Revised plans for Dunedin’s waterfront, which aim to reduce costs, have been fleshed out in technical documents released by the Ministry of Business, Innovation and Employment.

The documents detail some of the compromises — including a staged approach to key parts of the project — while other features remain, including "iconic" buildings and the pedestrian bridge, public spaces, a ferry terminal and possibly even a playground.

But the paperwork also highlighted the challenges still to overcome, including traffic in an area that could result in a roading shake-up, including removing one of the Jetty St Bridge’s ramps.

All of the timber wharves around Steamer Basin also needed to be replaced — work to be paid for by the Provincial Growth Fund.

Once building began, concrete piles up to 50m deep might be needed — twice as deep as used for Forsyth Barr Stadium.

Most of the 13 documents released this week were prepared by Beca to support Dunedin’s bid for PGF money.

They detailed issues of commercial feasibility, design and the technical challenges and risks associated with the project, although some key details — including all mention of capital costs — were redacted.

One report detailed a "value management workshop" held in late 2018 to find ways to make the waterfront concept more commercially viable.

Plans for the cockleshell-shaped cultural centre in the Harbour Basin have been deferred.

That resulted in key changes, from reducing the number of access points to the water, to a staged approach to individual buildings and the wider development.

Staging also meant land earmarked for later stages would be put to other temporary uses in the meantime, the Beca report said.

Once building began, concrete piles up to 50m deep might be needed — twice as deep as used for Forsyth Barr Stadium.

One example was the option of developing a playground just back from the Steamer Basin cross-wharf, where the proposed eco-tourism centre building would eventually be built.

The waka building on the southern side of the basin — housing exhibition space, hospitality outlets and apartments — could also be built in stages, as would the waterfront hotel.

The original concept was for a two-building hotel with space for more than 200 beds, but staging meant one building, with 70 beds, could now be built first.

• $20m for 'first stage' of waterfront plan
• Cockleshell design on ice; still part of plan
• DCC will get 'cracking'Harbour development would return millions, assessments say

That would also happen as part of stage two of the wider development, while the cockleshell-shaped cultural centre was deferred, although still able to be added later, Beca said.

A cost estimates report — largely redacted — did include a section on contingencies to cover unforeseen costs, which noted some key technical and environmental risks ahead.

That included the physical environment, but also traffic modelling, construction sequencing and consent issues.

Beca also concluded it was possible to remove the Jetty St bridge’s northern ramp and replace it with a new ramp connected closer to the centre of the bridge, which would come down closer to the rail corridor.

That would free up space for a road realignment and other land uses closer to the water, but wider traffic and safety issues, including reduced sight distances, would need to be considered.

Council staff were already working to update city traffic modelling, to incorporate the impact of the waterfront plan and other developments, which was expected to be finished soon.

The community would then be consulted on potential transport changes and other options for the area, staff said.

That would include "comprehensive engagement" with the community, towards the middle of the year, to gauge "what people want to see in the public spaces".

The process would include workshops, surveys and interactive sessions, after which project partners would co-design changes "to best express the community’s aspirations", staff said.