Landscape designers have raised hope among Onehunga community leaders that beaches broken up by an undulating headland can be restored to the suburb's dilapidated waterfront within a $28 million budget.

The Onehunga Enhancement Society says all of seven concept designs submitted for an ambitious restoration project provide for 11ha of reclamation promised by the Government in the 1970s to mitigate the impact of motorway construction on the waterfront.

Auckland City staff initially estimated such a large reclamation including several beaches would cost at least $40 million, blowing a budget provided by their council and the national Transport Agency, which is duplicating Mangere Bridge and widening its motorway approaches for $230 million.

The city council, which agreed to add $10 million to a pledge of $18 million from the Transport Agency, now says it hopes to award a contract by September for a full restoration project to take until mid-2014.

That follows a decision to short-list three of the seven design and construction groups which submitted concept proposals, and to prepare a detailed design brief for them.

The brief is to be developed by a working group of representatives of the enhancement society and the Maungakiekie Community Board as well as city council and Transport Agency officials.

Enhancement society chairman Jim Jackson said the latest progress was most encouraging, after years of campaigning to persuade the agency and its predecessors to honour the Government's original commitment to rehabilitate Onehunga Bay.

Although he was not at liberty to disclose details of the submitted proposals, his group felt they all displayed "a quality outcome for this much-neglected part of Auckland".

"Two designs in particular absolutely stood out, including beaches and an undulating headland - not just some flat piece of land," he said.

Mr Jackson said that although he understood Auckland Regional Council was generally opposed in principle to reclamations, the winning contractor could be confident of community support at resource hearings for restoring and beautifying an area which had been "absolutely trashed" in the past.

Although the regional council resisted efforts to persuade it to contribute financially to the project, it was represented on a panel which evaluated the seven initial design concepts.

City communications manager Glyn Jones said restoring Onehunga's waterfront was a significant project for his council. Its allocation of $10 million represented a commitment "to delivering enhanced access to a high-quality coastal environment along the foreshore".

Although the council hoped to have the contract awarded by September, that would be subject to endorsement by the Auckland Transition Agency in the lead-up to the creation of the Super City in November.

Once a contract was awarded, the project would enter its developed design, planning and resource consenting phase, which would include public and iwi consultation.

Transport Agency northern highways manager Tommy Parker said it was too soon to tell whether the full 11ha could be reclaimed within the budget, and a final scheme would have to be signed off by his board.

But Mr Parker also disclosed that he had asked the Fletcher Construction-led consortium widening the motorway to suggest a price for replacing the old Mangere Bridge for the use of pedestrians and cyclists and for fishing.