Dewatering

The deliberate attempt to lower the ground-water level in or below land surface for selected purposes such as agricultural, construction, mining or other activities. For mining operation, dewatering usually is accomplished by pumping the water out of the ground and discharging to a surface-water body. However, some dewatering involves gravity feeding water from the surficial aquifer into a deeper aquifer through recharge wells.


Source: Corrosion-Doctors.org

Wikipedia:  https://en.wikipedia.org/wiki/Dewatering