Wallaga Lake

Physical characteristics

Latitude (ºS)-36.37
Longitude (ºE)150.08
Catchment area (km2)1263.8
Estuary area (km2)1,29.3
Estuary volume (ML)333512.0
Average depth (m)43.7
Roy et al. (2001) classification5III/5/B
Entrance condition6O/I
  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:     1.5km from the entrance at the road bridge on 29/3/95

Tide stateFlow
(106 m3
tidal range (m)
Sydney Harbour
tidal range (m)
Ebb flow0.40.051.35
Flood flow 0.380.031.31

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
Mar 1995Water levels at ten locations, discharge at one line, water quality profiling and drogue tracking. Entrance very constricted.1988-54.pdfMHL725
Feb 1999 to Feb 2000Meads Bay Water Quality Monitoring 2000-01.-MHL1048

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
9792SH1.pdfIndex plan & cross section locations1:10000674.4kb
9792SH2.pdfWallaga Lake (Snapper Point)1:5000208.5kb
9792SH3.pdfWallaga Lake1:5000435.9kb
9792SH4.pdfWallaga Lake entrance area1:1000151.7kb
9792SH5.pdfWallaga Lake entrance area (causeway)1:1000220.4kb
9792SH6.pdfWallaga Lake entrance area1:1000120.6kb
9792SH7.pdfWallaga Lake entrance1:1000229.3kb
9792SH8.pdfWallaga Lake entrance (southern section)1:1000190.4kb
9792SH9.pdfCross sections - Meads Bay1:1000 H 1:200 V94.9kb
9792SH10.pdfCross sections - Meads Creek, Narira Creek & Black Lagoon1:1000 H 1:200 V105.4kb
9792SH11.pdfCross sections - Black Lagoon & Dignams Creek1:1000 H 1:200 V119.9kb
9792.txtWallaga Lake xyz dataN/A123.3kb
Page last updated: 27 April 2012