Numerical modelling will not be undertaken in the Sydney Basin bioregion. Consequently, detailed reporting of current water accounts is not required. Instead, the sources of water information that would be useful in compiling a water account for the Sydney Basin bioregion are summarised.
The Bureau of Meteorology is the national custodian of water information for Australia. For the Sydney Basin bioregion, the main data providers are DPI Water (formerly the NSW Office of Water) and WaterNSW (formerly Sydney Catchment Authority and State Water Corporation). Under the Commonwealth’s Water Act 2007, these and other named agencies supply the data they collect to the Bureau’s national water information system.
The Bureau of Meteorology is mandated to produce a National Water Account (NWA). Currently there are ten major water-using regions for which annual water accounts are prepared. The NWA for the Sydney region covers much of the same area as the Sydney Basin bioregion and is a key source of water availability, water use and water management information for the bioregion. Water accounting for the Sydney region has been undertaken annually since 2009–10.
Groundwater is a relatively small proportion of total water use in the Sydney region and there are generally less groundwater data available from which to construct a water account for the Sydney region. The NWA for the Sydney region does not report groundwater volumes.