Developing a decision making task based on coastal management.
Generic title: How can the problems of coastal flooding be controlled effectively?
Key questions of specification:
2.1 What are the advantages and disadvantages of hard and soft engineering strategies used to
manage our coasts?
3.2 What is the most sustainable way to manage our coastline in the face of rising sea levels?
Contextual information for teachers:
Decision making exercise based on a Shoreline Management Plan – a summary for Cardiff to Newport
(Wentlooge or Wentloog) is available. A summary has been included below
The land around the Severn Estuary is low lying. Sea level rise or an increase in the amount of coastal
flooding could affect a large geographic area.
Sea level rise is thought to pose the greatest real risk and be the most important consideration in deciding
on the right policy option to manage coastal flooding and climate change. To work out which areas of the
estuary would be affected by sea level rise, the change in Mean High Water Springs (MHWS) is seen as
the most appropriate and has therefore been calculated to assist in policy making.
Mean High Water Springs (MHWS) is the average height that the tide reaches on a Spring Tide.
Spring Tides basically occur when there is a new moon or a full moon. Spring tides rise furthest up the
shore at high tide and go out furthest at low tide (i.e. maximum tidal range occurs). MHWS gives the
average highest level that the tides reach at high tide.
As sea level rises, MHWS will rise as well, meaning that the tide will reach further and further up the shore
profile and further and further in land, particularly where the land is low lying (as is found within this SMP2
area). Land which, over time, is affected by MHWS moving landwards becomes unusable without
intervention for many purposes – it cannot be used for housing, commercial development, farming, etc.
because it is regularly covered by the tide (approx. twice per month). Showing how MHWS changes over
time in the SMP2 area is, therefore, very useful for people that make decisions about planning and land
use because it will highlight areas that will become unusable. It is for this reason that this SMP2 has
introduced a valid variance to the Defra Procedural Guidance.
The UK Climate Impacts Programme scenarios (UKCIP02) suggest that by 2080 the sea level will rise by
between 20cm and 80cm in the South West and by about 40cm around Wales. These predictions have
recently been updated. The UK Climate Projections 2009 (UKCP09) estimate sea level rises between
37cm and 53cm in England and Wales.
Possible titles:
Are the Newport Levels worth saving from sea level rise? If so, what is the most sustainable way to do
this?
How and why should the shoreline at Wentlooge be managed in the future?
How can the problems of coastal flooding be controlled in the future on the Newport levels?
Teaching prior to the Research phase
Teach about the management of the coastline in England and/or Wales. Consider the benefits and
limitations of both hard and soft engineering techniques. Give students the opportunity to consider the
economic, social and environmental impacts (good and bad) of each of the following options:
 Do nothing
 Retreat the line
 Hold the line
 Advance the line
Use Hodder’s Option Topics book to practice a decision making exercise based on the Shoreline
Management Plan for Borth on the Ceredigion Coast (pages 6 – 10)
Student sheets for the research folder
The decision making task
< Put your chosen title here >
Your task: You have been asked to write a report for the local council. In it you should recommend a
future Shoreline Management Plan for the Wentloog Levels. Which of the following options will you
recommend?
 Do nothing
 Retreat the line
 Hold the line
 Advance the line
In your report you should:
 Describe the issue that faces people in this area;
 Consider various options that could be used to manage the coastline;
 Decide which option (or combination of options) you think should be used;
 Explain why you think your choice is best.
Remember, you report will be marked using a mark scheme which will give good marks if you:
 Show that you understand why coasts are protected;
 Explain the limitations and benefits of various strategies for coastal defence;
 Consider why people have different views on this issue and recognise bias;
 Analyse evidence (eg from maps, photos, tables of data);
 Use a range of skills;
 Use evidence to support your conclusions.
Student instructions
There are two phases to your task:
Phase 1 The Research phase
You have 5 hours (this is a maximum – you can have less)
You should spend about half of this time doing some basic processing of the data in your file.
You are allowed to:
 Make notes
 Draw graphs
 Draw sketch maps and other types of map
 Label photos
 Plan the structure of your report
 Ask your teacher questions
You could spend the other half of your time doing some research into:
 Land uses at Wentlloog
 Strategies for coastal defence – the benefits and limitations of each type
 Opinions about whether coastal defences are needed
You will be able to collaborate with each other.
