Download Special Focus Investigation – Flood

Flood Investigation Report
Special Focus Investigation –
Flood implications for MOD
locations
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EXECUTIVE SUMMARY
0.1
The frequency and level of flooding is increasing due the impact of climate change, and
the risk associated with flooding is also increasing due to the increased value of land
and buildings in vulnerable areas. As a consequence the MOD will be at increased risk
from the effects of flooding. Certain locations will be at higher risk than others.
•
•
•
•
Climate change in the UK is likely to be associated with an increased risk of severe
flooding in low-lying and coastal areas and the return period of severe flooding
events is likely to be significantly reduced.
Fluvial flooding and raised groundwater levels are also likely to cause more flooding
events as a consequence of climate change.
Poor surface water drainage, particularly in built areas, will contribute to the extent of
inland flooding.
Flooding from overflowing sewers is also a concern, particularly for its implications
on staff and local communities’ health and well-being.
0.2
The results of a study that cross references MOD site locations with the Environment
Agency’s flood risk areas are presented here, with a discussion of additional flood risk
factors. This work illustrates the issue of flood for MOD locations and draws attention to
the requirement for a more structured approach to managing flood risk.
0.3
Implications for the MOD
•
•
•
•
•
•
•
•
•
0.4
Loss of training areas / training capacity
Public interest issues relating to military capability
Damage and loss of infrastructure
Health risks and Loss of life - flood deaths are primarily associated with flash floods,
however drownings in rivers in the estate is also of concern for the MOD. Risk of
death is also apparent from electrocution or carbon monoxide poisoning during flood
clear up stages. Health risks from contamination of flood water (stored chemicals,
munitions, oil, diesel, pesticides, sewage /effluent, etc.)
Contaminated land - release of contaminants from flooded land
Degradation of designated areas (biodiversity, cultural heritage)
Estate restrictions on transferring MOD activities to areas where they have not
previously been conducted
Inconvenience / drain on investment
Interruptions to power supplies
Recommended MOD Responses
Emergency plans
Review and strengthen MOD Emergency plans and preparedness to mitigate the effects
of floods.
Risk Assessments
Implement detailed risk assessments of the likely effects of a major flood of MOD lowlying areas.
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Staff skills
Estates staff need to be trained with the appropriate skills to undertake and advise on
these assessments.
Future Military needs
Further research into MOD locations and military needs and the employment of coastal
engineering for coastal defences in association with the appropriate OGDs is required.
The results from these investigations should be considered in all future site development
and investment decisions.
Information systems
Extended use of Geographical Information Systems to take full account of flood risk
factors should be made available in order to support flood risk assessments and
investment planning.
Wider effects
The wider consequences of development need to be fully accounted for, such as
increased runoff from areas of hard standing and development in the floodplain (less
land available for infiltration by rainwater) or coastal erosion resulting from hard
engineering.
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Contents
Page
1
Introduction
1
2
Aim
2
3
Scope
2
4
Flood Zone Information
3
5
Method
4
6
Results
5
List of Figures:
Figure A: Environment Agency Summary Map of Flood Probability
in England and Wales
Figure B: Map showing the spread and location of all MOD sites in
Northern England and Scotland (sites shown as red areas).
Figure C: Map showing the spread and location of all MOD sites in
Wales, Southern and Central England (sites shown as red areas).
Figure D: Map of MOD sites, with corresponding flood risk areas
highlighted in blue.
Figure E: Example map of a geoprocessed area demonstrating
flood zones at Shoeburyness.
Figure F: Example map of a geoprocessed area demonstrating
flood zones at the Wash Ranges.
Figure G: Example map of a geoprocessed area demonstrating
flood zones at Hythe and Lydd Ranges.
Figure H: DTE SE region showing Hythe and Lydd Ranges and
Cinque Ports Training Areas
Figure I: London
Figure J: Pendine
Figure K: Portsmouth
Figure L: Shoeburyness and Colchester Ranges
Figure M: The Wash Ranges
Figure N: SW Region - the Somerset Levels
Figure O: Cape Wrath
Figure P: Lossiemouth and Kinloss
Figure Q: Precipitation (% change) Annual and seasonal means
Figure R: Groundwater flood Hazard
7
Conclusions and Recommendations
8
Explanation of Flood Risk Factors
9
Biodiversity and Habitat Implications
25
Appendix 1
Defence Intranet News article 28/06/2007 Military teams assist flood relief effort
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SPECIAL FOCUS INVESTIGATION – FLOOD IMPLICATIONS FOR MOD LOCATIONS
1. INTRODUCTION
1.1
Climate change in the UK is expected to result in more frequent, high intensity
rainfall and periods of long-duration rainfall of the type responsible for the 2000 and
2007 floods, climate factors will also compound the rate and extent of coastal
change. Climate change will therefore have a significant impact on flooding. The
MOD estate will be exposed to greater risk as a consequence of climate change,
and these flood risks will be particularly prevalent in certain locations.
1.2
To provide an estate that is fit for purpose a wide variety of training media and
environments are required. The combination of infrastructure in association with
training areas means that many existing training facilities could not be replicated in
alternative locations. In these circumstances it is particularly important to be aware
of increased exposure to flood risk.
1.3
The UK defence estate is located across many sites and locations. A large number
of it’s assets are along and adjacent to the coast, in England and Wales alone this
amounts to a total coastal frontage of 558 km (347 miles) and 84 sites.
