Green Infrastructure Strategy
- Executive Summary
- Our Approach
- Setting the Scene
- Flood Regulation
- Temperature Regulation
- Air Quality Management
- Health and Wellbeing
- Social Cohesion
- What do our residents say?
- Delivering our strategy
- How will we measure success?
Vision: “to create an interconnected, healthier city that reliably delivers ecosystem services for its residents and wildlife”
- In this strategy, the term Green Infrastructure (GI) covers both green and blue infrastructure. GI is a network of natural and semi-natural areas capable of providing a suite of environmental benefits. GI which is linked together in urban settings creates a network, a Green Grid, which is able to provide multiple benefits including supporting a green economy, improving quality of life, protecting biodiversity and enhancing the ability of ecosystems to deliver benefits (Ecosystem Services) such as improving water and air quality, providing space for recreation/relaxation and climate change mitigation and adaptation.
- In Southampton, GI includes open spaces (such as parks and gardens), greenways, allotments, woodlands, grassland, road verges, hedges, ditches, rivers, streams, lakes, ponds, playing fields and coastal habitats, as well as footpaths, cycleways and railway corridors.
- Southampton has long been known as a green city. With its diversity of parks, semi-natural spaces and two chalk rivers (the Test and the Itchen) flowing through it into the Solent; we have a wealth of GI for such an urban setting however, much of our GI is fragmented.
- As in the vast majority of towns and cities, benefits from GI are not well understood, let alone properly valued. This situation risks the loss of critical natural capital at a point in time when we need it most. With a backdrop of rapidly diminishing budgets, green and blue infrastructure that can provide a diverse range of benefits, simultaneously, is a vital resource.
- This strategy is, quite naturally, incomplete; no matter how long we spend gathering information we can never know all there is to know about the natural environment. However, this is no reason to delay taking action.
“We may have distanced ourselves from nature, but we rely completely on the services it delivers.”
Living Beyond Our Means: Natural Assets and Human Well-being. The Board of the Millennium Ecosystem Assessment (2005).
This simple statement neatly sums up our current relationship with the natural world. However, as the information in this strategy illustrates, this is a dangerous road to travel risking a loss of human wellbeing and prosperity.
The worst consequences are not inevitable; by adopting a new approach to the natural environment we can better understand the benefits we are receiving and ensure that safeguarding them is integrated into the council’s policies and practices. In this way, we can restore the health and wellbeing of our communities and achieve long term sustainable prosperity.
- Following local and national activity, Southampton City Council declared a climate emergency in 2019 and published its Green City Charter, identifying key priorities to create a cleaner, greener, healthier and more sustainable city. Since then, we have gone on to demonstrate how we intend to deliver on this Charter through the Green City Plan. As part of our commitments, we are developing a robust, bigger, better, well linked network of GI; a Southampton Green Grid. This will help us recognise, record and safeguard existing GI in Southampton. It will identify how the optimum benefits can be achieved by introducing more, well designed GI to deliver much needed Ecosystem Services across our city. This well designed, well connected, robust Green Grid, will provide benefits for both the city’s wildlife (much of which has decreased and/or deteriorated) and our increasing population. An increase in more, better linked GI will be imperative in helping the city meet its net zero carbon goal by 2035 and be part of the solution to tackling climate change.
- Developing our Green Grid started in January 2021. The first step involved the production of a series of maps by Geodata (Southampton University), clearly identifying all of our existing green and blue spaces. This was followed by analysis of socio-economic data alongside other data sets, including priority habitats, designated sites, street trees and public rights of way. As part of the development of our Green Grid, we are identifying opportunities to utilise buildings and land to add to the Green Grid through the creation of green walls/facades and green roofs, tree planting and wildflower areas. We will also be working with landowners across the city, assessing opportunities for forming links in the Green Grid on non-council land, encouraging the implementation of GI wherever we possibly can to create a resilient, healthy, climate change resilient city.
- Policies and Supplementary Planning Documents within the Local Plan are being reviewed and will include clear guidance on the GI standards we expect as part of any development. Our Green Grid map will show where this GI is most needed and we will provide guidance on the type of GI we expect to be delivered, ensuring it is good quality and suitable for our city setting. We will ensure our cityscape is well designed and high quality, ensuring the built environment meets the highest of standards in all cases and is resilient to challenges such as climate change and increasing population.
