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Estuaries in NSW

Wallaga Lake


Tidal Data Summary

This page show a summary of Tidal Data for this estuary that has been collected under the Estuary Management Program and its predecessors, in conjunction with Manly Hydraulics Laboratory (See MHL Report-1200, June 2004).

Tidal Prism Measurements

The Tidal Prism is the volume of water that flows into (Flood) and out of (Ebb) the estuary during a tide. This of course depends on the tidal range (difference between high and low water during the day of measurement. It also depends on where the measurements are taken.

The following table shows the measured Tidal Prism at the location closest to the entrance of the system, along with the Tidal Range for near the measurement site and at Fort Denison, Sydney Harbour.

 
Location 1.5km from the entrance at the road bridge on 29/3/95

 

Tide State Flow Local Fort Denison
(106 m3) Tidal Range (m) Tidal Range (m)
Flood Flow 0.38 0.03 1.31
Ebb Flow 0.4 0.05 1.35
 

Tidal Survey Reports

A Tidal Survey is a measurement program run over at least one full tidal period, that is, approximately 12.5 hours. Over this time, tidal characteristics are measured at a number of locations in the estuary consecatively. The tidal characteristics measured include tidal flow and velocity, water levels, and physical water quality characteristics such as salinity, temperature, disolved oxygen, pH and turbidity.

The following table outlines the Tidal Surveys that have been undertaken on this estuary, when it was done, a simple description of what was measured and the MHL Report that can be used for further reference. For the most comprehensive survey, a map shows the location and plots of the flows and water levels measured.

 
Date Data Collected Figure MHL Report
1995-03-27 Water levels at 10 locations, discharge at one line, water quality profiling and drogue tracking. Entrance very constricted. pdf MHL725
2000-01-01 Meads Bay Water Quality Monitoring 2000-01 MHL1048
 

Water Level Data

This table shows the Current and Historical Sites for Real Time Water Levels measurements. The date of commencement for the records are noted in brackets. All data for these sites can be obtained through Manly Hydraulics Laboratory.

 
Sites
Current Wallaga Lake (August 1993) and Regatta Point (October 1993).
Historical Meads Bay.

Water Quality Data

This table shows the Current and Historical Sites for Real Time Water Quality measurements. The date of commencement for the records are noted in brackets. All data for these sites can be obtained through Manly Hydraulics Laboratory.

 
Sites
Current No data.
Historical Meads Bay. Temperature/salinity data collected in conjunction with the tidal gaugings (see above).