All language subtitles for D D S01E07 Floods disasters 1080p AMZN WEB-DL DD2 0 H 264-playWEB_track3_[eng]

Water may seem harmless,

but in huge quantities,

it can be an enormously
destructive force.

It only takes 15 centimeters
of floodwater

to knock a person
off their feet.

A flood’s destructive power
can be quick and unpredictable,

giving people little or no time

to escape
from its ruinous path.

In this episode
of Deadly Disasters,

we’ll focus on one
of the worst floods

ever to occur in America,

following the breach of levees
along the Mississippi,

which unleashed
a torrent of water,

causing death and destruction
over a vast area.

We’ll also focus
on two other recent disasters

such as the floods in Germany,

when two of the largest rivers
in Europe

burst their banks,

and a terrifying overflow
in New York,

where more than 400,000
of its residents

were put at risk of inundation.

You would imagine
that hurricanes, tornadoes

and earthquakes might be
the most dangerous and deadly

of all the natural disasters,

but you would be wrong.

Flooding causes
more deaths worldwide

than any other disaster,
apart from famine.

They can occur
in a number of ways.

As water falls to the ground,

it will seep away
into the soil.

But if it falls faster
than the ground can absorb it,

there will be a risk
of flooding.

One of the biggest changes
that we’ve seen,

in terms of flood risk,

has been because of the way
we’ve managed our landscape.

We now have a lot
of concrete areas,

which means that if it rains,
it’s going to run off

really, really quickly
to the river,

and we’re going to get
those high flood peaks.

So when we change
our landscape in this way,

we can’t use that landscape

as a natural defense
against floods anymore.

It won’t soak up
that rainwater like a sponge.

Instead, it will cause
the water to run off

really quickly
to the river.

Water will pose a risk

to life and property

as it travels downhill
through channels,

such as streams or rivers,

which can turn
into deadly torrents.

Cities contain systems
and infrastructure

to transport rainwater

into appropriate basins
and reservoirs.

Usually, the infrastructure
does its job,

and you never have to think
about where the rain goes

when it runs off.

The problem with the drainage
system is dimension.

The dimension of the draining
system is usually very low.

It’s built to get rid

of the normal rainfall
in a normal year.

And if you have
extreme rainfall,

you have too much rain
for the drainage system,

and you get
the urban flooding problem.

Because the water

can’t drain fast enough,

it will begin to rise,
sometimes into homes.

If the water drainage for the
city discharges into a river,

this can also cause flooding.

There are many different ways
in which flooding can occur.

Overbank flooding happens
when too much water from rain,

or the melting of ice,

tries to flow down
a natural course like a river.

Unusually heavy rain,

or snow melt
near the source of a river,

can lead to vast amounts
of water

flooding into the wide-reaching
network of brooks,

small streams and tributaries
that feed into the river.

In this way, a huge amount
of water from a large area

is delivered to
the single channel of a river.

When the amount of water
reaches a critical level,

the banks,
or the natural flood plains,

can no longer contain
the water spilling over.

This often occurs at
the lower reaches of a river,

which may be densely populated,

causing extensive damage.

In mountainous regions,

where streams tumble down
steep hills,

water that overflows will move
rapidly down the hillside,

causing more violent damage,

as it finds its way
to level ground.

Most floods take hours
or even days to develop.

Excess water from rain or
melting ice builds up slowly,

and any people living
in the danger zone

are given time to prepare

and take evasive action
or evacuate.

The level of the water
was about-- What? Knee deep?

And that’s when we had realized

that the water wasn’t going
to stop rising.

It was either stay or get out.

And we weren’t gonna risk it,

so we got out
as quickly as possible.

But that is not
always the case.

A flash flood event

can occur so quickly
after the trigger event

that there is little
or no warning.

In 40 minutes,
it was all flooded.

Really, in 40 minutes.

I mean, it just arrived and then
you see the power of nature.

When this kind
of thing happens,

what else can I do?

Can you stay home?
No, you can’t.

You just have to go out
and just help whatever you can.

Floodwater will rise quickly

and move rapidly,

instantly turning
a babbling brook

into a thundering
wall of water

and sweeping everything
in its path downstream.

I can’t get to the bridge.

The local area’s all flooded,

so there’s no way of me
getting there, at the minute.

The coastline at the edge
of a large body of water

is particularly vulnerable
to flooding

brought on by waves
and storm surges.

Storm surges are when you get
a raised sea level,

and that is because you have
a low pressure,

from the storm itself,
pulling the water up.

