12.1  Piezometric levels in deep aquifers

DLWC measures piezometric levels in the Calivil and Renmark formations (generally greater than 70 metres in depth from land surface).  These figures were supplied to CICL and, using ArcView and Spatial Analyst, were used to produce Figure 12.1. Groundwater readings for each year were selected from June, July, August or September; whichever month had the least piezometric depth from the surface.  Where readings were not available for any of these months, an October reading was used. The Coleambally LWMP contains a target of reducing the piezometric levels in the Calivil formation to below 14 metres.

Figure 12.1  Calivil piezometric level

Table 12.1 contains a summary of the deep aquifer data for the area within the CIA boundary from 1997 to 2000 expressed as percentages of area.  This table shows that since 1999 the area of the CIA with a piezometric level of 14 metres or less has substantially improved.

Table 12.1  Calivil piezometric level summary for the CIA