Implementing Daily Salinity Models in the NSW Murray Darling Basin Tributaries

The NSW Salinity Strategy and Murray Darling Basin Ministerial Council (MDBMC) Basin Salinity Management Strategy (BSMS) were developed to manage salinity in response to the findings of the 1999 Basin Salinity Audit. To understand and assess the linkage between land use change at the property scale, and the salinity response within the river system. A suite of landscape, instream, and socioeconomic modelling tools is being developed for this purpose. The instream component of the resultant modelling suite integrates salinity to the Integrated Quantity Quality Models (IQQMs) developed for daily water balance for the NSW Water Reforms and Murray Darling Basin Commission (MDBC) Cap. The objective was to produce a daily time series of salinities at key points within these river systems under current and future salinity management scenarios. The salinity modules of the IQQMs were implemented in three stages. The first stage included extensive quality assurance and refinement of the software, and a full assessment of available data. The second stage involved converting the prior work done for the salinity audit into the IQQMs, including revising the system schematics, and evaluating the results against observed data. A third conditional stage allows for model revision subject to the outcomes of this evaluation. This model implementation process has improved the understanding of, and linkages between, salt and water balance in the NSW tributaries, and set a platform to enhance capabilities in other areas of water quality modelling.