But you also get a winds blowing
the water against the coast,

and wave overtopping.

We’ve never seen
anything like this.
No?

The waves are triple the size
of a human being.

This kind of coastal flooding
is associated with hurricanes,

tornadoes, storms
and tsunamis.

When these disastrous events
move from water to land,

this can create
a surge of water

that smashes onto the coast,

sometimes traveling
many kilometers inland.

It is worth noting,
that the winds in a hurricane

only account for
one out of every 10 deaths,

the rest are caused by
the flooding from storm surges.

Waves caused by storm winds
are also highly destructive,

but probably the most
devastating coastal floods

are caused by tsunamis.

These occur
when major disasters,

such as earthquakes or heavy
coastal rock or ice fall,

cause enormous disturbances
out at sea.

This turns into huge waves,

which can travel
across vast expanses of ocean

at high speeds.

The waves, which can reach
heights of 10 meters or more

when they reach
shallow coastal water,

cause terrible devastation
when they smash onto land.

The sheer amount of water
contained in a tsunami

means that these types
of floods

cause enormous loss of life
and destruction of property,

reaching many
kilometers inland.

More than 230,000 people
lost their lives

as a result of a tsunami

that struck southeast Asia
in 2004.

It was one of the deadliest
disasters of modern times.

In 2011,
a tsunami that struck Japan

killed more than 16,000 people

and caused
a nuclear power station

to go into meltdown.

Coastal flooding
is hugely destructive

and does some 3 trillion U.S.
dollars in damage worldwide.

Another kind of flooding

occurs when the nature
of a hillside changes.

Vegetation on slopes can help
slow the runoff of water

long enough for it
to soak into the ground

or find suitable channels
to drain

away from the hill
without flooding.

But following a drought,

and particularly
after a wildfire,

the loss of vegetation
and the hard-baked ground

will leave
the hillside vulnerable

to allow excess
rainwater runoff.

What you have is a landscape
that’s full of sediment,

and it’s also got nothing

to hold back the water
when it rains.

So then you get
all the rainwater

picking up all of the debris
from the fire,

or the sediment from the soil
that’s been under drought,

and that’s all carried down
into the river,

which can be very destructive
in the flooding.

A bout of exceptionally
heavy rain

can quickly result
in a flash flood.

Deforestation can also create
a major flood risk.

So deforestation
is very worrying

in terms of how the landscape
manages the floodwater.

So we don’t have
any trees anymore.

They’re not able
to trap the water.

So the water will just run
straight off the landscape.

It also means that the water
doesn’t soak into the soil,

because those roots
aren’t keeping the soil

very porous anymore.

So again, it increases
the runoff to the channel.

So our floods get worse
where we get deforestation.

A hillside that has had

its trees cut down
for wood production

or to clear land
for building and farming

is also much more liable
to flooding.

Another type of flooding
is caused by snow melt.

After a winter
of particularly heavy snowfall,

a sudden thaw
in mountainous areas

can lead to dangerous
volumes of water

draining from the slopes.

This effect can cause similar
damage to heavy rainfall.

Extreme rainfall is any rainfall
that is unexpectedly heavy,

or we get so much rain
over a period of time

that we weren’t
expecting that.

A dramatic temperature
increase

after a particularly
cold winter

can cause ice and snow
to melt very quickly

and overwhelm the rivers
in the valley below.

When a body
of frozen water melts,

a mixture of water and chunks
of ice may flow downhill.

Many communities
living in valleys

below very high mountains,

like the Himalayas
and the Andes,

face the threat
of a particularly terrifying

kind of flood:
the glacial outburst.

Glacial outburst floods
are very sudden,

and they are very large, indeed.

So we can have, for example,
an earthquake.

That means that we get a sudden
avalanche into a lake

that’s in the front
of the glacier,

and that can mean,
suddenly,

we have a great pressure
on the moraine

at the end of this lake,
which can burst very suddenly.

And all of that water will
rapidly go down the valley.

They can also be knocked
loose by rockfall,

or even an avalanche.

This poses a real danger
to the mountain communities.

As the glaciers
continue to melt,

more than 150,000 people
who live downstream

of these lakes
are living in constant danger.

Human interference in
the natural course of a river

can also lead to flooding.

Often landowners further up
a stretch of a river

may build dams
to protect their farmland.

But during a period
of high rainfall,

the water that would have

naturally flooded
over their land

is, instead, sent downriver,

where it can have
catastrophic effects

on communities built
in previously flood-free areas.

If water can be so dangerous,

why do so many people
choose to live so close to it?

