WHAT’S UP IN WEALDEN?
WDC’S CONSIDERATION OF NITROGEN DEPOSITION
IN THE PLANNING PROCESS AND JUDICIAL
hankinson duckett associates
Ashdown Forest SAC
- 2729 ha in East Sussex
- Designated on basis of wet and
dry lowland heathland habitats
- Sensitiveto eutrophication
through nitrogen deposition
- Crossed and bordered by
several major roads including the
Image taken from Lewes District Council HRA
Core Strategy Local
- Supports use of Design Manual for Roads
and Bridges (DMRB) methodology
- DMRB test scopes out development that
results in <1000 Annual Average Daily Traffic
- WDC identify increase of 950AADT on 275m
stretch of A26 – ‘the Critical Link’ as a result
of the Core Strategy
- Core Strategy Inspector considers this to
leave “very little headroom” for further
development, and requires further research
- Initial findings of research due in 2017
- 103 homes 2.4km from Ashdown Forest SAC
- WDC concede no impact ‘alone’ and issue
relates to traffic on the A26 ‘critical link’ only.
- AADT on critical link is only 43 so DMRB test
passed (still only 993 AADT with WDC traffic)
- Nitrogen modelling confirms deposition arising
is <1% critical load on all roads.
- Inspector grants planning consent but takes
“more precautionary approach” than Natural
England (para 70) and takes into account
‘heathland management contribution’ to arrive
at the project having “a significant beneficial
effect on biodiversity in the AF and so also
offsetting any small chance of harm as a result
of N deposition.” (para 68)
- PIns ref: APP/C1435/A/14/2223431
Steel Cross Judicial Review
- Despite the Steel Cross Scheme doing more to demonstrate no likely
significant effect than their entire Core Strategy, WDC decide to JR the
- WDC’s case was largely related to ambiguous wording in the Inspector’s
- WDC argued confusion by Inspector in reference to the heathland
management contribution as ‘SAMMS’ (which eventually related to mitigation
for recreational pressure in Wealden)
- Court of Appeal ruled that if the Inspector was relying on SAMMS or
Heathland Management Contribution, then he had insufficient evidence to
guarantee its implementation/ efficacy.
- Ref: Wealden DC v SSCLG  EWCA Civ 39
Some smaller development allowed where no
net gain in AADT
▪ Land West of Culpepper Close (WD/2016/1718/MAO) – Development of 10
homes offset increase in nitrogen against closure of local pub 1.5 years
previously to demonstrate 950 AADT on critical link not exceeded.
▪ Some smaller schemes granted planning permission on similar basis
(e.g. April Cottage – a former doctor’s surgery)
▪ WDC issue note in March 2017 ‘Briefing Document for the Ashdown Forest
Nitrogen Deposition position – 13th March 2017’
▪ WDC recognise that critical loads are already exceeded adjacent to many
▪ WDC move towards assessment of revised local plan using Environment
Agency’s 1% of critical load threshold.
▪ WDC identify that all development would exacerbate a current issue and
therefore all development must either:
1. Demonstrate no net gain in emissions
on roads crossing the SAC; or
2. Provide mitigation or compensation.
WDC are exploring a strategic approach
High Court hearing: WDC v. SoS, LDC, SDNP & NE
▪ WDC initiated judicial review of the Joint Core Strategy (JCS) of LDC and SDNP.
▪ Principle Issue: Whether LDC and the SoS 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 SAC, in combination with the Wealden Core Strategy.
▪ WDC’s case rested on the AADT of the A26 critical link being exceeded by the JCS
AADT of 190 with WDC’s 950 AADT, arguing that the JCS had not been subject to an
in combination assessment.
▪ Mr Jay J did not appear aware of most widely accepted use of DMRB (and that of
Natural England) to identify whether there is need for further assessment to establish
potential for a likely significant effect to arise (e.g. para 12).
▪ Mr Jay J subsequently takes approach that in using DMRB methodology in-
combination effects should be considered from the outset.
▪ Whilst recognising that thresholds can be used by a competent authority, he does not
identify an alternative to that provided by the DMRB or 1% rule (para 53).
▪ Mr Jay J’s judgment was handed down in March 2017, effectively quashing the Joint
Core Strategy where it relates to development within the SDNP.
▪ My Jay J subsequently recommends that (1) Natural England reconsider its advice in
light of his judgment and (2) the DMRB is re-examined and clarified.
What does this teach us?
1. We need a robust, clearly worded methodology to identify plans or projects
which have potential to result in cumulative effects on designated sites
thereby requiring further investigation.
2. Further investigation should, if appropriate, be clearly separated from
‘appropriate assessment’ (where a likely significant effect has been
3. Use of the methodology should be fully supported by statutory nature
conservation and environmental consultees.
4. Where the methodology is tested at appeal, public inquiry and court
hearings, appropriately qualified practitioners should be present to guide
advocates, Inspectors and Judges.