A normal requirement for many open pit mines is dewatering to remove water inflow as the mine depth extends downward below the water table.
Various wells would be located around the open pit perimeter to remove water and to preclude inflows from adjacent areas.
Pressure and thermal monitoring boreholes would be used to ensure the fluid removal process was proceeding safely.
Where co-located with shallow hydrothermal reservoirs that might be over 200°C, there would be hot, pressurised fluids that as the overburden is removed the reservoir might become somewhat depressurised enough to result in a steam cap. The steam would have to be removed to depressurise the systems.
In geothermal areas, some non-reservoir water (e.g., seawater) may be required to be injected to “cool” pit walls to facilitate safe mine operations.
