The council announced yesterday it would finally act on discussion about the issue that has been regularly bandied about in meetings and agendas over the past decade.
From today, the toilets, which are staffed by an attendant, will operate 24 hours a day, rather than their current 8.30am to 8.30pm hours.
Council city property manager Kevin Taylor said there had been a lot of discussion by councillors, staff and the community about how and where to provide public toilets that would be open all day.
"It is clear there is a need for 24-hour access in the central city, and we are pleased to be able to come up with a solution.
"Feedback from the public showed residents felt the Municipal Lane facilities were clean, comfortable and safe, so it makes sense to extend a valued existing service.''
Security arrangements had been installed, including improved lighting and better CCTV coverage of the lane.
Mr Taylor said attendants would be in place at all times.
From 10pm to 6am, entry would be controlled.
The door would be locked and people allowed in only one at a time.
"Our principal clients at that hour of day may be less than savoury,'' he said, and the controlled entry would help for security and safety reasons.
"If a bunch of them turn up, the guy can just manage the situation.
"It's not that people are going to be denied, it's just managing it.''
The overnight attendant, a contractor, was trained as a security guard.
The extended hours would be covered by existing DCC staff and the contractor.
Mr Taylor said that after winter, there would be a review of how successful the extended hours had been to decide whether 24-hour access was required from June to August.
If the toilets were underused, cutting back to Thursday, Friday and Saturday nights during that period might be considered.
"Having put something new in place, we just need to review it next spring just to see how it's running.''
However, the toilets would definitely stay open 24 hours a day the rest of the time.
As well as providing toilets, the Municipal Lane facilities could also store backpacks and parcels for the day for $1, and attendants could provide information for visitors to the city.
Mr Taylor said the extra $54,000 annual cost was considerably cheaper than the cost of building and running a separate toilet complex in the Octagon.
