CLOSING STATEMENT ON BEHALF OF THE ACQUIRING AUTHORITY
Read full statement here
Introduction
- It is only a matter of time before Oxford suffers from major flooding on the scale of
that experienced in 1947.2 When this happens, over 1,600 properties in Oxford
will be internally flooded.3 Two of the main arterial routes into Oxford will be closed
and so will the railway. There will be disruption to power and services. Such an
event will destroy property and pose a risk to life. Such a flood could last for over
seven days.
- Even the comparatively modest flooding over the last two decades, and even this
year, has caused disruption for many and devastation for some. Some of those
directly affected by flooding have given evidence to the inquiry in support of the
scheme, in addition to those representing communities affected.4 The message
from these individuals is clear: they will never forget the trauma and fear that
flooding causes. The temporary disruption caused by the construction of the
scheme is demonstrably outweighed by the substantial benefits that it will deliver.5
The serious risk that flooding poses must be dealt with as soon as possible.6
- Even those who object to the scheme do not dispute the need for action to be taken
to alleviate the effects of flooding in Oxford.7 There is, therefore, a considerable
consensus about the need for the scheme. For the reasons that have been
explored in detail during the course of the inquiry and will be summarised in these
closing submissions, the Oxford Flood Alleviation Scheme is the best solution, and
the only scheme before this Inquiry capable of appropriately meeting this need.
Without this CPO, the scheme simply cannot be delivered. Indeed, there is no
scheme suggested to this Inquiry which could deliver a flood alleviation scheme
without the compulsory acquisition of land and rights of a similar extent to those
required for the Scheme itself.
- The remainder of these closing submissions are structured as follows:
- The need for the scheme;
- Scheme design;
- Benefits of the scheme;
- Commitment from scheme partners;
- Justification for the land take;
- Alternatives;
- Compliance with the adopted development plan for the area;
- Funding for construction and maintenance;
- Physical and legal impediments;
- CPO as a last resort and efforts to acquire by agreement;
- The CPO Guidance;
- Public sector equality duty;
- Human rights impacts;
- Compliance with section 19 of the Acquisition of Land Act 1981;
- Other matters;
- Conclusion.
The Scheme is needed now
- The Inspector and Secretary of State will need little convincing as to the urgency
for delivery of a flood alleviation scheme for Oxford. Oxford sits at the confluence
of seven rivers, which drain a predominantly rural catchment area of 3,000 square
- Downstream of Oxford, the floodplain significantly narrows to 300m wide,
increasing water levels upstream in flood conditions.8 Due to the in bank capacity
of the river Thames and secondary rivers, water overtops the riverbanks once flows
are greater than a 1 in 2 event (50% annual exceedance probability9).10 The River
Thames is slow to respond to rainfall, meaning that floods events are long in
duration, typically lasting over seven days.11
- A long history of development within the western floodplain means that it is heavily
populated.12 The constraining effect of the built environment means that the roads
and bridges that cross the current river channels do not have sufficient capacity to
pass flood flows, even for the smaller, more frequent flood events like those
experienced in recent years. This leads to flood waters backing-up and spilling
into vulnerable areas.13 At present, the standard of protection for properties and
infrastructure in the city varies but is as low as 1 in 5 (20% AEP) in places.14
- As explained in opening, Oxford has experienced flooding events in 2000, 2003,
2007, 2009, 2011,15 2012 and 2013/2014. It has since experienced flooding in
January 2024, during the adjournment of this Inquiry. On each occasion, properties
have been subject to internal flooding. Photographs from the 2003 floods show
the sheer extent of flooding.16
- Flooding of the scale experienced in 2007 is currently estimated to have a 1 in 10
year return period. During that flood event, residents in Botley and on Osney Island
8 Richard Harding’s Proof, page 13, para 2.17.
9 AEP
10 Richard Harding’s Proof, page 13, para 2.18.
11 Richard Harding’s Proof, page 14, para 2.19.
12 Thames Catchment Flood Risk Management Plan, pp.24 – 25 (CD2.6).
13 Richard Harding, Proof, page 14, para 2.19.
14 Richard Harding, Proof, page 14, para 2.21.
15 Oxford has reportedly experienced internal flooding in 2009 and 2011 but the Environment Agency
has been unable to verify figures. Statement of Case, page 5, para 2.9 (CD1.3).
