Yeramba Lagoon Ludwidgia Control Project
Yeramba Lagoon Ludwidgia Control Project, Picnic Point
NSW Office of Environment & Heritage (National Parks & Wildlife Service) Waterways Rehabilitation
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.
Qualified Southern Habitat staff treated the Ludwigia peruviana by applying using a biactive glyphosate herbicide approved for use in waterways. Strict hygiene protocols were observed to stop high-risk weed transfer amongst sites.
Whilst we were able to use a High-Volume Sprayer along some edges of the lagoon, we attempted to treat the majority of the Ludwigiaby poling a canoe across the water surface and spot spraying using backpacks.
All infested areas treated were recorded on a map and on PWIS Weed Treatment Field Data Sheet.