Alva St, which runs between High and Stafford Sts, has been closed to vehicles except those owned by residents since early this year, and the work originally expected to be complete on May 9 is now set to finish at the end of June.
Water and sewage pipes are being replaced and the Dunedin City Council says other streets in older parts of the city could be due for similar work.
Acting water and waste group manager Chris Henderson said because of the state of the pipes, it was decided to ''do everything while we were there''.
''It's true to say that in the older parts of Dunedin there is a lot of renewal work that definitely needs to be done.''
The job in Alva St was complicated by the land being used as a dump in the early days of Dunedin. More preparation had to be done as the infrastructure was not going though compact soil.
''You just don't know what the heck's going to be in there.''
Mr Henderson said the contract for the street was part of a package of work awarded to Downer following an open tender process.
The work also included the extension of water and waste water services in Wren Lane in St Leonards, which was completed in February.
A new water main was installed and properties transferred in early April.
Workers were now replacing an aged foul sewer which was in poor condition, particularly the lower section through the former landfill site
Additional work had been required to repair collapsed private sewers as the renewal work progressed up the hill.
It was expected the work would be completed by the end of June, subject to favourable weather and ground conditions.
The project's budget was $485,614, though it was expected to be delivered below budget.
