London - NBS for a leading sustainable city


Regions:
Scale:
Ecosystems:
Grassland, Rivers and lakes, Urban, Woodland and forest
Goals:
Nbs actions:
Topics (Keywords):
Start/End date
Client
Design Team
Awards
Area Characterisation
Objectives

The Greater London Authority (GLA) participants in the BRIDGE FP7  project identified the primary planning goals for the Central Activities Zone (CAZ)[1] as to: (a) increase green space; (b) improve air quality; (c) reduce the UHI effect (heat island) and (d) prevent flash floods, with climate change adaptation and mitigation seen as a cross cutting issue.

London has a number of plans aimed at addressing these challenges, including:

  • The Mayor’s London Plan in which two goals relate to urban green space and aim at addressing vegetation loss, overheating and flooding. To address the former it was envisioned to plant 2 million trees and to increase green space by 5 % by 2030 and another 5 % by 2050 (2011a), with the street tree programme especially targeting areas known to experience overheating. It also has a Living Roofs and Walls scheme focused on creating green roofs and recreational living roofs and green walls to help London adapt to the risks of climate change such as flooding, overheating, drought; and reducing the urban heat island effect in the city (GLA, 2008). The London Plan also has some measurable objectives, including a no net loss of designated Sites of Importance for Nature Conservation over the plan period, a reduction in CO2 emissions to 23 % below 1990 levels by 2016, no net loss of functional flood plain and the production of 945 GWh of energy from renewable sources by 2010 including at least six large wind turbines.
  • The London Infrastructure Plan 2050 sees green infrastructure (GI) as important in its own right and seeks to develop a business case for it (Mayor of London, 2015). The GLA has set up a Green Infrastructure Task Force to work on a more strategic and long-term approach to investing in and delivering green infrastructure.
  • The Mayor’s plan for an All London Green Grid (ALGG) sought to achieve a network of high quality, well-designed and multifunctional green and open spaces and to promote a shift from grey to green infrastructure to secure environmental, social and economic benefits (GLA, 2012). Such a grid was seen as the way to address the environmental challenges of the 21st century — most notably climate change.
  • The Natural Capital Investing in a Green infrastructure for Future London (GLA, 2015) takes forward ideas for the ALGG. It has the vision that by 2050 existing parks and green spaces will become part of an integrated GI network, all regeneration areas and major new developments will include GI (e.g. green roofs and walls) that is designed, amongst other things, for climate mitigation, water regulation and health; streets will be greener and more of London’s rivers will run in more natural courses in order to manage flooding, improve water quality and enhance river ecology. It also wants all people living in London to have ready access to good quality GI and for GI decisions to be based on natural capital valuation.
  • The Mayor’s Air Quality Strategy (GLA, 2010) aimed to minimise greenhouse emissions and the health effects of air pollution through increasing energy efficiency and including air quality impacts in the planning process. It aimed to encourage the development of green roofs and living walls on major new developments, recognising their benefits (and that of GI as a whole) in reducing pollutants, as well as improving energy consumption, the physical environment and helping control runoff.
  • The Mayor’s Climate Change Adaptation Strategy (GLA, 2011b) identified health, environment, economy and infrastructure as key focus areas. It recognised the importance of green spaces in providing ecosystem services, such as reducing flood risk by absorbing and temporarily retaining rainfall and moderating the temperature by offsetting the urban heat island effects, as well as reducing energy demand and supporting biodiversity and recreation. It also set out a vision for a Green Grid across London. The GLA also emphasised the importance of climate adaptation measures and included the suggestion of new trees for shade and green roofs for electricity substations.
  • The Mayor’s Water Strategy (GLA, 2011c) outlines how London can ensure water security and tackle water scarcity and sees GI as contributing to resilience to flooding and extreme weather events, as well as improving air quality. It includes a vision to develop at least three demonstration projects to show how urban greening measures can help to manage surface water flood risk.

[1] The CAZ covers the central London area, including the central business area and the commercial centre, with an overall area of roughly 3 300 ha and about 280 000 residents (BRIDGE Community of Practice Report 2).