16 Richard Harding, EiC, (Day 1) INQ/8a.
were evacuated; and two main arterial routes into Oxford were closed, in addition
to many other local roads.17 The mainline railway was closed for over five days.18
- Had the Scheme been in place, each of the eight flood events that have taken
place since 2000, including this year’s flooding, would have been avoided.19
- The flooding in recent years, whilst devastating for those affected, has been
relatively modest in scale. The last recorded major flood in Oxford was in 1947.
In the event of a flood of this magnitude, over 1,600 properties in Oxford would be
internally flooded, including 300 non-residential properties.20 Such a flood would
also cause major disruption to the road network, railway and utilities. As explained
by Richard Harding, “it’s a matter of ‘when’, not ‘if’” 21 such a catastrophe will occur
without a flood alleviation scheme.
- The extensive network of interconnected secondary watercourses in Oxford,22
most of which are in the western flood plain, means that implementing flood risk
measures to one area could leave properties and infrastructure at risk of flooding
from another watercourse and could exacerbate flooding in other areas.23 For this
reason, Oxford is treated as a single flood cell for the purposes of developing a
flood alleviation solution.24
17 Richard Harding, Proof, page 11, para 2.8.
18 Richard Harding, Proof, page 11, para 2.8.
19 Richard Harding, Proof, page 62, para 13.4.
20 Richard Harding, Proof, page 16, para 2.28. See Apx B to the Flood Risk Assessment for an
indication of how a major flood would affect Oxford (CD3.38a).
21 Richard Harding, EiC (Day 1).
22 See identification of the streams and rivers at CD2.3.
23 Richard Harding, Proof, page 14, para 2.20.
24 Richard Harding, Proof, page 14, para 2.20.
25 Richard Harding, Proof, page 14, para 2.20.
26 Richard Harding, Proof, Apx 6.
27 Richard Harding, Proof, Apx 7.
28 Gareth Simpson, Proof, page 9, para 4.1.
Action taken to date
- Oxford does not currently benefit from any formal flood defences.25 Flooding is
currently managed through the Thames Valley Local Resilience Forum Multi
Agency Flood Plan26 and the OCC Flood Plan.27 As explained by Mr Simpson, the
Environment Agency carries out maintenance activities under its statutory powers
on the principal watercourses in Oxford to help to reduce flood risk for low order
events28 and monitoring year round flow levels through the Environment Agency’s
telemetry system.29 Current maintenance activities include blockage removal,
vegetation management and targeted tree works.30
- The Environment Agency has already taken additional short-term action to alleviate
flooding in Oxford. This has included procuring temporary flood barriers following
the floods in 2007.31 These barriers were deployed during winter flooding in
2012/2013 and 2013/201432 at South Hinksey Village and Osney Island, and again
this month. New culverts were installed in 2014 at pinch points, including at Willow
Walk and at the Network Rail access track at Old Abingdon Road.33 These
measures comprise phase 1 of the three-stage strategy for managing flood risk in
Oxford, as explained further below.
- Whilst these measures have helped reduce the localised impact of flooding where
deployed, what has been done to date is simply not enough to address the risks of
flooding in Oxford, and comes at a significant resource cost each time a flood event
occurs.
29 Gareth Simpson, Proof, page 5, para 3.9.
30 Gareth Simpson, Proof, page 9, para 4.2.
31 Gareth Simpson, Proof, page 6, para 3.14.
32 Gareth Simpson, Proof, page 6, para 3.14.
33 Richard Harding, Proof, page 30, para 5.9(a).
34 Page 10, CD2.6.
35 CD5.10.
36 CD5.3.
37 Richard Harding, Proof, page 21, para 3.6(a).
38 Richard Harding, Proof, page 50, para 9.11.
Impact of climate change
- The climate emergency facing this country needs no introduction. As recognised
in the Thames Catchment Flood Management Plan, climate change is the major
cause of increased flood risk in the future.34
- In response to the Government’s UK climate change predictions published in
November 2018,35 the Environment Agency published a new guidance note in July
2020 on climate change allowances.36 The predicted uplifts for river flood flows for
the catchment area of the scheme are 11%, 13% and 30% for the 2020s, 2050s
and 2080s.37 The practical effect of this is that more properties will be at risk from
the same flood event than they would be today.38 Put another way, flood events
which would cause disruption and damage to homes and businesses will become
more frequent. As Phil Raynor explained39, when climate change effects are
considered a flood event which would have been a 1 in 100 year (1% AEP) event
in 2016 will be a 1 in 50 year (2% AEP) event in the 2020s, and a 1 in 20 year (5%
AEP) event in the 2080s. Thus he told the inquiry that there is no doubt that flooding
on a substantial scale of the likes of that experienced in Oxford in 1894, 1903 and
1947 will happen again, especially with the effects of climate change.40 None of
this evidence is questioned by the objectors.
