Plans to redevelop the derelict Toombul Shopping Centre site in north Brisbane face indefinite delays as new flood modelling reveals the "sheer size and complexity" of mitigation work required.

The site has gathered dust, mould, graffiti and complaints from residents since it was ruined by the 2022 Brisbane floods.

The developer, Mirvac, said it did not have an estimated construction start date as it was in talks with state and local governments over flood mitigation strategies.

National development director David Hogendijk told ABC Radio Brisbane the developer needed to compare Brisbane City Council's updated flood models with its own before a development application could be lodged.

He said if the process went smoothly, Mirvac hoped it could have a development application lodged with the council by the end of the year.

"We acknowledge that it has taken us longer than we had expected to get to this point, but to redevelop this much-loved site is highly complex and involves many experts as well as local planning and other authorities," Mr Hogendijk said.

"This is a detailed process that takes time, and even more so given the sheer size and complexities of the flood mitigation challenges this site presents."

Challenging task

Mr Hogendijk said Mirvac was required by Queensland law to reduce flood risks on the site without redirecting floodwater to neighbouring areas or waterways.

He said that could potentially be achieved by turning about three hectares of the site into green space.

Mr Hogendijk said Mirvac was talking with all levels of government about potential grants or funding programs which could offset the cost of the green space.

He said Mirvac was also in talks with Translink over which areas could be set aside for a bus interchange.

He said the green space and bus interchange could take up four hectares, meaning the remaining developable space could be reduced to six hectares.

Mr Hogendijk said Mirvac was in discussions with the major retailers with a view to securing an anchor tenant for the site.

However, he said Mirvac was still considering options for the master plan, which could include a mix of retail, housing and other land uses.

Mirvac said demolition works were on track to finish by late 2024 or early 2025.

Hope for the future

Nundah resident Gary Jordan said Toombul Shopping Centre used to be a convenient three-minute walk from his home.

The 75-year-old said he had resigned himself to the fact the site would likely not be redeveloped for many years.

Mr Jordan said he only hoped that when the site was redeveloped it had a place for grocery shopping.

"I think they need one of the big retailers like Coles, Woolies or Aldi."