South Creek’s 620-square kilometre catchment area flows through the Hawkesbury and seven other local government areas in Western Sydney. It has been the focus of an extensive federally-funded research by the University of Western Sydney and the Cooperative Research Centre for Irrigation since it begun in 2006.

UWS researcher Bruce Simmons and UWS Professor Basant Maheshwari spoke with The Gazette last week about their concerns on the “very poor ecology” and rapid degradation of the catchment area, a major tributary of the Nepean-Hawkesbury River.

“Siltation and erosion are quite acceptable phenomena but South Creek has dangerous nutrients such as nitrogen and phosporous that come from a variety of sources such as sewage, effluent and run-offs from urban domestic households and farms,” Mr Simmons said.

“South Creek in itself has a very poor ecology. The water is very turbid and this is one of the reasons why the entire riparian zones are degraded.”

Only on their second year of the South Creek research due for completion in 2010, Mr Simmons and Mr Maheshwari highlighted that high amounts of phosporous and nitro-gen aided the outbreak of salvinia in the Hawkesbury River in 2004.

Salvinia Molesta, one of the worst aquatic weeds, destroyed some 88 kilometres of the river and this single outbreak, largely brought by the drought, cost both the State and Federal governments a whopping $1.6 million in clean-up costs.

Water and catchment management authorities are continuously monitoring the river to eradicate remnants of the salvinia, and prevent another outbreak by co-ordinating with stakeholders and landowners along the riverbank.

Mr Simmons said their research team attended last week’s successful summit on the Hawkesbury River and praised the timely efforts of the Hawkesbury Council and other local councils tapping the river and NSW agencies to reverse the river’s declining health.