1.4
Many sites, both inland and coastal, are vulnerable to flooding. The effects of onsite or even flooding near to sites will be to cause disruption to site operations,
increase costs in relation to estate condition and repairs, release previously stable
contaminants and pose risks to health and safety. If this vulnerability is assessed
the risk of disruption and additional investment requirements can be minimised, and
issues of longer term viability of the site can be addressed in estate development
planning.
1.5
The Defence Estates Framework Statement on adaptation to Climate Change aims
to ensure that the risks and potential opportunities to the defence estate posed by
climate change are assessed and managed. The specific central government driver
in this objective is to ‘identify opportunities to site new developments in areas that
are less vulnerable to climate change impacts , and/or build resilience to climate
change into new developments an major refurbishment projects’ (Framework for
Sustainable Development on the Government Estate, Target G1B).
1.6
To begin to identify areas at particular likelihood of experiencing a flood event a
mapping exercise has been conducted that overlays the MOD estate with the
Environment Agency Flood Map data. This provides a rough indicator of areas that
are at risk of coastal or fluvial flooding.
1.7
Flood events are determined by a complicated series of interrelationships between a
number of flood risk factors. Flood events may arise from a number of sources,
including coastal erosion, storm and sea level rise, fluvial, groundwater and sewage.
Climate change will affect the level at which influencing forces are applied and the
characteristics of the land, coast or management activities will affect the localised
response. Additional details of flood risk factors and the influence of climate change
is described later in the text. It should be noted that where these factors apply the
risk of flooding could be significantly higher than indicated when looking at the EA
data alone.
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Storms
Physical
Land Use and
Geography Management
Geomorphology
& Topography
Wind Speed
and Direction
Hills / valleys
Precipitation
(intensity and
duration)
Rivers & other
Groundwater
levels
Geology
water bodies
Beaches
Coastal cliffs and
Physical
changes in soil
permeability
slopes
Coastal Waves
Tidal flats and
Tides
marshes
Coastal Storm
Surges
Estuaries
Dunes
Barriers and spits
Land Use
Structures
Building use / occupancy
Transport systems
Impermeable hard
standing
Undermining
Surface Eroding Activities
Destabilising Activities
Drainage burden &
capacity
River channel training
Introduction or removal of
stabilising vegetation
Coastal Defence
Structures / Management
Measures
Sea walls
Shore-parallel structures
Groynes
Detached breakwaters
Beach Recharging &
recycling
Managed realignment
Dredging
Addition of beach material
Reclamation
Estuarine modifications
Flood vulnerability
Climate change & flood factors
Forcing
Factors
Table 1: Climate change and Flood Factors
2. AIM
2.1
To conduct an investigation on the changes in flood risk associated with MOD
locations in England and Wales as a consequence of climate change.
3. SCOPE
3.1
This paper addresses the vulnerability and likelihood of flooding, using EA Flood
Zones and descriptions of additional factors including the effects of climate change.
The EA terminology for Flood Zones uses the term ‘risk’ as an indication of
probability of occurrence, therefore where risk is used in this report it is only used to
signify likelihood, rather than the full consequences of a flood event.
3.2
Risk is usually defined as a combination of the probability and the consequence of
an outcome, where consequence relates to the significance of the assets that may
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be affected. The significance of MOD’s assets is addressed through long term
planning and evaluation of estates requirements, for example, the Defence Estates
Development Plan (DEDP) and therefore is not within the scope of this report.
3.3
An investigation was conducted using the Environment Agency (EA) floodmaps, for
which DE hold a license to use, overlaid with MOD sites in England and Wales. At
the outset of this work the Scottish Environmental Protection Agency (SEPA) had
not produced and equivalent data set for Scotland, and there are no flood maps
available in this format for Northern Ireland. Since this work began SEPA have
produced a flood map database and dialogue has commenced between DE
Environmental Support Team (EST) Estate Information Team (EIT) on licensing
costs.
3.4
In addition to these maps, a text account is given, indicating how the flood probability
will be exacerbated as a result of climate change.
3.5
Some areas of the overseas estate, particularly those in low lying and coastal
regions, will be at significantly greater risk of flooding as a consequence of climate
change. This has not been included within the scope of this report.
4.
FLOOD ZONE INFORMATION
4.1
The Environment Agency (EA) is the lead authority on flood risk information in
England and Wales. The EA collect data about rivers and coasts to model how
floods could occur and map those areas that have been affected, or could be
affected in the future. The flood map is designed to raise awareness of the
likelihood of flooding and encourage appropriate action in areas that are prone to
flooding.
4.2
The EA Flood Map shows areas across England and Wales that could be affected
by flooding from rivers or the sea. It provides data on flood risk based on annual
probabilities of flooding. The Flood Map shows the flooding that would occur without
the presence of flood defences. The Flood Map also contains information about
defences and the areas that benefit from them, but these are not factored into the
Flood Zones data.
4.3
These maps are produced using topography data and information on river flows, sea
level and wave data. This means they provide a picture of the flood risk at the
current time and do not predict the impact of climate change. What they do indicate
is, given the changing influence of sea level rise, wave action, precipitation and
subsequent influences on coastal morphology and land form, areas that will
increasingly be at risk as the impacts of climate change take effect. This scenario
therefore provides an estimate of potential hazard mapping at a coarse level.
