Koo Wee Rup Swamp

The Koo Wee Rup Swamp was an area north of Western Port Bay. Its western limit was in the vicinity of Tooradin and its easterly limit was Bunyip and the Lang Lang River. The Gippsland (Oakleigh to Bunyip) railway line marked the northern edge. Estimates of its area vary, but it was about 400 sq km.

There was pastoral settlement around the swamp in the late 1840s. A large landowner, William Lyall, had holdings at Tooradin and at Yallock, a slightly elevated area at the east of the swamp. He attempted a private drainage scheme at Yallock. In 1875 land was sold in the west of the swamp and the Koo-Wee-Rup Swamp Drainage Committee was formed by local landowners, to drain water from Cardinia Creek into Western Port Bay. Heavy rain in 1891, coming from the Gembrook Ranges by the Toomuc, Bunyip and Tarago Rivers, inundated the swamp and its reclaimed western sector. Successful drainage required a scheme for all of the swamp.

The soils of the swamp were found to be particularly fertile for crops and dairying. During the early 1890s the Victorian Public Works Department’s Carlo Catani supervised the Great Southern Railway across the swamp from Tooradin to Loch. Village settlements housed construction workers and creameries were opened at Iona (1897) and elsewhere. Soldier- settler farms were taken up during the 1920s.

Floods in 1911 and 1934 required the enlargement of drains and construction of additional outfalls. Clearing of land at the headwaters has caused increased run-off, and floodwater detritus that banks up where stream velocities falter causes flooding unless removed. Improvements and maintenance are therefore continual. Moving from west to east there are drains into Western Port Bay at Sawtell Inlet (Tooradin), at 4 km eastwards for the Toomuc, Cardinia and Deep Creeks, at 2 km further eastwards for the Bunyip and Tarago Rivers (the main drain), and at the Yallock Creek.

Despite the drainage improvements there is occasional flooding. In February 2011 Koo Wee Rup, Iona, Cora Lynn and Bayles were evacuated because the Lower Bunyip River overflowed.

Numerous small and medium-size towns have been established in the former swamp. The largest town is Koo Wee Rup. Smaller places include Bayles, Catani, Cora Lynn, Dalmore and Yannathan.

Potato growing has diversified into other vegetables as the fringe of metropolitan Melbourne has come closer. By the 1930s Koo Wee Rup and Dalmore were major asparagus-growing areas, and by the early 2000s the former swamp produced 95% of Australia’s asparagus. Market gardens draw water from the drains and from the ground by bores, but some areas have suffered from excessive take-off, with a consequent risk of mineralisation and salting of the water.