AC-2025-LON-000036 - [2025] EWHC 2701 (Admin)

Fecha: 21-Oct-2025

Flooding

35.

The major issue in the application for permission to appeal related to flooding and that is the issue raised in four of the identified grounds of appeal. At the oral hearing, Counsel for the Applicant focussed upon the issue of flooding and relied upon a case that had not been referred to in the grounds, or in the skeleton argument and had only been filed after court hours the day before the hearing. Unfortunately, as a copy had not been brought to court by the Applicant’s Counsel it was not before me at the oral hearing.

36.

Subsequent to the hearing, I have now familiarised myself with R (Substation Action Save East Suffolk Ltd) v Secretary of State for Energy Security and Net Zero (1) East Anglia One North Ltd (2) and East Anglia Two Ltd (3) [2024] EWCA Civ 12.

37.

The Inspector considered the issues surrounding flood risk within paragraphs 28 to 50 of the decision letter and concluded that there was a serious risk of flooding and that was the determinative issue in the appeal. In my judgment, he cannot properly be impugned with respect to his decision or the steps he took to reach that conclusion.

38.

The submissions on behalf of the Applicant were that Inspector had erred in determining the flood risk on the basis that the sequential test for flooding is with respect to all flooding and not just fluvial (i.e. from rivers and streams) and that he misunderstood the distinction as set out in the aforementioned Substation Save East Suffolk case.

39.

The Substation Save East Suffolk case concluded that an application for development consent is not required to demonstrate that whenever there is a risk of flooding from surface water that are no other sites reasonably available where the proposed development could be located in an area of lower surface water flood risk. The risks of flooding from surface water are to be taken into account when deciding whether to grant development consent and that raises issues of planning judgment. It is not a case that assists the Applicant in the circumstances of this case.

40.

The national guidance and the planning practice guidance (PPG) on “Flood risk and coastal change” provides a number of principles with respect to flooding:

That development should be directed away from areas at risk of flooding;

ii)

That if the development cannot be directed away from areas at risk of flooding then if the development is outside Flood Zone 1 (defined in table 1 of the PPG) then there is a sequential test to be applied in order that the development is steered towards lower-risk areas;

iii)

That if as a consequence of the sequential test being applied, a highly vulnerable development cannot be located in a lower risk area and the development will be in Flood Zone 2, then the exception test is to be applied and in order to satisfy that exception test it is necessary for the development to provide “wider sustainability benefits to the community” and that will be safe for its lifetime taking into account the vulnerability of its user.

41.

These principles arise from the National Planning Policy Framework (20 December 2023), which sets out as follows:

“165.
Inappropriate development in areas at risk of flooding should be avoided by directing development away from areas at highest risk (whether existing or future). Where development is necessary in such areas, the development should be made safe for its lifetime without increasing flood risk elsewhere.
168.
The aim of the sequential test is to steer new development to areas with the lowest risk of flooding from any source. Development should not be… permitted if there are reasonably available sites appropriate for the proposed development in areas with a lower risk of flooding. The strategic flood risk assessment will provide the basis for applying this test. The sequential approach should be used in areas known to be at risk now or in the future from any form of flooding.
169.
If it is not possible for development to be located in areas with a lower risk of flooding (taking into account wider sustainable development objectives), the exception test may have to be applied. The need for the exception test will depend on the potential vulnerability of the site and of the development proposed, in line with the Flood Risk Vulnerability Classification set out in Annex 3.
Annex 3 contains the “Flood risk vulnerability classification”. Which included “Caravans, mobile homes and park homes intended for permanent residential use” in the “HIGHLY VULNERABLE” category.
170.
The application of the exception test should be informed by…a site specific flood risk assessment. To pass the exception test it should be demonstrated that: a) the development would provide wider sustainability benefits to the community that outweigh the flood risk; and b) the development will be safe for its lifetime taking account of the vulnerability of its users, without increasing flood risk elsewhere, and, where possible, will reduce flood risk overall.
171.
Both elements of the exception test should be satisfied for development to be allocated or permitted.”

And from the PPG which provides as follows:

“The [sequential] approach is designed to ensure that areas at little or no risk of flooding from any source are developed in preference to areas at higher risk. This means avoiding, so far as possible, development in current and future medium and high flood risk areas considering all sources of flooding including areas at risk of surface water flooding.”
“The Sequential Test… will not be required where… The site is in an area at low risk from all sources of flooding…”
“The absence of a 5-year land supply is not a relevant consideration for the sequential test for individual applications.”
“The Exception Test should only be applied… if the Sequential Test has shown that there are no reasonably available, lower-risk sites, suitable for the proposed development, to which the development could be steered.”
“Examples of wider sustainability benefits to the community could include:
The re-use of suitable brownfield land as part of a local regeneration scheme;
An overall reduction in flood risk to the wider community through the provision of, or financial contribution to, flood risk management infrastructure;
The provision of multifunctional Sustainable Drainage Systems that integrate with green infrastructure, significantly exceeding National Planning Policy Framework policy requirements for Sustainable Drainage Systems;”

42.

Further, Table 1 defines Flood Zone 1 (“FZ1”) as “Land having a less than 0.1% annual probability of river or sea flooding”, FZ3a as “Land having a 1% or greater annual probability of river flooding”, and FZ3b (the functional floodplain) as “land where water from rivers or the sea has to flow or be stored in times of flood… Functional floodplain will normally comprise land having a 3.3% or greater annual probability of flooding, with any existing flood risk management infrastructure operating effectively”. Table 2 makes it clear that highly vulnerable development in FZ1 need not satisfy the exception test, and that such development should not be permitted in FZ3a/b, without reference to the exception test.