|
 Frequently
Asked Questions
prepared by the Environment Agency
What
is the Environment Agency's role in managing coastal erosion and flooding?
Since
1st April 2008 the Environment Agency
(the EA), having managed UK riverine flood
risk for many years, has
also
been responsible for the management of all
flood and erosion risk on the English coast.
This
means the EA:
-
Takes
the lead in managing all sea flooding risk in England.
-
Funds
and oversees coastal erosion works undertaken by local authorities.
-
Ensures that proper and sustainable long-term Shoreline Management Plans
are in place for the English coastline.
-
Works
with local authorities to ensure that the resulting flood and coastal
erosion works are properly planned, prioritised, procured, delivered and
maintained to get maximum value for taxpayers' money.
-
Ensures that third party
defences
are sustainable.
What is the
Local Authority 's role?
The role
of the Local Authority is very important. Local Authority officers
have very good knowledge & experience of the coast, and strong links with
the community. The EA need to work very closely with Local
Authorities to deliver a Strategic Overview for sea flooding an coastal
erosion risk management.
Why
is the coast changing?
Coastal
change is a natural, ongoing process that has always happened.
As sea
water meets cliffs and shores, it causes sediment or rocks to be broken
down and washed out to sea. In some instances, this material may be moved
to a different part of the coast and deposited in large quantities,
causing 'accretion' - the opposite of erosion, where shorelines may
advance or build up with sediment over time. In fact, the sand and
shingle that makes our beaches is a product of erosion, and to remain in
place they need a continual supply of material.
Erosion
can happen under any conditions, but its rate tends to increase when waves
are powerful and water levels are
 high
- for instance during storms or in high winds.
How do
waves cause erosion?
Waves
cause erosion to happen in four main ways:
-
Waves
bring with them particles of rocks and sand that grind the cliff down.
-
The
constant force of water against the shore wears it away.
-
The
action of powerful waves causes rocks and pebbles from the shore to
smash into each other and break up.
-
Acids
in the sea also slowly dissolve certain types of rocks.
How
does erosion affect our coast?
The way
erosion changes different parts of our coast depends largely on the type
of rock - in other words, its geology.
Erosion
of coasts with hard rocks tends to be slower, and can form dramatic rock
formations over time, including tunnels, bridges, columns or pillars such
as at Lulworth Cove in Dorset.
Where
coastal geology is formed out of sedimentary deposits, such as on the soft
cliffs around parts of the east coast, erosion can pose more of a risk for
human settlements. Sedimentary rocks, such as sandstone and chalk,
naturally erode more easily than hard rocks, so the coast recedes at a
faster rate.
Coastal
erosion and coastal flooding are often linked. One may lead to another,
especially where an eroding shoreline
separates
the sea from flat, low-lying land.
How has our shoreline
changed over the years?
Shorelines constantly change due to waves and tides. The amount of
physical change depends on many things, and happens over timescales from
seconds to centuries.
The
changing coastline has also been influenced by people’s actions throughout
the years, particularly in attempts to stop the effect of erosion or
flooding. In some cases, this has taken place without an appreciation of
the effect these actions could have on other places up and down the coast.
How fast is the coast changing now?
The
tremendous diversity of our coast means that erosion rates vary
significantly from area to area. Some parts of the coast are eroding
faster than others.
To put
things into context, across England and Wales, about 28 per cent of our
coastline is subject to erosion of more than 10 centimetres per year, but
rates vary according to location, sometimes reaching an average of as much
as 1.8 metres per year.
In
reality, coastal erosion is not always gradual, and can occur through
events such as landslips where many metres of land may be lost once every
five or ten years. Rates of erosion are expected to increase by the
end of this century because of increasing storms and rising sea levels,
brought about by climate change.
Predicting these rates as accurately as possible is, of course, extremely
important - not only for the people living in our
coastal
communities, but also for the EA in our work managing the coast.
How is coastal erosion predicted?
