Clarence River
Physical characteristics
Entrance
location | Latitude (ºS) | -29.43 |
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| Longitude (ºE) | 153.37 |
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| Catchment area (km2)1 | 22055.1 |
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| Estuary area (km2)1,2 | 132.3 |
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| Estuary volume (ML)3 | 283001.3 |
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| Average depth (m)4 | 2.2 |
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| Roy et al. (2001) classification5 | III/5/D |
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| Entrance condition6 | O/T |
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Notes:
- Derived from DECCW (2010) NSW estuaries and coastal catchments spatial database.
- 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.
- 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).
- 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)
- 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)
- Entrance conditions: O = open, T = trained, I = intermittent.
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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 state | Flow
(106 m3) | Local
tidal range (m) | Sydney Harbour
tidal range (m) |
|---|
| Ebb flow | 39.72 | 1.21 | 1.33 |
| Flood flow | 41.34 | 1.27 | 1.37 |
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.
| Date | Data collected | Figure | Report |
|---|
| Aug 1977 | Current metering at five lines near the entrance: - velocities, discharges, six tideboards, temperature and salinity, cross sections, sediment samples, bed samples and photographs. | - | MHL265 |
| May 1979 | Current metering at seven lines. | - | MHL384 |
| Mar 1984 | Current metering at two lines (Yamba and Maclean), fifteen tideboards, suspended sediment sampling and temperature and salinity readings. | - | MHL418 |
| Nov 1996 | Extensive 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.pdf | MHL798 |
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.
Page last updated: 26 April 2012