4.4
Flood Zones represent the natural flow routes, without the presence of flood
defences. The Flood Zones, therefore, may show an area at risk of flooding which
is different from that which would occur in a flood event if all flood defences perform
as they are designed, or defences are at risk of failure, or flow routes are
obstructed, or defences are breached.
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4.5
It is therefore appropriate that more detailed flood risk assessments (FRAs) are
considered for sites within Flood Zone 2.
4.6
Flood Map is used, under license with the EA, by the DE Estate Information Team.
The probability of flooding
4.7
The probability or likelihood of flooding is described as the chance that a location will
flood in any one year. If a location has a 1.3% chance of flooding each year, it can
be expressed as having a 1 in 75 chance of flooding in that location in any year.
However, this doesn’t mean that if a location floods one year, it will definitely not
flood for the next 74 years. The lower the percentage then the less chance there is
of flooding in any one year; the higher the percentage then the more chance there is
of flooding in any one year.
Zone
River
Sea
Flood type
1
Extreme
event
Chance of
happening in any
year
0.1 % (1 in 1000) or
greater
2
Moderate to
significant
1 % (1 in 100) or
greater
1
Extreme
event
0.1 % (1 in 1000) or
greater
2
Moderate
0.5 % (1 in 200) or
to significant greater
Survey data
used
Not in the
equation
Topography
Ground
surface
flows
existing
flood
defences
Sea level
and wave
data
Predicted
erosion
rates or
sea level
rise
existing
defences
Table 2: The flood map zones
5.
METHOD
5.1
The DE Estate Information Team used EA flood mapping data to identify which MOD
sites in England and Wales corresponded with areas identified by the EA as at risk
of flooding. The EA flood map for England and Wales is presented in Figure of
flooding in any one year.
5.2
Areas of land under MOD ownership are listed individually on the Defence Property
Gazetteer (DPG) as parcels. There is no clear definition for a MOD ‘site’, however
an area that is generally referred to as a site will be comprised of a number of
parcels. In order to produce statistics for this study, the parcels in a particular area
were ‘grouped’ together, hence the term ‘Group statistics’ used in the information
box accompanying maps E to G.
5.3
Using an information systems process called ‘geoprocessing’ the floodzone data
was ‘cookie cut’ against the DPG parcels to produce a dataset called
floodzones_MOD showing floodzone data that corresponded with MOD sites in
England and Wales. This data set is represented pictorially in Figure D. Limits in
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memory size were encountered during this work, therefore a new process available
on an upgraded next version of GIS software (ArcGIS 9.1) was pioneered which
enabled partitioning of the data on the fly during geoprocessing. The resulting data
partitions were then combined at the end to produce the required dataset.
5.4
The floodzone data in its raw form combines type (fluvial and sea) and risk (0.1 %,
0.5% and 1.0%) resulting in polygon areas that legitimately overlap. To remove
these overlapping areas the data was ‘mosaiced’ or ‘jigsawed’ so that each
combination of risk/type was unitised, therefore preventing incorrect duplication of
statistical output (a useful resource for any future site specific studies). The resulting
dataset is called floodzones_MOD_Union.
5.5
The coastline data was similarly produced using geoprocessing tools to ‘cut’ the high
water mark (HWM) (extracted from OS Landline data) with the DPG parcels. The
resulting linear dataset was then spatially joined to the original floodzone data,
resulting in it taking on the attributes of floodtype/risk depending on where the two
datasets were coincident. This gives information relating to length of MOD coastline
at risk of flooding and whether this flooding is attributable to sea, river or both, and
the level of risk from either.
5.6
This data is now available to be called upon to produce a variety of statistical,
mapped and graphical output, for any site in England and Wales, for example the
proportion of site at risk which can further be broken into floodzone/risk percentages,
total no. of sites at risk and percentage of total area of MOD sites at risk.
6.
RESULTS
6.1
GIS information available as a result of this study:
•
Identification of MOD sites in England and Wales that correspond with EA areas at
risk of flooding (the floodzones_MOD data set, held by the Estate Information
Team)
•
Maps to illustrate the risk at each site identified, as illustrated in Figures E to P
(available from the Estate Information Team on request).
•
Length of MOD coastline at risk of flooding and whether this flooding is attributable
to sea, river or both, and the level of risk from either
•
Statistical and graphical output for any site:
the proportion of site at risk which can further be broken into floodzone/risk
percentages
total number and identity of the sites at risk
percentage of total area of MOD sites at risk
Maps available as a result of this study
6.2
The results from the study are presented in graphical format in the following section.
For individual site use, copies can be requested at higher resolution from the DE
Operations South Estate Information Team at Westdown. Figures E to P are
illustrative of the type and detail generated as a result of the geoprocessing.
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Although not presented here, equivalent maps are available for all sites that
correspond with the flood zones.
Figure A: Environment Agency Summary Map of Flood Probability in England and
Wales
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Figure B: Map showing the spread and location of all MOD sites in Northern
England and Scotland (sites shown as red areas).
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Figure C: Map showing the spread and location of all MOD sites in Wales, Southern and Central England (sites shown as
red areas).
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Figure D: Map of MOD sites, with corresponding flood risk areas highlighted in
blue.
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Figure E: Example map of a geoprocessed area demonstrating flood zones at Shoeburyness.
