20.3 Leakage to groundwater

Supporting information

This line item volume (0 ML) represents the leakage from the irrigation water supply system into groundwater aquifers within the Perth region during the 2012–13 year.

Quantification approach

Data source

Supervisory Control and Data Acquisition System.

Provided by

Harvey Water.


Leakage from the irrigation water supply system is not measured. The volume is estimated as total water inflow into the system (line item 12.9 Entitled diversion of allocated surface water to irrigation scheme) minus the volume of water supplied to the various consumers of the Harvey Water Irrigation Scheme (line item 20.4 Delivery to irrigation scheme users). Where the volume of water supplied to consumers is greater than the volume of water diverted into the system, it is assumed that no leakage has occurred during the year. 

Assumptions, limitations, caveats and approximations

There is no differentiation between leakage to the landscape and leakage to the groundwater store, it is simply assumed in this case that all losses go to the groundwater store.

It is assumed that most of the losses in the irrigation water supply system are attributed to metering error rather than actual leakage from the system.

Uncertainty information

The uncertainty estimate was not quantified.