The work has meant Brighton Rd has been closed to two-way traffic, and controlled by temporary traffic lights for most of the period.
The work began in July last year, after a large, deep sewerage pipe became blocked.
Water and waste services network contracts manager William Clifford said at the time water and sewage ended up on the road, and one resident had a toilet "bubbling up".
The blockage was found in a pipe running underneath Brighton Rd.
The pipe was deep and relatively large, and its location near the beach meant there were sandy conditions.
Mr Clifford said last week the work had required installation of a wastewater storage chamber, which took longer than planned because groundwater levels were higher and ground conditions poorer than originally expected.
The installation was nearly done.
Design changes were also required to provide a solid foundation for the new chamber.
Mr Clifford said the bulk of the work on the pipe replacement was complete, but there was still work to do.
The replacement pipe was in place and contractors were reinstating areas where work was done.
"We were able to line nearly half of the existing pipe instead of replacing it with a new pipe.
"This saved time and money as we don't need to excavate along the length of the pipe to reline it."
Other sections of the pipe were so degraded they had to be replaced.
He said the road would be reopened to two-way traffic once the storage chamber was installed, which was expected to be done by the end of this week.
Speed restrictions would stay in place until final work was completed.
