Depth to groundwater

The depth to groundwater dataset is a gridded interpolation of depth to groundwater. The dataset is a raster grid, with 50 × 50 m pixels holding values that represent the probable maximum depth in metres to the phreatic water table. This represents the likely lowest water level, under natural conditions, in an open well or borehole drilled into the uppermost parts of a rock unit. The dataset has been modelled from topography and hydrology, assuming that surface water and groundwater are hydraulically connected. It has not used observations of groundwater level in wells or boreholes directly, but they have been used to validate its performance.

Groundwater plays a key role in many shallow geological processes and an estimate of the level of the water table is an important component of site investigations, assessments of water resources and environmental studies. Data on groundwater level is frequently used as a component within geological models, for example in studies of slope stability, groundwater flood susceptibility or the suitability of an area for sustainable urban drainage systems.