Ord
18.11 Groundwater allocation extraction

Supporting Information

The volume recognised in the water accounting statements (7,912 ML) represents the allocation extracted for groundwater entitlements in the Ord region during the 2010–11 year.

During the 2010–11 year, the Western Australian Department of Water administered 33 licences in this category. Licences relate to water sourced from the Canning–Kimberley groundwater area.

Quantification Approach

Data Source

Western Australian Department of Water: Water Resource Licensing database. Annual Reports/Meter Card readings from licensees.

Provided by

Western Australian Department of Water.

Method

The volume presented for this line item is a combination of metered data and estimates.

Where metered data are available, the abstraction is calculated as the actual abstraction for the 2011 Account. Where metered data are not available, the volume of abstraction is estimated to be the full annual entitlement, divided by the number of days that each licence was active for the 2011 Account. The number of days the licences were active is calculated using the annual renewal date of each individual licence:

  • for licences that expired during the reporting year, the volume of abstraction is estimated to be the full entitlement, divided by the number of days from 1 July 2010 until its expiry date
  • for new licences that were created during the reporting year, the volume of abstraction is estimated to be the full entitlement, divided by the number of days from the licence start date until 30 June 2011.

Some licences are issued in perpetuity and do not have an annual renewal date. In these cases, the volume of abstraction is estimated to be the amount of one full year's allocation for licences in force during the reporting year.

Assumptions, Limitations, Caveats and Approximations

There is not sufficient information relating to actual abstraction to provide more accurate estimates of abstraction for all licences. The pro-rata estimates of abstraction assume that the full annual entitlement is abstracted each year and that the rate of abstraction is uniform throughout the year. It is unlikely on both counts that this will be the case for all licences.

For licences that are metered, the licencee is required to install a cumulative water meter of a type approved under the Rights in Water and Irrigation (Approved Meters) Order 2009 for each water draw point under the licence. The licencee must ensure the installed meter(s) accuracy is maintained to within +/–5% of the volume metered, in field conditions.

Meters must be installed in accordance with the provisions of the Guidelines for Water Meter Installation (Western Australian Department of Water 2009).

Uncertainty Information

For estimated data: uncertainty is not quantified.
For measured data: uncertainty range +/–5%.

Comparative year

The following table compares the value for the 2009–10 year reported in this account with the corresponding value reported in the 2010 Account.

Comparative year information from the 2010 Account for line item 18.11

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

18.11 Groundwater allocation extraction

16.5.3.7 Groundwater allocation extraction – other lumped holders

6,276

6,276

Change in line item name and number