- This is a city-wide strategy and once adopted, a more detailed plan will be developed to explain how we will implement the strategy. Our GI Delivery Plan will include how GI will be delivered (ie. reduced mowing of our grassland areas to increase sward height, more hedgerows and trees, roadside planters), where and when this will be delivered and by whom. To create well-connected and well-designed GI will require input and energy from communities and landowners across the city. We can achieve a greener, better linked and healthier city if we all work together.
- We will find ways to quantify the Ecosystem Services delivered by good quality, well planned GI so investment can be based on sound business cases and to find innovative ways to use this to attract investment through insetting (a mechanism to help businesses tackle effects of climate change and biodiversity loss) and social value schemes.
We have identified seven priorities:
- Biodiversity. We want to develop a city that supports a diverse range of species, with robust population levels and a connected network of habitats that is accessible to both people and wildlife.
- Flood Regulation. We want a network of GI that reduces the risk of flooding across the city and has sufficient capacity to cope with all but the most extreme weather events.
- Temperature Regulation. We want to ensure there is sufficient GI within Southampton to moderate the effects of high temperatures and poor air quality caused by the Urban Heat Island and climate change.
- Air Quality Management. We want extensive, well-connected GI that helps improve the city’s air quality and reduces pollutant levels to below national thresholds.
- Health and Wellbeing. We want sufficient GI across the city which provides opportunities for residents to get outside and enjoy access to nature and we want more tranquil places for people to relax and unwind.
- Recreation. We want residents to have access to a variety of GI, close to their homes, which provides opportunities for a range of recreational activities.
- Social Cohesion. Green spaces are at the heart of community activity, we want to provide more opportunities for friendship and collective action.
A further three potential priorities have been identified and will be developed further as supporting evidence is gathered. These are:
- Economic Value – a high quality green and blue environment in which to live and work that supports the prosperity of the city.
- Education and Skills Training – green spaces are a focal point for education and training, providing skills for employment and skills for life.
- Carbon Capture – Improving our GI is integral to helping the council achieve our net zero targets (our Climate Change Strategy and Climate Change Delivery Plan provide further details).
Setting the Scene
- Parks and green and blue spaces in England deliver an estimated £6.6 billion of health, climate change and environmental benefits every year. But with 80% of people now living in towns and cities, one third of people do not have access to good quality green and blue space within 15 minutes of their home (Natural England). In February 2023, Natural England launched their new GI Framework. The new Natural England GI Framework will help increase the amount of green cover in England to 40% in urban residential areas; one of its priorities is to connect people to nature by creating accessible nature-rich spaces close to where people live and work. Improving access to GI for particular groups of people would contribute to reducing inequalities such as mental and physical health in different areas of the city.
- The council will adopt this GI Framework and use it to help improve and increase the green and blue spaces across the city, playing its part in helping to halt the loss of habitat. We realise the importance of acting without delay; halting the decline and fragmentation of GI in the city needs to be addressed urgently. Making important changes now to how we deal with our natural environment will have lasting physical and mental health benefits for the city’s population and make the city a more attractive place to live in, work in, and visit. This strategy, along with our other strategies (including Climate Change and Biodiversity Strategies and our Public Realm Masterplan), outline the key ways in which we will work together with our partners to make improvements in the quality and extent of green and blue space across the city.
- One of the requirements of the Environment Act 2021, is the development of spatial strategies for nature, a National Nature Recovery Strategy. At the local level, Hampshire County Council (HCC) is producing a Local Nature Recovery Strategy (LNRS). This GI Strategy, along with the Green Grid mapping and GI Delivery Plan, complements the LNRS work of HCC, by providing more detail and guidance at a scale that is relevant to the city.
- The city has a large amount of green space. It has 49 parks and 1,140 hectares of opens spaces, including the Common which hosts over 17 million visitors each year. In total, 20% of the city is classified as green space. It neighbours the New Forest National Park, Southampton Water, the Solent and the range of protected habitats within them. The city supports a wide variety of habitats including coasts, mudflats, rivers, ponds, wet meadows and woodlands. Some of these habitats are of national and international importance, including our two chalk river systems.