Since prehistoric times,

people have lived
by the seas and rivers.

They are a source of food
and give access to transport

and trading routes.

The land around rivers
also provides

highly fertile flood plains
to grow crops.

It should be remembered
that flooding

is a part of a natural cycle,

which has sustained humans
for millennia.

The silt that is left behind
when the floods recede

are rich in the nutrients
needed to grow crops.

In more recent times,
people have built homes

on picturesque coastlines
and river valleys

because they are attractive
places to settle.

And as the population rises

and pressure
for land increases,

developers have built
on reclaimed land,

aggravating the problem,
by removing the wetlands

which would have acted
as a natural buffer

against flooding.

So when we reclaim land
from the sea,

we have to keep the water level
lower under the ground.

And that means we have
to pump it all the time,

and we have to drain it
all the time.

And we have to just keep
managing it,

and keep managing it,

otherwise,
the sea will come back.

When a river
overruns its banks,

or the sea drives inland,

structures not adequately equipped

to withstand
the force of the water

are easily destroyed.

Water can push soil underneath
a building’s foundations,

causing it to crack or topple.

One of the most dangerous things
that people do during a flood

is they try
and drive through it.

And it only takes
about 30 centimeters,

which is about 6 inches,

of floodwater
to sweep the car away.

And people die
from this every year,

by trying to drive through it.

Now, you can imagine trying
to walk through a flood,

and it does depend how fast
the water is flowing.

But generally, you really should
not be walking through a flood.

I was swimming.

I had my little daughter
in one arm,

and I’m paddling
with the other,

going with the current,

trying to stay away from debris
and houses

and whatever
that were piled up over here.

When the waters
finally recede,

they leave the affected areas
covered in silt and mud.

The water and the landscape
may be polluted

with hazardous materials,
sharp debris,

toxic pesticides,
fuel and untreated sewage.

Drinking water
may be contaminated,

leading to outbreaks of deadly
waterborne diseases,

like cholera, typhoid
and hepatitis A.

We had as much as 15 feet
of water here.

So anyone who lived
from here towards the gulf,

their houses were completely
underwater, destroyed.

They had no medicine for their
heart, blood pressure, diabetes.

To defend against flooding
in at-risk areas,

massive efforts
have to be made.

Hugely ambitious
engineering projects

attempt to stop floodwaters,

or redirect them
away from communities.

One of the places
built on reclaimed land

which illustrates this
perfectly is New Orleans.

An extensive levee system,

coupled with a network
of pumps,

attempted to protect the city,

but failed
with deadly consequences,

when it was hit
by the storm surge

accompanying Hurricane Katrina in 2005.

So on one hand,
levees protect people.

That’s what they are made for.

But we also see
that if we have a levee,

then the floodplain
is disconnected from the river.

The floodwater cannot spread
across the floodplain.

And this may increase the risk,
or the hazard,

for the people
who are living downstream.

So when you put up levees,

it means that you are creating
a channel,

which means that
if you get rainwater

going towards that channel,

it will rise much,
much more quickly,

because there’s no room anymore

for the water to spread out
onto its natural floodplain.

So, what you have actually done
is channelized all that water,

and it will run quicker.

It will run with more power,

and that can actually cause
more damage

in certain circumstances.

In the Netherlands,

where 50 percent
of the country

is either below
or very close to sea level,

they have built
a flood protection system

designed to the point

where the chance of failure
in any given year

is roughly one in 10,000.

The Dutch have said,
"We have to protect

against the one in 10,000 chance
of a flood from the sea."

Whereas New Orleans,

it’s unlikely to be more
than one in 200.

So a much higher standard in
protection in the Netherlands,

but obviously,
at a much higher cost.

After a disastrous flood in
1953 that killed 1800 people,

the Dutch built huge dams

to supplement the 22,000
kilometers of dikes.

There was a total commitment
to keeping the water out.

People usually believe that
they are protected from a dike,

but usually,
it’s just a problem

of the magnitude
of the flood event.

There’s always a flood event
which is bigger than the dikes,

or the levees.

And, um, there’s always
a residual risk,

even if there are dikes,

so it’s never a good idea
to construct buildings

in areas which have
a flood hazard.

Cities now use parks
and public spaces

as emergency reservoirs
for the floodwaters

generated by severe rainfall.

They also use highly advanced
computer modeling

to predict
with extraordinary accuracy

where and when floods
will occur

and how severe
they are likely to be.

So when we’re predicting floods,

we use computer models
of the Earth’s system.

