Perth
42.3 Leakage from storages

Supporting Information

This line item refers to leakage from surface water storages within the Perth region that supply water to the urban water system.

The total annual seepage at each storage, where seepage data are collected, during the 2010–11 year is given in the following table.

 

Total seepage from each storage within the Perth region during the 2010–11 year

Storage

Total seepage

(ML)

Canning

12

Churchman Brook

11

North Dandalup

13

Serpentine Head

25

South Dandalup

5

Victoria

6

Wungong

18

Total

90

 

Quantification Approach

Data Source

Water Corporation: Operational Data Storage System.

Provided by

Bureau of Meteorology.

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 of 90 ML 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.