Nature depends
on water. Without it, nature
can no longer exist. How much drought
can our ecosystem and waters withstand if the climate
changes over a relatively short time? When it comes
to climate change, we are only now just
beginning to feel the effects. Ecosystems are already
collapsing globally. On top of that, we are now
fearing the worst-case scenario. About 80% of the trees have
died. And nothing can be done. Here, we have a 300% overuse of water. I’m literally sitting on
what was a boat ramp. We are having such an impact
that we could kill the Colorado River. Itś a difficult
balancing act. No one can be without
drinking water from the tap. We are certainly headed for a
grave hydrological catastrophe. You could say that a violent
confrontation with nature awaits us. We are used to an
abundance of water. But that perception is changing
quickly thanks to climate change. Less water is leading to
frequent water shortages. This series raises the question:
What happens when the wells run dry? The Taunus mountains
provide most of the drinking water in Germanyś
Rhein-Main region. Ernst Kluge is the former head
of Wiesbadenś the water authority and ecologist Andrea Sundermann has
studied the impact of extracting water from the Taunus mountains
on the local nature. All over Germany, the consequences
of the drought are visible. As you can see, Im
walking dry-footed through what used to be a stream
that carried water all year round. Im literally standing
on this riverbed and you can see the gravel
underneath these leaves. Itś sad to see
the stream like this. It just confirms what we
have known for a long time: That water extraction
interferes with the ecology, with groundwater levels
and also drains the landscape. So, why are rivers
and streams drying up? We look for clues in a particularly
hard-hit region: Water-rich Bavaria. Simon Preiß from the Nuremberg
Water Management Office searches for a pond that is a
tributary to the Pegnitz River. You have to imagine that only a
few years ago this was all under water But thereś
nothing here. Where did the
water come from? And where
did it go? The two experts are looking
for the remnants of a spring. You can see that the water level
used to reach above this platform. Right. Incredible! Sure nature reacts
relatively quickly to rainfall. Just like when you water
your flowers in a pot. But what we are talking about here is
how it looks underneath the surface. Through our official
monitoring systems, we can see that
in recent years, the levels have not recovered
during the winter like they used to. And that's a
big concern. Water used to flow from
here and fill this pond. Now the water table
that's in the mountain behind us is even below this edge
where the water used to gush out. This area where the water used
to flow through is completely dry, as you can see. I have some images
from earlier this year where you can still
see some water here. Now itś basically
just a dried-out cave. The situation has never been
as critical as in the last years, because of the consecutive dry
summers and springs weve had. Where does our
groundwater come from? At the Potsdam Institute
for Climate Impact Research, Fred Hattermann analyzes
the German Weather Service's records of precipitation
and evaporation. How is the available water -
the water supply - changing? This corridor between
precipitation and evaporation is what later becomes
groundwater and flows into the rivers. That's the water
we can manage. But we are seeing this
corridor getting narrower. The annual average of
rainfall may remain unchanged, yet we have
less water. Thatś because our
winters are getting shorter. Warmer weather
means more evaporation, causing vegetation to
grow for longer periods. And winter is when the water
tables and reservoirs are replenished, in the phase where we
don't have green vegetation. However, that phase
is getting shorter, meaning that the same
amount of rain eventually leads to less water for
humans and nature. Over the past 50 years,
global animal populations have declined by
an average of 68%. And even though humans only
make up for 0.01 of Earthś biomass, we are responsible for almost all the
negative impacts on everything else. The Senckenberg Institute
in Frankfurt am Main has been researching
biodiversity since 1817. What is the correlation between
biodiversity and a drier climate? What weve been able
to show in our global study is that streams and rivers drying up
at the surface have become the rule, not the exception. 60% of all streams and
rivers naturally go dry. But when a stream that permanently
carries water begins to dry up, there are obviously massive
consequences both for the environment, and for the availability and for the
quality of the water for us humans. The consequences are becoming apparent
