Shortland Lawn in Foreshore Park could be closed until the end of the year after it was damaged by the recent Van Gogh Alive event.
The lawn has been fenced off to the public to allow for remediation works, which include returfing following damage to the grassed area from the exhibition infrastructure.
A section of the underground irrigation system was also damaged and had to be repaired.
The remediation work is expected to take four to six weeks. Pedestrians won't be able to use the space in that time.
Van Gogh Alive ran during September and October and was attended by more than 80,000 people.
A City of Newcastle spokesperson said as part of the contract and event licence, the Van Gogh Alive organiser would be liable for any costs associated with the remediation work to the site.
However the council did not respond to a question about how much the repairs were expected to cost.
Organiser Andrew Kay said "well over $100,000" was invested in additional ground protection works to minimise damage to the site due to the extensive wet weather conditions during the event period.
"Post-event site remediation of this level was not unexpected with infrastructure of this scale and was included in the contract from the outset, with these works now underway," Mr Kay said.
Newcastle East Residents Group member Christine Everingham said while she believed Van Gogh Alive was a good event, a council survey about Foreshore Park showed that shade and trees were more wanted by the community than large events.
"There needs to be somewhere ticketed events can be held which aren't going to damage the park, and stop people from using the park," she said.
"Events put it out of action for such a long time - there's the set-up and the damage after.
"Pretty much as soon as it gets repaired, Supercars comes in.
"The park is well used when there's not ticketed events.
"It's a beautiful part of town."