Traditionally, drillers and hydrogeologists only have a somewhat limited idea of what lies beneath their feet. This knowledge is based on years of experience that teaches them that at a certain depth (more or less) will lie an aquifer with reasonable quality and quantity. By and large, because drilling is expensive, if a suitable aquifer is found most people stop drilling rather than continuing downwards on the hope of something better. Therefore great discoveries can remain unknown.

An example of this dilemma from the Penola Trough can be seen in the figure below.

Example of the benefit of knowing the geofabric before you drill. Shallow bores in the Dilwyn Formation stop just short of a high yielding unit.Because of its relatively high yield and low salinity, the Dilwyn Formation is a major target for town water supplies and other high value users. Bores 7023-3674 and 7023-1849 both penetrate into the Dilwyn Formation.

However, analysis of the geofabric using seismic and other techniques shows that the Dilwyn Formation is actually composed of multiple aquifers each with its own characteristics.

Just below where the bores stopped is a middle unit in gold. Which is a cleaner sand with a higher hydraulic conductivity and yield. Also of note is the complex nature of the geofabric due to both faulting and variation with the thickness of individual units.

All of this complexity is completely unmappable using borehole information alone. There are only a handful of bores deeper than 100 metres and none of them penetrate more beyond 400 metres.

The answers lie in the geofabric.