6.3
The map shows the flood risk area (shown in blue), extending beyond the boundary of the MOD site (shown in pink). The
extent of peripheral flood risk and therefore the management response for the local area will have implications for on-going
MOD land use. The defence Property Gazetteer parcels for Shoeburyness already extend below the high water mark,
therefore the statistics for this group of parcels indicate that only 26% of this site would be affected. This is because the other
74% is regularly fully inundated.
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Figure F: Example map of a geoprocessed area demonstrating flood zones at the Wash Ranges.
6.4
These ranges occupy a narrow strip in an area of extremely high flood probability. They are also significant areas for nature
conservation, and sea level changes or flood events will have an associated impact on MOD’s legal obligations for biodiversity.
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Figure G: Example map of a geoprocessed area demonstrating flood zones at Hythe and Lydd Ranges.
6.5
The extent of floodzone at Hythe and Lydd ranges and the adjacent area of Romney marsh is the subject of an investigation
regarding realignment and flood defences which has been reported in the Defence Training Estate South East Military Needs
Paper (DTE SE MNP).
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REGIONAL PERSPECTIVES
6.6
This series of maps was generated to illustrate the widespread regional effects, both in
terms of immediate disruption as a result of flood events, but also to long term implications
to MOD activities.
Figure H: DTE SE region showing Hythe and Lydd Ranges and Cinque Ports Training
Areas
6.7
The DTE SE is the principal area for operational training. The range complexes comprise
the most extensive collection of urban training facilities in Europe and extremely varied
terrain. This makes the region unique in its training provision.
6.8
The area is demonstrably under threat from the risk of flooding and has been traditionally
been protected by a shingle bar that was regularly replenished. The Environment Agency
(EA) published a consultation document reviewing the coastal strategy in the South East in
2002, which considered ending the replenishment strategy and realigning the coastal
defences to the rear of the training area in order to protect Romney Marsh. These
recommendations were partly a result of the EA classifying the land as under low value
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agricultural use. This was challenged by a MOD economic valuation and the area is now
considered to be worth approximately £200m.
6.9
To explore options, it has been investigated whether an area of equivalent size (13,700ha)
would be available elsewhere on the UK mainland. The results have shown that, capital
costs and compulsory purchase issues aside, this size of space cannot be replicated in
another part of the UK, simply because an area the size required to translocate these
facilities, without constraints (designations / National Parks, urban or EA flood zone areas)
is not available.
6.10 However, it must be acknowledged that the inevitable effects of sea level rise and coastal
morphology mean that the sea is encroaching. These facilities are in the national interest
however if the overriding environmental conditions will put them untenable risk and sea
defences are not available the view that their situation cannot be altered is unsustainable.
Figure I: London
6.11 The MOD owns a number of properties in London, which are of high strategic, political or
financial value. London as a region is particularly vulnerable to the effects of climate
change from thermal heat islands effects and flood risk.
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6.12 Tide levels are steadily increasing owing to a combination of factors. These include higher
mean sea levels, greater storms, increasing tide amplitude, the tilting of the British Isles
(with the south eastern corner tipping downwards) and the settlement of London on its bed
of clay. As a result, tide levels are rising in the Thames Estuary relative to the land by about
60cm per century. Surge tides are a particular threat and occur when a trough of low
pressure moves across the Atlantic towards the British Isles.
6.13 The EA predict that a severe flood in London could paralyse the central part of the London
Underground, cause damage to fresh water and sewer systems and disrupt power, gas,
telephone and vital data services. It could take months to get London functioning again.
The financial cost of a major flood could be enormous, possibly topping £30,000m without
counting the cost in human suffering and potential loss of life.
6.14 MOD needs to assess the long term viability of retaining its assets and activities in this
region against how much its outcomes will be impacted on by prolonged flood risk or
events.
Figure J: Pendine
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Figure K: Portsmouth
Figure L: Shoeburyness and Colchester Ranges
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Figure M: The Wash Ranges
Figure N: SW Region - the Somerset Levels
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6.15 Figures J to N illustrate the extent of regional implications surrounding MOD sites. Whilst
the direct impact on MOD areas is not as pronounce in Figure N, the effect on the SW
region of this sort of flood event would be to isolate the region by cutting off motorway and
rail connections, therefore implications away from the site of flooding must also be
considered.
6.16 In extreme events the military are also called in to assist flood relief efforts, Appendix 1
details the military flood response aid in June 2007, which also acknowledges that
Normandy Barracks didn't escape the rising waters, with many soldiers having to spend
time baling out MOD property.
Potential areas requiring further investigation – Scotland and Northern Ireland
6.17 At the time of this study the Scottish Environment Protection Agency (SEPA) had not
published a Scottish equivalent to the EA flood maps, however this is now available. Figure
O, below, illustrates the location of Cape Wrath, which is identified as at risk of flooding from
the sea across its entire coastline
Figure O: Cape Wrath
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Figure P: Lossiemouth and Kinloss
6.18 Lossiemouth and Kinloss are both identified by SEPA as being at risk of flooding from the
sea across their coastline, with Kinloss also subject to potential fluvial flood risk on its
southern boundary.
6.19 These views are illustrative, an equivalent exercise would need to be conducted for
Scotland and Northern Ireland in order to systematically identify which sites correspond with
areas of risk.