39 Phil Raynor, EiC (Day 1); see also INQ/14 Slide 10
40 Phil Raynor, EiC (Day 1).
41 Richard Harding, Proof, page 17, para 3.2.
42 The 2010 version of the guidance is at CD5.7. The guidance was updated in March 2022 (CD5.8).
43 Richard Harding, Proof, page 18, para 3.3.
44 Richard Harding, Proof, page 19, para 3.4(b). Section 11.3.2, page 154 (CD5.6).
45 Richard Harding, Proof, page 19, para 3.4(b).
Scheme design
Key guidance
- In order for a proposal to secure public funding, HM Treasury requires that an
appraisal is carried out in order to determine the value that that proposal would
secure in accordance with the Green Book.41 As HM Treasury funds Flood and
Coastal Erosion Risk Management (‘FCERM’) schemes, a Green Book
assessment must be carried out in respect of such schemes. The requirements of
the Green Book therefore underpin the Flood and Coastal Erosion Risk
Management (‘FCERM’) Appraisal Guidance on evaluating investment in FCERM
schemes.42 All publicly funded flood defence strategies and projects must be
assessed against this guidance.43
- The FCERM Appraisal Guidance prescribes how a leading option is to be selected,
by identifying the option with the highest average benefit:cost ratio as the leading
option. Options are ranked in order of increasing benefits. Additional benefits of
the options are compared to the additional costs required to secure them, providing
an incremental benefit:cost ratio (‘iBCR’).44 ‘Do nothing’ and ‘do minimum’ options
are also included within the appraisal, in accordance with the Appraisal
Guidance.45 The standard appraisal period for flood defence strategies and
schemes is 100-years.46 This is the period that has been used in appraisal of the
scheme, although its benefits will extend beyond that period.
- It is notable that the Appraisal Guidance emphasises the need to adopt a
proportionate approach to appraisals.47 The 2010 version of the Appraisal
Guidance made clear that a project team should "avoid excessive data collection
or abortive works", which requires non-viable options to be identified efficiently.48
- Whilst a number of objectors49 have criticised the scheme selection process, it is
significant that none of those objectors suggest that the approach of applying the
Appraisal Guidance is wrong, or that there is some alternative basis for scheme
selection that should have been adopted. Indeed, the two hydrologists called as
expert witnesses for objectors agreed that the Appraisal Guidance was the correct
tool to use to select the scheme.50 It was also accepted that compliance with the
Appraisal Guidance is necessary to do so in order that any flood defence scheme
can be funded by Treasury.51 It is therefore beyond dispute that the scheme has
been selected through the application of the relevant guidance on flood risk
management measures: a point which underscores the compelling case for the
scheme and thus the CPO, and which undermines any suggestion that an
alternative should be preferred.
- Notwithstanding that agreed position between all the experts, there are various
suggestions from non-statutory objectors and indeed from the advocates for both
FHT/OFEG and OPT that alternatives should be preferred because the benefits of
those alternatives are not significantly lower than those of the scheme. This turns
the Appraisal Guidance on its head. It prescribes a process to optimise the use of
public money in flood relief schemes. It does not prescribe a separate series of
subjective judgements as to whether, for example, the additional benefits of the
selected options are a “tiny fraction”52 of the overall benefits.
The Appraisal Guidance is the correct guidance to decide the preferred option for flood alleviation
in Oxford.
46 Richard Harding, Proof, page 20, para 3.4(e).
47 Richard Harding, Proof, page 19, para 3.4(d).
48 Richard Harding, Proof, page 19, para 3.4(d).
49 Most significantly, OFEG/FHT and OPT.
50 Rhys Coombs, XX (Day 4). Clive Carpenter, XX (Day 8).
51 Agreed: Rhys Coombs, XX (Day 4).
52 OPT closing, 94. See also the suggestion at OPT closing 115 of considering "the extent of
incremental difference". This approach is not consistent with the Appraisal Guidance.
