England and Wales High Court (Administrative Court) Decisions

IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
ADMINISTRATIVE COURT

		Cardiff Civil Justice Centre 2 Park Street Cardiff, CF10 1ET
		01/11/2013

Mr Justice Cranston:

Introduction

1. This is an application under section 288 of the Town and Country Planning Act 1990 ("the 1990 Act"). The first claimant is Castletown Estates Ltd ("Castletown"), a property developer; the second claimant is Carmarthenshire County Council ("the Council"). Ms Morag Ellis QC represented Castletown; Mr Beglan, who represented the Council, adopted her submissions. The claimants challenge the decision of the Welsh Ministers in March this year to refuse to grant outline planning permission for the redevelopment of ex industrial land at Burry Port as a residential area with retail space and landscaping ("the site"). In his separate submissions Mr Beglan underlined that the Council is especially concerned with the regeneration benefits which development of the site will bring.
2. In essence the claimants contend that the Welsh Ministers were in error because they proceeded on the basis of inaccurate flood and development advice maps that showed that the site was at risk of flooding, whereas the position agreed with Natural Resources Wales (formerly the Environment Agency Wales, formerly the Environment Agency), that the site was not at risk of flooding. The concern in relation to this site is with tidal, not fluvial, flooding. The claimants also raise a procedural issue of how the Welsh Ministers reached their decision. Ms Ellis QC stated that the issues in this case are of significance for other potential developments in Wales (and also England).

The planning application: background

3. Castletown's planning application sought outline planning permission on the former Grillo Zinc Oxide Works site, at Burry Port Harbour, Burry Port, for comprehensive mixed-use redevelopment. The application site lies within the defined development limits of Burry Port and is designated as part of the Burry Port harbour strategic regeneration area under the Council's planning policies. There was to be residential development of up to 230 dwellings and 465m² of retail/leisure floor space, the creation and alteration of vehicle and pedestrian access, landscaping, public open space, remediation and associated works on the site.
4. Natural Resources Wales produce flood maps which show, amongst other things, extreme flood outlines – areas of land that would be flooded should there be an extreme flood, i.e. land in respect of which there is a 0.1% chance that it will flood in any given year. These flood maps deal with the situation at the time of drafting, without reference to climate change and rising sea levels. They are updated on a regular basis. In emails on 31 January 2013 the team leader for flood risk analysis at Natural Resources Wales accepted that it would be unable to meet the deadline for updating the flood map for Burry Port because of other resource priorities, although it would consider map challenges. He added that he was concerned that Burry Port was not properly represented on the flood map. Updated hydrology would need to be run through the models. Natural Resources Wales were aware that the Council had commissioned a flood consequences assessment of Burry Port and "we will of course try to utilise this data when we receive it to update [the] flood map".
5. The Welsh Ministers use these flood maps, amongst other data, to produce development advice maps ("DAMs"). These define three zones: zone A, land where there is little or no risk of flooding; zone B, land which is known to have been flooded in the past; and zone C, land in respect of which there is a 0.1% chance that it will flood in any given year (i.e. the extreme flood outlines on Natural Resources Wales' flood maps). Zone C is subdivided into zone C1, areas served by significant infrastructure, including flood defences, and zone C2, areas without significant flood defence infrastructure. Development advice maps were first published in 2004, and revised versions in 2009 and 2013.
6. Throughout the whole period of the planning application the flood maps have shown the extreme flood outline running across the site – it is a straight line at one point. The relevant DAM has a significant part of the site within zone C2, the remainder within zone A.
7. Alan D Wilkinson and his firm, Waterman Transport and Development Ltd, were engaged to assist in the preparation of a planning application for the site. Mr Wilkinson is an engineer. As part of this task the firm undertook a hydrological assessment of the site dated 31 January 2006. In March 2006 the firm prepared a flood consequences assessment for the previous owner, which in May 2006 was presented to Castletown after it had bought the site. That assessment was revised in August 2010 to take account of new advice issued by the Department of Environment, Food and Rural Affairs ("Defra") on how climate change over time may influence sea level rises, rainfall intensity and extreme wave heights. The assessment concluded:

"With regard to the risks associated with tidal flooding:

The existing site has been shown to be affected by 0.5% and 0.1% probability tidal events considering future sea level rise to 2112.

It is proposed to raise ground levels within the site to a minimum of 6.85m AOD (the 0.5% probability level), which satisfies TAN15's [Technical Advice Note 15] threshold of flooding criteria.

The maximum depth of flooding to the proposed development in a 0.1% probability tidal event would therefore be 200mm, which complies with TAN15.

Safe emergency access/egress is available via the Southern Distributor Road."

