The Benmorven area is underlain by the most highly confined of the Southern Valleys' aquifers and contains the oldest groundwater, with the lowest yielding wells.
A variety of end users rely on groundwater including rural residential subdivisions, vineyards, a winery and golf course.
Aquifer levels fell further than elsewhere in the Southern Valleys' aquifers during the 1998 and 2001 droughts.
The reason for the high degree of confinement is the presence of a thick layer of marine muds which overlies the aquifer-forming gravels. Historically, most deeper wells were free-flowing above ground level, but pressures have fallen since 1998.
The geology is complex, resulting in several aquifer pockets and a vertical sequence of water-bearing layers.
This is illustrated by the red arrow in the photo showing the natural level of the groundwater at Morven Lane in 1990. Levels are currently 3 to 4 metres below the surface.