17.4 Leakage to landscape

Supporting information

The volume recognised in the water accounting statements (19 ML) represents the total leakage from surface water storages within the Ord region to the landscape.

The total annual seepage at each storage where seepage data are collected during the 2011–12 year is given in the following table.

Total seepage from each storage within the Ord region during the 2011–12 year




Lake Argyle


Lake Moochalabra




Quantification approach

Data source

Operational Data Storage System.

Provided by

Water Corporation.


Instantaneous seepage data (L/s) are measured at storages within the Ord 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 Lake Argyle and Lake Moochalabra within the Ord region. It is assumed that no seepage has occurred at the remaining unmetered storages. Consequently, the reported leakage volume of 19 ML is likely to be an underestimate.

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

Uncertainty information

The uncertainty estimate was not quantified.