- The main current drivers of GI loss in Southampton include climate change, pressure from increased development, absence of, or poorly designed, GI as part of development, pollution (both on the land and in our watercourses), increasing public pressure and lack of/inappropriate management of habitats. Over time, the green areas of our city have become more and more fragmented, and our rivers and streams have become polluted and unnatural. Small-scale, incremental encroachment on incidental spaces (including road verge loss and reduction of private gardens) is eroding the green network for both people and wildlife
- The term ‘biodiversity’ is a shortened version of ‘biological diversity’ which can be defined, very simply, as the variety of life.
- Biodiversity forms the fabric of GI. This ranges from very common to extremely rare species. The strategy addresses the two different facets of biodiversity and its interaction with GI. Firstly, as the basis of GI there is a need to ensure the resilience of the species that are providing the Ecosystem Service benefits that we want delivered. Secondly, there is the issue of biodiversity conservation where we take specific actions to reverse the losses of species and improve the size and resilience of populations. This second aspect is covered in detail in the Biodiversity Strategy
- Biodiversity has long been appreciated for the goods and services it provides and the way it enhances our quality of life. However, this has not prevented significant losses occurring. Significant declines have been caused by human activities such as agriculture, urban development and pollution. Within Southampton, for example, intensification of the built environment through building on gardens, open spaces and over watercourses has led to further losses.
- Biodiversity plays a key functional role in ecosystems and hence the delivery of Ecosystem Services. Whilst the precise role it plays is not well understood, it appears that ecosystems are more stable with higher levels of biodiversity which means that maintenance of good levels of biodiversity is key to ensuring future provision of Ecosystem Services.
- Unfortunately, despite concerted efforts at both the national and local level, biodiversity is still in decline which could result in a reduction, or loss, of Ecosystem Services. The consequences of this decline would be particularly noticeable in urban areas such as Southampton where large numbers of people, who benefit directly from Ecosystem Services, live.
|What do we want to achieve?
|How will we achieve this?
|GI which contains the right species and is made up of habitat types which are capable of coping with environmental challenges, such as climate change and population increase. Offset some of our current carbon emissions through localised habitat creation.
|Ecosystems within the city are in good condition and Ecosystem Service provision is protected. Good quality GI which supports the delivery of the Local Nature Recovery Strategy. Better access to greenspace whilst at the same time, improving habitat quality.
- Flooding is one of the most significant challenges faced by Southampton. It poses a risk to the health and well-being of residents (ie. drowning and infections caused by contaminated water); it damages homes and infrastructure, and interrupts businesses, causing losses to the local economy.
- The risk to the city is increasing. A rise in the frequency and severity of extreme weather events, linked to climate change, will result in more rainfall. Unfortunately, the fabric of the city, in common with most urban areas, is very poor at dealing with water. Extensive areas of impermeable surfaces on buildings, roads and pavements speeds water into the nearest drain leading to water, and in some cases sewage, overflowing onto roads and into property.
- Some areas of the city will fare better than others. Those areas with higher levels of GI and less “sealed” surfaces, will benefit from the greater levels of water interception and infiltration provided by vegetation and soils. Features such as woodlands, wetlands, meadows and gardens all have an important role to play.
- Areas with little or no GI, for example the city centre, will be more at risk. However, the inclusion of green roofs, green walls/facades, SuDS and street trees in new developments, or retrofitted into existing areas, can help.
- The focus going forward will need to be on the protection and management of existing GI, including gardens, and the creation of new features to increase water storage capacity.
|What do we want to achieve?
|How will we achieve this?
|A city-wide network of green infrastructure capable of delivering high levels of water interception and infiltration will have been identified. New developments will include GI leading to an increase in water storage capacity. Green roofs, green walls/facades and SuDS will have been retrofitted into city centre sites.
|Southampton will develop a network of green and blue infrastructure that reduces the risk of flooding across the city and has sufficient capacity to cope with all but the most extreme weather events.
- Urban areas are generally warmer, often by a degree or two, than surrounding countryside due to the release of heat from buildings and man-made surfaces. This is termed the Urban Heat Island effect.
- The main causes of the Urban Heat Island effect are the release of heat from buildings and other man made surfaces into the atmosphere at night which causes an increase in urban air temperature; and the loss of evaporative cooling from vegetation which has been replaced by built structures.
