2.1.4 Surface water hydrology and water quality

Summary

This section summarises key datasets that are used in surface water modelling of the Namoi subregion. Streamflow data from 37 gauging stations are used in the rainfall-runoff model Australian Water Resources Assessment (AWRA) landscape model (AWRA-L) and the river routing model (AWRA-R). The available median streamflow data length is 47.5 years while three-quarters and one-quarter of the stations have at least 36 and 71 years of data available, respectively. Only 30 years of data from 1983, available for all but six catchments, were used in the rainfall-runoff modelling. Apart from the Namoi River, all other rivers and creeks are ephemeral with a few flowing for less than 50% of the time. Streamflow data quality for all but four stations is marked as predominately poor, unverifiable or missing. The highest maximum daily flow of 213,340 ML is observed for the Namoi River at Boggabri while the lowest daily maximum flow (1,731 ML) is observed for Pian Creek at Cubbaroo (an anabranch of the Namoi River) west of Wee Waa.