Precipitation and Groundwater
6.20 Other sources of flooding include precipitation and groundwater. The surface of the water
table fluctuates seasonally in response to rainfall and over the longer term, levels will vary in
response to abstraction, changes in land use and climate change. Groundwater responds
slowly compared with rivers so floods can last for weeks or months, and whilst the area of
flood potential coincides strongly with the areas at risk in the east from fluvial and coastal
flooding, this risk exists in addition.
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6.21 Areas prone to changes in precipitation and groundwater flooding as a consequence of
climate change are reproduced below with permission from the British Geological Survey
and the UKCIP02 Climate Scenarios.
6.22 More detailed spatial information will be available in the UKCIP08 predictive information,
which will be available in 2008 and the British Geological Survey are able to provide
targeted geological information if requested.
Figure Q:
Precipitation (% change)
Annual and seasonal means
Figure R:
Groundwater flood Hazard
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7.
CONCLUSIONS AND RECOMMENDATIONS
7.1
Flooding is a natural process that can happen suddenly, and climate change can
significantly increase flood risk, both in the UK and globally.
•
Sea level rise is expected to result in predominantly eroding coastlines around the UK.
This, therefore, will impact on the land area and function of the MOD’s coastal sites.
•
Fluvial flooding will impact on stability and availability of MOD land to meet it’s intended
purpose
•
The issue of flooding is also interlinked with other spatially relevant climate impacts
affecting MOD locations.
7.2
The costs and protecting our assets and future investment will rise therefore minimising the
risk through design and preparation are key to an effective response. Whilst the effects are
a long-term, the issue requires immediate and ongoing management responses to these
challenges in order to provide long-term solutions.
7.3
An effectively adapted MOD should be able to:
•
•
•
•
•
Set an example
Lead / adapt Government
Utilise / Contribute to research and understanding
Provide protection against the danger
Seize the opportunity / manage the risk
Recommendations
Emergency plans
7.4
Review and strengthen MOD Emergency plans and preparedness to mitigate the effects of
floods. This should include off as well as on site issues for example, impacts on transport
and the identification of locations that are vulnerable to interruptions in strategic links and
alternative/diversionary routes are required.
7.5
Address an estate wide policy on managed realignment.
Awareness on how to interact with stakeholders on managed realignment would assist site
staff to ensue consistency of management is applied when these issues arise at site level.
Currently site responses are managed in an ad hoc manner.
Risk Assessments
7.6
Implement detailed risk assessments of the likely effects of a major flood of MOD low-lying
areas. Sites that coincide with flood map data are recommended to undertake a Flood Risk
Assessment, for the purposes of awareness and risk management, therefore the
assessments take place more frequently than when planning is required for new
developments.
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7.7
The Defence Estates Development Plan (DEDP) to ensure these factors are considered at
the appropriate time.
Staff skills
7.8
Estates staff need to be trained with the appropriate skills to undertake and advise on these
assessments and give suitable advice on the flood planning guidance.
7.9
Flood risk should be considered at all stages of the planning and development process in order
to reduce future damage to property and loss of life. This is the underpinning principle of the
Government’s Planning Policy Guidance 25 on Development and Flood Risk (PPG25). It is also
recommended that consideration of flood risk should take place as matter of course on MOD
sites in order to understand viability and inform long term investment decisions.
7.10 Provide an estate role for expert in flood risk management to:
•
•
•
•
•
•
Update on flood management policy in line with planning requirements and legislation
Advise on the practical implementation of PPS25 1
Long-term, sustainable approaches towards flood management
Ensure that the impact of land use on catchment flood management is minimised
Oversee the effective implementation of SUDS
Advise on effective methods for flood recovery
PPG 25 Development and Flood Risk
PPG25 sets out the Government’s policy on the role of land-use planning in reducing flooding
and the damage which floods cause.
The EA Flood Zones have been produced to enable planning authorities to apply the sequential
test for development proposals and prevent inappropriate development in areas at risk from
flooding.
MOD developments are categorised as water compatible, however, despite this classification it
is essential that flood risk on the estate is properly taken into account in order to reduce the risk
of flooding and the damage which floods cause.
7.11 Additional staffing would also be recommended to provide the information and data
management to support site requirements.
Future Military needs
7.12 Further research into MOD locations and military needs and the employment of coastal
engineering for coastal defences in association with the appropriate OGDs is required. The
results from these investigations should be considered in all future site development and
investment decisions.
Information systems
1
Plus: Making Space for Water, the Water Frameworks Directive, the Marine Bill, technologies and
methods for coastal zone risk management and monitoring, environmental and wildlife considerations in
design solutions, the impact of climate change and erosion.
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7.13 Extended use of Geographical Information Systems to take full account of flood risk factors
should be made available in order to support flood risk assessments and investment
planning.
•
Improve GIS information to show assets (assets currently only available on a database,
which does not allow a visual representation alongside other spatially based risks, i.e.
exactly where a building is positioned), and separate these out by value and TLB.
•
Computer memory size. The floodzone dataset is very large, which gave rise to computer
memory capacity problems when geoprocessing. To overcome this, the data was split
then reunited. This approach was more complicated, unstable and still very memory
intensive. Improved memory facilities would be advantageous to facilitate further work in
this area.
•
Use of other data / sources of information and costs. The EA data is used under licence,
but further information is being produced (for example, by SEPA, or DoE Environment and
Heritage Service Northern Ireland, British Geological Service, Association of British
Insurers) that if accessed, would be of value to MOD sites.