Overview of design development
- The Appraisal Guidance has not, however, been applied in isolation, but rather
following a long period of evolution of the scheme that was initiated following the
July 2007 floods. It has been subject to a thorough, detailed and ongoing process
of review and has been informed by flood risk modelling.
In summary:
- The Oxford Flood Risk Management Strategy (‘OFRMS’) was produced in
response to the 2007 floods. The strategy, which was approved in
September 2010, reviewed over 100 options or combinations of options.
The strategy recommended a three-phase approach to managing flood risk
in Oxford over the next 100 years.53 The first phase (Oxford Short Term
Measures) was completed in 2014 and involved localised river dredging,
vegetation clearance and culvert works.54 The second phase, which is now
this scheme, involves increasing the flow capacity of the river and floodplain
system through Oxford.55 The OFRMS did not at the time identify the
precise location or configuration of the conveyance. The third phase will
most likely involve upstream flood storage, which would be subject to a
separate appraisal if required at a later date to address the effects of climate
change.56
- Six technically viable options for the second phase identified in the OFRMS
were reviewed in October 2014. This took place following the winter
flooding in 2013/2014, which led to the formation of the Sponsoring Group.
In light of the flood events that had recently occurred, the review concluded
that the second phase was now both technically and economically viable.57
- The Strategic Outline Case was approved in June 2015. A long list of
fourteen viable conveyance options were reviewed, and the
recommendation reached was to pursue a new conveyance channel, in
53 Richard Harding, Proof, page 3, para 1.8.
54 Richard Harding, Proof, page 3, para 1.8.
55 Richard Harding, Proof, page 25, para 4.0(a).
56 Richard Harding, Proof, page 3, para 1.8.
57 Richard Harding, Proof, page 25, para 4.0(b) and page 35, para 7.6(a)-(c).
combination with the enlargement of existing channels in the western
floodplain. 58
- The Outline Business Case was approved in November 2017, which
reviewed options centred on a conveyance channel. Localised defences
were introduced to work in combination with the channel. Fourteen options
were subject to a multi-criteria analysis and economic assessment. An
economic appraisal of the options was carried out in accordance with the
FCERM Appraisal Guidance, which involved comparing each option’s iBCR.
The outcome of the appraisal favoured a medium conveyance channel with
localised defences.59 The alignment of the channel was determined through
detailed design undertaken as part of the Outline Business Case.60 This
process considered a number of options for the seven geographical areas
within the study area.61
- The Full Business Case, which is yet to be submitted to the Treasury, refines
the costs and benefits of ten options.62 The preferred option is the medium
conveyance channel with permanent localised defences as well as the
deployment of temporary defences.63 The Full Business Case will not be
submitted for approval until the necessary consents for the scheme have
been secured.
- In accordance with the FCERM Guidance,64 a proportionate approach has been
taken to the assessment of options that are not feasible, either due to technical,
economic or environmental reasons.65 It should be noted in this regard that the
objector’s alternatives, which are considered further below, are ones which are not
considered feasible.
58 Richard Harding, Proof, page 25, para 4.0(c).
59 Richard Harding, Proof, page 25, para 4.0(d).
60 Richard Harding, Proof, page 39, para 9.3.
61 Richard Harding, Proof, page 39, para 9.3(a).
62 These are set out at page 58, para 12.2 of Richard Harding’s Proof.
63 Richard Harding, Proof, page 26, para 4.0(e). This is explained further by Richard Harding in
section 12 of his Proof.
