Adelaide
17.6 Surface water diversions – other statutory rights

Supporting information

The volume reported (2,230 ML) represents non-licensed surface water diversions in the Western Mount Lofty Ranges (WMLR) Prescribed Water Resources Area (PWRA) for all purposes except the supply of the Adelaide metropolitan area by SA Water. The water allocation plan (WAP) for this area was at draft stage during the 2011–12 year and surface water diversions did not require a licence to divert and use water; instead the right to divert surface water is provided for under a notice of prohibition section 132 of the Natural Resources Management Act 2004 (South Australia).

For further information on these water rights, see the Water rights section in the 'Contextual information' and line item 32.1 Other statutory surface water rights.

When the WAP is adopted for the WMLR PWRA it will cover the following prescribed watercourses: Gawler River, Little Para River, River Torrens/Karrawirra Parri River and Onkaparinga River.

Quantification approach

Data source

South Australian Department of Environment, Water and Natural Resources (DEWNR): unpublished field survey.

Provided by

DEWNR.

Method

The total maximum potential watercourse diversion demand for the WMLR PWRA within the Adelaide Region was derived from a survey of existing users within this PWRA. It includes the planned maximum potential watercourse diversion demand by SA Water (80,000 ML) to supply the Adelaide metropolitan urban water system. The remaining maximum potential watercourse diversion for other users, currently made available under a notice of prohibition, has been adjusted by an estimate of actual diversion. This estimate is based on the actual watercourse diversions in the Barossa PWRA  in the 2011–12 year,  expressed as a percentage of the watercourse allocations (40%). This percentage was applied to the maximum potential watercourse diversion for other users to obtain the line item volume. The following tables detail the operations that were performed. 

Non-licensed surface water diversions in the WMLR PWRA for the 2011–12 year

Operation

Item

Volume (ML) / percentage

 

Total maximum potential watercourse diversion in WMLR PWRA:

85,576

less

Maximum potential watercourse diversion: SA Water

80,000

 

Maximum potential watercourse diversion: other users

5,576

multiply by

Percentage of watercourse allocation diversion in Barossa PWRA

40%

 equals

17.6 Surface water diversions – other statutory rights

2,230

 

Percentage of watercourse allocation diversion in the Barossa PWRA for the 2011-12 year

Operation

Item

Volume (ML) / percentage

 

17.11 Entitled diversion of allocated surface water to users

1,116

divided by

21.1 Surface water allocation announcements

2,774

 equals

Percentage of watercourse allocation diversion in Barossa PWRA

40%

Assumptions, limitations, caveats and approximations

The Barossa climate, management practices, mix of available water sources and water intensive industries are quite different to the WMLR PWRA. Extrapolation of changes observed in the Barossa PWRA compared to the WMLR should only be considered as an indication of annual surface water diversions.

Uncertainty information

The uncertainty estimate was in the range of +/– 30–50%.

Comparative year

This line item corresponds to line item 17.6 'Diversions - other statutory rights' reported in the 2011 Account.