Annual entitlement for the Condamine floodplain irrigators – is it really working?

Annual entitlement for the Condamine floodplain irrigators – is it really working?

Rigorous analysis of monitoring bores hydrographs demonstrates that since 2008 the water table in the central part of the Condamine Floodplain has stabilized, ending several decades of a consistent decline in groundwater levels. It seems that the stabilization is a result of the 2007 revised water pumping restrictions scheme in the Condamine Groundwater Management Area (CGMA). Prior to 2007, water allocations were set only at the heart of the ‘cotton land’, between Pampas and Macalister, where the focal of groundwater drawdowns was observed. However, this measure had no noticeable impact on groundwater levels. From that year onward, water allocations were also set at the peripheral parts of the CGMA, including the southern part (‘sub-area 4’). In this area, groundwater from the upper alluvial valleys, as well as large parts of the basaltic ridges, merge and flow laterally toward the central alluvial aquifer. In other words, pumping reduction in the southern area resulted in an increase in the lateral flow toward the central area, which act to compensate and prevent further drawdowns. These observations emphasis the need in integral water management for the entire floodplain, including target values for sustainable yield for different zones within the basin. Further monitoring and modelling could assist this task.

Abstract only published in Proceedings.
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