Baseline physio-chemical characteristics of Sydney estuary water under quiescent conditions.

ABSTRACT

The current study establishes baseline water quality properties for Sydney estuary, Australia for long periods of quiescence, which characterize the region. The study was undertaken in response to numerous requests for such data by researchers, government agencies and contractors. During quiescent periods, the range in Secchi depth transparency, turbidity, salinity and total suspended solid (TSS) values was 0.3-5.3 m, 18.6-0.1 NTU, 26.4-35.3 PSU and 8.3-1.0 mg/L in the upper and lower estuary, respectively. Baseline particulate metal concentrations were high, however TSS metal mass was greater during high rainfall. Tables and GIS-based maps allow baseline physio-chemical values to be extracted from the database for any location in Sydney estuary for quiescent conditions. Strong inter-parameter baseline relationships enable interpolation between water quality data. Baseline physio-chemical values were used to assess the impact of a high-precipitation event to demonstrate the utility of the new database.