Maiden said the council asked Waste Management to keep staff up to date with plans to address the issues.
"Between 2014 and 2017, Waste Management advised council staff a number of times that they were working on a suitable solution to the problem, and council staff, in turn, briefed elected members on these discussions," she said.
In September last year, Waste Management told the council it would be ceasing kerbside glass collections - embargoed information that would be publically announced two months later, in November.
The company also initiated Bins for Better Communities, where groups and businesses could volunteer to host colour-sorted glass recycling bins.
Waste Management lower North Island manager David Howie said the solution had the "best recycling outcomes".
"We are pleased with the improvements to date."
Last week he said the system had increased glass collected by 25 per cent.
He did not comment on a question about what other solutions were considered.
Maiden said council staff were talking about ways to reduce waste to landfill with elected members in 2016 and 2017 before they had wind of Waste Management's plan.
Waste audits in those years found about 4.5 per cent of the kerbside waste the city sent to landfill was glass.
The first action on glass recycling came after Waste Management's embargoed announcement in September.
The council nearly doubled the capacity of glass storage bays and expanded recycling drop-off areas at Te Maunga transfer station.
She said the council did not realise until early 2018 the community glass collection system was going to be "limited in scale".
"Large parts of the city would not have a convenient location for glass disposal."
On March 7 the council voted to propose introducing rates-funded kerbside glass service in August/September - an idea the council is seeking public feedback on.
It has also proposed making all the city rubbish and recycling collections rates-funded by 2021.