So we take in the rain that’s
coming from the atmosphere,

and then we get that
falling onto the land.

And we use the physics
of the land’s surface

to work out where the water
is going to go,

and how it gets to the river.

And then how much water
will be in the river.

When we think about flooding,

we think about how big
that flood event will be.

Sometimes, those floods
happen quite often,

but they’re quite small.

Other floods will be
much, much bigger,

and they will happen
more rarely.

So we try and work out
whether it’s going to be a big,

but rarer flood,

or it’s going to be a small,

and one that happens
quite often, flood.

Many scientists
define certain rare

and extremely
destructive floods

as "one-hundred-year floods."

The term "one-hundred-year
flood" is extremely unhelpful,

because it gives the impression

that you’re going to get
a flood every 100 years.

But it just doesn’t work
like that.

It’s worked out over a very
long period of time,

and it means that on average,
every 100 years,

you would get this flood.

But that could mean
that you’d get flooding

in two consecutive years.

So it really is
a very unhelpful term.

It’s more helpful, I suppose,
to think about it

in terms of how likely
it’s going to happen.

So we might get
a "one-hundred-year flood"

happening next week,

and then we might get one
the following year.

So we are definitely seeing
that extreme rainfall

is becoming more frequent

and more heavy in
different places in the world.

And that’s very worrying.

Of course, it means that
if it’s raining more heavily,

we’re going to get more water
running off to the river,

and an increased flood risk.

To count as extreme rainfall,

there must be more rain
in a day

than the top 1 percent
of daily rainfall

throughout the total period
being studied.

These sudden bursts of rain

put severe strain
on the man-made features

designed to control water.

Drains overflow. Dams burst.

Levees get breached.

So it is no wonder

that with up to 50 percent
heavier downpours,

we are going to see
more flooding.

Extreme rainfall
that leads to flooding

can be a lot of rainfall
falling very, very quickly.

Or it can be: It’s raining,
and raining, and raining,

several storms passing over
in a couple of weeks,

which just then
will cause the flood.

One of the worst floods

in the history
of the United States

occurred in 2011,
along the Mississippi river.

The extraordinary flooding
was blamed on heavy snow melts,

three large rainstorms,
and tornadoes earlier in April.

These events also triggered
flooding from the Ohio River,

which added
to the mass of water

flowing into the Mississippi.

Thousands of square kilometers

of agricultural
and residential land

were engulfed by water
that cascaded over the banks

of the Mississippi River.

There were areas
deliberately flooded

when levees were blasted,
and spillways opened

to divert water
away from large settlements.

This was, by no means,
the first time

the mighty river
had flooded.

The 1993 Mississippi flood

was the costliest U.S. flood
of the last century,

responsible for about
15 to 20 billion U.S. dollars

in economic losses.

More than 600,000
square kilometers

in nine states were flooded.

Knowledge gained
from this previous disaster

led the federal government
to construct

numerous levees and spillways

to contain
and channel floodwaters.

This meant that in 2011,

the path of the torrent was,
to a certain extent,

predictable and controllable.

It’s very difficult
to get the balance right

between protecting
pieces of land with levees

and having this problem
that the levees might fail,

under certain circumstances.

So if there’s enough water,

they will be overtopped.

And sometimes,
they will fail

because there’s always
this leftover risk

when you try and put up
these defenses.

You could build them
as high as you like,

and there would still be the
chance that they might fail,

under certain circumstances.

So one of the interesting
things about levees,

is there is something
called "the levee effect,"

which means that people feel
safer when a levee is built.

And that means they often move
into the area behind the levee,

and then, actually,
the flood risk is greater,

because those people
are there in that area.

And should the levee
be overtopped, or fail,

then there will be quite
substantial damage

and possibly, loss of life.

To understand
why the Mississippi

is such a dangerous river,

you need to look
at its geography.

The Mississippi basin
has a wide top

that stretches from Montana
and southern Canada in the west

to New York state
in the east.

The river then curls south
for more than 3700 kilometers

through the United States,

emptying into
the Gulf of Mexico.

The river and its tributaries
touch parts of 31 states.

Problems with flooding occur
on the Mississippi

because it gathers water
from such a vast area.

Its watershed is the fourth
largest on the planet,

covering a 3.2 million square
kilometer expanse

across 31 states.

Because of their
abundant network

of roughly 250 tributaries,

water from rain
and melted snow

can travel to the river

from surprisingly great
distances,

in some cases, as far away

as the Rocky Mountains
in the west.