8. Mr Wilkinson had sent his hydrological assessment to Natural Resources Wales in early 2006. On 17 February 2006 Mr Steve Allison, a technical specialist and qualified engineer at Natural Resources Wales, emailed that "[W]e must concur with your findings" in relation to the assessment that mixed use development on the Grillo site was not considered to be at risk from extreme tidal flood events. At the conclusion of the email Mr Allison noted that Natural Resources Wales had not checked the data itself.
9. Castletown applied to the Council for outline planning permission on 26 March 2008. On 4 November 2010 Natural Resources Wales wrote to the Council about the development. The letter referred to Mr Wilkinson's 2010 flood consequences assessment. The site would still be at risk of flooding in the 0.1% tidal event with a climate change allowance, but current guidance stated that climate change allowances needed only to be assessed on the relevant thresholds in A1.14, not A.15, of appendix 1 of TAN15. The flood consequences assessment therefore concluded that the proposed development would comply with TAN15. Based on the information submitted, the letter continued, Natural Resources Wales considered that the conclusions appeared reasonable and therefore had no adverse comments with regard to flood risk. However, the Council should liaise with other appropriate bodies regarding access routes.
10. In mid-January 2011 the Council indicated that it was minded to approve the application.

Relevant planning policies

11. Policy GDC30 of the Carmarthenshire Unitary Development Plan ("UDP"), the statutory development plan, provides that all developments in areas of flood risk are to be determined in accordance with the following criteria:

"1. Highly vulnerable development and/or emergency services within Zone C2 will not be permitted:

2. Highly vulnerable development and/or emergency services within Zone C1 and/or other development within Zone C will only be considered where it can be demonstrated that:

it concurs fully with the justification specified in section 6 of TAN15. In particular, the site complies with the definition of previously developed land (PPW figure 2.1);

an appropriate flood consequences assessment has been completed and approved."

The policy then deals with development within Zones A and B. The notes to the policy explain that the zones referred to in it are those referred to in Technical Advice Note 15, Development and Flood Risk ("TAN15"), which is a supplement to Planning Policy Wales.

12. Planning Policy Wales was intended when published in 2002 to set the context for sustainable land use planning policy, within which local planning authorities' statutory development plans are prepared, and development control decisions on individual applications and appeals taken. In respect of minimising and managing environmental risks and pollution it stated that, among other things:

"Meeting the Assembly Government's objectives for sustainable development requires action through the planning system to move away from flood defence and the mitigation of the consequences of new development in areas of flood hazards towards a more positive avoidance of development in areas defined as being of flood hazard."

Under the heading "Development management and flood risk", Planning Policy Wales states that it is essential that the advice of Natural Resources Wales is obtained and given due weight as a material consideration by planning authorities and must have good reason for not following it. The policies in Planning Policy Wales are supplemented by TAN15.

13. TAN15 is concerned with flood risk over the design life of a development. It notes that floods occur relatively infrequently but that their consequences can be very significant in placing lives at risk, causing considerable personal trauma and resulting in extensive property damage: [2.1]. Its precautionary framework allows flooding to be accorded appropriate consideration, while recognising that development will continue to be necessary in coastal areas. Problems due to flooding may be increasing in frequency and scale. Development should be avoided in areas where the consequences of flooding will be unacceptable. Climate change should be taken into account. Its aim is stated as follows:

"3.1 The general approach of [Planning Policy Wales], supported by the TAN, is to advise caution in respect of new development in areas at high risk of flooding by setting out a precautionary framework to guide planning decisions. The overarching aim of the precautionary framework is, in order of preference, to:-

• Direct new development away from those areas which are at high risk of flooding.

• Where development has to be considered in high risk areas (zone C) only those developments which can be justified on the basis of the tests outlined in section 6 and section 7 are located within such areas.

3.2 The operation of the precautionary framework is governed by:-

• A development advice map containing three zones (A, B and C with subdivision into C1 and C2) which should be used to trigger the appropriate planning tests in relation to sections 6 and 7 and appendix 1.

• Definitions of vulnerable development and advice on permissible uses in relation to the location of development and the consequences of flooding.

3.3 The precautionary framework should be used for both forward planning and development control purposes."

Section 3.4 continues that developers need to demonstrate that they meet the tests and Natural Resources Wales should assist a planning authority to come to a decision. Section 4.3 reads that the DAMs are robust for triggering the application of the tests it sets out, but it is inevitable the information will change over time.

