Mayor Dave Cull lauded both the practical value of the $8.6 million, multiple award-winning Ross Creek refurbishment project, as well as the ''tremendous'' heritage and amenity value of the area, in front of a crowd of about 50.
The reservoir's dam, first opened in 1867, is a Heritage New Zealand Category 1 structure.
The well-used trails would also, by the end of next winter, be complemented by art work, designed to reflect the southern constellations.
However, the repaired infrastructure was also an important step in adding to the city's ability to withstand extreme events.
''We know that the two pipes that come across from Deep Creek and Deep Stream cross a gully together and they're very vulnerable,'' Mr Cull said. ''This is a great step forward in resilience. And increasing the resilience of our core infrastructure is increasingly important, particularly with the increasing number of extreme weather events resulting from climate change.''
The next step in securing the city's water supply was to build a pump station and pipe from the Ross Creek reservoir to the Mt Grand water treatment plant, he said. The roughly 250,000cu m of water stored at the reservoir could then be used in the event of a major storm cutting off the supply from Deep Creek and Deep Stream.
Council 3 Waters group manager Tom Dyer said the council had budgeted $2.58 million in 2021-22 for the construction of the pipe and pump to transfer water to the Mt Grand plant.
Costs had escalated on the Ross Creek project since it began - $2 million was added to the project when the Otago Regional Council consent for the project involved more work than originally thought.
The bulk of the latest added cost was due to the contractor having to dig the dam 3m deeper than anticipated to get to bed rock.
