Until the outcome of the 2025 federal election, the Australian Government is operating under caretaker conventions

Perth
17.4 Surface water leakage to landscape

Supporting information

The volume reported in the water accounting statements (142 ML) represents the total volume of seepage from surface water storages within the Perth region to the landscape during the 2012–13 year.

The total annual seepage at each storage, where seepage data are collected, during the 2012–13 year is given in the following table.

 

Total seepage from each storage within the Perth region during the 2012–13 year

Storage

Seepage

(ML)

Canning

9

Churchman Brook

11

North Dandalup

20

Serpentine Head

31

South Dandalup

5

Stirling
27

Victoria

15

Wungong

24

Total

142

 

Quantification approach

Data source

Operational Data Storage System.

Provided by

Water Corporation.

Method

Instantaneous seepage data (L/s) are measured at surface water storages within the Perth region on an approximately daily basis. These data were inputted to Hydstra and converted to daily volume data (ML) to determine the total annual seepage (in ML) at each storage.

Assumptions, limitations, caveats and approximations

Seepage data are only collected at approximately half of the storages within the Perth region. It is assumed that no seepage has occurred at the remaining unmetered storages. Consequently, the reported leakage volume is likely to be an underestimate.

It is assumed that the dam seepage measuring points reflect the total seepage from the storages.

These data were not quality coded. Significant spikes in the data (i.e. where daily data were orders of magnitude different to daily data collected before and after the spike) were removed from the datasets for the calculation of total seepage volume.

Uncertainty information

The uncertainty estimate was not quantified.