You must not take any work home.
Keep all your work in a folder.
Phase 2 The Writing phase
You have 8 hours (this is a maximum – you can have less)
You must work independently.
You must hand in your work to the teacher at the end of each session.
Plan your time carefully when you are in this phase.
You will not be allowed to add anything to your folder or use the internet in this phase.
Evidence that you may find useful
Figure 1 The value of agricultural land
Agricultural land classification grade Value (£ per hectare)
1
6,290
2
6,290
3
5,050
4
4,500
5
4,500
Source: Middlesex University, Flood Hazard Research Centre
Figure 2 The cost of coastal defences
Defence type
Cost to maintain
(£ per km per year)
Hard defences eg seawalls, rock
10,000
revetments
Earth embankments, groynes etc
10,000
Beach management,
20,000
replacement of sand, shingle etc
Source: Shoreline Management Plan Guidance Volume 2
Cost to build
(£ millions per km)
Replacement
period (years)
2.7
100
0.6
50
5.1
30
Figure 3 How rising sea levels affect flat coastlines with and without a seawall
Useful websites
http://www.geograph.org.uk/
This site has lots of photos of landscapes in England and Wales, including many of the area between
Newport and Cardiff. Each photo has a reference so you can locate it on an Ordnance Survey map. You
can search the site using place names – try Wentloog or Wentlooge. Alternatively, use OS grid
references. For example ST3083 is a grid square which has a reen (or drainage ditch) running through
it. Another interesting square is ST2981 which shows sea defences. Start from one of these squares and
use the pan buttons to explore the landscape.
You could:
 Match photos to an OS map so that you can describe the landscape of the area
 Annotate the features of selected photos
 Use the photos to describe land use and estimate agricultural land values (using figure 1)
http://www.environment-agency.gov.uk/homeandleisure/floods/default.aspx
Follow the link to <flood map>. Use the search engine on this page to find maps of the coastline
between Cardiff and Newport and discover whether or not they are at risk of floods.
The post code CF10 2TN will get you to one interesting area. From here you can use the pan buttons to
explore the rest of the coast.
http://www.severnestuary.net/secg/docs/Issues%20and%20Objectives%20leaflet_Wentlooge.pdf
This website summarises the Shoreline Management Plan for the area.
http://www.caldandwentidb.gov.uk/
This is the website of the Caldicot and Wentlooge Internal Drainage Board. The Board is responsible for
the Water Level Management of the Gwent Levels, an area of land between Chepstow and Cardiff.
http://www.cardiff.gov.uk/objview.asp?object_id=3599
A fact sheet published by Cardiff Council
http://www.wwf.org.uk/filelibrary/pdf/mu52.pdf
A fact sheet published by WWF. Abbots Hall Farm, Essex, has experienced managed retreat. A hole
was made in a coastal embankment and some parts of the farm are now flooded at high tide. This will
eventually recreate a salt marsh which will be a natural defence against rising sea levels.
Some opinions to consider
Caldicot and Wentlooge Internal Drainage Board
Extensive areas, including major centres of population and industry, are at risk of being flooded from the
sea, rivers and smaller watercourses. Major flood events have been recorded through history and it is an
exceptional year when no significant property flooding takes place. The land use of those areas within
the Drainage Board Districts is totally dependent upon complex systems for Flood Defence and Land
Drainage. Without such systems the development of homes and factories, the provision of public
services and productive use of farmland, would not be possible.
RSPB spokesperson
The Gwent and Wenloog levels are areas of reclaimed land taken from the sea many centuries ago. It is
drained by a network of reens (ditches and drains) that are now valuable for wildlife. Because of this, the
whole area is a massive Site of Special Scientific Interest and an excellent place for bird watching.
Spokesperson for Cardiff Council
The Wentloog levels may not seem to be very valuable or important to some people. However, the
levels are a beautiful area of countryside that are right on the doorstep of Cardiff. They provide a
wonderful wild and peaceful place for people to walk or cycle.
Local resident
My family has farmed here for generations. I love this area and its wildlife. This is where I want my
children and grandchildren to grow up.
Resident in Newport
I don’t see the point of spending money protecting this land. Hundreds of years ago it was salt marsh – it
might as well go back to being salt marsh again. They would be better off spending the money they save
on local schools or hospitals!