As the pit floor deepens, the volumes of drainage become greater and it is suspected that this drainage now drains water from the river to the south.
Nagaré measures groundwater fluxes in 2 piezometers located between the river and the pit floor in order to characterise groundwater flux and improve knowledge of the hydrodynamics of the area.
Groundwater fluxes are measured both when pumping is stopped and when it is in operation.