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  • This is the town of Staufen, near the Black Forest in south-west Germany.

  • And as you walk around, it looks like a normal German town

  • with one strange addition.

  • Up on some buildings, there is a big fake piece of sticky tape

  • with a slogan that translates as "Staufen must not fall apart".

  • Unfortunately, it's a bit late for that.

  • The government here tried to bore for geothermic energy

  • and they bored, in total, seven boreholes right behind the town hall.

  • Underneath of Staufen is a big layer of anhydrite

  • and underneath that is a layer of groundwater in a confined aquifer.

  • The pressurised groundwater went into the layer of anhydrite

  • and formed gypsum which expands by about 50%.

  • Unfortunately, that means that the ground is expanding, bulging up,

  • and forming cracks in almost every single house that's standing here.

  • It took two weeks for the first cracks to appear.

  • In the decades since the drilling operation

  • the town hall has risen more than half a metre

  • and moved sideways by about the same amount.

  • And that might not sound like much, and yes, if everything

  • had shifted evenly it might not even be a problem.

  • The trouble is that different parts of each building

  • have shifted by slightly different amounts.

  • Modern buildings couldn't cope with that,

  • and that town hall was built in 1546.

  • The result is cracking.

  • There's water from this confined aquifer that's pushing up the boreholes.

  • And what they are trying to do is get the water out,

  • get the pressure down from the confined aquifer

  • so that it doesn't even want to go up those holes anymore.

  • So they are pumping at a speed of around a litre per second.

  • The swelling started with about a centimetre per month,

  • now it's down to about a millimetre per month.

  • But it's still swelling, and even a millimetre is still way too much for every house.

  • Theoretically, they can stop it,

  • but you cannot just plug it like a bathtub.

  • It's not a single plane.

  • It's more three dimensional, so in reality

  • you would need a big, big plug and you don't even know where it exactly is.

  • The drilling company settled out of court for more than €1m,

  • but the cost of the damage here is estimated at more than 50 times that.

  • And there are eight other German towns with similar problems.

  • Geothermal drilling was popular and not massively regulated.

  • And while the industry and the country have learned from those mistakes,

  • for this town that knowledge comes a little too late.

  • Thank you very much to Constantijn Crijnen,

  • he suggested this video in the first place.

  • He also has his own YouTube channel where he's building

  • a 3D printer from scratch, go check him out.

This is the town of Staufen, near the Black Forest in south-west Germany.

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