3.1.3. Influence of the Piezometric Head Elevation

The comparison between Figures 5 and 6 shows that the volumes of non-dischargeable water were higher in the TOP scenarios. This means that expected environmental impacts on surface water bodies increased with the higher elevation of the piezometric head. Concerning the impacts on the surrounding groundwater head distribution, they would be similar with different elevations of the piezometric head. The magnitude of the produced oscillations should depend only on the value of *K* (magnitudes are proportional to *k*) but not on the initial depth of the piezometric head.

However, in the TOP scenarios, the piezometric head will oscillate systematically below the elevation of the natural piezometric head, whilst, in the MIDDLE scenarios, the piezometric head will oscillate around the natural position of the piezometric head. With regard to the impacts on the groundwater quality, they were expected to be larger when the piezometric head was lower since the magnitude of the outflow increased, which can be deduced by comparing Figures 5b and 6b, and therefore, the spreading of mine water in the surrounding medium also increased. If the piezometric head is at the top, the hydraulic head is mostly located below it, and therefore, groundwater from the aquifer tends to flow toward the mine minimizing the spreading of mine water in the surrounding medium.