- Solar radiation is the principal source of heat being released from buildings and other surfaces. However, this is often supplemented by waste heat from air conditioning and the effects of vehicles and industry.
- Climate change is increasing the incidence of heat waves and exacerbates the Urban Heat Island effect which has serious implications for health (i.e. increasing risk of heart attacks and respiratory issues) and the economy. Along with warming at the Earth’s surface, many other changes in the climate are occurring including rising sea levels and more extreme weather events.
- GI has been proposed as an effective tool for mitigating the adverse effects. It has been suggested that a 10% increase in tree cover in a dense urban area, would result in a cooling by up to 2.5oC.
- GI reduces temperatures in a number of ways: moisture is released into the atmosphere by evapotranspiration and reduces the ambient air temperature around vegetation, large plants such as trees and shrubs provide direct protection from both heat and UV radiation by shading buildings and outdoor space. Lower temperatures as a result of evapotranspiration and shading lead to a reduction in the amount of heat absorbed by man-made urban surfaces.
- Many areas in Southampton benefit from good levels of GI and will not be at risk from the Urban Heat Island effect. However, the high density of population and lower levels of GI within the city centre increases the risk of Urban Heat Island.
|What do we want to achieve?
|How will we achieve this?
|The severity of the Urban Heat Island effect has been reduced through the creation of new GI. Shade spaces have been created to provide cool spots which enable residents to gain relief from high temperatures. Residents have access to shade spaces which allow them to safely enjoy time outdoors.
|Ensure there is sufficient GI within Southampton to moderate the impacts of high temperatures and poor air quality caused by the Urban Heat Island effect.
Air Quality Management
- Poor air quality is the greatest environmental risk to health, including increased risk of cancer and other chronic diseases. The key pollutants are Nitrogen Dioxide (NO2) and Particulate Matter (PM).
- NO2 is mostly from road transport, although other sources, including industry and shipping, do contribute towards high levels. The city has ten Air Quality Management Areas where statutory air quality objectives haven’t been met.
- PM comes from a large variety of sources, notably wood burning, and can have large impacts on health.
- Pollution can also have an impact on vulnerable habitats, making them less resilient to other stressors.
- While air quality has improved in the city since monitoring began, pollution still has a large impact on the city’s residents, particularly those in vulnerable demographics. In response to this, the council has adopted its new Air Quality Action Plan which aims to achieve a continual improvement in the city’s air quality. The Air Quality Action Plan sets out a series of measures to reduce emissions overall and reduce the impact of pollution through minimising exposure to pollution.
- As well as absorbing some pollution, GI, including hedges and green walls/facades (with the right choice of species), can help mitigate the impact of pollution by creating barriers between the source of pollution and people.
- It is important that green infrastructure is planned well to ensure unintended increases in pollution do not occur. Planting of certain tree species can, in some cases, limit the dispersal of pollution and worsen air quality in an area.
|What do we want to achieve?
|How will we achieve this?
|Improved air quality within Air Quality Management Areas. Improved background air quality.
|Effective use of GI is improving the city’s air quality and reducing pollutant levels to below national thresholds.
Health and Wellbeing
- Ecosystems provide some obvious benefits for health including proving fresh food, clean water and clean air. They also provide places for people to be active and to have contact with nature contributing to improved physical and mental wellbeing. Beyond this, ecosystems regulate environmental processes such as water management, temperature regulation and air quality which, if disrupted by environmental degradation, can become harmful to health.
- The idea of parks and green space being good for health can be traced back to Victorian times. Many of the parks in Southampton were established under the Public Health Acts of 1875 – 1925. Research has since shown that access to green space benefits both physical and mental wellbeing. Parks are particularly important in urban areas where populations tend to have higher levels of physical and mental ill health than their rural counterparts. Parks provide opportunities for physical exercise, which would combat the problem of growing inactivity and associated medical conditions such obesity, Type 2 Diabetes and Cardio-Vascular Disease however, they need to be located close to where people live.
- Not everyone is able to take vigorous exercise, however, gentle exercise can still provide benefits. The critical factor is contact with the green environment.
- Access to the natural environment also has indirect benefits through greater social contact. It is particularly important for children enabling them to develop self-confidence and important social skills. It helps reduce stress and negative emotions and increases happiness. GI also helps boost attention, memory and creativity and mitigates noise pollution which in turn reduces stress and sleep disturbance.