64 CD5.7.
65 Richard Harding, EiC (Day 1).
Role of engagement in design
- The scheme’s development has been informed by extensive consultation with key
stakeholders and the public over many years. A series of public consultation
events were held in summer 2015, followed by five public drop-in sessions held in
January to March 2016 as part of the Outline Business Case, which were attended
by nearly 900 people. An online public consultation was held between January
and March 2016.66 The feedback from stakeholders, the public and key
landowners formed part of the multi-criteria analysis, which identified a preferred
route in each geographical area.67 Downstream focus group sessions were held
in May 2016, followed by a series of pop up and drop-in events and meetings with
Parish Councils in 2016 to 2017.68 Throughout the development of the scheme,
the Environment Agency has engaged directly with community and residents
groups.69 In May 2021, whilst COVID-19 measures remained in place, the
Environment Agency conducted virtual engagement events and an online
feedback questionnaire.70
- The need to meet the scheme objectives, without increasing flood risk to others,
inevitably constrains the ability of the Environment Agency to accommodate every
change to the scheme sought by landowners. Wherever possible, however, views
of landowners and affected parties have been taken into account in the design of
the scheme. A clear example of this is in respect of the impacts on Hinksey
Meadow.71 Four alternative alignments were identified and presented to OPT. The
outcome of the engagement with OPT was that the present alignment was
considered to be the ‘least worst’ option.72 A further example is the design of the
main compound, which has been amended in direct response to concerns of
residents of South Hinksey village.73
- Whilst certain objectors,74 have sought to criticise the extent of engagement on the
design of the scheme,75 it is readily apparent that the scheme has been subject to
extensive engagement over a period of very many years. It is inherent in the
principle of consultation that it invites a range of views; it is inevitable that not all of
66 Statement of Community Involvement, section 3.5 (CD3.37).
67 Richard Harding, Proof, page 40, para 9.3(b).
68 Statement of Community Involvement, sections 3.8 – 3.12 (CD3.37).
69 Statement of Community Involvement, sections 3.13 (CD3.37).
70 Statement of Community Involvement, sections 3.14 (CD3.37).
71 Richard Harding, para 9.4(d).
72 Richard Harding, Proof, page 42, para 9.4(d); Richard Harding, EiC (Day 1).
73 Statement of Community Involvement, sections 7.12 (CD3.37).
74 In particular, Patricia Murphy on behalf of OFEG.
75 See Patricia Murphy, Proof, pages 3 – 4, paras 10 – 14.
the views expressed can be taken forward by the Environment Agency.76 The
criticisms about the engagement process are, in substance, merely expressions of
dissatisfaction about the extent to which particular representations have shaped
the development of the scheme.
- With regards to the specific objection advanced by OFEG, it is notable that the
group was only formed in November 2021, a matter of months before the
submission of the planning application and some six years after engagement on
the design of the scheme began.77 As accepted by Patricia Murphy, all of the
points now raised by OFEG are issues that were raised by consultees during the
engagement process and were therefore live issues for the Environment Agency
to consider during the design development. Indeed, the Environment Agency has
engaged directly with a number of individuals that are now prominent members of
OFEG, but were formerly part of other groups.78 The fact that the Environment
Agency does not agree with the proposals promoted by OFEG does not undermine
the adequacy of the engagement that has taken place. Engagement can be
adequate notwithstanding that the views of some consultees are not ultimately
accepted.79
76 Accepted by Patricia Murphy, XX (Day 7).
77 Confirmed by Patricia Murphy, XX (Day 7).
78 Such as Rod Chalk and Brian Durham. Patricia Murphy accepted in XX that these individuals, who are now part of OFEG, have been engaged with the scheme for a long period of time and prior to the formation of OFEG (Day 7).
79 Accepted by Patricia Murphy, XX (Day 7).
80 Phil Raynor EiC (Day 1). INQ/14.
81 Phil Raynor, Proof, page 5, para 4.1.
82 Phil Raynor, Proof, page 5, para 4.1.
83 Phil Raynor, Proof, page 5, para 4.2.
Role of hydraulic modelling in design
- The development of the scheme has been informed by two models; a fluvial model
and a groundwater model. Phil Raynor explained the evolution of both models in
his evidence.80
- The fluvial model was used to simulate the river flows and overland flood flow
mechanisms.81 It was used to represent the existing flooding mechanisms in
Oxford and test the proposed designs to ensure that the flood risk reduction
benefits were maximised.82 The fluvial model has also allowed a geomorphological
assessment of the impacts of the scheme to be carried out.83 This enables an
understanding of how the channel would behave in terms of erosion and deposition
of silt and gravels.84
- The groundwater model has been used to understand the impact of the scheme
on the groundwater flood risk.85 The groundwater model used outputs from the
fluvial model to simulate the changes that the scheme may have on groundwater
levels and flows across the Oxford area.86
- The fluvial model has been built to represent the channels in the Oxford area.87 It
covers approximately 19km of the River Thames and a much larger area than
Oxford. This ensures that local boundary condition uncertainties do not impact the
accuracy of the model results.88 The groundwater model covers a similar extent to
the fluvial model, which includes local environmentally sensitive sites.89
- Modelling has been used in the design of the scheme since the OFRMS. The
existing models were updated and improved at the Outline Business Case and
subsequently to create the detailed design model for the Full Business Case
stage.90 As such, the models have evolved over time based on information
gathered from surveys, both of the channels and structures on the floodplain, to
ensure that the physical representation of the current situation is as accurate as
possible.
