Albion Park-based firm Coastwide Civil were announced on Thursday as the successful tenderer for stage one of works for the project.

Stage one of the $150 million boat-harbour contract works is expected to take about a year to complete. It is the first of four major contracts to be issued for the harbour's construction.

Coastwide's program of works includes major excavation to complete the first phase of the harbour's development.

Construction is expected to begin in January and the final stage of works be completed by 2020.

The boat harbour and marina, part of the final phase of the Shell Cove project, have been in the planning stages for almost 30 years.

Last November, councillors approved the marina's construction using a revised financial option in accordance with project manager Australand.

Work on the long-delayed project was put on hold indefinitely in 2008 due to slow land sales.

The $600 million development will comprise a 300-berth marina, a retail and commercial centre, a residential development of up to a thousand dwellings, a technology park, a public boat ramp and boat-servicing facilities.

Australand's NSW residential division general manager Nigel Edgar said the boat harbour was one of the most significant pieces of infrastructure to be built in coastal NSW for close to 30 years.

"As well as attracting an increased level of tourism to the area, the boat harbour will also create approximately 2670 jobs including direct, indirect and supported employment for the region," he said.

It is slightly larger than Sydney's Darling Harbour.

More than $25 million has been invested in the project to date, including retention and maintenance of the 11.5 hectare Myimbarr Wetlands.

Mayor Marianne Saliba was "elated" that a local company had won the initial contract for this "ambitious" project, considered to be the largest of its kind undertaken by a local government in Australia.

"The boat harbour and marina will be a welcome addition to the area and provide a vibrant, seaside location that will attract tourists and help diversify our economy," she said.

"Work beginning will be a welcome sight for the nearby residents.

"This is a wonderful Christmas present for the residents of Shellharbour City."

Coastwide was co-founded by long-time Kiama resident Gary Rogers.

Its projects have included the Lake Illawarra breakwater and Port Kembla's New Tug Berth Facility, where they were responsible for reclaiming around 3000 square metres of land and building an adjoining breakwater.