- In general, deprived areas have less green space and where it exists, it is generally of poorer quality than that in more affluent areas. This is a significant health issue as deprived communities tend to experience higher levels of ill health and, whilst the health of all members of society benefits from improved access to greenspace, the health of individuals in the lowest socio-economic groups benefits the most.
|What do we want to achieve?
|How will we achieve this?
|The general health and wellbeing of the city’s residents has improved as people spend more time out and about in parks and green places.
A range of different GI is meeting the needs of residents; whether they want to engage in vigorous exercise or to simply sit and unwind.
|More connected GI across the city, more access to our waterfront, providing greater opportunities for residents get outside and take more exercise and unwind. We will have tranquil, safe, high quality, accessible places for all to spend time in.
- Physical inactivity is a growing problem which is thought to be at the route of many common health problems including obesity and heart disease and is a major concern for general health and wellbeing. There is a growing need to reverse the trend of increasing inactivity in order to improve the health of residents and reduce costs for the National Health Service
- GI provides a diverse range of opportunities for activity including, walking, cycling and gardening. In addition, recreation within green spaces has been shown to be more beneficial than equivalent exercise indoors as a consequence of the body’s positive response to natural places.
- Not all green spaces will be able to accommodate the full range of activities whilst some activities, for example cycling and play areas for small children, may conflict. The challenge will be to maximise the range of activities that can be provided by each green space without damaging the sites’ features or detracting from the quality of experience.
- Education material and supported activities such as guided walks, cycle routes, green gyms or Park Runs, may be helpful in encouraging more people to become more active.
|What do we want to achieve?
|How will we achieve this?
|There has been an increase is the number, and the diversity, of people taking regular exercise. A range of opportunities for physical exercise within green space is available and meets the needs of all members of society, ‘something for everyone’. Health problems related to inactivity are declining in prevalence.
|Residents have access to a variety of green space, close to their homes, which provides opportunities for a wide range of recreation activities.
- Access to good quality green space can play a significant role in community cohesion which is closely linked to health and quality of life benefits for individuals.
- The presence of green space has been shown to draw people outside which provides opportunities for social interaction and helps to break-down barriers. This can be especially helpful when trying to tackle mental health problems. Improved access to green space can be particularly helpful for groups such as seniors, children, ethnic minorities and Disabled People which tend to experience higher levels of social exclusion.
- The presence of community ‘Friends of’ groups provide people with an opportunity to come together to share a common interest. Events and activities such as guided walks organised by community groups can encourage people to be more active whilst conservation projects result in positive improvements to the local environment and generate a sense of achievement.
- Higher levels of social interaction is thought to be the reason why good quality green space has been found to reduce crime and violence levels.
|What do we want to achieve?
|How will we achieve this?
|There is an increase in the number and range of park centred community activities providing opportunities for all residents to get involved.
There is an increase in residents’ feeling of safety when visiting their local park. There is a reduction in crime levels within communities surrounding parks.
|Sufficient good quality, safe green space which provides opportunities for residents to meet their neighbours and engage in community projects.
What do our residents say?
- Consultation with residents and city users over their thoughts on existing GI in the city (Green Grid consultation, 2022) resulted in one of the most well responded to consultations that the council has ever run, with over 2,500 responses.
- The most important priorities in local areas and the city centre are parks, open spaces, nature and conservation, and better access to the coast/shoreline. Concern about the environment and climate change were cited as the most important challenges faced by the city (City Vision 2020).
- 98% of consultation responses stated people would like more nature and wildlife in the city.
- 84% of respondents said they enhance their outside space for wildlife, the majority of people do this by planting wildlife friendly plants, having a pond and not mowing to encourage insects, hedgehogs and birds.
- The majority of the city’s residents who responded said they are involved in improving the city’s wildlife, with just 18% of respondents not taking any action.
- 89% of respondents feel that using locally native species for planting is important for encouraging wildlife and improving habitats, and that plants and trees used in landscaping, should be chosen to be of benefit to wildlife.
- 91% of respondents say that street tree planting improves the character of an area.
- Nearly half of respondents mentioned the Common as being their favourite green space in the city due to its close proximity to where they live and being able to walk there. Riverside Park was cited as the next most visited green space. St James Park received overwhelming positive comments (85% of respondents said they felt positive about this park). Mayflower Park received the largest number of negative comments.
