Work to strengthen the Ross Creek Reservoir dam wall is nearing completion.
The Dunedin City Council expects the main engineering work on the dam to be completed within the next two months, before it is left to strengthen for a year.
Council planning and delivery manager Jared Oliver said the dam face had been rebuilt and work on the crest had started before a new concrete wave wall was installed.
The finished bank extended out further than the original, and provided greater stability, so more water could be kept in the dam, Mr Oliver said.
Thousands of tonnes of fill had been used in the project, he said.
''This dam strengthening project is an engineering challenge, involving a massive amount of earthworks, but will provide a valuable back-up water supply for the city in the long term.''
The refurbishment of the 150-year-old facility had to be extended by about six months because contractors needed excavate deeper than expected to remove the old embankment material.
Poor weather and an archaeological discovery had also delayed the project.
Once the engineering work had finished, the walking path along the crest would be opened, along with a new footbridge across the spillway channel.
Burma Rd would also be reopened.
The extra work meant the cost of the project had increased from $6.6million to $8.6million.
Once construction of the dam was completed the area would be landscaped and art incorporated into the restoration.
''The Ross Creek area is already a great destination for runners and walkers and getting an artist involved in the restoration will bring a creative element as well,'' Mr Oliver said.