It's
crucial that we understand and can predict large-scale, longer-term
coastal changes, so that we can manage the risk to coastal settlements and
the natural environment more effectively.
To
predict erosion, we use a range of advanced monitoring techniques to
assess its causes and ongoing impact. This includes using aerial
photographs, maps and surveys of coastal processes, which can then be
analysed by teams of scientists. Records of historical rates of erosion
on the coast also inform our predictions of how the coast might evolve in
the future.
We can
then use this detailed information about our coast to:
-
make predictions about the rate and impact of erosion;
-
assess existing coastal management methods and how cost-effective they
will remain over time;
-
make informed decisions about
future management, to ensure we tackle coastal erosion issues where
the risk is greatest.
We are
using the most up-to-date data on climate change, advanced modelling
techniques and the best local survey information available to map coastal
erosion predictions across England. These maps will be easily accessible
to everyone from the
EA's website, so that all who live at, work on and
manage the coast are better able to decide how to
approach
coastal change in their local area.
What is dredging and what effect does it have on erosion?
Dredging
is the removal of sand and gravel from the coastline or seabed:
-
to keep waterways
navigable
-
to produce material
for construction projects
-
to replace the
materials lost from beaches as a result of erosion
It is
sometimes claimed that dredging causes coastal erosion, or makes it worse,
as it has in the past.
Various
studies have recently been carried out to assess whether dredging makes
surrounding areas more prone to erosion or not. Research results, such as
those from the Southern North Sea Sediment Transport Study, shows
that because dredging is now strictly controlled and carefully managed in
UK waters, it no longer has an impact on coastal erosion.
A
licence is required for dredging. Thorough assessments are carried out to
ensure dredging will not have a negative impact on the coastline or the
marine environment before a licence is granted.
Marine
dredging licences are administered by the Marine
Management Organisation.
What can be done to reduce the risk of coastal erosion?
There
are many measures we can take to defend our coastline against erosion.
This is often a combination of various defence structures and natural
features. These measures can reduce the effects of coastal erosion upon
communities and the natural environment.
Coastal
management methods fall into two main categories:
-
Hard engineering
- man-made barriers such as sea walls and groynes, which reduced the
impact of waves on the coast
-
Soft engineering
- techniques such as beach replenishment and saltmarsh creation which
use natural materials, features and processes to absorb wave impact.
Many
successful coastal management methods combine hard and soft techniques.
In each case the effects upon coastal processes and the natural
environment are fully explored before management decisions are made.
What is being done to protect coastal wildlife and habitats?
The EA have
a legal duty to protect and enhance the natural environment through our
operations. The management of important nature conservation sites that
are at risk of coastal erosion or flooding is considered in
Coastal Habitat Management Plans (CHaMPs).
Relocating natural habitats
Some
forms of sea defence can have a negative impact on the coastal
environment. 'Coastal squeeze' occurs when natural habitats become caught
between sea defences and the sea. This can result in
the loss of
salt marshes, mudflats and beaches.
As these are important feeding grounds for birds and other wildlife,
their loss can have serious environmental consequences.
Inter-tidal habitats are also important for local commercial fisheries, as
they provide important nursery areas.
Where
natural habitats are unavoidably lost, we seek to replace them elsewhere
through regional 'habitat creation programmes'.
Working with others
We use a
wealth of expertise to carefully assess environmental impact. We work at a
local and national level with Natural England, the government agency
responsible for promoting the conservation of England's wildlife and
natural features. We also work closely with the many organisations that
make up the UK Biodiversity Partnership, who are
actively
involved in conservation work.
Where / what do you choose to defend, and why?
The EA
uses public money as effectively as possibly to reduce the risk to coastal
communities, their property, infrastructure and the natural environment.
Decisions on where to defend are based on risk assessment using a
transparent, auditable and understandable process.
Factors we consider include:
-
Number of households at risk.
-
Number of deprived households at risk.