Rain that falls in the Dakotas

right up on the border
with Canada in the north

will eventually travel down
the Mississippi

all the way to the Gulf
of Mexico in the south.

Throughout the spring of 2011,

the U.S. Army Corps
of Engineers

monitored both
the coming of floodwaters

and the dangers
faced by the population

living on or near the bank
of the Mississippi.

Although huge efforts were
made to control the flooding,

nothing could be done
to stop it.

The disaster
unfolded gradually,

day by terrifying day,

as the cresting of floodwater,
slowly but steadily,

made its way southwards

down the length
of the mighty river.

It breached levees
in Missouri,

Arkansas, Mississippi
and Tennessee,

leading to the destruction
of property,

the evacuation of many
thousands of residents,

and several deaths.

Louisiana governor
Bobby Jindal

declared a state of emergency,

expected to extend
for a month.

He later requested
the assistance

of 1500 National Guardsman

to prepare for an opening
of the Morganza Spillway,

in order to shift potentially
devastating flood waters

away from the highly
built-up areas.

The rising Mississippi river

welled over
into downtown Memphis streets

and threatened homes
on Mud Island,

a community
of about 5000 residents

connected to downtown Memphis
by a bridge and causeway.

Concerns were growing that
the levees might be breached

in the Louisiana cities
of Baton Rouge and New Orleans.

This would have displaced
many thousands of people

and shut down a network
of petroleum refineries

responsible for a large part
of American petrol production.

On the 3rd of May,

U.S. President Barack Obama

declared flood-damaged areas
of Tennessee

a federal disaster zone

as the Mississippi River
crested there.

Officials downstream
in Louisiana

began evacuating inmates

from the Louisiana State
Penitentiary in Angola.

the largest
maximum-security prison

in the whole
of the United States.

The U.S. Army Corps
of Engineers

warned that if the pressure of
floodwaters on the Mississippi

was not relieved
by opening spillways,

New Orleans could be flooded
by 6 meters of water.

In order to save Baton Rouge,

the Morganza Spillway
was partially opened

on the 14th of May.

This was the first time
this had occurred since 1973.

More channels reopened
in the following days.

Opening the Morganza Spillway

released 17,000 cubic meters
of water per second,

nearly 2.8 times more than
the Bonnet Carre Spillway,

which had been opened
further north.

But unlike that spillway,

opening the Morganza
would cause flooding

throughout rural communities
near the Atchafalaya Basin,

into which the spillway
would be emptied.

As a result
of the spillway opening,

a rush of water headed south.

The waters deliberately
released from the Mississippi

drained into the Atchafalaya
River basin,

covering a vast majority
of its cropland.

In the state’s
French Louisiana region,

homes and local farmland

were sunk below 3
to 6 meters of water.

In the later weeks of May,
the Mississippi River

had reached record levels
in many areas,

but was now, thankfully,
beginning to recede.

State officials began the
process of checking properties

that had been evacuated to see
if they were safe to live in.

Many of the buildings
were condemned

or would require
complete reconstruction.

Chemicals from floodwater that
entered the Gulf of Mexico

led to an increase
in algae blooms

that deoxygenated the water

and severely affected fisheries
already suffering

because of the effects of
the Deepwater Horizon oil spill

of 2010.

The Army Corps of Engineers

estimated it would cost
1 billion U.S. dollars

to repair the damage
caused by the flood.

Congress allocated
802 million U.S. dollars

to the U.S. Army Corps

to locate and restore

the most vulnerable areas
of flood defenses.

I feel more secure since
they done raised the levees.

And at first, they wasn’t
prepared for what happened.

But now, I think
they’re more prepared.

Despite all of its advanced
flood defenses,

the river systems of America
are still likely to overflow.

But it isn’t only the mighty
rivers of the United States

that are vulnerable
to flooding.

Europe has the Danube,

the Loire and the Rhine.

There is also the Elbe,
which runs all the way

from the mountains of the Czech
Republic to the North Sea.

When it burst its banks
in 2013,

it carried floodwaters
right through Germany,

killing 25 people

and racking up 3 billion Euros’
worth of damage.

Southern and eastern Germany
were particularly affected.

But several other countries
were also hit by floods--

Austria, Switzerland, Poland,
Hungary, Slovakia,

Croatia and Serbia
were all touched by a disaster

that reached right across
central Europe.

We came here to protect
from Duna.

The water is very high,

so we have to make sandbags

to protect us from the water.

So I hope it will be okay.

The June 2013 flood

was the most severe
large-scale flood

to strike Germany
in at least six decades.

