally) and to high temperatures specifically. By 2030 the total population of residents aged 58 or older is projected to increase by 20% (11,500 people), while those aged 57 or younger is projected to decrease by 0.1% (300 people). By 2030, ‘baby boomers’ will be in their eighties, contributing to an increase in the population of those aged 75 or older of 19% (3,600 people).  While the population is healthier in many respects than the England and SE averages, the healthy life expectancy is declining, there are significant differences between parts of the city in life expectancy and healthy life expectancy, with some having above average levels of mental health issues and higher rates of suicide death and lifestyle-behaviours related health issues .

RVAs should be developed for parts of the city that are likely to be particularly adversely affected by current and future climate risks because of their deprivation / age / health profiles.

8.      Eighth, the UHIA is a very valuable resource to illustrate likely effects of the changing climate on heat in different parts of the city. However,  Arup’s UHEAT modelling does not take into account detailed air flows across the city, solar radiation, small 3D features, heat from buildings or transport or impacts of cooling already in place, humidity or other microclimatic factors – more detailed modelling and taking vulnerability into account would be required to show this.

Arup should be asked to identify which areas of the city or types of development are likely to be particularly affected to enable targeted detailed modelling to be considered.

On the Climate Adaptation Action Plan and the Council’s proposed programme

The CAAP sets out a detailed programme of work which has indicative costings and timescales in 18 Actions, including 4 Priority Actions and 7 cross-cutting Actions. The commitment to create a cross-cutting, Council-led adaptation programme led by a named individual is welcome.

1.      First, are the ‘Priority Actions’ the right priorities? The 4 Priority Actions are:

Action 1: Develop a council-led programme for climate adaptation

Action 7: Create a role for a dedicated specialist to oversee creation and implementation of a communications & engagement plan.

Action 8: Develop and implement a green-blue infrastructure plan

Action 18: Co-develop a climate adaptation toolkit to help local businesses.

It is noticeable that there are not Priority Actions in the Infrastructure and Health, Communities and Built Environment sections of the CAAP, despite the RVA indicating there are High Risks in these sections.

Review the need for Priority Actions in the Infrastructure and Health, Communities and Built Environment sections of the CAAP.

2.      Second, are the cross-cutting Actions comprehensive? The 7 cross-cutting Actions are welcome, particularly the Priority Action of creating a Council-led and Council-wide Adaptation Programme. However, they do not appear to include:

  • Any reference to the requirement to regularly review progress of the risk assessment or CAAP, including no regrets and low regrets adaptation options, low likelihood/high impact options, avoiding ‘lock-in’ and adaptive management opportunities.

  • Which member-led body provides oversight.

  • Whether Council reports will include a ‘Climate Considerations’ (not just net zero) section.

  • Any local equivalent of the Climate Change Committee to act as a ‘critical friend’.

  • Easily-found links to the RVA, UHI Assessment and CAAP on the Council’s website. They are not on its’ Climate Hub’ (Climate action (brighton-hove.gov.uk)) and appear to be only accessible found from the Committee page.

  • A Climate Assembly – which the previous Council used to engage people other than ‘the normal suspects’ in climate policy development. It could help to develop a community-led vision of an adaptable Brighton and Hove – a positive ‘bounce-forward’ approach.

  • Reference to the Local Government Association-developed Local Climate Adaptation Tool (LCAT), which is an evidence-based online resource that can be used to educate organisations and communities about climate adaptation risks, evidence and adaptations.

 The governance of climate adaptation activity in the Council should be clearer and adopt a similar approach to national models. It could include a greater element of community involvement of setting objectives, priorities, reviewing progress and encouraging community involvement.

3.      Third, are the actions for the Natural Environment realistic? The Priority Action (no.8) for the Natural Environment is to develop and implement a green-blue infrastructure plan. The risks it addresses are stated as N1 H1 H3 H7 I2. However, it would also help to address risks N4, N6, I8, H10, B1, B3. (See Appendix for description of risks). This indicates that perhaps the full value of CAAP is not being realised.

