Publication Local Plan, Chapter 23: Biodiversity and geodiversity

23.1 The government’s 25 Year Environment Plan [1] recognises that in order to leave the environment in a better condition for the next generation, we need to restore and create wildlife habitats, looking beyond existing designated sites to the wider environment. The national biodiversity strategy [2] recognises that biodiversity is important not just in its own right but because it is critical to human survival. It provides us with services that are vital to our wellbeing and economic prosperity. The UK National Ecosystem Assessment concluded that decision-making consistently undervalues nature, and that many of the services that it provides are in decline [3]. The message at the national level is therefore clear that biodiversity issues need to be taken more seriously and are a key component of sustainable development.

23.2 The Local Plan seeks to respond to this challenge through a comprehensive range of measures aimed at ensuring that Salford’s biodiversity resources are protected and enhanced. The overarching aim is to deliver a significant net gain in the city’s overall biodiversity value, and to enhance the ability of ecological networks to adapt to climate change. All parts of the city and all developments have a role to play in this, and the cumulative benefit of small-scale improvements in biodiversity resources should not be underestimated. Other policies in the plan will support biodiversity improvements, particularly those relating to green infrastructure (chapter 22) and the quality of water bodies (policy WA1).

23.3 There are no nationally or internationally designated sites in Salford at present, but a Site of Special Scientific Interest is proposed at the heronry in Botany Bay Wood. The local designation of Sites of Biological Importance (SBIs) is assessed at the Greater Manchester level, and there are currently 32 such sites in Salford. Many of the SBIs include priority habitats identified in the national and/or local biodiversity action plans, although such habitats are also found in other locations across the city.

23.4 The establishment of a Biodiversity Heartland within Chat Moss offers the most significant opportunity to enhance Salford’s biodiversity resources, with the potential to secure significant areas of lowland raised bog restoration, which is a European priority habitat. This area forms part of a wider ecological network within the Great Manchester Wetlands Nature Improvement Area, which extends into Warrington and Wigan, where it includes the Manchester Mosses Special Area of Conservation. There are numerous opportunities elsewhere in Salford to secure significant biodiversity enhancements, ranging from strategic areas such as the Irwell Valley to individual development sites.

Nature Improvement Areas

23.5 The Great Manchester Wetlands Nature Improvement Area (NIA) was adopted by the Greater Manchester and Cheshire Local Nature Partnerships in May 2013, and currently covers around 48,000 hectares extending across parts of Salford, Wigan and Warrington. The area of the NIA within Salford is shown on the Policies Map and in Figure 19. There is scope for the boundary of the NIA to change in the future, should circumstances change.

23.6 The main focus of the NIA can be broadly split into three different landscapes:

• The Mosslands, defined by the peaty soils and the flat topography associated with the former lowland bogs, which accounts for that part of the NIA within Salford and extends into Wigan and Warrington
• The Mersey Valley Wetlands Corridor, which has the Glaze Brook along the south-western edge of Salford as its eastern boundary and lies within Warrington
• The Flashes in Wigan

23.7 The vision is for the NIA to become an exemplar of biodiversity restoration, enhancement and the delivery of landscape-scale ecological networks. A central part of this is to deliver a coherent collection of wetland habitats that will help to buffer existing designated sites and connect important habitats to allow free movement of key species, which will become increasingly important in mitigating the impacts of climate change. The whole of the Chat Moss area in Policy GI2 falls within the NIA, and the Biodiversity Heartland is one of the priority areas for habitat restoration and creation.

23.8 The NIA designation does not prevent new development. However, a location within the NIA makes it essential that a high level of green infrastructure is incorporated within the development site in order to increase the area of priority habitats, improve connectivity between habitats and species populations, and enable the movement of species within the NIA and beyond, and also for development to contribute to off-site improvements within the Biodiversity Heartland to help deliver the NIA objectives. The provision that is expected will vary depending on the characteristics of the site and its location within the NIA.

23.9 The further designation of Nature Improvement Areas will be supported where appropriate, with the Irwell Valley being a high priority.

Development and biodiversity

23.10 If development is to be genuinely sustainable then it will be vital for it to play a full role in protecting and enhancing Salford’s biodiversity resources. Development generates opportunities to help achieve an overall nature conservation benefit, and it will often be possible to secure significant improvements through relatively simple measures, such as the incorporation of green infrastructure and features including bird/bat boxes and bricks that can enable wildlife to disperse throughout the city. On-site biodiversity improvements will also be vital to enhancing the liveability of urban areas, and improving the connection of people to nature, particularly as development densities increase.

23.11 The ways in which developments secure a net gain in biodiversity value will vary considerably and be relative to the scale and nature of the site. Major developments will need to use the most up to date Defra metric [4] or equivalent in order to assess current biodiversity value and demonstrate a net gain in biodiversity value of at least 10%. Minor developments will assess biodiversity and demonstrate net gain in a manner that is proportionate to the site. On some sites, the focus will be on the retention of existing habitats. For others, this may be impracticable, and it may be necessary instead to make significant provision for new habitats either on- or off-site. It can be challenging to establish new habitats, and this will be taken into account when assessing the appropriateness of proposed mitigation measures. It is essential that the most important and irreplaceable habitats in the city are protected, and so mitigation rather than retention will not be appropriate in some circumstances. It will also be important to ensure that invasive species such as Japanese Knotweed are controlled.

23.12 In the case of the Biodiversity Heartland, it will be important not just to protect the biodiversity resources that already exist, but also to support restoration schemes and secure further enhancements in the area’s nature conservation value where possible. This reflects the overall strategic importance of this area both within Salford and as part of a wider ecological network.

Geodiversity

23.13 Geodiversity refers to the range of rocks, minerals, fossils, soils and landforms in an area. Salford has one site identified as meriting designation for its geological interest, located within Clifton Country Park. Other parts of the River Irwell valley are also of potential geological significance but none have been designated at present. Apart from the Irwell Valley and the extensive peat soils of Chat Moss, features of geological value are scarce within the city. The most well-known asset is the former quarry at Worsley Delph which is also a site of very significant heritage interest. It will be important to provide appropriate protection for such features, both in terms of their inherent geological value and to maintain their contribution to local character and identity. It will also be important to have regard to the requirements of Policy GB2 in respect of the sustainable use of soils.

Monitoring

23.14 The main indicators that will be used to monitor this chapter are:

References

[1] Department for Environment, Food and Rural Affairs (2018) A Green Future: Our 25 Year Plan to Improve the Environment

[2] Department for Environment, Food and Rural Affairs (2011) Biodiversity 2020: A strategy for England’s wildlife and ecosystem services, p.4

[3] UK National Ecosystem Assessment (2011) The UK National Ecosystem Assessment: Synthesis of the Key Findings

[4] Currently Beta Biodiversity Metric 2.0 (published July 2019)

[5] Unpublished work by Salford City Council

[6] Designations under policy BG2 SLP: DMP Policies Map (based on 2017 surveys)

[7] Unpublished work by Salford City Council, incorporating evidence from 2018 Single Data List Indicator 160 return to Defra

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