- This is the Ruhr Valley in Germany.
And it used to be a mining region.
It used to produce huge amounts of anthracite,
the sort of coal that you have to dig deep, deep tunnels to reach.
Sometimes more than a kilometre down into the ground.
But the last deep coal mine here closed at the end of 2018
as the world steadily shifts to renewables.
But you can see the legacy of that mining in the landscape, in places like this.
Strange hills which are old spoil tips.
Dumping sites for everything that was dug up, that wasn't coal.
All the earth and rock that was moved out of the way to create the mine shafts.
They're steadily being reclaimed. Trees have been planted all over.
And several of them now have art like this at the top.
I visited one art piece called the Tetrahedron yesterday.
The weather was bad and there was fog.
And honestly it felt like I was on
some sort of alien planet from a sci-fi show.
The hill I'm standing on has an amphitheatre as well,
although it's a little rundown now.
It is very, very difficult to get across the sheer scale of these on camera,
the incredible volume of earth and rock that was moved over decades.
Don't get me wrong, the Ruhr Valley is still industrial.
There are still opencast coal mines
and factories producing all sorts of things.
But it does seem like there's more and more talk about the legacy of industry here
than actual industry itself.
One old coal mine is now a museum and World Heritage Site.
There's another strange legacy of the old coal mines here, though.
If you take that much material out from under the surface and put it on top,
the mass of it starts changing the landscape
in a very different way.
Parts of this valley sank unevenly, as far as 20 metres down in places.
And that altered the way that rainwater drains.
In that: it starts to drain towards where people live.
So yesterday, I got to visit one of the pumping stations
that puts the water back where it's supposed to be.
- The problem is that we have coal mining in this area since 1850.
And because of this, the landscape has sunk down.
And so we had to pump the whole River Boye up 18 metres to the river Emscher.
And the river Emscher is flowing to the Rhine.
In my operational area, we have about 60 pump stations,
from a very small station with a few hundred litres,
to this station with 40,000 litres per second.
83 square kilometres is our operational area, this one station.
From my operational area, nearly 60% would be flooded
if the whole pump stations wouldn't work.
If you have dry conditions, it would be four to five days.
In heavy rain conditions only five hours. The water will get out.
- Just to be clear, those pumps are moving a whole river,
a small river, but a whole river, 18 metres up
and through massive underground pipes.
So the water can then join a bigger river that does eventually flow to the sea.
There are around 180 pumping stations, large and small, across this valley.
That one station is the largest.
After a heavy storm, it will move up to 40,000 litres of water every second.
If you look at articles about this,
they'll sometimes mention groundwater and aquifers.
But the engineers here told me that is wrong.
It is probably a mistranslation.
These are storm drains to deal with rainwater.
- The coal mining companies are paying for this
because they had dug the coal.
And because of this, the landscape has sunk down.
So they have to pay for.
- When coal mining started here 150 years ago,
no one thought about the land sinking.
And when they did notice it, which was somewhere around 1900,
it didn't stop the mining. They just built the first pumps.
The coal was worth the money and the trouble then.
But running the pumps is an eternal cost.
Not technically eternal, I guess.
But this won't go away in 100, or 1,000, or 10,000 years.
Not until something equally dramatic and geological comes along to reshape the land.
If people want to live in the Ruhr Valley,
not the Ruhr Swamp or the Ruhr Lake,
then the pumps must run.