All Actions in the CAAP are reviewed to ensure that they apply to all relevant risks

It is worth noting that Southern Water is also planning the widespread rollout of Sustainable Drainage Systems (SuDS) to reduce stormwater discharge into the sea. Its (draft) Cleaner Rivers and Sea Plan identifies the Marine Drive Sewage Pumping Station as being a source of discharges and proposes the retrofit of SuDS throughout the catchment (most of Brighton and Hove, all Telscombe Cliffs and Peacehaven) between 2025-2030. This would entail an estimated £135.58m of investment, an estimated retrofit of 297.4 hectares of impermeable land in the area (approximately 12 Preston Parks or 16 Hove Parks), by installing SuDS (e.g. planting trees, installing raingardens, etc.) and may include the installation of at least 22521 household water butts and similar solutions for businesses and public buildings (Southern Water, 2024). In the west of BHCC, wastewater drains to Shoreham Wastewater Treatment Works. Here, Southern Water estimate it needs to manage approximately 25.8 hectares of impermeable land in the area, by installing sustainable drainage systems (SuDS) (e.g. planting trees, installing raingardens, etc.) in 2025-30. This may include the installation of at least 1849 household water butts and similar solutions for businesses and public buildings. 

There are clear advantages to including Southern Water as a stakeholder.

The case study of Wild Park Rainscape and other SuDS projects (specifically Carden Avenue) also demonstrate that retrofitting SuDS will be a longer and more expensive undertaking than envisaged in the CAAP. The Carden Avenue SuDS took approximately 3 years to plan, design and implement and cost approximately £237,000. A large amount of effort was spent persuading local residents of their value in reducing surface water flood risk. The Wild Park Rainscape is a £1.7m project. As the Lead Local Flood Authority, the Council has significant role to play in setting standards for SuDS and gearing up developers, architects, designers, planners and landowners for the possible removal of the ‘right to connect’ to surface water sewers.

As highway authority and a major landowner, the Council can uniquely influence how surface water flows across highways and other land, including designing for extreme events.

The large scale retrofit of multi-functional SuDS could be used as an opportunity to also increase biodiversity, which has the potential to attract funding from private developers that now need to achieve at least 10% biodiversity net gain.

Action 9 to restore biodiversity includes welcome actions, but it is suggested that the timescale for achieving this (Medium – 2-5 years) is unrealistic, given the depth of the climate and biodiversity crises, the likely resources available (estimated at £25-80000) and the length of time it will take for biodiversity to recover.

 Action 9 to restore biodvisersity is reviewed to identify if timescales and resources are realistic.

Action 10 refers to maintaining the ‘hold the line’ coastal management option into the long-term using artificial and natural management approaches. A BHCC Committee report in 2019 estimated the cost of maintaining the western part of the coastline (Shoreham Port to Brighton Marina) to the Council at £6.3m. The cost of the eastern part (Brighton Marina to Saltdean) is unknown, although the RA acknowledges that it may be more difficult to justify public expenditure on this section of the coastal defences. In fact, the latest Shoreline /Management Plan (SMP) identifies the ‘placeholder’ action for the long term (2055-2105) as ‘Managed Realignment’.

At a more fundamental level, Sayers et al studied the feasibility of the ‘hold the line’ and other policy approaches, taking into account climate change projections and probable development pressures and concluded that in many places the ‘hold the line’ approach was technically and financially unfeasible.

This suggests that the implications, and costs of maintaining ‘hold the line’ – including the visual appearance of hard defences and likelihood of ‘coastal squeeze’ of rare coastal habitats need to be reconsidered and opened to greater public debate.

 

Action 14’s commitment to embed climate adaptation into planning regulations and policies is welcome, although it is a legal requirement. The review of City Plan Part One provides a timely opportunity to strengthen consideration of current and long term (into the next century) climate risks and opportunities, including avoiding maladaptation policies such as directing significant new development to areas at highest risk of groundwater, surface water and coastal flooding (which the current City Plan does) and requiring climate adaptation and biodiversity net gain in all new developments.

The City Plan revision should take a more robust approach to climate adaptation.

Action 16 refers to promoting public drinking water facilities, and warm and cool spaces, all year round. It is worth recognising that urban environments can be adapted, not just by introducing more street trees, green roofs and walls but also artificial shading (see Figure 6 below) which could be targeted in places most at risk of overheating with fewest green spaces (such Hanover and North Laine).

Figure 6

Temporary street shading erected in Silves (Portugal) and Buis (France)

Source: Author

BHCC to explore feasibility of erecting temporary shading in areas particularly ar risk of overheating in heat waves.

Conclusion

The identification of climate risks, urban heat island effect and the creation of a Climate Adaptation Action Plan is very welcome. The methodology used to create this initial work is broadly sound. There are some gaps and uncertainties in the in the RVA which should be addressed. The CAAP will need to be kept up to date and adaptable itself to changing circumstances, including the climate, population growth and changing health, deprivation and age profiles. The RVA and CAAP would benefit from improvements to methodology and wider community input.

