Drilling work that reaches so deep into the ground that it can influence the movements or the nature of the groundwater is referred to as "earth excavation". If you are planning such an earth excavation for geothermal use with a vertical geothermal probe, you must apply to the responsible water authority.

Each borehole provides data for the evaluation of the subsurface at the respective location. The notification enables the responsible authorities to get an on-site impression of the drilling project and the produced drilling material. The authorities can take supplementary measurements and ensure the quality of the drilling results. This prevents costly wrong decisions in underground spatial planning.