Catchment priorities
How do we prioritise catchment actions?
The four priority pollutants for the Sydney Catchment Authority (SCA) are:
- pathogens
- phosphorus
- nitrogen
- suspended solids.
They can come from a range of point and diffuse pollution sources including sewage treatment plants, mines, industry, and intensive livestock.
We use a Catchment Decision Support System to assess the pollution risk of each of the known pollution sources in the drinking water catchments. We then decide our priorities for action by considering:
- the pollution risk
- the effectiveness of treatment options
- the cost of treatment options
- likely factors that could influence the effectiveness of potential actions.
We concentrate our actions on the top 100 identified priorities. Each priority is defined in terms of a drainage unit location, a pollution source, and a pollutant.
In addition to taking action on known pollution sources, we also fulfil our statutory obligations to sustainably manage the land under our care and control, and assess a range of proposed developments to ensure they will not have a negative impact on water quality.
Where are our catchment priorities?
Known pollution sources are identified by land use and location. Our catchment area is divided into 27 sub-catchments which are further divided into smaller areas called drainage units. The SCA has identified drainage units where particular land uses are a priority for action.
The following map of Sydney’s drinking water catchments shows local government boundaries and sub-catchment boundaries. The map will help you to identify the sub-catchments in your local area. The information on this website about our activites lists the sub-catchments where we are currently active.