____________

Andrew Coleman, is a Senior Lecturer on the MSc Town Planning degree at the University of Brighton, including module leader for the Sustainable Urbanism in Coastal Communities module, and an independent planning and environmental consultant. He is a Fellow of the Royal Town Planning Institute, Royal Geographical Society and Higher Education Academy. He was formerly a Senior Advisor in the national Sustainable Places team at the Environment Agency and has worked as an environmental planner in a variety of public and private sector roles. He is a member of the BHCC Local Access Forum and a local representative for the environmental charity Surfers Against Sewage. The views expressed in this paper are personal.


Perspective pieces are the responsibility of the authors, and do not commit Climate:Change in any way. Guest posts are published to explore issues or stimulate debate. Comments are welcome.

 

Appendix

Summary of risks from the Vulnerability Study

The following risks to the natural environment are regarded as high currently and in the future:

N1 – Risks from High Temperatures to terrestrial species and habitats from changing climatic conditions and extreme events, including temperature change, water scarcity, wildfire, flooding, wind, and altered hydrology (including water scarcity, flooding, and saline intrusion) - Warmer summers and more frequent hot days are expected to have a short-term impact to habitats, becoming more long-term as high temperatures becoming increasingly sustained.

N4 – Risk from seasonal aridity and wetness to soils from changing climatic conditions, including seasonal aridity and wetness – high risk at national level. Extreme weather can exacerbate soil erosion

N6 – Risks from High temperatures + Water Scarcity and opportunities for agricultural productivity from extreme events and changing climatic conditions (including temperature change, water scarcity, wildfire, flooding, coastal erosion, wind, and saline intrusion) e.g. heat stress to livestock and crop failure and/or reduced crop yields

The following risks to the natural environment are regarded as significant currently and high in the future:

N1 – Risks from water scarcity to terrestrial species and habitats from changing climatic conditions and extreme events, including temperature change, water scarcity, wildfire, flooding, wind, and altered hydrology (including water scarcity, flooding, and saline intrusion) - reductions in water availability and aquifer storage/recharge can cause calcareous and woodland habitats etc to struggle

N16 – Risks from High Temperatures to marine species and habitats from pests, pathogens, and invasive species - most projections indicating increases of between 0.2°C and 0.4°C per decade, but with regional differences. In addition, other stressors, including pollution incidents such as sewage spills, ocean acidification and changes in salinity levels due to stratification and modification of currents, are likely to continue, increasing the vulnerability of marine organisms.

N17 – Risks from High Temperatures to coastal species and habitats due to coastal flooding, erosion, and climate factors. Coastal species may not survive at the really high temperatures expected although urban heat island effects are less at the coast.

N14 – Risks from High temperatures to marine species, habitats, and fisheries from changing climatic conditions, including ocean acidification and higher water temperatures. High temperatures can drive ocean acidification, which can negatively affect maritime species and habitats by dissolving shells and skeletons made from calcium carbonate (affecting sea snails and oysters). Increasing water temperatures are already globally affecting maritime species and habitats, causing loss of breeding grounds.

The following risks to the natural environment are regarded as moderate currently and high in the future:

N2 – Risks from high temperatures to terrestrial species and habitats from pests, pathogens, and invasive species. Less frost and warmer damp conditions will increase the prevalence of pests, pathogens, and invasive species.

N10 – Risks from sea level rise to aquifers from sea level rise, saltwater intrusion. Impacts to aquifers are possible due to hydrological connectivity.

N 17 – Risks from sea level rise to coastal species and habitats due to coastal flooding, erosion, and climate factors. Sea level rise can diminish coastal habitats through ‘coastal squeeze’.

The following risks to infrastructure are identified as high currently and high in the future:

I1 – Risks from several sources to infrastructure networks (water, energy, transport, ICT) from cascading failures. Vulnerabilities on one infrastructure network can cause problems on others, and energy infrastructure represents a significant part of this system.

I2 – Risks from surface water flooding and groundwater flooding to infrastructure services from surface water and groundwater flooding – 23% of strategic roads within the city are currently at a 1 in 100 year current risk from surface water flooding which will increase due to increased occurrence and severity of weather events. See figure below that shows current surface water flood risks.

Current risks of surface water flooding and the road and rail infrastructure.

 

Figure 6: Current risks of surface water flooding and the road and rail infrastructure.

Source: Arup and BHCC

I3 – Risks from coastal erosion to infrastructure services from coastal flooding and erosion. While the policy is to ‘hold the line’, funding is not guaranteed and erosion rates at the top of the defended cliff at Brighton Marina are 2.6cm/year. A259 potentially at risk.

