Perth
4.1 Irrigation water supply system

Supporting Information

This line item refers to the volume of water in the irrigation scheme's distribution pipe network.

Quantification Approach

Data Source

Harvey Water: Geographic Information System Asset database.

Provided by

Harvey Water.

Method

The volume of water within the irrigation water supply system (370 ML) was calculated by summing the volume of each section of the system. The entire irrigation system is a network of pipes. Therefore, the total volume of water within the irrigation system is the sum of the volumes of each section of pipe within the system.

The volume of a section of pipe is the product of the length of the pipe section (km) and the cross sectional area of the pipe (m2).

Assumptions, Limitations, Caveats and Approximations

It is assumed that all the pipes in the irrigation water supply system are at full capacity and have uniform diameter. Unless the pipe network is augmented or partly decommissioned, it is likely that this line item will always be 370 ML.

Uncertainty Information

This value is estimated to be in the range of +/– 5–10%.

Comparative year

The following table presents substantive changes in the line item reported in this 2011 Account with the corresponding line item in the 2010 Account.



Comparative year information for line item 4.1

2011 Account line item

2010 Account line item

2011 Account volume at 30 June 2010 (ML)

2010 Account volume at 30 June 2010 (ML)

Change from the 2010 Account to the 2011 Account

4.1 Irrigation water supply system

5.4 Irrigation water supply system

370

370

Change in line item number