Actions

A very large number of NBS projects have been undertaken in London and the potential for different NBS have been assessed by the GLA, including green walls and roofs (GLA, 2008). The examples below are all taken from EU funded projects.

The TURAS (FP7 project) work on green roofs compared the performance of different green roof systems in terms of a number of ecosystem services, including habitat provision/maintenance, water attenuation and thermal insulation. This was to explore the possibility of moving away from an industrial standard sedum system to a more biodiverse green roof system comprising wildflowers and of value to regional biodiversity of national conservation importance (Connop et al., 2013; Connop and Nash, 2014). Ephemeral wetland green roofs were created as a TURAS ecomimicry experiment at the Barking Riverside development, London, UK (Plate 1). The roofs were created to investigate the potential for recreating key habitats associated with the site’s pre-development brownfield state as part of the green infrastructure strategy. Habitat mosaics were created on the green roofs by manipulating the drainage, using different aggregates, and varying the substrate depths. Roofs were then monitored by TURAS researchers to assess how the habitat niches influenced overall biodiversity on the roofs.

In 1968 the River Quaggy in Lewisham, south London, flooded the centre of Lewisham to a depth in excess of 1 metre. There has also been flooding more recently. The aim of the project was to put in place flood control and flood risk mitigation measures, while ensuring no loss of urban green areas (NWRM, no date). Previous flood alleviation measures had consisted of concrete channels and walls and the plan was to raise these further. This would have led to the loss of a large number of well-established trees. Strong local resistance to this resulted in setback flood defences being designed into the gardens of the properties, supplemented by increasing the floodplain in Sutcliffe Park and the storage capacity of the detention basin.

Barking Riverside is a 443 acre brownfield site in the Borough of Barking and Dagenham where development over a 20 year period was designed to deliver 10 800 new housing units for 20 000 residents. The planning process also recognised the ecosystem service potential of the site, such that planning consent set out a number of conditions to ensure the development’s sustainability. These included: the conservation of the site’s valuable biodiversity; the retention of 40 % of the site as green space; and the development of a comprehensive Sustainable Urban Drainage (SUD) system (Connop and Nash, 2014). In the context of the restoration and large-scale sustainable development of the brownfield site at Barking Riverside, TURAS explored multidisciplinary approaches to landscape design that could enhance the environmental, social and economic value of the green infrastructure (e.g. green walls and roofs, SUDs). A key aim was to ensure that the biodiversity and ecosystem service values of the pre-development state of the brownfield site would be conserved throughout the development process and that resilience would be embedded at the heart of the new community (Connop et al., 2016). To do this it used ecomimicry (that is the mimicking of the characteristics of ecosystems) to incorporate habitat interest features typical of regional habitat of national or international conservation value. A community wildlife garden was designed, based on ecomimicry design principles developed by TURAS researchers (Plate 2). Conservation priority invertebrate species and key habitat features associated with the brownfield site prior to the development of Barking Riverside were identified and fed into the design of the garden. The garden was then used to introduce residents to the wildlife that was associated with the site prior to development and residents were shown how they could recreate these features in their own gardens.

The Queen Elizabeth Olympic Park action concerned the assessment (based on one year of monitoring) of the biodiversity value of an existing 0.25 hectare biodiverse green roof to which solar panels had been added (Plate 3). The green roof was designed using ecomimicry principles inspired by the brownfield sites that were in the area prior to the Olympic Park development. The photovoltaic panels were arranged to enhance the habitat mosaic and TURAS researchers worked to monitor the roof development to assess whether an effect of the design could be quantified in terms of niche provision for biodiversity. It was found to have high invertebrate diversity compared to other green roofs in London. Some important local and national species were recorded (Nash et al., 2016). Other facets of the roof also contributed to the richness, such as habitat piles and different substrates. Some concern has been expressed about the possible need for the irrigation of green roofs, especially in their early stages and the potential for conflict under water scarcity (BRIDGE Task 3.1), although there is no agreement on whether this is an issue.