Many flood gauges along
the Elbe and Danube rivers

showed record water levels.

The flood severity index,

a measure which combines
both the flood’s magnitude

and the area affected,

is almost twice as large
for this event

as the index for the previous
floods of August 2002.

At that time,
it was the most

expensive natural
disaster for Germany.

The month when the flood
occurred, in May,

was unusually wet.

We had a lot of rainfall
before the event started.

In some regions,
it was twice as much

as the mean monthly rainfall.

And then, at the end of May,

there was a period
of two to three days

where we had another period
of extreme rainfall.

And this rain fell on soils
which were already saturated.

Then the water
cannot infiltrate.

It runs across the surface
to the river,

and causes, of course, a flood.

And that’s it.

So it was caused by a very
strong pre-event rainfall,

and then there was
a storm event,

and the soils were already
saturated.

Almost all the rivers
in Germany

showed high water levels,

with especially severe flooding

occurring along the Danube
and Elbe rivers.

Warm and moist air masses
were continuously drawn in

from the sub-tropics
in the south

towards northern
and central Europe.

Several low-pressure systems,

which swept in
one after the other,

brought about long periods

of widespread
and intense rainfall.

We have to consider that
the last big event, in 2002,

came after a period of,
let’s say, 100 years,

where there was no major flood
at the Elbe basin.

There was not so much investment
in flood protection.

After the flood event of 2002,
many things were done--

Information systems
were improved.

Early warning systems
were improved.

The measurement systems,
the gauge system, was improved.

There were management plans
for river basins,

for parts of the Elbe basin,

and there were
some technical measures,

which were planned already.

Dikes were improved.

They also restored
many old dikes.

And these restored old dikes,

they worked quite well
when the flood in 2013 came.

In 2002, we had
a lot of dike breaks

because the dikes were not
managed very well.

But after these 11 years
between both events,

many dikes were enforced.

And these dikes
worked very well.

Breaking dikes, in 2013,

appeared only in areas where
they were not restored yet.

The most intense rainfall

occurred between the 31st
of May and the 4th of June

over a huge area
of saturated ground,

covering most parts of
southern and eastern Germany,

and in particular,

the catchments of the Danube
and Elbe.

There was so much water
in the Rhine

that parts of it had become
too dangerous for shipping.

Swathes of suburban Prague
were left under water

after the Vltava River
burst its banks.

This was bad news
for German towns further north,

as the surging Vltava
would carry its floodwaters

all the way to the point
where it merged with the Elbe.

Thanks to strong
metal barricades

securing Prague’s
historic city center,

the waters shifted north
towards Germany.

The Elbe rose to alarming
levels in Saxony,

as water moved in
from the Czech Republic.

Passau, a German city
on the Austrian border,

was also now under threat.

Passau is often called
"the city of three rivers,"

because of its position
at a point where the Danube,

Inn and Ilz rivers
all intersect.

But that location
proved the city’s undoing

when its river hit a record
water level of 12.75 meters--

The highest since
a historical flood of 1501.

When the inevitable happened,
and the river burst its banks,

whole areas of the city
disappeared underwater.

The streets
looked more like canals.

In the area
around the city of Leipzig,

Saxony’s most populous city,

some 6000 people
had to be evacuated.

In the Bavarian city
of Deggendorf,

located on the river Danube,

the levees burst
on the 5th of June,

allowing torrents of water
to flow into the city.

In Dresden, one of the main
bridges across the river

had to be shut off to traffic.

Wide areas were flooded,

but the historic parts
of the city were spared.

People had worked frantically
to shore up defenses

as the river peaked
at nearly nine meters,

7 meters above
its normal level.

Thousands of emergency
personnel and residents

had worked through the night

to fill up sandbags

and build up flood barriers.

Next to be hit were the cities
of Bitterfeld and Halle.

Chancellor Angela Merkel
visited Bitterfeld

on the 6th of June and promised
further emergency aid.

Throughout Germany,

60,000 local emergency
personnel and aid workers

were deployed
to battle the floods,

as well as 25,000 federal
disaster responders

and 16,000 soldiers.

Deggendorf was stricken
by a third levee break,

with floodwaters pouring
into entire neighborhoods.

Many homes
remained underwater,

and authorities warned that
the dam holding back the water

was in a deeply
precarious state.

In East Germany,

about 23,000
Magdeburg residents

were forced to evacuate
after a dam failure occurred

on the flood-swollen Elbe.

Further along the Elbe,

hundreds of people were
evacuated from their homes

in the towns
of Stendal and Aken.

