Sydney
17.11 Entitled diversion of allocated surface water to users

Users diverted 37,046 ML from streams in the Sydney region during the 2012–13 year.

Diversions in this line item are made under water access licences in the Sydney region as specified in line item 21.1 Surface water allocation announcements.

Delta Electricity diverted 18,271 ML from Thomsons Creek Reservoir, Lake Lyell, and Lake Wallace for the Mt Piper and Wallerawang power stations. The New South Wales Office of Water estimated the diversions from 'individual stock and domestic' and 'other lumped holder' water access entitlements.

Details of the water rights associated with these diversions can be found under Water access and use information.

The following table provides a breakdown of the diversions made under this category.

Volume of water diverted from surface water by entitlement holders during the 2012–13 year

Entitlement  holder	Water source	Water diverted during 2012–13 (ML)
major utility (power generation)	Cox River	18,271
individual holder for stock and domestic	Hawkesbury and Lower Nepean rivers	2401
other lumped holders	Hawkesbury and Lower Nepean rivers	18,5352
Total		37,046

^1–2 Estimated by the New South Wales Office of Water

Delta Electricity Annual Report 2013.

Delta Electricity.

The volumetric value estimated for the diversion of allocated flows for the industrial and commercial holder category was derived from the Delta Electricity Annual Report 2013 and the volume stated for the entitlement was derived from Delta Electricity's water management licence.

The diversion stated by Delta Electricity was taken from their Delta Electricity Annual Report 2013.

The volume is based on estimated data. The uncertainty associated with this volume is +/- 100%.

Water Sharing Plan for the Greater Metropolitan Unregulated River Water Sources and water use records in the spreadsheets managed by licensing field officers of the New South Wales Office of Water.

New South Wales Office of Water.

Water use was estimated by applying a 15% entitlement-use factor for the 2012–13 year to the total entitlement value for the categories of 'individual stock and domestic' and 'other lumped holders' (see line item 21.1 Surface water allocation announcements). The entitlement-use factor is based on metered usages from 75% of total unregulated and domestic and stock access licence holders in the Hawkesbury-Nepean system.

The calculation method is applied only to the categories of 'individual holder for stock and domestic' and 'other lumped holders' from unregulated flow for the 2012–13 year. The metered area (used to calculate entitlement-use factor) represents only a sample of the Sydney region. The sample includes 204 licences in the Hawkesbury and Nepean catchment representing 21% of the total entitlement for that catchment.

The volume was estimated. Estimated uncertainty is +/– 30% to 50% based on professional judgement and established practice within the New South Wales Office of Water.