Tendring Colchester Borders Garden Community Development Plan Document (DPD)

Natural England is a non-departmental public body. Our statutory purpose is to ensure that the natural environment is conserved, enhanced, and managed for the benefit of present and future generations, thereby contributing to sustainable development.

A number of modifications have been made to the DPD since the Regulation 18 consultation and many take into account the representations previously made by Natural England. There are, however, certain issues which require further consideration and clarification. These fall under the general headings of “Green Infrastructure Provision” and “Delivery of mitigation required by Habitats Regulations Assessment/Appropriate Assessment (HRA/AA) in DPD Policy”. Your attention is drawn to our advice on the HRA/AA of the potential effects of the DPD upon air quality at European Sites as this may require a more fundamental review.

Green Infrastructure Provision

Natural England has previously highlighted the need for the Garden Community to deliver sufficient Suitable Alternative Natural Greenspace (SANG) to mitigate the increased recreational pressure that the new housing will give rise to at the European Sites at the Essex Coast. We referenced Natural England’s SANG guidance as a suitable tool for assessing the amount and quality of provision and we are pleased that the proposed policy GC Policy 2: Nature specifically requires proposals to accord with this guidance. However, there is no information provided in the DPD (or supporting documents) on the overall size of the Garden Community land take; the size of the
likely developable area; or the amount of land that will be identified as Green Infrastructure (including the different typologies – recreation space; natural greenspace; allotments etc). Without this information it isn’t possible for Natural England to establish whether the SANG guidance can be met site-wide, and consequently whether the policy requirement is deliverable in practice. This
is an important consideration given that some reliance is being placed on the contribution to SANG
that can be made by Salary Brook Local Nature Reserve when, as yet, there is no information on the carrying capacity of the Nature Reserve. Based on a planned total of 7,500 dwellings, the SANG provision would amount to around 145 hectares of suitable, natural greenspace.

Delivery of mitigation required by HRA/AA in DPD Policy

1. Functionally Linked Land
The potential for the loss of functionally linked land (i.e. land which supports mobile species that are qualifying features of a European Sites) is identified as an issue to be progressed to Appropriate Assessment (AA) in the HRA that accompanies the DPD (undertaken by Essex Place
Services, dated May 2023). The European Sites of specific interest are the Colne Estuary
SPA/Ramsar and the Stour and Orwell Estuaries SPA/Ramsar.

As mitigation for such likely significant effects the HRA/AA states at 4.8.7:

“Each phase of development must be supported by up-to-date over-wintering bird surveys to determine the usage of the phases by individual waterbirds and the importance of their assemblages. If any over-wintering bird surveys at application stage identifies that the proposals will result in impacts upon the individual waterbirds or the waterbird assemblage associated within the Colne Estuary SPA and Ramsar site or the Stour and Orwell Estuaries SPA and Ramsar site,
then bespoke mitigation measures must be secured either by legal agreement or a condition of any consent with landowners located in Tendring District Council and Colchester City Council within
close proximity of the relevant Habitats sites.”

The reference to the need for wintering bird surveys only features in the “Justification” section for GC Policy 2: Nature and does not appear in the wording of this Policy or any other policies in the DPD. The wording of Policy 2 states that “proposals must be supported with appropriate ecological surveys” but this should be made more explicit to ensure that i) the Local Planning Authority can require that wintering bird surveys are undertaken ahead of the submission of relevant planning applications and ii) prospective developers are clear about the need for such surveys. Without explicit reference in the wording of the Policy there is scope for different interpretations at the application validation stage and there would remain some doubt as to a conclusion of No Adverse Effects on Integrity through HRA/AA of the Submission DPD.

2. Air quality impacts
The potential for the development of the Garden Community to have impacts upon air quality at certain European Sites is also identified as an issue to be progressed to AA. Assessment is
required due to the potential for the development (alone and in combination) to result in increases
in traffic levels on routes that lie within 200m of European Sites whose qualifying features, or the habitats that support them, are sensitive to any related changes in air quality.

The HRA/AA is specific about the need for traffic modelling to be undertaken to assess whether any mitigation for traffic-related impacts will be necessary. At 4.9.12 it states:

“Each relevant phase of development for the garden community should be supported by traffic scoping modelling to fully determine whether further mitigation measures to avoid adverse impacts from air quality are required…”

The HRA/AA goes on to outline the methodology that should be used for the modelling and identifies the trigger points for further air quality monitoring. A key traffic route to be considered in this context is the A137 which passes alongside the Stour and Orwell SPA/Ramsar. According to the HRA/AA, this route is expected to see an increase in annual average daily traffic (AADT), due to the Garden Community development, which exceeds the recognised trigger for potential likely significant effects (over 1,000 AADT increase).

