Environmental issues

Water

Brisbane Water

Physical characteristics

Entrance
location
Latitude (ºS)-33.52
Longitude (ºE)151.33
Catchment area (km2)1152.5
Estuary area (km2)1,228.3
Estuary volume (ML)384198.7
Average depth (m)43.1
Roy et al. (2001) classification5III/5/A
Entrance condition6O
Notes:
  1. Derived from DECCW (2010) NSW estuaries and coastal catchments spatial database.
  2. Includes area mapped as open water (see note 1), mangrove and saltmarsh areas (Creese R. G., Glasby T. M., West G. and Gallen C. (2009) Mapping the habitats of NSW estuaries. Industry & Investment NSW Fisheries Final Report Series 113. Port Stephens, NSW, Australia.
  3. Based on areas at 0.6 m AHD (Roper T., Creese B., Scanes P., Stephens K., Williams R., Dela-Cruz J., Coade G. and Coates B. (2011) Assessing the condition of estuaries and coastal lake ecosystems in NSW. Office of Environment and Heritage, Sydney).
  4. Estimated by dividing the total volume at 0.6 m AHD by the total surface area of the estuary including mangrove areas but excluding saltmarsh (Roper et al., 2011)
  5. Estuary group: I = oceanic embayment, II = tide dominated estuary, III = wave dominated estuary, IV = intermittently closed estuary V = freshwater bodies
    Estuary type: 1 = ocean embayments, 3 = drowned valley estuary, 5 = barrier estuary, 6 = barrier lagoon, 7 = interbarrier estuary, 8 = saline coastal lagoon, 9 = small coastal creeks, 11 = brackish barrier lake. Evolution stage: A=youthful, B=intermediate, C=semi-mature, D=mature.
    (P. S. Roy, R. J. Williams, A. R. Jones, I. Yassini, P. J. Gibbs, B. Coates, R. J. West, P. R. Scanes, J. P. Hudson and S. Nichol (2001) Structure and Function of South-east Australian Estuaries. Estuarine, Coastal and Shelf Science 53, 351-384)
  6. Entrance conditions: O = open, T = trained, I = intermittent.

Tidal prism

The volume of water moving past a fixed cross section during each flood tide or ebb tide (i.e. slack water to slack water), is referred to as the tidal prism of an estuary.

The following table shows the measured tidal prism at the location specified, along with the tidal range for near the measurement site and at Sydney Harbour.

Location:     the entrance on 3/5/89

Tide stateFlow
(106 m3
Local
tidal range (m)
Sydney Harbour
tidal range (m)
Ebb flow25.81.261.36
Flood flow 21.31.421.49

Tidal survey

Tidal surveys measure the hydrodynamic behaviour of an estuary during a full tidal cycle. The parameters measured include velocity, water levels, salinity, temperature and pH.

The following tidal surveys have been undertaken on this estuary. A map shows the location and plots of the flows and water levels for the most comprehensive survey.

Copies of tidal survey reports are available from the Estuary Management Program

DateData collectedFigureReport
Feb 1985St Huberts Island current metering over an ebb cycle at four lines, tideboards at three locations, temperature/salinity, dissolved oxygen readings, bed and suspended sediments.-MHL444
May 1989Current metering at three lines with temp/salinity and drogue tracking.-MHL568
Feb to Apr 2004Extensive data collection: water levels at eleven sites; velocities at nine sites; and water quality profiles at thirty-six sites.1988-32.pdfMHL1319

Hydrographic survey

The hydrographic survey provides the depth and physical characteristics of the estuary.

The metadata associated with the survey can be found on the map sheets provided.

Map sheet number DescriptionScale    Size
51018sh1.pdfIndex plan1:10000616.8kb
51018sh2.pdfBrisbane Water & The Broadwater1:5000300.1kb
51018sh3.pdfBrisbane Water & Caroline Bay1:5000269.3kb
51018sh4.pdfCockle Channel & The Cockle Broadwater1:5000258.1kb
51018sh5.pdfThe Rip (St Huberts Island)1:5000459.0kb
51018sh6.pdfBrisbane Water (Saratoga)1:5000276.8kb
51018.txtxyz dataN/A364.8kb
54763s01.pdfFagans Bay1:2000382.9kb
54774s01.pdfWoy Woy Bay & Inlet1:4000810.1kb
54763.txtFagans Bay & Woy Woy Bay xyz dataN/A220.9kb
Page last updated: 26 April 2012