Authorities demanded
that 150 people evacuate.

In total, 45,000 people

were told to abandon
their homes in Saxony-Anhalt,

as the state bore
the brunt of the swollen Elbe.

It’s a difficult thing
to tell these people

that they can’t
live there anymore.

If you live somewhere
for 30 to 40 years,

something like that, try to
imagine to tell such people:

"So you have to go, you have
to live somewhere else.

You can’t do this."
And so it’s...

The theory is very good,

not to build anymore in areas
which are affected by flooding,

but in practice, this faces
quite a lot of challenges.

Fischbeck, a 700-person village
in the district in Stendal,

experienced a total inundation

following the breach
of a nearby river dike.

There are two
very dangerous things:

The ones in the lowlands

where there’s widespread
inundation of areas,

which causes lots of damage.

And in addition to that,

which is even more dangerous,
if a dike breaks.

People who are believed
to be protected from the dike.

And the second problem
is in the mountain areas,

where the floodwater
comes from.

And you have very,
very short early warning times

and very rapid increase of the
water levels in the rivers.

And the flood
rushes through the valleys.

And that’s quite dangerous
in the mountain areas.

Two Army helicopters
were then deployed

to drop giant sandbags on
the gap in the flood defenses,

but their efforts
to repair the dike failed.

Around 700 soldiers worked
to build a dam of sandbags

to protect a power substation

in the badly hit area
of Rothensee,

in a bid to stop
the electricity from failing.

Train travelers faced severe
delays and cancelations

when a railway bridge

on the line
between Berlin and Cologne,

Frankfurt and Amsterdam
had to be closed.

More than 52,000 people
had to be evacuated

during the June 2013 floods.

The total number of fatalities

in all of central Europe
was 19.

The German Farmers’ Association

estimated that 2500 square
kilometers of grasslands

and crop fields
were flooded.

Large industrial companies,

like the car manufacturers
Porsche in Leipzig

and Volkswagen in Zwickow,

as well as Südzucker
in Zeitz,

the largest sugar producer
in Europe,

had to stop their production
due to direct flood effects,

or the indirect effects

of disruption
to their supply chains.

Although there had been
many lessons

learned from
the catastrophic flooding

that had occurred
10 years before in 2003,

some towns were better
prepared than others

when the waters rose again.

The town of Grimma,
for example,

started to build
a defense wall in 2007,

but it was half finished
and then delayed.

The completion of that wall

might have prevented
their second flood

in just over 10 years.

Dresden, on the other hand,
was one of the success stories.

By the time
the 2013 floods hit,

its overall
communications apparatus

was used effectively to protect
vast parts of the city.

Both the new mobile and older
stationary protection walls

did their jobs successfully.

And for the catchment area
of the Weiseritz River,

there were proper
runoff pathways,

all of which avoided severe
consequences for Dresden.

So the Elbe flooding
triggered a rethink, I suppose,

about how we work together
as a community

to help people
in areas at flood risk.

And one of the things you can do

is provide an earlier warning
of things that are gonna happen.

The European Commission has set
up a new flood forecasting

and early warning system
to help give an early warning

to the community in Europe
when a large event is coming.

So that can tell you,
maybe, 15 days ahead

that a large event is coming.

It can also help European
countries work together

to get equipment
in the right place,

at the right time.

It’s a terrifying prospect

when flooding threatens
to overwhelm a tightly packed,

densely populated
urban environment.

And there can be few places
in the world

that fit that description
better than New York City.

In the autumn of 2012,
both the city

and virtually all
of America’s Eastern seaboard

were pummeled
by Storm Sandy,

the deadliest and most
destructive hurricane

of that year’s Atlantic season.

Fifty million people
were impacted by the storm,

with roughly a million
instructed

to evacuate their homes.

We gotta get out,
it’s imperative.

At this point, it was just,
like, a matter of just sanity.

We got no hot water,
no electricity.

This was unprecedented.

The damage done here,
I couldn’t have imagined.

In New York City,
43 people were killed,

many from drowning
in the floods

the day before the storm
made landfall.

New York’s Metropolitan
Transportation Authority

closed the nation’s
largest transit system.

Subway and commuter
rail services

were suspended at 7 p.m.,

and bus services at 9 p.m.

Governor Andrew Cuomo
mobilized the National Guard,

while New York City Mayor
Michael Bloomberg

ordered evacuations
in all low-lying areas,

as well as the closure
of public schools.

More than
70 evacuation shelters

were open around the city

in readiness
for the imminent disaster.

