3.1 Urban water supply system
The volume reported (1,414 ML) represents the total volume of water held in held in pipes and tanks that make up SA Water's potable water supply system at 30 June 2013.
Major pipelines used to transfer River Murray water into the region are included in the calculation of the pipes volume.
The following table presents the volume of urban water held, and is itemised by pipes and tanks.
|Urban water supply system||Storage volume at 30 June 2013 (ML)||Storage volume at 30 June 2012 (ML)|
Geographic Information System (GIS) database, storage tank register, and Maximo system.
GIS analysis was used to identify potable water tanks and pipes within the Adelaide region. The volume of water in these tanks and pipes is estimated from their total capacity.
The volumes of water held in tanks were collected from SA Water's storage tank register and Maximo system.
The volumes of water held in pipes were estimated from pipe lengths and nominal diameters (stored in the Maximo system) using the following formula:
π x (D/2) x (D/2) x PL
D = Nominal diameter of the pipe
PL = Pipe length.
Some tanks did not have volumes recorded in the database (< 5%). Queries with key staff obtained these volumes.
Assumptions, limitations, caveats and approximations
- Given the small variation between reporting years, it was assumed that the pipe length and tank volume remained unchanged in the 2012–13 year, compared to the 2011–12 year.
- Process tanks and pipes are assumed to be 100% full in winter, while balancing tanks were assumed to be 50% full.
- Pipes without recorded construction dates are assumed to have been constructed before the 2012–13 year. It is assumed that all tanks without construction dates were constructed before the 2012–13 year.
- Only tank and pipe assets that are owned by SA Water are included in the calculation.
- Nominal diameters of pipes were used to calculate volumes.
- Fire service mains pipe assets are not included; however the volume was negligible (<1 ML).