Wider effects
7.14 The wider consequences of development need to be fully accounted for, such as increased
runoff from areas of hard standing and development in the floodplain (less land available for
infiltration by rainwater) or coastal erosion resulting from hard engineering.
7.15 Safeguarding. The EA are developing a Water Resources Strategy for England and Wales
that intends to protect and restore wetlands. Wetlands assist in reducing flooding, diffuse
pollution and also provide habitats for rare species. Restoration of wetlands adjacent to
MOD sites would provide a means of managing our statutory biodiversity obligations (see
Section 9) as well as a means to offset run-off from areas of hard standing, however this
needs to be carefully weighed up with the implications for safeguarding, particularly in
encouraging wildlife in the proximity to airfields.
7.16 Overseas: Some areas of the overseas estate, particularly those in low lying and coastal
regions, will be at significantly greater risk of flooding as a consequence of climate change.
This has not been included within the scope of this report.
7.17 Critical infrastructure, for example ports and dockyards.
7.18 Water supply. In addition to flood concerns, the pressures on water systems are growing,
with increasing new development and more use of water. Climate change will have a major
impact on river flows, yields and groundwater resources which will add to these pressures
and the MOD will need to think differently and act now for its water resource planning. The
influence that land management has on the management of water resources and water
quality is therefore strongly linked to the flood issue.
7.19 Contaminated land and potential liabilities for re released contamination.
Recommended further investigations
7.20 Follow up to flood study. E.g. Site flood risk assessments.
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•
Extend phase 1 flood study to all UK MOD sites
Phase 2 – conduct detailed site pilot studies.
Phase 3, use the findings from the detailed site pilot studies to develop and implement a
plan for Flood Risk Assessment for all sites (needs definition).
Investigate overseas estate flood risk in relation to climate change.
•
7.21 The Research recommendations for the production of specific technical guidance on flood
resilient building techniques and the impact of flooding on the value property.
8.
EXPLANATION OF FLOOD RISK FACTORS
8.1
Factors that influence flooding:
•
•
•
•
•
•
•
Fluvial condition
Groundwater
Geology
Development (particularly roof areas and hard standing)
Drainage systems
Precipitation
Coastal change
Precipitation
8.2
Climate change predictions suggest there is potential for heavy winter precipitation to
become more frequent.
8.3
This would increase cliff and slope instability, increase winter flooding, could affect
vegetation patterns, which in turn affect stability, and would increase river flows and
sediment input.
8.4
Predicted drier summers would also be likely to result in flash flooding and rapid run off
when summer precipitation does occur.
Coastal change
8.5
The coast is a highly dynamic environment with continual changes in energy conditions
affecting erosion, sediment transport and deposition processes. The effects of the last
glaciation resulted in sediment deposits at the coastline which built up beaches of sand and
gravel. Since that time the sediment resource on many coasts has reduced, and this
problem is exacerbated at some locations due to sea defences. The accelerated rate of
change of sea level rise will have a further destabilising effect on coastal systems.
8.6
Sea level rise, storm intensity and surge height will increase as a result of climate change.
This will have an effect on the forcing factors (waves, tides, storm surges and wind) that
drive coastal change.
8.7
Coastal change that affects MOD sites principally arises from loss of land due to erosion
and coastline retreat. This will occur in the following conditions:
•
Where erosion exceeds accretion
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•
•
•
land subsidence (e.g. the tipping effect in the South East due to isostatic movement)
Sea level rise (caused by climate change from increased volume of water through
thermal expansion and melting ice).
Inundation of low-lying areas (e.g. tidal flooding as a result of breached sea defences or
natural barriers such as dune complexes). This can affect particularly large areas in flat
low-lying counties such as Norfolk, Suffolk and Lincolnshire.
Sea Level Rise
8.8
The UK Climate Impacts Programme (UKCIP) has established future climate scenarios for
the UK based on different global emissions scenarios. Since figures were produced in 2002
global emissions have continued to rise, so the UKCIP 2002 estimates for future sea level
rise presented below are based on the high emissions scenario.
Region
Net Sea-level Change 2080s (mm)
NE Scotland
SE Scotland
NE England
Yorkshire
East Midlands
Eastern England
London
SE England
SW England
Wales
Northern Ireland
NW England
610
600
660
750
800
820
860
790
760
710
690
670
Return Periods
8.9
Sea level rise will also cause a reduction in return periods; this means an increase in the
likelihood of flooding. An area that presently experiences minor sea flooding only once in
100 years is expected to experience this level of flooding more frequently in the future. The
level of sea flooding is also expected to become more severe (e.g. a floodwater depth of
100mm experienced once in 100 years in future, rather than a floodwater depth of 50mm
presently experienced once in 100 years).
8.10 Reduction in return periods 1: 100 yr event could change to a 1:7 year event – change in
class of flood.
Coastal forms relevant to MOD properties
8.11 Estuaries
Estuaries have generally been modified as a result of reclamation, training of river channels,
associated dredging. These impact on the estuary as well as adjacent shoreline. There is
often a significant difference in level between the land projected by the defences and nearby
salt marsh or mudflat due to dewatering and compaction following the reclamation. This
means that these reclaimed areas are very vulnerable to sea level rise, should defences
start to fail.