This one put fear in my heart.

And I think everybody else
felt the same way.

It’s unbelievable...

Sorry.

There are not even words
to describe it.

I mean,
it’s absolutely insane.

The water was moving by
three feet every four minutes.

The storm first struck the
coast of southern New Jersey

with a storm surge inundating
the beachfront neighborhood

of Breezy Point,

causing hazardous electrical
short circuiting

that burned 110 homes
to the ground.

We haven’t seen a storm
like this in about 30 years--

The last time it was like this,
and it wasn’t this bad.

More than 190 firefighters

battled the blazes
for hours into the night.

They were still
putting out flames

more than nine hours

after this nightmare
first began.

Floodwaters rushed down

New York’s 108-year-old
subway system,

flooding seven major tunnels.

Seawater flooded
into the Battery Tunnel,

cutting off the city
from Long Island.

And the Holland Tunnel,

connecting New York City
to New Jersey,

was gorged with floodwater.

I’ve never seen
anything like it.

I think it’s the worst storm,
they say, since 1938.

There’s not going to be
transit for a while.

There’s not going to be power
for I don’t know how long.

That’s the major thing
is the power

because we live in a high rise,

so there’s no way up and down
except to walk the steps.

We don’t know what to expect.

How long it’s going to last.
How bad it is.

And how it’s going to get
back to normal. No idea.

Power was lost
in some 500,000 homes,

plunging Lower Manhattan
into darkness.

The overwhelming surge

left much of New Jersey’s
Atlantic City underwater,

leading 30,000 residents
to evacuate.

There were eight drownings
on Staten Island,

occurring within eight blocks
of one another.

It was the highest
concentration of deaths

attributable to the storm
in the United States.

In Hoboken, across the Hudson
from New York City,

Mayor Dawn Zimmer warned that
live wires were dangling

in standing water,

which was becoming
contaminated with sewage.

The National Guard
evacuated deluged homeowners

and distributed meals.

U.S. President Barack Obama

and New Jersey Governor
Chris Christie

toured the state of New Jersey

to survey the devastation
two days after the huge storm.

In the immediate aftermath,

centers were set up
on Coney Island,

the Rockaways
and parts of Staten Island

so that meals and bottles
of water could be distributed.

As the floodwaters receded,

New York began
the long road to recovery.

The cleanup operation
ran 24 hours a day,

as fleets
of several hundred trucks,

river barges and tugboats

moved an estimated 3 million
cubic meters of debris

to landfills in upstate
New York and Pennsylvania.

Flood management is a very,
very, very wide field.

On one hand, you have technical
measures, like dikes,

or retention basins,
or dams.

But as an experience
from the last, let’s say,

20 to 30 years, we know

that technical protection
is not enough.

We can protect to some degree,

but there’s no full protection.
It’s not possible.

We can manage flood events,
to some degree,

and this management
includes even much more

than just technical measures.

It also includes the nature
of water retention,

to keep the rainwater
in the headwater areas,

where it comes from.
Where the flood is generated.

It also includes
a lot of precaution.

People are informed
that they know what to do,

what they have to do.

And the buildings are
constructed in the right way

to withstand flood events.

People have their own
financial resources

to deal with a flood event,
with damage.

Um, there’s a lot of things

which can be done
for flood management.

It’s very difficult
to work out

whether floods are
occurring more frequently

because they are very,
very variable.

So we might get a flood-rich
period of a couple of decades,

and then it might be drier
for a couple of decades.

But over time,
I think we are seeing

a more serious flooding
happening.

We have got records going back
several hundred years,

in places in the world.

And so it does seem like we’re
getting these bigger events

happening more often.

If you’re aware
of when it’s going to flood,

or at least
what your flood risk is,

then you can make yourself
resilient to floods.

So you can build back better.

You can make your house
flood proof.

You can think about
how you design your city,

so that there is room
for the water.

So although we live in areas
that are at risk of flooding,

we can do something about it
to make our lives better,

when it does flood.

One of the most important
things that we can do

to be prepared for floods

is to understand
how the landscape works.

So to really appreciate
the fact

that we need to store
our flood water somewhere...

We can’t just magic it away.

We have seen that floods can
strike virtually everywhere.

From the picturesque
river towns

of southern Germany,

to the urban powerhouse
of Manhattan.

From mountaintop communities
high in the Himalayas,

to the cornfields
of the Mississippi Delta,

it would seem that few places
on Earth are safe

from one of Mother Nature’s
most immense deadly disasters.