Perth
17.12 Entitled diversion of allocated surface water to urban water system

This line item volume (91,792 ML) represents the total surface water diverted for urban water supply in the Perth region during the 2012–13 year.

Total volume of water diverted from each surface water resource to the urban water system during the 2012–13 year is given in the following table.

Surface water made up approximately 28% of the inflows to the urban water supply system during the 2012–13 year, which is similar to the previous year's contribution of 81,533 ML (approximately 26% of the urban water supply).

Operational Data Storage System and the Water Corporation Annual Report 2013.

Total water abstracted from surface water storages for urban water supply within the Perth region is equal to the total annual water released from the storages during the year. The water volumes released from the storages are metered at the outlet continuously and reported on a monthly basis.

The volume of water diverted from the Murray River for supply to Dwellingup was not measured during the 2012–13 year. The total water allocation for Dwellingup is 167 ML (see line item 21.2 Surface water allocation announcements – urban water system); therefore, it is likely that the reported volume of surface water diverted to the urban water supply system is slightly underestimated.

Expected error for water meters is +/– 5%.

The Department of Water requires that all water meters, when tested under in situ conditions, must be within 5% accuracy across the full flow rate range (Department of Water 2009c).