Cattai Creek Subcatchment

Little Cattai Creek is included in this subcatchment but is not a tributary to Cattai Creek having a distinct hydrological catchment.

The headwaters and upper reaches of Little Cattai Creek are in near intact condition and Little Cattai Creek is considered to be the most aquatically biodiverse creek in Western Sydney. The clean water contributed to the Hawkesbury River from Little Cattai Creek is extremely important to the health of the Hawkesbury River.

Cattai and O'Haras Creeks are being degraded by increased sedimentation as a result of the upstream urbanisation. Water quality is poor due to stormwater and Sewage Treatment Plant discharges into these major creeks. Woody weeds, including privet and willows, in the riparian zone pose a serious threat to patches of relatively healthy vegetation. 

The hydrology of this subcatchment has been greatly altered due to increased urbanisation and changes to catchment surfaces. This has altered channel form and function and is limiting the potential for recovery. O'Haras Creek was previously a Chain of Ponds that has been transformed by hydrological changes and channel engineering.

Significant community based environment activity is occurring on Cattai Creek with a local Landcare group involved in a privet education and eradication project. A large-scale willow eradication project has also been undertaken on the creek.