in Germany’s Rhine-Main region. A large part of the drinking
water for the 5.8 million people living here comes from
the Taunus mountains. For more than a century,
millions of cubic meters of water have been pumped out
of the ground every year. How does this plant,
operated by Hessenwasser, one of the largest water suppliers
in the region, affect nature? Ernst Kluge is the former head of
the water authority in Wiesbaden, one of the largest population
centers in the region. For years, Kluge has
documented the consequences of extracting drinking
water on nature. Behind me is an arm of the
Schwarzbach river that has gone dry. It’s dry throughout the year,
due to the water extraction that is located here above
us, the large Münzbergstollen. The consequences
for nature are serious. It has gotten
progressively worse because of the drought
in the past few years. One of Hessenwasserś customers is
the city of Oberursel, near Frankfurt. Oberursel’s public utility supplies
residents with drinking water. Managing Director
Julia Antoni and Technical Manager Dieter Gredig
explain where the water comes from. Picture the extraction area in the
Taunus mountains as a bathtub. And we’re extracting
water from this bathtub. But the Taunus
also has an outflow. Thatś the
Urselbach river. And the flow of the Urselbach
has to be at a certain level for us to be able to use our
water rights in the Taunus. The Urselbach river flows
through the entire region, and drinking water can’t be taken out unless the Urselbach
is carrying water. Andrea Sundermann from
the Senckenberg Institute has been observing
the river for years. Weŕe standing at the
point of the Urselbach that actually dries up
during the summer months. Itś easier to imagine if
you look at some pictures. This, for example, is
the view downstream and you can see that this channel,
this gravel bed, is completely dry. And that’s because drinking
water is being extracted from the upper reaches
of the Urselbach. And the water that's extracted
there, is what is missing here. Water for citizens
or water for the river? Itś a tough
choice. And what are the consequences
for the entire Rhine-Main region, which gets much of its
drinking water from the Taunus? Competition for water as a resource
has already become a fact and here, in the heart of Germany, the
demand for human drinking water is competing directly
with natureś needs. Not only is plant life affected
— aquatic life is hurting too. This also has an impact
on the biodiversity. We are lacking certain
species normally found here, because they can't cope
with the reduced flow of water. Our streams and rivers are among the
most biodiverse habitats in the world easily comparable to coral
reefs or tropical rainforests, only this diversity is underwater
and not immediately visible. Andrea Sundermann is doing
field work by the Urselbach river. She’s collecting samples
at several locations to document the
current biodiversity and for closer examination
in the laboratory. In Germany, only 7%
of all streams and rivers are considered to be in
good ecological condition, which means that 93% of water
bodies are in poor condition. And this despite the European
Water Framework Directive. The directive’s goal is to
achieve a good ecological status for all water
bodies by 2027. And we are
now at just 7%. That means that itś
impossible to achieve this target, which begs the question:
Why do we formulate targets that we know from the outset are
out of reach with our current efforts? What will Sundermann
find in today's samples? There should
be more. Not necessarily more
individuals, but more species. Overall, there are
several types of mayflies, caddisflies and
beetles missing. So, in that sense, we really have
a reduced species diversity here. Normally there are many, many more
species in a body of water like this. What are the consequences of such
reduced species diversity for nature? The decline of biodiversity is the
biggest challenge we face as humanity. On the one hand, once
something is lost, itś lost forever, and on the other hand, we don't
know what a 10, 20, or 50% decline in this diversity
will mean for nature, and ultimately for us in the long run. But human impact on
our waters is not limited to just extracting
drinking water. What we are seeing here is
the runoff from the Oberursel wastewater
treatment plant. It’s actually
purified wastewater. Downstream of this plant we
have a relatively high percentage of purified
wastewater in the river. So we have a very reduced
species composition there. Only a few
species can cope. Purified water
sounds harmless. But it contains
toxic residues from microplastics to
pharmaceuticals and pesticides. Discharged into our
streams and rivers. Scientists in Hanover, the
