Perth

This line item consists of two types of inflows to major reservoirs within the Perth region:

1. transfer of water from pumpback reservoirs into major urban supply reservoirs
2. transfer of water from the water distribution system to major urban supply reservoirs.

The volume of water transferred to urban supply reservoirs from each pumpback reservoir during 2009-10 is given below. Water is collected in pumpback reservoirs on an opportunistic basis and transferred back to the main urban supply reservoirs to settle (i.e. reduce turbidity) and become part of the water supply source for that reservoir.

The volume of water transferred to urban supply reservoirs from the water distribution system during 2009-10 is given below. The water transferred from the water distribution system is a combination of surface water, groundwater and desalinated water. These internal water transfers occur to store desalinated water and groundwater produced during winter, and to balance the reservoirs to prevent overflow and enable summer peak supply capacity.

IWSS = Integrated Water Supply Scheme

(1) Water transfer to Victoria Reservoir is via Bickley Pumpback Reservoir

Data source

Water Corporation: Operational Data Storage System database.

Data provider

Water Corporation.

Method

There were two other water transfers into surface water reservoirs within the Perth region during 2009-10. In both cases, the total volume of water transferred is based on measured inflow data at the major reservoirs.

Uncertainty

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

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

Approximations, assumptions, caveats/limitations

Nil