Perth

Data source

Water Corporation: Facilities Mapping System database.

Data provider

Water Corporation.

Method

The storage volume of the urban potable water supply system is comprised of two components: the distribution pipe network (5,442 ML) and the service reservoirs (1,500 ML).

Distribution pipe network

The volume of water within the urban distribution pipe network was calculated using a geographic information system (GIS) layer of the pipe network. The attributes of the GIS layer were used to select trunk mains and pipes used for distribution and reticulation. Only those features that are actively used for the potable network were selected.

The total volume of water within the system was calculated by summing the volume of each section of pipe within the system, as follows:

Total volume = 

where: L is the length of the pipe section (km), A is the cross-sectional area of the pipe (m²) and n is the number of pipes.

Service reservoirs

The volume of water within the service reservoirs of the urban supply system is measured on a daily basis at each reservoir. The total storage volume in these service reservoirs changes relatively little throughout the year.

Uncertainty

It is estimated that the uncertainty about the storage volume within the service reservoirs is +/- 10%.

Approximations, assumptions, caveats/limitations

• This value is an estimate of the volume of water within the delivery system of the Integrated Water Supply Scheme boundary. That is, it does not include water stored in the urban supply system for regions outside of the Perth metropolitan area (e.g. Mandurah).
• It is assumed that all the pipes in the urban potable water supply system are at full capacity and have a uniform diameter.