capital of Lower Saxony, are currently investigating
the impact on groundwater. This is where Ralf
Hiller's team comes in. Hanoverś environmental
agency has been taking a hard look at groundwater over
a long period of time. Since our drinking water is
mainly fed by groundwater, any adverse effect
on the groundwater will eventually also
affect our drinking water. The researchers first
collect a water sample. They use fishing line to
lower the receptacle 20m into the monitoring point and
then fill it up with groundwater. The water will be chemically
analyzed and is captured in this tube. We lower it down to the
bottom of this groundwater. Now that we’ve collected the water,
we can begin the chemical examination. The groundwater will first be screened
for residues in the laboratory and then experts will
look for living organisms. We have recently been
using more scientific methods, which allows us to look for
different kinds of microorganisms. If they were to find species that would
normally only be found on the surface, it would be evidence of surface
water mixing with groundwater. The underwater
camera sinks deeper and deeper into the
groundwater monitoring point, looking for
microorganisms. But a more detailed
examination is necessary. The water samples from
Hanover have been sent to the University of
Koblenz-Landau for analysis. Water ecologist Hans
Jürgen Hahn and his team will take a microscopic
look at the samples. This one is
quite interesting. The scientists suspicion
is confirmed when a small, almost transparent creature
appears under the lens. These seed shrimps
are always an indication of surface
water infiltration. This sample also contains
freshwater copepods, which are typical organisms
found on the surface. If you find those in
samples from groundwater or drinking water reservoirs, you know that something
is coming in from above. But are these findings really cause
for concern yet? And if so, why? The water that is seeping
out is neither drinking water nor fresh water
from the spring. To a great extent, itś
wastewater from treatment plants. In the Rhein river, it is about
50%, 80% in the Neckar river and sometimes close to a
100% in smaller streams. Wastewater flowing in streams
and seeping into groundwater obviously poses
a risk to quality. Testing the chemical
composition of the water samples from Hanover led to some
equally disturbing findings. Infiltration by unwanted
substances can also be found in the locations in Hanover affected
or influenced by surface water. Pharmaceuticals,
for example. So far the concentration is very
low, but detectable nevertheless. We are assuming this will get worse
in the coming years and decades. An American study
from earlier this year, showed that a considerable
part of the waters, especially in the West
had been contaminated. There are many pollutants
and the situation is most critical in areas where surface
irrigation is used for agriculture. A renowned hydrologist explains
the impact on America’s West Coast. I’m Jay
Famiglietti. I’m the Executive Director of The
Global Institute for Water Security at the university
of Saskatchewan. I’m a hydrologist. I havent been down there for a while
and to see how things have changed, how things have dried out
since I left California in 2018 Really incredible. Nowhere is the impact of
wastewater on nature more evident than in the Imperial
Irrigation District one of the largest agricultural
areas in North America. It’s man-made and in
the middle of a desert. We really need to get out
to these agricultural regions to really understand
their vast expanse. That’s true in the
Central Valley. It’s true in the Imperial
Irrigation District. You get out there and these fields
just stretch and stretch and stretch for miles
and miles. And that’s when you realize
that’s just how much water is being spread over the
surface to green up the desert. The Imperial Irrigation
District spreads 3.7 trillion liters of water per year in
the region. Meanwhile, 40 million local people face water
shortages and nature is drying up. The runoff of from
all the agricultural field gets channeled into rivers and is delivered to the Salton
Sea which is internally draining, which means it’s
like the Dead Sea. The runoff that goes into it is
full of fertilizers and pesticides. So, the water
itself is toxic. I don’t actually know
if it can be saved. I don’t know what it
would take to save it. The Salton Sea is the largest
freshwater lake in California. It used to be a
vacation resort. Today, very little can
live here anymore. I’m literally sitting on
what was a boat ramp. The lake is seeping
away and evaporating. The Salton Sea
has been a tragedy. As the waters have
receded itś created dust itś created dust that blows into
as far as the City of Los Angeles, creating air-quality
