The line between Llandudno Junction and Blaenau Ffestniog was closed on 16th March 2019 due significant flooding caused by Storm Gareth.
Detailed inspections have revealed that six miles of track, two stations and eight level crossings require significant repair.
Engineers now developed a programme of work that should see the line reopen this summer and teams have been setting up worksites and sourcing the machinery and materials needed for the repairs to restore the track. Materials required include more than 2,000 tonnes of ballast.
Bill Kelly, route managing director for Network Rail, Wales & Borders, said: “We recognise the importance of this railway, and I have seen for myself the devastation the damage has caused in the local area. We expect to open the line between Llandudno and Llanrwst in time for the National Eisteddfod taking place this summer.”