17.6 Surface water diversions – other statutory rights
The volume reported (2,006 ML) represents non-licensed surface water diversions in the Western Mount Lofty Ranges Prescribed Water Resources Area (PWRA) for all purposes during the 2012–13 year, except the supply of the Adelaide metropolitan area by SA Water (reported at line item 17.12 Entitled diversion of allocated surface water to urban water system).
Non-licensed surface water diversions are managed by authorisations under sections 128, 132 and 164N of the Natural Resources Management Act 2004 South Australia). For further information on these authorisations, refer to the Water entitlements and other statutory water rights section of the 'Contextual information'.
South Australian Department of Environment, Water and Natural Resources (DEWNR): Internal database extract of maximum potential watercourse diversion in the Western Mount Lofty Ranges; Bureau of Meteorology: calculations of non-metered surface water diversions.
DEWNR; Bureau of Meteorology.
Non-licensed surface water diversions in the Western Mount Lofty Ranges were calculated by estimating the percentage of allocated surface water diverted in the Barossa PWRA, then applying this percentage to the maximum potential watercourse diversion for other users in the Western Mount Lofty Ranges. This calculation is summarised in the following table.
|Calculation||Line item||Volume (ML)|
|17.11 Entitled diversion of allocated surface water to users||1,010|
|divided by||21.1 Surface water allocation announcements (for the Barossa PWRA)||2,779|
|equals||percentage diversion of allocated surface water in the Barossa PWRA||36.34%|
|multiply by||maximum potential watercourse diversion for other users1||5,519|
|equals||17.6 Surface water diversions – other statutory rights||2,006|
1 Data sourced from DEWNR database extract of maximum potential watercourse diversion in the Western Mount Lofty Ranges.
Assumptions, limitations, caveats and approximations
The Barossa climate, management practices, mix of available water sources, and water intensive industries are quite different to the Western Mount Lofty Ranges PWRA. Extrapolation of changes observed in the Barossa PWRA compared to the Western Mount Lofty Ranges should only be considered as an indication of annual surface water diversions.
The uncertainty estimate was in the range of +/– 30–50%.