Mr Winders said HEB Construction had been contracted to build a new "cross wharf" between the container terminal and the Beach St wharf.
It would be the last wharf to be completed as the port company ensured it had "really good modern, fit-for-purpose wharf infrastructure that’s been well maintained".
The structure to be replaced had an 1890 retaining wall, as well as 1960s and 1990s modifications.
It sat between two wharves that were in "really good nick", Mr Winders said.
"We closed this a number of years ago, before I started, and we’ve been looking at how we square this up.
"It’s just a final tidy-up in our Port Chalmers infrastructure — we called it ‘the next generation project’ in 2012.
"That was to extend the wharves and tidy it all up. This is the last leg of that," he said.
"It’s not that big a job, but it’s $7.5 million.
"You’re having to work from the water — it’s quite expensive."
Some of the hardwood from the original structure would be saved and reused as interior panelling in the new Port Otago offices under construction, he said.
Consent documents provided by the Dunedin City Council said the work involved demolishing the existing timber wharf, removing piles, stumps, decking and a seawall.
The work involved removing about 30 sqm of reclaimed land behind the existing sea wall; building a new 80m-long sea wall, including steel piles and precast concrete panels; and maintenance dredging and reshaping of the batter slope on the seabed for the berth pocket for vessels.
A report provided with the Port Otago application indicated there would be impacts on sea life near the work and mitigation measures were proposed to reduce sedimentation, and to relocate sponges that could be affected.
"The applicant considers that the effects of the works on biological communities will be minor during the temporary construction works and in time these communities will re-establish once the works have been completed."
Approvals were obtained from iwi consultancy Aukaha and the Department of Conservation, the consent decision said.