In view of this anticipated increase, it would be reasonable for the AA to consider in more detail the specific circumstances at the relevant European Site to establish whether mitigation is required as a consequence of the proposed development (alone or in combination) because it doesn’t necessarily follow that a more than 1000 AADT will result in an adverse effect on site integrity.

The AA could consider (through site survey and APIS sourced information) the presence/absence of air quality (Nitrogen) sensitive habitat that exists within 200m of the relevant route; and if such habitats are present, the extent to which the qualifying features of the SPA are supported by such habitats. APIS-based information on trends in background pollution could also be examined to provide context. Some of this analysis appears to have been undertaken in the Screening section of the HRA/AA but the focus shifts in the AA to traffic scoping modelling and the results of traffic modelling (once compared with the air quality monitoring recently undertaken in connection with the Babergh, Mid Suffolk Joint Local Plan) is identified as the basis for assessing whether mitigation is required.
It is unfortunate that the air quality monitoring information is not yet available, nor is there any traffic modelling information available which would offer a more solid basis for ruling in/out individual European Sites at HRA screening stage. As a result, the mitigation that is identified
(4.9.12 and 4.9.13) does not provide mitigation per se; rather it requires traffic scoping modelling to establish whether there is the need for air quality monitoring which, in turn, may indicate that
mitigation is required. In any event, the requirement for traffic scoping modelling to be undertaken
ahead of each phase of the development does not appear in the text of any of the proposed
Policies in the DPD. If traffic modelling is being identified as the tool to be used to establish
whether mitigation will be required to avoid adverse effects on the integrity of European Site(s), the requirement for the modelling to be undertaken ahead of each phase of development needs to be
clearly set out in DPD policy.

In conclusion, Natural England advises that the screening for air quality impacts should be revisited once there is traffic modelling information available to confirm which European Sites merit consideration (due to exceedance of relevant AADT triggers) when the DPD is considered “alone” and “in combination”. Once that filter has been applied, consideration would shift to the Site-
specific circumstances as outlined above. Only at this stage will it become apparent whether mitigation is likely to be required and, if required, the mitigation options available can then be identified, tested and embedded in DPD Policy.

It is also worth noting that the APIS data has been recently updated and now provides a more fine- grained (1Km grid square) position on deposited Nitrogen at protected sites.

I trust that the above comments are helpful. I would be happy to comment further should the need arise but if in the meantime you have any queries, please do not hesitate to contact me at Tessa.lambert@naturalengland.org.uk

Natural England is a non-departmental public body. Our statutory purpose is to ensure that the natural environment is conserved, enhanced, and managed for the benefit of present and future generations, thereby contributing to sustainable development.

A number of modifications have been made to the DPD since the Regulation 18 consultation and many take into account the representations previously made by Natural England. There are, however, certain issues which require further consideration and clarification. These fall under the general headings of “Green Infrastructure Provision” and “Delivery of mitigation required by Habitats Regulations Assessment/Appropriate Assessment (HRA/AA) in DPD Policy”. Your attention is drawn to our advice on the HRA/AA of the potential effects of the DPD upon air quality at European Sites as this may require a more fundamental review.

Green Infrastructure Provision

Natural England has previously highlighted the need for the Garden Community to deliver sufficient Suitable Alternative Natural Greenspace (SANG) to mitigate the increased recreational pressure that the new housing will give rise to at the European Sites at the Essex Coast. We referenced Natural England’s SANG guidance as a suitable tool for assessing the amount and quality of provision and we are pleased that the proposed policy GC Policy 2: Nature specifically requires proposals to accord with this guidance. However, there is no information provided in the DPD (or supporting documents) on the overall size of the Garden Community land take; the size of the
likely developable area; or the amount of land that will be identified as Green Infrastructure (including the different typologies – recreation space; natural greenspace; allotments etc). Without this information it isn’t possible for Natural England to establish whether the SANG guidance can be met site-wide, and consequently whether the policy requirement is deliverable in practice. This
is an important consideration given that some reliance is being placed on the contribution to SANG
that can be made by Salary Brook Local Nature Reserve when, as yet, there is no information on the carrying capacity of the Nature Reserve. Based on a planned total of 7,500 dwellings, the SANG provision would amount to around 145 hectares of suitable, natural greenspace.

Delivery of mitigation required by HRA/AA in DPD Policy

1. Functionally Linked Land
The potential for the loss of functionally linked land (i.e. land which supports mobile species that are qualifying features of a European Sites) is identified as an issue to be progressed to Appropriate Assessment (AA) in the HRA that accompanies the DPD (undertaken by Essex Place
Services, dated May 2023). The European Sites of specific interest are the Colne Estuary
SPA/Ramsar and the Stour and Orwell Estuaries SPA/Ramsar.