-
Impact of our actions on agricultural land and the farming community.
-
Impact of our actions on the environment and wildlife.
-
Whether erosion affects local community infrastructure and transport.
-
Cost
of building and maintenance.
There
are four possible outcomes:
-
Hold
the existing defence line - maintain existing coastal defence.
-
Advance the existing defence line - new defences on seaward side.
-
Managed re-alignment - shoreline adjusts position in a controlled way.
-
No
active intervention - no investment in coastal defence.
Coastal
defences often protect against both coastal flooding and erosion. Inland
flooding is also affected by how we manage coastal defences. Funding for
coastal and flood defence is therefore linked. In each case, a set of
agreed indicators called
'outcome measures'
are employed to measure how effectively economic, social and environmental
needs
are met.
How is flood and coastal risk management funded?
In
2009-2010, the Environment Agency will spend £700 million managing flood
and coastal erosion risk across the UK. This budget has more than doubled
from 10 years ago, and is set to increase by an estimated £100 million in
2010- 2011.
Despite
this large commitment, the scale of coastal erosion means we must
prioritise projects to ensure we achieve the best possible results.
Realistically, it is not possible to justify defending all locations to
the same standard or in some cases at all.
How coastal change affects you
Coastal
change can affect people in both positive and negative ways. Eroding
coasts can place houses, businesses and farmland at risk, yet others may
benefit from sediment moving along the shoreline and keeping natural
defences such as beaches and marshes healthy.
The risk
from erosion can bring problems for home and land owners relating to
insurance, property values and planning permission. Although insurance
may be provided against sea flooding, there is no insurance against
coastal erosion.
In some
locations it is not possible or appropriate to defend against erosion or
maintain existing defences. Where this
is
the case, together with local authorities, we will work closely with
communities to help them adapt to the changes.
How
policy is changing
Anticipating and responding to these problems is the subject of new policy
being developed by the Department for Environment, Food and Rural Affairs
(Defra).
The EA
are currently supporting the development of new proposals by Defra on how
communities can receive practical support to help them adapt to coastal
change.
The
Department for Communities and Local Government (DCLG) is also developing
new planning guidance on future development at the coast.
These
proposals are open to
public consultation
and we encourage you to have your
say. Find out more by visiting the links below:
The
first Shoreline Management Plans (SMP1s)
The
first SMPs were produced in the mid 1990s. Each length of shoreline is
currently managed in a particular way, according to the policies set out
in them, but meantime there have been several major studies including:
All
these studies have provided new information, and in light of this the
current shoreline management policies may no longer be practical or
acceptable in the long term. For example:
-
predications of sea
level rise due to climate change have increased dramatically since the
first round of SMPs, and need to be incorporated into the second
generation;
-
current defences may
have a limited life and improvements may not be economically, socially,
technically or environmentally practical;
-
changes in the
shoreline may result in new approaches being necessary to manage future
risks.
The
second generation of Shoreline Management Plans (SMP2s)
The
second generation of Shoreline Management Plans (SMP2s) are currently in
production, covering the entire 6000 kilometres of coast in England and
Wales.
Current
coastal management objectives are often widely accepted and embedded in
local planning policy. Therefore, wholesale changes to existing flood and
erosion defence management practices may not always be appropriate in the
very short term, and communities, businesses and wildlife habitats all
need time to adjust.
Consequently, the SMP2s will provide a ‘route map’ for local authorities
and other decision makers to move from the present situation towards
meeting our future needs, and will identify the most sustainable
approaches to managing the risks to the coast in the short term (0-20
years), medium term (20-50 years) and long term (50-100 years).
Within
these timeframes, the SMP2s will also include an action plan that
prioritises what work is needed to manage coastal processes into the
future, and where it will happen. This in turn will form the basis for
deciding and putting in place specific flood and erosion risk management
schemes, coastal erosion monitoring and further research on how we can
best adapt to change.
|