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8.12 Cuspate forelands (nesses)
Nesses are low coastal forms, which are common on the east of England (e.g Orfordness,
Suffolk, Shoeburyness, Essex). These features are sensitive to climate change and a
typical natural response is to migrate landwards. However in many locations the landward
migration is constrained by defences and under continued sea level rise there will be
coastal squeeze. Erosion or submergences may a result.
8.13 Tidal flats and marshes
The vegetation on saltmarshes trap sediments, creating a dynamic sediment redistributions
system. They disperse wave and tidal energy and are therefore important for reducing the
likelihood of flooding to low lying hinterland.
8.14 Saltmarshes are very sensitive to sea level rise and their survival depends upon sufficient
sediment and the space for saltmarsh to migrate landwards. This needs to be considered at
MOD coastal sites that are adjacent to saltmarsh, as hard protection of infrastructure
developments will result in coastal squeeze, and therefore reduce the potential of the
saltmarsh to manage flood risk.
Coastal Defence and Managed Realignment
8.15 Managed realignment is the deliberate, controlled action of retreating inland from the
existing line of sea defence.
8.16 Climate change and sea level rise means that defending coastlines is becoming more costly
and technically difficult. The increasing cost of maintenance means that existing defences
may be abandoned in areas with low population or fewer tangible assets. This approach
has been implemented in some former reclaimed, low lying areas of the Wash and Essex
estuaries.
8.17 Natural England, the Environment Agency and Defra are beginning to favour this approach
in preference to engineered sea defences in some areas and this will impact on MOD where
this strategy is being implemented adjacent to MOD coastal sites, for example Hythe and
Lydd.
9.
BIODIVERSITY AND HABITAT IMPLICATIONS
9.1
The European Birds and Habitats Directives and associated domestic legislation 2 have
implications for flood management as a consequence of coastal squeeze. Therefore the
planning of flood risk management and coastal protection must be consistent with the
requirements of these Directives and associated legislation.
9.2
Flood risk and coastal erosion management measures have an enormous effect on wetland
and coastal environments and their conservation interest. Habitat losses are due to a
combination of flood risk management and sea level rise.
9.3
The SD implications for any changes must be assessed in accordance with MOD policy, for
example the Appropriate Assessment of changes to a European designated habitat (see the
Sustainability and Environmental Appraisal Tools Handbook), in order to determine whether
2
Directive 79/409/EEC The conservation of wild birds and Directive 92/43/EC The conservation of natural
habitats and of wild flora and fauna, and the Conservation (Natural Habitats, &c.) Regulations 1994
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the activity may proceed and recommendations on any measures or conditions that may be
required.
9.4
Plans and projects at estuarine and coastal locations that are suffering a loss of intertidal
habitats due to sea level rise may only proceed if they will not adversely affect the integrity
of a European site (meaning there is no reasonable scientific doubt as to the absence of
such effects). To determine this, analysis of wave reflection, wider hydro-geomorphological
effects and any other relevant factors have to be taken into account, all of which are likely to
be difficult to distinguish from the impacts of sea level rise. Where it is proposed that the
line of defence is maintained in the face of sea level rise, it is unlikely that there will not be a
ignificant effect.
9.5
Alternatively plans or projects may proceed if there are no alternative solutions and it is
necessary for imperative reasons of overriding public interest, and any necessary
compensatory measures to protect the coherence of Natura 2000 are secured.
Compensatory measures
9.6
In order to help conserve sites currently subject to coastal squeeze and to avoid delays in
the implementation of justified flood management works, operating authorities are
encouraged to develop a strategic approach to the planning and delivery of any habitat
creation measures that they anticipate will be required before undertaking or seeking
consent for plans or projects. Wherever possible, Shoreline Management Plans, Catchment
Flood Management Plans and flood management strategies should be used to help
anticipate habitat creation requirements and opportunities. This approach should provide
the necessary business case, strategic framework and rationale for undertaking habitat
creation as part of compensatory measures and allow any synergies with sustainable
coastal management to be realised.
9.7
Intertidal habitat loss is mainly occurring in the south and east of the country, between the
Humber and Severn, therefore Defra 3 recommend that the preferred areas for intertidal
habitat creation will also be in those locations and preferably associated with the Natura
2000 sites where habitat is being lost due to coastal squeeze.
9.8
MOD sites will therefore be affected by Natural England and the Environment Agency’s
work to identify opportunities for habitat creation, particularly through the development of
Shoreline Management Plans, Catchment Flood Management Plans and flood management
strategies.
3
Department for Environment Food and Rural Affairs
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Avoiding deterioration of European sites
Appropriate steps must be taken to avoid flood management structures or activities causing the
deterioration of natural habitats, or the habitats of protected species, within European sites or the
disturbance of species for which the site has been designated that could be significant in relation
to the objectives of the Habitats Directive. This is required by Article 6(2) of the Directive. In
relation to marine/intertidal areas, any authority conducting operations is required to exercise their
functions relevant to marine conservation so as to secure compliance with the requirements of the
Habitats Directive14. The nature of the steps taken to meet these requirements will depend on
what is necessary and appropriate to avoid detrimental effects on European sites. English Nature
has agreed to work with operating authorities to help identify where flood and coastal
management work (including managed realignment) is needed to avoid the deterioration of natural
habitats in European sites.
