Also at Lake Eucumbene, the long Eucumbene-Tumut Haupt-tunnel diverts the flow of the Snowy River to the Tumut River, empting into Tumut Pond Reservoir; and into the Murray-Darling basin. This tunnel was constructed between November 1954 and July 1959 and along 28% of its length is lined with a circular diameter. The residual length of the tunnel in unlined and circular in diameter. Construction was through granite and metamorphosed sedimentary rock, involving the excavation of ; and concrete was used to install the pipeline.