14. Section 6 of TAN15 provides that new development should be directed away from zone C. In particular highly vulnerable development (residential) should not be permitted in zone C2. If it is to be in zone C1 it should only be permitted if it meets the tests in Appendix 1 regarding assessments of flood mechanisms and consequences (paragraph 6.2). Appendix 1 highlights that the first step in undertaking an assessment is to consult Natural Resources Wales about its objectives of the assessment. The appendix cautions that levels of confidence in estimating flood events are generally not high and that they are also likely to be affected by global warming and climate change. The high costs of flooding require a precautionary approach. The uncertainties must be taken into account to ensure sensible and pragmatic decisions. A proposed development must provide a safe and secure living and/or working environment throughout its life. Amongst other things descriptions of flooding consequences for a site should include likely mechanisms of flooding; its likely sources; the depths of flooding; the speed of inundation; and the rate of rise and velocities of flood waters.
15. A1.14 of appendix 1 addresses the frequency of flooding. It invokes Natural Resources Wales' advice that a development should be flood free during the 0.5% tidal/coastal flood, i.e. a 1 in 200 chance in any year event. That is the indicative threshold frequency of flooding below which flooding of the development should not be allowed. The 0.5% threshold applies to tidal floods and residential, commercial/retail and industrial development.
16. Appendix A1.15 deals with the severity of flooding. It states that beyond the threshold frequency proposed development would be expected to flood under extreme conditions, but even with adequate mitigation it may still not be sensible for development when the velocity and depth of flood waters were such that structural damage was possible or people could be swept away. Similarly, it would not be sensible for single story residential development when the depth of flooding would exceed 0.6 metres. A1.15 then has a table with indicative figures in four columns: (1) maximum depth of flooding (mm) (property access); (2) maximum rise of flood waters (metres per hour); (3) maximum speed of inundation of flood risk (hours); (4) maximum velocity of floodwaters (metres per second) (property access). Later the appendix refers to best estimates of the impact of climate change on probabilities.
17. In November 2006, the then Welsh Minister responsible for planning, Carwyn Jones AM, issued clarification letter CL-09-06 in relation to flood risk, TAN15 and the key role of Natural Resources Wales in this. Developers, local planning authorities and Natural Resources Wales were expected to co-operate to ensure that development plan allocations and development decisions were based on a clear understanding of flood risk. The agency would make its expertise available. The Minister only expected the agency to object to a development where it was appropriate to do so in flood risk management terms, rather than as a matter of principle. It may, not will, object when the consequences of a flood risk event cannot be acceptably managed in terms of the risk to people and property.

The public inquiry

18. The Welsh Ministers called in the planning application for their own determination under section 77 of the 1990 Act on 1 March 2011. They appointed Emyr Jones as the planning inspector to report on the application. Mr Jones is a qualified engineer. The reason given for the call in direction was that the application raised planning issues which might be in conflict with national planning policies in respect of flooding, and therefore the application appeared to raise issues of more than local importance. The matters on which the Ministers particularly wished to be informed included the relevant national policies relating to flooding issues as set out in Planning Policy Wales and TAN15. The public inquiry was held on 13 and 15 December 2011; there was a site visit on 14 December 2011.
19. Before the planning inspector Mr Wilkinson gave evidence on Castletown's behalf. His proof of evidence was that, although the site was shown as falling within the extreme flood outline on flood maps of Natural Resources Wales and the DAM, it was at a level which meant that there was a less than a 0.5% or a 0.1% chance that the site would flood in any given year. This was based on his firm's hydrological assessment, which Natural Resources Wales had accepted. He had concluded that the flood maps and the DAMs were incorrect. Mr Wilkinson told the planning inspector that when climate change and rises in sea levels were factored in, in accordance with new Defra guidelines, the site was vulnerable to flooding if there was a 0.5% or a 0.1% tidal flood. He proposed mitigation measures by raising the ground level of the development to a minimum of 6.85m AOD, the 0.5% probability level, "which satisfies TAN15 threshold". The site would still flood if there was a 0.1% flood but the maximum depth of that would be 200mm, "which complies with TAN15 recommendations". Mr Wilkinson told the inspector that assessments of the actual vulnerability of the site to flooding should be made on a site-specific basis. He said that TAN15 adopted a precautionary approach to flood risk. He described it as generally an excellent document which provided a framework for the evaluation of risk.
20. The planning inspector asked Mr Wilkinson about the suggestion of Natural Resources Wales, in its 4 November 2010 letter, that its policy was not to take account of the effect of future climate change and rising sea levels when considering Appendix A1.15 of TAN15. In response Mr Wilkinson submitted a Note that the projected 0.1% tidal level, including Defra climate change, was 200mm above the defined threshold level. In this case the building slabs would flood to a depth of 200mm but that was within the tolerance of 600mm stated in TAN15. No further mitigation measures would be necessary to accommodate this additional risk. The letter from Natural Resources Wales suggested that although climate change should apply to the threshold levels it would not need to extend to the 0.1%. Mr Wilkinson said that he had discussed this with Natural Resources Wales and understood that this was dispensation agreed on account of inaccuracies in defining the 0.1% event flood. The Note added:

"As a policy we tend to consider climate change when considering 0.1% events because this provides a robust solution to flood risk. It is interesting to note however, that [Natural Resources Wales] have relaxed their policy in respect of the 0.1% event. The matter has however no relevance in terms of the current application. With regard to Table 1.15 of TAN15 this contains a series of limiting parameters which would apply regardless of whether climate change applies to the return period floods or not."

