Improvements to the model

Hunter River Salinity Trading Scheme Performance Report 2024–25.

Flow modelling/forecast results during the events closely matched the observed flows, which resulted in accurate TAD estimates however further upgrades (as well as proposed upgrades), were made by WaterNSW, and are outlined below.

Hunter River downstream (D/S) of Glenbawn Gauge

In 2024–25 ‘Hunter River D/S of Glenbawn Dam’ gauge was added to the model as a tributary inflow location. High volume releases from the dam, such as evacuating the flood mitigation zone/capacity of the dam, can trigger a discharge event, and adding Hunter River D/S of Glenbawn Dam to the model allows the model to consider the impact of these releases in determining the flow forecasts.

Revised River Registers

Improved messaging has been included in the river register to provide more information regarding the possibility of a revised register for a particular block during an event.

Rainfall Runoff Model

Further improvement to the Scheme model could be made by incorporating a rainfall runoff model to accurately forecast the runoff generated by the observed rain in the tributary catchments which join the Hunter River. This would provide potential benefit by increasing the discharge opportunities available to scheme participants. particularly in the upper sector, where discharge opportunities are generally limited. WaterNSW has submitted a proposal to develop rainfall runoff model to EPA which is currently under review.