Cr David Benson-Pope said he did not agree with Minister for the Environment David Parker that the Resource Management Act (RMA) was "broken".
He also feared dilution of local input into decision-making once the new system was in place.
The Government yesterday introduced the Natural and Built Environment Bill and Spatial Planning Bill, which will replace the unwieldy RMA.
The third piece of the reform package, the Climate Adaptation Bill, will be introduced later.
Key elements of reform include setting up 15 regional committees to lead local planning, some standardised conditions and a reduced need for consents.
Mr Parker said the new system would better protect the environment while cutting red tape, lowering costs and shortening the time it took to approve new homes and key infrastructure projects.
"On a conservative estimate, costs to users will fall by 19% a year, or $149 million, equal to more than $10 billion in cost savings over 30 years."
Cr Benson-Pope, a former Cabinet minister, said suggested savings were "a bit overblown".
He was wary of a one-size-fits-all mentality.
Dunedin had a well-thought-through plan for accommodating development where it was best for it to occur, he said.
"A lot of wheels are being reinvented now, many of them unnecessarily."
Cr Benson-Pope supported testing the new system on three regions initially and said Otago could be well placed to be involved before implementation began in other regions.
He had no issue with a fast-tracked consenting process, such as the one applied to the new Dunedin hospital.
Dunedin Mayor Jules Radich said he expected some benefits from increased standardisation.
"I welcome the improvements in efficiency that the new system will bring," Mr Radich said.
He remained concerned about the Government’s inclination for centralisation.
Terramark consultancy planning manager Darryl Sycamore saw some merit in what has been called an outcomes-based system, as this promoted a more holistic approach to planning.
Dunedin city councillor Steve Walker expected many New Zealanders would not be sorry to see the demise of the RMA.
"The RMA was designed to promote the sustainable management of natural and physical resources but at the end of the day it simply hasn’t protected the environment enough," Cr Walker said.
