Depending on where you drill, you might end up in a situation where some layers come into contact with high-pressure water and start swelling, resulting in raised surface levels. Most prominent example I know of, is the city of Staufen in Germany:

https://en.wikipedia.org/wiki/Staufen_im_Breisgau#Geothermal...

https://www.thelocal.de/20170818/this-historic-german-town-i...

To my limited understanding, this could have been prevented by a better geological survey.

In some locations there have been concerns about geothermal and induced earthquakes. http://www.seismo.ethz.ch/en/knowledge/things-to-know/geothe...

Only some of the geothermal tech requires injection of fluids along the lines of Fracking. The article suggests for those cases the risks are lower, due to the different pressures and fluids required. Other techniques (closed-loop systems) don't require it at all (but do require advanced drilling tech).

also fwiw, the induced seismicity from fracking was found to come from injected wastewater associated with post-frac oil production [1]. it's my understanding that the majority of these geothermal systems are injecting about as much as their pumping up, so stress doesn't build/you don't have that issue.

[1] https://www.usgs.gov/natural-hazards/earthquake-hazards/scie...