[2] The shallow waters limited opportunities for trade, forcing cargo to be loaded and unloaded at the end of the Swan River, near Fremantle.

[5][6] Work began in 1872,[4][5] using convict labour,[4] on the dredging of a path between The Narrows and the William Street jetty, to allow the passage of cargo.

[4][5] The dredge was also used around Fremantle several times, to remove sand banks and to assist boats travelling to the jetty at Pier Street.

Subsequently, the equipment used on the project, including the Black Swan was taken out beyond Fremantle Harbour's North Mole and sunk.

[11] Increasing the depth of the river put much of the swans' aquatic plant food supply out of reach, resulting in loss of habitat.

[10] In 2000, the state government released a plan to combat the decrease in black swan numbers due to dredging and other river modification, through habitat rehabilitation and recreation.