issues, to begin with. And then there is the
increased salinity of the water. So, you’ve got a number of
tragic issues that have arisen. Where there were once
parks and recreation facilities there are now barren
beach lands at best. I remember when I first came to
the Salton Sea a few years ago the water levels were literally
thousands of feet closer than they
are today. And itś just a
startling thing to see. Humans have consumed the
water for farming in the desert while poisoning the
water that nature needs to survive. In the long run, the
consequence of this dying nature will be a loss of
human habitat. The timescales that
we are talking about here these are decadal
scale timescales. This didn’t just
happen in a few years. This is the culmination of decades
of disregard for the environment. So, this is where we are gonna
end up in more and more places around the world and I
think our decision-makers need to see this and to
understand how we get to this point. Our competition with nature for
water is a battle for human existence. The fight has already been lost
in parts of America’s West Coast. Northern Europe is
doing comparably better, but here too the warning
signs have been ignored. If the same mistakes are not
prevented, it will affect everyone. How much drought can our ecosystem,
which is more used to moisture and water bodies, tolerate,
if the climate changes over a relatively
short period of time? What happens to the fauna
and flora, to animal and plant life? We can already observe some
implications in certain forests where there is
widespread die-offs. Such scenarios
are warning signs, showing that dramatic
changes are happening to nature. What are the consequences
of drought in Germany's forests? The bark beetle has killed trees
affected by the dry conditions, destroying large parts
of the tree population. To make matters worse, a new
disease now threatens woodlands. Wow! This almost looks
as if someone had torched it. Klaus Arzet accompanies
Nicole Burgdorf from the Bavarian State Institute
of Forestry into a forest where the sooty bark disease
is swiftly killing native maples. The spread of the
disease increased alongside the extreme heat
and drought of 2018 and 2019. The fungus enters the wood
through broken branches or wounds, grows into the wood, and
then spreads through the tree, especially in
dry conditions. When the fungus reaches the bark,
these spore deposits are formed, which you
can see here. These contain 170 million
spores per square centimeter and are then
released into the air. Incredible.
Just incredible. And itś not just
affecting individual trees. In this survey area about 80% of the
trees have developed the sooty bark disease and
nearly all have died. And nothing
can be done. Sooty bark disease:
unstoppable, devastating, both for nature
and humans. Because once the fungal
spores form on the bark, they can also infect people's
lungs — and become life-threatening. To show how the
disease spreads, scientists cut down an infected
tree where no spores have yet formed. This is a tragedy, because the
population is simply collapsing. Not in my wildest dreams
could I have imagined that a fungus could have
such a massive impact and cause such
widespread damage. The findings also come
as a surprise to Klaus Arzet and Professor
Martin Grambow, a longtime member of Germany’s
Working Group on Water. What is happening is
incredibly disturbing. This is a typical
tipping point. That is, once the forest is so damaged
that it dies, the whole system changes. Less water is
extracted from the air and everything becomes much
drier when the forest is gone. Then you are on your
way to desertification. If we use a human
analogy: You can get sick, but if you recover
everything is fine. But once you’re
dead, youŕe dead. And that is, so to speak,
the meaning of a tipping point. Something has changed
that is irreversible. The Technical University of
Munich uses high-tech equipment to objectively track
the effects in regions with progressive water scarcity,
even below the earth's surface. Like here in
Lower Franconia. This is one of two observation
points where we measure soil moisture in different
layers. As you can see, we have dug a
hole that is almost 2 meters deep. We then regularly install
sensors and this helps us to get a more complete
picture of the soil moisture. During the winter months
the soil should be very moist, but the team of
scientists are shocked when taking a closer
look at the upper layers. Itś bone dry. Really
unbelievable! The forest soil is maybe
rooted 50cm below the surface. Further down there is a
transition to the mineralized part, but that seems
quite dry. There are still some
roots down there too, but there's not much evidence
of any water or moisture. Itś not an
