The 500m long High St tram extension loop opened to great fanfare in June last year, but since the derailment trams have had to make their stops on Manchester St.
An investigation by Christchurch City Council found the incident on the $3.6 million extension was the result of "several contributing factors", which are being addressed in the upgrade.
The city council said the cost to upgrade the track is being covered under the defects liability period.
The work is being done in tandem with a $9 million upgrade of High St in an effort to make the area more attractive and people-friendly.
The upgrade is expected to be completed by the end of October in time for the busy tourist season.
-By Geoff Sloan
Public Interest Journalism funded through NZ On Air
