Judgment was handed down yesterday in Wealden District Council v Secretary of State for Communities and Local Government, Lewes District Council and South Downs National Park Authority  EWHC 351 (Admin), which was challenge to quash part of the Lewes Joint Core Strategy, as jointly prepared by LDC and the Authority. The case concerned the approach to in-combination assessments pursuant to the Habitats Regulations.
The principal issue was whether LDC and the Authority had acted unlawfully in concluding, on advice from Natural England, that the JCS would not be likely to have a significant effect on the Ashdown Forest Special Area of Conservation, in combination with the Wealden Core Strategy, pursuant to the Habitats Regulations. The environmental effect in question was the impact from vehicle emissions on nitrogen deposition in the heathland within the SAC. Relevant to this question was advice from the then Highways Agency, in the Design Manual for Roads and Bridges, which stated that where annual average daily traffic movements (AADT) resulting from development did not exceed 1000 on affected roads, environmental effects could be regarded as neutral and “scoped” out of any further assessment.
Wealden District Council argued that whereas its Core Strategy had been prepared on the basis that it would generate 950 AADT on part of the A26 road next to the SAC, the effect of the JCS would be to increase the AADT beyond the 1000 threshold and on a proper interpretation of the DMRB guidance, this required an in-combination assessment of the effects of both the Wealden Core Strategy and the JCS which had not been carried out in the Habitats Regulations Assessment (HRA) associated with the preparation of the JCS. LDC and the Authority argued that no in-combination assessment was required because the JCS on its own involved the generation of traffic below the threshold on its own and applying the guidance, no further in-combination assessment was required.
The Secretary of State also referred to separate guidance relied upon by Natural England and prepared by the Air Quality Technical Advisory Group (AQTAG), to the effect that the 1,000 AADT threshold equated to a 1% change in critical loads/levels relating to an identified pollutant which, if not exceeded, allowed the decision-maker to conclude that there was no likely significant effect. The advice also stated that experience of permitting allowed the Group to be “confident that it was unlikely that a substantial number of plans or projects will occur in the same area at the same time, such that their in-combination impact would give rise to concern at the appropriate assessment stage. If such a situation was [sic] to arise then the assessment could be determined on a case-specific basis”. Wealden District Council argued that this confirmed the unlawfulness of the approach taken to the HRA.
Jay J found that on a proper interpretation of the DMRB, at least in principle, in-combination effects are potentially relevant at the initial “scoping” stage as well as the subsequent stage requiring further assessment.
It was also concluded that advice from Natural England to LDC and the Authority on the approach to be taken to the HRA, which relied on the AQTAG guidance, was “plainly erroneous”:
“92…On the facts of the instant case, it is not a question of a couple of minor developments or projects being sought to be taken in combination, but a Core Strategy covering a twenty-year period which has already assessed the impact of additional traffic flows on an SAC within its borders. There is no sensible or logical basis for excluding the WCS from account. The final sentence of the cited passage states that were there to be a substantial number of other plans these should be taken into account on a case-specific basis…[I] n a case where the relevant AADT levels referable to two plans are known, the logic of the final sentence indicates that these should be considered in tandem.
93. The point may be tested in this manner. If the HRA for the WCS had stated that the modelled AADT value was 1,050 rather than 950…an “appropriate assessment” would have had to be made at the second stage: in other words, that these impacts could not be regarded as de minimis, or neutral, or be removed from scope. However artificial it may be to take a fixed threshold, and however minor in reality any predicated environmental impact may be,… the assessment would have to proceed to the next stage. This would be the case, therefore, despite the 1,000 AADT level being robust and extremely precautionary. In my judgment, there may be no distinction logically to be made between 1,050 additional traffic flows from one district and 1,050 (on our figures, in fact 1,140) additional traffic flows from two districts. The cars are the same and the nitrogen dioxide is the same”.
It was therefore held that the HRA was vitiated by Natural England’s advice, because LDC and the Authority should have undertaken further inquiry of Natural England in circumstances where no explanation had been given for not aggregating the two amounts; and because Natural England’s error directly infected the decision-making process. Jay J added that “Natural England must reconsider its advice in the light of this judgment. Further, I direct that the Government Legal Department send a copy of this judgment to Highways England: the DRMB should be re-examined, and clarified, to reflect the concerns I have indicated”.
Jay J also held that in circumstances where LDC and the Authority adopted the JCS on different dates, Wealden District Council was out-of-time to challenge the adoption by LDC, but in time to challenge the adoption by the Authority. The relief granted was the quashing of relevant housing policies in the JCS insofar as they formed part of the development plan for the administrative area of the Authority. As regards LDC, the judgment would have declaratory effect, such that it would be relevant to the weight given to those policies and to the decision whether an appropriate assessment was required for individual planning applications pursuant to the Habitats Regulations.
John Hobson QC and Scott Lyness appeared on behalf of Wealden District Council.
Richard Moules appeared for the Secretary of State.
A copy of the judgment can be found at here.