21. The Council supported Castletown's application before the planning inspector. One aspect of its case related to the conflict of the development with planning policy GDC30. It submitted that TAN15 at paragraph 6.2, when properly interpreted, did not constitute an absolute bar to residential development in C2 flood risk areas. That interpretation issue is no longer live before me. The Council then adopted Mr Wilkinson's evidence, that the Welsh Government's development advice maps could not be relied upon. The most reliable evidence of flooding should be given precedence. That was the flood consequences assessment by Mr Wilkinson's firm, which Natural Resources Wales had approved. The flood risk could be justified for this development on the basis of the assessment and the conditions proposed in relation to the minimum levels of the development site, to be raised to a minimum 6.85m AOD.
22. Natural Resources Wales made written representations to the inspector. Mr Allison from the agency also appeared and answered the inspector's questions on flooding. Another agency official, Mr D Watson, participated in the session on planning conditions. Natural Resources Wales did not instruct counsel at the inquiry. Its written representations noted that the application had been ongoing since April 2008 and during that time Natural Resources Wales had raised a number of matters, including flood risk. The developer had addressed them directly or they could be resolved by the imposition of planning conditions. Natural Resources Wales stated that it had no comments on adverse flood risks following the revised flood consequences assessment by Mr Wilkinson's firm.
23. The planning inspector reported favourably on 23 January 2012. Having regard to the matters raised by the Welsh Ministers, he identified as a "main consideration" whether there were material considerations sufficient to outweigh any conflict with planning policies seeking to prevent highly vulnerable development in areas of the floodplain without significant flood defence infrastructure. (The other two "main considerations" the inspector identified have no relevance to this litigation). His conclusions in relation to this matter began with the recognition that, since it included residential development within zone C2 on the DAMS, the proposal clearly conflicted with UDP policy GDC30 and TAN15 advice: [111]. He then stated, in a passage which assumed some importance in the context of this litigation:

"112. The evidence submitted demonstrates that the flood outline shown on the DAMs is tidal rather than fluvial. It also shows that the site is not at risk of tidal flooding in either a 0.5% or 0.1% flood event with a 50 year design life and sea level rises based on TAN15 criteria. Whilst the site would be liable to flooding in such events with a 100 year design life and revised Defra climate change guidelines, the proposed ground raising would result in the proposal being flood free in a 0.5% probability event. Flood depths in a 0.1% probability event would be 200mm, which is much less than the maximum of 600mm cited in appendix 1 of TAN15, with a flood free escape route being available via the southern distributor road. The site would be in a hydraulic continuity with the harbour and estuary in extreme events and [Natural Resources Wales] accepts that any potential effect of the land raising on existing property would be negligible. I have no reason to disagree and conclude that loss of floodplain storage would not exacerbate conditions elsewhere."

For these reasons, the inspector said, with mitigation there would be no unacceptable flood risk. He added that it was also of some significance that, having reviewed the revised hydraulic model and the updated flood consequences assessment, Natural Resources Wales, whose advice should be given due weight under Planning Policy Wales, had no adverse comments with regard to flood risk: [113]. Thus the development could be justified on the site, since it would not be at risk of flooding in a 0.5% probability event and would provide tolerable conditions in a 0.1% probability event: [116].

24. In paragraph [117] the inspector turned to TAN15. It acknowledged that some flexibility was necessary to enable the risks of flooding to be addressed, while recognising the negative economic and social consequences if policy were to preclude investment in existing urban areas and the benefits of reusing previously developed land. The matters he had outlined in paragraphs 112-116 were all material considerations in support of the proposal.

"In my view when taken together, they are sufficient to outweigh the identified conflict with planning policies which seek to prevent residential development in zone C2 and justify a degree of flexibility in recognition of the benefits of investing in this previously developed and contaminated urban site": [117].

25. To ensure that the development would be flood free in a 0.5% probability event with climate change, the inspector recommended as one of 17 conditions attached to planning permission this condition:

"17. The final site levels shall be set no lower than 6.85m AOD and ground floor levels to residential properties shall be set at least 600mm above the final site level."

26. Following the public inquiry, Castletown's representatives pressed the Minister as to when a decision would be made. In mid-April 2012, an official informed the claimant that the delay was attributable to the complex issues involved, not involving planning. Later in the year Castletown's representatives sent further letters pressing for a decision and offering assistance. At one point in these proceedings it was suggested that, after the inquiry, there was contact between the Welsh Ministers and Natural Resources Wales regarding the flood map, the development advice map, or the planning application in relation to the site. I accept the evidence of James Hooker, a senior planning manager in the Welsh government, that there was no such contact.

The decision letter

27. The Minister issued the decision letter on 21 March 2013. He disagreed with the planning inspector and did not accept his recommendation about granting planning permission for the proposed development. After quoting the passage from Planning Policy Wales set out above in paragraph 12 of this judgment, the decision letter turned to TAN15. It referred to the precautionary framework in section 3 and the approach to development in zone C (and zone C2) in section 6. The DAM for the site, the decision letter said, placed it within zone C2: [11]. Later the decision letter said of the maps.

"[14] The Minister has noted the submissions made during the inquiry about the DAMs being incorrect. The DAMs are those that were released in 2009 and Welsh Government officials have been meeting with [Natural Resources Wales (NRW) regularly (bi-annually) since 2010 to discuss the need to update DAMs on an all Wales basis if [NRW's] flood maps show significant changes.

