This line item consists of the combination of line items 14.6.5.4 Diversion of unregulated flows – urban holder and 14.6.2 Diversion of unregulated flows – urban water access entitlement.
The table below shows the components that contribute to the unregulated inflow of surface water into the urban water supply system during the 2009–10 reporting period.
| Diversion | Line item | Volume (ML) |
|---|---|---|
| Off-grid town diversions | 14.6.5.4 | 4,250 |
| Unregulated diversion to WTP managed by Seqwater | 14.6.2 | 14,008 |
| Total SEQ region | 18,258 |
WTP = water treatment plant
This line item comprises two different data-sets. The method for each data-set is shown below.
Queensland Department of Environment and Resource Management (DERM).
DERM obtained metered water treatment plant (WTP) output and/or diversion data from the various regional councils within the South East Queensland (SEQ) region that supply urban water to communities not connected to the Water Grid (off-grid townships).
Derived from measured data. DERM reliability and accuracy rating is A2 (see glossary).
Some communities not connected to the Water Grid were not included. Communities with a population of less than 50 were not captured and reported. Off-grid communities within the Gold Coast water resource plan (WRP) area were therefore not captured.
DERM has accepted these measured values from regional councils in good faith.
Seqwater database.
Seqwater.
Seqwater provided WTP output volume and WTP source for WTPs that Seqwater manage. Where the source water was not part of a water supply scheme (WSS), it was assumed that diversion was through the unsupplemented water licences held by the SEQ Water Grid Manager.
Ungraded.
The assumption that all WTPs managed by Seqwater that source water outside of the WSS were unsupplemented water licences held by the SEQ Water Grid Manager may not be strictly true. Although no double counting occurs, there may be a slight misrepresentation of data between line items 14.6.2 Diversion of unregulated flows – urban water access entitlement and 14.6.5.4 Diversion of unregulated flows – urban holder.
The volume reported for surface water diversions to WTPs does not consider water loss in the raw water trunk mains or through the treatment processes. Therefore, the volume reported may be a slight underestimate of water extracted from the source.