Yeramba Lagoon is a 7-hectare man-made body of freshwater that overflows into Georges River in south-west Sydney.
Whilst the Lagoon started as a Mangrove- lined saltwater estuary, Bankstown City Council filled the mouth of the estuary in 1964 and constructed a concrete weir to impound fresh water.
Since its creation, the Lagoon has become infested with many introduced species such as Water Lillies, Alligator Weed, Water Hyacinth, Yellow Water Lily and, particularly the aggressive aquatic weeds Ludwigia peruviana (Primrose Willow) and Salvinia molesta(Salvinia). These weeds have established densely matted roots which extend from the surface to approximately 400mm deep. They can clog waterways and attach their seed to flowing water, clothing, bird feather, hair, and machinery.
Weeds were controlled by foliar spray on an annual basis until funding was discontinued in 2012.
Whilst a long-term solution to the infestation is currently being investigated, in October 2017 Southern Habitat was contracted by NPWS to treat the aggressive high-risk aquatic weed Ludwigia peruviana (Primrose Willow) within nominated sections of the Lagoon.