To date [NRW] has not informed the Welsh Government that there have been significant changes in this vicinity that would warrant revising the DAM for the application site. Changes to the DAMs are undertaken on the basis of validated changes to [NRW's] flood map. The latest [NRW] flood map data was released in 2013 and informed updated DAMs were issued on 4 March 2013. The [NRW] data shows no change has occurred on the site, i.e. the application site remains in zone C2."

28. In the immediately preceding paragraph to this, the Minister agreed with the inspector that the proposal was in conflict with planning policies: [13]. He turned to whether material considerations outweighed the policy conflict: [15]. Natural Resources Wales had no adverse comments with regard to flood risk and that had to be given due weight as a material consideration: [17]. Natural Resources Wales assessed the site against Appendix A1.14 of TAN15 and the flood consequences assessment (which built in a factor for climate change). The Minister noted the inspector's observation that the policy of Natural Resources Wales was to take into account sea level rises with Appendix A1.14, but not Appendix A1.15 and that, in recognition of this, the claimant intended to raise finished floor levels to be above the 0.5% probability tidal event with 100 year's worth of sea level rises: [18]. The Minister pointed out that Policy GDC30 is based on TAN15, which is based on a precautionary approach, the overarching aim of which is to direct new development away from areas which are at high risk of flooding. Highly vulnerable development should not be permitted in zone C2: [19]. The decision letter then said:

"[20] The Minister does not consider that the tests in section 7 of, and Appendix A1.14 and A1.15 to, TAN15 are applicable to highly vulnerable development in zone C2. He has noted, however, that the inspector has used them as an aid to assessing actual flood risks as part of the balancing exercise in determining whether any material considerations, individually or collectively, outweigh the policy conflict identified in paragraph 13 above."

29. The decision letter turned to residential development in zone C1 (it is not permissible in zone C2): Appendix A1.14 set threshold tests for flooding in extreme circumstances, and Appendix A1.15 then set out four additional tests: [21]. The decision letter continued:

"[22] The applicant has submitted that, the proposed site would, if raised, satisfy the tests in Appendix A1.14. The question then is whether the four tests in Appendix A1.15 – maximum depth of flooding; the maximum rate of rise of floodwaters in metres per hour; the maximum speed of inundation in hours; and the maximum velocity of floodwaters – have also been addressed. The Minister has reviewed the Flood consequences Assessment (FCA) (August 2010), which is an update of the original FCA (May 2006) and considers that it does not address all four of those tests. In this respect he notes that [NRW] does not state that the FCA (August 2010) does do this, limiting its view to being a view based on the information presented to it, nor does [NRW] express a view on whether the proposed development would satisfy all the tests in Appendix A1.15.

[23] The Inspector considers that if the site was raised, it would satisfy the threshold set out in Appendix A1.14 to TAN15 in that it would be below the risk of 0.5% tidal flooding. Furthermore, he considers that it would still be at risk of flooding in extreme conditions, but the flood depths would be at less than the 600mm shown in Appendix A1.15 to TAN15 for residential properties. The Minister notes that the inspector does not, however, refer to the other three tests in Appendix A1.15 in reaching his conclusion or indicate that they have been taken into consideration. In view of this the Minister does not consider that he could reasonably agree with the Inspector's conclusion that there would not be any unacceptable risk of actual flooding if there was mitigation."

30. In the light of that, the decision letter read, considerable weight had to be attached to UDP policy GDC30 in considering whether other material considerations justified a departure from it: [24]. The decision letter mentioned paragraphs [112]-[116] of the inspector's report, where he set out the benefits which he saw as material considerations to justify a departure from the development plan: [26]. The decision letter then referred to the regeneration benefits: [27]-[29]. The site was within zone C2, although the claimant had submitted that the map was wrong: [30]. The Minister did not consider that there were material considerations outweighing the conflict with planning policies relating to the prevention of highly vulnerable development in areas of the floodplain without significant flood defence infrastructure: [38].

