Groundwater salt accessions to land in the Queensland Murray-Darling Basin, Australia

Salt accessions from artesian and sub-artesian bores have been calculated for the Queensland Murray-Darling Basin (QMDB), Australia, using available water chemistry, licensing data and a number of assumptions. The majority (~90%) of the salt accessions come from sub-artesian bores used for irrigation (including intensive livestock) purposes. Historically, free-flowing artesian bores in the west of the basin have contributed large quantities of salt, but their contributions have declined with capping and piping of these bores. The highest salt yields (t/km²) are in the Condamine catchment, which also contains 70% of the bores in the region. Groundwater salt accessions are considerably less than atmospheric (rainfall) accessions in all catchments except the Condamine. Further expansion of the coal seam gas industry may substantially increase non-cyclic groundwater accessions, further reducing catchment salt export/import ratios.