- The in-flows to the fluvial model represent the hydrology of the catchment area.
The model has been updated on the basis of a detailed review of the historical
flood record from gauges within the scheme area.91 An annual maximum average
flow has been calculated for each gauge, which informs the flood frequency
curve.92 The modelling produces an estimated flood return period for each
catchment, which respond at different rates to each other in a flood event. The
variability of sub-catchment areas, reflecting the fact that water levels in sub-
catchment areas peak at different times, has been assessed.93 This has been
84 Phil Raynor, Proof, page 5, para 4.2.
85 Phil Raynor, Proof, page 5, para 4.3.
86 Phil Raynor, Proof, page 5, para 4.3.
87 Phil Raynor, EiC (Day 1). Page 1, INQ/14.
88 Phil Raynor, Proof, page 6, para 5.2.
89 Phil Raynor, Proof, page 6, para 5.4.
90 Phil Raynor, Proof, pages 9 – 10, para 7.4 – 7.5.
91 Phil Raynor, Proof, pages 12 – 13, para 8.4 – 8.6.
92 Phil Raynor, Proof, page 13, paras 8.6 – 8.7.
93 Phil Raynor, Proof, page 13, para 8.7.
subject to extensive sensitivity testing, which provides increased confidence in the
flood frequency analysis.94
- The model has been calibrated against recorded information from the July 2007
flood event.95 The model has been verified through the simulation of further
historical events, using the parameters developed through calibration.96 The model
was updated and improved in response to the calibration and verification work,
resulting in a level of accuracy of typically within 0.1m.97
- To ensure the accuracy of the groundwater model, it has been calibrated to actual
recorded groundwater levels observed at 20 locations during the 2007 flood
event.98 The calibration of the model was refined using observed data from bore
holes across the scheme area.99 Pump tests have been undertaken to understand
how permeable the ground strata are.
- Both models have been peer reviewed by external consultants on a number of
occasions.100 The review process concluded that there was no reason to doubt
the results given the quality of the modelling.101 Indeed, fluvial hydrologist and
hydrogeology experts instructed by both OFEG and OPT do not dispute the quality
and suitability of the modelling for optioneering, development and design of the
scheme.102
- In accordance with the latest climate change guidance, the 1% AEP (1 in 100 year
event) inflows used for the fluvial model are subject to an 11% uplift as baseline
for the 2020 epoch.103 For the epochs beyond this, the model adjusts further for
the effects of climate change. In practical terms, and as noted above, this means
94 Phil Raynor, Proof, pages 14 - 16, paras 8.9 – 8.12.
95 See Calibration Report, page 153 in Apx C to Flood Risk Assessment (CD3.38a). Phil Raynor,
Proof, page 20, para 9.4.
96 See Calibration Report, page 153 in Apx C to Flood Risk Assessment (CD3.38a). Phil Raynor,
Proof, page 20, para 9.4.
97 Phil Raynor, Proof, page 22, para 9.8.
98 Phil Raynor, Proof, page 24, para 9.15.
99 Phil Raynor, Proof, page 24, para 9.15.
100 Phil Raynor, Proof, page 34 ff., section 12.
101 See Appendix H of the 'Oxford Flood Alleviation Scheme Detailed Design Hydraulic Modelling
Report', page 117 in Appendix B of the FRA (CD 3.38a).
102 Rhys Coombs, XX (Day 4). Clive Carpenter, XX (Day 8).
103 Phil Raynor, Proof, page 37, para 13.3.
See full statement here https://www.hwa.uk.com/site/wp-content/uploads/2023/08/OFAS-EA-Closing-Submissions-rev-2.pdf