Adelaide

The value reported in the water accounting statement (4,567 ML) comprises surface water diversion for irrigation and industrial/commercial purposes including diversions from the Barossa and Western Mount Lofty Ranges prescribed water resource areas (PWRAs). The breakdown of surface water diversions by management area and purpose are shown in the table below.

NA = Not applicable

Data source

South Australian Department for Water (DFW): Water Information and Licensing Management Application (WILMA) and unpublished surface water requirement databases.

Data provider

South Australian Department for Water.

Method

Barossa PWRA

Metered surface water diversion for 2009–10 was obtained from the WILMA licensing database for the Barossa PWRA. Some surface water diversions in the Barossa PWRA are unmetered. The metered diversion in the Barossa was increased by 20% to account for any unmetered diversion (DFW, Water Planning and Management, pers. comm., 2010).

Western Mount Lofty Ranges PWRA

For the remaining areas, surface water diversions were estimated based on a modification of the expected water requirements at known extraction points located on rivers in the Western Mount Lofty Ranges PWRA, including the rivers flowing across the Adelaide Plains. This information was sourced from an unpublished DFW database that is used for determining surface water demands.

Uncertainty

Ungraded.

Assumptions, approximations and caveats/limitations

This line item does not include surface water diversions that are:

• covered by the Penrice Exemption to the Natural Resources Management Act 2004 for stock and domestic supply throughout the Adelaide Region.

This method is based on the following assumptions:

• Unmetered surface water diversion in the Barossa PWRA was assumed to equate to 20% of total diversions.
• For prescribed watercourses, it is assumed that 100% of metered surface water diversions with an irrigation allocation were used for irrigation.
• All surface water diversions outside the Barossa PWRA are assumed to occur in the Western Mount Lofty Ranges PWRA, including prescribed watercourses across the plains (i.e. Gawler River, Little Para River, River Torrens and Onkaparinga River).
• It is assumed that all surface water diversions outside the Barossa PWRA are used for irrigation.
• The database used for determining the surface water demands in the Western Mount Lofty Ranges PWRA relates to the water use during 2009–10.
• The unpublished database assists the determination of reasonable water requirements in the Western Mount Lofty Ranges PWRA. The allocation process considers other information that has not been considered in estimating this line item.