The claimant's case

31. Fundamental to the claimants' case was what Ms Ellis QC submitted was the incorrect classification of the site as C2. Following the hydrological study and in the 2006 flood consequences assessment Mr Wilkinson had said that the flood map and the DAM were wrong in this respect. Natural Resources Wales agreed with him in 2006 and, following later work in connection with the planning application, in 2010. It confirmed at the planning inquiry in December 2011 that it accepted and agreed with his 2010 assessment. That work demonstrated that the site is not vulnerable to flooding within the TAN15 criteria. Nevertheless, the DAMs were not changed prior to the inquiry and the site remained within zone C2. The expert inspector accepted that the flood map and the DAM map for the site were in error at the second sentence of [112] of his report. Thus he treated the consequent conflict in terms of national and general development plan policy as one of form rather than substance. Finding that all other matters, including the flood consequences assessment were satisfactory, he recommended granting permission.
32. Yet Ms Ellis QC continued, the Minister failed to grapple with the agreed factual basis at the inquiry and in the inspector's report, that the maps were wrong and therefore the classification of the site as C2 was incorrect. In consequence he made what she characterised as a "terrible mistake", which played a decisive point in his conclusion that planning permission should not be granted. The correctness or otherwise of the maps was a logically prior question which had to be faced and dealt with so that planning policy could be properly and fairly applied: Tesco Stores Ltd v Dundee City Council [2012] UKSC 13; [2012] PTSR 983, [22], per Lord Reed. Answering the question on a proper legal basis was not a matter of planning judgment. There was something fundamentally wrong and there was a shared public interest in getting it right.
33. Paragraph [14] of the decision letter, quoted above, failed to engage with the evidence and failed to take account of the agreed evidence. The Minister hid behind the maps and equivocated about their accuracy. All this meant a reviewable mistake of fact giving rise to unfairness as recognised in: E v Secretary of State for the Home Department [2004] QB 1044. The Minister had looked down the wrong end of the telescope in proceeding on the basis that the site was in zone C2. That assumption pervaded the decision letter and led the Minister to conclude that policy GDC30 was against the development. If the Minister had started at the other end – the site was not in zone C2 – planning policy would have favoured it. The only recognition that the maps were wrong was in paragraph [30] of the decision letter. In referring to this as the claimant's "submission", and in its reliance on Natural Resources Wales not having revised the flood map, the decision letter avoided the agreed evidential position at the inquiry. That was irrational.
34. The reality was that in Mr Allison's 2006 email, and in its letter to the Council dated 4 November 2010, Natural Resources Wales had accepted Mr Wilkinson's evidence that the flood maps were unsound and that the site was not at risk of flooding. It had never resiled from that position, which was underlined when it did not send counsel to the inquiry. The key role of Natural Resources Wales was recognised in Planning Policy Wales and in the then Minister's clarification letter CL 09-06 of 2006, which was not even referred to in the decision letter. Moreover, in taking into account at [14] of the decision letter that the flood maps and DAMs had not changed in their most recent 2013 versions, the Minister had unlawfully taken into account new matters. The claimants had not been given a "fair crack of the whip": Castleford Homes v Secretary of State for the Environment, Transport and the Regions [2001] P & CR 470, [52], per Ouseley J. Specifically, this was in breach of rule 17 (5)(b) of the Town and County Planning (Inquiries Procedure Wales) Rules 2003, SI 2003, No 1266, ("the Rules") which governs procedure after the close of an inquiry. It provides, in particular, that if the Minister takes into consideration any new evidence or matter of fact (not being a matter of National Assembly policy) and is for that reason disposed to disagree with a recommendation made by the inspector, the applicant and council should be notified of the disagreement and reasons, and afforded an opportunity to make representations.
35. Ms Ellis QC then submitted that the Minister treated as irrelevant as a material consideration the evidence about the actual flood risk to the site, or failed to give adequate reasons as to why he rejected that evidence. At [112] of his report, the inspector properly reported that the site was not at risk of tidal flooding in either a 0.5% or a 0.1% flood event with a 50 year design life and sea level rises based on TAN15 criteria. (She also advanced this as a mistake of fact as to the baseline susceptibility of the site to flooding). Reasoning was also said to be lacking as to the Minister's approach to the flood consequence tests in TAN15. At paragraph [20] of the decision letter the Minister had said that he did not consider them relevant but he had then applied them. In Ms Ellis QC's submission, that was a flaw. TAN15 adopts a pragmatic approach in the application of the tests it contains. Yet the Minister had applied the development plan and national planning policies slavishly without regard to the underlying policy and the reality on the ground. Form was given precedence over substance and proportionality ignored. Proportionality is demanded since European law requires the precautionary principle to be applied in that way: R (on the application of Manchester Ship Co Ltd v Environment Agency 2012 EWHC 1643, [2013] JPL 515, [44] (on appeal on a different point at [2013] EWCA Civ 542). All this, and the fact that there was no reference to the 2006 clarification letter, meant that there had been an unlawful misapplication of policy and an irrational and unfair approach.
36. Ms Ellis QC took particular objection to the Minister's reliance on the three additional tests in Appendix 1.15 of TAN15 in paragraphs [22]-[23] of the decision letter, which he noted the inspector had not taken into account. The claimant's concern was not least because this tougher line involved an unheralded departure from the approach of Natural Resources Wales. It had indicated in its 4 November 2010 letter that climate change allowances needed only to be assessed on the relevant thresholds in Appendix A1.14, not A1.15. Natural Resources Wales' reasoning was that the climate change effects were uncertain. If the Minister intended to diverge from Natural Resources Wales on this point it was in fairness bound to give its reasons. Mr Wilkinson had taken into account the first of the four factors, maximum depth of flooding, set out in Appendix A1.15. Since that was lower than the threshold levels in Appendix A1.15, Mr Wilkinson's view was that it was superfluous to address the other three factors. Before me Mr Wilkinson submitted evidence where these other three factors – maximum rate of rise of flooding, maximum speed of inundation and maximum velocity of floodwaters – were worked into his analysis. The new evidence could have been raised earlier, Ms Ellis QC said, if the Welsh Minister had indicated that it was relevant. I do not propose to discuss the new evidence.

