The Florence tunnel boring machine stuck underground at the Snowy 2.0 construction project in NSW has made “bugger all” progress since it was commissioned in March last year, but Snowy Hydro chief executive Dennis Barnes remains hopeful the huge machine will resume its three-year job within weeks.

Speaking a day after Snowy announced a cost blowout to $12 billion for the Snowy 2.0 pumped hydro project, Mr Barnes said on Friday that Snowy would lodge a modification to its environmental impact approval to the NSW Department of Planning and Environment next week to allow work to restart.