What are the options for coastal cities
Flooding is a growing problem for
the UK’s coastal towns and cities as rising sea levels and man-made
constraints conspire to increase the risk of inundation.
edie (January 14, 2010) - A joint report from the
Institute of Civil Engineers (ICE) and RIBA spin-off building
future attempts to spark a wider debate by using military metaphor
to look at the three broad options - retreat, defend or
attack.
Pulling back from the coastline and estuaries to avoid catastrophe
is one option, says the report, making a distinction between a
managed retreat and abandonment.
Under this option, settlements would move critical infrastructure
and housing away from the water’s edge and have soft flood defences
that would allow water into previously-protected areas.
The advantages of such solutions are long-term sustainability and
cost savings, but of course there are down sides as well -
investment in property and infrastructure would be lost and there
are real difficulties translating much of this from the drawing
board to reality - is it possible to relocate residential areas,
for example?
The next option addressed by the report is that of building bigger
and better flood defences.
The report questions the practicality of trying to maintain the
status quo in a changing environment.
“Many of the hard engineered defences of the 20th
century have been criticised for being unsustainable, reducing
access to water, damaging to coastal habitats and costly to
maintain and improve,”
the UK’s coastal towns and cities as rising sea levels and man-made
constraints conspire to increase the risk of inundation.
edie (January 14, 2010) - A joint report from the
Institute of Civil Engineers (ICE) and RIBA spin-off building
future attempts to spark a wider debate by using military metaphor
to look at the three broad options - retreat, defend or
attack.
Pulling back from the coastline and estuaries to avoid catastrophe
is one option, says the report, making a distinction between a
managed retreat and abandonment.
Under this option, settlements would move critical infrastructure
and housing away from the water’s edge and have soft flood defences
that would allow water into previously-protected areas.
The advantages of such solutions are long-term sustainability and
cost savings, but of course there are down sides as well -
investment in property and infrastructure would be lost and there
are real difficulties translating much of this from the drawing
board to reality - is it possible to relocate residential areas,
for example?
The next option addressed by the report is that of building bigger
and better flood defences.
The report questions the practicality of trying to maintain the
status quo in a changing environment.
“Many of the hard engineered defences of the 20th
century have been criticised for being unsustainable, reducing
access to water, damaging to coastal habitats and costly to
maintain and improve,”
It says. “However, they have
provided protection and reduced risk from flooding, allowing
activities to go on uninterrupted in the built environment.”
It suggests that some of the problems might be averted by taking an
over-arching view of the problem, rather than addressing localized
issues piecemeal.
But the report cautions that this is likely the remain a costly and
difficult approach - though imaginative solutions such as allowing
developers to build shoreline leisure facilities on top of defences
at the price of picking up a share of the bill might offset some of
the costs to the public purse.
The final option - attack - on the face of it sounds
impractical.
But, according to the report, engineering has moved on since the
days of King Canute and there are opportunities to build out into
the sea, as demonstrated elsewhere in the world. “There is massive
development potential to be gained for coastal cities by building
out onto the water,” says the report.
“This further reduces the need to sprawl into the countryside and
ensures their sustained social and economic vitality. Although it
leaves parts of the city still vulnerable to flooding, can the long
term benefit of new development outweigh this risk?”
It cites examples of how man has lived with water for centuries,
from stilted structures to land reclamation.
These strategies of Attack could unlock a vital planning tool and
give flexibility to our extremely dynamic 21st century cities,”
argues the report.
“Moreover, it could encourage a new breed of developers to fill
this gap as demand for the prime waterfront sites grows. This
commercial competition will need to be matched in long-term
management and responsibility.
“If new development in coastal cities starts
to prepare for rising sea-levels now, the livelihood of the city
could be maintained for generations to come.”To illustrate
its points, the report also looks at what might happen if two
flood-prone coastal cities - Hull and Portsmouth - each chose to
retreat, defend or attack.
target=”_blank”>The full report can be viewed here.
provided protection and reduced risk from flooding, allowing
activities to go on uninterrupted in the built environment.”
It suggests that some of the problems might be averted by taking an
over-arching view of the problem, rather than addressing localized
issues piecemeal.
But the report cautions that this is likely the remain a costly and
difficult approach - though imaginative solutions such as allowing
developers to build shoreline leisure facilities on top of defences
at the price of picking up a share of the bill might offset some of
the costs to the public purse.
The final option - attack - on the face of it sounds
impractical.
But, according to the report, engineering has moved on since the
days of King Canute and there are opportunities to build out into
the sea, as demonstrated elsewhere in the world. “There is massive
development potential to be gained for coastal cities by building
out onto the water,” says the report.
“This further reduces the need to sprawl into the countryside and
ensures their sustained social and economic vitality. Although it
leaves parts of the city still vulnerable to flooding, can the long
term benefit of new development outweigh this risk?”
It cites examples of how man has lived with water for centuries,
from stilted structures to land reclamation.
These strategies of Attack could unlock a vital planning tool and
give flexibility to our extremely dynamic 21st century cities,”
argues the report.
“Moreover, it could encourage a new breed of developers to fill
this gap as demand for the prime waterfront sites grows. This
commercial competition will need to be matched in long-term
management and responsibility.
“If new development in coastal cities starts
to prepare for rising sea-levels now, the livelihood of the city
could be maintained for generations to come.”To illustrate
its points, the report also looks at what might happen if two
flood-prone coastal cities - Hull and Portsmouth - each chose to
retreat, defend or attack.
target=”_blank”>The full report can be viewed here.
