Formerly the Department of Works & Buildings, the Public Works Department expanded greatly from the beginning of the century, becoming responsible for the construction of the Goldfields Water Supply and Fremantle harbour. The Public Works Department changed its name to the Building Management Authority on 1 January 1985.

The Fremantle Harbour Trust was created under the Act of the same name in 1903. Certain functions of the Harbour and Light Department were transferred to the new body, particularly control of the pilotage service, signalmen and the Fremantle light keepers. A Board of Commissioners was responsible for carrying out the functions of the Harbour Trust as laid down by the Act. An Amendment Act in 1964 changed the name of the Trust to the fremantle Port Authority.

Under an amendment to the Fremantle Harbour Trust Act in 1964, the name of the Trust was changed to the Fremantle Port Authority.