As mitigation for such likely significant effects the HRA/AA states at 4.8.7:

“Each phase of development must be supported by up-to-date over-wintering bird surveys to determine the usage of the phases by individual waterbirds and the importance of their assemblages. If any over-wintering bird surveys at application stage identifies that the proposals will result in impacts upon the individual waterbirds or the waterbird assemblage associated within the Colne Estuary SPA and Ramsar site or the Stour and Orwell Estuaries SPA and Ramsar site,
then bespoke mitigation measures must be secured either by legal agreement or a condition of any consent with landowners located in Tendring District Council and Colchester City Council within
close proximity of the relevant Habitats sites.”

The reference to the need for wintering bird surveys only features in the “Justification” section for GC Policy 2: Nature and does not appear in the wording of this Policy or any other policies in the DPD. The wording of Policy 2 states that “proposals must be supported with appropriate ecological surveys” but this should be made more explicit to ensure that i) the Local Planning Authority can require that wintering bird surveys are undertaken ahead of the submission of relevant planning applications and ii) prospective developers are clear about the need for such surveys. Without explicit reference in the wording of the Policy there is scope for different interpretations at the application validation stage and there would remain some doubt as to a conclusion of No Adverse Effects on Integrity through HRA/AA of the Submission DPD.

2. Air quality impacts
The potential for the development of the Garden Community to have impacts upon air quality at certain European Sites is also identified as an issue to be progressed to AA. Assessment is
required due to the potential for the development (alone and in combination) to result in increases
in traffic levels on routes that lie within 200m of European Sites whose qualifying features, or the habitats that support them, are sensitive to any related changes in air quality.

The HRA/AA is specific about the need for traffic modelling to be undertaken to assess whether any mitigation for traffic-related impacts will be necessary. At 4.9.12 it states:

“Each relevant phase of development for the garden community should be supported by traffic scoping modelling to fully determine whether further mitigation measures to avoid adverse impacts from air quality are required…”

The HRA/AA goes on to outline the methodology that should be used for the modelling and identifies the trigger points for further air quality monitoring. A key traffic route to be considered in this context is the A137 which passes alongside the Stour and Orwell SPA/Ramsar. According to the HRA/AA, this route is expected to see an increase in annual average daily traffic (AADT), due to the Garden Community development, which exceeds the recognised trigger for potential likely significant effects (over 1,000 AADT increase).

In view of this anticipated increase, it would be reasonable for the AA to consider in more detail the specific circumstances at the relevant European Site to establish whether mitigation is required as a consequence of the proposed development (alone or in combination) because it doesn’t necessarily follow that a more than 1000 AADT will result in an adverse effect on site integrity.

The AA could consider (through site survey and APIS sourced information) the presence/absence of air quality (Nitrogen) sensitive habitat that exists within 200m of the relevant route; and if such habitats are present, the extent to which the qualifying features of the SPA are supported by such habitats. APIS-based information on trends in background pollution could also be examined to provide context. Some of this analysis appears to have been undertaken in the Screening section of the HRA/AA but the focus shifts in the AA to traffic scoping modelling and the results of traffic modelling (once compared with the air quality monitoring recently undertaken in connection with the Babergh, Mid Suffolk Joint Local Plan) is identified as the basis for assessing whether mitigation is required.
It is unfortunate that the air quality monitoring information is not yet available, nor is there any traffic modelling information available which would offer a more solid basis for ruling in/out individual European Sites at HRA screening stage. As a result, the mitigation that is identified
(4.9.12 and 4.9.13) does not provide mitigation per se; rather it requires traffic scoping modelling to establish whether there is the need for air quality monitoring which, in turn, may indicate that
mitigation is required. In any event, the requirement for traffic scoping modelling to be undertaken
ahead of each phase of the development does not appear in the text of any of the proposed
Policies in the DPD. If traffic modelling is being identified as the tool to be used to establish
whether mitigation will be required to avoid adverse effects on the integrity of European Site(s), the requirement for the modelling to be undertaken ahead of each phase of development needs to be
clearly set out in DPD policy.

In conclusion, Natural England advises that the screening for air quality impacts should be revisited once there is traffic modelling information available to confirm which European Sites merit consideration (due to exceedance of relevant AADT triggers) when the DPD is considered “alone” and “in combination”. Once that filter has been applied, consideration would shift to the Site-
specific circumstances as outlined above. Only at this stage will it become apparent whether mitigation is likely to be required and, if required, the mitigation options available can then be identified, tested and embedded in DPD Policy.

It is also worth noting that the APIS data has been recently updated and now provides a more fine- grained (1Km grid square) position on deposited Nitrogen at protected sites.

I trust that the above comments are helpful. I would be happy to comment further should the need arise but if in the meantime you have any queries, please do not hesitate to contact me at Tessa.lambert@naturalengland.org.uk