Article 3 of the Wild Birds Directive
Article 3 of the Wild Birds Directive requires Member States to take measures “to preserve,
maintain or re-establish a sufficient diversity and area of habitats for all the species of birds
referred to in Article 1” of the Directive. This obligation should not be confused with the
requirements under Article 6 of the Habitats Directive, which are directly linked to the Natura 2000
network. However, any compensatory measures secured to protect coherence of Natura 2000 and
steps taken to avoid the deterioration European sites under Article 6 of the Habitats Directive
might be expected to contribute to meeting obligations under Article 3.
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APPENDIX 1
DEFENCE INTRANET - Military teams assist flood relief effort
28/06/2007
A number of Army and Royal Air Force personnel
along with an RAF Chinook heavy lift helicopter have
been helping the emergency services with the flood
relief effort in the north of England.
In Bentley, just north of Doncaster, the Environment
Agency identified a weak point on the River Don. An
18 Squadron Chinook helicopter, from RAF Odiham
in Hampshire, was immediately called in to help lift
around 150 tonnes of aggregate near the village of
Almholme in a bid to reinforce and support the banks
of the River Don.
Throughout the evening of Wednesday 27 June 2007
the helicopter made several trips, carrying the bags
as an under-slung load. They continued with the
lifting this morning, Thursday 28 June 2007.
Flight Lieutenant Stu Gerrard, 28, Officer
Commanding the Mobile Air Operations team at RAF
Benson, has been helping to coordinate the RAF
assistance in Doncaster:
"We've been supporting the Environment Agency's
operation," explained Flt Lt Gerrard. "What we're
doing is lifting around 150 bags of aggregate to try
and reinforce the river and prevent it from overflowing.
An 18 Squadron Chinook helicopter, from
RAF Odiham in Hampshire, helps to lift
around 150 tonnes of aggregate near the
village of Almholme in a bid to reinforce
and support the banks of the River Don
[Picture: MOD]
"We've been working with numerous different organisations, including the police and the fire
service. We've taken the lead on how to get the bags where they need to get to. The danger of
lifting these loads all makes for a challenging and tricky operation.
"This is unique in terms of the specific role we're carrying out here but in terms of flying and
preparing loads, it's what we train for. It's more the equipment we're using and the multi agency
working that is different to what we're used to. But it is good to know our unique skills are being
used."
This week's floods, which were most severe in Yorkshire, Lincolnshire and the Midlands, have
already claimed four lives. On Monday 25 June 2007 RAF Search and Rescue helicopters
worked through the evening to rescue more than 100 people stranded in Hull and Sheffield.
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Flt Lt Gerrard has followed the events of the last few
days with interest, particularly the assistance
provided by his RAF search and rescue colleagues:
"We had no idea we would get called in," he said. "I
obviously knew that if there was a real need then we
might get called upon to help because we hold a very
short notice standby to do this sort of thing, 365 days
a year, so we are always available if needed."
Sergeant Paul Waterhouse, from 18 Squadron at
RAF Odiham, has been helping to liaise with the
numerous agencies involved in the flood relief effort
to make it all possible:
Help is at hand: An elderly man is lifted to
safety [Picture: MOD]
"Everything has gone very smoothly so far," he said.
"It's been diffcult getting everything together, the logistics side of it in particular. but it's great for
us to be involved and it's good for the civilian population that we can carry out this role when
required."
Meanwhile four assault boats and their four-man Army crews deployed from 38 Engineer
Regiment in Ripon to an electricity substation at Thorpe Marsh near Doncaster. They used their
boats to cross the flood water surrounding the substation and then reinforced the flood protection
with sandbags on key buildings.
They have also been transporting members of the South Yorkshire Fire and Rescue Services,
with their pumping equipment, and National Grid personnel as well as shuttling the 45-gallon
drums of diesel that fuel the substation's emergency generators:
"Only two boats have been on the water at a time but
everyone has got their feet wet during this task today,"
explained Captain John Kirkman, who headed the team.
"The substation is surrounded by a floodwater lake and we
have placed about 150 sandbags to help protect certain parts.
We have been pleased to be able to support the Fire and
Rescue Service and National Grid at this time."
Personnel from The Defence School of Transport (DST) at
Normandy Barracks, Leconfield in East Yorkshire have also
been in the thick of the flood relief effort throughout the
Humber Area, mainly in and around Hull. Filling and
distributing sandbags is just one of the many tasks they have
undertaken.
Soldiers from The Defence School of
Transport help with the flood relief
effort [Picture: MOD]
The soldiers have also helped deliver hot food to the civilian
police as well helping to rescue those who were trapped in their homes and, in one instance,
helping to rescue disabled pensioners from sheltered accommodation in Cottingham, near Hull.
Normandy Barracks itself didn't escape the rising waters, with many soldiers having to spend time
baling ourselves out.
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DST spokesman Captain Terry O'Hagan said:
"I'm very proud of the work that our chaps did. They just got on with it, cheerfully and
uncomplainingly. The civilian population were most appreciative and provided us with copious
amounts of tea, sticky buns, sandwiches and soup – which was very touching considering their
circumstances."
So far the DST soldiers have filled 9,000 sandbags for local authorities, filled and delivered a
further 2,400 throughout the area, ground loaded 1,000 more and have 600 sandbags loaded on
trucks ready to move at short notice should the situation worsen.
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