Plans to rebuild the depot at the corner of Bishop Road and Great Northern Highway date back about a decade but uncertainty over local government amalgamations caused delays.
Council voted to approve the 15 per cent design of the new building last Wednesday, meaning construction can start towards the end of the year.
The new design will be built directly north of the existing building, which will be demolished and turned into a carpark.
Drawings for the current brown-brick depot building date back to 1962.
A recent hazardous materials assessment found the building contained asbestos, synthetic mineral fibre, polychlorinated biphenyls, lead paint and ozone depleting substances.
The building also no longer complies with the Building Code of Australia in areas of fire prevention, fire escape and safety compliance. Swan staff considered several options, including relocating to another site and renovating the existing building, but all reports pointed to demolishing the old depot and replacing it with a new, purpose-built structure.
Councillor Ian Johnson, with the support of councillor Rod Henderson, proposed a motion to delay the project and reassess it in two years.
They said the project was not financially prudent in a time of economic uncertainty and would potentially result in further rate rises.
But the motion was lost 11-2, with several councillors arguing the project was already budgeted for and the City owed a duty of care to its staff.
The community safety, community transport, construction and maintenance, facility management and fleet and waste business units are based at the depot.
They will be housed in the new facility.
Once staff are relocated to the new building, the existing building will be demolished and turned into a carpark.
Space for a new civic building has also been set aside in the Midland Oval Master Plan.
However, the type of civic use has not yet been determined.