Part 3/7:
Over time, the initial dyke is raised by adding more layers of tailings on top. As new layers are added, the discharge point is moved accordingly, allowing for an expansion of the impoundment area. One of the advantages of the Upstream method is that it uses less material, thus reducing costs. However, it is also more susceptible to liquefaction, a condition where the soil loses strength due to seismic activity, making it a less favorable option in earthquake-prone areas like Chile, where it is banned.