2.1.4.4 Gaps

The stream gauges have a relatively long data record with few missing records. However the majority of the catchments have poor or unverified data making the results of rainfall-runoff modelling less reliable. This will have obvious large implications for uncertainty in the streamflow data leading to uncertainty in the modelling results.

The limited number of stream gauges in unregulated rivers in the Namoi river basin limits the number of catchments that can be used in the calibration, thus it may affect the reliability of the model outcome.

One of the gaps in the surface water modelling relates to the creation of model nodes in the link-node network where there are no observations of streamflow or river geometry. The approach used to derive cross-sections and the estimates of streamflow from AWRA-L should not significantly impact predictions of the differences in hydrological response variables due to the additional coal resource development (ACRD), because they are represented the same way in both baseline and the coal resource development pathway (CRDP).

Water quality data including the salinity data were not analysed in this section as those were not modelled in the BA.