The construction of the La Breña dam (Breña II) involves the installation, at a distance of less than 160 m from the foot of the dam wall, of an electrical substation and a pumping and turbine station, which will enable water from the Guadalquivir to be pumped to the dam, thereby regulating its flow and allowing for more efficient use. The approved project involves over-excavating the riverbed to create a negative gradient that channels the flow to the pumping station. This station must be situated at a sufficiently lower level than the river channel to ensure that the pumps remain submerged; for this reason, significant excavation works are required, reaching heights of over 20 m. The aim of the geological and geotechnical works was to carry out a stability analysis of the excavation slopes involved in the planned works, and to propose a set of necessary support measures to achieve acceptable medium- and long-term stability conditions in line with the safety factors required for this type of project.