Discussion

37. It is trite law that the Minister had to have regard to the statutory development plan and had to determine the appeal in accordance with the development plan unless material consideration indicated otherwise: Town and Country Planning Act 1990, s. 70(2); Planning and Compulsory Purchase Act 2004, s. 38(6). On the DAM the site lies within zone C2, an area at risk of flooding where the statutory development plan, GDC30, provides that development will not be permitted, and where national planning policy TAN15, section 6, provides that development should not be permitted. The inspector in paragraph [111] therefore acknowledged there was a conflict with planning policy and identified as a main issue at the inquiry whether, given this conflict, there were material considerations to outweigh it. He held that there were and recommended in favour of granting planning permission. One of the material considerations, he said in paragraph [117], was the liability or otherwise of the site to flooding (which he discussed in paragraph [112]). In his decision letter not to grant planning permission the Minister agreed with the inspector that the proposed development was in conflict with planning policy but concluded that other material considerations did not outweigh that conflict. Provided he took into account all material considerations, and did not take into account any immaterial considerations, the weight to be attached to those considerations was a matter for him: Tesco Stores Ltd v Secretary of State for Environment [1995] 1 WLR 759, 780, per Lord Hoffmann. So in the absence of legal error the case is quite straightforward.
38. As I have said Ms Ellis QC advanced what she contended was the Minister's legal errors under various heads – material and vitiating error of fact; failure to take into account relevant considerations; misapplication of policy; lack of reasons; and breach of statutory provisions. Essentially these reduced to submissions about the Minister's "terrible mistake" in treating the site as within the extreme flood outline of the maps and thus within zone C2 of the DAM, contrary to the agreed position with Natural Resources Wales, and his failure otherwise to have proper regard to the flood risks to the site. There was the additional, albeit minor, issue of what was said to be a breach of rule 17 of the Rules in the reference to the 2013 versions of the flood map and the DAM.
39. Since I do not accept the premise of these submissions there is no need for me to engage in an elaborate analysis of how legally they should be characterised. First, it simply cannot be said that the Minister unlawfully failed to have regard to the uncontested evidence that the site had been incorrectly included within the extreme flood outline and zone C2. At paragraph [14] of the decision letter he expressly noted the submission made during the inquiry that the DAMs were incorrect. (Nothing turned on the use of the word "submission": that is the type of forensic approach to decision letters which the courts have deprecated: Clarke Homes Ltd v Secretary of State (1993) 66 P & CR 263, 271-2, per Sir Thomas Bingham MR). The remainder of paragraph [14] is an accurate statement about the maps and does not address their underlying accuracy. It points out that the most up-to-date version of the DAMs reflect the latest flood maps, and that Natural Resources Wales had not provided any information as to a significant change. By reference to paragraph [112] of his report, the claimants submitted that the inspector accepted that the maps were wrong. That is not stated expressly but is certainly a justifiable inference. For present purposes the important point is that at paragraph [26] the decision letter takes in paragraph [112] of the inspector's report.
40. Earlier in the judgment I described how, under both the UDP and national planning policy, residential development is not permitted in zone C2 of the DAMs. With zone C2 there is no need to refer to the flood risks dealt with in TAN15. If residential development is proposed for zone C1, however, the policies provide that in considering if it is to be permitted the criteria in Appendix 1 of TAN15 are to be satisfied, the onus being on the developer to show that. Before the inspector, both claimants had argued that the most important issues in terms of flood risk was the actual risk of flooding on the site. (As we saw Mr Wilkinson expended a great deal of effort on that; the Council said that that evidence should be given precedence). Thus the inspector devoted a large part of his discussion of this "main consideration" – whether there were material considerations outweighing the conflict with planning policy – to an analysis of actual flood risks at the site, including what TAN15 had to say about it. The Minister adopted precisely the same approach; he did not disagree with the inspector as to the facts about the risk of flooding. However, his judgment about the conclusions to be drawn was obviously different. As we have seen the inspector had concluded that there would be no unacceptable flood risk and that there would be tolerable conditions in a 0.1% probability event. The judgment of the Minister was that, even if the mitigation measures of raising ground levels were put in place, it had not been shown that there would not be an unacceptable risk of actual flooding.
41. I simply cannot understand Ms Ellis QC's submission that the Minister took a formal approach to planning policy, which he applied slavishly (putting to one side authority such as Hall v Aggregates (Thames Valley) v Secretary of State for the Environment [1986] 1 EGLR 194, that whether to a adopt a flexible or strict approach to the application of planning policy is a matter of planning judgment). It seems clear to me that the Minister went to the purposes behind the policy. Hence the reference to the precautionary approach of TAN15 in paragraph [19] of the decision letter. That precautionary approach, with its reference to the trauma, damage and disruption flooding can cause, is evident in section 2 of TAN15. It then leads to the overall principle stated there of avoiding development in areas where the consequences of flooding will be unacceptable. Section 3 of TAN15 reiterates the precautionary approach.
