Transcriber: Fizza Naaz Reviewer: Amanda Chu
Climate change promises to bring many negative impacts -
extinctions, extreme temperature events, increased hurricanes -
but the most universally feared consequence of climate change
is flooding,
the idea that water will reach places
in our man-made environments and our cities
that were never intended to host it.
In climate adaptation,
resilience, the term "resilience"
is almost always associated with flooding now.
Our fear of flooding traces back to the story of Noah,
and the plot is a familiar one:
Mankind's misdeeds and excesses
bring about a terrible environmental event;
mankind uses technology -
in Noah's case, a very well-designed Ark -
and a rudimentary understanding of ecological systems -
in his case, animal husbandry -
to weather the storm and save mankind.
Like Noah,
we actually have the technology to protect ourselves from floods.
But the problem is not a technological one;
the problem is really a social one.
Our cities are not just physical places with buildings and roads;
cities are a complex set of social and legal relationships.
And unless we adapt to a design and a plan
that can accommodate those things,
we are going to be in trouble.
So I submit that in order to more fully adapt to flood change
that we are going to have to rethink our entire notions of public and private
and how we relate to each other
in these environments that are going to be threatened by flooding.
We've had the technology to separate ourselves from water
for centuries.
It's simple.
You put a pile of dirt or stones between you and the water,
and generally you're safe for quite a while.
More sophisticated versions of this
do other things besides keeping water away,
like this dam in the Netherlands,
which bounces the flow of the tides between one body of water and the other
and also provides a bridge to connect two dry pieces of land.
More current thinking
about protecting ourselves from flood waters
are trying to incorporate natural approaches,
such as this breakwater,
which not only softens the impacts of waves
but harbors and engenders and incubates all kinds of nice natural activity,
like natural grasses, oysters and things of that nature.
At the other end of the spectrum of current solutions
are what we call "deployable solutions."
These are the proverbial finger in the dike
that can be deployed at the last minute
and are meant to plug up those holes in our infrastructural system
where the land or the topography
are specifically very vulnerable.
But the problem with cities
is that, while these solutions are actually pretty simple,
cities are actually complicated places.
They are not just buildings and roads.
They are a complex and messy stew
of underground infrastructure, jurisdictional boundaries,
subways, drainage, utility companies,
all sorts of legal boundaries
that make up this sort of complex stew of what a city really is.
The most important thing about cities
is that they provide the infrastructure in the physical space
for us to navigate
between our private cells and our public space.
Cities provide the right kinds of boundaries
that allow us to coexist with ever-increasing densities of people.
Giambattista Nolli was perhaps the greatest cartographer ever, I think.
He mapped a famous map of Rome in the 18th century,
and what makes it so spectacular
is not just the detail with which he did it
but it's a map
that actually distinguishes between public and private space.
Rather than showing overall view of the city,
like an aerial view,
he cuts the ground plane in such a way
that you can see the ground floors
of all the public buildings that are publicly accessible -
so that every space that is publicly accessible,
including outdoor plazas and the interiors of public buildings,
like churches -
are rendered in white.
Any spaces that are private, such as residences or apartments,
are rendered in black or gray.
In North America, in the 20th and 21st century,
we also have these more nuanced understandings
of public and private space in our urban environments.
Take the stoop of a brownstone, for instance,
which is not just a series of steps
that get you to a parlor level of a townhouse.
That stoop describes actually a very important zone,
a zone that is both legally documented
but, more importantly, is a very critical social space
that allows the private to mediate with the public,
provides a protective layer;
it provides a place for socializing, knowing about your neighbors,
fostering other kinds of small economic activity.
The front yard is an important social space in our culture;
it's also legally enshrined in our zoning codes.
It has a name. It has dimensions.
It's embedded in the way that we order ourselves
relative to our urban environments.
The problem with legal definitions of front yards
or social activities in front yards
is that flood waters do not discriminate about such things.
Floodwaters like to go wherever they like to go.
There are really two solutions to this, about what to do -
what to do with that point
where floodwaters approach in the public realm
and begin to collide with a private realm.
One is to take private property and to simply elevate it.
The other is the reverse:
take the street, take the public property,
and you elevate that.
Neither of these solutions are particularly appealing;
I think, in fact, call them version 1.0 flood resilience.
In a typical sidewalk condition,
really, the only thing separating us from the public and the private
is this thin red line here.
This thin red dash line represents a property line.
That boundary doesn't do much good for us
when we're experiencing a flood event.
It will not discriminate
against private property or public property.
I think what we need to be thinking about
are configurations of public and private property
that are more complex, that have much more overlap
and will allow for things
like elevated sidewalks on private property,
cantilever building elements that come out over the public property,
some sort of more complex, nuanced dance between public and private realm
that will allow most of the private property, the building,
to withstand a flood event.
Long-term,
I think that we have to think about this not just two dimensionally
but at the block scale and the building scale.
How do we actually redesign entire city blocks?
How do we build in kind of templates for building typologies
that can adapt, long-term,
to what might be an elevated public ground in the future?
Take, for example, this idea of a kind of courtyard block
that might be fine for now and has its public realm happily at grade,
but imagine when the flood comes,
that you can actually build a whole separate set of streets
that comes right through the middle of that courtyard.
What you begin to see is an idea of a public realm
that literally begins to turn itself inside out.
And I believe that this is the kind of thinking
that will produce a much richer,
more livable, more sustainable, and more complex urban environment.
These kinds of urban forms are plentiful in pre-modern cities,
such as Stockholm, where this building is.
The actual entrance to this building is just a hole in the wall,
but when you get inside the middle of the block,
you realize that the front is actually in the back.
This is a beautiful example of the ways
in which, if we think beyond simple notions of front yard and backyard,
side yard,
that, if we think about turning
our urban environment and our sense of space inside out,
that we cannot only enrich our sense of what is public and what is private
and how individuals relate to communities,
but we can begin to use these techniques to help us adapt to flood risk.
I think that in the end,
designing for flood resilience is not just a technological problem,
it is not a simple design problem.
But I do believe that we have a kind of generational opportunity
to really rethink more boldly how we redefine our public realm
and how we think about how individuals relate to their collective community
and how to create much more vibrant and interesting complex cities.
Thank you.
(Applause)