- 91% of respondents said they would like to see more green spaces in the city and that they would like the green spaces to be better maintained, providing better access but also better facilities (such as seating, toilets, interpretation signs, way markers) and more information to be available to advertise those spaces and how to get to them, especially the smaller ones.
- Asked about what would encourage people to make use of their green space more, the majority of respondents cited more wildlife, peace and tranquillity, biodiversity and better management.
- People feel that as a city near to the sea, access to the waterfront should be improved, particularly on the west side of the city. People said they felt the rivers and coast were almost “ignored”.
- Many people have concerns about safety and lack of any apparent management of green spaces, resulting in them feeling run down, neglected and therefore more prone to vandalism.
Delivering our strategy
GI needs to be provided across the city. However, to ensure it is resilient, it needs to form a network. A network of the key GI in the city has been identified through work with Geodata; this network is called the Green Grid. The Green Grid pulls together delivery of all the priorities listed in this strategy and the Biodiversity Strategy; it comprises our most important GI and biodiversity sites, our key recreational network and our key connections. A set of Ward-level maps will be produced to detail where existing GI is located and where new GI is needed to form the network. These maps, together with a GI Delivery Plan, will provide further detail on delivery of GI in terms of the “how, what, where and when”.
- The aims and objectives of the Local Plan, along with other council strategies, including the Greenspace Strategy, Biodiversity Strategy, Climate Change Strategy and Health and Wellbeing Strategy, will all align. This will ensure that Council efforts are consistent and joined up.
- Irrespective of what portfolio the land falls within, and who is the landowner (ie. education, housing, corporate), we will ensure the Council’s land management practices are consistent, well designed and contribute towards building a network of good quality, linked GI across the city.
- Development design, including green and blue infrastructure, will be guided by the Local Plan and the Green Grid map and will adopt the Public Realm and Green Space Factor toolkits, delivering green and blue areas and providing links. GI delivered by the planning process will align with guidance such as Natural England’s GI Framework Standards and Building with Nature Standards. This would ensure a consistent approach and high standards. BNG delivery will be key in providing the right GI in the right areas.
- Working with neighbouring LPA’s, we will protect and enhance green links between Southampton, Eastleigh, the New Forest and Test Valley
- Partners will include Southampton National Park City, Southampton Common and Parks Protection Society, Southampton Natural History Society, Hampshire and Isle of Wight Wildlife Trust, SO18 Big Local, Pollinating Peartree, Sholing Valley Study Centre Association, Green Volunteer Network, Friends of Groups, Natural England, adjoining Local Planning Authorities, Environment Agency, local communities, schools and the commercial sector.
- We will produce Ward-level maps to show where GI is needed to “fill in the gaps” and a delivery plan detailing how and when that will be achieved. These maps, together with GI Delivery Plan, will be developed in partnership with the community to ensure residents are fully engaged in the process and therefore have a sense of ownership.
- Working collaboratively, we will reduce unnecessary reliance on resources such as water, chemicals or machinery where possible. We will reduce our CO2 emissions (becoming net zero in 2035) and embed a culture of “sustainability” in all council actions across all of our service areas and within our procurement process, including the choice of contractors we employ.
How will we measure success?
The GI Strategy is linked with other strategies which contain information on specific targets and how success will be measured. In addition to those targets, we will also:
- Increase the amount of land designated as Local Nature Reserve (LNR), aiming to meet the Natural England ANGSt target of at least one hectare of LNR per 1,000 people.
- Increase the number of parks with Green Flag status.
- Increase and measure the level GI, such as tree cover, in the city.
- Ensure no net loss in GI and deliver no less than 10% BNG for all relevant development, secured via the planning system, delivered within the city.
- Improve the condition of our semi-natural habitat and aim for “favourable conservation status” for all of our designated sites.
- Increase the amount of land designated as SINC.
- Set clear targets within our updated BAP to monitor the health of biodiversity.
This GI Strategy, together with our closely aligned Biodiversity Strategy and the work to develop the Green Grid, will contribute to an overall improvement in the health of the city. We anticipate that making our city greener, more connected and attractive, and therefore a healthier place to live and work, will also result in economic benefits for Southampton.