The Beetle Bump (Plate 4) — a brownfield-inspired nature reserve constructed and monitored at the University of East London (UEL), Docklands Campus, London as part of the TURAS programme. The project was a rescue attempt for what was probably Britain’s rarest insect, the streaked bombardier beetle (Brachinus sclopeta). The beetles were found on a nearby brownfield site that received planning permission for development (UEL, 2014; TURAS D2. 3). The beetles were rescued by UEL and Buglife staff and the ‘Beetle Bump’ was created using ecomimicry design principles. Made from 65 tonnes of recycled materials (hard core, chalk, brick and topsoil) and seeded with floral species typical of the high quality open mosaic habitat typical of the region’s best brownfield sites, the Beetle Bump was designed as a multifunctional space blending art, landscape design and conservation of habitat to support the streaked bombardier (Connop, 2012). Beetles rescued from the donor site were released at UEL where the site was used as an open-air laboratory to study the behaviour and habitat requirements of the beetles and the benefits of urban brownfield landscaping. 

Potential impacts/benefitis

NBS benefits
Transferability of the Results

Lessons learned

  1. Cost-effectiveness

The GLA have estimated that an average of 32 % of roof area could potentially be greened (GLA, 2008) and two options have been explored (GLA, 2008). The first is to install green roofs covering an area of 226 750 m2 in four inner city areas, which would cost around GBP 4 million (EUR 4.5 million, exchange rate 7 November 2017) and provide environmental benefits worth GBP 4 million (EUR 4.5 million, exchange rate 7 November 2017). The second option would comprise a much larger area with 3.2 million m2 of roof space and would cost around GBP 55.5 million (EUR 63 million, exchange rate 7 November 2017), but with additional environmental benefits. A 850 m2 retrofitted green roof on a building in Canary Wharf, has achieved an estimated reduction of 25 920 kWh [11.46 CO2 eq. tonnes] a year through reducing heating and cooling of the spaces below the roof, with an estimated saving of up to GBP 4 000-5 000 per year in electricity [pers.comm. Tony Partington Canary Wharf Co. in GLA, 2008].

The River Quaggy project found that the NWRM costs were generally lower than those for more ‘traditional’ measures, and while the costs associated with re-meandering the channel and creating the detention basin were not small, a greater range of (multiple) benefits was achieved (NWRM, no date).

  1. Lessons learned

The River Quaggy project identified a number of key lessons including the importance of early and continued consultation during all phases of the project to develop project ownership by the community (NWRM, no date). This helped in the implementation and operation of the setback flood defences in a highly residential area, by the use of private gardens. The project employed a full-time public liaison officer during the planning and implementation phases. Communication and a positive attitude are essential. A catchment-scale approach allowed for greater overall improvement by enabling some measures that could not have been implemented in isolation.

Lessons from the TURAS work in London include: getting NBS implemented takes longer than expected, so allow for this; while one can control a small-scale experiment one cannot control things in practice when dealing with nature, so one has to be flexible; there is a need to embed monitoring progress in the design phase as it is very hard to retrofit it and that legacy management needs to be planned at an early stage (Connop, pers. comm).

Publications & Reports
Financing

The Land Trust has developed a service charge financial model for developers to ensure green space is well-maintained in the long term. This model involves residents within all new houses contributing to the annual costs of maintaining the green spaces, with the funding also covering some of the costs of a community ranger who generates community involvement, volunteering opportunities and organised events and activities. This is seen as having the additional benefits of improving the health and well-being of the residents, while providing educational opportunities and involving them in habitat maintenance.

The monitoring of the Olympic Park biosolar roof was made possible by the support of the London Legacy Development Corporation, one of whose aims is to secure a biodiversity legacy for the London 2012 Olympic Games (Nash et al., 2016).

In London there are sources of money which can contribute to further work or co-finance projects e.g. Drain London, Thames Water, Regional Pocket Parks.

Organisations
Contacts

Peter Massini, Principal Policy & Programme Officer, Green Infrastructure Development, Greater London Authority

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