Challenging river diversion for the Laja 1 scheme, Chile

A five-stage river diversion process for the Laja I scheme in Chile presented some particular challenges for the project: at each stage the diversion works had to be capable of safely passing a 20-year flood. The design of the diversion scheme had an impact on the design of other structures, and was critical for the schedule of the overall scheme. Laja 1 is now nearing completion, with reservoir impounding due to begin in March 2012. This paper looks at the reasons for the unusual river diversion concept, and the challenges, which have been successfully overcome.