Environmental issues

Water

Clarence River

Physical characteristics

Entrance
location
Latitude (ºS)-29.43
Longitude (ºE)153.37
Catchment area (km2)122055.1
Estuary area (km2)1,2132.3
Estuary volume (ML)3283001.3
Average depth (m)42.2
Roy et al. (2001) classification5III/5/D
Entrance condition6O/T
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:     450m upstream from the end of the breakwaters on 24/10/96

Tide stateFlow
(106 m3
Local
tidal range (m)
Sydney Harbour
tidal range (m)
Ebb flow39.721.211.33
Flood flow 41.341.271.37

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
Aug 1977Current metering at five lines near the entrance: - velocities, discharges, six tideboards, temperature and salinity, cross sections, sediment samples, bed samples and photographs.-MHL265
May 1979Current metering at seven lines.-MHL384
Mar 1984Current metering at two lines (Yamba and Maclean), fifteen tideboards, suspended sediment sampling and temperature and salinity readings.-MHL418
Nov 1996Extensive data collection: water levels at seventeen sites, velocities at eleven sites, in situ water quality at nine sites and 124 water quality profiles.1988-07.pdfMHL798

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
56196s01.pdfIndex plan1:4000383.3kb
56196s02.pdfLower Clarence River1:20001264.1kb
56196s03.pdfClarence River entrance1:2000446.7kb
56196s04.pdfLower Clarence River1:20001253.8kb
56196s05.pdfClarence River entrance1:20001166.4kb
56196s06.pdfCross section location plan1:2000224.6kb
56196s07.pdfCross section location plan1:2000267.3kb
56196s08.pdfCross sections - Middle wall1:1000 H 1:200 V234.0kb
56196s09.pdfCross sections - Middle wall1:1000 H 1:200 V221.6kb
56196s10.pdfCross sections - Middle wall1:1000 H 1:200 V225.5kb
56196s11.pdfCross sections - Middle wall1:1000 H 1:200 V272.2kb
56196s12.pdfCross sections - Middle wall1:1000 H 1:200 V276.5kb
56196s13.pdfCross sections - Middle wall1:1000 H 1:200 V167.1kb
56196s14.pdfCross sections - Middle wall radial sections1:1000 H 1:200 V251.7kb
56196s15.pdfCross sections - Whiting Beach sections1:1000 H 1:200 V319.8kb
56196s16.pdfCross sections - Middle wall longsection1:1000 H 1:200 V247.9kb
56196.txtClarence River xyz dataN/A401.3kb
54732s01.pdfClarence River entrance1:2000895.4kb
54732s02.pdfClarence River entrance1:1000173.1kb
54732_Channel.txtClarence River channel xyz dataN/A28.2kb
54732_Entrance.txtClarence River entrance xyz dataN/A341.1kb
Page last updated: 26 April 2012