Bega River

Physical characteristics

Latitude (ºS)-36.70
Longitude (ºE)149.98
Catchment area (km2)11934.8
Estuary area (km2)1,23.8
Estuary volume (ML)36370.8
Average depth (m)41.9
Roy et al. (2001) classification5III/5/D
Entrance condition6I/O
  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:     20m upstream from Hancock Bridge on 30/11/05

Tide stateFlow
(106 m3
tidal range (m)
Sydney Harbour
tidal range (m)
Ebb flow0.870.261.37
Flood flow 1.40.311.28

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
Nov 2005 to Feb 2006Data collection: water levels at four sites; velocities at one site; water quality profiles at fourteen sites; in-situ water quality at two sites.1988-56.pdfMHL1460

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
54625s01.pdfIndex plan & cross section locations1:100001059.3kb
54625s02.pdfBega River & Mogareeka Inlet1:1000392.6kb
54625s03.pdfBega River & Mogareeka Inlet1:1000638.7kb
54625s04.pdfEntrance area, foreshore & offshore1:1000490.7kb
54625s05.pdfMogareeka Inlet southern arm (Tathra Golf Course)1:1000302.1kb
54625s06.pdfBlack Ada Swamp (southern end)1:1000302.8kb
54625s07.pdfBega River, Chinnock Lagoon & Black Ada Swamp1:2000751.5kb
54625s08.pdfBega River, Blackfellows Lagoon & Zecks Lagoon1:2000270.5kb
54625s09.pdfBega River, Blackfellows Lagoon & Humbug Reach1:2000297.5kb
54625s10.pdfCross sections - Bega River (to Bottleneck Beach)1:1000 H 1:200 V134.1kb
54625s11.pdfCross sections - Bega River & Jellat Jellat Creek1:1000 H 1:200 V158.7kb
54625.txtBega River xyz dataN/A443.2kb
Page last updated: 26 April 2012