Contents Page

Summary of Environmental Effects

Ecology and Nature Conservation


Chapter 9: Ecology and Nature Conservation of the PEIR identifies and assesses the potential effects of the Project on the ecology and nature conservation interest of the Project site and surrounding receptors.

Assessment Methodology

Information on ecology and nature conservation was collected through a data gathering exercise to obtain information relating to statutory and non-statutory nature conservation sites, priority habitats and species, and legally protected and controlled species.

Records of protected or otherwise notable species have been requested from the local records centres within a 2 km radius of the Project site boundary, except for bats and otter where a larger 10 km radius has been used in accordance with relevant guidance.

A number of site-specific surveys were also undertaken to assess the Project site conditions. The following surveys were conducted:

Current Baseline Environment

There are 17 statutory designated sites located within the search area. These include three internationally designated sites which are situated within 20 km and 14 nationally designated sites within 5 km of the Project site boundary (see Figure below).

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Statutory Designated Sites

There are no statutory designated sites within the Project site boundary with the nearest being Willoughby Fields Local Nature Reserve, which is located approximately 786 metres to the south of the Project site.

A total of 21 non-statutory designated sites were identified within 5 km of the Project site boundary through the desk study.

The Project site was found to largely comprise low value habitats associated with the airport and infrastructure, comprising large areas of hardstanding and amenity grassland with areas of ornamental shrub and tree planting. These areas are predominantly located within the centre of the Project site. Areas around the periphery of the airport were identified as more natural and included areas of broadleaved woodland and neutral grasslands.

In terms of species, the baseline study and surveys identified 61 species of wintering bird and 72 species of breeding bird within the survey boundary, 48 of which were confirmed to be breeding and three potentially breeding. Grass snakes were recorded within the Project site in two distinct areas, along the River Mole corridor and within the land east of the London to Brighton railway. Great crested newts, smooth newts, common toad and common frogs were also recorded in ponds across the Project site.

The desk study search provided records for at least 14 bat species within and immediately adjacent to the Project site and at least six bat species were recorded across the survey area, including rare species. Two buildings within the Project site were identified as having suitable features present to support roosting bats. However, no bats were recorded emerging from either building, and bat activity was generally very low during the emergence surveys.

Signs of badger activity were recorded during badger surveys. Due to the sensitive nature of badger data, the full findings of the surveys are reported in a confidential report, which is available upon request to those with a legitimate need for the information.

No signs of dormice, otters or water voles were recorded within the Project site boundary.

An invertebrate habitat appraisal identified features of moderate invertebrate interest within the land south of the Aviation Museum and west of the Fire Training Ground, Museum Field and Pentagon Field. The River Mole and Gatwick Stream also supported macroinvertebrate communities and both watercourses had consistently high fish populations.

Mitigation Measures

A number of measures have been designed into the Project to reduce the potential for impacts on ecology and nature conservation. These measures include:

Potential Significant Effects

An assessment of the effects found that the Project would have no effect on statutory or non-statutory designated sites or areas of ancient woodland. The effects on habitats and species are generally found to be not significant. The potentially significant effects are described below.

In terms of effects on habitats, the initial construction phase of the Project (2024-2029) and the following period (2030-2032) would require the removal of species-poor hedgerow and loss of plantation woodland and scrub habitat. The loss of these habitats would result in moderate adverse and significant effects that would not be mitigated for until the end of the construction phase. Additional hedgerow planting would be undertaken early in the construction phase on other parts of the Project site, which would enhance habitat connectivity in these areas. This would result in a moderate beneficial and significant effect in the longer term. 

The Project would require the removal of habitats in the initial construction phase which would result in the temporary displacement of breeding birds. The loss of suitable breeding sites would result in a moderate adverse and significant effect during the initial construction phase (2024-2029). The habitat loss would also result in a temporary moderate adverse effect on the bat and invertebrate assemblages.  This would be a temporary effect until new tree, grassland and shrub planting had established.

No permanent significant effects would arise as a result of the Project.  Some negligible to minor beneficial permanent effects would arise as a result of habitat creation.  

Based on the information available regarding other proposed developments at this stage, no potential for significant cumulative effects has been identified.

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