isolated case. The lack of water is already
a fact in Germanyś forests. Itś important for us in
the environment ministry to look at how the
precipitation is spread throughout the different
areas and environments. That is, how much
arrives and where? The rising temperatures mean trees
and plants need more and more water. But their roots are also
reaching deeper into the ground in search of the
diminishing water supply. And that has a direct
impact on our human habitats. The falling water levels can also
cause massive damage to buildings. In and around Hanover, the
effects are becoming apparent. Like in this old
upscale neighborhood. You can already see the
first signs of subsidence. This terrace is only 3 or 4 years
old but weŕe already seeing cracks. Only the shaft remains in place
because its foundations are very deep. Jens Knollman shows the damage
in the walls of his parents house to building surveyor
Jens Rohmann. The soil below is clay and
presumably this combination of a change in water balance
and growing vegetation is shrinking the soil and creating
damages because of subsidence. Even though the house has been
standing here for 40 years or more, suddenly a whole wall
is sinking into the ground. The cracks are a threat to the overall
structural integrity of the building. The damage is even more
apparent in the basement. During dry spells like
the recent summers, the roots reach deeper and
deeper under the foundations, like in this cellar, sucking all the water from
the soil and causing it to shrink. According to lab tests, the soil volume
has decreased by up to almost 50%. These are artificial levels
that are generated with tests, but they show that if the
soil shrinks by as little as 10%, the damage will be clearly visible
through cracks in the building. This is the exact spot we
could see from the outside. You could basically
fit your hand in there. Sinking groundwater —
even our homes are at risk. It's just sticking
out like this. Exactly. The whole house is
sagging here, sinking into the ground. And here you can see how the
wall has completely cracked open. You wouldnt expect lack of
water to be a problem in Germany. But I think several
factors are combining and causing this type
of subsidence damage, particularly in
the dry summers. I want to preserve
this house. My parents built it and my father
actually drew up the floor plans. That's why we're going to make
an investment shoring up this wall to keep it standing
for the next 50 years. Subsidence due to
sinking groundwater may still be a relatively unknown
phenomenon in Germany. But in the affluent
neighborhoods of Mexico City, excessive water use is commonplace
even though subsidence damage is equally commonplace in
this metropolis of 20 million. Jacobo Espinoza of
the city's water authority is responsible for recording the
damage, but he can’t keep up. Here you can see the cracks caused
by the subsidence of the bridge. One part of the bridge is
stable and the other is sinking. It stops here. It sinks
some 30cm each year. Graves are being
swallowed by the ground in the cemetery in
the historic old town. From here to the corner, you
can clearly see the difference. Itś almost
2.5 meters. Itś massive. First cracks, then
subsidence, all over the city. We didnt know why
the ground was sinking, but then we were told that it
was because of the excessive use of groundwater
in this area. Mexico City consumes
tremendous amounts of water, and scientist Luis Zambrano researches
the megalopolis’ water consumption. It's a challenge, an
enormous challenge. To supply water to Mexico City, a city of 20 million
people, is a difficult task. Mexico City was built
where there used to be lakes and most of the cityś drinking
water comes from the ground. Until 10 years ago,
we knew very little about the amount of
water in the aquifers. And we still dont
know for certain, since there is very little
public information about this. What we do know is
that more and more water is being extracted by
drilling deeper and deeper. Despite officials not really knowing how much water the
region actually has, here, in Valle de Mexico,
the public waterworks keep pumping up water to
somehow meet the enormous demand. In the basin of the Valle de Mexico
there is a 300% overuse of water. That is, the difference between what
is available, for example underground, and what we
are pumping out. Weŕe using three times more
water than is being recreated. The aquifers will
never be replenished. How long can
that be sustained? Increasing subsidence of the ground may
only be a precursor to what will come. And here you can see subsidence
that has occurred in recent years, due to the
excessive water use. There are hundreds of wells
here, drawing water day and night. The Chalco neighborhood, in