42. In my view, in assessing the actual risk of flooding, the Minister was plainly entitled to take into account the thresholds set out in Appendix A1.14 and A1.15. He noted that the parties and the inspector had looked to the question of whether there actually was an acceptable flood risk on the site and that they had used paragraphs A1.14 and A1.15 of TAN15 as an aid to assessing this. It will be recalled that Mr Wilkinson's evidence to the inspector was directed at demonstrating that the thresholds were met. In the passage from his additional note for the inspector, quoted above, he accepted the need for a robust assessment of actual flood risk, taking into account climate change and sea level rises when considering Appendix A1.15. Mr Wilkinson proposed to satisfy Appendix A1.14 by the implementation of mitigation measures in the form of raising the ground level of the site. Given that, a robust approach seems to be particularly important.
43. When Mr Wilkinson addressed the first threshold in Appendix A1.15 – depth of flood waters – he did so having taken into account climate change and sea level rises. He did not address the other three thresholds in Appendix A1.15. These are now said to be superfluous because Natural Resources Wales do not take into account climate change and sea level rises when considering Appendix A1.15. But that is not an answer when Mr Wilkinson has done so, and asserted that TAN15 is satisfied, albeit that until the hearing before me he had only addressed the first of the four thresholds in Appendix A1.15. I am still at a loss to understand why, if it was appropriate to look at the first threshold, the depth of a potential flood, the other three thresholds – the rate of rise of floodwaters, the maximum speed of inundation, and the maximum velocity of floodwaters – are not addressed. It seems to me that they are plainly relevant when assessing an actual flood risk. In my view, therefore, in light of the precautionary approach in planning policy, the Minister was entitled to adopt a robust approach. As part of that he was entitled to go beyond Appendix A1.14 to look at all four thresholds set out in Appendix A1.15 as an aid to assessing actual flood risk. When the onus is on Castletown I simply fail to understand how this constitutes unfairness. At the end of considering all these matters the Minister was entitled to conclude that he was not satisfied that there was no flood risk to the site.
44. That brings me to Natural Resources Wales. At the outset it is important to appreciate that Natural Resources Wales have never said expressly that the maps are incorrect. The email on 17 February 2006 was sent in relation to Mr Wilkinson's hydrological study and before the 2006 flood consequences assessment was forwarded. In the 2010 letter to the Council Natural Resources Wales certainly said that the conclusions of Mr Wilkinson's 2010 flood consequences assessment appeared reasonable and it had no adverse comments with regard to flood risk, but that the Council should liaise with other bodies regarding access (an aspect of Appendix A1.15). In January 2013 Natural Resources Wales said that updated hydrology would need to be run through the models, and that the flood consequences assessment then being commissioned by the Council would be used in updating the flood maps.
45. In the decision letter, the Minister took into account Natural Resources Wales' consideration of the proposed development (at paragraph [22]). He also noted that although it took into account climate change and sea level rises when considering Appendix A1.14 of TAN15, its policy was not to do so when considering Appendix A1.15 (at paragraph [17]). So he took into account these considerations but, as he was entitled to, took a different view. As for the Minister's failure to mention the 2006 clarification letter CL-09-06, which refers to the role of Natural Resources Wales in planning matters, that goes nowhere. Not only does a planning authority not need to cover every issue in its decision letter (Bolton MDC v Secretary of Stare for Environment ([1995] 71 P & CR 309, 314-5, per Lord Lloyd, with whom the others agreed), but on its face the clarification letter says nothing of relevance to the role of Natural Resources Wales in this case. Thus it cannot be said that the Minister failed to have regard to the uncontested evidence which was relied on to show that the site had been incorrectly included within the extreme flood outline or that he slavishly applied planning policy. In my view the Minister had regard to relevant considerations and reached a planning judgment that was properly open to him.
46. That leaves rule 17 and the Minister's reference to the latest flood map data and updated DAMs issued in 2013. I agree with Mr Moffett's submission that the notion that the Minister took into account new evidence in this respect, which was fundamental to the rejection of the inspector's recommendation, has an air of unreality about it. The purpose of r 17(5) is to ensure that a fair procedure is followed and that parties get a fair crack of the whip. In the present case there was no unfairness. It was public knowledge that the flood maps were updated on a quarterly basis, and it was also public knowledge that updates DAMs were published in early 2013. As far as the site was concerned, nothing had changed. The claimants are really submitting that they did not have the opportunity to make representations on the fact that nothing had changed. What new would they have said? What was said to be fresh evidence merely confirmed that the position was as it had been before the inspector. Accordingly, it was not the case that the Minister was disposed to disagree with the inspector for that reason. There was no breach of the Rules. Even if I had thought that there were, there was in my view no unfairness.

Conclusion

47. For these reasons the application is dismissed.