I12 – Risks to transport from high and low temperatures, high winds, lightning eg railway lines buckling. Urban heat island (UHI) modelling results show the ‘hot spots’ in the city most vulnerable to road/pavement deterioration, including Hanover, Lansdowne Place, and the area to the south-west of Brighton Station towards Dyke Road. These areas are particularly vulnerable due to the high impervious surface cover and albedo.

The following risks to infrastructure are identified as significant currently and high in the future:

I5 – Risks from extreme weather events to transport networks from slope and embankment failure

I8 – Risks to public water supplies from reduced water availability. Increased periods of drought could impact availability of water supplies to households. Impacts are expected to be less pronounced than other regions of the UK due to the use of groundwater sources that are less vulnerable to short-term summer deficits in rainfall, compared with regions reliant on surface water sources. However, future increased development and population growth puts pressure on infrastructure, including water availability, which could make the risk more significant.

I10 – Risks to energy from high and low temperatures, high winds, lightning &

I13 – Risks to digital from high and low temperatures, high winds, lightning. Summer operation of some facilities is already being affected and this will be exacerbated by projected increases in summer temperatures. Energy and digital assets near the urban city centre of Brighton are most at-risk during summer months, due to the urban heat island effect and through demands for cooling putting pressure on energy networks, causing energy failures.

The following risks to health, communities and the built environment are identified as high currently and high in the future:

H1 – Risks to health and wellbeing from high temperatures – there were an estimated 2500 excess deaths in England in the heatwave of 2020 and a ‘2018-type’ summer will increase in chances by around 50% by the 2050s. Some of this will be exacerbated by the urban heat island effect which will affect densely built up parts of Brighton and Hove (eg Hanover, Lansdowne) more than others and potentially where medical facilities are (e.g. the RSCH) – see figure below.

 

Risk to education and medical facilities from high summer temperatures

Source: Arup and BHCC

H3 – Risks from surface water flooding to people, communities, and buildings; particularly on the A23 and A270 corridors and in the valley bottoms e.g. Whitehawk, Bevendean. The overlap with deprivation is shown in the Figure below.

 

Intersection of health and disability vulnerability and surface water flood risk.

Source: Arup and BHCC 

H11 – Risks from surface water and groundwater flooding to cultural heritage e.g. 29% of 17 key cultural sites are at current risk of surface water flooding, rising to 41% in future and 71% are at moderate risk of groundwater flooding at present.

The following risks to health, communities and the built environment are identified as significant currently and high in the future:

H5 Risks from high temperatures to building fabric - buildings constructed during the 1960s and 1970s used more lightweight methods that have been found to be at greater risk of overheating. However, well-insulated more modern buildings that improve winter energy efficiency can also be challenging to keep cool. Buildings in the city’s ‘hot spots’ are particularly vulnerable.

H12 – Risks from high temperatures to health and social care delivery – up to 90% of hospital wards could be at risk from overheating due to their design. The high density of equipment which produces a lot of waste heat energy make hospitals a particularly hot building typology. Those constructed in the 1960s and 1970s are at particular risk. Positively, the map in Figure 15 shows that medical facilities in the city broadly avoid the hottest areas of the city, as identified from UHI modelling. The demographics of many hospital residents are particularly vulnerable to overheating

H7 – Risks to health and wellbeing from changes in air quality – particularly in areas suffering poor air quality now and areas with a large proportion of population with health deprivation and disabilities eg in central Brighton, the area around Moulsecoomb, especially North Moulsecoomb, but also the area around Pavilion Retail Park, Whitehawk, Woodingdean, and west around Portslade Village and Southern Cross.

H13 – Risks from high temperatures to education – educational facilities in the city are broadly located outside the very hottest parts of the city, however some schools are in relatively hot areas, such as Elm Grove Primary School and Bellerbys College.

The following risks to business and industry are identified as high currently and high in the future:

B1 - Risks to businesses from flooding. Various business parks, Brighton city centre and parts of Patcham are at high risk of surface water and/or groundwater flooding.

The following risks to business and industry are identified as significant currently and high in the future.

B5 - Risks from high temperatures and extreme weather events to business from reduced employee productivity due to infrastructure disruption and higher temperatures in working environments. These will vary across sectors and locations in the city but could be major for example on summer tourism.

B2 - Risks from extreme weather events and coastal flooding to businesses and infrastructure from coastal change from erosion, flooding, and extreme weather events. This could particularly affect Shoreham Port.

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