One ban, in August 2019, was for vaping in the library and "non-compliance to repeated requests to stop swearing, raising voice, [and] shoes on furniture".
"[It] caused customers and staff to feel unsafe and uncomfortable," according to the information released.
Mid-2019 saw a run of bans over three months. The first came in June for disorderly behaviour and threatening to punch a staff member.
The next month, another person was banned for disorderly behaviour, swearing and racial abuse directed at a security guard and safe city guardians.
Then in August, a person was banned for "angry and intimidating behaviour towards staff - raising voice, yelling derogatory comments".
In January 2020, one person was banned for an "alleged over-familiar conversation with a female library staff member" and another for attempting to break into the library on a weekend.
One person had their ban from the library extended for another two years when they breached the first ban.
Rotorua Lakes Council operations manager Jocelyn Mikaere said the safety of staff and the public was the council's "primary concern and consideration" and offensive behaviour occurred "from time to time".
"To protect the health and safety of staff, [the] council has safety procedures and processes in place. Staff receive specialist training, we use technology such as CCTV, communication devices and phone apps to report health and safety events, and have security guards available.
"Along with [these] measures ... staff are encouraged to report any concerns to their managers and or their health and safety representative."
Mikaere said managers in the area concerned made the decision to trespass in line with the council's Issuing of Trespass Notices Policy - "the focus of which is to prevent harm to any person or council-controlled property or space".
Usually this decision was made in conjunction with the police or WatchDog Security, she said.
"Although a person has no right of appeal under the Trespass Act, a trespass notice issued by [the] council can be challenged by seeking a judicial review, making a complaint to the Ombudsman or by challenging the legality of the notice."
Asked if the drop in bans between the two years was indicative of a longer trend, Mikaere said the council was "not in a position to speculate about fluctuations".
"However in some locations additional measures … have been implemented to help us identify and deter issues."
Of the 22 bans over two years, 13 did not have reasons recorded.
A council spokesperson said this was because the reason "was not recorded at the time the trespass notice was served".
WatchDog Security chief executive Brett Wilson said his company helped council staff members on about a weekly basis by removing people from council facilities or controlling situations until the police arrived.
He said the behaviour usually fell into three categories: young people - sometimes in gang colours - getting into fights; drunk or drugged people; or instances of domestic violence.
He said in one instance, at the library, a young person had a knife.
Wilson believed the library's proximity to the bus stop might account for the concentration of incidents there.
He said the incidents were a "reflection of what's going on in the wider CBD" and, in his view, the number of violent incidents across the city were increasing.
WatchDog monitored and helped with security across a number of sites, not just council facilities.
Wilson said he was "constantly" concerned about the safety of his staff as a result and was regularly reviewing operations to ensure their wellbeing.