the middle of the country's capital, has become
uninhabitable. This part that is volcanic soil
doesnt sink because it's pure rock. And this is where
the clay soil starts, in what used to be the lake of Chalco. Over hundreds or
thousands of years it accumulated clay and
this soil is now shrinking. When you overuse an aquifer,
you leave a hole in the ground. The pressure of the soil itself
and the weight of the buildings then cause the
ground to sink. That's why we have subsidence
of 30cm per year here, and up to 40cm per year in
parts of the lake down there. So here, where we are now,
we already have subsidence of up to 15m compared
to previous years. That's where
we're at. The neighborhoods below Chalco,
Valle de Chalco and Ixtapaluca, also have more or
less this subsidence, but here it is
most obvious. 30 to 40cm is a lot! Itś
something like this — annually! And what weŕe seeing
in the center of the city you can see for yourself if you stand
down by The Angel of Independence. There are new steps, and only
the darker steps are original. All the others
are new. The reason is
that Mexico City is sinking because
of its water extraction. By the cityś famous Angel
of Independence landmark, the new steps highlight
the sinking street level. Millions of people are
already directly affected by the consequences of the subsidence,
as underground water pipes burst and break under
the weight of the city. In some neighborhoods, water
no longer comes out of the tap, turning it into a costly commodity. This family has been waiting half a
day for the delivery of their "pipa", the local
water truck. Weve been here since 9 this morning,
waiting for the tanker to arrive. Private roof water tanks
can be seen everywhere. Many people are without water
and their numbers are growing. Not only on
our street. In the whole city.
The whole city is dry. Thousands of mostly private water
trucks drive through the streets, day and night, selling
to those who can afford it. Subsidence is endangering
homes and destroyed pipes are disrupting the city's
drinking water supply. Ive been to many meetings
at the mayor's office. It showed me very
clearly that the government is not doing
anything for us here. Itś getting worse
everywhere. Itś not just this municipality
that is lacking water. They send a tanker
or two here and there. But to supply a whole
town like that, well, it's crazy Ive been without running
water for 2 years. The tanker only
comes by once a week. A while ago the neighbors teamed
up to pay for extra water deliveries from a private
company. In the beginning, the
delivery cost 800 pesos. Now it’s between
1350 and 1400 pesos. So, it's almost doubled, and
we can't afford it anymore. The people of Mexico City
have to help themselves. But the overuse
of groundwater in the middle of one of the
most active earthquake zones in the world poses
an even greater threat. When aquifers dry up, the
ground has less stability. And then, when there is an
earthquake, it can be much stronger, much more violent than
what we might expect if the aquifer would
be more or less full. What the continued overuse of
the city's groundwater resources could mean for the millions of
people is only just beginning to show. Like everywhere in nature, one thing
is clear: Everything is connected. The hydrological catastrophe
we are undoubtedly heading for will
be a huge struggle. We should immediately begin to steer
everything toward sustainability. Itś not being talked about, but
we need immediate political action. If we do nothing, we will
have massive problems. Although itś still not too late to
halt the devastating climate crisis, we continue to destroy natural
wonders for our water extraction, like here
in the US, where the mighty Colorado river
flows through the Grand Canyon. We are having such an impact
that we could kill the Colorado River and end this down-cutting that has
been going on for 70 million years very naturally —
we could end it. This is not
politics. This is just
opening our eyes. We’re observing
what’s out here. We’re doing this. And we need to be
accountable for it. These are
the images that show our responsibility
towards nature and future generations. This era is called
the Anthropocene. And it is recording the wide-spread
disregard for the environment, the massive injection of greenhouse
gases, carbon dioxide, methane, other dangerous gases
into the atmosphere. And whoever is around,
whether it’s humans or something else in a couple of
million years when they look back, they’re gonna ask the question: What
the heck were these people thinking? Did they wipe
themselves out? Maybe they’re gonna
think that their brains that our brains — weren’t as
evolved as they should be. Because obviously we are in a pathway,
on a trajectory for self-destruction.
